#include <linux/time.h>
#include <asm/uaccess.h>
-static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, };
static unsigned int blktrace_seq __read_mostly = 1;
/*
const int cpu = smp_processor_id();
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
- t->time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu);
+ t->time = ktime_to_ns(ktime_get());
t->device = bt->dev;
t->action = action;
t->pid = pid;
local_irq_restore(flags);
}
+void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
+{
+ int n;
+ va_list args;
+ unsigned long flags;
+ char *buf;
+
+ local_irq_save(flags);
+ buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
+ va_start(args, fmt);
+ n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
+ va_end(args);
+
+ trace_note(bt, 0, BLK_TN_MESSAGE, buf, n);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(__trace_note_message);
+
static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
pid_t pid)
{
*/
static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) };
-/*
- * Bio action bits of interest
- */
-static u32 bio_act[9] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD), 0, 0, 0, BLK_TC_ACT(BLK_TC_META) };
-
-/*
- * More could be added as needed, taking care to increment the decrementer
- * to get correct indexing
- */
-#define trace_barrier_bit(rw) \
- (((rw) & (1 << BIO_RW_BARRIER)) >> (BIO_RW_BARRIER - 0))
-#define trace_sync_bit(rw) \
- (((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1))
-#define trace_ahead_bit(rw) \
- (((rw) & (1 << BIO_RW_AHEAD)) << (2 - BIO_RW_AHEAD))
-#define trace_meta_bit(rw) \
- (((rw) & (1 << BIO_RW_META)) >> (BIO_RW_META - 3))
+/* The ilog2() calls fall out because they're constant */
+#define MASK_TC_BIT(rw, __name) ( (rw & (1 << BIO_RW_ ## __name)) << \
+ (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name) )
/*
* The worker for the various blk_add_trace*() types. Fills out a
return;
what |= ddir_act[rw & WRITE];
- what |= bio_act[trace_barrier_bit(rw)];
- what |= bio_act[trace_sync_bit(rw)];
- what |= bio_act[trace_ahead_bit(rw)];
- what |= bio_act[trace_meta_bit(rw)];
+ what |= MASK_TC_BIT(rw, BARRIER);
+ what |= MASK_TC_BIT(rw, SYNC);
+ what |= MASK_TC_BIT(rw, AHEAD);
+ what |= MASK_TC_BIT(rw, META);
+ what |= MASK_TC_BIT(rw, DISCARD);
pid = tsk->pid;
if (unlikely(act_log_check(bt, what, sector, pid)))
/*
* A word about the locking here - we disable interrupts to reserve
* some space in the relay per-cpu buffer, to prevent an irq
- * from coming in and stepping on our toes. Once reserved, it's
- * enough to get preemption disabled to prevent read of this data
- * before we are through filling it. get_cpu()/put_cpu() does this
- * for us
+ * from coming in and stepping on our toes.
*/
local_irq_save(flags);
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
t->sequence = ++(*sequence);
- t->time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu);
+ t->time = ktime_to_ns(ktime_get());
t->sector = sector;
t->bytes = bytes;
t->action = what;
EXPORT_SYMBOL_GPL(__blk_add_trace);
static struct dentry *blk_tree_root;
-static struct mutex blk_tree_mutex;
+static DEFINE_MUTEX(blk_tree_mutex);
static unsigned int root_users;
static inline void blk_remove_root(void)
static struct dentry *blk_create_tree(const char *blk_name)
{
struct dentry *dir = NULL;
+ int created = 0;
mutex_lock(&blk_tree_mutex);
blk_tree_root = debugfs_create_dir("block", NULL);
if (!blk_tree_root)
goto err;
+ created = 1;
}
dir = debugfs_create_dir(blk_name, blk_tree_root);
if (dir)
root_users++;
- else
- blk_remove_root();
+ else {
+ /* Delete root only if we created it */
+ if (created)
+ blk_remove_root();
+ }
err:
mutex_unlock(&blk_tree_mutex);
static void blk_trace_cleanup(struct blk_trace *bt)
{
relay_close(bt->rchan);
+ debugfs_remove(bt->msg_file);
debugfs_remove(bt->dropped_file);
blk_remove_tree(bt->dir);
free_percpu(bt->sequence);
+ free_percpu(bt->msg_data);
kfree(bt);
}
-static int blk_trace_remove(request_queue_t *q)
+int blk_trace_remove(struct request_queue *q)
{
struct blk_trace *bt;
return 0;
}
+EXPORT_SYMBOL_GPL(blk_trace_remove);
static int blk_dropped_open(struct inode *inode, struct file *filp)
{
.read = blk_dropped_read,
};
+static int blk_msg_open(struct inode *inode, struct file *filp)
+{
+ filp->private_data = inode->i_private;
+
+ return 0;
+}
+
+static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ char *msg;
+ struct blk_trace *bt;
+
+ if (count > BLK_TN_MAX_MSG)
+ return -EINVAL;
+
+ msg = kmalloc(count, GFP_KERNEL);
+ if (msg == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(msg, buffer, count)) {
+ kfree(msg);
+ return -EFAULT;
+ }
+
+ bt = filp->private_data;
+ __trace_note_message(bt, "%s", msg);
+ kfree(msg);
+
+ return count;
+}
+
+static const struct file_operations blk_msg_fops = {
+ .owner = THIS_MODULE,
+ .open = blk_msg_open,
+ .write = blk_msg_write,
+};
+
/*
* Keep track of how many times we encountered a full subbuffer, to aid
* the user space app in telling how many lost events there were.
/*
* Setup everything required to start tracing
*/
-static int blk_trace_setup(request_queue_t *q, struct block_device *bdev,
- char __user *arg)
+int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
+ struct blk_user_trace_setup *buts)
{
- struct blk_user_trace_setup buts;
struct blk_trace *old_bt, *bt = NULL;
struct dentry *dir = NULL;
- char b[BDEVNAME_SIZE];
int ret, i;
- if (copy_from_user(&buts, arg, sizeof(buts)))
- return -EFAULT;
-
- if (!buts.buf_size || !buts.buf_nr)
+ if (!buts->buf_size || !buts->buf_nr)
return -EINVAL;
- strcpy(buts.name, bdevname(bdev, b));
+ strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
+ buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
/*
* some device names have larger paths - convert the slashes
* to underscores for this to work as expected
*/
- for (i = 0; i < strlen(buts.name); i++)
- if (buts.name[i] == '/')
- buts.name[i] = '_';
-
- if (copy_to_user(arg, &buts, sizeof(buts)))
- return -EFAULT;
+ for (i = 0; i < strlen(buts->name); i++)
+ if (buts->name[i] == '/')
+ buts->name[i] = '_';
ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt->sequence)
goto err;
+ bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG);
+ if (!bt->msg_data)
+ goto err;
+
ret = -ENOENT;
- dir = blk_create_tree(buts.name);
+ dir = blk_create_tree(buts->name);
if (!dir)
goto err;
bt->dir = dir;
- bt->dev = bdev->bd_dev;
+ bt->dev = dev;
atomic_set(&bt->dropped, 0);
ret = -EIO;
if (!bt->dropped_file)
goto err;
- bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks, bt);
+ bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
+ if (!bt->msg_file)
+ goto err;
+
+ bt->rchan = relay_open("trace", dir, buts->buf_size,
+ buts->buf_nr, &blk_relay_callbacks, bt);
if (!bt->rchan)
goto err;
- bt->act_mask = buts.act_mask;
+ bt->act_mask = buts->act_mask;
if (!bt->act_mask)
bt->act_mask = (u16) -1;
- bt->start_lba = buts.start_lba;
- bt->end_lba = buts.end_lba;
+ bt->start_lba = buts->start_lba;
+ bt->end_lba = buts->end_lba;
if (!bt->end_lba)
bt->end_lba = -1ULL;
- bt->pid = buts.pid;
+ bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;
ret = -EBUSY;
if (dir)
blk_remove_tree(dir);
if (bt) {
+ if (bt->msg_file)
+ debugfs_remove(bt->msg_file);
if (bt->dropped_file)
debugfs_remove(bt->dropped_file);
free_percpu(bt->sequence);
+ free_percpu(bt->msg_data);
if (bt->rchan)
relay_close(bt->rchan);
kfree(bt);
return ret;
}
-static int blk_trace_startstop(request_queue_t *q, int start)
+int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
+ 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, &buts);
+ if (ret)
+ return ret;
+
+ if (copy_to_user(arg, &buts, sizeof(buts)))
+ return -EFAULT;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blk_trace_setup);
+
+int blk_trace_startstop(struct request_queue *q, int start)
{
struct blk_trace *bt;
int ret;
return ret;
}
+EXPORT_SYMBOL_GPL(blk_trace_startstop);
/**
* blk_trace_ioctl: - handle the ioctls associated with tracing
**/
int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
{
- request_queue_t *q;
+ struct request_queue *q;
int ret, start = 0;
+ char b[BDEVNAME_SIZE];
q = bdev_get_queue(bdev);
if (!q)
switch (cmd) {
case BLKTRACESETUP:
- ret = blk_trace_setup(q, bdev, arg);
+ bdevname(bdev, b);
+ ret = blk_trace_setup(q, b, bdev->bd_dev, arg);
break;
case BLKTRACESTART:
start = 1;
* @q: the request queue associated with the device
*
**/
-void blk_trace_shutdown(request_queue_t *q)
+void blk_trace_shutdown(struct request_queue *q)
{
if (q->blk_trace) {
blk_trace_startstop(q, 0);
blk_trace_remove(q);
}
}
-
-/*
- * Average offset over two calls to sched_clock() with a gettimeofday()
- * in the middle
- */
-static void blk_check_time(unsigned long long *t)
-{
- unsigned long long a, b;
- struct timeval tv;
-
- a = sched_clock();
- do_gettimeofday(&tv);
- b = sched_clock();
-
- *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
- *t -= (a + b) / 2;
-}
-
-/*
- * calibrate our inter-CPU timings
- */
-static void blk_trace_check_cpu_time(void *data)
-{
- unsigned long long *t;
- int cpu = get_cpu();
-
- t = &per_cpu(blk_trace_cpu_offset, cpu);
-
- /*
- * Just call it twice, hopefully the second call will be cache hot
- * and a little more precise
- */
- blk_check_time(t);
- blk_check_time(t);
-
- put_cpu();
-}
-
-static void blk_trace_set_ht_offsets(void)
-{
-#if defined(CONFIG_SCHED_SMT)
- int cpu, i;
-
- /*
- * now make sure HT siblings have the same time offset
- */
- preempt_disable();
- for_each_online_cpu(cpu) {
- unsigned long long *cpu_off, *sibling_off;
-
- for_each_cpu_mask(i, cpu_sibling_map[cpu]) {
- if (i == cpu)
- continue;
-
- cpu_off = &per_cpu(blk_trace_cpu_offset, cpu);
- sibling_off = &per_cpu(blk_trace_cpu_offset, i);
- *sibling_off = *cpu_off;
- }
- }
- preempt_enable();
-#endif
-}
-
-static __init int blk_trace_init(void)
-{
- mutex_init(&blk_tree_mutex);
- on_each_cpu(blk_trace_check_cpu_time, NULL, 1, 1);
- blk_trace_set_ht_offsets();
-
- return 0;
-}
-
-module_init(blk_trace_init);
-
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff