5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chuck Lever chuck.lever@oracle.com
[ Upstream commit 76ce4dcec0dc08a032db916841ddc4e3998be317 ]
Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply at the same time.
Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large.
Add an NFSv4 helper that computes the size of the send buffer. It replaces svc_max_payload() in spots where svc_max_payload() returns a value that might be larger than the remaining send buffer space. Callers who need to know the transport's actual maximum payload size will continue to use svc_max_payload().
Signed-off-by: Chuck Lever chuck.lever@oracle.com --- fs/nfsd/nfs4proc.c | 48 +++++++++++++++++++++++----------------------- 1 file changed, 24 insertions(+), 24 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 59f675f194ebb..2e8f8b9fa3aeb 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2765,6 +2765,22 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
#define op_encode_channel_attrs_maxsz (6 + 1 + 1)
+/* + * The _rsize() helpers are invoked by the NFSv4 COMPOUND decoder, which + * is called before sunrpc sets rq_res.buflen. Thus we have to compute + * the maximum payload size here, based on transport limits and the size + * of the remaining space in the rq_pages array. + */ +static u32 nfsd4_max_payload(const struct svc_rqst *rqstp) +{ + u32 buflen; + + buflen = (rqstp->rq_page_end - rqstp->rq_next_page) * PAGE_SIZE; + buflen -= rqstp->rq_auth_slack; + buflen -= rqstp->rq_res.head[0].iov_len; + return min_t(u32, buflen, svc_max_payload(rqstp)); +} + static u32 nfsd4_only_status_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { @@ -2810,9 +2826,9 @@ static u32 nfsd4_getattr_rsize(const struct svc_rqst *rqstp, u32 ret = 0;
if (bmap0 & FATTR4_WORD0_ACL) - return svc_max_payload(rqstp); + return nfsd4_max_payload(rqstp); if (bmap0 & FATTR4_WORD0_FS_LOCATIONS) - return svc_max_payload(rqstp); + return nfsd4_max_payload(rqstp);
if (bmap1 & FATTR4_WORD1_OWNER) { ret += IDMAP_NAMESZ + 4; @@ -2872,10 +2888,7 @@ static u32 nfsd4_open_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_read_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = 0, rlen = 0; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.read.rd_length, maxcount); + u32 rlen = min(op->u.read.rd_length, nfsd4_max_payload(rqstp));
return (op_encode_hdr_size + 2 + XDR_QUADLEN(rlen)) * sizeof(__be32); } @@ -2883,8 +2896,7 @@ static u32 nfsd4_read_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_read_plus_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = svc_max_payload(rqstp); - u32 rlen = min(op->u.read.rd_length, maxcount); + u32 rlen = min(op->u.read.rd_length, nfsd4_max_payload(rqstp)); /* * If we detect that the file changed during hole encoding, then we * recover by encoding the remaining reply as data. This means we need @@ -2898,10 +2910,7 @@ static u32 nfsd4_read_plus_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_readdir_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = 0, rlen = 0; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.readdir.rd_maxcount, maxcount); + u32 rlen = min(op->u.readdir.rd_maxcount, nfsd4_max_payload(rqstp));
return (op_encode_hdr_size + op_encode_verifier_maxsz + XDR_QUADLEN(rlen)) * sizeof(__be32); @@ -3040,10 +3049,7 @@ static u32 nfsd4_copy_notify_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_getdeviceinfo_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = 0, rlen = 0; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.getdeviceinfo.gd_maxcount, maxcount); + u32 rlen = min(op->u.getdeviceinfo.gd_maxcount, nfsd4_max_payload(rqstp));
return (op_encode_hdr_size + 1 /* gd_layout_type*/ + @@ -3093,10 +3099,7 @@ static u32 nfsd4_seek_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_getxattr_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount, rlen; - - maxcount = svc_max_payload(rqstp); - rlen = min_t(u32, XATTR_SIZE_MAX, maxcount); + u32 rlen = min_t(u32, XATTR_SIZE_MAX, nfsd4_max_payload(rqstp));
return (op_encode_hdr_size + 1 + XDR_QUADLEN(rlen)) * sizeof(__be32); } @@ -3110,10 +3113,7 @@ static u32 nfsd4_setxattr_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_listxattrs_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount, rlen; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.listxattrs.lsxa_maxcount, maxcount); + u32 rlen = min(op->u.listxattrs.lsxa_maxcount, nfsd4_max_payload(rqstp));
return (op_encode_hdr_size + 4 + XDR_QUADLEN(rlen)) * sizeof(__be32); }