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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-04-28 23:59:15 -0400
committerMatthew Wilcox (Oracle) <willy@infradead.org>2022-05-08 14:45:57 -0400
commit6c2ae0d5db57d772a11f2d7399da5e22f94767d6 (patch)
treee8524508b12038ee8c57452b4bcb4a15bb314a82 /fs/buffer.c
parent2ebdd1df316636c2faf25a1780e12553adf09cf7 (diff)
buffer: Rewrite nobh_truncate_page() to use folios
- Calculate iblock directly instead of using a while loop - Move has_buffers to the end to remove a backwards jump - Use __filemap_get_folio() instead of grab_cache_page(), which removes a spurious FGP_ACCESSED flag. - Eliminate length and pos variables - Use folio APIs where they exist Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/buffer.c')
-rw-r--r--fs/buffer.c64
1 files changed, 27 insertions, 37 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index fb4df259c92d..9737e0dbe3ec 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2791,44 +2791,28 @@ int nobh_truncate_page(struct address_space *mapping,
loff_t from, get_block_t *get_block)
{
pgoff_t index = from >> PAGE_SHIFT;
- unsigned offset = from & (PAGE_SIZE-1);
- unsigned blocksize;
- sector_t iblock;
- unsigned length, pos;
struct inode *inode = mapping->host;
- struct page *page;
+ unsigned blocksize = i_blocksize(inode);
+ struct folio *folio;
struct buffer_head map_bh;
+ size_t offset;
+ sector_t iblock;
int err;
- blocksize = i_blocksize(inode);
- length = offset & (blocksize - 1);
-
/* Block boundary? Nothing to do */
- if (!length)
+ if (!(from & (blocksize - 1)))
return 0;
- length = blocksize - length;
- iblock = (sector_t)index << (PAGE_SHIFT - inode->i_blkbits);
-
- page = grab_cache_page(mapping, index);
+ folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_CREAT,
+ mapping_gfp_mask(mapping));
err = -ENOMEM;
- if (!page)
+ if (!folio)
goto out;
- if (page_has_buffers(page)) {
-has_buffers:
- unlock_page(page);
- put_page(page);
- return block_truncate_page(mapping, from, get_block);
- }
-
- /* Find the buffer that contains "offset" */
- pos = blocksize;
- while (offset >= pos) {
- iblock++;
- pos += blocksize;
- }
+ if (folio_buffers(folio))
+ goto has_buffers;
+ iblock = from >> inode->i_blkbits;
map_bh.b_size = blocksize;
map_bh.b_state = 0;
err = get_block(inode, iblock, &map_bh, 0);
@@ -2839,29 +2823,35 @@ has_buffers:
goto unlock;
/* Ok, it's mapped. Make sure it's up-to-date */
- if (!PageUptodate(page)) {
- err = mapping->a_ops->readpage(NULL, page);
+ if (!folio_test_uptodate(folio)) {
+ err = mapping->a_ops->readpage(NULL, &folio->page);
if (err) {
- put_page(page);
+ folio_put(folio);
goto out;
}
- lock_page(page);
- if (!PageUptodate(page)) {
+ folio_lock(folio);
+ if (!folio_test_uptodate(folio)) {
err = -EIO;
goto unlock;
}
- if (page_has_buffers(page))
+ if (folio_buffers(folio))
goto has_buffers;
}
- zero_user(page, offset, length);
- set_page_dirty(page);
+ offset = offset_in_folio(folio, from);
+ folio_zero_segment(folio, offset, round_up(offset, blocksize));
+ folio_mark_dirty(folio);
err = 0;
unlock:
- unlock_page(page);
- put_page(page);
+ folio_unlock(folio);
+ folio_put(folio);
out:
return err;
+
+has_buffers:
+ folio_unlock(folio);
+ folio_put(folio);
+ return block_truncate_page(mapping, from, get_block);
}
EXPORT_SYMBOL(nobh_truncate_page);