5.4-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
[ Upstream commit 691a41d8da4b34fe72f09393505f55f28a8f34ec ]
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") Cc: stable@vger.kernel.org Suggested-by: Dave Chinner david@fromorbit.com cc: Xiaoli Feng fengxiaoli0714@gmail.com cc: Shyam Prasad N nspmangalore@gmail.com cc: Rohith Surabattula rohiths.msft@gmail.com cc: Jeff Layton jlayton@kernel.org cc: Darrick Wong darrick.wong@oracle.com cc: fstests@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/3876191.1701555260@warthog.procyon.org.uk/ Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/cifsfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 917441e3018ad..12f632287d161 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -1079,7 +1079,9 @@ 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");