From: Gou Hao gouhao@uniontech.com
[ Upstream commit 8e3c15ee0d292c413c66fe10201d1b035a0bea72 ]
In iomap_adjust_read_range, i is either the first !uptodate block, or it is past last for the second loop looking for trailing uptodate blocks. Assuming there's no overflow (there's no combination of huge folios and tiny blksize) then yeah, there is no point in retesting that the same block pointed to by i is uptodate since we hold the folio lock so nobody else could have set it uptodate.
Signed-off-by: Gou Hao gouhao@uniontech.com Link: https://lore.kernel.org/20250410071236.16017-1-gouhao@uniontech.com Reviewed-by: "Darrick J. Wong" djwong@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Suggested-by: Christoph Hellwig hch@infradead.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/iomap/buffered-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 1bad460275ebe..d4b990938399c 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -263,7 +263,7 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio, }
/* truncate len if we find any trailing uptodate block(s) */ - for ( ; i <= last; i++) { + while (++i <= last) { if (ifs_block_is_uptodate(ifs, i)) { plen -= (last - i + 1) * block_size; last = i - 1;