Merge tag 'for-6.12-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This brings mostly refactoring, cleanups, minor performance
  optimizations and usual fixes. The folio API conversions are most
  noticeable.

  There's one less visible change that could have a high impact. The
  extent lock scope for read is reduced, not held for the entire
  operation. In the buffered read case it's left to page or inode lock,
  some direct io read synchronization is still needed.

  This used to prevent deadlocks induced by page faults during direct
  io, so there was a 4K limitation on the requests, e.g. for io_uring.
  In the future this will allow smoother integration with iomap where
  the extent read lock was a major obstacle.

  User visible changes:

   - the FSTRIM ioctl updates the processed range even after an error or
     interruption

   - cleaner thread is woken up in SYNC ioctl instead of waking the
     transaction thread that can take some delay before waking up the
     cleaner, this can speed up cleaning of deleted subvolumes

   - print an error message when opening a device fail, e.g. when it's
     unexpectedly read-only

  Core changes:

   - improved extent map handling in various ways (locking, iteration, ...)

   - new assertions and locking annotations

   - raid-stripe-tree locking fixes

   - use xarray for tracking dirty qgroup extents, switched from rb-tree

   - turn the subpage test to compile-time condition if possible (e.g.
     on x86_64 with 4K pages), this allows to skip a lot of ifs and
     remove dead code

   - more preparatory work for compression in subpage mode

  Cleanups and refactoring

   - folio API conversions, many simple cases where page is passed so
     switch it to folios

   - more subpage code refactoring, update page state bitmap processing

   - introduce auto free for btrfs_path structure, use for the simple
     cases"

* tag 'for-6.12-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (110 commits)
  btrfs: only unlock the to-be-submitted ranges inside a folio
  btrfs: merge btrfs_folio_unlock_writer() into btrfs_folio_end_writer_lock()
  btrfs: BTRFS_PATH_AUTO_FREE in orphan.c
  btrfs: use btrfs_path auto free in zoned.c
  btrfs: DEFINE_FREE for struct btrfs_path
  btrfs: remove btrfs_folio_end_all_writers()
  btrfs: constify more pointer parameters
  btrfs: rework BTRFS_I as macro to preserve parameter const
  btrfs: add and use helper to verify the calling task has locked the inode
  btrfs: always update fstrim_range on failure in FITRIM ioctl
  btrfs: convert copy_inline_to_page() to use folio
  btrfs: convert btrfs_decompress() to take a folio
  btrfs: convert zstd_decompress() to take a folio
  btrfs: convert lzo_decompress() to take a folio
  btrfs: convert zlib_decompress() to take a folio
  btrfs: convert try_release_extent_mapping() to take a folio
  btrfs: convert try_release_extent_state() to take a folio
  btrfs: convert submit_eb_page() to take a folio
  btrfs: convert submit_eb_subpage() to take a folio
  btrfs: convert read_key_bytes() to take a folio
  ...

1 files changed, 124 insertions, 153 deletions

diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c
index 8ddd5fcbeb93..fe4d719d506b 100644
--- a/fs/btrfs/subpage.c
+++ b/fs/btrfs/subpage.c
@@ -64,6 +64,7 @@
  *   This means a slightly higher tree locking latency.
  */
 
+#if PAGE_SIZE > SZ_4K
 bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, struct address_space *mapping)
 {
 	if (fs_info->sectorsize >= PAGE_SIZE)
@@ -85,37 +86,7 @@ bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, struct address_space
 		return true;
 	return false;
 }
-
-void btrfs_init_subpage_info(struct btrfs_subpage_info *subpage_info, u32 sectorsize)
-{
-	unsigned int cur = 0;
-	unsigned int nr_bits;
-
-	ASSERT(IS_ALIGNED(PAGE_SIZE, sectorsize));
-
-	nr_bits = PAGE_SIZE / sectorsize;
-	subpage_info->bitmap_nr_bits = nr_bits;
-
-	subpage_info->uptodate_offset = cur;
-	cur += nr_bits;
-
-	subpage_info->dirty_offset = cur;
-	cur += nr_bits;
-
-	subpage_info->writeback_offset = cur;
-	cur += nr_bits;
-
-	subpage_info->ordered_offset = cur;
-	cur += nr_bits;
-
-	subpage_info->checked_offset = cur;
-	cur += nr_bits;
-
-	subpage_info->locked_offset = cur;
-	cur += nr_bits;
-
-	subpage_info->total_nr_bits = cur;
-}
+#endif
 
 int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
 			 struct folio *folio, enum btrfs_subpage_type type)
@@ -163,7 +134,7 @@ struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
 	ASSERT(fs_info->sectorsize < PAGE_SIZE);
 
 	real_size = struct_size(ret, bitmaps,
-			BITS_TO_LONGS(fs_info->subpage_info->total_nr_bits));
+			BITS_TO_LONGS(btrfs_bitmap_nr_max * fs_info->sectors_per_page));
 	ret = kzalloc(real_size, GFP_NOFS);
 	if (!ret)
 		return ERR_PTR(-ENOMEM);
@@ -246,7 +217,7 @@ static void btrfs_subpage_assert(const struct btrfs_fs_info *fs_info,
 									\
 	btrfs_subpage_assert(fs_info, folio, start, len);		\
 	__start_bit = offset_in_page(start) >> fs_info->sectorsize_bits; \
-	__start_bit += fs_info->subpage_info->name##_offset;		\
+	__start_bit += fs_info->sectors_per_page * btrfs_bitmap_nr_##name; \
 	__start_bit;							\
 })
 
@@ -351,6 +322,8 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf
 	const int start_bit = subpage_calc_start_bit(fs_info, folio, locked, start, len);
 	const int nbits = (len >> fs_info->sectorsize_bits);
 	unsigned long flags;
+	unsigned int cleared = 0;
+	int bit = start_bit;
 	bool last;
 
 	btrfs_subpage_assert(fs_info, folio, start, len);
@@ -368,11 +341,12 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf
 		return true;
 	}
 
-	ASSERT(atomic_read(&subpage->writers) >= nbits);
-	/* The target range should have been locked. */
-	ASSERT(bitmap_test_range_all_set(subpage->bitmaps, start_bit, nbits));
-	bitmap_clear(subpage->bitmaps, start_bit, nbits);
-	last = atomic_sub_and_test(nbits, &subpage->writers);
+	for_each_set_bit_from(bit, subpage->bitmaps, start_bit + nbits) {
+		clear_bit(bit, subpage->bitmaps);
+		cleared++;
+	}
+	ASSERT(atomic_read(&subpage->writers) >= cleared);
+	last = atomic_sub_and_test(cleared, &subpage->writers);
 	spin_unlock_irqrestore(&subpage->lock, flags);
 	return last;
 }
@@ -404,27 +378,94 @@ int btrfs_folio_start_writer_lock(const struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
+/*
+ * Handle different locked folios:
+ *
+ * - Non-subpage folio
+ *   Just unlock it.
+ *
+ * - folio locked but without any subpage locked
+ *   This happens either before writepage_delalloc() or the delalloc range is
+ *   already handled by previous folio.
+ *   We can simple unlock it.
+ *
+ * - folio locked with subpage range locked.
+ *   We go through the locked sectors inside the range and clear their locked
+ *   bitmap, reduce the writer lock number, and unlock the page if that's
+ *   the last locked range.
+ */
 void btrfs_folio_end_writer_lock(const struct btrfs_fs_info *fs_info,
 				 struct folio *folio, u64 start, u32 len)
 {
+	struct btrfs_subpage *subpage = folio_get_private(folio);
+
+	ASSERT(folio_test_locked(folio));
+
 	if (unlikely(!fs_info) || !btrfs_is_subpage(fs_info, folio->mapping)) {
 		folio_unlock(folio);
 		return;
 	}
+
+	/*
+	 * For subpage case, there are two types of locked page.  With or
+	 * without writers number.
+	 *
+	 * Since we own the page lock, no one else could touch subpage::writers
+	 * and we are safe to do several atomic operations without spinlock.
+	 */
+	if (atomic_read(&subpage->writers) == 0) {
+		/* No writers, locked by plain lock_page(). */
+		folio_unlock(folio);
+		return;
+	}
+
 	btrfs_subpage_clamp_range(folio, &start, &len);
 	if (btrfs_subpage_end_and_test_writer(fs_info, folio, start, len))
 		folio_unlock(folio);
 }
 
+void btrfs_folio_end_writer_lock_bitmap(const struct btrfs_fs_info *fs_info,
+					struct folio *folio, unsigned long bitmap)
+{
+	struct btrfs_subpage *subpage = folio_get_private(folio);
+	const int start_bit = fs_info->sectors_per_page * btrfs_bitmap_nr_locked;
+	unsigned long flags;
+	bool last = false;
+	int cleared = 0;
+	int bit;
+
+	if (unlikely(!fs_info) || !btrfs_is_subpage(fs_info, folio->mapping)) {
+		folio_unlock(folio);
+		return;
+	}
+
+	if (atomic_read(&subpage->writers) == 0) {
+		/* No writers, locked by plain lock_page(). */
+		folio_unlock(folio);
+		return;
+	}
+
+	spin_lock_irqsave(&subpage->lock, flags);
+	for_each_set_bit(bit, &bitmap, fs_info->sectors_per_page) {
+		if (test_and_clear_bit(bit + start_bit, subpage->bitmaps))
+			cleared++;
+	}
+	ASSERT(atomic_read(&subpage->writers) >= cleared);
+	last = atomic_sub_and_test(cleared, &subpage->writers);
+	spin_unlock_irqrestore(&subpage->lock, flags);
+	if (last)
+		folio_unlock(folio);
+}
+
 #define subpage_test_bitmap_all_set(fs_info, subpage, name)		\
 	bitmap_test_range_all_set(subpage->bitmaps,			\
-			fs_info->subpage_info->name##_offset,		\
-			fs_info->subpage_info->bitmap_nr_bits)
+			fs_info->sectors_per_page * btrfs_bitmap_nr_##name, \
+			fs_info->sectors_per_page)
 
 #define subpage_test_bitmap_all_zero(fs_info, subpage, name)		\
 	bitmap_test_range_all_zero(subpage->bitmaps,			\
-			fs_info->subpage_info->name##_offset,		\
-			fs_info->subpage_info->bitmap_nr_bits)
+			fs_info->sectors_per_page * btrfs_bitmap_nr_##name, \
+			fs_info->sectors_per_page)
 
 void btrfs_subpage_set_uptodate(const struct btrfs_fs_info *fs_info,
 				struct folio *folio, u64 start, u32 len)
@@ -729,53 +770,6 @@ void btrfs_folio_assert_not_dirty(const struct btrfs_fs_info *fs_info,
 }
 
 /*
- * Handle different locked pages with different page sizes:
- *
- * - Page locked by plain lock_page()
- *   It should not have any subpage::writers count.
- *   Can be unlocked by unlock_page().
- *   This is the most common locked page for __extent_writepage() called
- *   inside extent_write_cache_pages().
- *   Rarer cases include the @locked_page from extent_write_locked_range().
- *
- * - Page locked by lock_delalloc_pages()
- *   There is only one caller, all pages except @locked_page for
- *   extent_write_locked_range().
- *   In this case, we have to call subpage helper to handle the case.
- */
-void btrfs_folio_unlock_writer(struct btrfs_fs_info *fs_info,
-			       struct folio *folio, u64 start, u32 len)
-{
-	struct btrfs_subpage *subpage;
-
-	ASSERT(folio_test_locked(folio));
-	/* For non-subpage case, we just unlock the page */
-	if (!btrfs_is_subpage(fs_info, folio->mapping)) {
-		folio_unlock(folio);
-		return;
-	}
-
-	ASSERT(folio_test_private(folio) && folio_get_private(folio));
-	subpage = folio_get_private(folio);
-
-	/*
-	 * For subpage case, there are two types of locked page.  With or
-	 * without writers number.
-	 *
-	 * Since we own the page lock, no one else could touch subpage::writers
-	 * and we are safe to do several atomic operations without spinlock.
-	 */
-	if (atomic_read(&subpage->writers) == 0) {
-		/* No writers, locked by plain lock_page() */
-		folio_unlock(folio);
-		return;
-	}
-
-	/* Have writers, use proper subpage helper to end it */
-	btrfs_folio_end_writer_lock(fs_info, folio, start, len);
-}
-
-/*
  * This is for folio already locked by plain lock_page()/folio_lock(), which
  * doesn't have any subpage awareness.
  *
@@ -803,7 +797,7 @@ void btrfs_folio_set_writer_lock(const struct btrfs_fs_info *fs_info,
 	ASSERT(bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits));
 	bitmap_set(subpage->bitmaps, start_bit, nbits);
 	ret = atomic_add_return(nbits, &subpage->writers);
-	ASSERT(ret <= fs_info->subpage_info->bitmap_nr_bits);
+	ASSERT(ret <= fs_info->sectors_per_page);
 	spin_unlock_irqrestore(&subpage->lock, flags);
 }
 
@@ -819,14 +813,13 @@ bool btrfs_subpage_find_writer_locked(const struct btrfs_fs_info *fs_info,
 				      struct folio *folio, u64 search_start,
 				      u64 *found_start_ret, u32 *found_len_ret)
 {
-	struct btrfs_subpage_info *subpage_info = fs_info->subpage_info;
 	struct btrfs_subpage *subpage = folio_get_private(folio);
+	const u32 sectors_per_page = fs_info->sectors_per_page;
 	const unsigned int len = PAGE_SIZE - offset_in_page(search_start);
 	const unsigned int start_bit = subpage_calc_start_bit(fs_info, folio,
 						locked, search_start, len);
-	const unsigned int locked_bitmap_start = subpage_info->locked_offset;
-	const unsigned int locked_bitmap_end = locked_bitmap_start +
-					       subpage_info->bitmap_nr_bits;
+	const unsigned int locked_bitmap_start = sectors_per_page * btrfs_bitmap_nr_locked;
+	const unsigned int locked_bitmap_end = locked_bitmap_start + sectors_per_page;
 	unsigned long flags;
 	int first_zero;
 	int first_set;
@@ -855,59 +848,21 @@ out:
 	return found;
 }
 
-/*
- * Unlike btrfs_folio_end_writer_lock() which unlocks a specified subpage range,
- * this ends all writer locked ranges of a page.
- *
- * This is for the locked page of __extent_writepage(), as the locked page
- * can contain several locked subpage ranges.
- */
-void btrfs_folio_end_all_writers(const struct btrfs_fs_info *fs_info, struct folio *folio)
-{
-	struct btrfs_subpage *subpage = folio_get_private(folio);
-	u64 folio_start = folio_pos(folio);
-	u64 cur = folio_start;
-
-	ASSERT(folio_test_locked(folio));
-	if (!btrfs_is_subpage(fs_info, folio->mapping)) {
-		folio_unlock(folio);
-		return;
-	}
-
-	/* The page has no new delalloc range locked on it. Just plain unlock. */
-	if (atomic_read(&subpage->writers) == 0) {
-		folio_unlock(folio);
-		return;
-	}
-	while (cur < folio_start + PAGE_SIZE) {
-		u64 found_start;
-		u32 found_len;
-		bool found;
-		bool last;
-
-		found = btrfs_subpage_find_writer_locked(fs_info, folio, cur,
-							 &found_start, &found_len);
-		if (!found)
-			break;
-		last = btrfs_subpage_end_and_test_writer(fs_info, folio,
-							 found_start, found_len);
-		if (last) {
-			folio_unlock(folio);
-			break;
-		}
-		cur = found_start + found_len;
-	}
+#define GET_SUBPAGE_BITMAP(subpage, fs_info, name, dst)			\
+{									\
+	const int sectors_per_page = fs_info->sectors_per_page;		\
+									\
+	ASSERT(sectors_per_page < BITS_PER_LONG);			\
+	*dst = bitmap_read(subpage->bitmaps,				\
+			   sectors_per_page * btrfs_bitmap_nr_##name,	\
+			   sectors_per_page);				\
 }
 
-#define GET_SUBPAGE_BITMAP(subpage, subpage_info, name, dst)		\
-	bitmap_cut(dst, subpage->bitmaps, 0,				\
-		   subpage_info->name##_offset, subpage_info->bitmap_nr_bits)
-
 void __cold btrfs_subpage_dump_bitmap(const struct btrfs_fs_info *fs_info,
 				      struct folio *folio, u64 start, u32 len)
 {
-	struct btrfs_subpage_info *subpage_info = fs_info->subpage_info;
 	struct btrfs_subpage *subpage;
+	const u32 sectors_per_page = fs_info->sectors_per_page;
 	unsigned long uptodate_bitmap;
 	unsigned long dirty_bitmap;
 	unsigned long writeback_bitmap;
@@ -916,25 +871,41 @@ void __cold btrfs_subpage_dump_bitmap(const struct btrfs_fs_info *fs_info,
 	unsigned long flags;
 
 	ASSERT(folio_test_private(folio) && folio_get_private(folio));
-	ASSERT(subpage_info);
+	ASSERT(sectors_per_page > 1);
 	subpage = folio_get_private(folio);
 
 	spin_lock_irqsave(&subpage->lock, flags);
-	GET_SUBPAGE_BITMAP(subpage, subpage_info, uptodate, &uptodate_bitmap);
-	GET_SUBPAGE_BITMAP(subpage, subpage_info, dirty, &dirty_bitmap);
-	GET_SUBPAGE_BITMAP(subpage, subpage_info, writeback, &writeback_bitmap);
-	GET_SUBPAGE_BITMAP(subpage, subpage_info, ordered, &ordered_bitmap);
-	GET_SUBPAGE_BITMAP(subpage, subpage_info, checked, &checked_bitmap);
-	GET_SUBPAGE_BITMAP(subpage, subpage_info, locked, &checked_bitmap);
+	GET_SUBPAGE_BITMAP(subpage, fs_info, uptodate, &uptodate_bitmap);
+	GET_SUBPAGE_BITMAP(subpage, fs_info, dirty, &dirty_bitmap);
+	GET_SUBPAGE_BITMAP(subpage, fs_info, writeback, &writeback_bitmap);
+	GET_SUBPAGE_BITMAP(subpage, fs_info, ordered, &ordered_bitmap);
+	GET_SUBPAGE_BITMAP(subpage, fs_info, checked, &checked_bitmap);
+	GET_SUBPAGE_BITMAP(subpage, fs_info, locked, &checked_bitmap);
 	spin_unlock_irqrestore(&subpage->lock, flags);
 
 	dump_page(folio_page(folio, 0), "btrfs subpage dump");
 	btrfs_warn(fs_info,
 "start=%llu len=%u page=%llu, bitmaps uptodate=%*pbl dirty=%*pbl writeback=%*pbl ordered=%*pbl checked=%*pbl",
 		    start, len, folio_pos(folio),
-		    subpage_info->bitmap_nr_bits, &uptodate_bitmap,
-		    subpage_info->bitmap_nr_bits, &dirty_bitmap,
-		    subpage_info->bitmap_nr_bits, &writeback_bitmap,
-		    subpage_info->bitmap_nr_bits, &ordered_bitmap,
-		    subpage_info->bitmap_nr_bits, &checked_bitmap);
+		    sectors_per_page, &uptodate_bitmap,
+		    sectors_per_page, &dirty_bitmap,
+		    sectors_per_page, &writeback_bitmap,
+		    sectors_per_page, &ordered_bitmap,
+		    sectors_per_page, &checked_bitmap);
+}
+
+void btrfs_get_subpage_dirty_bitmap(struct btrfs_fs_info *fs_info,
+				    struct folio *folio,
+				    unsigned long *ret_bitmap)
+{
+	struct btrfs_subpage *subpage;
+	unsigned long flags;
+
+	ASSERT(folio_test_private(folio) && folio_get_private(folio));
+	ASSERT(fs_info->sectors_per_page > 1);
+	subpage = folio_get_private(folio);
+
+	spin_lock_irqsave(&subpage->lock, flags);
+	GET_SUBPAGE_BITMAP(subpage, fs_info, dirty, ret_bitmap);
+	spin_unlock_irqrestore(&subpage->lock, flags);
 }