user/sven/linux.git/include/trace, branch v3.2.78

jbd2: issue cache flush after checkpointing even with internal journal

2015-08-12T14:33:15Z

commit 79feb521a44705262d15cc819a4117a447b11ea7 upstream. When we reach jbd2_cleanup_journal_tail(), there is no guarantee that checkpointed buffers are on a stable storage - especially if buffers were written out by jbd2_log_do_checkpoint(), they are likely to be only in disk's caches. Thus when we update journal superblock effectively removing old transaction from journal, this write of superblock can get to stable storage before those checkpointed buffers which can result in filesystem corruption after a crash. Thus we must unconditionally issue a cache flush before we update journal superblock in these cases. A similar problem can also occur if journal superblock is written only in disk's caches, other transaction starts reusing space of the transaction cleaned from the log and power failure happens. Subsequent journal replay would still try to replay the old transaction but some of it's blocks may be already overwritten by the new transaction. For this reason we must use WRITE_FUA when updating log tail and we must first write new log tail to disk and update in-memory information only after that. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" [bwh: Prerequisite for "jbd2: fix ocfs2 corrupt when updating journal superblock fails". Backported to 3.2: - Adjust context - Drop changes to jbd2_journal_update_sb_log_tail trace event] Signed-off-by: Ben Hutchings

tracing: Fix syscall_*regfunc() vs copy_process() race

2014-07-11T12:33:53Z

commit 4af4206be2bd1933cae20c2b6fb2058dbc887f7c upstream. syscall_regfunc() and syscall_unregfunc() should set/clear TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race with copy_process() and miss the new child which was not added to the process/thread lists yet. Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT under tasklist. Link: http://lkml.kernel.org/p/20140413185854.GB20668@redhat.com Fixes: a871bd33a6c0 "tracing: Add syscall tracepoints" Acked-by: Frederic Weisbecker Acked-by: Paul E. McKenney Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings

trace: module: Maintain a valid user count

2014-06-09T12:29:10Z

commit 098507ae3ec2331476fb52e85d4040c1cc6d0ef4 upstream. The replacement of the 'count' variable by two variables 'incs' and 'decs' to resolve some race conditions during module unloading was done in parallel with some cleanup in the trace subsystem, and was integrated as a merge. Unfortunately, the formula for this replacement was wrong in the tracing code, and the refcount in the traces was not usable as a result. Use 'count = incs - decs' to compute the user count. Link: http://lkml.kernel.org/p/1393924179-9147-1-git-send-email-romain.izard.pro@gmail.com Acked-by: Ingo Molnar Cc: Rusty Russell Cc: Frederic Weisbecker Fixes: c1ab9cab7509 "merge conflict resolution" Signed-off-by: Romain Izard Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings

blktrace: fix accounting of partially completed requests

2014-04-30T15:23:20Z

commit af5040da01ef980670b3741b3e10733ee3e33566 upstream. trace_block_rq_complete does not take into account that request can be partially completed, so we can get the following incorrect output of blkparser: C R 232 + 240 [0] C R 240 + 232 [0] C R 248 + 224 [0] C R 256 + 216 [0] but should be: C R 232 + 8 [0] C R 240 + 8 [0] C R 248 + 8 [0] C R 256 + 8 [0] Also, the whole output summary statistics of completed requests and final throughput will be incorrect. This patch takes into account real completion size of the request and fixes wrong completion accounting. Signed-off-by: Roman Pen CC: Steven Rostedt CC: Frederic Weisbecker CC: Ingo Molnar CC: linux-kernel@vger.kernel.org Signed-off-by: Jens Axboe [bwh: Backported to 3.2: drop change in blk-mq.c] Signed-off-by: Ben Hutchings

tracing: Allow events to have NULL strings

2014-01-03T04:33:26Z

commit 4e58e54754dc1fec21c3a9e824bc108b05fdf46e upstream. If an TRACE_EVENT() uses __assign_str() or __get_str on a NULL pointer then the following oops will happen: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] strlen+0x10/0x1a *pde = 00000000 ^M Oops: 0000 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.13.0-rc1-test+ #2 Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006^M task: f5cde9f0 ti: f5e5e000 task.ti: f5e5e000 EIP: 0060:[] EFLAGS: 00210046 CPU: 1 EIP is at strlen+0x10/0x1a EAX: 00000000 EBX: c2472da8 ECX: ffffffff EDX: c2472da8 ESI: c1c5e5fc EDI: 00000000 EBP: f5e5fe84 ESP: f5e5fe80 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 CR0: 8005003b CR2: 00000000 CR3: 01f32000 CR4: 000007d0 Stack: f5f18b90 f5e5feb8 c10687a8 0759004f 00000005 00000005 00000005 00200046 00000002 00000000 c1082a93 f56c7e28 c2472da8 c1082a93 f5e5fee4 c106bc61^M 00000000 c1082a93 00000000 00000000 00000001 00200046 00200082 00000000 Call Trace: [] ftrace_raw_event_lock+0x39/0xc0 [] ? ktime_get+0x29/0x69 [] ? ktime_get+0x29/0x69 [] lock_release+0x57/0x1a5 [] ? ktime_get+0x29/0x69 [] read_seqcount_begin.constprop.7+0x4d/0x75 [] ? ktime_get+0x29/0x69^M [] ktime_get+0x29/0x69 [] __tick_nohz_idle_enter+0x1e/0x426 [] ? lock_release_holdtime.part.19+0x48/0x4d [] ? time_hardirqs_off+0xe/0x28 [] ? trace_hardirqs_off_caller+0x3f/0xaf [] tick_nohz_idle_enter+0x59/0x62 [] cpu_startup_entry+0x64/0x192 [] start_secondary+0x277/0x27c Code: 90 89 c6 89 d0 88 c4 ac 38 e0 74 09 84 c0 75 f7 be 01 00 00 00 89 f0 48 5e 5d c3 55 89 e5 57 66 66 66 66 90 83 c9 ff 89 c7 31 c0 ae f7 d1 8d 41 ff 5f 5d c3 55 89 e5 57 66 66 66 66 90 31 ff EIP: [] strlen+0x10/0x1a SS:ESP 0068:f5e5fe80 CR2: 0000000000000000 ---[ end trace 01bc47bf519ec1b2 ]--- New tracepoints have been added that have allowed for NULL pointers being assigned to strings. To fix this, change the TRACE_EVENT() code to check for NULL and if it is, it will assign "(null)" to it instead (similar to what glibc printf does). Reported-by: Shuah Khan Reported-by: Jovi Zhangwei Link: http://lkml.kernel.org/r/CAGdX0WFeEuy+DtpsJzyzn0343qEEjLX97+o1VREFkUEhndC+5Q@mail.gmail.com Link: http://lkml.kernel.org/r/528D6972.9010702@samsung.com Fixes: 9cbf117662e2 ("tracing/events: provide string with undefined size support") Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings

xen/mmu: Use Xen specific TLB flush instead of the generic one.

2012-11-16T16:47:03Z

commit 95a7d76897c1e7243d4137037c66d15cbf2cce76 upstream. As Mukesh explained it, the MMUEXT_TLB_FLUSH_ALL allows the hypervisor to do a TLB flush on all active vCPUs. If instead we were using the generic one (which ends up being xen_flush_tlb) we end up making the MMUEXT_TLB_FLUSH_LOCAL hypercall. But before we make that hypercall the kernel will IPI all of the vCPUs (even those that were asleep from the hypervisor perspective). The end result is that we needlessly wake them up and do a TLB flush when we can just let the hypervisor do it correctly. This patch gives around 50% speed improvement when migrating idle guest's from one host to another. Oracle-bug: 14630170 Tested-by: Jingjie Jiang Suggested-by: Mukesh Rathor Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Ben Hutchings

tracing: Don't call page_to_pfn() if page is NULL

2012-10-10T02:31:00Z

commit 85f2a2ef1d0ab99523e0b947a2b723f5650ed6aa upstream. When allocating memory fails, page is NULL. page_to_pfn() will cause the kernel panicked if we don't use sparsemem vmemmap. Link: http://lkml.kernel.org/r/505AB1FF.8020104@cn.fujitsu.com Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Andrew Morton Acked-by: Mel Gorman Reviewed-by: Minchan Kim Signed-off-by: Wen Congyang Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings

writeback: fix dereferencing NULL bdi->dev on trace_writeback_queue

2012-02-20T20:46:17Z

commit 977b7e3a52a7421ad33a393a38ece59f3d41c2fa upstream. When a SD card is hot removed without umount, del_gendisk() will call bdi_unregister() without destroying/freeing it. This leaves the bdi in the bdi->dev = NULL, bdi->wb.task = NULL, bdi->bdi_list removed state. When sync(2) gets the bdi before bdi_unregister() and calls bdi_queue_work() after the unregister, trace_writeback_queue will be dereferencing the NULL bdi->dev. Fix it with a simple test for NULL. LKML-reference: http://lkml.org/lkml/2012/1/18/346 Reported-by: Rabin Vincent Tested-by: Namjae Jeon Signed-off-by: Wu Fengguang Signed-off-by: Greg Kroah-Hartman

writeback: fix NULL bdi->dev in trace writeback_single_inode

2012-02-20T20:46:16Z

commit 15eb77a07c714ac80201abd0a9568888bcee6276 upstream. bdi_prune_sb() resets sb->s_bdi to default_backing_dev_info when the tearing down the original bdi. Fix trace_writeback_single_inode to use sb->s_bdi=default_backing_dev_info rather than bdi->dev=NULL for a teared down bdi. Reported-by: Rabin Vincent Tested-by: Rabin Vincent Signed-off-by: Wu Fengguang Signed-off-by: Greg Kroah-Hartman

writeback: show writeback reason with __print_symbolic

2011-12-18T06:20:17Z

This makes the binary trace understandable by trace-cmd. CC: Dave Chinner CC: Curt Wohlgemuth CC: Steven Rostedt Signed-off-by: Wu Fengguang