-F Format specification. The individual specifiers are:
+ A - Remap
B - Back merge
C - Complete
D - Issue
case __BLK_TA_BOUNCE:
log_generic(pci, t, "B");
break;
+ case __BLK_TA_REMAP:
+ log_generic(pci, t, "A");
+ break;
default:
fprintf(stderr, "Bad fs action %x\n", t->action);
break;
#include "blktrace.h"
-#define VALID_SPECS "BCDFGMPQRSTU"
+#define VALID_SPECS "ABCDFGMPQRSTUWX"
#define HEADER "%D %2c %8s %5T.%9t %5p %2a %3d "
return p;
}
+#define pdu_start(t) (((void *) (t) + sizeof(struct blk_io_trace)))
+
static unsigned int get_pdu_int(struct blk_io_trace *t)
{
- __u64 *val = (__u64 *) ((char *) t + sizeof(*t));
+ __u64 *val = pdu_start(t);
return be64_to_cpu(*val);
}
+static void get_pdu_remap(struct blk_io_trace *t, struct blk_io_trace_remap *r)
+{
+ struct blk_io_trace_remap *__r = pdu_start(t);
+
+ r->device = be32_to_cpu(__r->device);
+ r->sector = be64_to_cpu(__r->sector);
+}
+
static void print_field(char *act, struct per_cpu_info *pci,
struct blk_io_trace *t, unsigned long long elapsed,
int pdu_len, unsigned char *pdu_buf, char field,
break;
case 'U': /* Unplug IO */
- case 'T': { /* Unplug timer */
+ case 'T': /* Unplug timer */
fprintf(ofp, "[%s] %u\n", t->comm, get_pdu_int(t));
break;
- }
+ case 'A': { /* remap */
+ struct blk_io_trace_remap r;
+
+ get_pdu_remap(t, &r);
+ fprintf(ofp, "%llu + %u <- (%d,%d) %llu\n",
+ (unsigned long long) r.sector, t->bytes >> 10,
+ MAJOR(r.device), MINOR(r.device),
+ (unsigned long long) t->sector);
+ break;
+ }
+
case 'X': /* Split */
fprintf(ofp, "%llu / %u [%s]\n", (unsigned long long) t->sector,
get_pdu_int(t), t->comm);
__BLK_TA_INSERT, /* insert request */
__BLK_TA_SPLIT, /* bio was split */
__BLK_TA_BOUNCE, /* bio was bounced */
+ __BLK_TA_REMAP, /* bio was remapped */
};
/*
#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_SPLIT (__BLK_TA_SPLIT)
#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
+#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_IO_TRACE_MAGIC 0x65617400
#define BLK_IO_TRACE_VERSION 0x05
char comm[16]; /* task command name (TASK_COMM_LEN) */
};
+/*
+ * The remap event
+ */
+struct blk_io_trace_remap {
+ __u32 device;
+ __u64 sector;
+};
+
/*
* User setup structure passed with BLKSTARTTRACE
*/
normal boundary conditions. dm is notably bad at this and will clone
lots of io.
+ \item[A -- remap] For stacked devices, incoming io is remapped to device
+ below it in the io stack. The remap action details what exactly is
+ being remapped to what.
+
\end{description}
\subsection{\label{sec:blkparse-format}Output Description and Formatting}
\begin{tabular}{|l|l|}\hline
Act & Description \\ \hline\hline
+A & IO was remapped to a different device \\ \hline
B & IO back merged with request on queue \\ \hline
C & IO completion \\ \hline
D & IO issued to driver \\ \hline
sector (separated by a slash (/) is output, followed by the command
associated with the event (surrounded by square brackets).
+ \item[A -- remap] Sector and length is output, along with the original
+ device and sector offset.
+
\end{description}
%------------------------------
BLK\_TA\_INSERT & Insert request into queue. \\ \hline
BLK\_TA\_SPLIT & BIO split into 2 or more requests. \\ \hline
BLK\_TA\_BOUNCE & BIO was bounced \\ \hline
+ BLK\_TA\_REMAP & BIO was remapped \\ \hline
\end{tabular}
%..........................................
describes the nature of the payload, and is one of
BLK\_TA\_UNPLUG\_IO or BLK\_TA\_UNPLUG\_TIMER.
+ \item[blk\_add\_trace\_remap(struct request\_queue *q, struct bio *bio,
+ dev\_t dev, sector\_t sector)]
+ Adds a trace with a remap event. \emph{dev} and \emph{sector} denote
+ the original device this \emph{bio} was mapped from.
+
+
\end{description}
\end{document}
+++ /dev/null
-diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
---- a/drivers/block/Kconfig
-+++ b/drivers/block/Kconfig
-@@ -419,6 +419,14 @@ config LBD
- your machine, or if you want to have a raid or loopback device
- bigger than 2TB. Otherwise say N.
-
-+config BLK_DEV_IO_TRACE
-+ bool "Support for tracing block io actions"
-+ select RELAYFS_FS
-+ help
-+ Say Y here, if you want to be able to trace the block layer actions
-+ on a given queue.
-+
-+
- config CDROM_PKTCDVD
- tristate "Packet writing on CD/DVD media"
- depends on !UML
-diff --git a/drivers/block/Makefile b/drivers/block/Makefile
---- a/drivers/block/Makefile
-+++ b/drivers/block/Makefile
-@@ -45,3 +45,5 @@ obj-$(CONFIG_VIODASD) += viodasd.o
- obj-$(CONFIG_BLK_DEV_SX8) += sx8.o
- obj-$(CONFIG_BLK_DEV_UB) += ub.o
-
-+obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
-+
-diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
---- a/drivers/block/elevator.c
-+++ b/drivers/block/elevator.c
-@@ -34,6 +34,7 @@
- #include <linux/slab.h>
- #include <linux/init.h>
- #include <linux/compiler.h>
-+#include <linux/blktrace.h>
-
- #include <asm/uaccess.h>
-
-@@ -305,6 +306,8 @@ void elv_requeue_request(request_queue_t
- void __elv_add_request(request_queue_t *q, struct request *rq, int where,
- int plug)
- {
-+ blk_add_trace_rq(q, rq, BLK_TA_INSERT);
-+
- /*
- * barriers implicitly indicate back insertion
- */
-@@ -371,6 +374,9 @@ struct request *elv_next_request(request
- int ret;
-
- while ((rq = __elv_next_request(q)) != NULL) {
-+
-+ blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
-+
- /*
- * just mark as started even if we don't start it, a request
- * that has been delayed should not be passed by new incoming
-diff --git a/drivers/block/ioctl.c b/drivers/block/ioctl.c
---- a/drivers/block/ioctl.c
-+++ b/drivers/block/ioctl.c
-@@ -4,6 +4,7 @@
- #include <linux/backing-dev.h>
- #include <linux/buffer_head.h>
- #include <linux/smp_lock.h>
-+#include <linux/blktrace.h>
- #include <asm/uaccess.h>
-
- static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
-@@ -188,6 +189,10 @@ static int blkdev_locked_ioctl(struct fi
- return put_ulong(arg, bdev->bd_inode->i_size >> 9);
- case BLKGETSIZE64:
- return put_u64(arg, bdev->bd_inode->i_size);
-+ case BLKSTARTTRACE:
-+ return blk_start_trace(bdev, (char __user *) arg);
-+ case BLKSTOPTRACE:
-+ return blk_stop_trace(bdev);
- }
- return -ENOIOCTLCMD;
- }
-diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
---- a/drivers/block/ll_rw_blk.c
-+++ b/drivers/block/ll_rw_blk.c
-@@ -29,6 +29,7 @@
- #include <linux/swap.h>
- #include <linux/writeback.h>
- #include <linux/blkdev.h>
-+#include <linux/blktrace.h>
-
- /*
- * for max sense size
-@@ -1422,8 +1423,10 @@ void blk_plug_device(request_queue_t *q)
- if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags))
- return;
-
-- if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
-+ if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
- mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
-+ blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
-+ }
- }
-
- EXPORT_SYMBOL(blk_plug_device);
-@@ -1487,14 +1490,21 @@ static void blk_backing_dev_unplug(struc
- /*
- * devices don't necessarily have an ->unplug_fn defined
- */
-- if (q->unplug_fn)
-+ if (q->unplug_fn) {
-+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
-+ q->rq.count[READ] + q->rq.count[WRITE]);
-+
- q->unplug_fn(q);
-+ }
- }
-
- static void blk_unplug_work(void *data)
- {
- request_queue_t *q = data;
-
-+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
-+ q->rq.count[READ] + q->rq.count[WRITE]);
-+
- q->unplug_fn(q);
- }
-
-@@ -1502,6 +1512,9 @@ static void blk_unplug_timeout(unsigned
- {
- request_queue_t *q = (request_queue_t *)data;
-
-+ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL,
-+ q->rq.count[READ] + q->rq.count[WRITE]);
-+
- kblockd_schedule_work(&q->unplug_work);
- }
-
-@@ -1624,6 +1637,11 @@ void blk_cleanup_queue(request_queue_t *
- if (q->queue_tags)
- __blk_queue_free_tags(q);
-
-+ if (q->blk_trace) {
-+ blk_cleanup_trace(q->blk_trace);
-+ q->blk_trace = NULL;
-+ }
-+
- blk_queue_ordered(q, QUEUE_ORDERED_NONE);
-
- kmem_cache_free(requestq_cachep, q);
-@@ -1970,6 +1988,8 @@ rq_starved:
-
- rq_init(q, rq);
- rq->rl = rl;
-+
-+ blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
- out:
- return rq;
- }
-@@ -1998,6 +2018,8 @@ static struct request *get_request_wait(
- if (!rq) {
- struct io_context *ioc;
-
-+ blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ);
-+
- __generic_unplug_device(q);
- spin_unlock_irq(q->queue_lock);
- io_schedule();
-@@ -2051,6 +2073,8 @@ EXPORT_SYMBOL(blk_get_request);
- */
- void blk_requeue_request(request_queue_t *q, struct request *rq)
- {
-+ blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
-+
- if (blk_rq_tagged(rq))
- blk_queue_end_tag(q, rq);
-
-@@ -2676,6 +2700,8 @@ static int __make_request(request_queue_
- if (!q->back_merge_fn(q, req, bio))
- break;
-
-+ blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
-+
- req->biotail->bi_next = bio;
- req->biotail = bio;
- req->nr_sectors = req->hard_nr_sectors += nr_sectors;
-@@ -2691,6 +2717,8 @@ static int __make_request(request_queue_
- if (!q->front_merge_fn(q, req, bio))
- break;
-
-+ blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
-+
- bio->bi_next = req->bio;
- req->bio = bio;
-
-@@ -2991,6 +3019,8 @@ end_io:
- */
- blk_partition_remap(bio);
-
-+ blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
-+
- ret = q->make_request_fn(q, bio);
- } while (ret);
- }
-@@ -3110,6 +3140,8 @@ static int __end_that_request_first(stru
- int total_bytes, bio_nbytes, error, next_idx = 0;
- struct bio *bio;
-
-+ blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
-+
- /*
- * extend uptodate bool to allow < 0 value to be direct io error
- */
-diff --git a/fs/bio.c b/fs/bio.c
---- a/fs/bio.c
-+++ b/fs/bio.c
-@@ -25,6 +25,7 @@
- #include <linux/module.h>
- #include <linux/mempool.h>
- #include <linux/workqueue.h>
-+#include <linux/blktrace.h>
- #include <scsi/sg.h> /* for struct sg_iovec */
-
- #define BIO_POOL_SIZE 256
-@@ -1050,6 +1051,9 @@ struct bio_pair *bio_split(struct bio *b
- if (!bp)
- return bp;
-
-+ blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi,
-+ bi->bi_sector + first_sectors);
-+
- BUG_ON(bi->bi_vcnt != 1);
- BUG_ON(bi->bi_idx != 0);
- atomic_set(&bp->cnt, 3);
-diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
---- a/include/linux/blkdev.h
-+++ b/include/linux/blkdev.h
-@@ -22,6 +22,7 @@ typedef struct request_queue request_que
- struct elevator_queue;
- typedef struct elevator_queue elevator_t;
- struct request_pm_state;
-+struct blk_trace;
-
- #define BLKDEV_MIN_RQ 4
- #define BLKDEV_MAX_RQ 128 /* Default maximum */
-@@ -412,6 +413,8 @@ struct request_queue
- */
- struct request *flush_rq;
- unsigned char ordered;
-+
-+ struct blk_trace *blk_trace;
- };
-
- enum {
-diff --git a/include/linux/fs.h b/include/linux/fs.h
---- a/include/linux/fs.h
-+++ b/include/linux/fs.h
-@@ -196,6 +196,8 @@ extern int dir_notify_enable;
- #define BLKBSZGET _IOR(0x12,112,size_t)
- #define BLKBSZSET _IOW(0x12,113,size_t)
- #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
-+#define BLKSTARTTRACE _IOWR(0x12,115,struct blk_user_trace_setup)
-+#define BLKSTOPTRACE _IO(0x12,116)
-
- #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
- #define FIBMAP _IO(0x00,1) /* bmap access */
-diff --git a/mm/highmem.c b/mm/highmem.c
---- a/mm/highmem.c
-+++ b/mm/highmem.c
-@@ -26,6 +26,7 @@
- #include <linux/init.h>
- #include <linux/hash.h>
- #include <linux/highmem.h>
-+#include <linux/blktrace.h>
- #include <asm/tlbflush.h>
-
- static mempool_t *page_pool, *isa_page_pool;
-@@ -479,6 +480,8 @@ void blk_queue_bounce(request_queue_t *q
- pool = isa_page_pool;
- }
-
-+ blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
-+
- /*
- * slow path
- */
---- /dev/null 2005-09-09 21:24:12.000000000 +0200
-+++ linux-2.6/drivers/block/blktrace.c 2005-09-28 08:46:33.000000000 +0200
-@@ -0,0 +1,232 @@
-+#include <linux/config.h>
-+#include <linux/kernel.h>
-+#include <linux/blkdev.h>
-+#include <linux/blktrace.h>
-+#include <linux/percpu.h>
-+#include <linux/init.h>
-+#include <asm/uaccess.h>
-+
-+static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, };
-+
-+void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
-+ int rw, u32 what, int error, int pdu_len, void *pdu_data)
-+{
-+ struct blk_io_trace t;
-+ unsigned long flags;
-+ int cpu;
-+
-+ if (rw & (1 << BIO_RW_BARRIER))
-+ what |= BLK_TC_ACT(BLK_TC_BARRIER);
-+ if (rw & (1 << BIO_RW_SYNC))
-+ what |= BLK_TC_ACT(BLK_TC_SYNC);
-+
-+ if (rw & WRITE)
-+ what |= BLK_TC_ACT(BLK_TC_WRITE);
-+ else
-+ what |= BLK_TC_ACT(BLK_TC_READ);
-+
-+ if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
-+ return;
-+
-+ t.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
-+
-+ t.device = bt->dev;
-+ t.sector = sector;
-+ t.bytes = bytes;
-+ t.action = what;
-+ t.error = error;
-+ t.pdu_len = pdu_len;
-+
-+ t.pid = current->pid;
-+ memcpy(t.comm, current->comm, sizeof(t.comm));
-+
-+ /*
-+ * need to serialize this part on the local processor to prevent
-+ * interrupts for messing with sequence <-> time relation
-+ */
-+ local_irq_save(flags);
-+
-+ t.sequence = atomic_add_return(1, &bt->sequence);
-+
-+ cpu = smp_processor_id();
-+ t.cpu = cpu;
-+ t.time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu);
-+
-+ __relay_write(bt->rchan, &t, sizeof(t));
-+ if (pdu_len)
-+ __relay_write(bt->rchan, pdu_data, pdu_len);
-+
-+ local_irq_restore(flags);
-+}
-+
-+EXPORT_SYMBOL_GPL(__blk_add_trace);
-+
-+static struct dentry *blk_tree_root;
-+static DECLARE_MUTEX(blk_tree_mutex);
-+
-+static inline void blk_remove_root(void)
-+{
-+ if (relayfs_remove_dir(blk_tree_root) != -ENOTEMPTY)
-+ blk_tree_root = NULL;
-+}
-+
-+static void blk_remove_tree(struct dentry *dir)
-+{
-+ down(&blk_tree_mutex);
-+ relayfs_remove_dir(dir);
-+ blk_remove_root();
-+ up(&blk_tree_mutex);
-+}
-+
-+static struct dentry *blk_create_tree(const char *blk_name)
-+{
-+ struct dentry *dir = NULL;
-+
-+ down(&blk_tree_mutex);
-+
-+ if (!blk_tree_root) {
-+ blk_tree_root = relayfs_create_dir("block", NULL);
-+ if (!blk_tree_root)
-+ goto err;
-+ }
-+
-+ dir = relayfs_create_dir(blk_name, blk_tree_root);
-+ if (!dir)
-+ blk_remove_root();
-+
-+err:
-+ up(&blk_tree_mutex);
-+ return dir;
-+}
-+
-+void blk_cleanup_trace(struct blk_trace *bt)
-+{
-+ relay_close(bt->rchan);
-+ blk_remove_tree(bt->dir);
-+ kfree(bt);
-+}
-+
-+int blk_stop_trace(struct block_device *bdev)
-+{
-+ request_queue_t *q = bdev_get_queue(bdev);
-+ struct blk_trace *bt = NULL;
-+ int ret = -EINVAL;
-+
-+ if (!q)
-+ return -ENXIO;
-+
-+ down(&bdev->bd_sem);
-+
-+ if (q->blk_trace) {
-+ bt = q->blk_trace;
-+ q->blk_trace = NULL;
-+ ret = 0;
-+ }
-+
-+ up(&bdev->bd_sem);
-+
-+ if (bt)
-+ blk_cleanup_trace(bt);
-+
-+ return ret;
-+}
-+
-+int blk_start_trace(struct block_device *bdev, char __user *arg)
-+{
-+ request_queue_t *q = bdev_get_queue(bdev);
-+ struct blk_user_trace_setup buts;
-+ struct blk_trace *bt = NULL;
-+ struct dentry *dir = NULL;
-+ char b[BDEVNAME_SIZE];
-+ int ret;
-+
-+ if (!q)
-+ return -ENXIO;
-+
-+ if (copy_from_user(&buts, arg, sizeof(buts)))
-+ return -EFAULT;
-+
-+ if (!buts.buf_size || !buts.buf_nr)
-+ return -EINVAL;
-+
-+ strcpy(buts.name, bdevname(bdev, b));
-+
-+ if (copy_to_user(arg, &buts, sizeof(buts)))
-+ return -EFAULT;
-+
-+ down(&bdev->bd_sem);
-+ ret = -EBUSY;
-+ if (q->blk_trace)
-+ goto err;
-+
-+ ret = -ENOMEM;
-+ bt = kmalloc(sizeof(*bt), GFP_KERNEL);
-+ if (!bt)
-+ goto err;
-+
-+ ret = -ENOENT;
-+ dir = blk_create_tree(bdevname(bdev, b));
-+ if (!dir)
-+ goto err;
-+
-+ bt->dir = dir;
-+ bt->dev = bdev->bd_dev;
-+ atomic_set(&bt->sequence, 0);
-+
-+ ret = -EIO;
-+ bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, NULL);
-+ if (!bt->rchan)
-+ goto err;
-+
-+ bt->act_mask = buts.act_mask;
-+ if (!bt->act_mask)
-+ bt->act_mask = (u16) -1;
-+
-+ q->blk_trace = bt;
-+ up(&bdev->bd_sem);
-+ return 0;
-+err:
-+ up(&bdev->bd_sem);
-+ if (dir)
-+ blk_remove_tree(dir);
-+ if (bt)
-+ kfree(bt);
-+ return ret;
-+}
-+
-+static void blk_trace_check_cpu_time(void *data)
-+{
-+ unsigned long long a, b, *t;
-+ struct timeval tv;
-+ int cpu = get_cpu();
-+
-+ t = &per_cpu(blk_trace_cpu_offset, cpu);
-+
-+ a = sched_clock();
-+ do_gettimeofday(&tv);
-+ b = sched_clock();
-+
-+ *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
-+ *t -= (a + b) / 2;
-+ put_cpu();
-+}
-+
-+static int blk_trace_calibrate_offsets(void)
-+{
-+ unsigned long flags;
-+
-+ smp_call_function(blk_trace_check_cpu_time, NULL, 1, 1);
-+ local_irq_save(flags);
-+ blk_trace_check_cpu_time(NULL);
-+ local_irq_restore(flags);
-+
-+ return 0;
-+}
-+
-+static __init int blk_trace_init(void)
-+{
-+ return blk_trace_calibrate_offsets();
-+}
-+
-+module_init(blk_trace_init);
-+
---- /dev/null 2005-09-09 21:24:12.000000000 +0200
-+++ linux-2.6/include/linux/blktrace.h 2005-09-28 08:46:33.000000000 +0200
-@@ -0,0 +1,180 @@
-+#ifndef BLKTRACE_H
-+#define BLKTRACE_H
-+
-+#include <linux/config.h>
-+#include <linux/blkdev.h>
-+#include <linux/relayfs_fs.h>
-+
-+/*
-+ * Trace categories
-+ */
-+enum {
-+ BLK_TC_READ = 1 << 0, /* reads */
-+ BLK_TC_WRITE = 1 << 1, /* writes */
-+ BLK_TC_BARRIER = 1 << 2, /* barrier */
-+ BLK_TC_SYNC = 1 << 3, /* barrier */
-+ BLK_TC_QUEUE = 1 << 4, /* queueing/merging */
-+ BLK_TC_REQUEUE = 1 << 5, /* requeueing */
-+ BLK_TC_ISSUE = 1 << 6, /* issue */
-+ BLK_TC_COMPLETE = 1 << 7, /* completions */
-+ BLK_TC_FS = 1 << 8, /* fs requests */
-+ BLK_TC_PC = 1 << 9, /* pc requests */
-+
-+ BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
-+};
-+
-+#define BLK_TC_SHIFT (16)
-+#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT)
-+
-+/*
-+ * Basic trace actions
-+ */
-+enum {
-+ __BLK_TA_QUEUE = 1, /* queued */
-+ __BLK_TA_BACKMERGE, /* back merged to existing rq */
-+ __BLK_TA_FRONTMERGE, /* front merge to existing rq */
-+ __BLK_TA_GETRQ, /* allocated new request */
-+ __BLK_TA_SLEEPRQ, /* sleeping on rq allocation */
-+ __BLK_TA_REQUEUE, /* request requeued */
-+ __BLK_TA_ISSUE, /* sent to driver */
-+ __BLK_TA_COMPLETE, /* completed by driver */
-+ __BLK_TA_PLUG, /* queue was plugged */
-+ __BLK_TA_UNPLUG_IO, /* queue was unplugged by io */
-+ __BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */
-+ __BLK_TA_INSERT, /* insert request */
-+ __BLK_TA_SPLIT, /* bio was split */
-+ __BLK_TA_BOUNCE, /* bio was bounced */
-+};
-+
-+/*
-+ * Trace actions in full. Additionally, read or write is masked
-+ */
-+#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
-+#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
-+#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
-+#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
-+#define BLK_TA_SPLIT (__BLK_TA_SPLIT)
-+#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
-+
-+#define BLK_IO_TRACE_MAGIC 0x65617400
-+#define BLK_IO_TRACE_VERSION 0x05
-+
-+/*
-+ * The trace itself
-+ */
-+struct blk_io_trace {
-+ u32 magic; /* MAGIC << 8 | version */
-+ u32 sequence; /* event number */
-+ u64 time; /* in microseconds */
-+ u64 sector; /* disk offset */
-+ u32 bytes; /* transfer length */
-+ u32 action; /* what happened */
-+ u32 pid; /* who did it */
-+ u32 cpu; /* on what cpu did it happen */
-+ u16 error; /* completion error */
-+ u16 pdu_len; /* length of data after this trace */
-+ u32 device; /* device number */
-+ char comm[16]; /* task command name (TASK_COMM_LEN) */
-+};
-+
-+struct blk_trace {
-+ struct dentry *dir;
-+ struct rchan *rchan;
-+ atomic_t sequence;
-+ u32 dev;
-+ u16 act_mask;
-+};
-+
-+/*
-+ * User setup structure passed with BLKSTARTTRACE
-+ */
-+struct blk_user_trace_setup {
-+ char name[BDEVNAME_SIZE]; /* output */
-+ u16 act_mask; /* input */
-+ u32 buf_size; /* input */
-+ u32 buf_nr; /* input */
-+};
-+
-+#if defined(CONFIG_BLK_DEV_IO_TRACE)
-+extern int blk_start_trace(struct block_device *, char __user *);
-+extern int blk_stop_trace(struct block_device *);
-+extern void blk_cleanup_trace(struct blk_trace *);
-+extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
-+
-+static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
-+ u32 what)
-+{
-+ struct blk_trace *bt = q->blk_trace;
-+ int rw = rq->flags & 0x07;
-+
-+ if (likely(!bt))
-+ return;
-+
-+ if (blk_pc_request(rq)) {
-+ what |= BLK_TC_ACT(BLK_TC_PC);
-+ __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
-+ } else {
-+ what |= BLK_TC_ACT(BLK_TC_FS);
-+ __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
-+ }
-+}
-+
-+static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
-+ u32 what)
-+{
-+ struct blk_trace *bt = q->blk_trace;
-+
-+ if (likely(!bt))
-+ return;
-+
-+ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
-+}
-+
-+static inline void blk_add_trace_generic(struct request_queue *q,
-+ struct bio *bio, int rw, u32 what)
-+{
-+ struct blk_trace *bt = q->blk_trace;
-+
-+ if (likely(!bt))
-+ return;
-+
-+ if (bio)
-+ blk_add_trace_bio(q, bio, what);
-+ else
-+ __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
-+}
-+
-+static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
-+ struct bio *bio, unsigned int pdu)
-+{
-+ struct blk_trace *bt = q->blk_trace;
-+ u64 rpdu = cpu_to_be64(pdu);
-+
-+ if (likely(!bt))
-+ return;
-+
-+ if (bio)
-+ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
-+ else
-+ __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
-+}
-+
-+#else /* !CONFIG_BLK_DEV_IO_TRACE */
-+#define blk_start_trace(bdev, arg) (-EINVAL)
-+#define blk_stop_trace(bdev) (-EINVAL)
-+#define blk_cleanup_trace(bt) do { } while (0)
-+#define blk_add_trace_rq(q, rq, what) do { } while (0)
-+#define blk_add_trace_bio(q, rq, what) do { } while (0)
-+#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
-+#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0)
-+#endif /* CONFIG_BLK_DEV_IO_TRACE */
-+
-+#endif
--- /dev/null
+diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
+--- a/drivers/block/Kconfig
++++ b/drivers/block/Kconfig
+@@ -419,6 +419,14 @@ config LBD
+ your machine, or if you want to have a raid or loopback device
+ bigger than 2TB. Otherwise say N.
+
++config BLK_DEV_IO_TRACE
++ bool "Support for tracing block io actions"
++ select RELAYFS_FS
++ help
++ Say Y here, if you want to be able to trace the block layer actions
++ on a given queue.
++
++
+ config CDROM_PKTCDVD
+ tristate "Packet writing on CD/DVD media"
+ depends on !UML
+diff --git a/drivers/block/Makefile b/drivers/block/Makefile
+--- a/drivers/block/Makefile
++++ b/drivers/block/Makefile
+@@ -45,3 +45,5 @@ obj-$(CONFIG_VIODASD) += viodasd.o
+ obj-$(CONFIG_BLK_DEV_SX8) += sx8.o
+ obj-$(CONFIG_BLK_DEV_UB) += ub.o
+
++obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
++
+diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
+--- a/drivers/block/elevator.c
++++ b/drivers/block/elevator.c
+@@ -34,6 +34,7 @@
+ #include <linux/slab.h>
+ #include <linux/init.h>
+ #include <linux/compiler.h>
++#include <linux/blktrace.h>
+
+ #include <asm/uaccess.h>
+
+@@ -305,6 +306,8 @@ void elv_requeue_request(request_queue_t
+ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
+ int plug)
+ {
++ blk_add_trace_rq(q, rq, BLK_TA_INSERT);
++
+ /*
+ * barriers implicitly indicate back insertion
+ */
+@@ -371,6 +374,9 @@ struct request *elv_next_request(request
+ int ret;
+
+ while ((rq = __elv_next_request(q)) != NULL) {
++
++ blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
++
+ /*
+ * just mark as started even if we don't start it, a request
+ * that has been delayed should not be passed by new incoming
+diff --git a/drivers/block/ioctl.c b/drivers/block/ioctl.c
+--- a/drivers/block/ioctl.c
++++ b/drivers/block/ioctl.c
+@@ -4,6 +4,7 @@
+ #include <linux/backing-dev.h>
+ #include <linux/buffer_head.h>
+ #include <linux/smp_lock.h>
++#include <linux/blktrace.h>
+ #include <asm/uaccess.h>
+
+ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
+@@ -188,6 +189,10 @@ static int blkdev_locked_ioctl(struct fi
+ return put_ulong(arg, bdev->bd_inode->i_size >> 9);
+ case BLKGETSIZE64:
+ return put_u64(arg, bdev->bd_inode->i_size);
++ case BLKSTARTTRACE:
++ return blk_start_trace(bdev, (char __user *) arg);
++ case BLKSTOPTRACE:
++ return blk_stop_trace(bdev);
+ }
+ return -ENOIOCTLCMD;
+ }
+diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
+--- a/drivers/block/ll_rw_blk.c
++++ b/drivers/block/ll_rw_blk.c
+@@ -29,6 +29,7 @@
+ #include <linux/swap.h>
+ #include <linux/writeback.h>
+ #include <linux/blkdev.h>
++#include <linux/blktrace.h>
+
+ /*
+ * for max sense size
+@@ -1422,8 +1423,10 @@ void blk_plug_device(request_queue_t *q)
+ if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags))
+ return;
+
+- if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
++ if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
+ mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
++ blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
++ }
+ }
+
+ EXPORT_SYMBOL(blk_plug_device);
+@@ -1487,14 +1490,21 @@ static void blk_backing_dev_unplug(struc
+ /*
+ * devices don't necessarily have an ->unplug_fn defined
+ */
+- if (q->unplug_fn)
++ if (q->unplug_fn) {
++ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
++ q->rq.count[READ] + q->rq.count[WRITE]);
++
+ q->unplug_fn(q);
++ }
+ }
+
+ static void blk_unplug_work(void *data)
+ {
+ request_queue_t *q = data;
+
++ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
++ q->rq.count[READ] + q->rq.count[WRITE]);
++
+ q->unplug_fn(q);
+ }
+
+@@ -1502,6 +1512,9 @@ static void blk_unplug_timeout(unsigned
+ {
+ request_queue_t *q = (request_queue_t *)data;
+
++ blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL,
++ q->rq.count[READ] + q->rq.count[WRITE]);
++
+ kblockd_schedule_work(&q->unplug_work);
+ }
+
+@@ -1624,6 +1637,11 @@ void blk_cleanup_queue(request_queue_t *
+ if (q->queue_tags)
+ __blk_queue_free_tags(q);
+
++ if (q->blk_trace) {
++ blk_cleanup_trace(q->blk_trace);
++ q->blk_trace = NULL;
++ }
++
+ blk_queue_ordered(q, QUEUE_ORDERED_NONE);
+
+ kmem_cache_free(requestq_cachep, q);
+@@ -1970,6 +1988,8 @@ rq_starved:
+
+ rq_init(q, rq);
+ rq->rl = rl;
++
++ blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
+ out:
+ return rq;
+ }
+@@ -1998,6 +2018,8 @@ static struct request *get_request_wait(
+ if (!rq) {
+ struct io_context *ioc;
+
++ blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ);
++
+ __generic_unplug_device(q);
+ spin_unlock_irq(q->queue_lock);
+ io_schedule();
+@@ -2051,6 +2073,8 @@ EXPORT_SYMBOL(blk_get_request);
+ */
+ void blk_requeue_request(request_queue_t *q, struct request *rq)
+ {
++ blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
++
+ if (blk_rq_tagged(rq))
+ blk_queue_end_tag(q, rq);
+
+@@ -2676,6 +2700,8 @@ static int __make_request(request_queue_
+ if (!q->back_merge_fn(q, req, bio))
+ break;
+
++ blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
++
+ req->biotail->bi_next = bio;
+ req->biotail = bio;
+ req->nr_sectors = req->hard_nr_sectors += nr_sectors;
+@@ -2691,6 +2717,8 @@ static int __make_request(request_queue_
+ if (!q->front_merge_fn(q, req, bio))
+ break;
+
++ blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
++
+ bio->bi_next = req->bio;
+ req->bio = bio;
+
+@@ -2931,6 +2959,7 @@ void generic_make_request(struct bio *bi
+ request_queue_t *q;
+ sector_t maxsector;
+ int ret, nr_sectors = bio_sectors(bio);
++ dev_t old_dev;
+
+ might_sleep();
+ /* Test device or partition size, when known. */
+@@ -2957,6 +2986,8 @@ void generic_make_request(struct bio *bi
+ * NOTE: we don't repeat the blk_size check for each new device.
+ * Stacking drivers are expected to know what they are doing.
+ */
++ maxsector = -1;
++ old_dev = 0;
+ do {
+ char b[BDEVNAME_SIZE];
+
+@@ -2991,6 +3022,14 @@ end_io:
+ */
+ blk_partition_remap(bio);
+
++ if (maxsector != -1)
++ blk_add_trace_remap(q, bio, old_dev, maxsector);
++
++ blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
++
++ maxsector = bio->bi_sector;
++ old_dev = bio->bi_bdev->bd_dev;
++
+ ret = q->make_request_fn(q, bio);
+ } while (ret);
+ }
+@@ -3110,6 +3149,8 @@ static int __end_that_request_first(stru
+ int total_bytes, bio_nbytes, error, next_idx = 0;
+ struct bio *bio;
+
++ blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
++
+ /*
+ * extend uptodate bool to allow < 0 value to be direct io error
+ */
+diff --git a/fs/bio.c b/fs/bio.c
+--- a/fs/bio.c
++++ b/fs/bio.c
+@@ -25,6 +25,7 @@
+ #include <linux/module.h>
+ #include <linux/mempool.h>
+ #include <linux/workqueue.h>
++#include <linux/blktrace.h>
+ #include <scsi/sg.h> /* for struct sg_iovec */
+
+ #define BIO_POOL_SIZE 256
+@@ -1050,6 +1051,9 @@ struct bio_pair *bio_split(struct bio *b
+ if (!bp)
+ return bp;
+
++ blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi,
++ bi->bi_sector + first_sectors);
++
+ BUG_ON(bi->bi_vcnt != 1);
+ BUG_ON(bi->bi_idx != 0);
+ atomic_set(&bp->cnt, 3);
+diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
+--- a/include/linux/blkdev.h
++++ b/include/linux/blkdev.h
+@@ -22,6 +22,7 @@ typedef struct request_queue request_que
+ struct elevator_queue;
+ typedef struct elevator_queue elevator_t;
+ struct request_pm_state;
++struct blk_trace;
+
+ #define BLKDEV_MIN_RQ 4
+ #define BLKDEV_MAX_RQ 128 /* Default maximum */
+@@ -412,6 +413,8 @@ struct request_queue
+ */
+ struct request *flush_rq;
+ unsigned char ordered;
++
++ struct blk_trace *blk_trace;
+ };
+
+ enum {
+diff --git a/include/linux/fs.h b/include/linux/fs.h
+--- a/include/linux/fs.h
++++ b/include/linux/fs.h
+@@ -196,6 +196,8 @@ extern int dir_notify_enable;
+ #define BLKBSZGET _IOR(0x12,112,size_t)
+ #define BLKBSZSET _IOW(0x12,113,size_t)
+ #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
++#define BLKSTARTTRACE _IOWR(0x12,115,struct blk_user_trace_setup)
++#define BLKSTOPTRACE _IO(0x12,116)
+
+ #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
+ #define FIBMAP _IO(0x00,1) /* bmap access */
+diff --git a/mm/highmem.c b/mm/highmem.c
+--- a/mm/highmem.c
++++ b/mm/highmem.c
+@@ -26,6 +26,7 @@
+ #include <linux/init.h>
+ #include <linux/hash.h>
+ #include <linux/highmem.h>
++#include <linux/blktrace.h>
+ #include <asm/tlbflush.h>
+
+ static mempool_t *page_pool, *isa_page_pool;
+@@ -479,6 +480,8 @@ void blk_queue_bounce(request_queue_t *q
+ pool = isa_page_pool;
+ }
+
++ blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
++
+ /*
+ * slow path
+ */
+--- /dev/null 2005-09-09 21:24:12.000000000 +0200
++++ linux-2.6/drivers/block/blktrace.c 2005-09-28 08:46:33.000000000 +0200
+@@ -0,0 +1,232 @@
++#include <linux/config.h>
++#include <linux/kernel.h>
++#include <linux/blkdev.h>
++#include <linux/blktrace.h>
++#include <linux/percpu.h>
++#include <linux/init.h>
++#include <asm/uaccess.h>
++
++static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, };
++
++void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
++ int rw, u32 what, int error, int pdu_len, void *pdu_data)
++{
++ struct blk_io_trace t;
++ unsigned long flags;
++ int cpu;
++
++ if (rw & (1 << BIO_RW_BARRIER))
++ what |= BLK_TC_ACT(BLK_TC_BARRIER);
++ if (rw & (1 << BIO_RW_SYNC))
++ what |= BLK_TC_ACT(BLK_TC_SYNC);
++
++ if (rw & WRITE)
++ what |= BLK_TC_ACT(BLK_TC_WRITE);
++ else
++ what |= BLK_TC_ACT(BLK_TC_READ);
++
++ if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
++ return;
++
++ t.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
++
++ t.device = bt->dev;
++ t.sector = sector;
++ t.bytes = bytes;
++ t.action = what;
++ t.error = error;
++ t.pdu_len = pdu_len;
++
++ t.pid = current->pid;
++ memcpy(t.comm, current->comm, sizeof(t.comm));
++
++ /*
++ * need to serialize this part on the local processor to prevent
++ * interrupts for messing with sequence <-> time relation
++ */
++ local_irq_save(flags);
++
++ t.sequence = atomic_add_return(1, &bt->sequence);
++
++ cpu = smp_processor_id();
++ t.cpu = cpu;
++ t.time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu);
++
++ __relay_write(bt->rchan, &t, sizeof(t));
++ if (pdu_len)
++ __relay_write(bt->rchan, pdu_data, pdu_len);
++
++ local_irq_restore(flags);
++}
++
++EXPORT_SYMBOL_GPL(__blk_add_trace);
++
++static struct dentry *blk_tree_root;
++static DECLARE_MUTEX(blk_tree_mutex);
++
++static inline void blk_remove_root(void)
++{
++ if (relayfs_remove_dir(blk_tree_root) != -ENOTEMPTY)
++ blk_tree_root = NULL;
++}
++
++static void blk_remove_tree(struct dentry *dir)
++{
++ down(&blk_tree_mutex);
++ relayfs_remove_dir(dir);
++ blk_remove_root();
++ up(&blk_tree_mutex);
++}
++
++static struct dentry *blk_create_tree(const char *blk_name)
++{
++ struct dentry *dir = NULL;
++
++ down(&blk_tree_mutex);
++
++ if (!blk_tree_root) {
++ blk_tree_root = relayfs_create_dir("block", NULL);
++ if (!blk_tree_root)
++ goto err;
++ }
++
++ dir = relayfs_create_dir(blk_name, blk_tree_root);
++ if (!dir)
++ blk_remove_root();
++
++err:
++ up(&blk_tree_mutex);
++ return dir;
++}
++
++void blk_cleanup_trace(struct blk_trace *bt)
++{
++ relay_close(bt->rchan);
++ blk_remove_tree(bt->dir);
++ kfree(bt);
++}
++
++int blk_stop_trace(struct block_device *bdev)
++{
++ request_queue_t *q = bdev_get_queue(bdev);
++ struct blk_trace *bt = NULL;
++ int ret = -EINVAL;
++
++ if (!q)
++ return -ENXIO;
++
++ down(&bdev->bd_sem);
++
++ if (q->blk_trace) {
++ bt = q->blk_trace;
++ q->blk_trace = NULL;
++ ret = 0;
++ }
++
++ up(&bdev->bd_sem);
++
++ if (bt)
++ blk_cleanup_trace(bt);
++
++ return ret;
++}
++
++int blk_start_trace(struct block_device *bdev, char __user *arg)
++{
++ request_queue_t *q = bdev_get_queue(bdev);
++ struct blk_user_trace_setup buts;
++ struct blk_trace *bt = NULL;
++ struct dentry *dir = NULL;
++ char b[BDEVNAME_SIZE];
++ int ret;
++
++ if (!q)
++ return -ENXIO;
++
++ if (copy_from_user(&buts, arg, sizeof(buts)))
++ return -EFAULT;
++
++ if (!buts.buf_size || !buts.buf_nr)
++ return -EINVAL;
++
++ strcpy(buts.name, bdevname(bdev, b));
++
++ if (copy_to_user(arg, &buts, sizeof(buts)))
++ return -EFAULT;
++
++ down(&bdev->bd_sem);
++ ret = -EBUSY;
++ if (q->blk_trace)
++ goto err;
++
++ ret = -ENOMEM;
++ bt = kmalloc(sizeof(*bt), GFP_KERNEL);
++ if (!bt)
++ goto err;
++
++ ret = -ENOENT;
++ dir = blk_create_tree(bdevname(bdev, b));
++ if (!dir)
++ goto err;
++
++ bt->dir = dir;
++ bt->dev = bdev->bd_dev;
++ atomic_set(&bt->sequence, 0);
++
++ ret = -EIO;
++ bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, NULL);
++ if (!bt->rchan)
++ goto err;
++
++ bt->act_mask = buts.act_mask;
++ if (!bt->act_mask)
++ bt->act_mask = (u16) -1;
++
++ q->blk_trace = bt;
++ up(&bdev->bd_sem);
++ return 0;
++err:
++ up(&bdev->bd_sem);
++ if (dir)
++ blk_remove_tree(dir);
++ if (bt)
++ kfree(bt);
++ return ret;
++}
++
++static void blk_trace_check_cpu_time(void *data)
++{
++ unsigned long long a, b, *t;
++ struct timeval tv;
++ int cpu = get_cpu();
++
++ t = &per_cpu(blk_trace_cpu_offset, cpu);
++
++ a = sched_clock();
++ do_gettimeofday(&tv);
++ b = sched_clock();
++
++ *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
++ *t -= (a + b) / 2;
++ put_cpu();
++}
++
++static int blk_trace_calibrate_offsets(void)
++{
++ unsigned long flags;
++
++ smp_call_function(blk_trace_check_cpu_time, NULL, 1, 1);
++ local_irq_save(flags);
++ blk_trace_check_cpu_time(NULL);
++ local_irq_restore(flags);
++
++ return 0;
++}
++
++static __init int blk_trace_init(void)
++{
++ return blk_trace_calibrate_offsets();
++}
++
++module_init(blk_trace_init);
++
+--- /dev/null 2005-09-09 21:24:12.000000000 +0200
++++ linux-2.6/include/linux/blktrace.h 2005-10-06 09:38:46.000000000 +0200
+@@ -0,0 +1,206 @@
++#ifndef BLKTRACE_H
++#define BLKTRACE_H
++
++#include <linux/config.h>
++#include <linux/blkdev.h>
++#include <linux/relayfs_fs.h>
++
++/*
++ * Trace categories
++ */
++enum blktrace_cat {
++ BLK_TC_READ = 1 << 0, /* reads */
++ BLK_TC_WRITE = 1 << 1, /* writes */
++ BLK_TC_BARRIER = 1 << 2, /* barrier */
++ BLK_TC_SYNC = 1 << 3, /* barrier */
++ BLK_TC_QUEUE = 1 << 4, /* queueing/merging */
++ BLK_TC_REQUEUE = 1 << 5, /* requeueing */
++ BLK_TC_ISSUE = 1 << 6, /* issue */
++ BLK_TC_COMPLETE = 1 << 7, /* completions */
++ BLK_TC_FS = 1 << 8, /* fs requests */
++ BLK_TC_PC = 1 << 9, /* pc requests */
++
++ BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
++};
++
++#define BLK_TC_SHIFT (16)
++#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT)
++
++/*
++ * Basic trace actions
++ */
++enum blktrace_act {
++ __BLK_TA_QUEUE = 1, /* queued */
++ __BLK_TA_BACKMERGE, /* back merged to existing rq */
++ __BLK_TA_FRONTMERGE, /* front merge to existing rq */
++ __BLK_TA_GETRQ, /* allocated new request */
++ __BLK_TA_SLEEPRQ, /* sleeping on rq allocation */
++ __BLK_TA_REQUEUE, /* request requeued */
++ __BLK_TA_ISSUE, /* sent to driver */
++ __BLK_TA_COMPLETE, /* completed by driver */
++ __BLK_TA_PLUG, /* queue was plugged */
++ __BLK_TA_UNPLUG_IO, /* queue was unplugged by io */
++ __BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */
++ __BLK_TA_INSERT, /* insert request */
++ __BLK_TA_SPLIT, /* bio was split */
++ __BLK_TA_BOUNCE, /* bio was bounced */
++ __BLK_TA_REMAP, /* bio was remapped */
++};
++
++/*
++ * Trace actions in full. Additionally, read or write is masked
++ */
++#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
++#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
++#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
++#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
++#define BLK_TA_SPLIT (__BLK_TA_SPLIT)
++#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
++#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
++
++#define BLK_IO_TRACE_MAGIC 0x65617400
++#define BLK_IO_TRACE_VERSION 0x05
++
++/*
++ * The trace itself
++ */
++struct blk_io_trace {
++ u32 magic; /* MAGIC << 8 | version */
++ u32 sequence; /* event number */
++ u64 time; /* in microseconds */
++ u64 sector; /* disk offset */
++ u32 bytes; /* transfer length */
++ u32 action; /* what happened */
++ u32 pid; /* who did it */
++ u32 cpu; /* on what cpu did it happen */
++ u16 error; /* completion error */
++ u16 pdu_len; /* length of data after this trace */
++ u32 device; /* device number */
++ char comm[16]; /* task command name (TASK_COMM_LEN) */
++};
++
++/*
++ * The remap event
++ */
++struct blk_io_trace_remap {
++ u32 device;
++ u64 sector;
++};
++
++struct blk_trace {
++ struct dentry *dir;
++ struct rchan *rchan;
++ atomic_t sequence;
++ u32 dev;
++ u16 act_mask;
++};
++
++/*
++ * User setup structure passed with BLKSTARTTRACE
++ */
++struct blk_user_trace_setup {
++ char name[BDEVNAME_SIZE]; /* output */
++ u16 act_mask; /* input */
++ u32 buf_size; /* input */
++ u32 buf_nr; /* input */
++};
++
++#if defined(CONFIG_BLK_DEV_IO_TRACE)
++extern int blk_start_trace(struct block_device *, char __user *);
++extern int blk_stop_trace(struct block_device *);
++extern void blk_cleanup_trace(struct blk_trace *);
++extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
++
++static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
++ u32 what)
++{
++ struct blk_trace *bt = q->blk_trace;
++ int rw = rq->flags & 0x07;
++
++ if (likely(!bt))
++ return;
++
++ if (blk_pc_request(rq)) {
++ what |= BLK_TC_ACT(BLK_TC_PC);
++ __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
++ } else {
++ what |= BLK_TC_ACT(BLK_TC_FS);
++ __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
++ }
++}
++
++static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
++ u32 what)
++{
++ struct blk_trace *bt = q->blk_trace;
++
++ if (likely(!bt))
++ return;
++
++ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
++}
++
++static inline void blk_add_trace_generic(struct request_queue *q,
++ struct bio *bio, int rw, u32 what)
++{
++ struct blk_trace *bt = q->blk_trace;
++
++ if (likely(!bt))
++ return;
++
++ if (bio)
++ blk_add_trace_bio(q, bio, what);
++ else
++ __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
++}
++
++static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
++ struct bio *bio, unsigned int pdu)
++{
++ struct blk_trace *bt = q->blk_trace;
++ u64 rpdu = cpu_to_be64(pdu);
++
++ if (likely(!bt))
++ return;
++
++ if (bio)
++ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
++ else
++ __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
++}
++
++static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio, dev_t dev,
++ sector_t sector)
++{
++ struct blk_trace *bt = q->blk_trace;
++ struct blk_io_trace_remap r;
++
++ if (likely(!bt))
++ return;
++
++ r.device = cpu_to_be32(dev);
++ r.sector = cpu_to_be64(sector);
++
++ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
++}
++
++#else /* !CONFIG_BLK_DEV_IO_TRACE */
++#define blk_start_trace(bdev, arg) (-EINVAL)
++#define blk_stop_trace(bdev) (-EINVAL)
++#define blk_cleanup_trace(bt) do { } while (0)
++#define blk_add_trace_rq(q, rq, what) do { } while (0)
++#define blk_add_trace_bio(q, rq, what) do { } while (0)
++#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
++#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0)
++#define blk_add_trace_remap(q, bio, dev, sec) do {} while (0)
++#endif /* CONFIG_BLK_DEV_IO_TRACE */
++
++#endif
projects / blktrace.git / commitdiff