The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3f965021c8bc38965ecb1924f570c4842b33d408 Mon Sep 17 00:00:00 2001 From: Chuck Lever chuck.lever@oracle.com Date: Mon, 24 Jan 2022 15:50:31 -0500 Subject: [PATCH] NFSD: COMMIT operations must not return NFS?ERR_INVAL

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

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index aca38ed1526e..52ad1972cc33 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -663,15 +663,9 @@ nfsd3_proc_commit(struct svc_rqst *rqstp) argp->count, (unsigned long long) argp->offset);

- if (argp->offset > NFS_OFFSET_MAX) { - resp->status = nfserr_inval; - goto out; - } - fh_copy(&resp->fh, &argp->fh); resp->status = nfsd_commit(rqstp, &resp->fh, argp->offset, argp->count, resp->verf); -out: return rpc_success; }

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 0cccceb105e7..91600e71be19 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1114,42 +1114,61 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, }

#ifdef CONFIG_NFSD_V3 -/* - * Commit all pending writes to stable storage. +/** + * nfsd_commit - Commit pending writes to stable storage + * @rqstp: RPC request being processed + * @fhp: NFS filehandle + * @offset: raw offset from beginning of file + * @count: raw count of bytes to sync + * @verf: filled in with the server's current write verifier * - * Note: we only guarantee that data that lies within the range specified - * by the 'offset' and 'count' parameters will be synced. + * Note: we guarantee that data that lies within the range specified + * by the 'offset' and 'count' parameters will be synced. The server + * is permitted to sync data that lies outside this range at the + * same time. * * Unfortunately we cannot lock the file to make sure we return full WCC * data to the client, as locking happens lower down in the filesystem. + * + * Return values: + * An nfsstat value in network byte order. */ __be32 -nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, - loff_t offset, unsigned long count, __be32 *verf) +nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, u64 offset, + u32 count, __be32 *verf) { + u64 maxbytes; + loff_t start, end; struct nfsd_net *nn; struct nfsd_file *nf; - loff_t end = LLONG_MAX; - __be32 err = nfserr_inval; - - if (offset < 0) - goto out; - if (count != 0) { - end = offset + (loff_t)count - 1; - if (end < offset) - goto out; - } + __be32 err;

err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf); if (err) goto out; + + /* + * Convert the client-provided (offset, count) range to a + * (start, end) range. If the client-provided range falls + * outside the maximum file size of the underlying FS, + * clamp the sync range appropriately. + */ + start = 0; + end = LLONG_MAX; + maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes; + if (offset < maxbytes) { + start = offset; + if (count && (offset + count - 1 < maxbytes)) + end = offset + count - 1; + } + nn = net_generic(nf->nf_net, nfsd_net_id); if (EX_ISSYNC(fhp->fh_export)) { errseq_t since = READ_ONCE(nf->nf_file->f_wb_err); int err2;

- err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); + err2 = vfs_fsync_range(nf->nf_file, start, end, 0); switch (err2) { case 0: nfsd_copy_write_verifier(verf, nn); diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index 9f56dcb22ff7..2c43d10e3cab 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -74,8 +74,8 @@ __be32 do_nfsd_create(struct svc_rqst *, struct svc_fh *, char *name, int len, struct iattr *attrs, struct svc_fh *res, int createmode, u32 *verifier, bool *truncp, bool *created); -__be32 nfsd_commit(struct svc_rqst *, struct svc_fh *, - loff_t, unsigned long, __be32 *verf); +__be32 nfsd_commit(struct svc_rqst *rqst, struct svc_fh *fhp, + u64 offset, u32 count, __be32 *verf); #endif /* CONFIG_NFSD_V3 */ #ifdef CONFIG_NFSD_V4 __be32 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,