From db223a590d45b5e584a430c46a778699a5825cdd Mon Sep 17 00:00:00 2001 From: Long Li Date: Wed, 22 Nov 2017 17:38:45 -0700 Subject: [PATCH] CIFS: SMBD: Upper layer performs SMB write via RDMA read through memory registration When sending I/O, if size is larger than rdma_readwrite_threshold we prepare to send SMB write packet for a RDMA read via memory registration. The actual I/O is done by remote peer through local RDMA hardware. Modify the relevant fields in the packet accordingly, and append a smbd_buffer_descriptor_v1 to the end of the SMB write packet. On write I/O finish, deregister the memory region if this was for a RDMA read. If remote invalidation is not used, the call to smbd_deregister_mr will do local invalidation and possibly wait. Memory region is normally deregistered in MID callback as soon as it's used. There are situations where the MID may not be created on I/O failure, under which memory region is deregistered when write data context is released. Signed-off-by: Long Li Signed-off-by: Steve French Reviewed-by: Pavel Shilovsky Reviewed-by: Ronnie Sahlberg --- fs/cifs/cifsglob.h | 3 +++ fs/cifs/cifssmb.c | 7 ++++++ fs/cifs/smb2pdu.c | 63 ++++++++++++++++++++++++++++++++++++++++++++-- 3 files changed, 71 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 573a7bef8817..29b5a9bd3128 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1174,6 +1174,9 @@ struct cifs_writedata { pid_t pid; unsigned int bytes; int result; +#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 35dc5bf01ee2..66d1ebfe75dd 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -43,6 +43,7 @@ #include "cifs_unicode.h" #include "cifs_debug.h" #include "fscache.h" +#include "smbdirect.h" #ifdef CONFIG_CIFS_POSIX static struct { @@ -1923,6 +1924,12 @@ cifs_writedata_release(struct kref *refcount) { struct cifs_writedata *wdata = container_of(refcount, struct cifs_writedata, refcount); +#ifdef CONFIG_CIFS_SMB_DIRECT + if (wdata->mr) { + smbd_deregister_mr(wdata->mr); + wdata->mr = NULL; + } +#endif if (wdata->cfile) cifsFileInfo_put(wdata->cfile); diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index c0dc0491af93..908d7770d15a 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -48,6 +48,7 @@ #include "smb2glob.h" #include "cifspdu.h" #include "cifs_spnego.h" +#include "smbdirect.h" /* * The following table defines the expected "StructureSize" of SMB2 requests @@ -2728,7 +2729,19 @@ smb2_writev_callback(struct mid_q_entry *mid) wdata->result = -EIO; break; } - +#ifdef CONFIG_CIFS_SMB_DIRECT + /* + * If this wdata has a memory registered, the MR can be freed + * The number of MRs available is limited, it's important to recover + * used MR as soon as I/O is finished. Hold MR longer in the later + * I/O process can possibly result in I/O deadlock due to lack of MR + * to send request on I/O retry + */ + if (wdata->mr) { + smbd_deregister_mr(wdata->mr); + wdata->mr = NULL; + } +#endif if (wdata->result) cifs_stats_fail_inc(tcon, SMB2_WRITE_HE); @@ -2780,7 +2793,42 @@ smb2_async_writev(struct cifs_writedata *wdata, req->DataOffset = cpu_to_le16( offsetof(struct smb2_write_req, Buffer)); req->RemainingBytes = 0; +#ifdef CONFIG_CIFS_SMB_DIRECT + /* + * If we want to do a server RDMA read, fill in and append + * smbd_buffer_descriptor_v1 to the end of write request + */ + if (server->rdma && wdata->bytes >= + server->smbd_conn->rdma_readwrite_threshold) { + struct smbd_buffer_descriptor_v1 *v1; + bool need_invalidate = server->dialect == SMB30_PROT_ID; + + wdata->mr = smbd_register_mr( + server->smbd_conn, wdata->pages, + wdata->nr_pages, wdata->tailsz, + false, need_invalidate); + if (!wdata->mr) { + rc = -ENOBUFS; + goto async_writev_out; + } + req->Length = 0; + req->DataOffset = 0; + req->RemainingBytes = + (wdata->nr_pages-1)*PAGE_SIZE + wdata->tailsz; + req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE; + if (need_invalidate) + req->Channel = SMB2_CHANNEL_RDMA_V1; + req->WriteChannelInfoOffset = + offsetof(struct smb2_write_req, Buffer); + req->WriteChannelInfoLength = + sizeof(struct smbd_buffer_descriptor_v1); + v1 = (struct smbd_buffer_descriptor_v1 *) &req->Buffer[0]; + v1->offset = wdata->mr->mr->iova; + v1->token = wdata->mr->mr->rkey; + v1->length = wdata->mr->mr->length; + } +#endif /* 4 for rfc1002 length field and 1 for Buffer */ iov[0].iov_len = 4; rfc1002_marker = cpu_to_be32(total_len - 1 + wdata->bytes); @@ -2794,11 +2842,22 @@ smb2_async_writev(struct cifs_writedata *wdata, rqst.rq_npages = wdata->nr_pages; rqst.rq_pagesz = wdata->pagesz; rqst.rq_tailsz = wdata->tailsz; - +#ifdef CONFIG_CIFS_SMB_DIRECT + if (wdata->mr) { + iov[1].iov_len += sizeof(struct smbd_buffer_descriptor_v1); + rqst.rq_npages = 0; + } +#endif cifs_dbg(FYI, "async write at %llu %u bytes\n", wdata->offset, wdata->bytes); +#ifdef CONFIG_CIFS_SMB_DIRECT + /* For RDMA read, I/O size is in RemainingBytes not in Length */ + if (!wdata->mr) + req->Length = cpu_to_le32(wdata->bytes); +#else req->Length = cpu_to_le32(wdata->bytes); +#endif if (wdata->credits) { shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,