/* AFS tracepoints * * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #undef TRACE_SYSTEM #define TRACE_SYSTEM afs #if !defined(_TRACE_AFS_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_AFS_H #include /* * Define enums for tracing information. */ #ifndef __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY #define __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY enum afs_call_trace { afs_call_trace_alloc, afs_call_trace_free, afs_call_trace_put, afs_call_trace_wake, afs_call_trace_work, }; #endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */ /* * Declare tracing information enums and their string mappings for display. */ #define afs_call_traces \ EM(afs_call_trace_alloc, "ALLOC") \ EM(afs_call_trace_free, "FREE ") \ EM(afs_call_trace_put, "PUT ") \ EM(afs_call_trace_wake, "WAKE ") \ E_(afs_call_trace_work, "WORK ") /* * Export enum symbols via userspace. */ #undef EM #undef E_ #define EM(a, b) TRACE_DEFINE_ENUM(a); #define E_(a, b) TRACE_DEFINE_ENUM(a); afs_call_traces; /* * Now redefine the EM() and E_() macros to map the enums to the strings that * will be printed in the output. */ #undef EM #undef E_ #define EM(a, b) { a, b }, #define E_(a, b) { a, b } TRACE_EVENT(afs_recv_data, TP_PROTO(struct afs_call *call, unsigned count, unsigned offset, bool want_more, int ret), TP_ARGS(call, count, offset, want_more, ret), TP_STRUCT__entry( __field(struct rxrpc_call *, rxcall ) __field(struct afs_call *, call ) __field(enum afs_call_state, state ) __field(unsigned int, count ) __field(unsigned int, offset ) __field(unsigned short, unmarshall ) __field(bool, want_more ) __field(int, ret ) ), TP_fast_assign( __entry->rxcall = call->rxcall; __entry->call = call; __entry->state = call->state; __entry->unmarshall = call->unmarshall; __entry->count = count; __entry->offset = offset; __entry->want_more = want_more; __entry->ret = ret; ), TP_printk("c=%p ac=%p s=%u u=%u %u/%u wm=%u ret=%d", __entry->rxcall, __entry->call, __entry->state, __entry->unmarshall, __entry->offset, __entry->count, __entry->want_more, __entry->ret) ); TRACE_EVENT(afs_notify_call, TP_PROTO(struct rxrpc_call *rxcall, struct afs_call *call), TP_ARGS(rxcall, call), TP_STRUCT__entry( __field(struct rxrpc_call *, rxcall ) __field(struct afs_call *, call ) __field(enum afs_call_state, state ) __field(unsigned short, unmarshall ) ), TP_fast_assign( __entry->rxcall = rxcall; __entry->call = call; __entry->state = call->state; __entry->unmarshall = call->unmarshall; ), TP_printk("c=%p ac=%p s=%u u=%u", __entry->rxcall, __entry->call, __entry->state, __entry->unmarshall) ); TRACE_EVENT(afs_cb_call, TP_PROTO(struct afs_call *call), TP_ARGS(call), TP_STRUCT__entry( __field(struct rxrpc_call *, rxcall ) __field(struct afs_call *, call ) __field(const char *, name ) __field(u32, op ) ), TP_fast_assign( __entry->rxcall = call->rxcall; __entry->call = call; __entry->name = call->type->name; __entry->op = call->operation_ID; ), TP_printk("c=%p ac=%p %s o=%u", __entry->rxcall, __entry->call, __entry->name, __entry->op) ); TRACE_EVENT(afs_call, TP_PROTO(struct afs_call *call, enum afs_call_trace op, int usage, int outstanding, const void *where), TP_ARGS(call, op, usage, outstanding, where), TP_STRUCT__entry( __field(struct afs_call *, call ) __field(int, op ) __field(int, usage ) __field(int, outstanding ) __field(const void *, where ) ), TP_fast_assign( __entry->call = call; __entry->op = op; __entry->usage = usage; __entry->outstanding = outstanding; __entry->where = where; ), TP_printk("c=%p %s u=%d o=%d sp=%pSR", __entry->call, __print_symbolic(__entry->op, afs_call_traces), __entry->usage, __entry->outstanding, __entry->where) ); #endif /* _TRACE_AFS_H */ /* This part must be outside protection */ #include t.git/commit/Documentation/sh?id=efd1535270c1deb0487527bf0c3c827301a69c93'>efd1535270c1deb0487527bf0c3c827301a69c93 (patch) treee0afb0ad9d8e7db1ed1d52ba4c07e2278ff2b7c4 /Documentation/sh parent116f7d4a21fe450efc652c4850eb27cda36c9db0 (diff)
xen-blkfront: don't call talk_to_blkback when already connected to blkback
Sometimes blkfront may twice receive blkback_changed() notification (XenbusStateConnected) after migration, which will cause talk_to_blkback() to be called twice too and confuse xen-blkback. The flow is as follow: blkfront blkback blkfront_resume() > talk_to_blkback() > Set blkfront to XenbusStateInitialised front changed() > Connect() > Set blkback to XenbusStateConnected blkback_changed() > Skip talk_to_blkback() because frontstate == XenbusStateInitialised > blkfront_connect() > Set blkfront to XenbusStateConnected ----- And here we get another XenbusStateConnected notification leading to: ----- blkback_changed() > because now frontstate != XenbusStateInitialised talk_to_blkback() is also called again > blkfront state changed from XenbusStateConnected to XenbusStateInitialised (Which is not correct!) front_changed(): > Do nothing because blkback already in XenbusStateConnected Now blkback is in XenbusStateConnected but blkfront is still in XenbusStateInitialised - leading to no disks. Poking of the XenbusStateConnected state is allowed (to deal with block disk change) and has to be dealt with. The most likely cause of this bug are custom udev scripts hooking up the disks and then validating the size. Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'Documentation/sh')