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1928 lines
46 KiB
1928 lines
46 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2006 Jens Axboe <[email protected]> |
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* |
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*/ |
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|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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|
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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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unsigned int trace_ctx = 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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trace_ctx = tracing_gen_ctx_flags(0); |
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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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trace_ctx); |
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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, trace_ctx); |
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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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|
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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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unsigned int trace_ctx = 0; |
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pid_t pid; |
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int cpu; |
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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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trace_ctx = tracing_gen_ctx_flags(0); |
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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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trace_ctx); |
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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, trace_ctx); |
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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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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); |
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kfree(bt); |
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} |
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static void get_probe_ref(void) |
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{ |
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mutex_lock(&blk_probe_mutex); |
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if (++blk_probes_ref == 1) |
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blk_register_tracepoints(); |
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mutex_unlock(&blk_probe_mutex); |
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} |
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static void put_probe_ref(void) |
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{ |
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mutex_lock(&blk_probe_mutex); |
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if (!--blk_probes_ref) |
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blk_unregister_tracepoints(); |
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mutex_unlock(&blk_probe_mutex); |
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} |
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static void blk_trace_cleanup(struct blk_trace *bt) |
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{ |
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synchronize_rcu(); |
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blk_trace_free(bt); |
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put_probe_ref(); |
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} |
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static int __blk_trace_remove(struct request_queue *q) |
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{ |
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struct blk_trace *bt; |
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bt = rcu_replace_pointer(q->blk_trace, NULL, |
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lockdep_is_held(&q->debugfs_mutex)); |
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if (!bt) |
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return -EINVAL; |
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|
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if (bt->trace_state != Blktrace_running) |
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blk_trace_cleanup(bt); |
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return 0; |
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} |
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int blk_trace_remove(struct request_queue *q) |
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{ |
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int ret; |
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mutex_lock(&q->debugfs_mutex); |
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ret = __blk_trace_remove(q); |
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mutex_unlock(&q->debugfs_mutex); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(blk_trace_remove); |
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static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, |
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size_t count, loff_t *ppos) |
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{ |
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struct blk_trace *bt = filp->private_data; |
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char buf[16]; |
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|
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snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); |
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return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); |
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} |
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static const struct file_operations blk_dropped_fops = { |
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.owner = THIS_MODULE, |
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.open = simple_open, |
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.read = blk_dropped_read, |
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.llseek = default_llseek, |
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}; |
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|
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static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, |
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size_t count, loff_t *ppos) |
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{ |
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char *msg; |
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struct blk_trace *bt; |
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|
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if (count >= BLK_TN_MAX_MSG) |
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return -EINVAL; |
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msg = memdup_user_nul(buffer, count); |
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if (IS_ERR(msg)) |
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return PTR_ERR(msg); |
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|
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bt = filp->private_data; |
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__trace_note_message(bt, NULL, "%s", msg); |
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kfree(msg); |
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|
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return count; |
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} |
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static const struct file_operations blk_msg_fops = { |
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.owner = THIS_MODULE, |
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.open = simple_open, |
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.write = blk_msg_write, |
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.llseek = noop_llseek, |
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}; |
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|
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/* |
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* Keep track of how many times we encountered a full subbuffer, to aid |
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* the user space app in telling how many lost events there were. |
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*/ |
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static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, |
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void *prev_subbuf, size_t prev_padding) |
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{ |
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struct blk_trace *bt; |
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|
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if (!relay_buf_full(buf)) |
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return 1; |
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|
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bt = buf->chan->private_data; |
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atomic_inc(&bt->dropped); |
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return 0; |
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} |
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|
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static int blk_remove_buf_file_callback(struct dentry *dentry) |
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{ |
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debugfs_remove(dentry); |
|
|
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return 0; |
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} |
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|
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static struct dentry *blk_create_buf_file_callback(const char *filename, |
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struct dentry *parent, |
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umode_t mode, |
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struct rchan_buf *buf, |
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int *is_global) |
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{ |
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return debugfs_create_file(filename, mode, parent, buf, |
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&relay_file_operations); |
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} |
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|
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static const struct rchan_callbacks blk_relay_callbacks = { |
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.subbuf_start = blk_subbuf_start_callback, |
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.create_buf_file = blk_create_buf_file_callback, |
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.remove_buf_file = blk_remove_buf_file_callback, |
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}; |
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|
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static void blk_trace_setup_lba(struct blk_trace *bt, |
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struct block_device *bdev) |
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{ |
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if (bdev) { |
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bt->start_lba = bdev->bd_start_sect; |
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bt->end_lba = bdev->bd_start_sect + bdev_nr_sectors(bdev); |
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} else { |
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bt->start_lba = 0; |
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bt->end_lba = -1ULL; |
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} |
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} |
|
|
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/* |
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* Setup everything required to start tracing |
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*/ |
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static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
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struct block_device *bdev, |
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struct blk_user_trace_setup *buts) |
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{ |
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struct blk_trace *bt = NULL; |
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struct dentry *dir = NULL; |
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int ret; |
|
|
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lockdep_assert_held(&q->debugfs_mutex); |
|
|
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if (!buts->buf_size || !buts->buf_nr) |
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return -EINVAL; |
|
|
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strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); |
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buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; |
|
|
|
/* |
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* some device names have larger paths - convert the slashes |
|
* to underscores for this to work as expected |
|
*/ |
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strreplace(buts->name, '/', '_'); |
|
|
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/* |
|
* bdev can be NULL, as with scsi-generic, this is a helpful as |
|
* we can be. |
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*/ |
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if (rcu_dereference_protected(q->blk_trace, |
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lockdep_is_held(&q->debugfs_mutex))) { |
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pr_warn("Concurrent blktraces are not allowed on %s\n", |
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buts->name); |
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return -EBUSY; |
|
} |
|
|
|
bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
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if (!bt) |
|
return -ENOMEM; |
|
|
|
ret = -ENOMEM; |
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bt->sequence = alloc_percpu(unsigned long); |
|
if (!bt->sequence) |
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goto err; |
|
|
|
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
|
if (!bt->msg_data) |
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goto err; |
|
|
|
/* |
|
* When tracing the whole disk reuse the existing debugfs directory |
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* created by the block layer on init. For partitions block devices, |
|
* and scsi-generic block devices we create a temporary new debugfs |
|
* directory that will be removed once the trace ends. |
|
*/ |
|
if (bdev && !bdev_is_partition(bdev)) |
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dir = q->debugfs_dir; |
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else |
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bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); |
|
|
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/* |
|
* As blktrace relies on debugfs for its interface the debugfs directory |
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* is required, contrary to the usual mantra of not checking for debugfs |
|
* files or directories. |
|
*/ |
|
if (IS_ERR_OR_NULL(dir)) { |
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pr_warn("debugfs_dir not present for %s so skipping\n", |
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buts->name); |
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ret = -ENOENT; |
|
goto err; |
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} |
|
|
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bt->dev = dev; |
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atomic_set(&bt->dropped, 0); |
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INIT_LIST_HEAD(&bt->running_list); |
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|
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ret = -EIO; |
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debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops); |
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debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); |
|
|
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bt->rchan = relay_open("trace", dir, buts->buf_size, |
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buts->buf_nr, &blk_relay_callbacks, bt); |
|
if (!bt->rchan) |
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goto err; |
|
|
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bt->act_mask = buts->act_mask; |
|
if (!bt->act_mask) |
|
bt->act_mask = (u16) -1; |
|
|
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blk_trace_setup_lba(bt, bdev); |
|
|
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/* overwrite with user settings */ |
|
if (buts->start_lba) |
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bt->start_lba = buts->start_lba; |
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if (buts->end_lba) |
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bt->end_lba = buts->end_lba; |
|
|
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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->debugfs_mutex); |
|
ret = __blk_trace_setup(q, name, dev, bdev, arg); |
|
mutex_unlock(&q->debugfs_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->debugfs_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->debugfs_mutex); |
|
ret = __blk_trace_startstop(q, start); |
|
mutex_unlock(&q->debugfs_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->debugfs_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; |
|
fallthrough; |
|
case BLKTRACESTOP: |
|
ret = __blk_trace_startstop(q, start); |
|
break; |
|
case BLKTRACETEARDOWN: |
|
ret = __blk_trace_remove(q); |
|
break; |
|
default: |
|
ret = -ENOTTY; |
|
break; |
|
} |
|
|
|
mutex_unlock(&q->debugfs_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->debugfs_mutex); |
|
if (rcu_dereference_protected(q->blk_trace, |
|
lockdep_is_held(&q->debugfs_mutex))) { |
|
__blk_trace_startstop(q, 0); |
|
__blk_trace_remove(q); |
|
} |
|
|
|
mutex_unlock(&q->debugfs_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 |
|
static 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 *rq) |
|
{ |
|
if (!rq->bio) |
|
return 0; |
|
/* Use the first bio */ |
|
return blk_trace_bio_get_cgid(rq->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 *rq) |
|
{ |
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT, |
|
blk_trace_request_get_cgid(rq)); |
|
} |
|
|
|
static void blk_add_trace_rq_issue(void *ignore, struct request *rq) |
|
{ |
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE, |
|
blk_trace_request_get_cgid(rq)); |
|
} |
|
|
|
static void blk_add_trace_rq_merge(void *ignore, struct request *rq) |
|
{ |
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE, |
|
blk_trace_request_get_cgid(rq)); |
|
} |
|
|
|
static void blk_add_trace_rq_requeue(void *ignore, struct request *rq) |
|
{ |
|
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE, |
|
blk_trace_request_get_cgid(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)); |
|
} |
|
|
|
/** |
|
* 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 bio *bio) |
|
{ |
|
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, 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 bio *bio) |
|
{ |
|
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_BACKMERGE, |
|
0); |
|
} |
|
|
|
static void blk_add_trace_bio_frontmerge(void *ignore, struct bio *bio) |
|
{ |
|
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_FRONTMERGE, |
|
0); |
|
} |
|
|
|
static void blk_add_trace_bio_queue(void *ignore, struct bio *bio) |
|
{ |
|
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_QUEUE, 0); |
|
} |
|
|
|
static void blk_add_trace_getrq(void *ignore, struct bio *bio) |
|
{ |
|
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_GETRQ, 0); |
|
} |
|
|
|
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 bio *bio, unsigned int pdu) |
|
{ |
|
struct request_queue *q = bio->bi_bdev->bd_disk->queue; |
|
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) |
|
* @bio: the source bio |
|
* @dev: source device |
|
* @from: source sector |
|
* |
|
* Called after a bio is remapped to a different device and/or sector. |
|
**/ |
|
static void blk_add_trace_bio_remap(void *ignore, struct bio *bio, dev_t dev, |
|
sector_t from) |
|
{ |
|
struct request_queue *q = bio->bi_bdev->bd_disk->queue; |
|
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) |
|
* @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 *rq, dev_t dev, |
|
sector_t from) |
|
{ |
|
struct blk_trace *bt; |
|
struct blk_io_trace_remap r; |
|
|
|
rcu_read_lock(); |
|
bt = rcu_dereference(rq->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(rq)); |
|
rcu_read_unlock(); |
|
} |
|
|
|
/** |
|
* blk_add_driver_data - Add binary message with driver-specific data |
|
* @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 *rq, void *data, size_t len) |
|
{ |
|
struct blk_trace *bt; |
|
|
|
rcu_read_lock(); |
|
bt = rcu_dereference(rq->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(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_merge(blk_add_trace_rq_merge, 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_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_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_merge(blk_add_trace_rq_merge, 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. |
|
* |
|
* Regardless 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 zeros 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->debugfs_mutex)); |
|
if (bt == NULL) |
|
return -EINVAL; |
|
|
|
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); |
|
} |
|
|
|
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 ssize_t sysfs_blk_trace_attr_show(struct device *dev, |
|
struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
struct block_device *bdev = dev_to_bdev(dev); |
|
struct request_queue *q = bdev_get_queue(bdev); |
|
struct blk_trace *bt; |
|
ssize_t ret = -ENXIO; |
|
|
|
mutex_lock(&q->debugfs_mutex); |
|
|
|
bt = rcu_dereference_protected(q->blk_trace, |
|
lockdep_is_held(&q->debugfs_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->debugfs_mutex); |
|
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 = dev_to_bdev(dev); |
|
struct request_queue *q = bdev_get_queue(bdev); |
|
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; |
|
} |
|
|
|
mutex_lock(&q->debugfs_mutex); |
|
|
|
bt = rcu_dereference_protected(q->blk_trace, |
|
lockdep_is_held(&q->debugfs_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->debugfs_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->debugfs_mutex); |
|
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 |
|
|
|
/** |
|
* blk_fill_rwbs - Fill the buffer rwbs by mapping op to character string. |
|
* @rwbs: buffer to be filled |
|
* @op: REQ_OP_XXX for the tracepoint |
|
* |
|
* Description: |
|
* Maps the REQ_OP_XXX to character and fills the buffer provided by the |
|
* caller with resulting string. |
|
* |
|
**/ |
|
void blk_fill_rwbs(char *rwbs, unsigned int op) |
|
{ |
|
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 */ |
|
|
|
|