kernel-ark/net/sunrpc/xprtrdma/xprt_rdma.h
Tom Tucker 5c635e09ce RPCRDMA: Fix FRMR registration/invalidate handling.
When the rpc_memreg_strategy is 5, FRMR are used to map RPC data.
This mode uses an FRMR to map the RPC data, then invalidates
(i.e. unregisers) the data in xprt_rdma_free. These FRMR are used
across connections on the same mount, i.e. if the connection goes
away on an idle timeout and reconnects later, the FRMR are not
destroyed and recreated.

This creates a problem for transport errors because the WR that
invalidate an FRMR may be flushed (i.e. fail) leaving the
FRMR valid. When the FRMR is later used to map an RPC it will fail,
tearing down the transport and starting over. Over time, more and
more of the FRMR pool end up in the wrong state resulting in
seemingly random disconnects.

This fix keeps track of the FRMR state explicitly by setting it's
state based on the successful completion of a reg/inv WR. If the FRMR
is ever used and found to be in the wrong state, an invalidate WR
is prepended, re-syncing the FRMR state and avoiding the connection loss.

Signed-off-by: Tom Tucker <tom@ogc.us>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:39:27 -05:00

347 lines
12 KiB
C

/*
* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
*
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#ifndef _LINUX_SUNRPC_XPRT_RDMA_H
#define _LINUX_SUNRPC_XPRT_RDMA_H
#include <linux/wait.h> /* wait_queue_head_t, etc */
#include <linux/spinlock.h> /* spinlock_t, etc */
#include <asm/atomic.h> /* atomic_t, etc */
#include <rdma/rdma_cm.h> /* RDMA connection api */
#include <rdma/ib_verbs.h> /* RDMA verbs api */
#include <linux/sunrpc/clnt.h> /* rpc_xprt */
#include <linux/sunrpc/rpc_rdma.h> /* RPC/RDMA protocol */
#include <linux/sunrpc/xprtrdma.h> /* xprt parameters */
#define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */
#define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */
/*
* Interface Adapter -- one per transport instance
*/
struct rpcrdma_ia {
struct rdma_cm_id *ri_id;
struct ib_pd *ri_pd;
struct ib_mr *ri_bind_mem;
u32 ri_dma_lkey;
int ri_have_dma_lkey;
struct completion ri_done;
int ri_async_rc;
enum rpcrdma_memreg ri_memreg_strategy;
};
/*
* RDMA Endpoint -- one per transport instance
*/
struct rpcrdma_ep {
atomic_t rep_cqcount;
int rep_cqinit;
int rep_connected;
struct rpcrdma_ia *rep_ia;
struct ib_cq *rep_cq;
struct ib_qp_init_attr rep_attr;
wait_queue_head_t rep_connect_wait;
struct ib_sge rep_pad; /* holds zeroed pad */
struct ib_mr *rep_pad_mr; /* holds zeroed pad */
void (*rep_func)(struct rpcrdma_ep *);
struct rpc_xprt *rep_xprt; /* for rep_func */
struct rdma_conn_param rep_remote_cma;
struct sockaddr_storage rep_remote_addr;
};
#define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
#define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
/*
* struct rpcrdma_rep -- this structure encapsulates state required to recv
* and complete a reply, asychronously. It needs several pieces of
* state:
* o recv buffer (posted to provider)
* o ib_sge (also donated to provider)
* o status of reply (length, success or not)
* o bookkeeping state to get run by tasklet (list, etc)
*
* These are allocated during initialization, per-transport instance;
* however, the tasklet execution list itself is global, as it should
* always be pretty short.
*
* N of these are associated with a transport instance, and stored in
* struct rpcrdma_buffer. N is the max number of outstanding requests.
*/
/* temporary static scatter/gather max */
#define RPCRDMA_MAX_DATA_SEGS (8) /* max scatter/gather */
#define RPCRDMA_MAX_SEGS (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
#define MAX_RPCRDMAHDR (\
/* max supported RPC/RDMA header */ \
sizeof(struct rpcrdma_msg) + (2 * sizeof(u32)) + \
(sizeof(struct rpcrdma_read_chunk) * RPCRDMA_MAX_SEGS) + sizeof(u32))
struct rpcrdma_buffer;
struct rpcrdma_rep {
unsigned int rr_len; /* actual received reply length */
struct rpcrdma_buffer *rr_buffer; /* home base for this structure */
struct rpc_xprt *rr_xprt; /* needed for request/reply matching */
void (*rr_func)(struct rpcrdma_rep *);/* called by tasklet in softint */
struct list_head rr_list; /* tasklet list */
wait_queue_head_t rr_unbind; /* optional unbind wait */
struct ib_sge rr_iov; /* for posting */
struct ib_mr *rr_handle; /* handle for mem in rr_iov */
char rr_base[MAX_RPCRDMAHDR]; /* minimal inline receive buffer */
};
/*
* struct rpcrdma_req -- structure central to the request/reply sequence.
*
* N of these are associated with a transport instance, and stored in
* struct rpcrdma_buffer. N is the max number of outstanding requests.
*
* It includes pre-registered buffer memory for send AND recv.
* The recv buffer, however, is not owned by this structure, and
* is "donated" to the hardware when a recv is posted. When a
* reply is handled, the recv buffer used is given back to the
* struct rpcrdma_req associated with the request.
*
* In addition to the basic memory, this structure includes an array
* of iovs for send operations. The reason is that the iovs passed to
* ib_post_{send,recv} must not be modified until the work request
* completes.
*
* NOTES:
* o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
* marshal. The number needed varies depending on the iov lists that
* are passed to us, the memory registration mode we are in, and if
* physical addressing is used, the layout.
*/
struct rpcrdma_mr_seg { /* chunk descriptors */
union { /* chunk memory handles */
struct ib_mr *rl_mr; /* if registered directly */
struct rpcrdma_mw { /* if registered from region */
union {
struct ib_mw *mw;
struct ib_fmr *fmr;
struct {
struct ib_fast_reg_page_list *fr_pgl;
struct ib_mr *fr_mr;
enum { FRMR_IS_INVALID, FRMR_IS_VALID } state;
} frmr;
} r;
struct list_head mw_list;
} *rl_mw;
} mr_chunk;
u64 mr_base; /* registration result */
u32 mr_rkey; /* registration result */
u32 mr_len; /* length of chunk or segment */
int mr_nsegs; /* number of segments in chunk or 0 */
enum dma_data_direction mr_dir; /* segment mapping direction */
dma_addr_t mr_dma; /* segment mapping address */
size_t mr_dmalen; /* segment mapping length */
struct page *mr_page; /* owning page, if any */
char *mr_offset; /* kva if no page, else offset */
};
struct rpcrdma_req {
size_t rl_size; /* actual length of buffer */
unsigned int rl_niovs; /* 0, 2 or 4 */
unsigned int rl_nchunks; /* non-zero if chunks */
unsigned int rl_connect_cookie; /* retry detection */
struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
struct rpcrdma_rep *rl_reply;/* holder for reply buffer */
struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
struct ib_sge rl_send_iov[4]; /* for active requests */
struct ib_sge rl_iov; /* for posting */
struct ib_mr *rl_handle; /* handle for mem in rl_iov */
char rl_base[MAX_RPCRDMAHDR]; /* start of actual buffer */
__u32 rl_xdr_buf[0]; /* start of returned rpc rq_buffer */
};
#define rpcr_to_rdmar(r) \
container_of((r)->rq_buffer, struct rpcrdma_req, rl_xdr_buf[0])
/*
* struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
* inline requests/replies, and client/server credits.
*
* One of these is associated with a transport instance
*/
struct rpcrdma_buffer {
spinlock_t rb_lock; /* protects indexes */
atomic_t rb_credits; /* most recent server credits */
unsigned long rb_cwndscale; /* cached framework rpc_cwndscale */
int rb_max_requests;/* client max requests */
struct list_head rb_mws; /* optional memory windows/fmrs/frmrs */
int rb_send_index;
struct rpcrdma_req **rb_send_bufs;
int rb_recv_index;
struct rpcrdma_rep **rb_recv_bufs;
char *rb_pool;
};
#define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
/*
* Internal structure for transport instance creation. This
* exists primarily for modularity.
*
* This data should be set with mount options
*/
struct rpcrdma_create_data_internal {
struct sockaddr_storage addr; /* RDMA server address */
unsigned int max_requests; /* max requests (slots) in flight */
unsigned int rsize; /* mount rsize - max read hdr+data */
unsigned int wsize; /* mount wsize - max write hdr+data */
unsigned int inline_rsize; /* max non-rdma read data payload */
unsigned int inline_wsize; /* max non-rdma write data payload */
unsigned int padding; /* non-rdma write header padding */
};
#define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
(rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_rsize)
#define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
(rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_wsize)
#define RPCRDMA_INLINE_PAD_VALUE(rq)\
rpcx_to_rdmad(rq->rq_task->tk_xprt).padding
/*
* Statistics for RPCRDMA
*/
struct rpcrdma_stats {
unsigned long read_chunk_count;
unsigned long write_chunk_count;
unsigned long reply_chunk_count;
unsigned long long total_rdma_request;
unsigned long long total_rdma_reply;
unsigned long long pullup_copy_count;
unsigned long long fixup_copy_count;
unsigned long hardway_register_count;
unsigned long failed_marshal_count;
unsigned long bad_reply_count;
};
/*
* RPCRDMA transport -- encapsulates the structures above for
* integration with RPC.
*
* The contained structures are embedded, not pointers,
* for convenience. This structure need not be visible externally.
*
* It is allocated and initialized during mount, and released
* during unmount.
*/
struct rpcrdma_xprt {
struct rpc_xprt xprt;
struct rpcrdma_ia rx_ia;
struct rpcrdma_ep rx_ep;
struct rpcrdma_buffer rx_buf;
struct rpcrdma_create_data_internal rx_data;
struct delayed_work rdma_connect;
struct rpcrdma_stats rx_stats;
};
#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt)
#define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
/* Setting this to 0 ensures interoperability with early servers.
* Setting this to 1 enhances certain unaligned read/write performance.
* Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
extern int xprt_rdma_pad_optimize;
/*
* Interface Adapter calls - xprtrdma/verbs.c
*/
int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
void rpcrdma_ia_close(struct rpcrdma_ia *);
/*
* Endpoint calls - xprtrdma/verbs.c
*/
int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
struct rpcrdma_create_data_internal *);
int rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
int rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
struct rpcrdma_req *);
int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
struct rpcrdma_rep *);
/*
* Buffer calls - xprtrdma/verbs.c
*/
int rpcrdma_buffer_create(struct rpcrdma_buffer *, struct rpcrdma_ep *,
struct rpcrdma_ia *,
struct rpcrdma_create_data_internal *);
void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
void rpcrdma_buffer_put(struct rpcrdma_req *);
void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
int rpcrdma_register_internal(struct rpcrdma_ia *, void *, int,
struct ib_mr **, struct ib_sge *);
int rpcrdma_deregister_internal(struct rpcrdma_ia *,
struct ib_mr *, struct ib_sge *);
int rpcrdma_register_external(struct rpcrdma_mr_seg *,
int, int, struct rpcrdma_xprt *);
int rpcrdma_deregister_external(struct rpcrdma_mr_seg *,
struct rpcrdma_xprt *, void *);
/*
* RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
*/
void rpcrdma_conn_func(struct rpcrdma_ep *);
void rpcrdma_reply_handler(struct rpcrdma_rep *);
/*
* RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
*/
int rpcrdma_marshal_req(struct rpc_rqst *);
#endif /* _LINUX_SUNRPC_XPRT_RDMA_H */