6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Darrick J. Wong <djwong@xxxxxxxxxx>
[ 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 <djwong@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241002150213.GC21853@frogsfrogsfrogs
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 becb4a6920c6a..c62acd2812f8d 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1305,11 +1305,15 @@ 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 f420c53d86acc..389de94715b53 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1382,11 +1382,15 @@ 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;
--
2.43.0
