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@@ -24,15 +24,32 @@
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#include <linux/debugfs.h>
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#include <linux/time.h>
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#include <trace/block.h>
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-#include <asm/uaccess.h>
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+#include <linux/uaccess.h>
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+#include "trace_output.h"
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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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+
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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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+
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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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+ { }
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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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+
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/* Global reference count of probes */
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-static DEFINE_MUTEX(blk_probe_mutex);
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static atomic_t blk_probes_ref = ATOMIC_INIT(0);
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-static int blk_register_tracepoints(void);
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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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@@ -42,19 +59,39 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
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const void *data, size_t len)
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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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+ 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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+
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+ if (blk_tracer) {
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+ pc = preempt_count();
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+ event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK,
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+ sizeof(*t) + 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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+
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+ if (!bt->rchan)
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+ return;
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t = relay_reserve(bt->rchan, sizeof(*t) + len);
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if (t) {
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- const int cpu = smp_processor_id();
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-
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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;
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t->pid = pid;
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t->cpu = cpu;
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t->pdu_len = len;
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memcpy((void *) t + sizeof(*t), data, len);
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+
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+ if (blk_tracer)
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+ trace_buffer_unlock_commit(blk_tr, event, 0, pc);
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}
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}
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@@ -90,6 +127,10 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
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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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local_irq_save(flags);
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buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
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va_start(args, fmt);
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@@ -117,11 +158,12 @@ static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
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/*
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* Data direction bit lookup
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*/
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-static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) };
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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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/* The ilog2() calls fall out because they're constant */
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-#define MASK_TC_BIT(rw, __name) ( (rw & (1 << BIO_RW_ ## __name)) << \
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- (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name) )
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+#define MASK_TC_BIT(rw, __name) ((rw & (1 << BIO_RW_ ## __name)) << \
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+ (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __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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@@ -131,13 +173,15 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
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int rw, u32 what, int error, int pdu_len, void *pdu_data)
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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 blk_io_trace *t;
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- unsigned long flags;
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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;
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+ int cpu, pc = 0;
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+ bool blk_tracer = blk_tracer_enabled;
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- if (unlikely(bt->trace_state != Blktrace_running))
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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[rw & WRITE];
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@@ -150,6 +194,20 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
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pid = tsk->pid;
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if (unlikely(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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+
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+ if (blk_tracer) {
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+ tracing_record_cmdline(current);
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+
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+ pc = preempt_count();
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+ event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK,
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+ sizeof(*t) + pdu_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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/*
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* A word about the locking here - we disable interrupts to reserve
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@@ -163,23 +221,35 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
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t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len);
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if (t) {
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- cpu = smp_processor_id();
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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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+
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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->pid = pid;
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t->device = bt->dev;
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- t->cpu = cpu;
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t->error = error;
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t->pdu_len = pdu_len;
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if (pdu_len)
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memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
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+
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+ if (blk_tracer) {
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+ trace_buffer_unlock_commit(blk_tr, 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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@@ -188,7 +258,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
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static struct dentry *blk_tree_root;
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static DEFINE_MUTEX(blk_tree_mutex);
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-static void blk_trace_cleanup(struct blk_trace *bt)
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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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@@ -196,10 +266,13 @@ static void blk_trace_cleanup(struct blk_trace *bt)
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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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- mutex_lock(&blk_probe_mutex);
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+}
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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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+ blk_trace_free(bt);
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if (atomic_dec_and_test(&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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int blk_trace_remove(struct request_queue *q)
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@@ -210,8 +283,7 @@ int blk_trace_remove(struct request_queue *q)
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if (!bt)
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return -EINVAL;
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- if (bt->trace_state == Blktrace_setup ||
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- bt->trace_state == Blktrace_stopped)
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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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@@ -354,11 +426,11 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
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if (buts->name[i] == '/')
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buts->name[i] = '_';
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- ret = -ENOMEM;
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bt = kzalloc(sizeof(*bt), GFP_KERNEL);
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if (!bt)
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- goto err;
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+ return -ENOMEM;
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+ ret = -ENOMEM;
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bt->sequence = alloc_percpu(unsigned long);
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if (!bt->sequence)
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goto err;
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@@ -369,11 +441,15 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
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ret = -ENOENT;
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+ mutex_lock(&blk_tree_mutex);
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if (!blk_tree_root) {
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blk_tree_root = debugfs_create_dir("block", NULL);
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- if (!blk_tree_root)
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- return -ENOMEM;
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+ if (!blk_tree_root) {
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+ mutex_unlock(&blk_tree_mutex);
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+ goto err;
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+ }
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}
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+ mutex_unlock(&blk_tree_mutex);
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dir = debugfs_create_dir(buts->name, blk_tree_root);
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@@ -385,7 +461,8 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
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atomic_set(&bt->dropped, 0);
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ret = -EIO;
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- bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
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+ bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
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+ &blk_dropped_fops);
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if (!bt->dropped_file)
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goto err;
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@@ -410,14 +487,6 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
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bt->pid = buts->pid;
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bt->trace_state = Blktrace_setup;
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- mutex_lock(&blk_probe_mutex);
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- if (atomic_add_return(1, &blk_probes_ref) == 1) {
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- ret = blk_register_tracepoints();
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- if (ret)
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- goto probe_err;
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- }
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- mutex_unlock(&blk_probe_mutex);
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-
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ret = -EBUSY;
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old_bt = xchg(&q->blk_trace, bt);
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if (old_bt) {
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@@ -425,22 +494,12 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
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goto err;
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}
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+ if (atomic_inc_return(&blk_probes_ref) == 1)
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+ blk_register_tracepoints();
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+
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return 0;
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-probe_err:
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- atomic_dec(&blk_probes_ref);
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- mutex_unlock(&blk_probe_mutex);
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err:
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- if (bt) {
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- if (bt->msg_file)
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- debugfs_remove(bt->msg_file);
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- if (bt->dropped_file)
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- debugfs_remove(bt->dropped_file);
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- free_percpu(bt->sequence);
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- free_percpu(bt->msg_data);
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- if (bt->rchan)
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- relay_close(bt->rchan);
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- kfree(bt);
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- }
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+ blk_trace_free(bt);
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return ret;
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}
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@@ -467,10 +526,10 @@ EXPORT_SYMBOL_GPL(blk_trace_setup);
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int blk_trace_startstop(struct request_queue *q, int start)
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{
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- struct blk_trace *bt;
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int ret;
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+ struct blk_trace *bt = q->blk_trace;
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- if ((bt = q->blk_trace) == NULL)
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+ if (bt == NULL)
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return -EINVAL;
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/*
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@@ -503,7 +562,7 @@ EXPORT_SYMBOL_GPL(blk_trace_startstop);
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/**
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* blk_trace_ioctl: - handle the ioctls associated with tracing
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* @bdev: the block device
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- * @cmd: the ioctl cmd
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+ * @cmd: the ioctl cmd
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* @arg: the argument data, if any
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*
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**/
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@@ -606,12 +665,14 @@ static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq)
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blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
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}
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-static void blk_add_trace_rq_requeue(struct request_queue *q, struct request *rq)
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+static void blk_add_trace_rq_requeue(struct request_queue *q,
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+ struct request *rq)
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{
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blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
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}
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-static void blk_add_trace_rq_complete(struct request_queue *q, struct request *rq)
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+static void blk_add_trace_rq_complete(struct request_queue *q,
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+ struct request *rq)
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{
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blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
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}
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@@ -648,12 +709,14 @@ static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio)
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blk_add_trace_bio(q, bio, BLK_TA_COMPLETE);
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}
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-static void blk_add_trace_bio_backmerge(struct request_queue *q, struct bio *bio)
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+static void blk_add_trace_bio_backmerge(struct request_queue *q,
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+ struct bio *bio)
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{
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blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
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}
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-static void blk_add_trace_bio_frontmerge(struct request_queue *q, struct bio *bio)
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+static void blk_add_trace_bio_frontmerge(struct request_queue *q,
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+ struct bio *bio)
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{
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blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
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}
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@@ -663,7 +726,8 @@ static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio)
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blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
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}
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-static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw)
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+static void blk_add_trace_getrq(struct request_queue *q,
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+ struct bio *bio, int rw)
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{
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if (bio)
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blk_add_trace_bio(q, bio, BLK_TA_GETRQ);
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@@ -676,7 +740,8 @@ static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw
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}
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-static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int rw)
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+static void blk_add_trace_sleeprq(struct request_queue *q,
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+ struct bio *bio, int rw)
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{
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if (bio)
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blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ);
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@@ -684,7 +749,8 @@ static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int
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struct blk_trace *bt = q->blk_trace;
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if (bt)
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- __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, 0, 0, NULL);
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+ __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ,
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+ 0, 0, NULL);
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}
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}
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@@ -795,7 +861,7 @@ void blk_add_driver_data(struct request_queue *q,
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}
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EXPORT_SYMBOL_GPL(blk_add_driver_data);
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-static int blk_register_tracepoints(void)
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|
|
+static void blk_register_tracepoints(void)
|
|
|
{
|
|
|
int ret;
|
|
|
|
|
@@ -833,7 +899,6 @@ static int blk_register_tracepoints(void)
|
|
|
WARN_ON(ret);
|
|
|
ret = register_trace_block_remap(blk_add_trace_remap);
|
|
|
WARN_ON(ret);
|
|
|
- return 0;
|
|
|
}
|
|
|
|
|
|
static void blk_unregister_tracepoints(void)
|
|
@@ -858,3 +923,627 @@ static void blk_unregister_tracepoints(void)
|
|
|
|
|
|
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_MESSAGE) {
|
|
|
+ rwbs[i++] = 'N';
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+
|
|
|
+ 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_AHEAD)
|
|
|
+ rwbs[i++] = 'A';
|
|
|
+ if (tc & BLK_TC_BARRIER)
|
|
|
+ rwbs[i++] = 'B';
|
|
|
+ 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)
|
|
|
+{
|
|
|
+ return te_blk_io_trace(ent) + 1;
|
|
|
+}
|
|
|
+
|
|
|
+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)
|
|
|
+{
|
|
|
+ const __u64 *val = pdu_start(ent);
|
|
|
+ return be64_to_cpu(*val);
|
|
|
+}
|
|
|
+
|
|
|
+static void get_pdu_remap(const struct trace_entry *ent,
|
|
|
+ struct blk_io_trace_remap *r)
|
|
|
+{
|
|
|
+ const struct blk_io_trace_remap *__r = pdu_start(ent);
|
|
|
+ __u64 sector = __r->sector;
|
|
|
+
|
|
|
+ r->device = be32_to_cpu(__r->device);
|
|
|
+ r->device_from = be32_to_cpu(__r->device_from);
|
|
|
+ r->sector = be64_to_cpu(sector);
|
|
|
+}
|
|
|
+
|
|
|
+typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
|
|
|
+
|
|
|
+static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
|
|
|
+{
|
|
|
+ char rwbs[6];
|
|
|
+ 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);
|
|
|
+
|
|
|
+ return 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 int blk_log_action(struct trace_iterator *iter, const char *act)
|
|
|
+{
|
|
|
+ char rwbs[6];
|
|
|
+ const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
|
|
|
+
|
|
|
+ fill_rwbs(rwbs, t);
|
|
|
+ return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
|
|
|
+ MAJOR(t->device), MINOR(t->device), act, rwbs);
|
|
|
+}
|
|
|
+
|
|
|
+static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
|
|
|
+{
|
|
|
+ char cmd[TASK_COMM_LEN];
|
|
|
+
|
|
|
+ trace_find_cmdline(ent->pid, cmd);
|
|
|
+
|
|
|
+ if (t_sec(ent))
|
|
|
+ return trace_seq_printf(s, "%llu + %u [%s]\n",
|
|
|
+ t_sector(ent), t_sec(ent), cmd);
|
|
|
+ return trace_seq_printf(s, "[%s]\n", cmd);
|
|
|
+}
|
|
|
+
|
|
|
+static int blk_log_with_error(struct trace_seq *s,
|
|
|
+ const struct trace_entry *ent)
|
|
|
+{
|
|
|
+ if (t_sec(ent))
|
|
|
+ return trace_seq_printf(s, "%llu + %u [%d]\n", t_sector(ent),
|
|
|
+ t_sec(ent), t_error(ent));
|
|
|
+ return trace_seq_printf(s, "%llu [%d]\n", t_sector(ent), t_error(ent));
|
|
|
+}
|
|
|
+
|
|
|
+static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
|
|
|
+{
|
|
|
+ struct blk_io_trace_remap r = { .device = 0, };
|
|
|
+
|
|
|
+ get_pdu_remap(ent, &r);
|
|
|
+ return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
|
|
|
+ t_sector(ent),
|
|
|
+ t_sec(ent), MAJOR(r.device), MINOR(r.device),
|
|
|
+ (unsigned long long)r.sector);
|
|
|
+}
|
|
|
+
|
|
|
+static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
|
|
|
+{
|
|
|
+ char cmd[TASK_COMM_LEN];
|
|
|
+
|
|
|
+ trace_find_cmdline(ent->pid, cmd);
|
|
|
+
|
|
|
+ return trace_seq_printf(s, "[%s]\n", cmd);
|
|
|
+}
|
|
|
+
|
|
|
+static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
|
|
|
+{
|
|
|
+ char cmd[TASK_COMM_LEN];
|
|
|
+
|
|
|
+ trace_find_cmdline(ent->pid, cmd);
|
|
|
+
|
|
|
+ return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
|
|
|
+}
|
|
|
+
|
|
|
+static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
|
|
|
+{
|
|
|
+ char cmd[TASK_COMM_LEN];
|
|
|
+
|
|
|
+ trace_find_cmdline(ent->pid, cmd);
|
|
|
+
|
|
|
+ return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
|
|
|
+ get_pdu_int(ent), cmd);
|
|
|
+}
|
|
|
+
|
|
|
+static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
|
|
|
+{
|
|
|
+ int ret;
|
|
|
+ const struct blk_io_trace *t = te_blk_io_trace(ent);
|
|
|
+
|
|
|
+ ret = trace_seq_putmem(s, t + 1, t->pdu_len);
|
|
|
+ if (ret)
|
|
|
+ return trace_seq_putc(s, '\n');
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * 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;
|
|
|
+ trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
|
|
|
+}
|
|
|
+
|
|
|
+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;
|
|
|
+ trace_flags |= TRACE_ITER_CONTEXT_INFO;
|
|
|
+}
|
|
|
+
|
|
|
+static void blk_tracer_reset(struct trace_array *tr)
|
|
|
+{
|
|
|
+ blk_tracer_stop(tr);
|
|
|
+}
|
|
|
+
|
|
|
+static const struct {
|
|
|
+ const char *act[2];
|
|
|
+ int (*print)(struct trace_seq *s, const struct trace_entry *ent);
|
|
|
+} 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_seq *s = &iter->seq;
|
|
|
+ const struct blk_io_trace *t;
|
|
|
+ u16 what;
|
|
|
+ int ret;
|
|
|
+ bool long_act;
|
|
|
+ blk_log_action_t *log_action;
|
|
|
+
|
|
|
+ t = te_blk_io_trace(iter->ent);
|
|
|
+ what = t->action & ((1 << BLK_TC_SHIFT) - 1);
|
|
|
+ long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
|
|
|
+ log_action = classic ? &blk_log_action_classic : &blk_log_action;
|
|
|
+
|
|
|
+ if (t->action == BLK_TN_MESSAGE) {
|
|
|
+ ret = log_action(iter, long_act ? "message" : "m");
|
|
|
+ if (ret)
|
|
|
+ ret = blk_log_msg(s, iter->ent);
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
|
|
|
+ ret = trace_seq_printf(s, "Bad pc action %x\n", what);
|
|
|
+ else {
|
|
|
+ ret = log_action(iter, what2act[what].act[long_act]);
|
|
|
+ if (ret)
|
|
|
+ ret = what2act[what].print(s, iter->ent);
|
|
|
+ }
|
|
|
+out:
|
|
|
+ return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
|
|
|
+}
|
|
|
+
|
|
|
+static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
|
|
|
+ int flags)
|
|
|
+{
|
|
|
+ if (!trace_print_context(iter))
|
|
|
+ return TRACE_TYPE_PARTIAL_LINE;
|
|
|
+
|
|
|
+ return print_one_line(iter, false);
|
|
|
+}
|
|
|
+
|
|
|
+static int 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,
|
|
|
+ };
|
|
|
+
|
|
|
+ if (!trace_seq_putmem(s, &old, offset))
|
|
|
+ return 0;
|
|
|
+ return 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)
|
|
|
+{
|
|
|
+ return blk_trace_synthesize_old_trace(iter) ?
|
|
|
+ TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
|
|
|
+}
|
|
|
+
|
|
|
+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 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,
|
|
|
+};
|
|
|
+
|
|
|
+static struct trace_event trace_blk_event = {
|
|
|
+ .type = TRACE_BLK,
|
|
|
+ .trace = blk_trace_event_print,
|
|
|
+ .binary = blk_trace_event_print_binary,
|
|
|
+};
|
|
|
+
|
|
|
+static int __init init_blk_tracer(void)
|
|
|
+{
|
|
|
+ if (!register_ftrace_event(&trace_blk_event)) {
|
|
|
+ pr_warning("Warning: could not register block events\n");
|
|
|
+ return 1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (register_tracer(&blk_tracer) != 0) {
|
|
|
+ pr_warning("Warning: could not register the block tracer\n");
|
|
|
+ unregister_ftrace_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 = xchg(&q->blk_trace, NULL);
|
|
|
+ if (bt == NULL)
|
|
|
+ return -EINVAL;
|
|
|
+
|
|
|
+ if (atomic_dec_and_test(&blk_probes_ref))
|
|
|
+ blk_unregister_tracepoints();
|
|
|
+
|
|
|
+ blk_trace_free(bt);
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Setup everything required to start tracing
|
|
|
+ */
|
|
|
+static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)
|
|
|
+{
|
|
|
+ struct blk_trace *old_bt, *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 = dev;
|
|
|
+ bt->act_mask = (u16)-1;
|
|
|
+ bt->end_lba = -1ULL;
|
|
|
+
|
|
|
+ old_bt = xchg(&q->blk_trace, bt);
|
|
|
+ if (old_bt != NULL) {
|
|
|
+ (void)xchg(&q->blk_trace, old_bt);
|
|
|
+ ret = -EBUSY;
|
|
|
+ goto free_bt;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (atomic_inc_return(&blk_probes_ref) == 1)
|
|
|
+ blk_register_tracepoints();
|
|
|
+ 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_BARRIER, "barrier" },
|
|
|
+ { 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_AHEAD, "ahead" },
|
|
|
+ { BLK_TC_META, "meta" },
|
|
|
+ { BLK_TC_DISCARD, "discard" },
|
|
|
+ { BLK_TC_DRV_DATA, "drv_data" },
|
|
|
+};
|
|
|
+
|
|
|
+static int blk_trace_str2mask(const char *str)
|
|
|
+{
|
|
|
+ int i;
|
|
|
+ int mask = 0;
|
|
|
+ char *s, *token;
|
|
|
+
|
|
|
+ s = kstrdup(str, GFP_KERNEL);
|
|
|
+ if (s == NULL)
|
|
|
+ return -ENOMEM;
|
|
|
+ s = strstrip(s);
|
|
|
+
|
|
|
+ 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(s);
|
|
|
+
|
|
|
+ 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;
|
|
|
+ ssize_t ret = -ENXIO;
|
|
|
+
|
|
|
+ lock_kernel();
|
|
|
+ bdev = bdget(part_devt(p));
|
|
|
+ if (bdev == NULL)
|
|
|
+ goto out_unlock_kernel;
|
|
|
+
|
|
|
+ q = blk_trace_get_queue(bdev);
|
|
|
+ if (q == NULL)
|
|
|
+ goto out_bdput;
|
|
|
+
|
|
|
+ mutex_lock(&bdev->bd_mutex);
|
|
|
+
|
|
|
+ if (attr == &dev_attr_enable) {
|
|
|
+ ret = sprintf(buf, "%u\n", !!q->blk_trace);
|
|
|
+ goto out_unlock_bdev;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (q->blk_trace == NULL)
|
|
|
+ ret = sprintf(buf, "disabled\n");
|
|
|
+ else if (attr == &dev_attr_act_mask)
|
|
|
+ ret = blk_trace_mask2str(buf, q->blk_trace->act_mask);
|
|
|
+ else if (attr == &dev_attr_pid)
|
|
|
+ ret = sprintf(buf, "%u\n", q->blk_trace->pid);
|
|
|
+ else if (attr == &dev_attr_start_lba)
|
|
|
+ ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
|
|
|
+ else if (attr == &dev_attr_end_lba)
|
|
|
+ ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
|
|
|
+
|
|
|
+out_unlock_bdev:
|
|
|
+ mutex_unlock(&bdev->bd_mutex);
|
|
|
+out_bdput:
|
|
|
+ bdput(bdev);
|
|
|
+out_unlock_kernel:
|
|
|
+ unlock_kernel();
|
|
|
+ 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;
|
|
|
+ u64 value;
|
|
|
+ ssize_t ret = -EINVAL;
|
|
|
+
|
|
|
+ if (count == 0)
|
|
|
+ goto out;
|
|
|
+
|
|
|
+ if (attr == &dev_attr_act_mask) {
|
|
|
+ if (sscanf(buf, "%llx", &value) != 1) {
|
|
|
+ /* Assume it is a list of trace category names */
|
|
|
+ ret = blk_trace_str2mask(buf);
|
|
|
+ if (ret < 0)
|
|
|
+ goto out;
|
|
|
+ value = ret;
|
|
|
+ }
|
|
|
+ } else if (sscanf(buf, "%llu", &value) != 1)
|
|
|
+ goto out;
|
|
|
+
|
|
|
+ ret = -ENXIO;
|
|
|
+
|
|
|
+ lock_kernel();
|
|
|
+ p = dev_to_part(dev);
|
|
|
+ bdev = bdget(part_devt(p));
|
|
|
+ if (bdev == NULL)
|
|
|
+ goto out_unlock_kernel;
|
|
|
+
|
|
|
+ q = blk_trace_get_queue(bdev);
|
|
|
+ if (q == NULL)
|
|
|
+ goto out_bdput;
|
|
|
+
|
|
|
+ mutex_lock(&bdev->bd_mutex);
|
|
|
+
|
|
|
+ if (attr == &dev_attr_enable) {
|
|
|
+ if (value)
|
|
|
+ ret = blk_trace_setup_queue(q, bdev->bd_dev);
|
|
|
+ else
|
|
|
+ ret = blk_trace_remove_queue(q);
|
|
|
+ goto out_unlock_bdev;
|
|
|
+ }
|
|
|
+
|
|
|
+ ret = 0;
|
|
|
+ if (q->blk_trace == NULL)
|
|
|
+ ret = blk_trace_setup_queue(q, bdev->bd_dev);
|
|
|
+
|
|
|
+ if (ret == 0) {
|
|
|
+ if (attr == &dev_attr_act_mask)
|
|
|
+ q->blk_trace->act_mask = value;
|
|
|
+ else if (attr == &dev_attr_pid)
|
|
|
+ q->blk_trace->pid = value;
|
|
|
+ else if (attr == &dev_attr_start_lba)
|
|
|
+ q->blk_trace->start_lba = value;
|
|
|
+ else if (attr == &dev_attr_end_lba)
|
|
|
+ q->blk_trace->end_lba = value;
|
|
|
+ }
|
|
|
+
|
|
|
+out_unlock_bdev:
|
|
|
+ mutex_unlock(&bdev->bd_mutex);
|
|
|
+out_bdput:
|
|
|
+ bdput(bdev);
|
|
|
+out_unlock_kernel:
|
|
|
+ unlock_kernel();
|
|
|
+out:
|
|
|
+ return ret ? ret : count;
|
|
|
+}
|
|
|
+
|