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| author | Chuck Lever <chuck.lever@oracle.com> | 2024-06-11 22:36:46 +0300 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2024-07-08 21:10:03 +0300 |
| commit | abc02e5602f7bf9bbae1e8999570a2ad5114578c (patch) | |
| tree | f1d5092cbd11fd6d6c89d2cea5c5ce4332480776 /fs/nfsd | |
| parent | e5d85ec52b1158ea6ea4834e5372bd7ba5862ffa (diff) | |
| download | linux-abc02e5602f7bf9bbae1e8999570a2ad5114578c.tar.xz | |
NFSD: Support write delegations in LAYOUTGET
I noticed LAYOUTGET(LAYOUTIOMODE4_RW) returning NFS4ERR_ACCESS
unexpectedly. The NFS client had created a file with mode 0444, and
the server had returned a write delegation on the OPEN(CREATE). The
client was requesting a RW layout using the write delegation stateid
so that it could flush file modifications.
Creating a read-only file does not seem to be problematic for
NFSv4.1 without pNFS, so I began looking at NFSD's implementation of
LAYOUTGET.
The failure was because fh_verify() was doing a permission check as
part of verifying the FH presented during the LAYOUTGET. It uses the
loga_iomode value to specify the @accmode argument to fh_verify().
fh_verify(MAY_WRITE) on a file whose mode is 0444 fails with -EACCES.
To permit LAYOUT* operations in this case, add OWNER_OVERRIDE when
checking the access permission of the incoming file handle for
LAYOUTGET and LAYOUTCOMMIT.
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # v6.6+
Message-Id: 4E9C0D74-A06D-4DC3-A48A-73034DC40395@oracle.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs4proc.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 46bd20fe5c0f..2e39cf2e502a 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2269,7 +2269,7 @@ nfsd4_layoutget(struct svc_rqst *rqstp, const struct nfsd4_layout_ops *ops; struct nfs4_layout_stateid *ls; __be32 nfserr; - int accmode = NFSD_MAY_READ_IF_EXEC; + int accmode = NFSD_MAY_READ_IF_EXEC | NFSD_MAY_OWNER_OVERRIDE; switch (lgp->lg_seg.iomode) { case IOMODE_READ: @@ -2359,7 +2359,8 @@ nfsd4_layoutcommit(struct svc_rqst *rqstp, struct nfs4_layout_stateid *ls; __be32 nfserr; - nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_WRITE); + nfserr = fh_verify(rqstp, current_fh, 0, + NFSD_MAY_WRITE | NFSD_MAY_OWNER_OVERRIDE); if (nfserr) goto out; |