6.6-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 3380b43cb6bbb..d48b4fc7a4838 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 975fd88c1f0f4..5371b16341fff 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1316,11 +1316,15 @@ 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
