diff options
author | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2023-04-06 15:16:52 -0400 |
---|---|---|
committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2023-04-28 15:48:45 -0400 |
commit | fbd2a05f29a95d5b42b294bf47e55a711424965b (patch) | |
tree | 065a16290f26fa11199e2ce8f077748743ead50c /fs/nfs | |
parent | e025f0a73f6acb920d86549b2177a5883535421d (diff) | |
download | lwn-fbd2a05f29a95d5b42b294bf47e55a711424965b.tar.gz lwn-fbd2a05f29a95d5b42b294bf47e55a711424965b.zip |
NFSv4.2: Rework scratch handling for READ_PLUS
Instead of using a tiny, static scratch buffer, we should use a kmalloc()-ed
buffer that is allocated when checking for read plus usage. This lets us
use the buffer before decoding any part of the READ_PLUS operation
instead of setting it right before segment decoding, meaning it should
be a little more robust.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r-- | fs/nfs/nfs42xdr.c | 4 | ||||
-rw-r--r-- | fs/nfs/nfs4proc.c | 17 |
2 files changed, 14 insertions, 7 deletions
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c index d80ee88ca996..a6df815a140c 100644 --- a/fs/nfs/nfs42xdr.c +++ b/fs/nfs/nfs42xdr.c @@ -1122,7 +1122,6 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res) uint32_t segments; struct read_plus_segment *segs; int status, i; - char scratch_buf[16]; __be32 *p; status = decode_op_hdr(xdr, OP_READ_PLUS); @@ -1143,7 +1142,6 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res) if (!segs) return -ENOMEM; - xdr_set_scratch_buffer(xdr, &scratch_buf, sizeof(scratch_buf)); status = -EIO; for (i = 0; i < segments; i++) { status = decode_read_plus_segment(xdr, &segs[i]); @@ -1348,6 +1346,8 @@ static int nfs4_xdr_dec_read_plus(struct rpc_rqst *rqstp, struct compound_hdr hdr; int status; + xdr_set_scratch_buffer(xdr, res->scratch, sizeof(res->scratch)); + status = decode_compound_hdr(xdr, &hdr); if (status) goto out; diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 5607b1e2b821..18f25ff4bff7 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5439,6 +5439,8 @@ static bool nfs4_read_plus_not_supported(struct rpc_task *task, static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr) { + if (hdr->res.scratch) + kfree(hdr->res.scratch); if (!nfs4_sequence_done(task, &hdr->res.seq_res)) return -EAGAIN; if (nfs4_read_stateid_changed(task, &hdr->args)) @@ -5452,17 +5454,22 @@ static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr) } #if defined CONFIG_NFS_V4_2 && defined CONFIG_NFS_V4_2_READ_PLUS -static void nfs42_read_plus_support(struct nfs_pgio_header *hdr, +static bool nfs42_read_plus_support(struct nfs_pgio_header *hdr, struct rpc_message *msg) { /* Note: We don't use READ_PLUS with pNFS yet */ - if (nfs_server_capable(hdr->inode, NFS_CAP_READ_PLUS) && !hdr->ds_clp) + if (nfs_server_capable(hdr->inode, NFS_CAP_READ_PLUS) && !hdr->ds_clp) { msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ_PLUS]; + hdr->res.scratch = kmalloc(32, GFP_KERNEL); + return hdr->res.scratch != NULL; + } + return false; } #else -static void nfs42_read_plus_support(struct nfs_pgio_header *hdr, +static bool nfs42_read_plus_support(struct nfs_pgio_header *hdr, struct rpc_message *msg) { + return false; } #endif /* CONFIG_NFS_V4_2 */ @@ -5472,8 +5479,8 @@ static void nfs4_proc_read_setup(struct nfs_pgio_header *hdr, hdr->timestamp = jiffies; if (!hdr->pgio_done_cb) hdr->pgio_done_cb = nfs4_read_done_cb; - msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ]; - nfs42_read_plus_support(hdr, msg); + if (!nfs42_read_plus_support(hdr, msg)) + msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ]; nfs4_init_sequence(&hdr->args.seq_args, &hdr->res.seq_res, 0, 0); } |