diff options
Diffstat (limited to 'fs/btrfs/extent_io.c')
| -rw-r--r-- | fs/btrfs/extent_io.c | 3677 |
1 files changed, 1494 insertions, 2183 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 61594eaf1f89..849199768664 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -96,11 +96,20 @@ void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info) */ struct btrfs_bio_ctrl { struct btrfs_bio *bbio; + /* Last byte contained in bbio + 1 . */ + loff_t next_file_offset; enum btrfs_compression_type compress_type; u32 len_to_oe_boundary; blk_opf_t opf; btrfs_bio_end_io_t end_io_func; struct writeback_control *wbc; + + /* + * The sectors of the page which are going to be submitted by + * extent_writepage_io(). + * This is to avoid touching ranges covered by compression/inline. + */ + unsigned long submit_bitmap; }; static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl) @@ -117,7 +126,7 @@ static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl) bio_ctrl->compress_type != BTRFS_COMPRESS_NONE) btrfs_submit_compressed_read(bbio); else - btrfs_submit_bio(bbio, 0); + btrfs_submit_bbio(bbio, 0); /* The bbio is owned by the end_io handler now */ bio_ctrl->bbio = NULL; @@ -164,26 +173,10 @@ void __cold extent_buffer_free_cachep(void) kmem_cache_destroy(extent_buffer_cache); } -void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end) -{ - unsigned long index = start >> PAGE_SHIFT; - unsigned long end_index = end >> PAGE_SHIFT; - struct page *page; - - while (index <= end_index) { - page = find_get_page(inode->i_mapping, index); - BUG_ON(!page); /* Pages should be in the extent_io_tree */ - clear_page_dirty_for_io(page); - put_page(page); - index++; - } -} - -static void process_one_page(struct btrfs_fs_info *fs_info, - struct page *page, struct page *locked_page, - unsigned long page_ops, u64 start, u64 end) +static void process_one_folio(struct btrfs_fs_info *fs_info, + struct folio *folio, const struct folio *locked_folio, + unsigned long page_ops, u64 start, u64 end) { - struct folio *folio = page_folio(page); u32 len; ASSERT(end + 1 - start != 0 && end + 1 - start < U32_MAX); @@ -198,18 +191,17 @@ static void process_one_page(struct btrfs_fs_info *fs_info, if (page_ops & PAGE_END_WRITEBACK) btrfs_folio_clamp_clear_writeback(fs_info, folio, start, len); - if (page != locked_page && (page_ops & PAGE_UNLOCK)) - btrfs_folio_end_writer_lock(fs_info, folio, start, len); + if (folio != locked_folio && (page_ops & PAGE_UNLOCK)) + btrfs_folio_end_lock(fs_info, folio, start, len); } -static void __process_pages_contig(struct address_space *mapping, - struct page *locked_page, u64 start, u64 end, - unsigned long page_ops) +static void __process_folios_contig(struct address_space *mapping, + const struct folio *locked_folio, u64 start, + u64 end, unsigned long page_ops) { struct btrfs_fs_info *fs_info = inode_to_fs_info(mapping->host); - pgoff_t start_index = start >> PAGE_SHIFT; + pgoff_t index = start >> PAGE_SHIFT; pgoff_t end_index = end >> PAGE_SHIFT; - pgoff_t index = start_index; struct folio_batch fbatch; int i; @@ -222,45 +214,35 @@ static void __process_pages_contig(struct address_space *mapping, for (i = 0; i < found_folios; i++) { struct folio *folio = fbatch.folios[i]; - process_one_page(fs_info, &folio->page, locked_page, - page_ops, start, end); + process_one_folio(fs_info, folio, locked_folio, + page_ops, start, end); } folio_batch_release(&fbatch); cond_resched(); } } -static noinline void __unlock_for_delalloc(struct inode *inode, - struct page *locked_page, +static noinline void unlock_delalloc_folio(const struct inode *inode, + struct folio *locked_folio, u64 start, u64 end) { - unsigned long index = start >> PAGE_SHIFT; - unsigned long end_index = end >> PAGE_SHIFT; + ASSERT(locked_folio); - ASSERT(locked_page); - if (index == locked_page->index && end_index == index) - return; - - __process_pages_contig(inode->i_mapping, locked_page, start, end, - PAGE_UNLOCK); + __process_folios_contig(inode->i_mapping, locked_folio, start, end, + PAGE_UNLOCK); } -static noinline int lock_delalloc_pages(struct inode *inode, - struct page *locked_page, - u64 start, - u64 end) +static noinline int lock_delalloc_folios(struct inode *inode, + struct folio *locked_folio, + u64 start, u64 end) { struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); struct address_space *mapping = inode->i_mapping; - pgoff_t start_index = start >> PAGE_SHIFT; + pgoff_t index = start >> PAGE_SHIFT; pgoff_t end_index = end >> PAGE_SHIFT; - pgoff_t index = start_index; u64 processed_end = start; struct folio_batch fbatch; - if (index == locked_page->index && index == end_index) - return 0; - folio_batch_init(&fbatch); while (index <= end_index) { unsigned int found_folios, i; @@ -272,23 +254,23 @@ static noinline int lock_delalloc_pages(struct inode *inode, for (i = 0; i < found_folios; i++) { struct folio *folio = fbatch.folios[i]; - struct page *page = folio_page(folio, 0); - u32 len = end + 1 - start; + u64 range_start; + u32 range_len; - if (page == locked_page) + if (folio == locked_folio) continue; - if (btrfs_folio_start_writer_lock(fs_info, folio, start, - len)) - goto out; - - if (!PageDirty(page) || page->mapping != mapping) { - btrfs_folio_end_writer_lock(fs_info, folio, start, - len); + folio_lock(folio); + if (!folio_test_dirty(folio) || folio->mapping != mapping) { + folio_unlock(folio); goto out; } + range_start = max_t(u64, folio_pos(folio), start); + range_len = min_t(u64, folio_pos(folio) + folio_size(folio), + end + 1) - range_start; + btrfs_folio_set_lock(fs_info, folio, range_start, range_len); - processed_end = page_offset(page) + PAGE_SIZE - 1; + processed_end = range_start + range_len - 1; } folio_batch_release(&fbatch); cond_resched(); @@ -298,7 +280,7 @@ static noinline int lock_delalloc_pages(struct inode *inode, out: folio_batch_release(&fbatch); if (processed_end > start) - __unlock_for_delalloc(inode, locked_page, start, processed_end); + unlock_delalloc_folio(inode, locked_folio, start, processed_end); return -EAGAIN; } @@ -319,8 +301,8 @@ out: */ EXPORT_FOR_TESTS noinline_for_stack bool find_lock_delalloc_range(struct inode *inode, - struct page *locked_page, u64 *start, - u64 *end) + struct folio *locked_folio, + u64 *start, u64 *end) { struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; @@ -338,9 +320,9 @@ noinline_for_stack bool find_lock_delalloc_range(struct inode *inode, /* Caller should pass a valid @end to indicate the search range end */ ASSERT(orig_end > orig_start); - /* The range should at least cover part of the page */ - ASSERT(!(orig_start >= page_offset(locked_page) + PAGE_SIZE || - orig_end <= page_offset(locked_page))); + /* The range should at least cover part of the folio */ + ASSERT(!(orig_start >= folio_pos(locked_folio) + folio_size(locked_folio) || + orig_end <= folio_pos(locked_folio))); again: /* step one, find a bunch of delalloc bytes starting at start */ delalloc_start = *start; @@ -352,33 +334,33 @@ again: /* @delalloc_end can be -1, never go beyond @orig_end */ *end = min(delalloc_end, orig_end); - free_extent_state(cached_state); + btrfs_free_extent_state(cached_state); return false; } /* - * start comes from the offset of locked_page. We have to lock - * pages in order, so we can't process delalloc bytes before - * locked_page + * start comes from the offset of locked_folio. We have to lock + * folios in order, so we can't process delalloc bytes before + * locked_folio */ if (delalloc_start < *start) delalloc_start = *start; /* - * make sure to limit the number of pages we try to lock down + * make sure to limit the number of folios we try to lock down */ if (delalloc_end + 1 - delalloc_start > max_bytes) delalloc_end = delalloc_start + max_bytes - 1; - /* step two, lock all the pages after the page that has start */ - ret = lock_delalloc_pages(inode, locked_page, - delalloc_start, delalloc_end); + /* step two, lock all the folioss after the folios that has start */ + ret = lock_delalloc_folios(inode, locked_folio, delalloc_start, + delalloc_end); ASSERT(!ret || ret == -EAGAIN); if (ret == -EAGAIN) { - /* some of the pages are gone, lets avoid looping by + /* some of the folios are gone, lets avoid looping by * shortening the size of the delalloc range we're searching */ - free_extent_state(cached_state); + btrfs_free_extent_state(cached_state); cached_state = NULL; if (!loops) { max_bytes = PAGE_SIZE; @@ -391,20 +373,19 @@ again: } /* step three, lock the state bits for the whole range */ - lock_extent(tree, delalloc_start, delalloc_end, &cached_state); + btrfs_lock_extent(tree, delalloc_start, delalloc_end, &cached_state); /* then test to make sure it is all still delalloc */ - ret = test_range_bit(tree, delalloc_start, delalloc_end, - EXTENT_DELALLOC, cached_state); + ret = btrfs_test_range_bit(tree, delalloc_start, delalloc_end, + EXTENT_DELALLOC, cached_state); + + btrfs_unlock_extent(tree, delalloc_start, delalloc_end, &cached_state); if (!ret) { - unlock_extent(tree, delalloc_start, delalloc_end, - &cached_state); - __unlock_for_delalloc(inode, locked_page, - delalloc_start, delalloc_end); + unlock_delalloc_folio(inode, locked_folio, delalloc_start, + delalloc_end); cond_resched(); goto again; } - free_extent_state(cached_state); *start = delalloc_start; *end = delalloc_end; out_failed: @@ -412,41 +393,43 @@ out_failed: } void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, - struct page *locked_page, + const struct folio *locked_folio, + struct extent_state **cached, u32 clear_bits, unsigned long page_ops) { - clear_extent_bit(&inode->io_tree, start, end, clear_bits, NULL); + btrfs_clear_extent_bit(&inode->io_tree, start, end, clear_bits, cached); - __process_pages_contig(inode->vfs_inode.i_mapping, locked_page, - start, end, page_ops); + __process_folios_contig(inode->vfs_inode.i_mapping, locked_folio, start, + end, page_ops); } -static bool btrfs_verify_page(struct page *page, u64 start) +static bool btrfs_verify_folio(struct folio *folio, u64 start, u32 len) { - if (!fsverity_active(page->mapping->host) || - PageUptodate(page) || - start >= i_size_read(page->mapping->host)) + struct btrfs_fs_info *fs_info = folio_to_fs_info(folio); + + if (!fsverity_active(folio->mapping->host) || + btrfs_folio_test_uptodate(fs_info, folio, start, len) || + start >= i_size_read(folio->mapping->host)) return true; - return fsverity_verify_page(page); + return fsverity_verify_folio(folio); } -static void end_page_read(struct page *page, bool uptodate, u64 start, u32 len) +static void end_folio_read(struct folio *folio, bool uptodate, u64 start, u32 len) { - struct btrfs_fs_info *fs_info = page_to_fs_info(page); - struct folio *folio = page_folio(page); + struct btrfs_fs_info *fs_info = folio_to_fs_info(folio); - ASSERT(page_offset(page) <= start && - start + len <= page_offset(page) + PAGE_SIZE); + ASSERT(folio_pos(folio) <= start && + start + len <= folio_pos(folio) + folio_size(folio)); - if (uptodate && btrfs_verify_page(page, start)) + if (uptodate && btrfs_verify_folio(folio, start, len)) btrfs_folio_set_uptodate(fs_info, folio, start, len); else btrfs_folio_clear_uptodate(fs_info, folio, start, len); - if (!btrfs_is_subpage(fs_info, page->mapping)) - unlock_page(page); + if (!btrfs_is_subpage(fs_info, folio)) + folio_unlock(folio); else - btrfs_subpage_end_reader(fs_info, folio, start, len); + btrfs_folio_end_lock(fs_info, folio, start, len); } /* @@ -473,9 +456,6 @@ static void end_bbio_data_write(struct btrfs_bio *bbio) u64 start = folio_pos(folio) + fi.offset; u32 len = fi.length; - /* Only order 0 (single page) folios are allowed for data. */ - ASSERT(folio_order(folio) == 0); - /* Our read/write should always be sector aligned. */ if (!IS_ALIGNED(fi.offset, sectorsize)) btrfs_err(fs_info, @@ -486,8 +466,8 @@ static void end_bbio_data_write(struct btrfs_bio *bbio) "incomplete page write with offset %zu and length %zu", fi.offset, fi.length); - btrfs_finish_ordered_extent(bbio->ordered, - folio_page(folio, 0), start, len, !error); + btrfs_finish_ordered_extent(bbio->ordered, folio, start, len, + !error); if (error) mapping_set_error(folio->mapping, error); btrfs_folio_clear_writeback(fs_info, folio, start, len); @@ -496,85 +476,14 @@ static void end_bbio_data_write(struct btrfs_bio *bbio) bio_put(bio); } -/* - * Record previously processed extent range - * - * For endio_readpage_release_extent() to handle a full extent range, reducing - * the extent io operations. - */ -struct processed_extent { - struct btrfs_inode *inode; - /* Start of the range in @inode */ - u64 start; - /* End of the range in @inode */ - u64 end; - bool uptodate; -}; - -/* - * Try to release processed extent range - * - * May not release the extent range right now if the current range is - * contiguous to processed extent. - * - * Will release processed extent when any of @inode, @uptodate, the range is - * no longer contiguous to the processed range. - * - * Passing @inode == NULL will force processed extent to be released. - */ -static void endio_readpage_release_extent(struct processed_extent *processed, - struct btrfs_inode *inode, u64 start, u64 end, - bool uptodate) -{ - struct extent_state *cached = NULL; - struct extent_io_tree *tree; - - /* The first extent, initialize @processed */ - if (!processed->inode) - goto update; - - /* - * Contiguous to processed extent, just uptodate the end. - * - * Several things to notice: - * - * - bio can be merged as long as on-disk bytenr is contiguous - * This means we can have page belonging to other inodes, thus need to - * check if the inode still matches. - * - bvec can contain range beyond current page for multi-page bvec - * Thus we need to do processed->end + 1 >= start check - */ - if (processed->inode == inode && processed->uptodate == uptodate && - processed->end + 1 >= start && end >= processed->end) { - processed->end = end; - return; - } - - tree = &processed->inode->io_tree; - /* - * Now we don't have range contiguous to the processed range, release - * the processed range now. - */ - unlock_extent(tree, processed->start, processed->end, &cached); - -update: - /* Update processed to current range */ - processed->inode = inode; - processed->start = start; - processed->end = end; - processed->uptodate = uptodate; -} - -static void begin_page_read(struct btrfs_fs_info *fs_info, struct page *page) +static void begin_folio_read(struct btrfs_fs_info *fs_info, struct folio *folio) { - struct folio *folio = page_folio(page); - ASSERT(folio_test_locked(folio)); - if (!btrfs_is_subpage(fs_info, folio->mapping)) + if (!btrfs_is_subpage(fs_info, folio)) return; ASSERT(folio_test_private(folio)); - btrfs_subpage_start_reader(fs_info, folio, page_offset(page), PAGE_SIZE); + btrfs_folio_set_lock(fs_info, folio, folio_pos(folio), folio_size(folio)); } /* @@ -593,49 +502,24 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) { struct btrfs_fs_info *fs_info = bbio->fs_info; struct bio *bio = &bbio->bio; - struct processed_extent processed = { 0 }; struct folio_iter fi; - const u32 sectorsize = fs_info->sectorsize; ASSERT(!bio_flagged(bio, BIO_CLONED)); bio_for_each_folio_all(fi, &bbio->bio) { bool uptodate = !bio->bi_status; struct folio *folio = fi.folio; struct inode *inode = folio->mapping->host; - u64 start; - u64 end; - u32 len; + u64 start = folio_pos(folio) + fi.offset; - /* For now only order 0 folios are supported for data. */ - ASSERT(folio_order(folio) == 0); btrfs_debug(fs_info, "%s: bi_sector=%llu, err=%d, mirror=%u", __func__, bio->bi_iter.bi_sector, bio->bi_status, bbio->mirror_num); - /* - * We always issue full-sector reads, but if some block in a - * folio fails to read, blk_update_request() will advance - * bv_offset and adjust bv_len to compensate. Print a warning - * for unaligned offsets, and an error if they don't add up to - * a full sector. - */ - if (!IS_ALIGNED(fi.offset, sectorsize)) - btrfs_err(fs_info, - "partial page read in btrfs with offset %zu and length %zu", - fi.offset, fi.length); - else if (!IS_ALIGNED(fi.offset + fi.length, sectorsize)) - btrfs_info(fs_info, - "incomplete page read with offset %zu and length %zu", - fi.offset, fi.length); - - start = folio_pos(folio) + fi.offset; - end = start + fi.length - 1; - len = fi.length; if (likely(uptodate)) { + u64 end = start + fi.length - 1; loff_t i_size = i_size_read(inode); - pgoff_t end_index = i_size >> folio_shift(folio); /* * Zero out the remaining part if this range straddles @@ -644,9 +528,11 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) * Here we should only zero the range inside the folio, * not touch anything else. * - * NOTE: i_size is exclusive while end is inclusive. + * NOTE: i_size is exclusive while end is inclusive and + * folio_contains() takes PAGE_SIZE units. */ - if (folio_index(folio) == end_index && i_size <= end) { + if (folio_contains(folio, i_size >> PAGE_SHIFT) && + i_size <= end) { u32 zero_start = max(offset_in_folio(folio, i_size), offset_in_folio(folio, start)); u32 zero_len = offset_in_folio(folio, end) + 1 - @@ -657,55 +543,70 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) } /* Update page status and unlock. */ - end_page_read(folio_page(folio, 0), uptodate, start, len); - endio_readpage_release_extent(&processed, BTRFS_I(inode), - start, end, uptodate); + end_folio_read(folio, uptodate, start, fi.length); } - /* Release the last extent */ - endio_readpage_release_extent(&processed, NULL, 0, 0, false); bio_put(bio); } /* - * Populate every free slot in a provided array with pages. + * Populate every free slot in a provided array with folios using GFP_NOFS. + * + * @nr_folios: number of folios to allocate + * @folio_array: the array to fill with folios; any existing non-NULL entries in + * the array will be skipped + * + * Return: 0 if all folios were able to be allocated; + * -ENOMEM otherwise, the partially allocated folios would be freed and + * the array slots zeroed + */ +int btrfs_alloc_folio_array(unsigned int nr_folios, struct folio **folio_array) +{ + for (int i = 0; i < nr_folios; i++) { + if (folio_array[i]) + continue; + folio_array[i] = folio_alloc(GFP_NOFS, 0); + if (!folio_array[i]) + goto error; + } + return 0; +error: + for (int i = 0; i < nr_folios; i++) { + if (folio_array[i]) + folio_put(folio_array[i]); + } + return -ENOMEM; +} + +/* + * Populate every free slot in a provided array with pages, using GFP_NOFS. * * @nr_pages: number of pages to allocate * @page_array: the array to fill with pages; any existing non-null entries in - * the array will be skipped - * @extra_gfp: the extra GFP flags for the allocation. + * the array will be skipped + * @nofail: whether using __GFP_NOFAIL flag * * Return: 0 if all pages were able to be allocated; * -ENOMEM otherwise, the partially allocated pages would be freed and * the array slots zeroed */ int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array, - gfp_t extra_gfp) + bool nofail) { + const gfp_t gfp = nofail ? (GFP_NOFS | __GFP_NOFAIL) : GFP_NOFS; unsigned int allocated; for (allocated = 0; allocated < nr_pages;) { unsigned int last = allocated; - allocated = alloc_pages_bulk_array(GFP_NOFS | extra_gfp, - nr_pages, page_array); - - if (allocated == nr_pages) - return 0; - - /* - * During this iteration, no page could be allocated, even - * though alloc_pages_bulk_array() falls back to alloc_page() - * if it could not bulk-allocate. So we must be out of memory. - */ - if (allocated == last) { + allocated = alloc_pages_bulk(gfp, nr_pages, page_array); + if (unlikely(allocated == last)) { + /* No progress, fail and do cleanup. */ for (int i = 0; i < allocated; i++) { __free_page(page_array[i]); page_array[i] = NULL; } return -ENOMEM; } - - memalloc_retry_wait(GFP_NOFS); } return 0; } @@ -715,13 +616,13 @@ int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array, * * For now, the folios populated are always in order 0 (aka, single page). */ -static int alloc_eb_folio_array(struct extent_buffer *eb, gfp_t extra_gfp) +static int alloc_eb_folio_array(struct extent_buffer *eb, bool nofail) { struct page *page_array[INLINE_EXTENT_BUFFER_PAGES] = { 0 }; int num_pages = num_extent_pages(eb); int ret; - ret = btrfs_alloc_page_array(num_pages, page_array, extra_gfp); + ret = btrfs_alloc_page_array(num_pages, page_array, nofail); if (ret < 0) return ret; @@ -733,11 +634,9 @@ static int alloc_eb_folio_array(struct extent_buffer *eb, gfp_t extra_gfp) } static bool btrfs_bio_is_contig(struct btrfs_bio_ctrl *bio_ctrl, - struct page *page, u64 disk_bytenr, - unsigned int pg_offset) + u64 disk_bytenr, loff_t file_offset) { struct bio *bio = &bio_ctrl->bbio->bio; - struct bio_vec *bvec = bio_last_bvec_all(bio); const sector_t sector = disk_bytenr >> SECTOR_SHIFT; if (bio_ctrl->compress_type != BTRFS_COMPRESS_NONE) { @@ -749,19 +648,11 @@ static bool btrfs_bio_is_contig(struct btrfs_bio_ctrl *bio_ctrl, } /* - * The contig check requires the following conditions to be met: - * - * 1) The pages are belonging to the same inode - * This is implied by the call chain. - * - * 2) The range has adjacent logical bytenr - * - * 3) The range has adjacent file offset - * This is required for the usage of btrfs_bio->file_offset. + * To merge into a bio both the disk sector and the logical offset in + * the file need to be contiguous. */ - return bio_end_sector(bio) == sector && - page_offset(bvec->bv_page) + bvec->bv_offset + bvec->bv_len == - page_offset(page) + pg_offset; + return bio_ctrl->next_file_offset == file_offset && + bio_end_sector(bio) == sector; } static void alloc_new_bio(struct btrfs_inode *inode, @@ -774,10 +665,12 @@ static void alloc_new_bio(struct btrfs_inode *inode, bbio = btrfs_bio_alloc(BIO_MAX_VECS, bio_ctrl->opf, fs_info, bio_ctrl->end_io_func, NULL); bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT; + bbio->bio.bi_write_hint = inode->vfs_inode.i_write_hint; bbio->inode = inode; bbio->file_offset = file_offset; bio_ctrl->bbio = bbio; bio_ctrl->len_to_oe_boundary = U32_MAX; + bio_ctrl->next_file_offset = file_offset; /* Limit data write bios to the ordered boundary. */ if (bio_ctrl->wbc) { @@ -814,50 +707,51 @@ static void alloc_new_bio(struct btrfs_inode *inode, * The mirror number for this IO should already be initizlied in * @bio_ctrl->mirror_num. */ -static void submit_extent_page(struct btrfs_bio_ctrl *bio_ctrl, - u64 disk_bytenr, struct page *page, +static void submit_extent_folio(struct btrfs_bio_ctrl *bio_ctrl, + u64 disk_bytenr, struct folio *folio, size_t size, unsigned long pg_offset) { - struct btrfs_inode *inode = page_to_inode(page); + struct btrfs_inode *inode = folio_to_inode(folio); + loff_t file_offset = folio_pos(folio) + pg_offset; - ASSERT(pg_offset + size <= PAGE_SIZE); + ASSERT(pg_offset + size <= folio_size(folio)); ASSERT(bio_ctrl->end_io_func); if (bio_ctrl->bbio && - !btrfs_bio_is_contig(bio_ctrl, page, disk_bytenr, pg_offset)) + !btrfs_bio_is_contig(bio_ctrl, disk_bytenr, file_offset)) submit_one_bio(bio_ctrl); do { u32 len = size; /* Allocate new bio if needed */ - if (!bio_ctrl->bbio) { - alloc_new_bio(inode, bio_ctrl, disk_bytenr, - page_offset(page) + pg_offset); - } + if (!bio_ctrl->bbio) + alloc_new_bio(inode, bio_ctrl, disk_bytenr, file_offset); /* Cap to the current ordered extent boundary if there is one. */ if (len > bio_ctrl->len_to_oe_boundary) { ASSERT(bio_ctrl->compress_type == BTRFS_COMPRESS_NONE); - ASSERT(is_data_inode(&inode->vfs_inode)); + ASSERT(is_data_inode(inode)); len = bio_ctrl->len_to_oe_boundary; } - if (bio_add_page(&bio_ctrl->bbio->bio, page, len, pg_offset) != len) { + if (!bio_add_folio(&bio_ctrl->bbio->bio, folio, len, pg_offset)) { /* bio full: move on to a new one */ submit_one_bio(bio_ctrl); continue; } + bio_ctrl->next_file_offset += len; if (bio_ctrl->wbc) - wbc_account_cgroup_owner(bio_ctrl->wbc, page, len); + wbc_account_cgroup_owner(bio_ctrl->wbc, folio, len); size -= len; pg_offset += len; disk_bytenr += len; + file_offset += len; /* - * len_to_oe_boundary defaults to U32_MAX, which isn't page or + * len_to_oe_boundary defaults to U32_MAX, which isn't folio or * sector aligned. alloc_new_bio() then sets it to the end of * our ordered extent for writes into zoned devices. * @@ -867,15 +761,15 @@ static void submit_extent_page(struct btrfs_bio_ctrl *bio_ctrl, * boundary is correct. * * When len_to_oe_boundary is U32_MAX, the cap above would - * result in a 4095 byte IO for the last page right before - * we hit the bio limit of UINT_MAX. bio_add_page() has all + * result in a 4095 byte IO for the last folio right before + * we hit the bio limit of UINT_MAX. bio_add_folio() has all * the checks required to make sure we don't overflow the bio, * and we should just ignore len_to_oe_boundary completely * unless we're using it to track an ordered extent. * * It's pretty hard to make a bio sized U32_MAX, but it can * happen when the page cache is able to feed us contiguous - * pages for large extents. + * folios for large extents. */ if (bio_ctrl->len_to_oe_boundary != U32_MAX) bio_ctrl->len_to_oe_boundary -= len; @@ -902,7 +796,7 @@ static int attach_extent_buffer_folio(struct extent_buffer *eb, if (folio->mapping) lockdep_assert_held(&folio->mapping->i_private_lock); - if (fs_info->nodesize >= PAGE_SIZE) { + if (!btrfs_meta_is_subpage(fs_info)) { if (!folio_test_private(folio)) folio_attach_private(folio, eb); else @@ -925,11 +819,6 @@ static int attach_extent_buffer_folio(struct extent_buffer *eb, return ret; } -int set_page_extent_mapped(struct page *page) -{ - return set_folio_extent_mapped(page_folio(page)); -} - int set_folio_extent_mapped(struct folio *folio) { struct btrfs_fs_info *fs_info; @@ -941,32 +830,32 @@ int set_folio_extent_mapped(struct folio *folio) fs_info = folio_to_fs_info(folio); - if (btrfs_is_subpage(fs_info, folio->mapping)) + if (btrfs_is_subpage(fs_info, folio)) return btrfs_attach_subpage(fs_info, folio, BTRFS_SUBPAGE_DATA); folio_attach_private(folio, (void *)EXTENT_FOLIO_PRIVATE); return 0; } -void clear_page_extent_mapped(struct page *page) +void clear_folio_extent_mapped(struct folio *folio) { - struct folio *folio = page_folio(page); struct btrfs_fs_info *fs_info; - ASSERT(page->mapping); + ASSERT(folio->mapping); if (!folio_test_private(folio)) return; - fs_info = page_to_fs_info(page); - if (btrfs_is_subpage(fs_info, page->mapping)) - return btrfs_detach_subpage(fs_info, folio); + fs_info = folio_to_fs_info(folio); + if (btrfs_is_subpage(fs_info, folio)) + return btrfs_detach_subpage(fs_info, folio, BTRFS_SUBPAGE_DATA); folio_detach_private(folio); } -static struct extent_map *__get_extent_map(struct inode *inode, struct page *page, - u64 start, u64 len, struct extent_map **em_cached) +static struct extent_map *get_extent_map(struct btrfs_inode *inode, + struct folio *folio, u64 start, + u64 len, struct extent_map **em_cached) { struct extent_map *em; @@ -974,22 +863,23 @@ static struct extent_map *__get_extent_map(struct inode *inode, struct page *pag if (*em_cached) { em = *em_cached; - if (extent_map_in_tree(em) && start >= em->start && - start < extent_map_end(em)) { + if (btrfs_extent_map_in_tree(em) && start >= em->start && + start < btrfs_extent_map_end(em)) { refcount_inc(&em->refs); return em; } - free_extent_map(em); + btrfs_free_extent_map(em); *em_cached = NULL; } - em = btrfs_get_extent(BTRFS_I(inode), page, start, len); + em = btrfs_get_extent(inode, folio, start, len); if (!IS_ERR(em)) { BUG_ON(*em_cached); refcount_inc(&em->refs); *em_cached = em; } + return em; } /* @@ -999,75 +889,71 @@ static struct extent_map *__get_extent_map(struct inode *inode, struct page *pag * XXX JDM: This needs looking at to ensure proper page locking * return 0 on success, otherwise return error */ -static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, +static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached, struct btrfs_bio_ctrl *bio_ctrl, u64 *prev_em_start) { - struct inode *inode = page->mapping->host; + struct inode *inode = folio->mapping->host; struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); - u64 start = page_offset(page); - const u64 end = start + PAGE_SIZE - 1; - u64 cur = start; + u64 start = folio_pos(folio); + const u64 end = start + folio_size(folio) - 1; u64 extent_offset; u64 last_byte = i_size_read(inode); - u64 block_start; struct extent_map *em; int ret = 0; - size_t pg_offset = 0; - size_t iosize; - size_t blocksize = fs_info->sectorsize; - struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; + const size_t blocksize = fs_info->sectorsize; - ret = set_page_extent_mapped(page); + ret = set_folio_extent_mapped(folio); if (ret < 0) { - unlock_extent(tree, start, end, NULL); - unlock_page(page); + folio_unlock(folio); return ret; } - if (page->index == last_byte >> PAGE_SHIFT) { - size_t zero_offset = offset_in_page(last_byte); + if (folio_contains(folio, last_byte >> PAGE_SHIFT)) { + size_t zero_offset = offset_in_folio(folio, last_byte); - if (zero_offset) { - iosize = PAGE_SIZE - zero_offset; - memzero_page(page, zero_offset, iosize); - } + if (zero_offset) + folio_zero_range(folio, zero_offset, + folio_size(folio) - zero_offset); } bio_ctrl->end_io_func = end_bbio_data_read; - begin_page_read(fs_info, page); - while (cur <= end) { + begin_folio_read(fs_info, folio); + for (u64 cur = start; cur <= end; cur += blocksize) { enum btrfs_compression_type compress_type = BTRFS_COMPRESS_NONE; + unsigned long pg_offset = offset_in_folio(folio, cur); bool force_bio_submit = false; u64 disk_bytenr; + u64 block_start; ASSERT(IS_ALIGNED(cur, fs_info->sectorsize)); if (cur >= last_byte) { - iosize = PAGE_SIZE - pg_offset; - memzero_page(page, pg_offset, iosize); - unlock_extent(tree, cur, cur + iosize - 1, NULL); - end_page_read(page, true, cur, iosize); + folio_zero_range(folio, pg_offset, end - cur + 1); + end_folio_read(folio, true, cur, end - cur + 1); break; } - em = __get_extent_map(inode, page, cur, end - cur + 1, em_cached); + if (btrfs_folio_test_uptodate(fs_info, folio, cur, blocksize)) { + end_folio_read(folio, true, cur, blocksize); + continue; + } + em = get_extent_map(BTRFS_I(inode), folio, cur, end - cur + 1, em_cached); if (IS_ERR(em)) { - unlock_extent(tree, cur, end, NULL); - end_page_read(page, false, cur, end + 1 - cur); + end_folio_read(folio, false, cur, end + 1 - cur); return PTR_ERR(em); } extent_offset = cur - em->start; - BUG_ON(extent_map_end(em) <= cur); + BUG_ON(btrfs_extent_map_end(em) <= cur); BUG_ON(end < cur); - compress_type = extent_map_compression(em); + compress_type = btrfs_extent_map_compression(em); - iosize = min(extent_map_end(em) - cur, end - cur + 1); - iosize = ALIGN(iosize, blocksize); if (compress_type != BTRFS_COMPRESS_NONE) - disk_bytenr = em->block_start; + disk_bytenr = em->disk_bytenr; else - disk_bytenr = em->block_start + extent_offset; - block_start = em->block_start; + disk_bytenr = btrfs_extent_map_block_start(em) + extent_offset; + if (em->flags & EXTENT_FLAG_PREALLOC) block_start = EXTENT_MAP_HOLE; + else + block_start = btrfs_extent_map_block_start(em); /* * If we have a file range that points to a compressed extent @@ -1075,8 +961,8 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, * to the same compressed extent (possibly with a different * offset and/or length, so it either points to the whole extent * or only part of it), we must make sure we do not submit a - * single bio to populate the pages for the 2 ranges because - * this makes the compressed extent read zero out the pages + * single bio to populate the folios for the 2 ranges because + * this makes the compressed extent read zero out the folios * belonging to the 2nd range. Imagine the following scenario: * * File layout @@ -1089,13 +975,13 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, * [extent X, compressed length = 4K uncompressed length = 16K] * * If the bio to read the compressed extent covers both ranges, - * it will decompress extent X into the pages belonging to the + * it will decompress extent X into the folios belonging to the * first range and then it will stop, zeroing out the remaining - * pages that belong to the other range that points to extent X. + * folios that belong to the other range that points to extent X. * So here we make sure we submit 2 bios, one for the first * range and another one for the third range. Both will target * the same physical extent from disk, but we can't currently - * make the compressed bio endio callback populate the pages + * make the compressed bio endio callback populate the folios * for both ranges because each compressed bio is tightly * coupled with a single extent map, and each range can have * an extent map with a different offset value relative to the @@ -1111,25 +997,18 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, if (prev_em_start) *prev_em_start = em->start; - free_extent_map(em); + btrfs_free_extent_map(em); em = NULL; /* we've found a hole, just zero and go on */ if (block_start == EXTENT_MAP_HOLE) { - memzero_page(page, pg_offset, iosize); - - unlock_extent(tree, cur, cur + iosize - 1, NULL); - end_page_read(page, true, cur, iosize); - cur = cur + iosize; - pg_offset += iosize; + folio_zero_range(folio, pg_offset, blocksize); + end_folio_read(folio, true, cur, blocksize); continue; } - /* the get_extent function already copied into the page */ + /* the get_extent function already copied into the folio */ if (block_start == EXTENT_MAP_INLINE) { - unlock_extent(tree, cur, cur + iosize - 1, NULL); - end_page_read(page, true, cur, iosize); - cur = cur + iosize; - pg_offset += iosize; + end_folio_read(folio, true, cur, blocksize); continue; } @@ -1140,29 +1019,205 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, if (force_bio_submit) submit_one_bio(bio_ctrl); - submit_extent_page(bio_ctrl, disk_bytenr, page, iosize, - pg_offset); - cur = cur + iosize; - pg_offset += iosize; + submit_extent_folio(bio_ctrl, disk_bytenr, folio, blocksize, + pg_offset); } - return 0; } +/* + * Check if we can skip waiting the @ordered extent covering the block at @fileoff. + * + * @fileoff: Both input and output. + * Input as the file offset where the check should start at. + * Output as where the next check should start at, + * if the function returns true. + * + * Return true if we can skip to @fileoff. The caller needs to check the new + * @fileoff value to make sure it covers the full range, before skipping the + * full OE. + * + * Return false if we must wait for the ordered extent. + */ +static bool can_skip_one_ordered_range(struct btrfs_inode *inode, + struct btrfs_ordered_extent *ordered, + u64 *fileoff) +{ + const struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct folio *folio; + const u32 blocksize = fs_info->sectorsize; + u64 cur = *fileoff; + bool ret; + + folio = filemap_get_folio(inode->vfs_inode.i_mapping, cur >> PAGE_SHIFT); + + /* + * We should have locked the folio(s) for range [start, end], thus + * there must be a folio and it must be locked. + */ + ASSERT(!IS_ERR(folio)); + ASSERT(folio_test_locked(folio)); + + /* + * There are several cases for the folio and OE combination: + * + * 1) Folio has no private flag + * The OE has all its IO done but not yet finished, and folio got + * invalidated. + * + * Have we have to wait for the OE to finish, as it may contain the + * to-be-inserted data checksum. + * Without the data checksum inserted into the csum tree, read will + * just fail with missing csum. + */ + if (!folio_test_private(folio)) { + ret = false; + goto out; + } + + /* + * 2) The first block is DIRTY. + * + * This means the OE is created by some other folios whose file pos is + * before this one. And since we are holding the folio lock, the writeback + * of this folio cannot start. + * + * We must skip the whole OE, because it will never start until we + * finished our folio read and unlocked the folio. + */ + if (btrfs_folio_test_dirty(fs_info, folio, cur, blocksize)) { + u64 range_len = min(folio_pos(folio) + folio_size(folio), + ordered->file_offset + ordered->num_bytes) - cur; + + ret = true; + /* + * At least inside the folio, all the remaining blocks should + * also be dirty. + */ + ASSERT(btrfs_folio_test_dirty(fs_info, folio, cur, range_len)); + *fileoff = ordered->file_offset + ordered->num_bytes; + goto out; + } + + /* + * 3) The first block is uptodate. + * + * At least the first block can be skipped, but we are still not fully + * sure. E.g. if the OE has some other folios in the range that cannot + * be skipped. + * So we return true and update @next_ret to the OE/folio boundary. + */ + if (btrfs_folio_test_uptodate(fs_info, folio, cur, blocksize)) { + u64 range_len = min(folio_pos(folio) + folio_size(folio), + ordered->file_offset + ordered->num_bytes) - cur; + + /* + * The whole range to the OE end or folio boundary should also + * be uptodate. + */ + ASSERT(btrfs_folio_test_uptodate(fs_info, folio, cur, range_len)); + ret = true; + *fileoff = cur + range_len; + goto out; + } + + /* + * 4) The first block is not uptodate. + * + * This means the folio is invalidated after the writeback was finished, + * but by some other operations (e.g. block aligned buffered write) the + * folio is inserted into filemap. + * Very much the same as case 1). + */ + ret = false; +out: + folio_put(folio); + return ret; +} + +static bool can_skip_ordered_extent(struct btrfs_inode *inode, + struct btrfs_ordered_extent *ordered, + u64 start, u64 end) +{ + const u64 range_end = min(end, ordered->file_offset + ordered->num_bytes - 1); + u64 cur = max(start, ordered->file_offset); + + while (cur < range_end) { + bool can_skip; + + can_skip = can_skip_one_ordered_range(inode, ordered, &cur); + if (!can_skip) + return false; + } + return true; +} + +/* + * Locking helper to make sure we get a stable view of extent maps for the + * involved range. + * + * This is for folio read paths (read and readahead), thus the involved range + * should have all the folios locked. + */ +static void lock_extents_for_read(struct btrfs_inode *inode, u64 start, u64 end, + struct extent_state **cached_state) +{ + u64 cur_pos; + + /* Caller must provide a valid @cached_state. */ + ASSERT(cached_state); + + /* The range must at least be page aligned, as all read paths are folio based. */ + ASSERT(IS_ALIGNED(start, PAGE_SIZE)); + ASSERT(IS_ALIGNED(end + 1, PAGE_SIZE)); + +again: + btrfs_lock_extent(&inode->io_tree, start, end, cached_state); + cur_pos = start; + while (cur_pos < end) { + struct btrfs_ordered_extent *ordered; + + ordered = btrfs_lookup_ordered_range(inode, cur_pos, + end - cur_pos + 1); + /* + * No ordered extents in the range, and we hold the extent lock, + * no one can modify the extent maps in the range, we're safe to return. + */ + if (!ordered) + break; + + /* Check if we can skip waiting for the whole OE. */ + if (can_skip_ordered_extent(inode, ordered, start, end)) { + cur_pos = min(ordered->file_offset + ordered->num_bytes, + end + 1); + btrfs_put_ordered_extent(ordered); + continue; + } + + /* Now wait for the OE to finish. */ + btrfs_unlock_extent(&inode->io_tree, start, end, cached_state); + btrfs_start_ordered_extent_nowriteback(ordered, start, end + 1 - start); + btrfs_put_ordered_extent(ordered); + /* We have unlocked the whole range, restart from the beginning. */ + goto again; + } +} + int btrfs_read_folio(struct file *file, struct folio *folio) { - struct page *page = &folio->page; - struct btrfs_inode *inode = page_to_inode(page); - u64 start = page_offset(page); - u64 end = start + PAGE_SIZE - 1; + struct btrfs_inode *inode = folio_to_inode(folio); + const u64 start = folio_pos(folio); + const u64 end = start + folio_size(folio) - 1; + struct extent_state *cached_state = NULL; struct btrfs_bio_ctrl bio_ctrl = { .opf = REQ_OP_READ }; struct extent_map *em_cached = NULL; int ret; - btrfs_lock_and_flush_ordered_range(inode, start, end, NULL); + lock_extents_for_read(inode, start, end, &cached_state); + ret = btrfs_do_readpage(folio, &em_cached, &bio_ctrl, NULL); + btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state); - ret = btrfs_do_readpage(page, &em_cached, &bio_ctrl, NULL); - free_extent_map(em_cached); + btrfs_free_extent_map(em_cached); /* * If btrfs_do_readpage() failed we will want to submit the assembled @@ -1172,74 +1227,244 @@ int btrfs_read_folio(struct file *file, struct folio *folio) return ret; } -static inline void contiguous_readpages(struct page *pages[], int nr_pages, - u64 start, u64 end, - struct extent_map **em_cached, - struct btrfs_bio_ctrl *bio_ctrl, - u64 *prev_em_start) +static void set_delalloc_bitmap(struct folio *folio, unsigned long *delalloc_bitmap, + u64 start, u32 len) { - struct btrfs_inode *inode = page_to_inode(pages[0]); - int index; - - ASSERT(em_cached); + struct btrfs_fs_info *fs_info = folio_to_fs_info(folio); + const u64 folio_start = folio_pos(folio); + unsigned int start_bit; + unsigned int nbits; + + ASSERT(start >= folio_start && start + len <= folio_start + folio_size(folio)); + start_bit = (start - folio_start) >> fs_info->sectorsize_bits; + nbits = len >> fs_info->sectorsize_bits; + ASSERT(bitmap_test_range_all_zero(delalloc_bitmap, start_bit, nbits)); + bitmap_set(delalloc_bitmap, start_bit, nbits); +} - btrfs_lock_and_flush_ordered_range(inode, start, end, NULL); +static bool find_next_delalloc_bitmap(struct folio *folio, + unsigned long *delalloc_bitmap, u64 start, + u64 *found_start, u32 *found_len) +{ + struct btrfs_fs_info *fs_info = folio_to_fs_info(folio); + const u64 folio_start = folio_pos(folio); + const unsigned int bitmap_size = btrfs_blocks_per_folio(fs_info, folio); + unsigned int start_bit; + unsigned int first_zero; + unsigned int first_set; + + ASSERT(start >= folio_start && start < folio_start + folio_size(folio)); + + start_bit = (start - folio_start) >> fs_info->sectorsize_bits; + first_set = find_next_bit(delalloc_bitmap, bitmap_size, start_bit); + if (first_set >= bitmap_size) + return false; - for (index = 0; index < nr_pages; index++) { - btrfs_do_readpage(pages[index], em_cached, bio_ctrl, - prev_em_start); - put_page(pages[index]); - } + *found_start = folio_start + (first_set << fs_info->sectorsize_bits); + first_zero = find_next_zero_bit(delalloc_bitmap, bitmap_size, first_set); + *found_len = (first_zero - first_set) << fs_info->sectorsize_bits; + return true; } /* - * helper for __extent_writepage, doing all of the delayed allocation setup. + * Do all of the delayed allocation setup. * - * This returns 1 if btrfs_run_delalloc_range function did all the work required - * to write the page (copy into inline extent). In this case the IO has - * been started and the page is already unlocked. + * Return >0 if all the dirty blocks are submitted async (compression) or inlined. + * The @folio should no longer be touched (treat it as already unlocked). * - * This returns 0 if all went well (page still locked) - * This returns < 0 if there were errors (page still locked) + * Return 0 if there is still dirty block that needs to be submitted through + * extent_writepage_io(). + * bio_ctrl->submit_bitmap will indicate which blocks of the folio should be + * submitted, and @folio is still kept locked. + * + * Return <0 if there is any error hit. + * Any allocated ordered extent range covering this folio will be marked + * finished (IOERR), and @folio is still kept locked. */ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode, - struct page *page, struct writeback_control *wbc) + struct folio *folio, + struct btrfs_bio_ctrl *bio_ctrl) { - const u64 page_start = page_offset(page); - const u64 page_end = page_start + PAGE_SIZE - 1; + struct btrfs_fs_info *fs_info = inode_to_fs_info(&inode->vfs_inode); + struct writeback_control *wbc = bio_ctrl->wbc; + const bool is_subpage = btrfs_is_subpage(fs_info, folio); + const u64 page_start = folio_pos(folio); + const u64 page_end = page_start + folio_size(folio) - 1; + const unsigned int blocks_per_folio = btrfs_blocks_per_folio(fs_info, folio); + unsigned long delalloc_bitmap = 0; + /* + * Save the last found delalloc end. As the delalloc end can go beyond + * page boundary, thus we cannot rely on subpage bitmap to locate the + * last delalloc end. + */ + u64 last_delalloc_end = 0; + /* + * The range end (exclusive) of the last successfully finished delalloc + * range. + * Any range covered by ordered extent must either be manually marked + * finished (error handling), or has IO submitted (and finish the + * ordered extent normally). + * + * This records the end of ordered extent cleanup if we hit an error. + */ + u64 last_finished_delalloc_end = page_start; u64 delalloc_start = page_start; u64 delalloc_end = page_end; u64 delalloc_to_write = 0; int ret = 0; + int bit; + /* Save the dirty bitmap as our submission bitmap will be a subset of it. */ + if (btrfs_is_subpage(fs_info, folio)) { + ASSERT(blocks_per_folio > 1); + btrfs_get_subpage_dirty_bitmap(fs_info, folio, &bio_ctrl->submit_bitmap); + } else { + bio_ctrl->submit_bitmap = 1; + } + + for_each_set_bit(bit, &bio_ctrl->submit_bitmap, blocks_per_folio) { + u64 start = page_start + (bit << fs_info->sectorsize_bits); + + btrfs_folio_set_lock(fs_info, folio, start, fs_info->sectorsize); + } + + /* Lock all (subpage) delalloc ranges inside the folio first. */ while (delalloc_start < page_end) { delalloc_end = page_end; - if (!find_lock_delalloc_range(&inode->vfs_inode, page, + if (!find_lock_delalloc_range(&inode->vfs_inode, folio, &delalloc_start, &delalloc_end)) { delalloc_start = delalloc_end + 1; continue; } - - ret = btrfs_run_delalloc_range(inode, page, delalloc_start, - delalloc_end, wbc); - if (ret < 0) - return ret; - + set_delalloc_bitmap(folio, &delalloc_bitmap, delalloc_start, + min(delalloc_end, page_end) + 1 - delalloc_start); + last_delalloc_end = delalloc_end; delalloc_start = delalloc_end + 1; } + delalloc_start = page_start; + if (!last_delalloc_end) + goto out; + + /* Run the delalloc ranges for the above locked ranges. */ + while (delalloc_start < page_end) { + u64 found_start; + u32 found_len; + bool found; + + if (!is_subpage) { + /* + * For non-subpage case, the found delalloc range must + * cover this folio and there must be only one locked + * delalloc range. + */ + found_start = page_start; + found_len = last_delalloc_end + 1 - found_start; + found = true; + } else { + found = find_next_delalloc_bitmap(folio, &delalloc_bitmap, + delalloc_start, &found_start, &found_len); + } + if (!found) + break; + /* + * The subpage range covers the last sector, the delalloc range may + * end beyond the folio boundary, use the saved delalloc_end + * instead. + */ + if (found_start + found_len >= page_end) + found_len = last_delalloc_end + 1 - found_start; + + if (ret >= 0) { + /* + * Some delalloc range may be created by previous folios. + * Thus we still need to clean up this range during error + * handling. + */ + last_finished_delalloc_end = found_start; + /* No errors hit so far, run the current delalloc range. */ + ret = btrfs_run_delalloc_range(inode, folio, + found_start, + found_start + found_len - 1, + wbc); + if (ret >= 0) + last_finished_delalloc_end = found_start + found_len; + if (unlikely(ret < 0)) + btrfs_err_rl(fs_info, +"failed to run delalloc range, root=%lld ino=%llu folio=%llu submit_bitmap=%*pbl start=%llu len=%u: %d", + btrfs_root_id(inode->root), + btrfs_ino(inode), + folio_pos(folio), + blocks_per_folio, + &bio_ctrl->submit_bitmap, + found_start, found_len, ret); + } else { + /* + * We've hit an error during previous delalloc range, + * have to cleanup the remaining locked ranges. + */ + btrfs_unlock_extent(&inode->io_tree, found_start, + found_start + found_len - 1, NULL); + unlock_delalloc_folio(&inode->vfs_inode, folio, + found_start, + found_start + found_len - 1); + } + + /* + * We have some ranges that's going to be submitted asynchronously + * (compression or inline). These range have their own control + * on when to unlock the pages. We should not touch them + * anymore, so clear the range from the submission bitmap. + */ + if (ret > 0) { + unsigned int start_bit = (found_start - page_start) >> + fs_info->sectorsize_bits; + unsigned int end_bit = (min(page_end + 1, found_start + found_len) - + page_start) >> fs_info->sectorsize_bits; + bitmap_clear(&bio_ctrl->submit_bitmap, start_bit, end_bit - start_bit); + } + /* + * Above btrfs_run_delalloc_range() may have unlocked the folio, + * thus for the last range, we cannot touch the folio anymore. + */ + if (found_start + found_len >= last_delalloc_end + 1) + break; + + delalloc_start = found_start + found_len; + } + /* + * It's possible we had some ordered extents created before we hit + * an error, cleanup non-async successfully created delalloc ranges. + */ + if (unlikely(ret < 0)) { + unsigned int bitmap_size = min( + (last_finished_delalloc_end - page_start) >> + fs_info->sectorsize_bits, + blocks_per_folio); + + for_each_set_bit(bit, &bio_ctrl->submit_bitmap, bitmap_size) + btrfs_mark_ordered_io_finished(inode, folio, + page_start + (bit << fs_info->sectorsize_bits), + fs_info->sectorsize, false); + return ret; + } +out: + if (last_delalloc_end) + delalloc_end = last_delalloc_end; + else + delalloc_end = page_end; /* * delalloc_end is already one less than the total length, so - * we don't subtract one from PAGE_SIZE + * we don't subtract one from PAGE_SIZE. */ delalloc_to_write += DIV_ROUND_UP(delalloc_end + 1 - page_start, PAGE_SIZE); /* - * If btrfs_run_dealloc_range() already started I/O and unlocked - * the pages, we just need to account for them here. + * If all ranges are submitted asynchronously, we just need to account + * for them here. */ - if (ret == 1) { + if (bitmap_empty(&bio_ctrl->submit_bitmap, blocks_per_folio)) { wbc->nr_to_write -= delalloc_to_write; return 1; } @@ -1257,179 +1482,168 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode, } /* - * Find the first byte we need to write. + * Return 0 if we have submitted or queued the sector for submission. + * Return <0 for critical errors. * - * For subpage, one page can contain several sectors, and - * __extent_writepage_io() will just grab all extent maps in the page - * range and try to submit all non-inline/non-compressed extents. - * - * This is a big problem for subpage, we shouldn't re-submit already written - * data at all. - * This function will lookup subpage dirty bit to find which range we really - * need to submit. - * - * Return the next dirty range in [@start, @end). - * If no dirty range is found, @start will be page_offset(page) + PAGE_SIZE. + * Caller should make sure filepos < i_size and handle filepos >= i_size case. */ -static void find_next_dirty_byte(struct btrfs_fs_info *fs_info, - struct page *page, u64 *start, u64 *end) +static int submit_one_sector(struct btrfs_inode *inode, + struct folio *folio, + u64 filepos, struct btrfs_bio_ctrl *bio_ctrl, + loff_t i_size) { - struct folio *folio = page_folio(page); - struct btrfs_subpage *subpage = folio_get_private(folio); - struct btrfs_subpage_info *spi = fs_info->subpage_info; - u64 orig_start = *start; - /* Declare as unsigned long so we can use bitmap ops */ - unsigned long flags; - int range_start_bit; - int range_end_bit; + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct extent_map *em; + u64 block_start; + u64 disk_bytenr; + u64 extent_offset; + u64 em_end; + const u32 sectorsize = fs_info->sectorsize; - /* - * For regular sector size == page size case, since one page only - * contains one sector, we return the page offset directly. - */ - if (!btrfs_is_subpage(fs_info, page->mapping)) { - *start = page_offset(page); - *end = page_offset(page) + PAGE_SIZE; - return; - } + ASSERT(IS_ALIGNED(filepos, sectorsize)); + + /* @filepos >= i_size case should be handled by the caller. */ + ASSERT(filepos < i_size); + + em = btrfs_get_extent(inode, NULL, filepos, sectorsize); + if (IS_ERR(em)) + return PTR_ERR(em); + + extent_offset = filepos - em->start; + em_end = btrfs_extent_map_end(em); + ASSERT(filepos <= em_end); + ASSERT(IS_ALIGNED(em->start, sectorsize)); + ASSERT(IS_ALIGNED(em->len, sectorsize)); - range_start_bit = spi->dirty_offset + - (offset_in_page(orig_start) >> fs_info->sectorsize_bits); + block_start = btrfs_extent_map_block_start(em); + disk_bytenr = btrfs_extent_map_block_start(em) + extent_offset; - /* We should have the page locked, but just in case */ - spin_lock_irqsave(&subpage->lock, flags); - bitmap_next_set_region(subpage->bitmaps, &range_start_bit, &range_end_bit, - spi->dirty_offset + spi->bitmap_nr_bits); - spin_unlock_irqrestore(&subpage->lock, flags); + ASSERT(!btrfs_extent_map_is_compressed(em)); + ASSERT(block_start != EXTENT_MAP_HOLE); + ASSERT(block_start != EXTENT_MAP_INLINE); - range_start_bit -= spi->dirty_offset; - range_end_bit -= spi->dirty_offset; + btrfs_free_extent_map(em); + em = NULL; + + /* + * Although the PageDirty bit is cleared before entering this + * function, subpage dirty bit is not cleared. + * So clear subpage dirty bit here so next time we won't submit + * a folio for a range already written to disk. + */ + btrfs_folio_clear_dirty(fs_info, folio, filepos, sectorsize); + btrfs_folio_set_writeback(fs_info, folio, filepos, sectorsize); + /* + * Above call should set the whole folio with writeback flag, even + * just for a single subpage sector. + * As long as the folio is properly locked and the range is correct, + * we should always get the folio with writeback flag. + */ + ASSERT(folio_test_writeback(folio)); - *start = page_offset(page) + range_start_bit * fs_info->sectorsize; - *end = page_offset(page) + range_end_bit * fs_info->sectorsize; + submit_extent_folio(bio_ctrl, disk_bytenr, folio, + sectorsize, filepos - folio_pos(folio)); + return 0; } /* - * helper for __extent_writepage. This calls the writepage start hooks, + * Helper for extent_writepage(). This calls the writepage start hooks, * and does the loop to map the page into extents and bios. * * We return 1 if the IO is started and the page is unlocked, * 0 if all went well (page still locked) * < 0 if there were errors (page still locked) */ -static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode, - struct page *page, - struct btrfs_bio_ctrl *bio_ctrl, - loff_t i_size, - int *nr_ret) +static noinline_for_stack int extent_writepage_io(struct btrfs_inode *inode, + struct folio *folio, + u64 start, u32 len, + struct btrfs_bio_ctrl *bio_ctrl, + loff_t i_size) { struct btrfs_fs_info *fs_info = inode->root->fs_info; - u64 cur = page_offset(page); - u64 end = cur + PAGE_SIZE - 1; - u64 extent_offset; - u64 block_start; - struct extent_map *em; + unsigned long range_bitmap = 0; + bool submitted_io = false; + bool error = false; + const u64 folio_start = folio_pos(folio); + const unsigned int blocks_per_folio = btrfs_blocks_per_folio(fs_info, folio); + u64 cur; + int bit; int ret = 0; - int nr = 0; - ret = btrfs_writepage_cow_fixup(page); - if (ret) { + ASSERT(start >= folio_start && + start + len <= folio_start + folio_size(folio)); + + ret = btrfs_writepage_cow_fixup(folio); + if (ret == -EAGAIN) { /* Fixup worker will requeue */ - redirty_page_for_writepage(bio_ctrl->wbc, page); - unlock_page(page); + folio_redirty_for_writepage(bio_ctrl->wbc, folio); + folio_unlock(folio); return 1; } + if (ret < 0) + return ret; + + for (cur = start; cur < start + len; cur += fs_info->sectorsize) + set_bit((cur - folio_start) >> fs_info->sectorsize_bits, &range_bitmap); + bitmap_and(&bio_ctrl->submit_bitmap, &bio_ctrl->submit_bitmap, &range_bitmap, + blocks_per_folio); bio_ctrl->end_io_func = end_bbio_data_write; - while (cur <= end) { - u32 len = end - cur + 1; - u64 disk_bytenr; - u64 em_end; - u64 dirty_range_start = cur; - u64 dirty_range_end; - u32 iosize; + + for_each_set_bit(bit, &bio_ctrl->submit_bitmap, blocks_per_folio) { + cur = folio_pos(folio) + (bit << fs_info->sectorsize_bits); if (cur >= i_size) { - btrfs_mark_ordered_io_finished(inode, page, cur, len, - true); + btrfs_mark_ordered_io_finished(inode, folio, cur, + start + len - cur, true); /* * This range is beyond i_size, thus we don't need to * bother writing back. * But we still need to clear the dirty subpage bit, or - * the next time the page gets dirtied, we will try to + * the next time the folio gets dirtied, we will try to * writeback the sectors with subpage dirty bits, * causing writeback without ordered extent. */ - btrfs_folio_clear_dirty(fs_info, page_folio(page), cur, len); + btrfs_folio_clear_dirty(fs_info, folio, cur, + start + len - cur); break; } - - find_next_dirty_byte(fs_info, page, &dirty_range_start, - &dirty_range_end); - if (cur < dirty_range_start) { - cur = dirty_range_start; + ret = submit_one_sector(inode, folio, cur, bio_ctrl, i_size); + if (unlikely(ret < 0)) { + /* + * bio_ctrl may contain a bio crossing several folios. + * Submit it immediately so that the bio has a chance + * to finish normally, other than marked as error. + */ + submit_one_bio(bio_ctrl); + /* + * Failed to grab the extent map which should be very rare. + * Since there is no bio submitted to finish the ordered + * extent, we have to manually finish this sector. + */ + btrfs_mark_ordered_io_finished(inode, folio, cur, + fs_info->sectorsize, false); + error = true; continue; } - - em = btrfs_get_extent(inode, NULL, cur, len); - if (IS_ERR(em)) { - ret = PTR_ERR_OR_ZERO(em); - goto out_error; - } - - extent_offset = cur - em->start; - em_end = extent_map_end(em); - ASSERT(cur <= em_end); - ASSERT(cur < end); - ASSERT(IS_ALIGNED(em->start, fs_info->sectorsize)); - ASSERT(IS_ALIGNED(em->len, fs_info->sectorsize)); - - block_start = em->block_start; - disk_bytenr = em->block_start + extent_offset; - - ASSERT(!extent_map_is_compressed(em)); - ASSERT(block_start != EXTENT_MAP_HOLE); - ASSERT(block_start != EXTENT_MAP_INLINE); - - /* - * Note that em_end from extent_map_end() and dirty_range_end from - * find_next_dirty_byte() are all exclusive - */ - iosize = min(min(em_end, end + 1), dirty_range_end) - cur; - free_extent_map(em); - em = NULL; - - btrfs_set_range_writeback(inode, cur, cur + iosize - 1); - if (!PageWriteback(page)) { - btrfs_err(inode->root->fs_info, - "page %lu not writeback, cur %llu end %llu", - page->index, cur, end); - } - - /* - * Although the PageDirty bit is cleared before entering this - * function, subpage dirty bit is not cleared. - * So clear subpage dirty bit here so next time we won't submit - * page for range already written to disk. - */ - btrfs_folio_clear_dirty(fs_info, page_folio(page), cur, iosize); - - submit_extent_page(bio_ctrl, disk_bytenr, page, iosize, - cur - page_offset(page)); - cur += iosize; - nr++; + submitted_io = true; } - btrfs_folio_assert_not_dirty(fs_info, page_folio(page)); - *nr_ret = nr; - return 0; - -out_error: /* - * If we finish without problem, we should not only clear page dirty, - * but also empty subpage dirty bits + * If we didn't submitted any sector (>= i_size), folio dirty get + * cleared but PAGECACHE_TAG_DIRTY is not cleared (only cleared + * by folio_start_writeback() if the folio is not dirty). + * + * Here we set writeback and clear for the range. If the full folio + * is no longer dirty then we clear the PAGECACHE_TAG_DIRTY tag. + * + * If we hit any error, the corresponding sector will still be dirty + * thus no need to clear PAGECACHE_TAG_DIRTY. */ - *nr_ret = nr; + if (!submitted_io && !error) { + btrfs_folio_set_writeback(fs_info, folio, start, len); + btrfs_folio_clear_writeback(fs_info, folio, start, len); + } return ret; } @@ -1442,70 +1656,95 @@ out_error: * Return 0 if everything goes well. * Return <0 for error. */ -static int __extent_writepage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl) +static int extent_writepage(struct folio *folio, struct btrfs_bio_ctrl *bio_ctrl) { - struct folio *folio = page_folio(page); - struct inode *inode = page->mapping->host; - const u64 page_start = page_offset(page); + struct btrfs_inode *inode = BTRFS_I(folio->mapping->host); + struct btrfs_fs_info *fs_info = inode->root->fs_info; int ret; - int nr = 0; size_t pg_offset; - loff_t i_size = i_size_read(inode); + loff_t i_size = i_size_read(&inode->vfs_inode); unsigned long end_index = i_size >> PAGE_SHIFT; + const unsigned int blocks_per_folio = btrfs_blocks_per_folio(fs_info, folio); - trace___extent_writepage(page, inode, bio_ctrl->wbc); + trace_extent_writepage(folio, &inode->vfs_inode, bio_ctrl->wbc); - WARN_ON(!PageLocked(page)); + WARN_ON(!folio_test_locked(folio)); - pg_offset = offset_in_page(i_size); - if (page->index > end_index || - (page->index == end_index && !pg_offset)) { + pg_offset = offset_in_folio(folio, i_size); + if (folio->index > end_index || + (folio->index == end_index && !pg_offset)) { folio_invalidate(folio, 0, folio_size(folio)); folio_unlock(folio); return 0; } - if (page->index == end_index) - memzero_page(page, pg_offset, PAGE_SIZE - pg_offset); + if (folio_contains(folio, end_index)) + folio_zero_range(folio, pg_offset, folio_size(folio) - pg_offset); - ret = set_page_extent_mapped(page); + /* + * Default to unlock the whole folio. + * The proper bitmap can only be initialized until writepage_delalloc(). + */ + bio_ctrl->submit_bitmap = (unsigned long)-1; + + /* + * If the page is dirty but without private set, it's marked dirty + * without informing the fs. + * Nowadays that is a bug, since the introduction of + * pin_user_pages*(). + * + * So here we check if the page has private set to rule out such + * case. + * But we also have a long history of relying on the COW fixup, + * so here we only enable this check for experimental builds until + * we're sure it's safe. + */ + if (IS_ENABLED(CONFIG_BTRFS_EXPERIMENTAL) && + unlikely(!folio_test_private(folio))) { + WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); + btrfs_err_rl(fs_info, + "root %lld ino %llu folio %llu is marked dirty without notifying the fs", + inode->root->root_key.objectid, + btrfs_ino(inode), folio_pos(folio)); + ret = -EUCLEAN; + goto done; + } + + ret = set_folio_extent_mapped(folio); if (ret < 0) goto done; - ret = writepage_delalloc(BTRFS_I(inode), page, bio_ctrl->wbc); + ret = writepage_delalloc(inode, folio, bio_ctrl); if (ret == 1) return 0; if (ret) goto done; - ret = __extent_writepage_io(BTRFS_I(inode), page, bio_ctrl, i_size, &nr); + ret = extent_writepage_io(inode, folio, folio_pos(folio), + folio_size(folio), bio_ctrl, i_size); if (ret == 1) return 0; + if (ret < 0) + btrfs_err_rl(fs_info, +"failed to submit blocks, root=%lld inode=%llu folio=%llu submit_bitmap=%*pbl: %d", + btrfs_root_id(inode->root), btrfs_ino(inode), + folio_pos(folio), blocks_per_folio, + &bio_ctrl->submit_bitmap, ret); bio_ctrl->wbc->nr_to_write--; done: - if (nr == 0) { - /* make sure the mapping tag for page dirty gets cleared */ - set_page_writeback(page); - end_page_writeback(page); - } - if (ret) { - btrfs_mark_ordered_io_finished(BTRFS_I(inode), page, page_start, - PAGE_SIZE, !ret); - mapping_set_error(page->mapping, ret); - } - unlock_page(page); + if (ret < 0) + mapping_set_error(folio->mapping, ret); + /* + * Only unlock ranges that are submitted. As there can be some async + * submitted ranges inside the folio. + */ + btrfs_folio_end_lock_bitmap(fs_info, folio, bio_ctrl->submit_bitmap); ASSERT(ret <= 0); return ret; } -void wait_on_extent_buffer_writeback(struct extent_buffer *eb) -{ - wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, - TASK_UNINTERRUPTIBLE); -} - /* * Lock extent buffer status and pages for writeback. * @@ -1535,8 +1774,18 @@ static noinline_for_stack bool lock_extent_buffer_for_io(struct extent_buffer *e */ spin_lock(&eb->refs_lock); if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { + XA_STATE(xas, &fs_info->buffer_tree, eb->start >> fs_info->sectorsize_bits); + unsigned long flags; + set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); spin_unlock(&eb->refs_lock); + + xas_lock_irqsave(&xas, flags); + xas_load(&xas); + xas_set_mark(&xas, PAGECACHE_TAG_WRITEBACK); + xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY); + xas_unlock_irqrestore(&xas, flags); + btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, -eb->len, @@ -1581,7 +1830,7 @@ static void set_btree_ioerr(struct extent_buffer *eb) * can be no longer dirty nor marked anymore for writeback (if a * subsequent modification to the extent buffer didn't happen before the * transaction commit), which makes filemap_fdata[write|wait]_range not - * able to find the pages tagged with SetPageError at transaction + * able to find the pages which contain errors at transaction * commit time. So if this happens we must abort the transaction, * otherwise we commit a super block with btree roots that point to * btree nodes/leafs whose content on disk is invalid - either garbage @@ -1622,6 +1871,135 @@ static void set_btree_ioerr(struct extent_buffer *eb) } } +static void buffer_tree_set_mark(const struct extent_buffer *eb, xa_mark_t mark) +{ + struct btrfs_fs_info *fs_info = eb->fs_info; + XA_STATE(xas, &fs_info->buffer_tree, eb->start >> fs_info->sectorsize_bits); + unsigned long flags; + + xas_lock_irqsave(&xas, flags); + xas_load(&xas); + xas_set_mark(&xas, mark); + xas_unlock_irqrestore(&xas, flags); +} + +static void buffer_tree_clear_mark(const struct extent_buffer *eb, xa_mark_t mark) +{ + struct btrfs_fs_info *fs_info = eb->fs_info; + XA_STATE(xas, &fs_info->buffer_tree, eb->start >> fs_info->sectorsize_bits); + unsigned long flags; + + xas_lock_irqsave(&xas, flags); + xas_load(&xas); + xas_clear_mark(&xas, mark); + xas_unlock_irqrestore(&xas, flags); +} + +static void buffer_tree_tag_for_writeback(struct btrfs_fs_info *fs_info, + unsigned long start, unsigned long end) +{ + XA_STATE(xas, &fs_info->buffer_tree, start); + unsigned int tagged = 0; + void *eb; + + xas_lock_irq(&xas); + xas_for_each_marked(&xas, eb, end, PAGECACHE_TAG_DIRTY) { + xas_set_mark(&xas, PAGECACHE_TAG_TOWRITE); + if (++tagged % XA_CHECK_SCHED) + continue; + xas_pause(&xas); + xas_unlock_irq(&xas); + cond_resched(); + xas_lock_irq(&xas); + } + xas_unlock_irq(&xas); +} + +struct eb_batch { + unsigned int nr; + unsigned int cur; + struct extent_buffer *ebs[PAGEVEC_SIZE]; +}; + +static inline bool eb_batch_add(struct eb_batch *batch, struct extent_buffer *eb) +{ + batch->ebs[batch->nr++] = eb; + return (batch->nr < PAGEVEC_SIZE); +} + +static inline void eb_batch_init(struct eb_batch *batch) +{ + batch->nr = 0; + batch->cur = 0; +} + +static inline struct extent_buffer *eb_batch_next(struct eb_batch *batch) +{ + if (batch->cur >= batch->nr) + return NULL; + return batch->ebs[batch->cur++]; +} + +static inline void eb_batch_release(struct eb_batch *batch) +{ + for (unsigned int i = 0; i < batch->nr; i++) + free_extent_buffer(batch->ebs[i]); + eb_batch_init(batch); +} + +static inline struct extent_buffer *find_get_eb(struct xa_state *xas, unsigned long max, + xa_mark_t mark) +{ + struct extent_buffer *eb; + +retry: + eb = xas_find_marked(xas, max, mark); + + if (xas_retry(xas, eb)) + goto retry; + + if (!eb) + return NULL; + + if (!atomic_inc_not_zero(&eb->refs)) { + xas_reset(xas); + goto retry; + } + + if (unlikely(eb != xas_reload(xas))) { + free_extent_buffer(eb); + xas_reset(xas); + goto retry; + } + + return eb; +} + +static unsigned int buffer_tree_get_ebs_tag(struct btrfs_fs_info *fs_info, + unsigned long *start, + unsigned long end, xa_mark_t tag, + struct eb_batch *batch) +{ + XA_STATE(xas, &fs_info->buffer_tree, *start); + struct extent_buffer *eb; + + rcu_read_lock(); + while ((eb = find_get_eb(&xas, end, tag)) != NULL) { + if (!eb_batch_add(batch, eb)) { + *start = ((eb->start + eb->len) >> fs_info->sectorsize_bits); + goto out; + } + } + if (end == ULONG_MAX) + *start = ULONG_MAX; + else + *start = end + 1; +out: + rcu_read_unlock(); + + return batch->nr; +} + /* * The endio specific version which won't touch any unsafe spinlock in endio * context. @@ -1630,38 +2008,29 @@ static struct extent_buffer *find_extent_buffer_nolock( struct btrfs_fs_info *fs_info, u64 start) { struct extent_buffer *eb; + unsigned long index = (start >> fs_info->sectorsize_bits); rcu_read_lock(); - eb = radix_tree_lookup(&fs_info->buffer_radix, - start >> fs_info->sectorsize_bits); - if (eb && atomic_inc_not_zero(&eb->refs)) { - rcu_read_unlock(); - return eb; - } + eb = xa_load(&fs_info->buffer_tree, index); + if (eb && !atomic_inc_not_zero(&eb->refs)) + eb = NULL; rcu_read_unlock(); - return NULL; + return eb; } static void end_bbio_meta_write(struct btrfs_bio *bbio) { struct extent_buffer *eb = bbio->private; - struct btrfs_fs_info *fs_info = eb->fs_info; - bool uptodate = !bbio->bio.bi_status; struct folio_iter fi; - u32 bio_offset = 0; - if (!uptodate) + if (bbio->bio.bi_status != BLK_STS_OK) set_btree_ioerr(eb); bio_for_each_folio_all(fi, &bbio->bio) { - u64 start = eb->start + bio_offset; - struct folio *folio = fi.folio; - u32 len = fi.length; - - btrfs_folio_clear_writeback(fs_info, folio, start, len); - bio_offset += len; + btrfs_meta_folio_clear_writeback(fi.folio, eb); } + buffer_tree_clear_mark(eb, PAGECACHE_TAG_WRITEBACK); clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); smp_mb__after_atomic(); wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK); @@ -1713,202 +2082,56 @@ static noinline_for_stack void write_one_eb(struct extent_buffer *eb, wbc_init_bio(wbc, &bbio->bio); bbio->inode = BTRFS_I(eb->fs_info->btree_inode); bbio->file_offset = eb->start; - if (fs_info->nodesize < PAGE_SIZE) { - struct folio *folio = eb->folios[0]; - bool ret; + for (int i = 0; i < num_extent_folios(eb); i++) { + struct folio *folio = eb->folios[i]; + u64 range_start = max_t(u64, eb->start, folio_pos(folio)); + u32 range_len = min_t(u64, folio_pos(folio) + folio_size(folio), + eb->start + eb->len) - range_start; folio_lock(folio); - btrfs_subpage_set_writeback(fs_info, folio, eb->start, eb->len); - if (btrfs_subpage_clear_and_test_dirty(fs_info, folio, eb->start, - eb->len)) { - folio_clear_dirty_for_io(folio); - wbc->nr_to_write--; - } - ret = bio_add_folio(&bbio->bio, folio, eb->len, - eb->start - folio_pos(folio)); - ASSERT(ret); - wbc_account_cgroup_owner(wbc, folio_page(folio, 0), eb->len); - folio_unlock(folio); - } else { - int num_folios = num_extent_folios(eb); - - for (int i = 0; i < num_folios; i++) { - struct folio *folio = eb->folios[i]; - bool ret; - - folio_lock(folio); - folio_clear_dirty_for_io(folio); - folio_start_writeback(folio); - ret = bio_add_folio(&bbio->bio, folio, eb->folio_size, 0); - ASSERT(ret); - wbc_account_cgroup_owner(wbc, folio_page(folio, 0), - eb->folio_size); + btrfs_meta_folio_clear_dirty(folio, eb); + btrfs_meta_folio_set_writeback(folio, eb); + if (!folio_test_dirty(folio)) wbc->nr_to_write -= folio_nr_pages(folio); - folio_unlock(folio); - } + bio_add_folio_nofail(&bbio->bio, folio, range_len, + offset_in_folio(folio, range_start)); + wbc_account_cgroup_owner(wbc, folio, range_len); + folio_unlock(folio); } - btrfs_submit_bio(bbio, 0); + btrfs_submit_bbio(bbio, 0); } /* - * Submit one subpage btree page. - * - * The main difference to submit_eb_page() is: - * - Page locking - * For subpage, we don't rely on page locking at all. - * - * - Flush write bio - * We only flush bio if we may be unable to fit current extent buffers into - * current bio. + * Wait for all eb writeback in the given range to finish. * - * Return >=0 for the number of submitted extent buffers. - * Return <0 for fatal error. + * @fs_info: The fs_info for this file system. + * @start: The offset of the range to start waiting on writeback. + * @end: The end of the range, inclusive. This is meant to be used in + * conjuction with wait_marked_extents, so this will usually be + * the_next_eb->start - 1. */ -static int submit_eb_subpage(struct page *page, struct writeback_control *wbc) +void btrfs_btree_wait_writeback_range(struct btrfs_fs_info *fs_info, u64 start, + u64 end) { - struct btrfs_fs_info *fs_info = page_to_fs_info(page); - struct folio *folio = page_folio(page); - int submitted = 0; - u64 page_start = page_offset(page); - int bit_start = 0; - int sectors_per_node = fs_info->nodesize >> fs_info->sectorsize_bits; - - /* Lock and write each dirty extent buffers in the range */ - while (bit_start < fs_info->subpage_info->bitmap_nr_bits) { - struct btrfs_subpage *subpage = folio_get_private(folio); + struct eb_batch batch; + unsigned long start_index = (start >> fs_info->sectorsize_bits); + unsigned long end_index = (end >> fs_info->sectorsize_bits); + + eb_batch_init(&batch); + while (start_index <= end_index) { struct extent_buffer *eb; - unsigned long flags; - u64 start; + unsigned int nr_ebs; - /* - * Take private lock to ensure the subpage won't be detached - * in the meantime. - */ - spin_lock(&page->mapping->i_private_lock); - if (!folio_test_private(folio)) { - spin_unlock(&page->mapping->i_private_lock); + nr_ebs = buffer_tree_get_ebs_tag(fs_info, &start_index, end_index, + PAGECACHE_TAG_WRITEBACK, &batch); + if (!nr_ebs) break; - } - spin_lock_irqsave(&subpage->lock, flags); - if (!test_bit(bit_start + fs_info->subpage_info->dirty_offset, - subpage->bitmaps)) { - spin_unlock_irqrestore(&subpage->lock, flags); - spin_unlock(&page->mapping->i_private_lock); - bit_start++; - continue; - } - - start = page_start + bit_start * fs_info->sectorsize; - bit_start += sectors_per_node; - - /* - * Here we just want to grab the eb without touching extra - * spin locks, so call find_extent_buffer_nolock(). - */ - eb = find_extent_buffer_nolock(fs_info, start); - spin_unlock_irqrestore(&subpage->lock, flags); - spin_unlock(&page->mapping->i_private_lock); - - /* - * The eb has already reached 0 refs thus find_extent_buffer() - * doesn't return it. We don't need to write back such eb - * anyway. - */ - if (!eb) - continue; - if (lock_extent_buffer_for_io(eb, wbc)) { - write_one_eb(eb, wbc); - submitted++; - } - free_extent_buffer(eb); - } - return submitted; -} - -/* - * Submit all page(s) of one extent buffer. - * - * @page: the page of one extent buffer - * @eb_context: to determine if we need to submit this page, if current page - * belongs to this eb, we don't need to submit - * - * The caller should pass each page in their bytenr order, and here we use - * @eb_context to determine if we have submitted pages of one extent buffer. - * - * If we have, we just skip until we hit a new page that doesn't belong to - * current @eb_context. - * - * If not, we submit all the page(s) of the extent buffer. - * - * Return >0 if we have submitted the extent buffer successfully. - * Return 0 if we don't need to submit the page, as it's already submitted by - * previous call. - * Return <0 for fatal error. - */ -static int submit_eb_page(struct page *page, struct btrfs_eb_write_context *ctx) -{ - struct writeback_control *wbc = ctx->wbc; - struct address_space *mapping = page->mapping; - struct folio *folio = page_folio(page); - struct extent_buffer *eb; - int ret; - - if (!folio_test_private(folio)) - return 0; - - if (page_to_fs_info(page)->nodesize < PAGE_SIZE) - return submit_eb_subpage(page, wbc); - - spin_lock(&mapping->i_private_lock); - if (!folio_test_private(folio)) { - spin_unlock(&mapping->i_private_lock); - return 0; - } - - eb = folio_get_private(folio); - - /* - * Shouldn't happen and normally this would be a BUG_ON but no point - * crashing the machine for something we can survive anyway. - */ - if (WARN_ON(!eb)) { - spin_unlock(&mapping->i_private_lock); - return 0; - } - - if (eb == ctx->eb) { - spin_unlock(&mapping->i_private_lock); - return 0; - } - ret = atomic_inc_not_zero(&eb->refs); - spin_unlock(&mapping->i_private_lock); - if (!ret) - return 0; - - ctx->eb = eb; - - ret = btrfs_check_meta_write_pointer(eb->fs_info, ctx); - if (ret) { - if (ret == -EBUSY) - ret = 0; - free_extent_buffer(eb); - return ret; - } - - if (!lock_extent_buffer_for_io(eb, wbc)) { - free_extent_buffer(eb); - return 0; - } - /* Implies write in zoned mode. */ - if (ctx->zoned_bg) { - /* Mark the last eb in the block group. */ - btrfs_schedule_zone_finish_bg(ctx->zoned_bg, eb); - ctx->zoned_bg->meta_write_pointer += eb->len; + while ((eb = eb_batch_next(&batch)) != NULL) + wait_on_extent_buffer_writeback(eb); + eb_batch_release(&batch); + cond_resched(); } - write_one_eb(eb, wbc); - free_extent_buffer(eb); - return 1; } int btree_write_cache_pages(struct address_space *mapping, @@ -1919,25 +2142,27 @@ int btree_write_cache_pages(struct address_space *mapping, int ret = 0; int done = 0; int nr_to_write_done = 0; - struct folio_batch fbatch; - unsigned int nr_folios; - pgoff_t index; - pgoff_t end; /* Inclusive */ + struct eb_batch batch; + unsigned int nr_ebs; + unsigned long index; + unsigned long end; int scanned = 0; xa_mark_t tag; - folio_batch_init(&fbatch); + eb_batch_init(&batch); if (wbc->range_cyclic) { - index = mapping->writeback_index; /* Start from prev offset */ + index = ((mapping->writeback_index << PAGE_SHIFT) >> fs_info->sectorsize_bits); end = -1; + /* * Start from the beginning does not need to cycle over the * range, mark it as scanned. */ scanned = (index == 0); } else { - index = wbc->range_start >> PAGE_SHIFT; - end = wbc->range_end >> PAGE_SHIFT; + index = (wbc->range_start >> fs_info->sectorsize_bits); + end = (wbc->range_end >> fs_info->sectorsize_bits); + scanned = 1; } if (wbc->sync_mode == WB_SYNC_ALL) @@ -1947,31 +2172,39 @@ int btree_write_cache_pages(struct address_space *mapping, btrfs_zoned_meta_io_lock(fs_info); retry: if (wbc->sync_mode == WB_SYNC_ALL) - tag_pages_for_writeback(mapping, index, end); + buffer_tree_tag_for_writeback(fs_info, index, end); while (!done && !nr_to_write_done && (index <= end) && - (nr_folios = filemap_get_folios_tag(mapping, &index, end, - tag, &fbatch))) { - unsigned i; + (nr_ebs = buffer_tree_get_ebs_tag(fs_info, &index, end, tag, &batch))) { + struct extent_buffer *eb; - for (i = 0; i < nr_folios; i++) { - struct folio *folio = fbatch.folios[i]; + while ((eb = eb_batch_next(&batch)) != NULL) { + ctx.eb = eb; - ret = submit_eb_page(&folio->page, &ctx); - if (ret == 0) + ret = btrfs_check_meta_write_pointer(eb->fs_info, &ctx); + if (ret) { + if (ret == -EBUSY) + ret = 0; + + if (ret) { + done = 1; + break; + } continue; - if (ret < 0) { - done = 1; - break; } - /* - * the filesystem may choose to bump up nr_to_write. - * We have to make sure to honor the new nr_to_write - * at any time - */ - nr_to_write_done = wbc->nr_to_write <= 0; + if (!lock_extent_buffer_for_io(eb, wbc)) + continue; + + /* Implies write in zoned mode. */ + if (ctx.zoned_bg) { + /* Mark the last eb in the block group. */ + btrfs_schedule_zone_finish_bg(ctx.zoned_bg, eb); + ctx.zoned_bg->meta_write_pointer += eb->len; + } + write_one_eb(eb, wbc); } - folio_batch_release(&fbatch); + nr_to_write_done = (wbc->nr_to_write <= 0); + eb_batch_release(&batch); cond_resched(); } if (!scanned && !done) { @@ -2010,7 +2243,7 @@ retry: * extent io tree. Thus we don't want to submit such wild eb * if the fs already has error. * - * We can get ret > 0 from submit_extent_page() indicating how many ebs + * We can get ret > 0 from submit_extent_folio() indicating how many ebs * were submitted. Reset it to 0 to avoid false alerts for the caller. */ if (ret > 0) @@ -2116,10 +2349,8 @@ retry: done_index = folio_next_index(folio); /* * At this point we hold neither the i_pages lock nor - * the page lock: the page may be truncated or - * invalidated (changing page->mapping to NULL), - * or even swizzled back from swapper_space to - * tmpfs file mapping + * the folio lock: the folio may be truncated or + * invalidated (changing folio->mapping to NULL). */ if (!folio_trylock(folio)) { submit_write_bio(bio_ctrl, 0); @@ -2137,7 +2368,27 @@ retry: continue; } - if (wbc->sync_mode != WB_SYNC_NONE) { + /* + * For subpage case, compression can lead to mixed + * writeback and dirty flags, e.g: + * 0 32K 64K 96K 128K + * | |//////||/////| |//| + * + * In above case, [32K, 96K) is asynchronously submitted + * for compression, and [124K, 128K) needs to be written back. + * + * If we didn't wait wrtiteback for page 64K, [128K, 128K) + * won't be submitted as the page still has writeback flag + * and will be skipped in the next check. + * + * This mixed writeback and dirty case is only possible for + * subpage case. + * + * TODO: Remove this check after migrating compression to + * regular submission. + */ + if (wbc->sync_mode != WB_SYNC_NONE || + btrfs_is_subpage(inode_to_fs_info(inode), folio)) { if (folio_test_writeback(folio)) submit_write_bio(bio_ctrl, 0); folio_wait_writeback(folio); @@ -2149,7 +2400,7 @@ retry: continue; } - ret = __extent_writepage(&folio->page, bio_ctrl); + ret = extent_writepage(folio, bio_ctrl); if (ret < 0) { done = 1; break; @@ -2196,7 +2447,7 @@ retry: * already been ran (aka, ordered extent inserted) and all pages are still * locked. */ -void extent_write_locked_range(struct inode *inode, struct page *locked_page, +void extent_write_locked_range(struct inode *inode, const struct folio *locked_folio, u64 start, u64 end, struct writeback_control *wbc, bool pages_dirty) { @@ -2218,46 +2469,57 @@ void extent_write_locked_range(struct inode *inode, struct page *locked_page, ASSERT(IS_ALIGNED(start, sectorsize) && IS_ALIGNED(end + 1, sectorsize)); while (cur <= end) { - u64 cur_end = min(round_down(cur, PAGE_SIZE) + PAGE_SIZE - 1, end); - u32 cur_len = cur_end + 1 - cur; - struct page *page; - int nr = 0; - - page = find_get_page(mapping, cur >> PAGE_SHIFT); - ASSERT(PageLocked(page)); - if (pages_dirty && page != locked_page) { - ASSERT(PageDirty(page)); - clear_page_dirty_for_io(page); + u64 cur_end; + u32 cur_len; + struct folio *folio; + + folio = filemap_get_folio(mapping, cur >> PAGE_SHIFT); + + /* + * This shouldn't happen, the pages are pinned and locked, this + * code is just in case, but shouldn't actually be run. + */ + if (IS_ERR(folio)) { + cur_end = min(round_down(cur, PAGE_SIZE) + PAGE_SIZE - 1, end); + cur_len = cur_end + 1 - cur; + btrfs_mark_ordered_io_finished(BTRFS_I(inode), NULL, + cur, cur_len, false); + mapping_set_error(mapping, PTR_ERR(folio)); + cur = cur_end; + continue; } - ret = __extent_writepage_io(BTRFS_I(inode), page, &bio_ctrl, - i_size, &nr); + cur_end = min_t(u64, folio_pos(folio) + folio_size(folio) - 1, end); + cur_len = cur_end + 1 - cur; + + ASSERT(folio_test_locked(folio)); + if (pages_dirty && folio != locked_folio) + ASSERT(folio_test_dirty(folio)); + + /* + * Set the submission bitmap to submit all sectors. + * extent_writepage_io() will do the truncation correctly. + */ + bio_ctrl.submit_bitmap = (unsigned long)-1; + ret = extent_writepage_io(BTRFS_I(inode), folio, cur, cur_len, + &bio_ctrl, i_size); if (ret == 1) goto next_page; - /* Make sure the mapping tag for page dirty gets cleared. */ - if (nr == 0) { - set_page_writeback(page); - end_page_writeback(page); - } - if (ret) { - btrfs_mark_ordered_io_finished(BTRFS_I(inode), page, - cur, cur_len, !ret); - mapping_set_error(page->mapping, ret); - } - btrfs_folio_unlock_writer(fs_info, page_folio(page), cur, cur_len); + if (ret) + mapping_set_error(mapping, ret); + btrfs_folio_end_lock(fs_info, folio, cur, cur_len); if (ret < 0) found_error = true; next_page: - put_page(page); + folio_put(folio); cur = cur_end + 1; } submit_write_bio(&bio_ctrl, found_error ? ret : 0); } -int extent_writepages(struct address_space *mapping, - struct writeback_control *wbc) +int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct inode *inode = mapping->host; int ret = 0; @@ -2277,24 +2539,26 @@ int extent_writepages(struct address_space *mapping, return ret; } -void extent_readahead(struct readahead_control *rac) +void btrfs_readahead(struct readahead_control *rac) { struct btrfs_bio_ctrl bio_ctrl = { .opf = REQ_OP_READ | REQ_RAHEAD }; - struct page *pagepool[16]; + struct folio *folio; + struct btrfs_inode *inode = BTRFS_I(rac->mapping->host); + const u64 start = readahead_pos(rac); + const u64 end = start + readahead_length(rac) - 1; + struct extent_state *cached_state = NULL; struct extent_map *em_cached = NULL; u64 prev_em_start = (u64)-1; - int nr; - while ((nr = readahead_page_batch(rac, pagepool))) { - u64 contig_start = readahead_pos(rac); - u64 contig_end = contig_start + readahead_batch_length(rac) - 1; + lock_extents_for_read(inode, start, end, &cached_state); - contiguous_readpages(pagepool, nr, contig_start, contig_end, - &em_cached, &bio_ctrl, &prev_em_start); - } + while ((folio = readahead_folio(rac)) != NULL) + btrfs_do_readpage(folio, &em_cached, &bio_ctrl, &prev_em_start); + + btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state); if (em_cached) - free_extent_map(em_cached); + btrfs_free_extent_map(em_cached); submit_one_bio(&bio_ctrl); } @@ -2318,7 +2582,7 @@ int extent_invalidate_folio(struct extent_io_tree *tree, if (start > end) return 0; - lock_extent(tree, start, end, &cached_state); + btrfs_lock_extent(tree, start, end, &cached_state); folio_wait_writeback(folio); /* @@ -2326,1001 +2590,137 @@ int extent_invalidate_folio(struct extent_io_tree *tree, * so here we only need to unlock the extent range to free any * existing extent state. */ - unlock_extent(tree, start, end, &cached_state); + btrfs_unlock_extent(tree, start, end, &cached_state); return 0; } /* - * a helper for release_folio, this tests for areas of the page that - * are locked or under IO and drops the related state bits if it is safe - * to drop the page. - */ -static int try_release_extent_state(struct extent_io_tree *tree, - struct page *page, gfp_t mask) -{ - u64 start = page_offset(page); - u64 end = start + PAGE_SIZE - 1; - int ret = 1; - - if (test_range_bit_exists(tree, start, end, EXTENT_LOCKED)) { - ret = 0; - } else { - u32 clear_bits = ~(EXTENT_LOCKED | EXTENT_NODATASUM | - EXTENT_DELALLOC_NEW | EXTENT_CTLBITS | - EXTENT_QGROUP_RESERVED); - - /* - * At this point we can safely clear everything except the - * locked bit, the nodatasum bit and the delalloc new bit. - * The delalloc new bit will be cleared by ordered extent - * completion. - */ - ret = __clear_extent_bit(tree, start, end, clear_bits, NULL, NULL); - - /* if clear_extent_bit failed for enomem reasons, - * we can't allow the release to continue. - */ - if (ret < 0) - ret = 0; - else - ret = 1; - } - return ret; -} - -/* - * a helper for release_folio. As long as there are no locked extents - * in the range corresponding to the page, both state records and extent - * map records are removed - */ -int try_release_extent_mapping(struct page *page, gfp_t mask) -{ - struct extent_map *em; - u64 start = page_offset(page); - u64 end = start + PAGE_SIZE - 1; - struct btrfs_inode *btrfs_inode = page_to_inode(page); - struct extent_io_tree *tree = &btrfs_inode->io_tree; - struct extent_map_tree *map = &btrfs_inode->extent_tree; - - if (gfpflags_allow_blocking(mask) && - page->mapping->host->i_size > SZ_16M) { - u64 len; - while (start <= end) { - struct btrfs_fs_info *fs_info; - u64 cur_gen; - - len = end - start + 1; - write_lock(&map->lock); - em = lookup_extent_mapping(map, start, len); - if (!em) { - write_unlock(&map->lock); - break; - } - if ((em->flags & EXTENT_FLAG_PINNED) || - em->start != start) { - write_unlock(&map->lock); - free_extent_map(em); - break; - } - if (test_range_bit_exists(tree, em->start, - extent_map_end(em) - 1, - EXTENT_LOCKED)) - goto next; - /* - * If it's not in the list of modified extents, used - * by a fast fsync, we can remove it. If it's being - * logged we can safely remove it since fsync took an - * extra reference on the em. - */ - if (list_empty(&em->list) || - (em->flags & EXTENT_FLAG_LOGGING)) - goto remove_em; - /* - * If it's in the list of modified extents, remove it - * only if its generation is older then the current one, - * in which case we don't need it for a fast fsync. - * Otherwise don't remove it, we could be racing with an - * ongoing fast fsync that could miss the new extent. - */ - fs_info = btrfs_inode->root->fs_info; - spin_lock(&fs_info->trans_lock); - cur_gen = fs_info->generation; - spin_unlock(&fs_info->trans_lock); - if (em->generation >= cur_gen) - goto next; -remove_em: - /* - * We only remove extent maps that are not in the list of - * modified extents or that are in the list but with a - * generation lower then the current generation, so there - * is no need to set the full fsync flag on the inode (it - * hurts the fsync performance for workloads with a data - * size that exceeds or is close to the system's memory). - */ - remove_extent_mapping(map, em); - /* once for the rb tree */ - free_extent_map(em); -next: - start = extent_map_end(em); - write_unlock(&map->lock); - - /* once for us */ - free_extent_map(em); - - cond_resched(); /* Allow large-extent preemption. */ - } - } - return try_release_extent_state(tree, page, mask); -} - -struct btrfs_fiemap_entry { - u64 offset; - u64 phys; - u64 len; - u32 flags; -}; - -/* - * Indicate the caller of emit_fiemap_extent() that it needs to unlock the file - * range from the inode's io tree, unlock the subvolume tree search path, flush - * the fiemap cache and relock the file range and research the subvolume tree. - * The value here is something negative that can't be confused with a valid - * errno value and different from 1 because that's also a return value from - * fiemap_fill_next_extent() and also it's often used to mean some btree search - * did not find a key, so make it some distinct negative value. - */ -#define BTRFS_FIEMAP_FLUSH_CACHE (-(MAX_ERRNO + 1)) - -/* - * Used to: - * - * - Cache the next entry to be emitted to the fiemap buffer, so that we can - * merge extents that are contiguous and can be grouped as a single one; - * - * - Store extents ready to be written to the fiemap buffer in an intermediary - * buffer. This intermediary buffer is to ensure that in case the fiemap - * buffer is memory mapped to the fiemap target file, we don't deadlock - * during btrfs_page_mkwrite(). This is because during fiemap we are locking - * an extent range in order to prevent races with delalloc flushing and - * ordered extent completion, which is needed in order to reliably detect - * delalloc in holes and prealloc extents. And this can lead to a deadlock - * if the fiemap buffer is memory mapped to the file we are running fiemap - * against (a silly, useless in practice scenario, but possible) because - * btrfs_page_mkwrite() will try to lock the same extent range. + * A helper for struct address_space_operations::release_folio, this tests for + * areas of the folio that are locked or under IO and drops the related state + * bits if it is safe to drop the folio. */ -struct fiemap_cache { - /* An array of ready fiemap entries. */ - struct btrfs_fiemap_entry *entries; - /* Number of entries in the entries array. */ - int entries_size; - /* Index of the next entry in the entries array to write to. */ - int entries_pos; - /* - * Once the entries array is full, this indicates what's the offset for - * the next file extent item we must search for in the inode's subvolume - * tree after unlocking the extent range in the inode's io tree and - * releasing the search path. - */ - u64 next_search_offset; - /* - * This matches struct fiemap_extent_info::fi_mapped_extents, we use it - * to count ourselves emitted extents and stop instead of relying on - * fiemap_fill_next_extent() because we buffer ready fiemap entries at - * the @entries array, and we want to stop as soon as we hit the max - * amount of extents to map, not just to save time but also to make the - * logic at extent_fiemap() simpler. - */ - unsigned int extents_mapped; - /* Fields for the cached extent (unsubmitted, not ready, extent). */ - u64 offset; - u64 phys; - u64 len; - u32 flags; - bool cached; -}; - -static int flush_fiemap_cache(struct fiemap_extent_info *fieinfo, - struct fiemap_cache *cache) -{ - for (int i = 0; i < cache->entries_pos; i++) { - struct btrfs_fiemap_entry *entry = &cache->entries[i]; - int ret; - - ret = fiemap_fill_next_extent(fieinfo, entry->offset, - entry->phys, entry->len, - entry->flags); - /* - * Ignore 1 (reached max entries) because we keep track of that - * ourselves in emit_fiemap_extent(). - */ - if (ret < 0) - return ret; - } - cache->entries_pos = 0; - - return 0; -} - -/* - * Helper to submit fiemap extent. - * - * Will try to merge current fiemap extent specified by @offset, @phys, - * @len and @flags with cached one. - * And only when we fails to merge, cached one will be submitted as - * fiemap extent. - * - * Return value is the same as fiemap_fill_next_extent(). - */ -static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo, - struct fiemap_cache *cache, - u64 offset, u64 phys, u64 len, u32 flags) -{ - struct btrfs_fiemap_entry *entry; - u64 cache_end; - - /* Set at the end of extent_fiemap(). */ - ASSERT((flags & FIEMAP_EXTENT_LAST) == 0); - - if (!cache->cached) - goto assign; - - /* - * When iterating the extents of the inode, at extent_fiemap(), we may - * find an extent that starts at an offset behind the end offset of the - * previous extent we processed. This happens if fiemap is called - * without FIEMAP_FLAG_SYNC and there are ordered extents completing - * after we had to unlock the file range, release the search path, emit - * the fiemap extents stored in the buffer (cache->entries array) and - * the lock the remainder of the range and re-search the btree. - * - * For example we are in leaf X processing its last item, which is the - * file extent item for file range [512K, 1M[, and after - * btrfs_next_leaf() releases the path, there's an ordered extent that - * completes for the file range [768K, 2M[, and that results in trimming - * the file extent item so that it now corresponds to the file range - * [512K, 768K[ and a new file extent item is inserted for the file - * range [768K, 2M[, which may end up as the last item of leaf X or as - * the first item of the next leaf - in either case btrfs_next_leaf() - * will leave us with a path pointing to the new extent item, for the - * file range [768K, 2M[, since that's the first key that follows the - * last one we processed. So in order not to report overlapping extents - * to user space, we trim the length of the previously cached extent and - * emit it. - * - * Upon calling btrfs_next_leaf() we may also find an extent with an - * offset smaller than or equals to cache->offset, and this happens - * when we had a hole or prealloc extent with several delalloc ranges in - * it, but after btrfs_next_leaf() released the path, delalloc was - * flushed and the resulting ordered extents were completed, so we can - * now have found a file extent item for an offset that is smaller than - * or equals to what we have in cache->offset. We deal with this as - * described below. - */ - cache_end = cache->offset + cache->len; - if (cache_end > offset) { - if (offset == cache->offset) { - /* - * We cached a dealloc range (found in the io tree) for - * a hole or prealloc extent and we have now found a - * file extent item for the same offset. What we have - * now is more recent and up to date, so discard what - * we had in the cache and use what we have just found. - */ - goto assign; - } else if (offset > cache->offset) { - /* - * The extent range we previously found ends after the - * offset of the file extent item we found and that - * offset falls somewhere in the middle of that previous - * extent range. So adjust the range we previously found - * to end at the offset of the file extent item we have - * just found, since this extent is more up to date. - * Emit that adjusted range and cache the file extent - * item we have just found. This corresponds to the case - * where a previously found file extent item was split - * due to an ordered extent completing. - */ - cache->len = offset - cache->offset; - goto emit; - } else { - const u64 range_end = offset + len; - - /* - * The offset of the file extent item we have just found - * is behind the cached offset. This means we were - * processing a hole or prealloc extent for which we - * have found delalloc ranges (in the io tree), so what - * we have in the cache is the last delalloc range we - * found while the file extent item we found can be - * either for a whole delalloc range we previously - * emmitted or only a part of that range. - * - * We have two cases here: - * - * 1) The file extent item's range ends at or behind the - * cached extent's end. In this case just ignore the - * current file extent item because we don't want to - * overlap with previous ranges that may have been - * emmitted already; - * - * 2) The file extent item starts behind the currently - * cached extent but its end offset goes beyond the - * end offset of the cached extent. We don't want to - * overlap with a previous range that may have been - * emmitted already, so we emit the currently cached - * extent and then partially store the current file - * extent item's range in the cache, for the subrange - * going the cached extent's end to the end of the - * file extent item. - */ - if (range_end <= cache_end) - return 0; - - if (!(flags & (FIEMAP_EXTENT_ENCODED | FIEMAP_EXTENT_DELALLOC))) - phys += cache_end - offset; - - offset = cache_end; - len = range_end - cache_end; - goto emit; - } - } - - /* - * Only merges fiemap extents if - * 1) Their logical addresses are continuous - * - * 2) Their physical addresses are continuous - * So truly compressed (physical size smaller than logical size) - * extents won't get merged with each other - * - * 3) Share same flags - */ - if (cache->offset + cache->len == offset && - cache->phys + cache->len == phys && - cache->flags == flags) { - cache->len += len; - return 0; - } - -emit: - /* Not mergeable, need to submit cached one */ - - if (cache->entries_pos == cache->entries_size) { - /* - * We will need to research for the end offset of the last - * stored extent and not from the current offset, because after - * unlocking the range and releasing the path, if there's a hole - * between that end offset and this current offset, a new extent - * may have been inserted due to a new write, so we don't want - * to miss it. - */ - entry = &cache->entries[cache->entries_size - 1]; - cache->next_search_offset = entry->offset + entry->len; - cache->cached = false; - - return BTRFS_FIEMAP_FLUSH_CACHE; - } - - entry = &cache->entries[cache->entries_pos]; - entry->offset = cache->offset; - entry->phys = cache->phys; - entry->len = cache->len; - entry->flags = cache->flags; - cache->entries_pos++; - cache->extents_mapped++; - - if (cache->extents_mapped == fieinfo->fi_extents_max) { - cache->cached = false; - return 1; - } -assign: - cache->cached = true; - cache->offset = offset; - cache->phys = phys; - cache->len = len; - cache->flags = flags; - - return 0; -} - -/* - * Emit last fiemap cache - * - * The last fiemap cache may still be cached in the following case: - * 0 4k 8k - * |<- Fiemap range ->| - * |<------------ First extent ----------->| - * - * In this case, the first extent range will be cached but not emitted. - * So we must emit it before ending extent_fiemap(). - */ -static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo, - struct fiemap_cache *cache) -{ - int ret; - - if (!cache->cached) - return 0; - - ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys, - cache->len, cache->flags); - cache->cached = false; - if (ret > 0) - ret = 0; - return ret; -} - -static int fiemap_next_leaf_item(struct btrfs_inode *inode, struct btrfs_path *path) +static bool try_release_extent_state(struct extent_io_tree *tree, + struct folio *folio) { - struct extent_buffer *clone = path->nodes[0]; - struct btrfs_key key; - int slot; - int ret; + struct extent_state *cached_state = NULL; + u64 start = folio_pos(folio); + u64 end = start + folio_size(folio) - 1; + u32 range_bits; + u32 clear_bits; + bool ret = false; + int ret2; - path->slots[0]++; - if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) - return 0; + btrfs_get_range_bits(tree, start, end, &range_bits, &cached_state); /* - * Add a temporary extra ref to an already cloned extent buffer to - * prevent btrfs_next_leaf() freeing it, we want to reuse it to avoid - * the cost of allocating a new one. + * We can release the folio if it's locked only for ordered extent + * completion, since that doesn't require using the folio. */ - ASSERT(test_bit(EXTENT_BUFFER_UNMAPPED, &clone->bflags)); - atomic_inc(&clone->refs); - - ret = btrfs_next_leaf(inode->root, path); - if (ret != 0) + if ((range_bits & EXTENT_LOCKED) && + !(range_bits & EXTENT_FINISHING_ORDERED)) goto out; + clear_bits = ~(EXTENT_LOCKED | EXTENT_NODATASUM | EXTENT_DELALLOC_NEW | + EXTENT_CTLBITS | EXTENT_QGROUP_RESERVED | + EXTENT_FINISHING_ORDERED); /* - * Don't bother with cloning if there are no more file extent items for - * our inode. + * At this point we can safely clear everything except the locked, + * nodatasum, delalloc new and finishing ordered bits. The delalloc new + * bit will be cleared by ordered extent completion. */ - btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); - if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY) { - ret = 1; - goto out; - } - - /* See the comment at fiemap_search_slot() about why we clone. */ - copy_extent_buffer_full(clone, path->nodes[0]); + ret2 = btrfs_clear_extent_bit(tree, start, end, clear_bits, &cached_state); /* - * Important to preserve the start field, for the optimizations when - * checking if extents are shared (see extent_fiemap()). + * If clear_extent_bit failed for enomem reasons, we can't allow the + * release to continue. */ - clone->start = path->nodes[0]->start; - - slot = path->slots[0]; - btrfs_release_path(path); - path->nodes[0] = clone; - path->slots[0] = slot; + if (ret2 == 0) + ret = true; out: - if (ret) - free_extent_buffer(clone); + btrfs_free_extent_state(cached_state); return ret; } /* - * Search for the first file extent item that starts at a given file offset or - * the one that starts immediately before that offset. - * Returns: 0 on success, < 0 on error, 1 if not found. - */ -static int fiemap_search_slot(struct btrfs_inode *inode, struct btrfs_path *path, - u64 file_offset) -{ - const u64 ino = btrfs_ino(inode); - struct btrfs_root *root = inode->root; - struct extent_buffer *clone; - struct btrfs_key key; - int slot; - int ret; - - key.objectid = ino; - key.type = BTRFS_EXTENT_DATA_KEY; - key.offset = file_offset; - - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - if (ret < 0) - return ret; - - if (ret > 0 && path->slots[0] > 0) { - btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1); - if (key.objectid == ino && key.type == BTRFS_EXTENT_DATA_KEY) - path->slots[0]--; - } - - if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { - ret = btrfs_next_leaf(root, path); - if (ret != 0) - return ret; - - btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); - if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) - return 1; - } - - /* - * We clone the leaf and use it during fiemap. This is because while - * using the leaf we do expensive things like checking if an extent is - * shared, which can take a long time. In order to prevent blocking - * other tasks for too long, we use a clone of the leaf. We have locked - * the file range in the inode's io tree, so we know none of our file - * extent items can change. This way we avoid blocking other tasks that - * want to insert items for other inodes in the same leaf or b+tree - * rebalance operations (triggered for example when someone is trying - * to push items into this leaf when trying to insert an item in a - * neighbour leaf). - * We also need the private clone because holding a read lock on an - * extent buffer of the subvolume's b+tree will make lockdep unhappy - * when we check if extents are shared, as backref walking may need to - * lock the same leaf we are processing. - */ - clone = btrfs_clone_extent_buffer(path->nodes[0]); - if (!clone) - return -ENOMEM; - - slot = path->slots[0]; - btrfs_release_path(path); - path->nodes[0] = clone; - path->slots[0] = slot; - - return 0; -} - -/* - * Process a range which is a hole or a prealloc extent in the inode's subvolume - * btree. If @disk_bytenr is 0, we are dealing with a hole, otherwise a prealloc - * extent. The end offset (@end) is inclusive. + * a helper for release_folio. As long as there are no locked extents + * in the range corresponding to the page, both state records and extent + * map records are removed */ -static int fiemap_process_hole(struct btrfs_inode *inode, - struct fiemap_extent_info *fieinfo, - struct fiemap_cache *cache, - struct extent_state **delalloc_cached_state, - struct btrfs_backref_share_check_ctx *backref_ctx, - u64 disk_bytenr, u64 extent_offset, - u64 extent_gen, - u64 start, u64 end) +bool try_release_extent_mapping(struct folio *folio, gfp_t mask) { - const u64 i_size = i_size_read(&inode->vfs_inode); - u64 cur_offset = start; - u64 last_delalloc_end = 0; - u32 prealloc_flags = FIEMAP_EXTENT_UNWRITTEN; - bool checked_extent_shared = false; - int ret; - - /* - * There can be no delalloc past i_size, so don't waste time looking for - * it beyond i_size. - */ - while (cur_offset < end && cur_offset < i_size) { - u64 delalloc_start; - u64 delalloc_end; - u64 prealloc_start; - u64 prealloc_len = 0; - bool delalloc; - - delalloc = btrfs_find_delalloc_in_range(inode, cur_offset, end, - delalloc_cached_state, - &delalloc_start, - &delalloc_end); - if (!delalloc) + u64 start = folio_pos(folio); + u64 end = start + folio_size(folio) - 1; + struct btrfs_inode *inode = folio_to_inode(folio); + struct extent_io_tree *io_tree = &inode->io_tree; + + while (start <= end) { + const u64 cur_gen = btrfs_get_fs_generation(inode->root->fs_info); + const u64 len = end - start + 1; + struct extent_map_tree *extent_tree = &inode->extent_tree; + struct extent_map *em; + + write_lock(&extent_tree->lock); + em = btrfs_lookup_extent_mapping(extent_tree, start, len); + if (!em) { + write_unlock(&extent_tree->lock); break; - - /* - * If this is a prealloc extent we have to report every section - * of it that has no delalloc. - */ - if (disk_bytenr != 0) { - if (last_delalloc_end == 0) { - prealloc_start = start; - prealloc_len = delalloc_start - start; - } else { - prealloc_start = last_delalloc_end + 1; - prealloc_len = delalloc_start - prealloc_start; - } } - - if (prealloc_len > 0) { - if (!checked_extent_shared && fieinfo->fi_extents_max) { - ret = btrfs_is_data_extent_shared(inode, - disk_bytenr, - extent_gen, - backref_ctx); - if (ret < 0) - return ret; - else if (ret > 0) - prealloc_flags |= FIEMAP_EXTENT_SHARED; - - checked_extent_shared = true; - } - ret = emit_fiemap_extent(fieinfo, cache, prealloc_start, - disk_bytenr + extent_offset, - prealloc_len, prealloc_flags); - if (ret) - return ret; - extent_offset += prealloc_len; - } - - ret = emit_fiemap_extent(fieinfo, cache, delalloc_start, 0, - delalloc_end + 1 - delalloc_start, - FIEMAP_EXTENT_DELALLOC | - FIEMAP_EXTENT_UNKNOWN); - if (ret) - return ret; - - last_delalloc_end = delalloc_end; - cur_offset = delalloc_end + 1; - extent_offset += cur_offset - delalloc_start; - cond_resched(); - } - - /* - * Either we found no delalloc for the whole prealloc extent or we have - * a prealloc extent that spans i_size or starts at or after i_size. - */ - if (disk_bytenr != 0 && last_delalloc_end < end) { - u64 prealloc_start; - u64 prealloc_len; - - if (last_delalloc_end == 0) { - prealloc_start = start; - prealloc_len = end + 1 - start; - } else { - prealloc_start = last_delalloc_end + 1; - prealloc_len = end + 1 - prealloc_start; - } - - if (!checked_extent_shared && fieinfo->fi_extents_max) { - ret = btrfs_is_data_extent_shared(inode, - disk_bytenr, - extent_gen, - backref_ctx); - if (ret < 0) - return ret; - else if (ret > 0) - prealloc_flags |= FIEMAP_EXTENT_SHARED; - } - ret = emit_fiemap_extent(fieinfo, cache, prealloc_start, - disk_bytenr + extent_offset, - prealloc_len, prealloc_flags); - if (ret) - return ret; - } - - return 0; -} - -static int fiemap_find_last_extent_offset(struct btrfs_inode *inode, - struct btrfs_path *path, - u64 *last_extent_end_ret) -{ - const u64 ino = btrfs_ino(inode); - struct btrfs_root *root = inode->root; - struct extent_buffer *leaf; - struct btrfs_file_extent_item *ei; - struct btrfs_key key; - u64 disk_bytenr; - int ret; - - /* - * Lookup the last file extent. We're not using i_size here because - * there might be preallocation past i_size. - */ - ret = btrfs_lookup_file_extent(NULL, root, path, ino, (u64)-1, 0); - /* There can't be a file extent item at offset (u64)-1 */ - ASSERT(ret != 0); - if (ret < 0) - return ret; - - /* - * For a non-existing key, btrfs_search_slot() always leaves us at a - * slot > 0, except if the btree is empty, which is impossible because - * at least it has the inode item for this inode and all the items for - * the root inode 256. - */ - ASSERT(path->slots[0] > 0); - path->slots[0]--; - leaf = path->nodes[0]; - btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); - if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) { - /* No file extent items in the subvolume tree. */ - *last_extent_end_ret = 0; - return 0; - } - - /* - * For an inline extent, the disk_bytenr is where inline data starts at, - * so first check if we have an inline extent item before checking if we - * have an implicit hole (disk_bytenr == 0). - */ - ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); - if (btrfs_file_extent_type(leaf, ei) == BTRFS_FILE_EXTENT_INLINE) { - *last_extent_end_ret = btrfs_file_extent_end(path); - return 0; - } - - /* - * Find the last file extent item that is not a hole (when NO_HOLES is - * not enabled). This should take at most 2 iterations in the worst - * case: we have one hole file extent item at slot 0 of a leaf and - * another hole file extent item as the last item in the previous leaf. - * This is because we merge file extent items that represent holes. - */ - disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei); - while (disk_bytenr == 0) { - ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY); - if (ret < 0) { - return ret; - } else if (ret > 0) { - /* No file extent items that are not holes. */ - *last_extent_end_ret = 0; - return 0; + if ((em->flags & EXTENT_FLAG_PINNED) || em->start != start) { + write_unlock(&extent_tree->lock); + btrfs_free_extent_map(em); + break; } - leaf = path->nodes[0]; - ei = btrfs_item_ptr(leaf, path->slots[0], - struct btrfs_file_extent_item); - disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei); - } - - *last_extent_end_ret = btrfs_file_extent_end(path); - return 0; -} - -int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo, - u64 start, u64 len) -{ - const u64 ino = btrfs_ino(inode); - struct extent_state *cached_state = NULL; - struct extent_state *delalloc_cached_state = NULL; - struct btrfs_path *path; - struct fiemap_cache cache = { 0 }; - struct btrfs_backref_share_check_ctx *backref_ctx; - u64 last_extent_end; - u64 prev_extent_end; - u64 range_start; - u64 range_end; - const u64 sectorsize = inode->root->fs_info->sectorsize; - bool stopped = false; - int ret; - - cache.entries_size = PAGE_SIZE / sizeof(struct btrfs_fiemap_entry); - cache.entries = kmalloc_array(cache.entries_size, - sizeof(struct btrfs_fiemap_entry), - GFP_KERNEL); - backref_ctx = btrfs_alloc_backref_share_check_ctx(); - path = btrfs_alloc_path(); - if (!cache.entries || !backref_ctx || !path) { - ret = -ENOMEM; - goto out; - } - -restart: - range_start = round_down(start, sectorsize); - range_end = round_up(start + len, sectorsize); - prev_extent_end = range_start; - - lock_extent(&inode->io_tree, range_start, range_end, &cached_state); - - ret = fiemap_find_last_extent_offset(inode, path, &last_extent_end); - if (ret < 0) - goto out_unlock; - btrfs_release_path(path); - - path->reada = READA_FORWARD; - ret = fiemap_search_slot(inode, path, range_start); - if (ret < 0) { - goto out_unlock; - } else if (ret > 0) { + if (btrfs_test_range_bit_exists(io_tree, em->start, + btrfs_extent_map_end(em) - 1, + EXTENT_LOCKED)) + goto next; /* - * No file extent item found, but we may have delalloc between - * the current offset and i_size. So check for that. + * If it's not in the list of modified extents, used by a fast + * fsync, we can remove it. If it's being logged we can safely + * remove it since fsync took an extra reference on the em. */ - ret = 0; - goto check_eof_delalloc; - } - - while (prev_extent_end < range_end) { - struct extent_buffer *leaf = path->nodes[0]; - struct btrfs_file_extent_item *ei; - struct btrfs_key key; - u64 extent_end; - u64 extent_len; - u64 extent_offset = 0; - u64 extent_gen; - u64 disk_bytenr = 0; - u64 flags = 0; - int extent_type; - u8 compression; - - btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); - if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) - break; - - extent_end = btrfs_file_extent_end(path); - + if (list_empty(&em->list) || (em->flags & EXTENT_FLAG_LOGGING)) + goto remove_em; /* - * The first iteration can leave us at an extent item that ends - * before our range's start. Move to the next item. + * If it's in the list of modified extents, remove it only if + * its generation is older then the current one, in which case + * we don't need it for a fast fsync. Otherwise don't remove it, + * we could be racing with an ongoing fast fsync that could miss + * the new extent. */ - if (extent_end <= range_start) - goto next_item; - - backref_ctx->curr_leaf_bytenr = leaf->start; - - /* We have in implicit hole (NO_HOLES feature enabled). */ - if (prev_extent_end < key.offset) { - const u64 hole_end = min(key.offset, range_end) - 1; + if (em->generation >= cur_gen) + goto next; +remove_em: + /* + * We only remove extent maps that are not in the list of + * modified extents or that are in the list but with a + * generation lower then the current generation, so there is no + * need to set the full fsync flag on the inode (it hurts the + * fsync performance for workloads with a data size that exceeds + * or is close to the system's memory). + */ + btrfs_remove_extent_mapping(inode, em); + /* Once for the inode's extent map tree. */ + btrfs_free_extent_map(em); +next: + start = btrfs_extent_map_end(em); + write_unlock(&extent_tree->lock); - ret = fiemap_process_hole(inode, fieinfo, &cache, - &delalloc_cached_state, - backref_ctx, 0, 0, 0, - prev_extent_end, hole_end); - if (ret < 0) { - goto out_unlock; - } else if (ret > 0) { - /* fiemap_fill_next_extent() told us to stop. */ - stopped = true; - break; - } + /* Once for us, for the lookup_extent_mapping() reference. */ + btrfs_free_extent_map(em); - /* We've reached the end of the fiemap range, stop. */ - if (key.offset >= range_end) { - stopped = true; + if (need_resched()) { + /* + * If we need to resched but we can't block just exit + * and leave any remaining extent maps. + */ + if (!gfpflags_allow_blocking(mask)) break; - } - } - - extent_len = extent_end - key.offset; - ei = btrfs_item_ptr(leaf, path->slots[0], - struct btrfs_file_extent_item); - compression = btrfs_file_extent_compression(leaf, ei); - extent_type = btrfs_file_extent_type(leaf, ei); - extent_gen = btrfs_file_extent_generation(leaf, ei); - - if (extent_type != BTRFS_FILE_EXTENT_INLINE) { - disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei); - if (compression == BTRFS_COMPRESS_NONE) - extent_offset = btrfs_file_extent_offset(leaf, ei); - } - - if (compression != BTRFS_COMPRESS_NONE) - flags |= FIEMAP_EXTENT_ENCODED; - - if (extent_type == BTRFS_FILE_EXTENT_INLINE) { - flags |= FIEMAP_EXTENT_DATA_INLINE; - flags |= FIEMAP_EXTENT_NOT_ALIGNED; - ret = emit_fiemap_extent(fieinfo, &cache, key.offset, 0, - extent_len, flags); - } else if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { - ret = fiemap_process_hole(inode, fieinfo, &cache, - &delalloc_cached_state, - backref_ctx, - disk_bytenr, extent_offset, - extent_gen, key.offset, - extent_end - 1); - } else if (disk_bytenr == 0) { - /* We have an explicit hole. */ - ret = fiemap_process_hole(inode, fieinfo, &cache, - &delalloc_cached_state, - backref_ctx, 0, 0, 0, - key.offset, extent_end - 1); - } else { - /* We have a regular extent. */ - if (fieinfo->fi_extents_max) { - ret = btrfs_is_data_extent_shared(inode, - disk_bytenr, - extent_gen, - backref_ctx); - if (ret < 0) - goto out_unlock; - else if (ret > 0) - flags |= FIEMAP_EXTENT_SHARED; - } - ret = emit_fiemap_extent(fieinfo, &cache, key.offset, - disk_bytenr + extent_offset, - extent_len, flags); - } - - if (ret < 0) { - goto out_unlock; - } else if (ret > 0) { - /* emit_fiemap_extent() told us to stop. */ - stopped = true; - break; - } - - prev_extent_end = extent_end; -next_item: - if (fatal_signal_pending(current)) { - ret = -EINTR; - goto out_unlock; - } - - ret = fiemap_next_leaf_item(inode, path); - if (ret < 0) { - goto out_unlock; - } else if (ret > 0) { - /* No more file extent items for this inode. */ - break; - } - cond_resched(); - } - -check_eof_delalloc: - if (!stopped && prev_extent_end < range_end) { - ret = fiemap_process_hole(inode, fieinfo, &cache, - &delalloc_cached_state, backref_ctx, - 0, 0, 0, prev_extent_end, range_end - 1); - if (ret < 0) - goto out_unlock; - prev_extent_end = range_end; - } - - if (cache.cached && cache.offset + cache.len >= last_extent_end) { - const u64 i_size = i_size_read(&inode->vfs_inode); - - if (prev_extent_end < i_size) { - u64 delalloc_start; - u64 delalloc_end; - bool delalloc; - - delalloc = btrfs_find_delalloc_in_range(inode, - prev_extent_end, - i_size - 1, - &delalloc_cached_state, - &delalloc_start, - &delalloc_end); - if (!delalloc) - cache.flags |= FIEMAP_EXTENT_LAST; - } else { - cache.flags |= FIEMAP_EXTENT_LAST; + cond_resched(); } } - -out_unlock: - unlock_extent(&inode->io_tree, range_start, range_end, &cached_state); - - if (ret == BTRFS_FIEMAP_FLUSH_CACHE) { - btrfs_release_path(path); - ret = flush_fiemap_cache(fieinfo, &cache); - if (ret) - goto out; - len -= cache.next_search_offset - start; - start = cache.next_search_offset; - goto restart; - } else if (ret < 0) { - goto out; - } - - /* - * Must free the path before emitting to the fiemap buffer because we - * may have a non-cloned leaf and if the fiemap buffer is memory mapped - * to a file, a write into it (through btrfs_page_mkwrite()) may trigger - * waiting for an ordered extent that in order to complete needs to - * modify that leaf, therefore leading to a deadlock. - */ - btrfs_free_path(path); - path = NULL; - - ret = flush_fiemap_cache(fieinfo, &cache); - if (ret) - goto out; - - ret = emit_last_fiemap_cache(fieinfo, &cache); -out: - free_extent_state(delalloc_cached_state); - kfree(cache.entries); - btrfs_free_backref_share_ctx(backref_ctx); - btrfs_free_path(path); - return ret; -} - -static void __free_extent_buffer(struct extent_buffer *eb) -{ - kmem_cache_free(extent_buffer_cache, eb); + return try_release_extent_state(io_tree, folio); } static int extent_buffer_under_io(const struct extent_buffer *eb) @@ -3329,7 +2729,7 @@ static int extent_buffer_under_io(const struct extent_buffer *eb) test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); } -static bool folio_range_has_eb(struct btrfs_fs_info *fs_info, struct folio *folio) +static bool folio_range_has_eb(struct folio *folio) { struct btrfs_subpage *subpage; @@ -3339,19 +2739,14 @@ static bool folio_range_has_eb(struct btrfs_fs_info *fs_info, struct folio *foli subpage = folio_get_private(folio); if (atomic_read(&subpage->eb_refs)) return true; - /* - * Even there is no eb refs here, we may still have - * end_page_read() call relying on page::private. - */ - if (atomic_read(&subpage->readers)) - return true; } return false; } -static void detach_extent_buffer_folio(struct extent_buffer *eb, struct folio *folio) +static void detach_extent_buffer_folio(const struct extent_buffer *eb, struct folio *folio) { struct btrfs_fs_info *fs_info = eb->fs_info; + struct address_space *mapping = folio->mapping; const bool mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); /* @@ -3359,21 +2754,20 @@ static void detach_extent_buffer_folio(struct extent_buffer *eb, struct folio *f * be done under the i_private_lock. */ if (mapped) - spin_lock(&folio->mapping->i_private_lock); + spin_lock(&mapping->i_private_lock); if (!folio_test_private(folio)) { if (mapped) - spin_unlock(&folio->mapping->i_private_lock); + spin_unlock(&mapping->i_private_lock); return; } - if (fs_info->nodesize >= PAGE_SIZE) { + if (!btrfs_meta_is_subpage(fs_info)) { /* - * We do this since we'll remove the pages after we've - * removed the eb from the radix tree, so we could race - * and have this page now attached to the new eb. So - * only clear folio if it's still connected to - * this eb. + * We do this since we'll remove the pages after we've removed + * the eb from the xarray, so we could race and have this page + * now attached to the new eb. So only clear folio if it's + * still connected to this eb. */ if (folio_test_private(folio) && folio_get_private(folio) == eb) { BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); @@ -3383,7 +2777,7 @@ static void detach_extent_buffer_folio(struct extent_buffer *eb, struct folio *f folio_detach_private(folio); } if (mapped) - spin_unlock(&folio->mapping->i_private_lock); + spin_unlock(&mapping->i_private_lock); return; } @@ -3393,7 +2787,7 @@ static void detach_extent_buffer_folio(struct extent_buffer *eb, struct folio *f * attached to one dummy eb, no sharing. */ if (!mapped) { - btrfs_detach_subpage(fs_info, folio); + btrfs_detach_subpage(fs_info, folio, BTRFS_SUBPAGE_METADATA); return; } @@ -3403,14 +2797,14 @@ static void detach_extent_buffer_folio(struct extent_buffer *eb, struct folio *f * We can only detach the folio private if there are no other ebs in the * page range and no unfinished IO. */ - if (!folio_range_has_eb(fs_info, folio)) - btrfs_detach_subpage(fs_info, folio); + if (!folio_range_has_eb(folio)) + btrfs_detach_subpage(fs_info, folio, BTRFS_SUBPAGE_METADATA); - spin_unlock(&folio->mapping->i_private_lock); + spin_unlock(&mapping->i_private_lock); } -/* Release all pages attached to the extent buffer */ -static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) +/* Release all folios attached to the extent buffer */ +static void btrfs_release_extent_buffer_folios(const struct extent_buffer *eb) { ASSERT(!extent_buffer_under_io(eb)); @@ -3421,9 +2815,6 @@ static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) continue; detach_extent_buffer_folio(eb, folio); - - /* One for when we allocated the folio. */ - folio_put(folio); } } @@ -3432,20 +2823,19 @@ static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) */ static inline void btrfs_release_extent_buffer(struct extent_buffer *eb) { - btrfs_release_extent_buffer_pages(eb); + btrfs_release_extent_buffer_folios(eb); btrfs_leak_debug_del_eb(eb); - __free_extent_buffer(eb); + kmem_cache_free(extent_buffer_cache, eb); } -static struct extent_buffer * -__alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, - unsigned long len) +static struct extent_buffer *__alloc_extent_buffer(struct btrfs_fs_info *fs_info, + u64 start) { struct extent_buffer *eb = NULL; eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL); eb->start = start; - eb->len = len; + eb->len = fs_info->nodesize; eb->fs_info = fs_info; init_rwsem(&eb->lock); @@ -3454,18 +2844,36 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, spin_lock_init(&eb->refs_lock); atomic_set(&eb->refs, 1); - ASSERT(len <= BTRFS_MAX_METADATA_BLOCKSIZE); + ASSERT(eb->len <= BTRFS_MAX_METADATA_BLOCKSIZE); return eb; } +/* + * For use in eb allocation error cleanup paths, as btrfs_release_extent_buffer() + * does not call folio_put(), and we need to set the folios to NULL so that + * btrfs_release_extent_buffer() will not detach them a second time. + */ +static void cleanup_extent_buffer_folios(struct extent_buffer *eb) +{ + const int num_folios = num_extent_folios(eb); + + /* We canont use num_extent_folios() as loop bound as eb->folios changes. */ + for (int i = 0; i < num_folios; i++) { + ASSERT(eb->folios[i]); + detach_extent_buffer_folio(eb, eb->folios[i]); + folio_put(eb->folios[i]); + eb->folios[i] = NULL; + } +} + struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src) { struct extent_buffer *new; - int num_folios = num_extent_folios(src); + int num_folios; int ret; - new = __alloc_extent_buffer(src->fs_info, src->start, src->len); + new = __alloc_extent_buffer(src->fs_info, src->start); if (new == NULL) return NULL; @@ -3476,80 +2884,79 @@ struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src) */ set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags); - ret = alloc_eb_folio_array(new, 0); - if (ret) { - btrfs_release_extent_buffer(new); - return NULL; - } + ret = alloc_eb_folio_array(new, false); + if (ret) + goto release_eb; + ASSERT(num_extent_folios(src) == num_extent_folios(new), + "%d != %d", num_extent_folios(src), num_extent_folios(new)); + /* Explicitly use the cached num_extent value from now on. */ + num_folios = num_extent_folios(src); for (int i = 0; i < num_folios; i++) { struct folio *folio = new->folios[i]; - int ret; ret = attach_extent_buffer_folio(new, folio, NULL); - if (ret < 0) { - btrfs_release_extent_buffer(new); - return NULL; - } + if (ret < 0) + goto cleanup_folios; WARN_ON(folio_test_dirty(folio)); } + for (int i = 0; i < num_folios; i++) + folio_put(new->folios[i]); + copy_extent_buffer_full(new, src); set_extent_buffer_uptodate(new); return new; + +cleanup_folios: + cleanup_extent_buffer_folios(new); +release_eb: + btrfs_release_extent_buffer(new); + return NULL; } -struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, - u64 start, unsigned long len) +struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, + u64 start) { struct extent_buffer *eb; - int num_folios = 0; int ret; - eb = __alloc_extent_buffer(fs_info, start, len); + eb = __alloc_extent_buffer(fs_info, start); if (!eb) return NULL; - ret = alloc_eb_folio_array(eb, 0); + ret = alloc_eb_folio_array(eb, false); if (ret) - goto err; + goto release_eb; - num_folios = num_extent_folios(eb); - for (int i = 0; i < num_folios; i++) { + for (int i = 0; i < num_extent_folios(eb); i++) { ret = attach_extent_buffer_folio(eb, eb->folios[i], NULL); if (ret < 0) - goto err; + goto cleanup_folios; } + for (int i = 0; i < num_extent_folios(eb); i++) + folio_put(eb->folios[i]); set_extent_buffer_uptodate(eb); btrfs_set_header_nritems(eb, 0); set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); return eb; -err: - for (int i = 0; i < num_folios; i++) { - if (eb->folios[i]) { - detach_extent_buffer_folio(eb, eb->folios[i]); - __folio_put(eb->folios[i]); - } - } - __free_extent_buffer(eb); - return NULL; -} -struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, - u64 start) -{ - return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize); +cleanup_folios: + cleanup_extent_buffer_folios(eb); +release_eb: + btrfs_release_extent_buffer(eb); + return NULL; } static void check_buffer_tree_ref(struct extent_buffer *eb) { int refs; /* - * The TREE_REF bit is first set when the extent_buffer is added - * to the radix tree. It is also reset, if unset, when a new reference - * is created by find_extent_buffer. + * The TREE_REF bit is first set when the extent_buffer is added to the + * xarray. It is also reset, if unset, when a new reference is created + * by find_extent_buffer. * * It is only cleared in two cases: freeing the last non-tree * reference to the extent_buffer when its STALE bit is set or @@ -3561,13 +2968,12 @@ static void check_buffer_tree_ref(struct extent_buffer *eb) * conditions between the calls to check_buffer_tree_ref in those * codepaths and clearing TREE_REF in try_release_extent_buffer. * - * The actual lifetime of the extent_buffer in the radix tree is - * adequately protected by the refcount, but the TREE_REF bit and - * its corresponding reference are not. To protect against this - * class of races, we call check_buffer_tree_ref from the codepaths - * which trigger io. Note that once io is initiated, TREE_REF can no - * longer be cleared, so that is the moment at which any such race is - * best fixed. + * The actual lifetime of the extent_buffer in the xarray is adequately + * protected by the refcount, but the TREE_REF bit and its corresponding + * reference are not. To protect against this class of races, we call + * check_buffer_tree_ref() from the code paths which trigger io. Note that + * once io is initiated, TREE_REF can no longer be cleared, so that is + * the moment at which any such race is best fixed. */ refs = atomic_read(&eb->refs); if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) @@ -3581,11 +2987,9 @@ static void check_buffer_tree_ref(struct extent_buffer *eb) static void mark_extent_buffer_accessed(struct extent_buffer *eb) { - int num_folios= num_extent_folios(eb); - check_buffer_tree_ref(eb); - for (int i = 0; i < num_folios; i++) + for (int i = 0; i < num_extent_folios(eb); i++) folio_mark_accessed(eb->folios[i]); } @@ -3618,10 +3022,10 @@ struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, return eb; } -#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, u64 start) { +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS struct extent_buffer *eb, *exists = NULL; int ret; @@ -3633,45 +3037,48 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, return ERR_PTR(-ENOMEM); eb->fs_info = fs_info; again: - ret = radix_tree_preload(GFP_NOFS); - if (ret) { - exists = ERR_PTR(ret); - goto free_eb; + xa_lock_irq(&fs_info->buffer_tree); + exists = __xa_cmpxchg(&fs_info->buffer_tree, start >> fs_info->sectorsize_bits, + NULL, eb, GFP_NOFS); + if (xa_is_err(exists)) { + ret = xa_err(exists); + xa_unlock_irq(&fs_info->buffer_tree); + btrfs_release_extent_buffer(eb); + return ERR_PTR(ret); } - spin_lock(&fs_info->buffer_lock); - ret = radix_tree_insert(&fs_info->buffer_radix, - start >> fs_info->sectorsize_bits, eb); - spin_unlock(&fs_info->buffer_lock); - radix_tree_preload_end(); - if (ret == -EEXIST) { - exists = find_extent_buffer(fs_info, start); - if (exists) - goto free_eb; - else + if (exists) { + if (!atomic_inc_not_zero(&exists->refs)) { + /* The extent buffer is being freed, retry. */ + xa_unlock_irq(&fs_info->buffer_tree); goto again; + } + xa_unlock_irq(&fs_info->buffer_tree); + btrfs_release_extent_buffer(eb); + return exists; } + xa_unlock_irq(&fs_info->buffer_tree); check_buffer_tree_ref(eb); - set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags); return eb; -free_eb: - btrfs_release_extent_buffer(eb); - return exists; -} +#else + /* Stub to avoid linker error when compiled with optimizations turned off. */ + return NULL; #endif +} -static struct extent_buffer *grab_extent_buffer( - struct btrfs_fs_info *fs_info, struct page *page) +static struct extent_buffer *grab_extent_buffer(struct btrfs_fs_info *fs_info, + struct folio *folio) { - struct folio *folio = page_folio(page); struct extent_buffer *exists; + lockdep_assert_held(&folio->mapping->i_private_lock); + /* - * For subpage case, we completely rely on radix tree to ensure we - * don't try to insert two ebs for the same bytenr. So here we always - * return NULL and just continue. + * For subpage case, we completely rely on xarray to ensure we don't try + * to insert two ebs for the same bytenr. So here we always return NULL + * and just continue. */ - if (fs_info->nodesize < PAGE_SIZE) + if (btrfs_meta_is_subpage(fs_info)) return NULL; /* Page not yet attached to an extent buffer */ @@ -3679,7 +3086,7 @@ static struct extent_buffer *grab_extent_buffer( return NULL; /* - * We could have already allocated an eb for this page and attached one + * We could have already allocated an eb for this folio and attached one * so lets see if we can get a ref on the existing eb, and if we can we * know it's good and we can just return that one, else we know we can * just overwrite folio private. @@ -3688,31 +3095,33 @@ static struct extent_buffer *grab_extent_buffer( if (atomic_inc_not_zero(&exists->refs)) return exists; - WARN_ON(PageDirty(page)); + WARN_ON(folio_test_dirty(folio)); folio_detach_private(folio); return NULL; } -static int check_eb_alignment(struct btrfs_fs_info *fs_info, u64 start) +/* + * Validate alignment constraints of eb at logical address @start. + */ +static bool check_eb_alignment(struct btrfs_fs_info *fs_info, u64 start) { if (!IS_ALIGNED(start, fs_info->sectorsize)) { btrfs_err(fs_info, "bad tree block start %llu", start); - return -EINVAL; + return true; } - if (fs_info->nodesize < PAGE_SIZE && - offset_in_page(start) + fs_info->nodesize > PAGE_SIZE) { + if (fs_info->nodesize < PAGE_SIZE && !IS_ALIGNED(start, fs_info->nodesize)) { btrfs_err(fs_info, - "tree block crosses page boundary, start %llu nodesize %u", + "tree block is not nodesize aligned, start %llu nodesize %u", start, fs_info->nodesize); - return -EINVAL; + return true; } if (fs_info->nodesize >= PAGE_SIZE && !PAGE_ALIGNED(start)) { btrfs_err(fs_info, "tree block is not page aligned, start %llu nodesize %u", start, fs_info->nodesize); - return -EINVAL; + return true; } if (!IS_ALIGNED(start, fs_info->nodesize) && !test_and_set_bit(BTRFS_FS_UNALIGNED_TREE_BLOCK, &fs_info->flags)) { @@ -3720,10 +3129,9 @@ static int check_eb_alignment(struct btrfs_fs_info *fs_info, u64 start) "tree block not nodesize aligned, start %llu nodesize %u, can be resolved by a full metadata balance", start, fs_info->nodesize); } - return 0; + return false; } - /* * Return 0 if eb->folios[i] is attached to btree inode successfully. * Return >0 if there is already another extent buffer for the range, @@ -3733,6 +3141,7 @@ static int check_eb_alignment(struct btrfs_fs_info *fs_info, u64 start) * The caller needs to free the existing folios and retry using the same order. */ static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i, + struct btrfs_subpage *prealloc, struct extent_buffer **found_eb_ret) { @@ -3748,10 +3157,11 @@ static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i, ASSERT(eb->folios[i]); retry: + existing_folio = NULL; ret = filemap_add_folio(mapping, eb->folios[i], index + i, GFP_NOFS | __GFP_NOFAIL); if (!ret) - return 0; + goto finish; existing_folio = filemap_lock_folio(mapping, index + i); /* The page cache only exists for a very short time, just retry. */ @@ -3767,21 +3177,20 @@ retry: return -EAGAIN; } - if (fs_info->nodesize < PAGE_SIZE) { - /* - * We're going to reuse the existing page, can drop our page - * and subpage structure now. - */ +finish: + spin_lock(&mapping->i_private_lock); + if (existing_folio && btrfs_meta_is_subpage(fs_info)) { + /* We're going to reuse the existing page, can drop our folio now. */ __free_page(folio_page(eb->folios[i], 0)); eb->folios[i] = existing_folio; - } else { + } else if (existing_folio) { struct extent_buffer *existing_eb; - existing_eb = grab_extent_buffer(fs_info, - folio_page(existing_folio, 0)); + existing_eb = grab_extent_buffer(fs_info, existing_folio); if (existing_eb) { /* The extent buffer still exists, we can use it directly. */ *found_eb_ret = existing_eb; + spin_unlock(&mapping->i_private_lock); folio_unlock(existing_folio); folio_put(existing_folio); return 1; @@ -3790,18 +3199,31 @@ retry: __free_page(folio_page(eb->folios[i], 0)); eb->folios[i] = existing_folio; } + eb->folio_size = folio_size(eb->folios[i]); + eb->folio_shift = folio_shift(eb->folios[i]); + /* Should not fail, as we have preallocated the memory. */ + ret = attach_extent_buffer_folio(eb, eb->folios[i], prealloc); + ASSERT(!ret); + /* + * To inform we have an extra eb under allocation, so that + * detach_extent_buffer_page() won't release the folio private when the + * eb hasn't been inserted into the xarray yet. + * + * The ref will be decreased when the eb releases the page, in + * detach_extent_buffer_page(). Thus needs no special handling in the + * error path. + */ + btrfs_folio_inc_eb_refs(fs_info, eb->folios[i]); + spin_unlock(&mapping->i_private_lock); return 0; } struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, u64 owner_root, int level) { - unsigned long len = fs_info->nodesize; - int num_folios; int attached = 0; struct extent_buffer *eb; struct extent_buffer *existing_eb = NULL; - struct address_space *mapping = fs_info->btree_inode->i_mapping; struct btrfs_subpage *prealloc = NULL; u64 lockdep_owner = owner_root; bool page_contig = true; @@ -3826,7 +3248,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, if (eb) return eb; - eb = __alloc_extent_buffer(fs_info, start, len); + eb = __alloc_extent_buffer(fs_info, start); if (!eb) return ERR_PTR(-ENOMEM); @@ -3846,8 +3268,8 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, * The memory will be freed by attach_extent_buffer_page() or freed * manually if we exit earlier. */ - if (fs_info->nodesize < PAGE_SIZE) { - prealloc = btrfs_alloc_subpage(fs_info, BTRFS_SUBPAGE_METADATA); + if (btrfs_meta_is_subpage(fs_info)) { + prealloc = btrfs_alloc_subpage(fs_info, PAGE_SIZE, BTRFS_SUBPAGE_METADATA); if (IS_ERR(prealloc)) { ret = PTR_ERR(prealloc); goto out; @@ -3856,18 +3278,17 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, reallocate: /* Allocate all pages first. */ - ret = alloc_eb_folio_array(eb, __GFP_NOFAIL); + ret = alloc_eb_folio_array(eb, true); if (ret < 0) { btrfs_free_subpage(prealloc); goto out; } - num_folios = num_extent_folios(eb); /* Attach all pages to the filemap. */ - for (int i = 0; i < num_folios; i++) { + for (int i = 0; i < num_extent_folios(eb); i++) { struct folio *folio; - ret = attach_eb_folio_to_filemap(eb, i, &existing_eb); + ret = attach_eb_folio_to_filemap(eb, i, prealloc, &existing_eb); if (ret > 0) { ASSERT(existing_eb); goto out; @@ -3893,7 +3314,7 @@ reallocate: * using 0-order folios. */ if (unlikely(ret == -EAGAIN)) { - ASSERT(0); + DEBUG_WARN("folio order mismatch between new eb and filemap"); goto reallocate; } attached++; @@ -3904,25 +3325,7 @@ reallocate: * and free the allocated page. */ folio = eb->folios[i]; - eb->folio_size = folio_size(folio); - eb->folio_shift = folio_shift(folio); - spin_lock(&mapping->i_private_lock); - /* Should not fail, as we have preallocated the memory */ - ret = attach_extent_buffer_folio(eb, folio, prealloc); - ASSERT(!ret); - /* - * To inform we have extra eb under allocation, so that - * detach_extent_buffer_page() won't release the folio private - * when the eb hasn't yet been inserted into radix tree. - * - * The ref will be decreased when the eb released the page, in - * detach_extent_buffer_page(). - * Thus needs no special handling in error path. - */ - btrfs_folio_inc_eb_refs(fs_info, folio); - spin_unlock(&mapping->i_private_lock); - - WARN_ON(btrfs_folio_test_dirty(fs_info, folio, eb->start, eb->len)); + WARN_ON(btrfs_meta_folio_test_dirty(folio, eb)); /* * Check if the current page is physically contiguous with previous eb @@ -3933,15 +3336,14 @@ reallocate: if (i && folio_page(eb->folios[i - 1], 0) + 1 != folio_page(folio, 0)) page_contig = false; - if (!btrfs_folio_test_uptodate(fs_info, folio, eb->start, eb->len)) + if (!btrfs_meta_folio_test_uptodate(folio, eb)) uptodate = 0; /* * We can't unlock the pages just yet since the extent buffer - * hasn't been properly inserted in the radix tree, this - * opens a race with btree_release_folio which can free a page - * while we are still filling in all pages for the buffer and - * we could crash. + * hasn't been properly inserted into the xarray, this opens a + * race with btree_release_folio() which can free a page while we + * are still filling in all pages for the buffer and we could crash. */ } if (uptodate) @@ -3950,34 +3352,42 @@ reallocate: if (page_contig) eb->addr = folio_address(eb->folios[0]) + offset_in_page(eb->start); again: - ret = radix_tree_preload(GFP_NOFS); - if (ret) + xa_lock_irq(&fs_info->buffer_tree); + existing_eb = __xa_cmpxchg(&fs_info->buffer_tree, + start >> fs_info->sectorsize_bits, NULL, eb, + GFP_NOFS); + if (xa_is_err(existing_eb)) { + ret = xa_err(existing_eb); + xa_unlock_irq(&fs_info->buffer_tree); goto out; - - spin_lock(&fs_info->buffer_lock); - ret = radix_tree_insert(&fs_info->buffer_radix, - start >> fs_info->sectorsize_bits, eb); - spin_unlock(&fs_info->buffer_lock); - radix_tree_preload_end(); - if (ret == -EEXIST) { - ret = 0; - existing_eb = find_extent_buffer(fs_info, start); - if (existing_eb) - goto out; - else + } + if (existing_eb) { + if (!atomic_inc_not_zero(&existing_eb->refs)) { + xa_unlock_irq(&fs_info->buffer_tree); goto again; + } + xa_unlock_irq(&fs_info->buffer_tree); + goto out; } + xa_unlock_irq(&fs_info->buffer_tree); + /* add one reference for the tree */ check_buffer_tree_ref(eb); - set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags); /* * Now it's safe to unlock the pages because any calls to * btree_release_folio will correctly detect that a page belongs to a * live buffer and won't free them prematurely. */ - for (int i = 0; i < num_folios; i++) - unlock_page(folio_page(eb->folios[i], 0)); + for (int i = 0; i < num_extent_folios(eb); i++) { + folio_unlock(eb->folios[i]); + /* + * A folio that has been added to an address_space mapping + * should not continue holding the refcount from its original + * allocation indefinitely. + */ + folio_put(eb->folios[i]); + } return eb; out: @@ -3991,26 +3401,22 @@ out: * want that to grab this eb, as we're getting ready to free it. So we * have to detach it first and then unlock it. * - * We have to drop our reference and NULL it out here because in the - * subpage case detaching does a btrfs_folio_dec_eb_refs() for our eb. - * Below when we call btrfs_release_extent_buffer() we will call - * detach_extent_buffer_folio() on our remaining pages in the !subpage - * case. If we left eb->folios[i] populated in the subpage case we'd - * double put our reference and be super sad. + * Note: the bounds is num_extent_pages() as we need to go through all slots. */ - for (int i = 0; i < attached; i++) { - ASSERT(eb->folios[i]); - detach_extent_buffer_folio(eb, eb->folios[i]); - unlock_page(folio_page(eb->folios[i], 0)); - folio_put(eb->folios[i]); + for (int i = 0; i < num_extent_pages(eb); i++) { + struct folio *folio = eb->folios[i]; + + if (i < attached) { + ASSERT(folio); + detach_extent_buffer_folio(eb, folio); + folio_unlock(folio); + } else if (!folio) { + continue; + } + + folio_put(folio); eb->folios[i] = NULL; } - /* - * Now all pages of that extent buffer is unmapped, set UNMAPPED flag, - * so it can be cleaned up without utlizing page->mapping. - */ - set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); - btrfs_release_extent_buffer(eb); if (ret < 0) return ERR_PTR(ret); @@ -4023,7 +3429,7 @@ static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head) struct extent_buffer *eb = container_of(head, struct extent_buffer, rcu_head); - __free_extent_buffer(eb); + kmem_cache_free(extent_buffer_cache, eb); } static int release_extent_buffer(struct extent_buffer *eb) @@ -4033,25 +3439,34 @@ static int release_extent_buffer(struct extent_buffer *eb) WARN_ON(atomic_read(&eb->refs) == 0); if (atomic_dec_and_test(&eb->refs)) { - if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) { - struct btrfs_fs_info *fs_info = eb->fs_info; + struct btrfs_fs_info *fs_info = eb->fs_info; - spin_unlock(&eb->refs_lock); + spin_unlock(&eb->refs_lock); - spin_lock(&fs_info->buffer_lock); - radix_tree_delete(&fs_info->buffer_radix, - eb->start >> fs_info->sectorsize_bits); - spin_unlock(&fs_info->buffer_lock); - } else { - spin_unlock(&eb->refs_lock); - } + /* + * We're erasing, theoretically there will be no allocations, so + * just use GFP_ATOMIC. + * + * We use cmpxchg instead of erase because we do not know if + * this eb is actually in the tree or not, we could be cleaning + * up an eb that we allocated but never inserted into the tree. + * Thus use cmpxchg to remove it from the tree if it is there, + * or leave the other entry if this isn't in the tree. + * + * The documentation says that putting a NULL value is the same + * as erase as long as XA_FLAGS_ALLOC is not set, which it isn't + * in this case. + */ + xa_cmpxchg_irq(&fs_info->buffer_tree, + eb->start >> fs_info->sectorsize_bits, eb, NULL, + GFP_ATOMIC); btrfs_leak_debug_del_eb(eb); - /* Should be safe to release our pages at this point */ - btrfs_release_extent_buffer_pages(eb); + /* Should be safe to release folios at this point. */ + btrfs_release_extent_buffer_folios(eb); #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) { - __free_extent_buffer(eb); + kmem_cache_free(extent_buffer_cache, eb); return 1; } #endif @@ -4107,38 +3522,21 @@ void free_extent_buffer_stale(struct extent_buffer *eb) release_extent_buffer(eb); } -static void btree_clear_folio_dirty(struct folio *folio) +static void btree_clear_folio_dirty_tag(struct folio *folio) { - ASSERT(folio_test_dirty(folio)); + ASSERT(!folio_test_dirty(folio)); ASSERT(folio_test_locked(folio)); - folio_clear_dirty_for_io(folio); xa_lock_irq(&folio->mapping->i_pages); if (!folio_test_dirty(folio)) - __xa_clear_mark(&folio->mapping->i_pages, - folio_index(folio), PAGECACHE_TAG_DIRTY); + __xa_clear_mark(&folio->mapping->i_pages, folio->index, + PAGECACHE_TAG_DIRTY); xa_unlock_irq(&folio->mapping->i_pages); } -static void clear_subpage_extent_buffer_dirty(const struct extent_buffer *eb) -{ - struct btrfs_fs_info *fs_info = eb->fs_info; - struct folio *folio = eb->folios[0]; - bool last; - - /* btree_clear_folio_dirty() needs page locked. */ - folio_lock(folio); - last = btrfs_subpage_clear_and_test_dirty(fs_info, folio, eb->start, eb->len); - if (last) - btree_clear_folio_dirty(folio); - folio_unlock(folio); - WARN_ON(atomic_read(&eb->refs) == 0); -} - void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, struct extent_buffer *eb) { struct btrfs_fs_info *fs_info = eb->fs_info; - int num_folios; btrfs_assert_tree_write_locked(eb); @@ -4154,7 +3552,7 @@ void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, * The actual zeroout of the buffer will happen later in * btree_csum_one_bio. */ - if (btrfs_is_zoned(fs_info)) { + if (btrfs_is_zoned(fs_info) && test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { set_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags); return; } @@ -4162,20 +3560,20 @@ void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, if (!test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) return; + buffer_tree_clear_mark(eb, PAGECACHE_TAG_DIRTY); percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, -eb->len, fs_info->dirty_metadata_batch); - if (eb->fs_info->nodesize < PAGE_SIZE) - return clear_subpage_extent_buffer_dirty(eb); - - num_folios = num_extent_folios(eb); - for (int i = 0; i < num_folios; i++) { + for (int i = 0; i < num_extent_folios(eb); i++) { struct folio *folio = eb->folios[i]; + bool last; if (!folio_test_dirty(folio)) continue; folio_lock(folio); - btree_clear_folio_dirty(folio); + last = btrfs_meta_folio_clear_and_test_dirty(folio, eb); + if (last) + btree_clear_folio_dirty_tag(folio); folio_unlock(folio); } WARN_ON(atomic_read(&eb->refs) == 0); @@ -4183,100 +3581,87 @@ void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, void set_extent_buffer_dirty(struct extent_buffer *eb) { - int num_folios; bool was_dirty; check_buffer_tree_ref(eb); was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); - num_folios = num_extent_folios(eb); WARN_ON(atomic_read(&eb->refs) == 0); WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)); + WARN_ON(test_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags)); if (!was_dirty) { - bool subpage = eb->fs_info->nodesize < PAGE_SIZE; + bool subpage = btrfs_meta_is_subpage(eb->fs_info); /* * For subpage case, we can have other extent buffers in the - * same page, and in clear_subpage_extent_buffer_dirty() we + * same page, and in clear_extent_buffer_dirty() we * have to clear page dirty without subpage lock held. * This can cause race where our page gets dirty cleared after * we just set it. * - * Thankfully, clear_subpage_extent_buffer_dirty() has locked + * Thankfully, clear_extent_buffer_dirty() has locked * its page for other reasons, we can use page lock to prevent * the above race. */ if (subpage) - lock_page(folio_page(eb->folios[0], 0)); - for (int i = 0; i < num_folios; i++) - btrfs_folio_set_dirty(eb->fs_info, eb->folios[i], - eb->start, eb->len); + folio_lock(eb->folios[0]); + for (int i = 0; i < num_extent_folios(eb); i++) + btrfs_meta_folio_set_dirty(eb->folios[i], eb); + buffer_tree_set_mark(eb, PAGECACHE_TAG_DIRTY); if (subpage) - unlock_page(folio_page(eb->folios[0], 0)); + folio_unlock(eb->folios[0]); percpu_counter_add_batch(&eb->fs_info->dirty_metadata_bytes, eb->len, eb->fs_info->dirty_metadata_batch); } #ifdef CONFIG_BTRFS_DEBUG - for (int i = 0; i < num_folios; i++) + for (int i = 0; i < num_extent_folios(eb); i++) ASSERT(folio_test_dirty(eb->folios[i])); #endif } void clear_extent_buffer_uptodate(struct extent_buffer *eb) { - struct btrfs_fs_info *fs_info = eb->fs_info; - int num_folios = num_extent_folios(eb); clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); - for (int i = 0; i < num_folios; i++) { + for (int i = 0; i < num_extent_folios(eb); i++) { struct folio *folio = eb->folios[i]; if (!folio) continue; - /* - * This is special handling for metadata subpage, as regular - * btrfs_is_subpage() can not handle cloned/dummy metadata. - */ - if (fs_info->nodesize >= PAGE_SIZE) - folio_clear_uptodate(folio); - else - btrfs_subpage_clear_uptodate(fs_info, folio, - eb->start, eb->len); + btrfs_meta_folio_clear_uptodate(folio, eb); } } void set_extent_buffer_uptodate(struct extent_buffer *eb) { - struct btrfs_fs_info *fs_info = eb->fs_info; - int num_folios = num_extent_folios(eb); set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); - for (int i = 0; i < num_folios; i++) { - struct folio *folio = eb->folios[i]; + for (int i = 0; i < num_extent_folios(eb); i++) + btrfs_meta_folio_set_uptodate(eb->folios[i], eb); +} - /* - * This is special handling for metadata subpage, as regular - * btrfs_is_subpage() can not handle cloned/dummy metadata. - */ - if (fs_info->nodesize >= PAGE_SIZE) - folio_mark_uptodate(folio); - else - btrfs_subpage_set_uptodate(fs_info, folio, - eb->start, eb->len); - } +static void clear_extent_buffer_reading(struct extent_buffer *eb) +{ + clear_bit(EXTENT_BUFFER_READING, &eb->bflags); + smp_mb__after_atomic(); + wake_up_bit(&eb->bflags, EXTENT_BUFFER_READING); } static void end_bbio_meta_read(struct btrfs_bio *bbio) { struct extent_buffer *eb = bbio->private; - struct btrfs_fs_info *fs_info = eb->fs_info; bool uptodate = !bbio->bio.bi_status; - struct folio_iter fi; - u32 bio_offset = 0; + + /* + * If the extent buffer is marked UPTODATE before the read operation + * completes, other calls to read_extent_buffer_pages() will return + * early without waiting for the read to finish, causing data races. + */ + WARN_ON(test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)); eb->read_mirror = bbio->mirror_num; @@ -4284,39 +3669,21 @@ static void end_bbio_meta_read(struct btrfs_bio *bbio) btrfs_validate_extent_buffer(eb, &bbio->parent_check) < 0) uptodate = false; - if (uptodate) { + if (uptodate) set_extent_buffer_uptodate(eb); - } else { + else clear_extent_buffer_uptodate(eb); - set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); - } - - bio_for_each_folio_all(fi, &bbio->bio) { - struct folio *folio = fi.folio; - u64 start = eb->start + bio_offset; - u32 len = fi.length; - - if (uptodate) - btrfs_folio_set_uptodate(fs_info, folio, start, len); - else - btrfs_folio_clear_uptodate(fs_info, folio, start, len); - bio_offset += len; - } - - clear_bit(EXTENT_BUFFER_READING, &eb->bflags); - smp_mb__after_atomic(); - wake_up_bit(&eb->bflags, EXTENT_BUFFER_READING); + clear_extent_buffer_reading(eb); free_extent_buffer(eb); bio_put(&bbio->bio); } -int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, - struct btrfs_tree_parent_check *check) +int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num, + const struct btrfs_tree_parent_check *check) { struct btrfs_bio *bbio; - bool ret; if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) return 0; @@ -4331,7 +3698,7 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, /* Someone else is already reading the buffer, just wait for it. */ if (test_and_set_bit(EXTENT_BUFFER_READING, &eb->bflags)) - goto done; + return 0; /* * Between the initial test_bit(EXTENT_BUFFER_UPTODATE) and the above @@ -4340,13 +3707,10 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, * will now be set, and we shouldn't read it in again. */ if (unlikely(test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))) { - clear_bit(EXTENT_BUFFER_READING, &eb->bflags); - smp_mb__after_atomic(); - wake_up_bit(&eb->bflags, EXTENT_BUFFER_READING); + clear_extent_buffer_reading(eb); return 0; } - clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); eb->read_mirror = 0; check_buffer_tree_ref(eb); atomic_inc(&eb->refs); @@ -4358,29 +3722,31 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, bbio->inode = BTRFS_I(eb->fs_info->btree_inode); bbio->file_offset = eb->start; memcpy(&bbio->parent_check, check, sizeof(*check)); - if (eb->fs_info->nodesize < PAGE_SIZE) { - ret = bio_add_folio(&bbio->bio, eb->folios[0], eb->len, - eb->start - folio_pos(eb->folios[0])); - ASSERT(ret); - } else { - int num_folios = num_extent_folios(eb); - - for (int i = 0; i < num_folios; i++) { - struct folio *folio = eb->folios[i]; + for (int i = 0; i < num_extent_folios(eb); i++) { + struct folio *folio = eb->folios[i]; + u64 range_start = max_t(u64, eb->start, folio_pos(folio)); + u32 range_len = min_t(u64, folio_pos(folio) + folio_size(folio), + eb->start + eb->len) - range_start; - ret = bio_add_folio(&bbio->bio, folio, eb->folio_size, 0); - ASSERT(ret); - } + bio_add_folio_nofail(&bbio->bio, folio, range_len, + offset_in_folio(folio, range_start)); } - btrfs_submit_bio(bbio, mirror_num); + btrfs_submit_bbio(bbio, mirror_num); + return 0; +} -done: - if (wait == WAIT_COMPLETE) { - wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_READING, TASK_UNINTERRUPTIBLE); - if (!test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) - return -EIO; - } +int read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num, + const struct btrfs_tree_parent_check *check) +{ + int ret; + + ret = read_extent_buffer_pages_nowait(eb, mirror_num, check); + if (ret < 0) + return ret; + wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_READING, TASK_UNINTERRUPTIBLE); + if (!test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) + return -EIO; return 0; } @@ -4390,7 +3756,7 @@ static bool report_eb_range(const struct extent_buffer *eb, unsigned long start, btrfs_warn(eb->fs_info, "access to eb bytenr %llu len %u out of range start %lu len %lu", eb->start, eb->len, start, len); - WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); + DEBUG_WARN(); return true; } @@ -4552,9 +3918,8 @@ static void assert_eb_folio_uptodate(const struct extent_buffer *eb, int i) if (test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) return; - if (fs_info->nodesize < PAGE_SIZE) { - struct folio *folio = eb->folios[0]; - + if (btrfs_meta_is_subpage(fs_info)) { + folio = eb->folios[0]; ASSERT(i == 0); if (WARN_ON(!btrfs_subpage_test_uptodate(fs_info, folio, eb->start, eb->len))) @@ -4572,7 +3937,7 @@ static void __write_extent_buffer(const struct extent_buffer *eb, size_t cur; size_t offset; char *kaddr; - char *src = (char *)srcv; + const char *src = (const char *)srcv; unsigned long i = get_eb_folio_index(eb, start); /* For unmapped (dummy) ebs, no need to check their uptodate status. */ const bool check_uptodate = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); @@ -4927,71 +4292,17 @@ void memmove_extent_buffer(const struct extent_buffer *dst, } } -#define GANG_LOOKUP_SIZE 16 -static struct extent_buffer *get_next_extent_buffer( - struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr) -{ - struct extent_buffer *gang[GANG_LOOKUP_SIZE]; - struct extent_buffer *found = NULL; - u64 page_start = page_offset(page); - u64 cur = page_start; - - ASSERT(in_range(bytenr, page_start, PAGE_SIZE)); - lockdep_assert_held(&fs_info->buffer_lock); - - while (cur < page_start + PAGE_SIZE) { - int ret; - int i; - - ret = radix_tree_gang_lookup(&fs_info->buffer_radix, - (void **)gang, cur >> fs_info->sectorsize_bits, - min_t(unsigned int, GANG_LOOKUP_SIZE, - PAGE_SIZE / fs_info->nodesize)); - if (ret == 0) - goto out; - for (i = 0; i < ret; i++) { - /* Already beyond page end */ - if (gang[i]->start >= page_start + PAGE_SIZE) - goto out; - /* Found one */ - if (gang[i]->start >= bytenr) { - found = gang[i]; - goto out; - } - } - cur = gang[ret - 1]->start + gang[ret - 1]->len; - } -out: - return found; -} - -static int try_release_subpage_extent_buffer(struct page *page) +static int try_release_subpage_extent_buffer(struct folio *folio) { - struct btrfs_fs_info *fs_info = page_to_fs_info(page); - u64 cur = page_offset(page); - const u64 end = page_offset(page) + PAGE_SIZE; + struct btrfs_fs_info *fs_info = folio_to_fs_info(folio); + struct extent_buffer *eb; + unsigned long start = (folio_pos(folio) >> fs_info->sectorsize_bits); + unsigned long index = start; + unsigned long end = index + (PAGE_SIZE >> fs_info->sectorsize_bits) - 1; int ret; - while (cur < end) { - struct extent_buffer *eb = NULL; - - /* - * Unlike try_release_extent_buffer() which uses folio private - * to grab buffer, for subpage case we rely on radix tree, thus - * we need to ensure radix tree consistency. - * - * We also want an atomic snapshot of the radix tree, thus go - * with spinlock rather than RCU. - */ - spin_lock(&fs_info->buffer_lock); - eb = get_next_extent_buffer(fs_info, page, cur); - if (!eb) { - /* No more eb in the page range after or at cur */ - spin_unlock(&fs_info->buffer_lock); - break; - } - cur = eb->start + eb->len; - + xa_lock_irq(&fs_info->buffer_tree); + xa_for_each_range(&fs_info->buffer_tree, index, eb, start, end) { /* * The same as try_release_extent_buffer(), to ensure the eb * won't disappear out from under us. @@ -4999,10 +4310,9 @@ static int try_release_subpage_extent_buffer(struct page *page) spin_lock(&eb->refs_lock); if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) { spin_unlock(&eb->refs_lock); - spin_unlock(&fs_info->buffer_lock); - break; + continue; } - spin_unlock(&fs_info->buffer_lock); + xa_unlock_irq(&fs_info->buffer_tree); /* * If tree ref isn't set then we know the ref on this eb is a @@ -5020,36 +4330,38 @@ static int try_release_subpage_extent_buffer(struct page *page) * release_extent_buffer() will release the refs_lock. */ release_extent_buffer(eb); + xa_lock_irq(&fs_info->buffer_tree); } + xa_unlock_irq(&fs_info->buffer_tree); + /* * Finally to check if we have cleared folio private, as if we have * released all ebs in the page, the folio private should be cleared now. */ - spin_lock(&page->mapping->i_private_lock); - if (!folio_test_private(page_folio(page))) + spin_lock(&folio->mapping->i_private_lock); + if (!folio_test_private(folio)) ret = 1; else ret = 0; - spin_unlock(&page->mapping->i_private_lock); + spin_unlock(&folio->mapping->i_private_lock); return ret; } -int try_release_extent_buffer(struct page *page) +int try_release_extent_buffer(struct folio *folio) { - struct folio *folio = page_folio(page); struct extent_buffer *eb; - if (page_to_fs_info(page)->nodesize < PAGE_SIZE) - return try_release_subpage_extent_buffer(page); + if (btrfs_meta_is_subpage(folio_to_fs_info(folio))) + return try_release_subpage_extent_buffer(folio); /* * We need to make sure nobody is changing folio private, as we rely on * folio private as the pointer to extent buffer. */ - spin_lock(&page->mapping->i_private_lock); + spin_lock(&folio->mapping->i_private_lock); if (!folio_test_private(folio)) { - spin_unlock(&page->mapping->i_private_lock); + spin_unlock(&folio->mapping->i_private_lock); return 1; } @@ -5064,10 +4376,10 @@ int try_release_extent_buffer(struct page *page) spin_lock(&eb->refs_lock); if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) { spin_unlock(&eb->refs_lock); - spin_unlock(&page->mapping->i_private_lock); + spin_unlock(&folio->mapping->i_private_lock); return 0; } - spin_unlock(&page->mapping->i_private_lock); + spin_unlock(&folio->mapping->i_private_lock); /* * If tree ref isn't set then we know the ref on this eb is a real ref, @@ -5098,7 +4410,6 @@ void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr, u64 owner_root, u64 gen, int level) { struct btrfs_tree_parent_check check = { - .has_first_key = 0, .level = level, .transid = gen }; @@ -5114,7 +4425,7 @@ void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, return; } - ret = read_extent_buffer_pages(eb, WAIT_NONE, 0, &check); + ret = read_extent_buffer_pages_nowait(eb, 0, &check); if (ret < 0) free_extent_buffer_stale(eb); else |