Deduplication isn't supported on cifs, but cifs doesn't reject it, instead
treating it as extent duplication/cloning. This can cause generic/304 to go
silly and run for hours on end.
Fix cifs to indicate EOPNOTSUPP if REMAP_FILE_DEDUP is set in
->remap_file_range().
Note that it's unclear whether or not commit b073a08016a1 is meant to cause
cifs to return an error if REMAP_FILE_DEDUP.
Fixes: b073a08016a1 ("cifs: fix that return -EINVAL when do dedupe operation")
Suggested-by: Dave Chinner <david@xxxxxxxxxxxxx>
cc: Steve French <sfrench@xxxxxxxxx>
cc: Xiaoli Feng <fengxiaoli0714@xxxxxxxxx>
cc: Shyam Prasad N <nspmangalore@xxxxxxxxx>
cc: Rohith Surabattula <rohiths.msft@xxxxxxxxx>
cc: Jeff Layton <jlayton@xxxxxxxxxx>
cc: Darrick Wong <darrick.wong@xxxxxxxxxx>
cc: fstests@xxxxxxxxxxxxxxx
cc: linux-cifs@xxxxxxxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/3876191.1701555260@xxxxxxxxxxxxxxxxxxxxxx/
---
fs/smb/client/cifsfs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index 4d8927b57776..96a65cf9b5ec 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -1276,7 +1276,9 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off,
unsigned int xid;
int rc;
- if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
+ if (remap_flags & REMAP_FILE_DEDUP)
+ return -EOPNOTSUPP;
+ if (remap_flags & ~REMAP_FILE_ADVISORY)
return -EINVAL;
cifs_dbg(FYI, "clone range\n");
