From 74dcf418fe344657b0e48a5a4b75f935443fa53f Mon Sep 17 00:00:00 2001 From: Long Li Date: Wed, 22 Nov 2017 17:38:46 -0700 Subject: [PATCH] CIFS: SMBD: Read correct returned data length for RDMA write (SMB read) I/O This patch is for preparing upper layer doing SMB read via RDMA write. When RDMA write is used for SMB read, the returned data length is in DataRemaining in the response packet. Reading it properly by adding a parameter to specifiy where the returned data length is. Add the defition for memory registration to wdata and return the correct length based on if RDMA write is used. Signed-off-by: Long Li Signed-off-by: Steve French Reviewed-by: Pavel Shilovsky Reviewed-by: Ronnie Sahlberg --- fs/cifs/cifsglob.h | 13 +++++++++++-- fs/cifs/cifssmb.c | 8 ++++++-- fs/cifs/smb1ops.c | 4 +++- fs/cifs/smb2ops.c | 12 ++++++++++-- 4 files changed, 30 insertions(+), 7 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 29b5a9bd3128..678e638c1e69 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -230,8 +230,14 @@ struct smb_version_operations { __u64 (*get_next_mid)(struct TCP_Server_Info *); /* data offset from read response message */ unsigned int (*read_data_offset)(char *); - /* data length from read response message */ - unsigned int (*read_data_length)(char *); + /* + * Data length from read response message + * When in_remaining is true, the returned data length is in + * message field DataRemaining for out-of-band data read (e.g through + * Memory Registration RDMA write in SMBD). + * Otherwise, the returned data length is in message field DataLength. + */ + unsigned int (*read_data_length)(char *, bool in_remaining); /* map smb to linux error */ int (*map_error)(char *, bool); /* find mid corresponding to the response message */ @@ -1152,6 +1158,9 @@ struct cifs_readdata { struct cifs_readdata *rdata, struct iov_iter *iter); struct kvec iov[2]; +#ifdef CONFIG_CIFS_SMB_DIRECT + struct smbd_mr *mr; +#endif unsigned int pagesz; unsigned int tailsz; unsigned int credits; diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 66d1ebfe75dd..49cf999f3d46 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -1455,6 +1455,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) struct cifs_readdata *rdata = mid->callback_data; char *buf = server->smallbuf; unsigned int buflen = get_rfc1002_length(buf) + 4; + bool use_rdma_mr = false; cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n", __func__, mid->mid, rdata->offset, rdata->bytes); @@ -1543,8 +1544,11 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) rdata->iov[0].iov_base, server->total_read); /* how much data is in the response? */ - data_len = server->ops->read_data_length(buf); - if (data_offset + data_len > buflen) { +#ifdef CONFIG_CIFS_SMB_DIRECT + use_rdma_mr = rdata->mr; +#endif + data_len = server->ops->read_data_length(buf, use_rdma_mr); + if (!use_rdma_mr && (data_offset + data_len > buflen)) { /* data_len is corrupt -- discard frame */ rdata->result = -EIO; return cifs_readv_discard(server, mid); diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index a723df3e0197..3d495e440c87 100644 --- a/fs/cifs/smb1ops.c +++ b/fs/cifs/smb1ops.c @@ -87,9 +87,11 @@ cifs_read_data_offset(char *buf) } static unsigned int -cifs_read_data_length(char *buf) +cifs_read_data_length(char *buf, bool in_remaining) { READ_RSP *rsp = (READ_RSP *)buf; + /* It's a bug reading remaining data for SMB1 packets */ + WARN_ON(in_remaining); return (le16_to_cpu(rsp->DataLengthHigh) << 16) + le16_to_cpu(rsp->DataLength); } diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index c8fa4c4ccc50..e3393ff5d458 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -957,9 +957,13 @@ smb2_read_data_offset(char *buf) } static unsigned int -smb2_read_data_length(char *buf) +smb2_read_data_length(char *buf, bool in_remaining) { struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf; + + if (in_remaining) + return le32_to_cpu(rsp->DataRemaining); + return le32_to_cpu(rsp->DataLength); } @@ -2421,6 +2425,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid, struct iov_iter iter; struct kvec iov; int length; + bool use_rdma_mr = false; if (shdr->Command != SMB2_READ) { cifs_dbg(VFS, "only big read responses are supported\n"); @@ -2447,7 +2452,10 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid, } data_offset = server->ops->read_data_offset(buf) + 4; - data_len = server->ops->read_data_length(buf); +#ifdef CONFIG_CIFS_SMB_DIRECT + use_rdma_mr = rdata->mr; +#endif + data_len = server->ops->read_data_length(buf, use_rdma_mr); if (data_offset < server->vals->read_rsp_size) { /* -- 2.30.2