From d53b2d49a8e2500deeb0f9373094938ac43d9495 Mon Sep 17 00:00:00 2001 From: Gou Hao Date: Thu, 10 Apr 2025 15:12:36 +0800 Subject: [PATCH] iomap: skip unnecessary ifs_block_is_uptodate check [ 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 Link: https://lore.kernel.org/20250410071236.16017-1-gouhao@uniontech.com Reviewed-by: "Darrick J. Wong" Reviewed-by: Christoph Hellwig Suggested-by: Christoph Hellwig Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- 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 1bad460275eb..d4b990938399 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;