From 24be4091b8018c5c754e86b740fddd8fd29b3998 Mon Sep 17 00:00:00 2001 From: "Ritesh Harjani (IBM)" Date: Tue, 7 May 2024 14:25:42 +0530 Subject: [PATCH] iomap: Fix iomap_adjust_read_range for plen calculation [ Upstream commit f5ceb1bbc98c69536d4673a97315e8427e67de1b ] If the extent spans the block that contains i_size, we need to handle both halves separately so that we properly zero data in the page cache for blocks that are entirely outside of i_size. But this is needed only when i_size is within the current folio under processing. "orig_pos + length > isize" can be true for all folios if the mapped extent length is greater than the folio size. That is making plen to break for every folio instead of only the last folio. So use orig_plen for checking if "orig_pos + orig_plen > isize". Signed-off-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/a32e5f9a4fcfdb99077300c4020ed7ae61d6e0f9.1715067055.git.ritesh.list@gmail.com Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Reviewed-by: Jan Kara cc: Ojaswin Mujoo Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/iomap/buffered-io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 129a85633797..975fd88c1f0f 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -201,6 +201,7 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio, unsigned block_size = (1 << block_bits); size_t poff = offset_in_folio(folio, *pos); size_t plen = min_t(loff_t, folio_size(folio) - poff, length); + size_t orig_plen = plen; unsigned first = poff >> block_bits; unsigned last = (poff + plen - 1) >> block_bits; @@ -237,7 +238,7 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio, * handle both halves separately so that we properly zero data in the * page cache for blocks that are entirely outside of i_size. */ - if (orig_pos <= isize && orig_pos + length > isize) { + if (orig_pos <= isize && orig_pos + orig_plen > isize) { unsigned end = offset_in_folio(folio, isize - 1) >> block_bits; if (first <= end && last > end)