forked from luck/tmp_suning_uos_patched
bad8e64fb1
On commit6ac93117ab
("blktrace: use existing disk debugfs directory") merged on v4.12 Omar fixed the original blktrace code for request-based drivers (multiqueue). This however left in place a possible crash, if you happen to abuse blktrace while racing to remove / add a device. We used to use asynchronous removal of the request_queue, and with that the issue was easier to reproduce. Now that we have reverted to synchronous removal of the request_queue, the issue is still possible to reproduce, its however just a bit more difficult. We essentially run two instances of break-blktrace which add/remove a loop device, and setup a blktrace and just never tear the blktrace down. We do this twice in parallel. This is easily reproduced with the script run_0004.sh from break-blktrace [0]. We can end up with two types of panics each reflecting where we race, one a failed blktrace setup: [ 252.426751] debugfs: Directory 'loop0' with parent 'block' already present! [ 252.432265] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 252.436592] #PF: supervisor write access in kernel mode [ 252.439822] #PF: error_code(0x0002) - not-present page [ 252.442967] PGD 0 P4D 0 [ 252.444656] Oops: 0002 [#1] SMP NOPTI [ 252.446972] CPU: 10 PID: 1153 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164 [ 252.452673] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 [ 252.456343] RIP: 0010:down_write+0x15/0x40 [ 252.458146] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00 00 00 <f0> 48 0f b1 55 00 75 0f 48 8b 04 25 c0 8b 01 00 48 89 45 08 5d [ 252.463638] RSP: 0018:ffffa626415abcc8 EFLAGS: 00010246 [ 252.464950] RAX: 0000000000000000 RBX: ffff958c25f0f5c0 RCX: ffffff8100000000 [ 252.466727] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0 [ 252.468482] RBP: 00000000000000a0 R08: 0000000000000000 R09: 0000000000000001 [ 252.470014] R10: 0000000000000000 R11: ffff958d1f9227ff R12: 0000000000000000 [ 252.471473] R13: ffff958c25ea5380 R14: ffffffff8cce15f1 R15: 00000000000000a0 [ 252.473346] FS: 00007f2e69dee540(0000) GS:ffff958c2fc80000(0000) knlGS:0000000000000000 [ 252.475225] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 252.476267] CR2: 00000000000000a0 CR3: 0000000427d10004 CR4: 0000000000360ee0 [ 252.477526] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 252.478776] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 252.479866] Call Trace: [ 252.480322] simple_recursive_removal+0x4e/0x2e0 [ 252.481078] ? debugfs_remove+0x60/0x60 [ 252.481725] ? relay_destroy_buf+0x77/0xb0 [ 252.482662] debugfs_remove+0x40/0x60 [ 252.483518] blk_remove_buf_file_callback+0x5/0x10 [ 252.484328] relay_close_buf+0x2e/0x60 [ 252.484930] relay_open+0x1ce/0x2c0 [ 252.485520] do_blk_trace_setup+0x14f/0x2b0 [ 252.486187] __blk_trace_setup+0x54/0xb0 [ 252.486803] blk_trace_ioctl+0x90/0x140 [ 252.487423] ? do_sys_openat2+0x1ab/0x2d0 [ 252.488053] blkdev_ioctl+0x4d/0x260 [ 252.488636] block_ioctl+0x39/0x40 [ 252.489139] ksys_ioctl+0x87/0xc0 [ 252.489675] __x64_sys_ioctl+0x16/0x20 [ 252.490380] do_syscall_64+0x52/0x180 [ 252.491032] entry_SYSCALL_64_after_hwframe+0x44/0xa9 And the other on the device removal: [ 128.528940] debugfs: Directory 'loop0' with parent 'block' already present! [ 128.615325] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 128.619537] #PF: supervisor write access in kernel mode [ 128.622700] #PF: error_code(0x0002) - not-present page [ 128.625842] PGD 0 P4D 0 [ 128.627585] Oops: 0002 [#1] SMP NOPTI [ 128.629871] CPU: 12 PID: 544 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164 [ 128.635595] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 [ 128.640471] RIP: 0010:down_write+0x15/0x40 [ 128.643041] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00 00 00 <f0> 48 0f b1 55 00 75 0f 65 48 8b 04 25 c0 8b 01 00 48 89 45 08 5d [ 128.650180] RSP: 0018:ffffa9c3c05ebd78 EFLAGS: 00010246 [ 128.651820] RAX: 0000000000000000 RBX: ffff8ae9a6370240 RCX: ffffff8100000000 [ 128.653942] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0 [ 128.655720] RBP: 00000000000000a0 R08: 0000000000000002 R09: ffff8ae9afd2d3d0 [ 128.657400] R10: 0000000000000056 R11: 0000000000000000 R12: 0000000000000000 [ 128.659099] R13: 0000000000000000 R14: 0000000000000003 R15: 00000000000000a0 [ 128.660500] FS: 00007febfd995540(0000) GS:ffff8ae9afd00000(0000) knlGS:0000000000000000 [ 128.662204] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 128.663426] CR2: 00000000000000a0 CR3: 0000000420042003 CR4: 0000000000360ee0 [ 128.664776] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 128.666022] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 128.667282] Call Trace: [ 128.667801] simple_recursive_removal+0x4e/0x2e0 [ 128.668663] ? debugfs_remove+0x60/0x60 [ 128.669368] debugfs_remove+0x40/0x60 [ 128.669985] blk_trace_free+0xd/0x50 [ 128.670593] __blk_trace_remove+0x27/0x40 [ 128.671274] blk_trace_shutdown+0x30/0x40 [ 128.671935] blk_release_queue+0x95/0xf0 [ 128.672589] kobject_put+0xa5/0x1b0 [ 128.673188] disk_release+0xa2/0xc0 [ 128.673786] device_release+0x28/0x80 [ 128.674376] kobject_put+0xa5/0x1b0 [ 128.674915] loop_remove+0x39/0x50 [loop] [ 128.675511] loop_control_ioctl+0x113/0x130 [loop] [ 128.676199] ksys_ioctl+0x87/0xc0 [ 128.676708] __x64_sys_ioctl+0x16/0x20 [ 128.677274] do_syscall_64+0x52/0x180 [ 128.677823] entry_SYSCALL_64_after_hwframe+0x44/0xa9 The common theme here is: debugfs: Directory 'loop0' with parent 'block' already present This crash happens because of how blktrace uses the debugfs directory where it places its files. Upon init we always create the same directory which would be needed by blktrace but we only do this for make_request drivers (multiqueue) block drivers. When you race a removal of these devices with a blktrace setup you end up in a situation where the make_request recursive debugfs removal will sweep away the blktrace files and then later blktrace will also try to remove individual dentries which are already NULL. The inverse is also possible and hence the two types of use after frees. We don't create the block debugfs directory on init for these types of block devices: * request-based block driver block devices * every possible partition * scsi-generic And so, this race should in theory only be possible with make_request drivers. We can fix the UAF by simply re-using the debugfs directory for make_request drivers (multiqueue) and only creating the ephemeral directory for the other type of block devices. The new clarifications on relying on the q->blk_trace_mutex *and* also checking for q->blk_trace *prior* to processing a blktrace ensures the debugfs directories are only created if no possible directory name clashes are possible. This goes tested with: o nvme partitions o ISCSI with tgt, and blktracing against scsi-generic with: o block o tape o cdrom o media changer o blktests This patch is part of the work which disputes the severity of CVE-2019-19770 which shows this issue is not a core debugfs issue, but a misuse of debugfs within blktace. Fixes:6ac93117ab
("blktrace: use existing disk debugfs directory") Reported-by: syzbot+603294af2d01acfdd6da@syzkaller.appspotmail.com Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Omar Sandoval <osandov@fb.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: yu kuai <yukuai3@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
1992 lines
47 KiB
C
1992 lines
47 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/blkdev.h>
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#include <linux/blktrace_api.h>
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#include <linux/percpu.h>
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#include <linux/init.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/debugfs.h>
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#include <linux/export.h>
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#include <linux/time.h>
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#include <linux/uaccess.h>
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#include <linux/list.h>
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#include <linux/blk-cgroup.h>
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#include "../../block/blk.h"
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#include <trace/events/block.h>
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#include "trace_output.h"
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#ifdef CONFIG_BLK_DEV_IO_TRACE
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static unsigned int blktrace_seq __read_mostly = 1;
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static struct trace_array *blk_tr;
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static bool blk_tracer_enabled __read_mostly;
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static LIST_HEAD(running_trace_list);
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static __cacheline_aligned_in_smp DEFINE_SPINLOCK(running_trace_lock);
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/* Select an alternative, minimalistic output than the original one */
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#define TRACE_BLK_OPT_CLASSIC 0x1
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#define TRACE_BLK_OPT_CGROUP 0x2
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#define TRACE_BLK_OPT_CGNAME 0x4
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static struct tracer_opt blk_tracer_opts[] = {
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/* Default disable the minimalistic output */
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{ TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
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#ifdef CONFIG_BLK_CGROUP
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{ TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) },
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{ TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) },
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#endif
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{ }
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};
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static struct tracer_flags blk_tracer_flags = {
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.val = 0,
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.opts = blk_tracer_opts,
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};
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/* Global reference count of probes */
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static DEFINE_MUTEX(blk_probe_mutex);
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static int blk_probes_ref;
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static void blk_register_tracepoints(void);
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static void blk_unregister_tracepoints(void);
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/*
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* Send out a notify message.
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*/
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static void trace_note(struct blk_trace *bt, pid_t pid, int action,
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const void *data, size_t len, u64 cgid)
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{
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struct blk_io_trace *t;
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struct ring_buffer_event *event = NULL;
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struct trace_buffer *buffer = NULL;
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int pc = 0;
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int cpu = smp_processor_id();
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bool blk_tracer = blk_tracer_enabled;
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ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
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if (blk_tracer) {
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buffer = blk_tr->array_buffer.buffer;
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pc = preempt_count();
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event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
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sizeof(*t) + len + cgid_len,
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0, pc);
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if (!event)
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return;
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t = ring_buffer_event_data(event);
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goto record_it;
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}
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if (!bt->rchan)
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return;
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t = relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len);
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if (t) {
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t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
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t->time = ktime_to_ns(ktime_get());
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record_it:
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t->device = bt->dev;
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t->action = action | (cgid ? __BLK_TN_CGROUP : 0);
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t->pid = pid;
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t->cpu = cpu;
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t->pdu_len = len + cgid_len;
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if (cgid_len)
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memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
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memcpy((void *) t + sizeof(*t) + cgid_len, data, len);
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if (blk_tracer)
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trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc);
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}
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}
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/*
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* Send out a notify for this process, if we haven't done so since a trace
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* started
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*/
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static void trace_note_tsk(struct task_struct *tsk)
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{
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unsigned long flags;
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struct blk_trace *bt;
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tsk->btrace_seq = blktrace_seq;
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spin_lock_irqsave(&running_trace_lock, flags);
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list_for_each_entry(bt, &running_trace_list, running_list) {
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trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm,
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sizeof(tsk->comm), 0);
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}
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spin_unlock_irqrestore(&running_trace_lock, flags);
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}
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static void trace_note_time(struct blk_trace *bt)
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{
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struct timespec64 now;
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unsigned long flags;
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u32 words[2];
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/* need to check user space to see if this breaks in y2038 or y2106 */
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ktime_get_real_ts64(&now);
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words[0] = (u32)now.tv_sec;
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words[1] = now.tv_nsec;
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local_irq_save(flags);
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trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0);
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local_irq_restore(flags);
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}
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void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
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const char *fmt, ...)
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{
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int n;
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va_list args;
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unsigned long flags;
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char *buf;
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if (unlikely(bt->trace_state != Blktrace_running &&
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!blk_tracer_enabled))
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return;
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/*
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* If the BLK_TC_NOTIFY action mask isn't set, don't send any note
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* message to the trace.
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*/
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if (!(bt->act_mask & BLK_TC_NOTIFY))
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return;
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local_irq_save(flags);
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buf = this_cpu_ptr(bt->msg_data);
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va_start(args, fmt);
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n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
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va_end(args);
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if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
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blkcg = NULL;
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#ifdef CONFIG_BLK_CGROUP
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trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n,
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blkcg ? cgroup_id(blkcg->css.cgroup) : 1);
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#else
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trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, 0);
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#endif
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL_GPL(__trace_note_message);
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static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
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pid_t pid)
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{
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if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
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return 1;
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if (sector && (sector < bt->start_lba || sector > bt->end_lba))
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return 1;
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if (bt->pid && pid != bt->pid)
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return 1;
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return 0;
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}
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/*
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* Data direction bit lookup
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*/
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static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
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BLK_TC_ACT(BLK_TC_WRITE) };
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#define BLK_TC_RAHEAD BLK_TC_AHEAD
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#define BLK_TC_PREFLUSH BLK_TC_FLUSH
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/* The ilog2() calls fall out because they're constant */
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#define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
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(ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
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/*
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* The worker for the various blk_add_trace*() types. Fills out a
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* blk_io_trace structure and places it in a per-cpu subbuffer.
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*/
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static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
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int op, int op_flags, u32 what, int error, int pdu_len,
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void *pdu_data, u64 cgid)
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{
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struct task_struct *tsk = current;
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struct ring_buffer_event *event = NULL;
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struct trace_buffer *buffer = NULL;
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struct blk_io_trace *t;
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unsigned long flags = 0;
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unsigned long *sequence;
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pid_t pid;
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int cpu, pc = 0;
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bool blk_tracer = blk_tracer_enabled;
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ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
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if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
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return;
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what |= ddir_act[op_is_write(op) ? WRITE : READ];
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what |= MASK_TC_BIT(op_flags, SYNC);
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what |= MASK_TC_BIT(op_flags, RAHEAD);
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what |= MASK_TC_BIT(op_flags, META);
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what |= MASK_TC_BIT(op_flags, PREFLUSH);
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what |= MASK_TC_BIT(op_flags, FUA);
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if (op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE)
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what |= BLK_TC_ACT(BLK_TC_DISCARD);
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if (op == REQ_OP_FLUSH)
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what |= BLK_TC_ACT(BLK_TC_FLUSH);
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if (cgid)
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what |= __BLK_TA_CGROUP;
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pid = tsk->pid;
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if (act_log_check(bt, what, sector, pid))
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return;
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cpu = raw_smp_processor_id();
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if (blk_tracer) {
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tracing_record_cmdline(current);
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buffer = blk_tr->array_buffer.buffer;
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pc = preempt_count();
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event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
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sizeof(*t) + pdu_len + cgid_len,
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0, pc);
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if (!event)
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return;
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t = ring_buffer_event_data(event);
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goto record_it;
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}
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if (unlikely(tsk->btrace_seq != blktrace_seq))
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trace_note_tsk(tsk);
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/*
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* A word about the locking here - we disable interrupts to reserve
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* some space in the relay per-cpu buffer, to prevent an irq
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* from coming in and stepping on our toes.
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*/
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local_irq_save(flags);
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t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_len);
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if (t) {
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sequence = per_cpu_ptr(bt->sequence, cpu);
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t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
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t->sequence = ++(*sequence);
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t->time = ktime_to_ns(ktime_get());
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record_it:
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/*
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* These two are not needed in ftrace as they are in the
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* generic trace_entry, filled by tracing_generic_entry_update,
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* but for the trace_event->bin() synthesizer benefit we do it
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* here too.
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*/
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t->cpu = cpu;
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t->pid = pid;
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t->sector = sector;
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t->bytes = bytes;
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t->action = what;
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t->device = bt->dev;
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t->error = error;
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t->pdu_len = pdu_len + cgid_len;
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if (cgid_len)
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memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
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if (pdu_len)
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memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
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if (blk_tracer) {
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trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc);
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return;
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}
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}
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local_irq_restore(flags);
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}
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static void blk_trace_free(struct blk_trace *bt)
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{
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debugfs_remove(bt->msg_file);
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debugfs_remove(bt->dropped_file);
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relay_close(bt->rchan);
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debugfs_remove(bt->dir);
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free_percpu(bt->sequence);
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|
free_percpu(bt->msg_data);
|
|
kfree(bt);
|
|
}
|
|
|
|
static void get_probe_ref(void)
|
|
{
|
|
mutex_lock(&blk_probe_mutex);
|
|
if (++blk_probes_ref == 1)
|
|
blk_register_tracepoints();
|
|
mutex_unlock(&blk_probe_mutex);
|
|
}
|
|
|
|
static void put_probe_ref(void)
|
|
{
|
|
mutex_lock(&blk_probe_mutex);
|
|
if (!--blk_probes_ref)
|
|
blk_unregister_tracepoints();
|
|
mutex_unlock(&blk_probe_mutex);
|
|
}
|
|
|
|
static void blk_trace_cleanup(struct blk_trace *bt)
|
|
{
|
|
synchronize_rcu();
|
|
blk_trace_free(bt);
|
|
put_probe_ref();
|
|
}
|
|
|
|
static int __blk_trace_remove(struct request_queue *q)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
bt = rcu_replace_pointer(q->blk_trace, NULL,
|
|
lockdep_is_held(&q->blk_trace_mutex));
|
|
if (!bt)
|
|
return -EINVAL;
|
|
|
|
if (bt->trace_state != Blktrace_running)
|
|
blk_trace_cleanup(bt);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int blk_trace_remove(struct request_queue *q)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&q->blk_trace_mutex);
|
|
ret = __blk_trace_remove(q);
|
|
mutex_unlock(&q->blk_trace_mutex);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_trace_remove);
|
|
|
|
static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct blk_trace *bt = filp->private_data;
|
|
char buf[16];
|
|
|
|
snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
|
|
|
|
return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
|
|
}
|
|
|
|
static const struct file_operations blk_dropped_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = simple_open,
|
|
.read = blk_dropped_read,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
char *msg;
|
|
struct blk_trace *bt;
|
|
|
|
if (count >= BLK_TN_MAX_MSG)
|
|
return -EINVAL;
|
|
|
|
msg = memdup_user_nul(buffer, count);
|
|
if (IS_ERR(msg))
|
|
return PTR_ERR(msg);
|
|
|
|
bt = filp->private_data;
|
|
__trace_note_message(bt, NULL, "%s", msg);
|
|
kfree(msg);
|
|
|
|
return count;
|
|
}
|
|
|
|
static const struct file_operations blk_msg_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = simple_open,
|
|
.write = blk_msg_write,
|
|
.llseek = noop_llseek,
|
|
};
|
|
|
|
/*
|
|
* Keep track of how many times we encountered a full subbuffer, to aid
|
|
* the user space app in telling how many lost events there were.
|
|
*/
|
|
static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
|
|
void *prev_subbuf, size_t prev_padding)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
if (!relay_buf_full(buf))
|
|
return 1;
|
|
|
|
bt = buf->chan->private_data;
|
|
atomic_inc(&bt->dropped);
|
|
return 0;
|
|
}
|
|
|
|
static int blk_remove_buf_file_callback(struct dentry *dentry)
|
|
{
|
|
debugfs_remove(dentry);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct dentry *blk_create_buf_file_callback(const char *filename,
|
|
struct dentry *parent,
|
|
umode_t mode,
|
|
struct rchan_buf *buf,
|
|
int *is_global)
|
|
{
|
|
return debugfs_create_file(filename, mode, parent, buf,
|
|
&relay_file_operations);
|
|
}
|
|
|
|
static struct rchan_callbacks blk_relay_callbacks = {
|
|
.subbuf_start = blk_subbuf_start_callback,
|
|
.create_buf_file = blk_create_buf_file_callback,
|
|
.remove_buf_file = blk_remove_buf_file_callback,
|
|
};
|
|
|
|
static void blk_trace_setup_lba(struct blk_trace *bt,
|
|
struct block_device *bdev)
|
|
{
|
|
struct hd_struct *part = NULL;
|
|
|
|
if (bdev)
|
|
part = bdev->bd_part;
|
|
|
|
if (part) {
|
|
bt->start_lba = part->start_sect;
|
|
bt->end_lba = part->start_sect + part->nr_sects;
|
|
} else {
|
|
bt->start_lba = 0;
|
|
bt->end_lba = -1ULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Setup everything required to start tracing
|
|
*/
|
|
static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
|
|
struct block_device *bdev,
|
|
struct blk_user_trace_setup *buts)
|
|
{
|
|
struct blk_trace *bt = NULL;
|
|
struct dentry *dir = NULL;
|
|
int ret;
|
|
|
|
lockdep_assert_held(&q->blk_trace_mutex);
|
|
|
|
if (!buts->buf_size || !buts->buf_nr)
|
|
return -EINVAL;
|
|
|
|
if (!blk_debugfs_root)
|
|
return -ENOENT;
|
|
|
|
strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
|
|
buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
|
|
|
|
/*
|
|
* some device names have larger paths - convert the slashes
|
|
* to underscores for this to work as expected
|
|
*/
|
|
strreplace(buts->name, '/', '_');
|
|
|
|
/*
|
|
* bdev can be NULL, as with scsi-generic, this is a helpful as
|
|
* we can be.
|
|
*/
|
|
if (rcu_dereference_protected(q->blk_trace,
|
|
lockdep_is_held(&q->blk_trace_mutex))) {
|
|
pr_warn("Concurrent blktraces are not allowed on %s\n",
|
|
buts->name);
|
|
return -EBUSY;
|
|
}
|
|
|
|
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
|
|
if (!bt)
|
|
return -ENOMEM;
|
|
|
|
ret = -ENOMEM;
|
|
bt->sequence = alloc_percpu(unsigned long);
|
|
if (!bt->sequence)
|
|
goto err;
|
|
|
|
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
|
|
if (!bt->msg_data)
|
|
goto err;
|
|
|
|
#ifdef CONFIG_BLK_DEBUG_FS
|
|
/*
|
|
* When tracing whole make_request drivers (multiqueue) block devices,
|
|
* reuse the existing debugfs directory created by the block layer on
|
|
* init. For request-based block devices, all partitions block devices,
|
|
* and scsi-generic block devices we create a temporary new debugfs
|
|
* directory that will be removed once the trace ends.
|
|
*/
|
|
if (queue_is_mq(q) && bdev && bdev == bdev->bd_contains)
|
|
dir = q->debugfs_dir;
|
|
else
|
|
#endif
|
|
bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
|
|
|
|
bt->dev = dev;
|
|
atomic_set(&bt->dropped, 0);
|
|
INIT_LIST_HEAD(&bt->running_list);
|
|
|
|
ret = -EIO;
|
|
bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
|
|
&blk_dropped_fops);
|
|
|
|
bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
|
|
|
|
bt->rchan = relay_open("trace", dir, buts->buf_size,
|
|
buts->buf_nr, &blk_relay_callbacks, bt);
|
|
if (!bt->rchan)
|
|
goto err;
|
|
|
|
bt->act_mask = buts->act_mask;
|
|
if (!bt->act_mask)
|
|
bt->act_mask = (u16) -1;
|
|
|
|
blk_trace_setup_lba(bt, bdev);
|
|
|
|
/* overwrite with user settings */
|
|
if (buts->start_lba)
|
|
bt->start_lba = buts->start_lba;
|
|
if (buts->end_lba)
|
|
bt->end_lba = buts->end_lba;
|
|
|
|
bt->pid = buts->pid;
|
|
bt->trace_state = Blktrace_setup;
|
|
|
|
rcu_assign_pointer(q->blk_trace, bt);
|
|
get_probe_ref();
|
|
|
|
ret = 0;
|
|
err:
|
|
if (ret)
|
|
blk_trace_free(bt);
|
|
return ret;
|
|
}
|
|
|
|
static int __blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
|
|
struct block_device *bdev, char __user *arg)
|
|
{
|
|
struct blk_user_trace_setup buts;
|
|
int ret;
|
|
|
|
ret = copy_from_user(&buts, arg, sizeof(buts));
|
|
if (ret)
|
|
return -EFAULT;
|
|
|
|
ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (copy_to_user(arg, &buts, sizeof(buts))) {
|
|
__blk_trace_remove(q);
|
|
return -EFAULT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
|
|
struct block_device *bdev,
|
|
char __user *arg)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&q->blk_trace_mutex);
|
|
ret = __blk_trace_setup(q, name, dev, bdev, arg);
|
|
mutex_unlock(&q->blk_trace_mutex);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_trace_setup);
|
|
|
|
#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
|
|
static int compat_blk_trace_setup(struct request_queue *q, char *name,
|
|
dev_t dev, struct block_device *bdev,
|
|
char __user *arg)
|
|
{
|
|
struct blk_user_trace_setup buts;
|
|
struct compat_blk_user_trace_setup cbuts;
|
|
int ret;
|
|
|
|
if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
|
|
return -EFAULT;
|
|
|
|
buts = (struct blk_user_trace_setup) {
|
|
.act_mask = cbuts.act_mask,
|
|
.buf_size = cbuts.buf_size,
|
|
.buf_nr = cbuts.buf_nr,
|
|
.start_lba = cbuts.start_lba,
|
|
.end_lba = cbuts.end_lba,
|
|
.pid = cbuts.pid,
|
|
};
|
|
|
|
ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) {
|
|
__blk_trace_remove(q);
|
|
return -EFAULT;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int __blk_trace_startstop(struct request_queue *q, int start)
|
|
{
|
|
int ret;
|
|
struct blk_trace *bt;
|
|
|
|
bt = rcu_dereference_protected(q->blk_trace,
|
|
lockdep_is_held(&q->blk_trace_mutex));
|
|
if (bt == NULL)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* For starting a trace, we can transition from a setup or stopped
|
|
* trace. For stopping a trace, the state must be running
|
|
*/
|
|
ret = -EINVAL;
|
|
if (start) {
|
|
if (bt->trace_state == Blktrace_setup ||
|
|
bt->trace_state == Blktrace_stopped) {
|
|
blktrace_seq++;
|
|
smp_mb();
|
|
bt->trace_state = Blktrace_running;
|
|
spin_lock_irq(&running_trace_lock);
|
|
list_add(&bt->running_list, &running_trace_list);
|
|
spin_unlock_irq(&running_trace_lock);
|
|
|
|
trace_note_time(bt);
|
|
ret = 0;
|
|
}
|
|
} else {
|
|
if (bt->trace_state == Blktrace_running) {
|
|
bt->trace_state = Blktrace_stopped;
|
|
spin_lock_irq(&running_trace_lock);
|
|
list_del_init(&bt->running_list);
|
|
spin_unlock_irq(&running_trace_lock);
|
|
relay_flush(bt->rchan);
|
|
ret = 0;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int blk_trace_startstop(struct request_queue *q, int start)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&q->blk_trace_mutex);
|
|
ret = __blk_trace_startstop(q, start);
|
|
mutex_unlock(&q->blk_trace_mutex);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_trace_startstop);
|
|
|
|
/*
|
|
* When reading or writing the blktrace sysfs files, the references to the
|
|
* opened sysfs or device files should prevent the underlying block device
|
|
* from being removed. So no further delete protection is really needed.
|
|
*/
|
|
|
|
/**
|
|
* blk_trace_ioctl: - handle the ioctls associated with tracing
|
|
* @bdev: the block device
|
|
* @cmd: the ioctl cmd
|
|
* @arg: the argument data, if any
|
|
*
|
|
**/
|
|
int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
|
|
{
|
|
struct request_queue *q;
|
|
int ret, start = 0;
|
|
char b[BDEVNAME_SIZE];
|
|
|
|
q = bdev_get_queue(bdev);
|
|
if (!q)
|
|
return -ENXIO;
|
|
|
|
mutex_lock(&q->blk_trace_mutex);
|
|
|
|
switch (cmd) {
|
|
case BLKTRACESETUP:
|
|
bdevname(bdev, b);
|
|
ret = __blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
|
|
break;
|
|
#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
|
|
case BLKTRACESETUP32:
|
|
bdevname(bdev, b);
|
|
ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
|
|
break;
|
|
#endif
|
|
case BLKTRACESTART:
|
|
start = 1;
|
|
/* fall through */
|
|
case BLKTRACESTOP:
|
|
ret = __blk_trace_startstop(q, start);
|
|
break;
|
|
case BLKTRACETEARDOWN:
|
|
ret = __blk_trace_remove(q);
|
|
break;
|
|
default:
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
|
|
mutex_unlock(&q->blk_trace_mutex);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* blk_trace_shutdown: - stop and cleanup trace structures
|
|
* @q: the request queue associated with the device
|
|
*
|
|
**/
|
|
void blk_trace_shutdown(struct request_queue *q)
|
|
{
|
|
mutex_lock(&q->blk_trace_mutex);
|
|
if (rcu_dereference_protected(q->blk_trace,
|
|
lockdep_is_held(&q->blk_trace_mutex))) {
|
|
__blk_trace_startstop(q, 0);
|
|
__blk_trace_remove(q);
|
|
}
|
|
|
|
mutex_unlock(&q->blk_trace_mutex);
|
|
}
|
|
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
/* We don't use the 'bt' value here except as an optimization... */
|
|
bt = rcu_dereference_protected(q->blk_trace, 1);
|
|
if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
|
|
return 0;
|
|
|
|
if (!bio->bi_blkg)
|
|
return 0;
|
|
return cgroup_id(bio_blkcg(bio)->css.cgroup);
|
|
}
|
|
#else
|
|
u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static u64
|
|
blk_trace_request_get_cgid(struct request_queue *q, struct request *rq)
|
|
{
|
|
if (!rq->bio)
|
|
return 0;
|
|
/* Use the first bio */
|
|
return blk_trace_bio_get_cgid(q, rq->bio);
|
|
}
|
|
|
|
/*
|
|
* blktrace probes
|
|
*/
|
|
|
|
/**
|
|
* blk_add_trace_rq - Add a trace for a request oriented action
|
|
* @rq: the source request
|
|
* @error: return status to log
|
|
* @nr_bytes: number of completed bytes
|
|
* @what: the action
|
|
* @cgid: the cgroup info
|
|
*
|
|
* Description:
|
|
* Records an action against a request. Will log the bio offset + size.
|
|
*
|
|
**/
|
|
static void blk_add_trace_rq(struct request *rq, int error,
|
|
unsigned int nr_bytes, u32 what, u64 cgid)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(rq->q->blk_trace);
|
|
if (likely(!bt)) {
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
|
|
if (blk_rq_is_passthrough(rq))
|
|
what |= BLK_TC_ACT(BLK_TC_PC);
|
|
else
|
|
what |= BLK_TC_ACT(BLK_TC_FS);
|
|
|
|
__blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
|
|
rq->cmd_flags, what, error, 0, NULL, cgid);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void blk_add_trace_rq_insert(void *ignore,
|
|
struct request_queue *q, struct request *rq)
|
|
{
|
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
|
|
blk_trace_request_get_cgid(q, rq));
|
|
}
|
|
|
|
static void blk_add_trace_rq_issue(void *ignore,
|
|
struct request_queue *q, struct request *rq)
|
|
{
|
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE,
|
|
blk_trace_request_get_cgid(q, rq));
|
|
}
|
|
|
|
static void blk_add_trace_rq_requeue(void *ignore,
|
|
struct request_queue *q,
|
|
struct request *rq)
|
|
{
|
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE,
|
|
blk_trace_request_get_cgid(q, rq));
|
|
}
|
|
|
|
static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
|
|
int error, unsigned int nr_bytes)
|
|
{
|
|
blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE,
|
|
blk_trace_request_get_cgid(rq->q, rq));
|
|
}
|
|
|
|
/**
|
|
* blk_add_trace_bio - Add a trace for a bio oriented action
|
|
* @q: queue the io is for
|
|
* @bio: the source bio
|
|
* @what: the action
|
|
* @error: error, if any
|
|
*
|
|
* Description:
|
|
* Records an action against a bio. Will log the bio offset + size.
|
|
*
|
|
**/
|
|
static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
|
|
u32 what, int error)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (likely(!bt)) {
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
|
|
__blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
|
|
bio_op(bio), bio->bi_opf, what, error, 0, NULL,
|
|
blk_trace_bio_get_cgid(q, bio));
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void blk_add_trace_bio_bounce(void *ignore,
|
|
struct request_queue *q, struct bio *bio)
|
|
{
|
|
blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0);
|
|
}
|
|
|
|
static void blk_add_trace_bio_complete(void *ignore,
|
|
struct request_queue *q, struct bio *bio)
|
|
{
|
|
blk_add_trace_bio(q, bio, BLK_TA_COMPLETE,
|
|
blk_status_to_errno(bio->bi_status));
|
|
}
|
|
|
|
static void blk_add_trace_bio_backmerge(void *ignore,
|
|
struct request_queue *q,
|
|
struct request *rq,
|
|
struct bio *bio)
|
|
{
|
|
blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
|
|
}
|
|
|
|
static void blk_add_trace_bio_frontmerge(void *ignore,
|
|
struct request_queue *q,
|
|
struct request *rq,
|
|
struct bio *bio)
|
|
{
|
|
blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
|
|
}
|
|
|
|
static void blk_add_trace_bio_queue(void *ignore,
|
|
struct request_queue *q, struct bio *bio)
|
|
{
|
|
blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0);
|
|
}
|
|
|
|
static void blk_add_trace_getrq(void *ignore,
|
|
struct request_queue *q,
|
|
struct bio *bio, int rw)
|
|
{
|
|
if (bio)
|
|
blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0);
|
|
else {
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (bt)
|
|
__blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0,
|
|
NULL, 0);
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
|
|
|
|
static void blk_add_trace_sleeprq(void *ignore,
|
|
struct request_queue *q,
|
|
struct bio *bio, int rw)
|
|
{
|
|
if (bio)
|
|
blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0);
|
|
else {
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (bt)
|
|
__blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_SLEEPRQ,
|
|
0, 0, NULL, 0);
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
|
|
static void blk_add_trace_plug(void *ignore, struct request_queue *q)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (bt)
|
|
__blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, 0);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void blk_add_trace_unplug(void *ignore, struct request_queue *q,
|
|
unsigned int depth, bool explicit)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (bt) {
|
|
__be64 rpdu = cpu_to_be64(depth);
|
|
u32 what;
|
|
|
|
if (explicit)
|
|
what = BLK_TA_UNPLUG_IO;
|
|
else
|
|
what = BLK_TA_UNPLUG_TIMER;
|
|
|
|
__blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, 0);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void blk_add_trace_split(void *ignore,
|
|
struct request_queue *q, struct bio *bio,
|
|
unsigned int pdu)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (bt) {
|
|
__be64 rpdu = cpu_to_be64(pdu);
|
|
|
|
__blk_add_trace(bt, bio->bi_iter.bi_sector,
|
|
bio->bi_iter.bi_size, bio_op(bio), bio->bi_opf,
|
|
BLK_TA_SPLIT,
|
|
blk_status_to_errno(bio->bi_status),
|
|
sizeof(rpdu), &rpdu,
|
|
blk_trace_bio_get_cgid(q, bio));
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* blk_add_trace_bio_remap - Add a trace for a bio-remap operation
|
|
* @ignore: trace callback data parameter (not used)
|
|
* @q: queue the io is for
|
|
* @bio: the source bio
|
|
* @dev: target device
|
|
* @from: source sector
|
|
*
|
|
* Description:
|
|
* Device mapper or raid target sometimes need to split a bio because
|
|
* it spans a stripe (or similar). Add a trace for that action.
|
|
*
|
|
**/
|
|
static void blk_add_trace_bio_remap(void *ignore,
|
|
struct request_queue *q, struct bio *bio,
|
|
dev_t dev, sector_t from)
|
|
{
|
|
struct blk_trace *bt;
|
|
struct blk_io_trace_remap r;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (likely(!bt)) {
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
|
|
r.device_from = cpu_to_be32(dev);
|
|
r.device_to = cpu_to_be32(bio_dev(bio));
|
|
r.sector_from = cpu_to_be64(from);
|
|
|
|
__blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
|
|
bio_op(bio), bio->bi_opf, BLK_TA_REMAP,
|
|
blk_status_to_errno(bio->bi_status),
|
|
sizeof(r), &r, blk_trace_bio_get_cgid(q, bio));
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* blk_add_trace_rq_remap - Add a trace for a request-remap operation
|
|
* @ignore: trace callback data parameter (not used)
|
|
* @q: queue the io is for
|
|
* @rq: the source request
|
|
* @dev: target device
|
|
* @from: source sector
|
|
*
|
|
* Description:
|
|
* Device mapper remaps request to other devices.
|
|
* Add a trace for that action.
|
|
*
|
|
**/
|
|
static void blk_add_trace_rq_remap(void *ignore,
|
|
struct request_queue *q,
|
|
struct request *rq, dev_t dev,
|
|
sector_t from)
|
|
{
|
|
struct blk_trace *bt;
|
|
struct blk_io_trace_remap r;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (likely(!bt)) {
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
|
|
r.device_from = cpu_to_be32(dev);
|
|
r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
|
|
r.sector_from = cpu_to_be64(from);
|
|
|
|
__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
|
|
rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
|
|
sizeof(r), &r, blk_trace_request_get_cgid(q, rq));
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* blk_add_driver_data - Add binary message with driver-specific data
|
|
* @q: queue the io is for
|
|
* @rq: io request
|
|
* @data: driver-specific data
|
|
* @len: length of driver-specific data
|
|
*
|
|
* Description:
|
|
* Some drivers might want to write driver-specific data per request.
|
|
*
|
|
**/
|
|
void blk_add_driver_data(struct request_queue *q,
|
|
struct request *rq,
|
|
void *data, size_t len)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
rcu_read_lock();
|
|
bt = rcu_dereference(q->blk_trace);
|
|
if (likely(!bt)) {
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
|
|
__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
|
|
BLK_TA_DRV_DATA, 0, len, data,
|
|
blk_trace_request_get_cgid(q, rq));
|
|
rcu_read_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_add_driver_data);
|
|
|
|
static void blk_register_tracepoints(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_plug(blk_add_trace_plug, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_split(blk_add_trace_split, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
|
|
WARN_ON(ret);
|
|
ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
|
|
WARN_ON(ret);
|
|
}
|
|
|
|
static void blk_unregister_tracepoints(void)
|
|
{
|
|
unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
|
|
unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
|
|
unregister_trace_block_split(blk_add_trace_split, NULL);
|
|
unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
|
|
unregister_trace_block_plug(blk_add_trace_plug, NULL);
|
|
unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
|
|
unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
|
|
unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
|
|
unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
|
|
unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
|
|
unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
|
|
unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
|
|
unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
|
|
unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
|
|
unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
|
|
unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
|
|
|
|
tracepoint_synchronize_unregister();
|
|
}
|
|
|
|
/*
|
|
* struct blk_io_tracer formatting routines
|
|
*/
|
|
|
|
static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
|
|
{
|
|
int i = 0;
|
|
int tc = t->action >> BLK_TC_SHIFT;
|
|
|
|
if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
|
|
rwbs[i++] = 'N';
|
|
goto out;
|
|
}
|
|
|
|
if (tc & BLK_TC_FLUSH)
|
|
rwbs[i++] = 'F';
|
|
|
|
if (tc & BLK_TC_DISCARD)
|
|
rwbs[i++] = 'D';
|
|
else if (tc & BLK_TC_WRITE)
|
|
rwbs[i++] = 'W';
|
|
else if (t->bytes)
|
|
rwbs[i++] = 'R';
|
|
else
|
|
rwbs[i++] = 'N';
|
|
|
|
if (tc & BLK_TC_FUA)
|
|
rwbs[i++] = 'F';
|
|
if (tc & BLK_TC_AHEAD)
|
|
rwbs[i++] = 'A';
|
|
if (tc & BLK_TC_SYNC)
|
|
rwbs[i++] = 'S';
|
|
if (tc & BLK_TC_META)
|
|
rwbs[i++] = 'M';
|
|
out:
|
|
rwbs[i] = '\0';
|
|
}
|
|
|
|
static inline
|
|
const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent)
|
|
{
|
|
return (const struct blk_io_trace *)ent;
|
|
}
|
|
|
|
static inline const void *pdu_start(const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
return (void *)(te_blk_io_trace(ent) + 1) + (has_cg ? sizeof(u64) : 0);
|
|
}
|
|
|
|
static inline u64 t_cgid(const struct trace_entry *ent)
|
|
{
|
|
return *(u64 *)(te_blk_io_trace(ent) + 1);
|
|
}
|
|
|
|
static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
return te_blk_io_trace(ent)->pdu_len - (has_cg ? sizeof(u64) : 0);
|
|
}
|
|
|
|
static inline u32 t_action(const struct trace_entry *ent)
|
|
{
|
|
return te_blk_io_trace(ent)->action;
|
|
}
|
|
|
|
static inline u32 t_bytes(const struct trace_entry *ent)
|
|
{
|
|
return te_blk_io_trace(ent)->bytes;
|
|
}
|
|
|
|
static inline u32 t_sec(const struct trace_entry *ent)
|
|
{
|
|
return te_blk_io_trace(ent)->bytes >> 9;
|
|
}
|
|
|
|
static inline unsigned long long t_sector(const struct trace_entry *ent)
|
|
{
|
|
return te_blk_io_trace(ent)->sector;
|
|
}
|
|
|
|
static inline __u16 t_error(const struct trace_entry *ent)
|
|
{
|
|
return te_blk_io_trace(ent)->error;
|
|
}
|
|
|
|
static __u64 get_pdu_int(const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
const __be64 *val = pdu_start(ent, has_cg);
|
|
return be64_to_cpu(*val);
|
|
}
|
|
|
|
typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act,
|
|
bool has_cg);
|
|
|
|
static void blk_log_action_classic(struct trace_iterator *iter, const char *act,
|
|
bool has_cg)
|
|
{
|
|
char rwbs[RWBS_LEN];
|
|
unsigned long long ts = iter->ts;
|
|
unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
|
|
unsigned secs = (unsigned long)ts;
|
|
const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
|
|
|
|
fill_rwbs(rwbs, t);
|
|
|
|
trace_seq_printf(&iter->seq,
|
|
"%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
|
|
MAJOR(t->device), MINOR(t->device), iter->cpu,
|
|
secs, nsec_rem, iter->ent->pid, act, rwbs);
|
|
}
|
|
|
|
static void blk_log_action(struct trace_iterator *iter, const char *act,
|
|
bool has_cg)
|
|
{
|
|
char rwbs[RWBS_LEN];
|
|
const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
|
|
|
|
fill_rwbs(rwbs, t);
|
|
if (has_cg) {
|
|
u64 id = t_cgid(iter->ent);
|
|
|
|
if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) {
|
|
char blkcg_name_buf[NAME_MAX + 1] = "<...>";
|
|
|
|
cgroup_path_from_kernfs_id(id, blkcg_name_buf,
|
|
sizeof(blkcg_name_buf));
|
|
trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ",
|
|
MAJOR(t->device), MINOR(t->device),
|
|
blkcg_name_buf, act, rwbs);
|
|
} else {
|
|
/*
|
|
* The cgid portion used to be "INO,GEN". Userland
|
|
* builds a FILEID_INO32_GEN fid out of them and
|
|
* opens the cgroup using open_by_handle_at(2).
|
|
* While 32bit ino setups are still the same, 64bit
|
|
* ones now use the 64bit ino as the whole ID and
|
|
* no longer use generation.
|
|
*
|
|
* Regarldess of the content, always output
|
|
* "LOW32,HIGH32" so that FILEID_INO32_GEN fid can
|
|
* be mapped back to @id on both 64 and 32bit ino
|
|
* setups. See __kernfs_fh_to_dentry().
|
|
*/
|
|
trace_seq_printf(&iter->seq,
|
|
"%3d,%-3d %llx,%-llx %2s %3s ",
|
|
MAJOR(t->device), MINOR(t->device),
|
|
id & U32_MAX, id >> 32, act, rwbs);
|
|
}
|
|
} else
|
|
trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
|
|
MAJOR(t->device), MINOR(t->device), act, rwbs);
|
|
}
|
|
|
|
static void blk_log_dump_pdu(struct trace_seq *s,
|
|
const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
const unsigned char *pdu_buf;
|
|
int pdu_len;
|
|
int i, end;
|
|
|
|
pdu_buf = pdu_start(ent, has_cg);
|
|
pdu_len = pdu_real_len(ent, has_cg);
|
|
|
|
if (!pdu_len)
|
|
return;
|
|
|
|
/* find the last zero that needs to be printed */
|
|
for (end = pdu_len - 1; end >= 0; end--)
|
|
if (pdu_buf[end])
|
|
break;
|
|
end++;
|
|
|
|
trace_seq_putc(s, '(');
|
|
|
|
for (i = 0; i < pdu_len; i++) {
|
|
|
|
trace_seq_printf(s, "%s%02x",
|
|
i == 0 ? "" : " ", pdu_buf[i]);
|
|
|
|
/*
|
|
* stop when the rest is just zeroes and indicate so
|
|
* with a ".." appended
|
|
*/
|
|
if (i == end && end != pdu_len - 1) {
|
|
trace_seq_puts(s, " ..) ");
|
|
return;
|
|
}
|
|
}
|
|
|
|
trace_seq_puts(s, ") ");
|
|
}
|
|
|
|
static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
|
|
trace_seq_printf(s, "%u ", t_bytes(ent));
|
|
blk_log_dump_pdu(s, ent, has_cg);
|
|
trace_seq_printf(s, "[%s]\n", cmd);
|
|
} else {
|
|
if (t_sec(ent))
|
|
trace_seq_printf(s, "%llu + %u [%s]\n",
|
|
t_sector(ent), t_sec(ent), cmd);
|
|
else
|
|
trace_seq_printf(s, "[%s]\n", cmd);
|
|
}
|
|
}
|
|
|
|
static void blk_log_with_error(struct trace_seq *s,
|
|
const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
|
|
blk_log_dump_pdu(s, ent, has_cg);
|
|
trace_seq_printf(s, "[%d]\n", t_error(ent));
|
|
} else {
|
|
if (t_sec(ent))
|
|
trace_seq_printf(s, "%llu + %u [%d]\n",
|
|
t_sector(ent),
|
|
t_sec(ent), t_error(ent));
|
|
else
|
|
trace_seq_printf(s, "%llu [%d]\n",
|
|
t_sector(ent), t_error(ent));
|
|
}
|
|
}
|
|
|
|
static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
const struct blk_io_trace_remap *__r = pdu_start(ent, has_cg);
|
|
|
|
trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
|
|
t_sector(ent), t_sec(ent),
|
|
MAJOR(be32_to_cpu(__r->device_from)),
|
|
MINOR(be32_to_cpu(__r->device_from)),
|
|
be64_to_cpu(__r->sector_from));
|
|
}
|
|
|
|
static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
trace_seq_printf(s, "[%s]\n", cmd);
|
|
}
|
|
|
|
static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent, has_cg));
|
|
}
|
|
|
|
static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
|
|
get_pdu_int(ent, has_cg), cmd);
|
|
}
|
|
|
|
static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent,
|
|
bool has_cg)
|
|
{
|
|
|
|
trace_seq_putmem(s, pdu_start(ent, has_cg),
|
|
pdu_real_len(ent, has_cg));
|
|
trace_seq_putc(s, '\n');
|
|
}
|
|
|
|
/*
|
|
* struct tracer operations
|
|
*/
|
|
|
|
static void blk_tracer_print_header(struct seq_file *m)
|
|
{
|
|
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
|
|
return;
|
|
seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n"
|
|
"# | | | | | |\n");
|
|
}
|
|
|
|
static void blk_tracer_start(struct trace_array *tr)
|
|
{
|
|
blk_tracer_enabled = true;
|
|
}
|
|
|
|
static int blk_tracer_init(struct trace_array *tr)
|
|
{
|
|
blk_tr = tr;
|
|
blk_tracer_start(tr);
|
|
return 0;
|
|
}
|
|
|
|
static void blk_tracer_stop(struct trace_array *tr)
|
|
{
|
|
blk_tracer_enabled = false;
|
|
}
|
|
|
|
static void blk_tracer_reset(struct trace_array *tr)
|
|
{
|
|
blk_tracer_stop(tr);
|
|
}
|
|
|
|
static const struct {
|
|
const char *act[2];
|
|
void (*print)(struct trace_seq *s, const struct trace_entry *ent,
|
|
bool has_cg);
|
|
} what2act[] = {
|
|
[__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
|
|
[__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
|
|
[__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic },
|
|
[__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic },
|
|
[__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic },
|
|
[__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error },
|
|
[__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic },
|
|
[__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error },
|
|
[__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug },
|
|
[__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug },
|
|
[__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug },
|
|
[__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic },
|
|
[__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split },
|
|
[__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
|
|
[__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
|
|
};
|
|
|
|
static enum print_line_t print_one_line(struct trace_iterator *iter,
|
|
bool classic)
|
|
{
|
|
struct trace_array *tr = iter->tr;
|
|
struct trace_seq *s = &iter->seq;
|
|
const struct blk_io_trace *t;
|
|
u16 what;
|
|
bool long_act;
|
|
blk_log_action_t *log_action;
|
|
bool has_cg;
|
|
|
|
t = te_blk_io_trace(iter->ent);
|
|
what = (t->action & ((1 << BLK_TC_SHIFT) - 1)) & ~__BLK_TA_CGROUP;
|
|
long_act = !!(tr->trace_flags & TRACE_ITER_VERBOSE);
|
|
log_action = classic ? &blk_log_action_classic : &blk_log_action;
|
|
has_cg = t->action & __BLK_TA_CGROUP;
|
|
|
|
if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
|
|
log_action(iter, long_act ? "message" : "m", has_cg);
|
|
blk_log_msg(s, iter->ent, has_cg);
|
|
return trace_handle_return(s);
|
|
}
|
|
|
|
if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
|
|
trace_seq_printf(s, "Unknown action %x\n", what);
|
|
else {
|
|
log_action(iter, what2act[what].act[long_act], has_cg);
|
|
what2act[what].print(s, iter->ent, has_cg);
|
|
}
|
|
|
|
return trace_handle_return(s);
|
|
}
|
|
|
|
static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
|
|
int flags, struct trace_event *event)
|
|
{
|
|
return print_one_line(iter, false);
|
|
}
|
|
|
|
static void blk_trace_synthesize_old_trace(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
|
|
const int offset = offsetof(struct blk_io_trace, sector);
|
|
struct blk_io_trace old = {
|
|
.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
|
|
.time = iter->ts,
|
|
};
|
|
|
|
trace_seq_putmem(s, &old, offset);
|
|
trace_seq_putmem(s, &t->sector,
|
|
sizeof(old) - offset + t->pdu_len);
|
|
}
|
|
|
|
static enum print_line_t
|
|
blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
|
|
struct trace_event *event)
|
|
{
|
|
blk_trace_synthesize_old_trace(iter);
|
|
|
|
return trace_handle_return(&iter->seq);
|
|
}
|
|
|
|
static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
|
|
{
|
|
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
|
|
return TRACE_TYPE_UNHANDLED;
|
|
|
|
return print_one_line(iter, true);
|
|
}
|
|
|
|
static int
|
|
blk_tracer_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
|
|
{
|
|
/* don't output context-info for blk_classic output */
|
|
if (bit == TRACE_BLK_OPT_CLASSIC) {
|
|
if (set)
|
|
tr->trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
|
|
else
|
|
tr->trace_flags |= TRACE_ITER_CONTEXT_INFO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct tracer blk_tracer __read_mostly = {
|
|
.name = "blk",
|
|
.init = blk_tracer_init,
|
|
.reset = blk_tracer_reset,
|
|
.start = blk_tracer_start,
|
|
.stop = blk_tracer_stop,
|
|
.print_header = blk_tracer_print_header,
|
|
.print_line = blk_tracer_print_line,
|
|
.flags = &blk_tracer_flags,
|
|
.set_flag = blk_tracer_set_flag,
|
|
};
|
|
|
|
static struct trace_event_functions trace_blk_event_funcs = {
|
|
.trace = blk_trace_event_print,
|
|
.binary = blk_trace_event_print_binary,
|
|
};
|
|
|
|
static struct trace_event trace_blk_event = {
|
|
.type = TRACE_BLK,
|
|
.funcs = &trace_blk_event_funcs,
|
|
};
|
|
|
|
static int __init init_blk_tracer(void)
|
|
{
|
|
if (!register_trace_event(&trace_blk_event)) {
|
|
pr_warn("Warning: could not register block events\n");
|
|
return 1;
|
|
}
|
|
|
|
if (register_tracer(&blk_tracer) != 0) {
|
|
pr_warn("Warning: could not register the block tracer\n");
|
|
unregister_trace_event(&trace_blk_event);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(init_blk_tracer);
|
|
|
|
static int blk_trace_remove_queue(struct request_queue *q)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
bt = rcu_replace_pointer(q->blk_trace, NULL,
|
|
lockdep_is_held(&q->blk_trace_mutex));
|
|
if (bt == NULL)
|
|
return -EINVAL;
|
|
|
|
put_probe_ref();
|
|
synchronize_rcu();
|
|
blk_trace_free(bt);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Setup everything required to start tracing
|
|
*/
|
|
static int blk_trace_setup_queue(struct request_queue *q,
|
|
struct block_device *bdev)
|
|
{
|
|
struct blk_trace *bt = NULL;
|
|
int ret = -ENOMEM;
|
|
|
|
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
|
|
if (!bt)
|
|
return -ENOMEM;
|
|
|
|
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
|
|
if (!bt->msg_data)
|
|
goto free_bt;
|
|
|
|
bt->dev = bdev->bd_dev;
|
|
bt->act_mask = (u16)-1;
|
|
|
|
blk_trace_setup_lba(bt, bdev);
|
|
|
|
rcu_assign_pointer(q->blk_trace, bt);
|
|
get_probe_ref();
|
|
return 0;
|
|
|
|
free_bt:
|
|
blk_trace_free(bt);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* sysfs interface to enable and configure tracing
|
|
*/
|
|
|
|
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf);
|
|
static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count);
|
|
#define BLK_TRACE_DEVICE_ATTR(_name) \
|
|
DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
|
|
sysfs_blk_trace_attr_show, \
|
|
sysfs_blk_trace_attr_store)
|
|
|
|
static BLK_TRACE_DEVICE_ATTR(enable);
|
|
static BLK_TRACE_DEVICE_ATTR(act_mask);
|
|
static BLK_TRACE_DEVICE_ATTR(pid);
|
|
static BLK_TRACE_DEVICE_ATTR(start_lba);
|
|
static BLK_TRACE_DEVICE_ATTR(end_lba);
|
|
|
|
static struct attribute *blk_trace_attrs[] = {
|
|
&dev_attr_enable.attr,
|
|
&dev_attr_act_mask.attr,
|
|
&dev_attr_pid.attr,
|
|
&dev_attr_start_lba.attr,
|
|
&dev_attr_end_lba.attr,
|
|
NULL
|
|
};
|
|
|
|
struct attribute_group blk_trace_attr_group = {
|
|
.name = "trace",
|
|
.attrs = blk_trace_attrs,
|
|
};
|
|
|
|
static const struct {
|
|
int mask;
|
|
const char *str;
|
|
} mask_maps[] = {
|
|
{ BLK_TC_READ, "read" },
|
|
{ BLK_TC_WRITE, "write" },
|
|
{ BLK_TC_FLUSH, "flush" },
|
|
{ BLK_TC_SYNC, "sync" },
|
|
{ BLK_TC_QUEUE, "queue" },
|
|
{ BLK_TC_REQUEUE, "requeue" },
|
|
{ BLK_TC_ISSUE, "issue" },
|
|
{ BLK_TC_COMPLETE, "complete" },
|
|
{ BLK_TC_FS, "fs" },
|
|
{ BLK_TC_PC, "pc" },
|
|
{ BLK_TC_NOTIFY, "notify" },
|
|
{ BLK_TC_AHEAD, "ahead" },
|
|
{ BLK_TC_META, "meta" },
|
|
{ BLK_TC_DISCARD, "discard" },
|
|
{ BLK_TC_DRV_DATA, "drv_data" },
|
|
{ BLK_TC_FUA, "fua" },
|
|
};
|
|
|
|
static int blk_trace_str2mask(const char *str)
|
|
{
|
|
int i;
|
|
int mask = 0;
|
|
char *buf, *s, *token;
|
|
|
|
buf = kstrdup(str, GFP_KERNEL);
|
|
if (buf == NULL)
|
|
return -ENOMEM;
|
|
s = strstrip(buf);
|
|
|
|
while (1) {
|
|
token = strsep(&s, ",");
|
|
if (token == NULL)
|
|
break;
|
|
|
|
if (*token == '\0')
|
|
continue;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
|
|
if (strcasecmp(token, mask_maps[i].str) == 0) {
|
|
mask |= mask_maps[i].mask;
|
|
break;
|
|
}
|
|
}
|
|
if (i == ARRAY_SIZE(mask_maps)) {
|
|
mask = -EINVAL;
|
|
break;
|
|
}
|
|
}
|
|
kfree(buf);
|
|
|
|
return mask;
|
|
}
|
|
|
|
static ssize_t blk_trace_mask2str(char *buf, int mask)
|
|
{
|
|
int i;
|
|
char *p = buf;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
|
|
if (mask & mask_maps[i].mask) {
|
|
p += sprintf(p, "%s%s",
|
|
(p == buf) ? "" : ",", mask_maps[i].str);
|
|
}
|
|
}
|
|
*p++ = '\n';
|
|
|
|
return p - buf;
|
|
}
|
|
|
|
static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
|
|
{
|
|
if (bdev->bd_disk == NULL)
|
|
return NULL;
|
|
|
|
return bdev_get_queue(bdev);
|
|
}
|
|
|
|
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct hd_struct *p = dev_to_part(dev);
|
|
struct request_queue *q;
|
|
struct block_device *bdev;
|
|
struct blk_trace *bt;
|
|
ssize_t ret = -ENXIO;
|
|
|
|
bdev = bdget(part_devt(p));
|
|
if (bdev == NULL)
|
|
goto out;
|
|
|
|
q = blk_trace_get_queue(bdev);
|
|
if (q == NULL)
|
|
goto out_bdput;
|
|
|
|
mutex_lock(&q->blk_trace_mutex);
|
|
|
|
bt = rcu_dereference_protected(q->blk_trace,
|
|
lockdep_is_held(&q->blk_trace_mutex));
|
|
if (attr == &dev_attr_enable) {
|
|
ret = sprintf(buf, "%u\n", !!bt);
|
|
goto out_unlock_bdev;
|
|
}
|
|
|
|
if (bt == NULL)
|
|
ret = sprintf(buf, "disabled\n");
|
|
else if (attr == &dev_attr_act_mask)
|
|
ret = blk_trace_mask2str(buf, bt->act_mask);
|
|
else if (attr == &dev_attr_pid)
|
|
ret = sprintf(buf, "%u\n", bt->pid);
|
|
else if (attr == &dev_attr_start_lba)
|
|
ret = sprintf(buf, "%llu\n", bt->start_lba);
|
|
else if (attr == &dev_attr_end_lba)
|
|
ret = sprintf(buf, "%llu\n", bt->end_lba);
|
|
|
|
out_unlock_bdev:
|
|
mutex_unlock(&q->blk_trace_mutex);
|
|
out_bdput:
|
|
bdput(bdev);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct block_device *bdev;
|
|
struct request_queue *q;
|
|
struct hd_struct *p;
|
|
struct blk_trace *bt;
|
|
u64 value;
|
|
ssize_t ret = -EINVAL;
|
|
|
|
if (count == 0)
|
|
goto out;
|
|
|
|
if (attr == &dev_attr_act_mask) {
|
|
if (kstrtoull(buf, 0, &value)) {
|
|
/* Assume it is a list of trace category names */
|
|
ret = blk_trace_str2mask(buf);
|
|
if (ret < 0)
|
|
goto out;
|
|
value = ret;
|
|
}
|
|
} else if (kstrtoull(buf, 0, &value))
|
|
goto out;
|
|
|
|
ret = -ENXIO;
|
|
|
|
p = dev_to_part(dev);
|
|
bdev = bdget(part_devt(p));
|
|
if (bdev == NULL)
|
|
goto out;
|
|
|
|
q = blk_trace_get_queue(bdev);
|
|
if (q == NULL)
|
|
goto out_bdput;
|
|
|
|
mutex_lock(&q->blk_trace_mutex);
|
|
|
|
bt = rcu_dereference_protected(q->blk_trace,
|
|
lockdep_is_held(&q->blk_trace_mutex));
|
|
if (attr == &dev_attr_enable) {
|
|
if (!!value == !!bt) {
|
|
ret = 0;
|
|
goto out_unlock_bdev;
|
|
}
|
|
if (value)
|
|
ret = blk_trace_setup_queue(q, bdev);
|
|
else
|
|
ret = blk_trace_remove_queue(q);
|
|
goto out_unlock_bdev;
|
|
}
|
|
|
|
ret = 0;
|
|
if (bt == NULL) {
|
|
ret = blk_trace_setup_queue(q, bdev);
|
|
bt = rcu_dereference_protected(q->blk_trace,
|
|
lockdep_is_held(&q->blk_trace_mutex));
|
|
}
|
|
|
|
if (ret == 0) {
|
|
if (attr == &dev_attr_act_mask)
|
|
bt->act_mask = value;
|
|
else if (attr == &dev_attr_pid)
|
|
bt->pid = value;
|
|
else if (attr == &dev_attr_start_lba)
|
|
bt->start_lba = value;
|
|
else if (attr == &dev_attr_end_lba)
|
|
bt->end_lba = value;
|
|
}
|
|
|
|
out_unlock_bdev:
|
|
mutex_unlock(&q->blk_trace_mutex);
|
|
out_bdput:
|
|
bdput(bdev);
|
|
out:
|
|
return ret ? ret : count;
|
|
}
|
|
|
|
int blk_trace_init_sysfs(struct device *dev)
|
|
{
|
|
return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
|
|
}
|
|
|
|
void blk_trace_remove_sysfs(struct device *dev)
|
|
{
|
|
sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
|
|
}
|
|
|
|
#endif /* CONFIG_BLK_DEV_IO_TRACE */
|
|
|
|
#ifdef CONFIG_EVENT_TRACING
|
|
|
|
void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes)
|
|
{
|
|
int i = 0;
|
|
|
|
if (op & REQ_PREFLUSH)
|
|
rwbs[i++] = 'F';
|
|
|
|
switch (op & REQ_OP_MASK) {
|
|
case REQ_OP_WRITE:
|
|
case REQ_OP_WRITE_SAME:
|
|
rwbs[i++] = 'W';
|
|
break;
|
|
case REQ_OP_DISCARD:
|
|
rwbs[i++] = 'D';
|
|
break;
|
|
case REQ_OP_SECURE_ERASE:
|
|
rwbs[i++] = 'D';
|
|
rwbs[i++] = 'E';
|
|
break;
|
|
case REQ_OP_FLUSH:
|
|
rwbs[i++] = 'F';
|
|
break;
|
|
case REQ_OP_READ:
|
|
rwbs[i++] = 'R';
|
|
break;
|
|
default:
|
|
rwbs[i++] = 'N';
|
|
}
|
|
|
|
if (op & REQ_FUA)
|
|
rwbs[i++] = 'F';
|
|
if (op & REQ_RAHEAD)
|
|
rwbs[i++] = 'A';
|
|
if (op & REQ_SYNC)
|
|
rwbs[i++] = 'S';
|
|
if (op & REQ_META)
|
|
rwbs[i++] = 'M';
|
|
|
|
rwbs[i] = '\0';
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_fill_rwbs);
|
|
|
|
#endif /* CONFIG_EVENT_TRACING */
|
|
|