6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells dhowells@redhat.com
[ Upstream commit 519be989717c5bffaed1dc14a439e3872cb4bb8d ]
Add a tracepoint to track the credit changes and server in_flight value involved in the lifetime of a R/W request, logging it against the request/subreq debugging ID. This requires the debugging IDs to be recorded in the cifs_credits struct.
The tracepoint can be enabled with:
echo 1 >/sys/kernel/debug/tracing/events/cifs/smb3_rw_credits/enable
Also add a three-state flag to struct cifs_credits to note if we're interested in determining when the in_flight contribution ends and, if so, to track whether we've decremented the contribution yet.
Signed-off-by: David Howells dhowells@redhat.com Reviewed-by: Paulo Alcantara (Red Hat) pc@manguebit.com cc: Jeff Layton jlayton@kernel.org cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Steve French stfrench@microsoft.com Stable-dep-of: 74c2ab6d653b ("smb/client: avoid possible NULL dereference in cifs_free_subrequest()") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifsglob.h | 17 +++++++----- fs/smb/client/file.c | 32 ++++++++++++++++++++++- fs/smb/client/smb1ops.c | 2 +- fs/smb/client/smb2ops.c | 42 ++++++++++++++++++++++++++---- fs/smb/client/smb2pdu.c | 40 +++++++++++++++++++++++++--- fs/smb/client/trace.h | 55 ++++++++++++++++++++++++++++++++++++++- fs/smb/client/transport.c | 8 +++--- 7 files changed, 173 insertions(+), 23 deletions(-)
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index d4bcc7da700c6..0a271b9fbc622 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -290,7 +290,7 @@ struct smb_version_operations { int (*check_receive)(struct mid_q_entry *, struct TCP_Server_Info *, bool); void (*add_credits)(struct TCP_Server_Info *server, - const struct cifs_credits *credits, + struct cifs_credits *credits, const int optype); void (*set_credits)(struct TCP_Server_Info *, const int); int * (*get_credits_field)(struct TCP_Server_Info *, const int); @@ -550,8 +550,8 @@ struct smb_version_operations { size_t *, struct cifs_credits *); /* adjust previously taken mtu credits to request size */ int (*adjust_credits)(struct TCP_Server_Info *server, - struct cifs_credits *credits, - const unsigned int payload_size); + struct cifs_io_subrequest *subreq, + unsigned int /*enum smb3_rw_credits_trace*/ trace); /* check if we need to issue closedir */ bool (*dir_needs_close)(struct cifsFileInfo *); long (*fallocate)(struct file *, struct cifs_tcon *, int, loff_t, @@ -848,6 +848,9 @@ static inline void cifs_server_unlock(struct TCP_Server_Info *server) struct cifs_credits { unsigned int value; unsigned int instance; + unsigned int in_flight_check; + unsigned int rreq_debug_id; + unsigned int rreq_debug_index; };
static inline unsigned int @@ -873,7 +876,7 @@ has_credits(struct TCP_Server_Info *server, int *credits, int num_credits) }
static inline void -add_credits(struct TCP_Server_Info *server, const struct cifs_credits *credits, +add_credits(struct TCP_Server_Info *server, struct cifs_credits *credits, const int optype) { server->ops->add_credits(server, credits, optype); @@ -897,11 +900,11 @@ set_credits(struct TCP_Server_Info *server, const int val) }
static inline int -adjust_credits(struct TCP_Server_Info *server, struct cifs_credits *credits, - const unsigned int payload_size) +adjust_credits(struct TCP_Server_Info *server, struct cifs_io_subrequest *subreq, + unsigned int /* enum smb3_rw_credits_trace */ trace) { return server->ops->adjust_credits ? - server->ops->adjust_credits(server, credits, payload_size) : 0; + server->ops->adjust_credits(server, subreq, trace) : 0; }
static inline __le64 diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index 9e4f4e67768b9..b413cfef05422 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -80,6 +80,16 @@ static void cifs_prepare_write(struct netfs_io_subrequest *subreq) return netfs_prepare_write_failed(subreq); }
+ wdata->credits.rreq_debug_id = subreq->rreq->debug_id; + wdata->credits.rreq_debug_index = subreq->debug_index; + wdata->credits.in_flight_check = 1; + trace_smb3_rw_credits(wdata->rreq->debug_id, + wdata->subreq.debug_index, + wdata->credits.value, + server->credits, server->in_flight, + wdata->credits.value, + cifs_trace_rw_credits_write_prepare); + #ifdef CONFIG_CIFS_SMB_DIRECT if (server->smbd_conn) subreq->max_nr_segs = server->smbd_conn->max_frmr_depth; @@ -101,7 +111,7 @@ static void cifs_issue_write(struct netfs_io_subrequest *subreq) goto fail; }
- rc = adjust_credits(wdata->server, &wdata->credits, wdata->subreq.len); + rc = adjust_credits(wdata->server, wdata, cifs_trace_rw_credits_issue_write_adjust); if (rc) goto fail;
@@ -163,7 +173,18 @@ static bool cifs_clamp_length(struct netfs_io_subrequest *subreq) return false; }
+ rdata->credits.in_flight_check = 1; + rdata->credits.rreq_debug_id = rreq->debug_id; + rdata->credits.rreq_debug_index = subreq->debug_index; + + trace_smb3_rw_credits(rdata->rreq->debug_id, + rdata->subreq.debug_index, + rdata->credits.value, + server->credits, server->in_flight, 0, + cifs_trace_rw_credits_read_submit); + subreq->len = min_t(size_t, subreq->len, rsize); + #ifdef CONFIG_CIFS_SMB_DIRECT if (server->smbd_conn) subreq->max_nr_segs = server->smbd_conn->max_frmr_depth; @@ -295,6 +316,15 @@ static void cifs_free_subrequest(struct netfs_io_subrequest *subreq) #endif }
+ if (rdata->credits.value != 0) + trace_smb3_rw_credits(rdata->rreq->debug_id, + rdata->subreq.debug_index, + rdata->credits.value, + rdata->server ? rdata->server->credits : 0, + rdata->server ? rdata->server->in_flight : 0, + -rdata->credits.value, + cifs_trace_rw_credits_free_subreq); + add_credits_and_wake_if(rdata->server, &rdata->credits, 0); if (rdata->have_xid) free_xid(rdata->xid); diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c index 212ec6f66ec65..e1f2feb56f45f 100644 --- a/fs/smb/client/smb1ops.c +++ b/fs/smb/client/smb1ops.c @@ -108,7 +108,7 @@ cifs_find_mid(struct TCP_Server_Info *server, char *buffer)
static void cifs_add_credits(struct TCP_Server_Info *server, - const struct cifs_credits *credits, const int optype) + struct cifs_credits *credits, const int optype) { spin_lock(&server->req_lock); server->credits += credits->value; diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index c8e536540895a..7fe59235f0901 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -66,7 +66,7 @@ change_conf(struct TCP_Server_Info *server)
static void smb2_add_credits(struct TCP_Server_Info *server, - const struct cifs_credits *credits, const int optype) + struct cifs_credits *credits, const int optype) { int *val, rc = -1; int scredits, in_flight; @@ -94,7 +94,21 @@ smb2_add_credits(struct TCP_Server_Info *server, server->conn_id, server->hostname, *val, add, server->in_flight); } - WARN_ON_ONCE(server->in_flight == 0); + if (credits->in_flight_check > 1) { + pr_warn_once("rreq R=%08x[%x] Credits not in flight\n", + credits->rreq_debug_id, credits->rreq_debug_index); + } else { + credits->in_flight_check = 2; + } + if (WARN_ON_ONCE(server->in_flight == 0)) { + pr_warn_once("rreq R=%08x[%x] Zero in_flight\n", + credits->rreq_debug_id, credits->rreq_debug_index); + trace_smb3_rw_credits(credits->rreq_debug_id, + credits->rreq_debug_index, + credits->value, + server->credits, server->in_flight, 0, + cifs_trace_rw_credits_zero_in_flight); + } server->in_flight--; if (server->in_flight == 0 && ((optype & CIFS_OP_MASK) != CIFS_NEG_OP) && @@ -283,16 +297,23 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, size_t size,
static int smb2_adjust_credits(struct TCP_Server_Info *server, - struct cifs_credits *credits, - const unsigned int payload_size) + struct cifs_io_subrequest *subreq, + unsigned int /*enum smb3_rw_credits_trace*/ trace) { - int new_val = DIV_ROUND_UP(payload_size, SMB2_MAX_BUFFER_SIZE); + struct cifs_credits *credits = &subreq->credits; + int new_val = DIV_ROUND_UP(subreq->subreq.len, SMB2_MAX_BUFFER_SIZE); int scredits, in_flight;
if (!credits->value || credits->value == new_val) return 0;
if (credits->value < new_val) { + trace_smb3_rw_credits(subreq->rreq->debug_id, + subreq->subreq.debug_index, + credits->value, + server->credits, server->in_flight, + new_val - credits->value, + cifs_trace_rw_credits_no_adjust_up); trace_smb3_too_many_credits(server->CurrentMid, server->conn_id, server->hostname, 0, credits->value - new_val, 0); cifs_server_dbg(VFS, "request has less credits (%d) than required (%d)", @@ -308,6 +329,12 @@ smb2_adjust_credits(struct TCP_Server_Info *server, in_flight = server->in_flight; spin_unlock(&server->req_lock);
+ trace_smb3_rw_credits(subreq->rreq->debug_id, + subreq->subreq.debug_index, + credits->value, + server->credits, server->in_flight, + new_val - credits->value, + cifs_trace_rw_credits_old_session); trace_smb3_reconnect_detected(server->CurrentMid, server->conn_id, server->hostname, scredits, credits->value - new_val, in_flight); @@ -316,6 +343,11 @@ smb2_adjust_credits(struct TCP_Server_Info *server, return -EAGAIN; }
+ trace_smb3_rw_credits(subreq->rreq->debug_id, + subreq->subreq.debug_index, + credits->value, + server->credits, server->in_flight, + new_val - credits->value, trace); server->credits += credits->value - new_val; scredits = server->credits; in_flight = server->in_flight; diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index 896147ba6660e..4cd5c33be2a1a 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -4505,8 +4505,15 @@ smb2_readv_callback(struct mid_q_entry *mid) struct TCP_Server_Info *server = rdata->server; struct smb2_hdr *shdr = (struct smb2_hdr *)rdata->iov[0].iov_base; - struct cifs_credits credits = { .value = 0, .instance = 0 }; + struct cifs_credits credits = { + .value = 0, + .instance = 0, + .rreq_debug_id = rdata->rreq->debug_id, + .rreq_debug_index = rdata->subreq.debug_index, + }; struct smb_rqst rqst = { .rq_iov = &rdata->iov[1], .rq_nvec = 1 }; + unsigned int rreq_debug_id = rdata->rreq->debug_id; + unsigned int subreq_debug_index = rdata->subreq.debug_index;
if (rdata->got_bytes) { rqst.rq_iter = rdata->subreq.io_iter; @@ -4590,10 +4597,16 @@ smb2_readv_callback(struct mid_q_entry *mid) if (rdata->subreq.start < rdata->subreq.rreq->i_size) rdata->result = 0; } + trace_smb3_rw_credits(rreq_debug_id, subreq_debug_index, rdata->credits.value, + server->credits, server->in_flight, + 0, cifs_trace_rw_credits_read_response_clear); rdata->credits.value = 0; INIT_WORK(&rdata->subreq.work, smb2_readv_worker); queue_work(cifsiod_wq, &rdata->subreq.work); release_mid(mid); + trace_smb3_rw_credits(rreq_debug_id, subreq_debug_index, 0, + server->credits, server->in_flight, + credits.value, cifs_trace_rw_credits_read_response_add); add_credits(server, &credits, 0); }
@@ -4650,7 +4663,7 @@ smb2_async_readv(struct cifs_io_subrequest *rdata) min_t(int, server->max_credits - server->credits, credit_request));
- rc = adjust_credits(server, &rdata->credits, rdata->subreq.len); + rc = adjust_credits(server, rdata, cifs_trace_rw_credits_call_readv_adjust); if (rc) goto async_readv_out;
@@ -4769,7 +4782,14 @@ smb2_writev_callback(struct mid_q_entry *mid) struct cifs_tcon *tcon = tlink_tcon(wdata->req->cfile->tlink); struct TCP_Server_Info *server = wdata->server; struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf; - struct cifs_credits credits = { .value = 0, .instance = 0 }; + struct cifs_credits credits = { + .value = 0, + .instance = 0, + .rreq_debug_id = wdata->rreq->debug_id, + .rreq_debug_index = wdata->subreq.debug_index, + }; + unsigned int rreq_debug_id = wdata->rreq->debug_id; + unsigned int subreq_debug_index = wdata->subreq.debug_index; ssize_t result = 0; size_t written;
@@ -4840,9 +4860,15 @@ smb2_writev_callback(struct mid_q_entry *mid) tcon->tid, tcon->ses->Suid, wdata->subreq.start, wdata->subreq.len);
+ trace_smb3_rw_credits(rreq_debug_id, subreq_debug_index, wdata->credits.value, + server->credits, server->in_flight, + 0, cifs_trace_rw_credits_write_response_clear); wdata->credits.value = 0; cifs_write_subrequest_terminated(wdata, result ?: written, true); release_mid(mid); + trace_smb3_rw_credits(rreq_debug_id, subreq_debug_index, 0, + server->credits, server->in_flight, + credits.value, cifs_trace_rw_credits_write_response_add); add_credits(server, &credits, 0); }
@@ -4972,7 +4998,7 @@ smb2_async_writev(struct cifs_io_subrequest *wdata) min_t(int, server->max_credits - server->credits, credit_request));
- rc = adjust_credits(server, &wdata->credits, io_parms->length); + rc = adjust_credits(server, wdata, cifs_trace_rw_credits_call_writev_adjust); if (rc) goto async_writev_out;
@@ -4997,6 +5023,12 @@ smb2_async_writev(struct cifs_io_subrequest *wdata) cifs_small_buf_release(req); out: if (rc) { + trace_smb3_rw_credits(wdata->rreq->debug_id, + wdata->subreq.debug_index, + wdata->credits.value, + server->credits, server->in_flight, + -(int)wdata->credits.value, + cifs_trace_rw_credits_write_response_clear); add_credits_and_wake_if(wdata->server, &wdata->credits, 0); cifs_write_subrequest_terminated(wdata, rc, true); } diff --git a/fs/smb/client/trace.h b/fs/smb/client/trace.h index 36d47ce596317..36d5295c2a6f9 100644 --- a/fs/smb/client/trace.h +++ b/fs/smb/client/trace.h @@ -20,6 +20,22 @@ /* * Specify enums for tracing information. */ +#define smb3_rw_credits_traces \ + EM(cifs_trace_rw_credits_call_readv_adjust, "rd-call-adj") \ + EM(cifs_trace_rw_credits_call_writev_adjust, "wr-call-adj") \ + EM(cifs_trace_rw_credits_free_subreq, "free-subreq") \ + EM(cifs_trace_rw_credits_issue_read_adjust, "rd-issu-adj") \ + EM(cifs_trace_rw_credits_issue_write_adjust, "wr-issu-adj") \ + EM(cifs_trace_rw_credits_no_adjust_up, "no-adj-up ") \ + EM(cifs_trace_rw_credits_old_session, "old-session") \ + EM(cifs_trace_rw_credits_read_response_add, "rd-resp-add") \ + EM(cifs_trace_rw_credits_read_response_clear, "rd-resp-clr") \ + EM(cifs_trace_rw_credits_read_submit, "rd-submit ") \ + EM(cifs_trace_rw_credits_write_prepare, "wr-prepare ") \ + EM(cifs_trace_rw_credits_write_response_add, "wr-resp-add") \ + EM(cifs_trace_rw_credits_write_response_clear, "wr-resp-clr") \ + E_(cifs_trace_rw_credits_zero_in_flight, "ZERO-IN-FLT") + #define smb3_tcon_ref_traces \ EM(netfs_trace_tcon_ref_dec_dfs_refer, "DEC DfsRef") \ EM(netfs_trace_tcon_ref_free, "FRE ") \ @@ -59,7 +75,8 @@ #define EM(a, b) a, #define E_(a, b) a
-enum smb3_tcon_ref_trace { smb3_tcon_ref_traces } __mode(byte); +enum smb3_rw_credits_trace { smb3_rw_credits_traces } __mode(byte); +enum smb3_tcon_ref_trace { smb3_tcon_ref_traces } __mode(byte);
#undef EM #undef E_ @@ -71,6 +88,7 @@ enum smb3_tcon_ref_trace { smb3_tcon_ref_traces } __mode(byte); #define EM(a, b) TRACE_DEFINE_ENUM(a); #define E_(a, b) TRACE_DEFINE_ENUM(a);
+smb3_rw_credits_traces; smb3_tcon_ref_traces;
#undef EM @@ -1316,6 +1334,41 @@ TRACE_EVENT(smb3_tcon_ref, __entry->ref) );
+TRACE_EVENT(smb3_rw_credits, + TP_PROTO(unsigned int rreq_debug_id, + unsigned int subreq_debug_index, + unsigned int subreq_credits, + unsigned int server_credits, + int server_in_flight, + int credit_change, + enum smb3_rw_credits_trace trace), + TP_ARGS(rreq_debug_id, subreq_debug_index, subreq_credits, + server_credits, server_in_flight, credit_change, trace), + TP_STRUCT__entry( + __field(unsigned int, rreq_debug_id) + __field(unsigned int, subreq_debug_index) + __field(unsigned int, subreq_credits) + __field(unsigned int, server_credits) + __field(int, in_flight) + __field(int, credit_change) + __field(enum smb3_rw_credits_trace, trace) + ), + TP_fast_assign( + __entry->rreq_debug_id = rreq_debug_id; + __entry->subreq_debug_index = subreq_debug_index; + __entry->subreq_credits = subreq_credits; + __entry->server_credits = server_credits; + __entry->in_flight = server_in_flight; + __entry->credit_change = credit_change; + __entry->trace = trace; + ), + TP_printk("R=%08x[%x] %s cred=%u chg=%d pool=%u ifl=%d", + __entry->rreq_debug_id, __entry->subreq_debug_index, + __print_symbolic(__entry->trace, smb3_rw_credits_traces), + __entry->subreq_credits, __entry->credit_change, + __entry->server_credits, __entry->in_flight) + ); +
#undef EM #undef E_ diff --git a/fs/smb/client/transport.c b/fs/smb/client/transport.c index 012b9bd069952..adfe0d0587010 100644 --- a/fs/smb/client/transport.c +++ b/fs/smb/client/transport.c @@ -988,10 +988,10 @@ static void cifs_compound_callback(struct mid_q_entry *mid) { struct TCP_Server_Info *server = mid->server; - struct cifs_credits credits; - - credits.value = server->ops->get_credits(mid); - credits.instance = server->reconnect_instance; + struct cifs_credits credits = { + .value = server->ops->get_credits(mid), + .instance = server->reconnect_instance, + };
add_credits(server, &credits, mid->optype);