static unsigned int blktrace_seq __read_mostly = 1;
static struct trace_array *blk_tr;
-static int __read_mostly blk_tracer_enabled;
+static bool blk_tracer_enabled __read_mostly;
/* Select an alternative, minimalistic output than the original one */
-#define TRACE_BLK_OPT_CLASSIC 0x1
+#define TRACE_BLK_OPT_CLASSIC 0x1
static struct tracer_opt blk_tracer_opts[] = {
/* Default disable the minimalistic output */
};
/* Global reference count of probes */
-static DEFINE_MUTEX(blk_probe_mutex);
static atomic_t blk_probes_ref = ATOMIC_INIT(0);
-static int blk_register_tracepoints(void);
+static void blk_register_tracepoints(void);
static void blk_unregister_tracepoints(void);
/*
unsigned long flags;
char *buf;
- if (blk_tr) {
+ if (blk_tracer_enabled) {
va_start(args, fmt);
ftrace_vprintk(fmt, args);
va_end(args);
/*
* Data direction bit lookup
*/
-static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ),
- BLK_TC_ACT(BLK_TC_WRITE) };
+static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
+ BLK_TC_ACT(BLK_TC_WRITE) };
/* The ilog2() calls fall out because they're constant */
#define MASK_TC_BIT(rw, __name) ((rw & (1 << BIO_RW_ ## __name)) << \
pid_t pid;
int cpu, pc = 0;
- if (unlikely(bt->trace_state != Blktrace_running ||
+ if (unlikely(bt->trace_state != Blktrace_running &&
!blk_tracer_enabled))
return;
return;
cpu = raw_smp_processor_id();
- if (blk_tr) {
+ if (blk_tracer_enabled) {
tracing_record_cmdline(current);
pc = preempt_count();
if (pdu_len)
memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
- if (blk_tr) {
+ if (blk_tracer_enabled) {
trace_buffer_unlock_commit(blk_tr, event, 0, pc);
return;
}
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
kfree(bt);
- mutex_lock(&blk_probe_mutex);
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
- mutex_unlock(&blk_probe_mutex);
}
int blk_trace_remove(struct request_queue *q)
if (!bt)
return -EINVAL;
- if (bt->trace_state == Blktrace_setup ||
- bt->trace_state == Blktrace_stopped)
+ if (bt->trace_state != Blktrace_running)
blk_trace_cleanup(bt);
return 0;
ret = -ENOENT;
+ mutex_lock(&blk_tree_mutex);
if (!blk_tree_root) {
blk_tree_root = debugfs_create_dir("block", NULL);
- if (!blk_tree_root)
- return -ENOMEM;
+ if (!blk_tree_root) {
+ mutex_unlock(&blk_tree_mutex);
+ goto err;
+ }
}
+ mutex_unlock(&blk_tree_mutex);
dir = debugfs_create_dir(buts->name, blk_tree_root);
bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;
- mutex_lock(&blk_probe_mutex);
- if (atomic_add_return(1, &blk_probes_ref) == 1) {
- ret = blk_register_tracepoints();
- if (ret)
- goto probe_err;
- }
- mutex_unlock(&blk_probe_mutex);
-
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
goto err;
}
+ if (atomic_add_return(1, &blk_probes_ref) == 1)
+ blk_register_tracepoints();
+
return 0;
-probe_err:
- atomic_dec(&blk_probes_ref);
- mutex_unlock(&blk_probe_mutex);
err:
if (bt) {
if (bt->msg_file)
/**
* blk_trace_ioctl: - handle the ioctls associated with tracing
* @bdev: the block device
- * @cmd: the ioctl cmd
+ * @cmd: the ioctl cmd
* @arg: the argument data, if any
*
**/
}
EXPORT_SYMBOL_GPL(blk_add_driver_data);
-static int blk_register_tracepoints(void)
+static void blk_register_tracepoints(void)
{
int ret;
WARN_ON(ret);
ret = register_trace_block_remap(blk_add_trace_remap);
WARN_ON(ret);
- return 0;
}
static void blk_unregister_tracepoints(void)
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_TC_DISCARD)
+ if (tc & BLK_TC_DISCARD)
rwbs[i++] = 'D';
- else if (t->action & BLK_TC_WRITE)
+ else if (tc & BLK_TC_WRITE)
rwbs[i++] = 'W';
else if (t->bytes)
rwbs[i++] = 'R';
else
rwbs[i++] = 'N';
- if (t->action & BLK_TC_AHEAD)
+ if (tc & BLK_TC_AHEAD)
rwbs[i++] = 'A';
- if (t->action & BLK_TC_BARRIER)
+ if (tc & BLK_TC_BARRIER)
rwbs[i++] = 'B';
- if (t->action & BLK_TC_SYNC)
+ if (tc & BLK_TC_SYNC)
rwbs[i++] = 'S';
- if (t->action & BLK_TC_META)
+ if (tc & BLK_TC_META)
rwbs[i++] = 'M';
rwbs[i] = '\0';
static inline __u16 t_error(const struct trace_entry *ent)
{
- return te_blk_io_trace(ent)->sector;
+ return te_blk_io_trace(ent)->error;
}
static __u64 get_pdu_int(const struct trace_entry *ent)
static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
{
- const char *cmd = trace_find_cmdline(ent->pid);
+ char cmd[TASK_COMM_LEN];
+
+ trace_find_cmdline(ent->pid, cmd);
if (t_sec(ent))
return trace_seq_printf(s, "%llu + %u [%s]\n",
static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
{
- return trace_seq_printf(s, "[%s]\n", trace_find_cmdline(ent->pid));
+ 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)
{
- return trace_seq_printf(s, "[%s] %llu\n", trace_find_cmdline(ent->pid),
- get_pdu_int(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), trace_find_cmdline(ent->pid));
+ get_pdu_int(ent), cmd);
}
/*
static void blk_tracer_start(struct trace_array *tr)
{
- mutex_lock(&blk_probe_mutex);
if (atomic_add_return(1, &blk_probes_ref) == 1)
- if (blk_register_tracepoints())
- atomic_dec(&blk_probes_ref);
- mutex_unlock(&blk_probe_mutex);
+ blk_register_tracepoints();
trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
}
{
blk_tr = tr;
blk_tracer_start(tr);
- mutex_lock(&blk_probe_mutex);
- blk_tracer_enabled++;
- mutex_unlock(&blk_probe_mutex);
+ blk_tracer_enabled = true;
return 0;
}
static void blk_tracer_stop(struct trace_array *tr)
{
trace_flags |= TRACE_ITER_CONTEXT_INFO;
- mutex_lock(&blk_probe_mutex);
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
- mutex_unlock(&blk_probe_mutex);
}
static void blk_tracer_reset(struct trace_array *tr)
if (!atomic_read(&blk_probes_ref))
return;
- mutex_lock(&blk_probe_mutex);
- blk_tracer_enabled--;
- WARN_ON(blk_tracer_enabled < 0);
- mutex_unlock(&blk_probe_mutex);
-
+ blk_tracer_enabled = false;
blk_tracer_stop(tr);
}
-static struct {
+static const struct {
const char *act[2];
- int (*print)(struct trace_seq *s, const struct trace_entry *ent);
-} what2act[] __read_mostly = {
- [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
+ 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 },
const int offset = offsetof(struct blk_io_trace, sector);
struct blk_io_trace old = {
.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
- .time = ns2usecs(iter->ts),
+ .time = iter->ts,
};
if (!trace_seq_putmem(s, &old, offset))
};
static struct trace_event trace_blk_event = {
- .type = TRACE_BLK,
+ .type = TRACE_BLK,
.trace = blk_trace_event_print,
.binary = blk_trace_event_print_binary,
};
static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)
{
struct blk_trace *old_bt, *bt = NULL;
- int ret;
- ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
- goto err;
+ return -ENOMEM;
bt->dev = dev;
bt->act_mask = (u16)-1;
bt->end_lba = -1ULL;
- bt->trace_state = Blktrace_running;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt != NULL) {
(void)xchg(&q->blk_trace, old_bt);
kfree(bt);
- ret = -EBUSY;
+ return -EBUSY;
}
+
return 0;
-err:
- return ret;
}
/*
* sysfs interface to enable and configure tracing
*/
-static ssize_t sysfs_blk_trace_enable_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct hd_struct *p = dev_to_part(dev);
- struct block_device *bdev;
- ssize_t ret = -ENXIO;
-
- lock_kernel();
- bdev = bdget(part_devt(p));
- if (bdev != NULL) {
- struct request_queue *q = bdev_get_queue(bdev);
-
- if (q != NULL) {
- mutex_lock(&bdev->bd_mutex);
- ret = sprintf(buf, "%u\n", !!q->blk_trace);
- mutex_unlock(&bdev->bd_mutex);
- }
-
- bdput(bdev);
- }
-
- unlock_kernel();
- return ret;
-}
-
-static ssize_t sysfs_blk_trace_enable_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;
- int value;
- ssize_t ret = -ENXIO;
-
- if (count == 0 || sscanf(buf, "%d", &value) != 1)
- goto out;
-
- lock_kernel();
- p = dev_to_part(dev);
- bdev = bdget(part_devt(p));
- if (bdev == NULL)
- goto out_unlock_kernel;
-
- q = bdev_get_queue(bdev);
- if (q == NULL)
- goto out_bdput;
-
- mutex_lock(&bdev->bd_mutex);
- if (value)
- ret = blk_trace_setup_queue(q, bdev->bd_dev);
- else
- ret = blk_trace_remove_queue(q);
- mutex_unlock(&bdev->bd_mutex);
-
- if (ret == 0)
- ret = count;
-out_bdput:
- bdput(bdev);
-out_unlock_kernel:
- unlock_kernel();
-out:
- return ret;
-}
-
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
struct device_attribute *attr,
char *buf);
sysfs_blk_trace_attr_show, \
sysfs_blk_trace_attr_store)
-static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
- sysfs_blk_trace_enable_show, sysfs_blk_trace_enable_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);
.attrs = blk_trace_attrs,
};
-static int blk_str2act_mask(const char *str)
+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 *copy = kstrdup(str, GFP_KERNEL), *s;
+ char *s, *token;
- if (copy == NULL)
+ s = kstrdup(str, GFP_KERNEL);
+ if (s == NULL)
return -ENOMEM;
-
- s = strstrip(copy);
+ s = strstrip(s);
while (1) {
- char *sep = strchr(s, ',');
-
- if (sep != NULL)
- *sep = '\0';
-
- if (strcasecmp(s, "barrier") == 0)
- mask |= BLK_TC_BARRIER;
- else if (strcasecmp(s, "complete") == 0)
- mask |= BLK_TC_COMPLETE;
- else if (strcasecmp(s, "fs") == 0)
- mask |= BLK_TC_FS;
- else if (strcasecmp(s, "issue") == 0)
- mask |= BLK_TC_ISSUE;
- else if (strcasecmp(s, "pc") == 0)
- mask |= BLK_TC_PC;
- else if (strcasecmp(s, "queue") == 0)
- mask |= BLK_TC_QUEUE;
- else if (strcasecmp(s, "read") == 0)
- mask |= BLK_TC_READ;
- else if (strcasecmp(s, "requeue") == 0)
- mask |= BLK_TC_REQUEUE;
- else if (strcasecmp(s, "sync") == 0)
- mask |= BLK_TC_SYNC;
- else if (strcasecmp(s, "write") == 0)
- mask |= BLK_TC_WRITE;
-
- if (sep == NULL)
+ token = strsep(&s, ",");
+ if (token == NULL)
break;
- s = sep + 1;
+ 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(copy);
+ 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)
if (bdev == NULL)
goto out_unlock_kernel;
- q = bdev_get_queue(bdev);
+ 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 = sprintf(buf, "%#x\n", q->blk_trace->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);
struct request_queue *q;
struct hd_struct *p;
u64 value;
- ssize_t ret = -ENXIO;
+ 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 */
- value = blk_str2act_mask(buf);
- if (value < 0)
+ 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 = bdev_get_queue(bdev);
+ 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);
q->blk_trace->start_lba = value;
else if (attr == &dev_attr_end_lba)
q->blk_trace->end_lba = value;
- ret = count;
}
+
+out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
out_unlock_kernel:
unlock_kernel();
out:
- return ret;
+ return ret ? ret : count;
}
+