From fcb8a66d83c44f111d93d51a6f94b13819ca061e Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 2 Oct 2024 08:02:13 -0700 Subject: [PATCH] iomap: constrain the file range passed to iomap_file_unshare [ Upstream commit a311a08a4237241fb5b9d219d3e33346de6e83e0 ] File contents can only be shared (i.e. reflinked) below EOF, so it makes no sense to try to unshare ranges beyond EOF. Constrain the file range parameters here so that we don't have to do that in the callers. Fixes: 5f4e5752a8a3 ("fs: add iomap_file_dirty") Signed-off-by: Darrick J. Wong Link: https://lore.kernel.org/r/20241002150213.GC21853@frogsfrogsfrogs Reviewed-by: Christoph Hellwig Reviewed-by: Brian Foster Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/dax.c | 6 +++++- fs/iomap/buffered-io.c | 6 +++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 626745bc1ad8..7ecad1a28a89 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1262,11 +1262,15 @@ int dax_file_unshare(struct inode *inode, loff_t pos, loff_t len, struct iomap_iter iter = { .inode = inode, .pos = pos, - .len = len, .flags = IOMAP_WRITE | IOMAP_UNSHARE | IOMAP_DAX, }; + loff_t size = i_size_read(inode); int ret; + if (pos < 0 || pos >= size) + return 0; + + iter.len = min(len, size - pos); while ((ret = iomap_iter(&iter, ops)) > 0) iter.processed = dax_unshare_iter(&iter); return ret; diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 0f7dabc6c764..98617f00101d 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1126,11 +1126,15 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, struct iomap_iter iter = { .inode = inode, .pos = pos, - .len = len, .flags = IOMAP_WRITE | IOMAP_UNSHARE, }; + loff_t size = i_size_read(inode); int ret; + if (pos < 0 || pos >= size) + return 0; + + iter.len = min(len, size - pos); while ((ret = iomap_iter(&iter, ops)) > 0) iter.processed = iomap_unshare_iter(&iter); return ret;