[ Upstream commit 3f965021c8 ]
Since, well, forever, the Linux NFS server's nfsd_commit() function
has returned nfserr_inval when the passed-in byte range arguments
were non-sensical.
However, according to RFC 1813 section 3.3.21, NFSv3 COMMIT requests
are permitted to return only the following non-zero status codes:
NFS3ERR_IO
NFS3ERR_STALE
NFS3ERR_BADHANDLE
NFS3ERR_SERVERFAULT
NFS3ERR_INVAL is not included in that list. Likewise, NFS4ERR_INVAL
is not listed in the COMMIT row of Table 6 in RFC 8881.
RFC 7530 does permit COMMIT to return NFS4ERR_INVAL, but does not
specify when it can or should be used.
Instead of dropping or failing a COMMIT request in a byte range that
is not supported, turn it into a valid request by treating one or
both arguments as zero. Offset zero means start-of-file, count zero
means until-end-of-file, so we only ever extend the commit range.
NFS servers are always allowed to commit more and sooner than
requested.
The range check is no longer bounded by NFS_OFFSET_MAX, but rather
by the value that is returned in the maxfilesize field of the NFSv3
FSINFO procedure or the NFSv4 maxfilesize file attribute.
Note that this change results in a new pynfs failure:
CMT4 st_commit.testCommitOverflow : RUNNING
CMT4 st_commit.testCommitOverflow : FAILURE
COMMIT with offset + count overflow should return
NFS4ERR_INVAL, instead got NFS4_OK
IMO the test is not correct as written: RFC 8881 does not allow the
COMMIT operation to return NFS4ERR_INVAL.
Reported-by: Dan Aloni <dan.aloni@vastdata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
d6f1651ddf