diff options
| author | Long Li <longli@microsoft.com> | 2018-04-17 22:17:07 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2018-04-25 19:15:58 +0300 |
| commit | 8bcda1d2a79da4ab84162574eee2c9f6e1a12a03 (patch) | |
| tree | 943add8ef3369365347c413c295f8ff3e7664c7a /fs | |
| parent | bb4c0419476bd3982ba802f0f49de83cd79532d8 (diff) | |
| download | linux-8bcda1d2a79da4ab84162574eee2c9f6e1a12a03.tar.xz | |
cifs: smbd: Avoid allocating iov on the stack
It's not necessary to allocate another iov when going through the buffers
in smbd_send() through RDMA send.
Remove it to reduce stack size.
Thanks to Matt for spotting a printk typo in the earlier version of this.
CC: Matt Redfearn <matt.redfearn@mips.com>
Signed-off-by: Long Li <longli@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <smfrench@gmail.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/smbdirect.c | 36 |
1 files changed, 12 insertions, 24 deletions
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index 87817ddcc096..c62f7c95683c 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -2086,7 +2086,7 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst) int start, i, j; int max_iov_size = info->max_send_size - sizeof(struct smbd_data_transfer); - struct kvec iov[SMBDIRECT_MAX_SGE]; + struct kvec *iov; int rc; info->smbd_send_pending++; @@ -2096,32 +2096,20 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst) } /* - * This usually means a configuration error - * We use RDMA read/write for packet size > rdma_readwrite_threshold - * as long as it's properly configured we should never get into this - * situation - */ - if (rqst->rq_nvec + rqst->rq_npages > SMBDIRECT_MAX_SGE) { - log_write(ERR, "maximum send segment %x exceeding %x\n", - rqst->rq_nvec + rqst->rq_npages, SMBDIRECT_MAX_SGE); - rc = -EINVAL; - goto done; - } - - /* - * Remove the RFC1002 length defined in MS-SMB2 section 2.1 - * It is used only for TCP transport + * Skip the RFC1002 length defined in MS-SMB2 section 2.1 + * It is used only for TCP transport in the iov[0] * In future we may want to add a transport layer under protocol * layer so this will only be issued to TCP transport */ - iov[0].iov_base = (char *)rqst->rq_iov[0].iov_base + 4; - iov[0].iov_len = rqst->rq_iov[0].iov_len - 4; - buflen += iov[0].iov_len; + + if (rqst->rq_iov[0].iov_len != 4) { + log_write(ERR, "expected the pdu length in 1st iov, but got %zu\n", rqst->rq_iov[0].iov_len); + return -EINVAL; + } + iov = &rqst->rq_iov[1]; /* total up iov array first */ - for (i = 1; i < rqst->rq_nvec; i++) { - iov[i].iov_base = rqst->rq_iov[i].iov_base; - iov[i].iov_len = rqst->rq_iov[i].iov_len; + for (i = 0; i < rqst->rq_nvec-1; i++) { buflen += iov[i].iov_len; } @@ -2198,14 +2186,14 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst) goto done; } i++; - if (i == rqst->rq_nvec) + if (i == rqst->rq_nvec-1) break; } start = i; buflen = 0; } else { i++; - if (i == rqst->rq_nvec) { + if (i == rqst->rq_nvec-1) { /* send out all remaining vecs */ remaining_data_length -= buflen; log_write(INFO, |