+++ /dev/null
-diff --git a/block/Kconfig b/block/Kconfig
-index 377f6dd..9678364 100644
---- a/block/Kconfig
-+++ b/block/Kconfig
-@@ -11,4 +11,16 @@ 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 RELAY
-+ select DEBUG_FS
-+ help
-+ Say Y here, if you want to be able to trace the block layer actions
-+ on a given queue. Tracing allows you to see any traffic happening
-+ on a block device queue. For more information (and the user space
-+ support tools needed), fetch the blktrace app from:
-+
-+ git://brick.kernel.dk/data/git/blktrace.git
-+
- source block/Kconfig.iosched
-diff --git a/block/Makefile b/block/Makefile
-index 7e4f93e..c05de0e 100644
---- a/block/Makefile
-+++ b/block/Makefile
-@@ -8,3 +8,5 @@ obj-$(CONFIG_IOSCHED_NOOP) += noop-iosch
- obj-$(CONFIG_IOSCHED_AS) += as-iosched.o
- obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o
- obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
-+
-+obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
-diff --git a/block/blktrace.c b/block/blktrace.c
-new file mode 100644
-index 0000000..c824644
---- /dev/null
-+++ b/block/blktrace.c
-@@ -0,0 +1,539 @@
-+/*
-+ * Copyright (C) 2006 Jens Axboe <axboe@suse.de>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-+ * GNU General Public License for more details.
-+ *
-+ * You should have received a copy of the GNU General Public License
-+ * along with this program; if not, write to the Free Software
-+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-+ *
-+ */
-+#include <linux/config.h>
-+#include <linux/kernel.h>
-+#include <linux/blkdev.h>
-+#include <linux/blktrace_api.h>
-+#include <linux/percpu.h>
-+#include <linux/init.h>
-+#include <linux/mutex.h>
-+#include <linux/debugfs.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;
-+
-+/*
-+ * Send out a notify for this process, if we haven't done so since a trace
-+ * started
-+ */
-+static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
-+{
-+ struct blk_io_trace *t;
-+
-+ t = relay_reserve(bt->rchan, sizeof(*t) + sizeof(tsk->comm));
-+ if (t) {
-+ t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
-+ t->device = bt->dev;
-+ t->action = BLK_TC_ACT(BLK_TC_NOTIFY);
-+ t->pid = tsk->pid;
-+ t->cpu = smp_processor_id();
-+ t->pdu_len = sizeof(tsk->comm);
-+ memcpy((void *) t + sizeof(*t), tsk->comm, t->pdu_len);
-+ tsk->btrace_seq = blktrace_seq;
-+ }
-+}
-+
-+static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
-+ pid_t pid)
-+{
-+ if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
-+ return 1;
-+ if (sector < bt->start_lba || sector > bt->end_lba)
-+ return 1;
-+ if (bt->pid && pid != bt->pid)
-+ return 1;
-+
-+ return 0;
-+}
-+
-+/*
-+ * Data direction bit lookup
-+ */
-+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[3] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC) };
-+
-+/*
-+ * 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))
-+
-+/*
-+ * The worker for the various blk_add_trace*() types. Fills out a
-+ * blk_io_trace structure and places it in a per-cpu subbuffer.
-+ */
-+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 task_struct *tsk = current;
-+ struct blk_io_trace *t;
-+ unsigned long flags;
-+ unsigned long *sequence;
-+ pid_t pid;
-+ int cpu;
-+
-+ if (unlikely(bt->trace_state != Blktrace_running))
-+ return;
-+
-+ what |= ddir_act[rw & WRITE];
-+ what |= bio_act[trace_barrier_bit(rw)];
-+ what |= bio_act[trace_sync_bit(rw)];
-+
-+ pid = tsk->pid;
-+ if (unlikely(act_log_check(bt, what, sector, pid)))
-+ return;
-+
-+ /*
-+ * 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
-+ */
-+ local_irq_save(flags);
-+
-+ if (unlikely(tsk->btrace_seq != blktrace_seq))
-+ trace_note_tsk(bt, tsk);
-+
-+ t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len);
-+ if (t) {
-+ cpu = smp_processor_id();
-+ sequence = per_cpu_ptr(bt->sequence, cpu);
-+
-+ 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->sector = sector;
-+ t->bytes = bytes;
-+ t->action = what;
-+ t->pid = pid;
-+ t->device = bt->dev;
-+ t->cpu = cpu;
-+ t->error = error;
-+ t->pdu_len = pdu_len;
-+
-+ if (pdu_len)
-+ memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
-+ }
-+
-+ local_irq_restore(flags);
-+}
-+
-+EXPORT_SYMBOL_GPL(__blk_add_trace);
-+
-+static struct dentry *blk_tree_root;
-+static struct mutex blk_tree_mutex;
-+static unsigned int root_users;
-+
-+static inline void blk_remove_root(void)
-+{
-+ if (blk_tree_root) {
-+ debugfs_remove(blk_tree_root);
-+ blk_tree_root = NULL;
-+ }
-+}
-+
-+static void blk_remove_tree(struct dentry *dir)
-+{
-+ mutex_lock(&blk_tree_mutex);
-+ debugfs_remove(dir);
-+ blk_remove_root();
-+ if (--root_users == 0)
-+ blk_remove_root();
-+ mutex_unlock(&blk_tree_mutex);
-+}
-+
-+static struct dentry *blk_create_tree(const char *blk_name)
-+{
-+ struct dentry *dir = NULL;
-+
-+ mutex_lock(&blk_tree_mutex);
-+
-+ if (!blk_tree_root) {
-+ blk_tree_root = debugfs_create_dir("block", NULL);
-+ if (!blk_tree_root)
-+ goto err;
-+ }
-+
-+ dir = debugfs_create_dir(blk_name, blk_tree_root);
-+ if (dir)
-+ root_users++;
-+ else
-+ blk_remove_root();
-+
-+err:
-+ mutex_unlock(&blk_tree_mutex);
-+ return dir;
-+}
-+
-+static void blk_trace_cleanup(struct blk_trace *bt)
-+{
-+ relay_close(bt->rchan);
-+ debugfs_remove(bt->dropped_file);
-+ blk_remove_tree(bt->dir);
-+ free_percpu(bt->sequence);
-+ kfree(bt);
-+}
-+
-+static int blk_trace_remove(request_queue_t *q)
-+{
-+ struct blk_trace *bt;
-+
-+ bt = xchg(&q->blk_trace, NULL);
-+ if (!bt)
-+ return -EINVAL;
-+
-+ if (bt->trace_state == Blktrace_setup ||
-+ bt->trace_state == Blktrace_stopped)
-+ blk_trace_cleanup(bt);
-+
-+ return 0;
-+}
-+
-+static int blk_dropped_open(struct inode *inode, struct file *filp)
-+{
-+ filp->private_data = inode->u.generic_ip;
-+
-+ return 0;
-+}
-+
-+static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
-+ size_t count, loff_t *ppos)
-+{
-+ struct blk_trace *bt = filp->private_data;
-+ char buf[16];
-+
-+ snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
-+
-+ return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
-+}
-+
-+static struct file_operations blk_dropped_fops = {
-+ .owner = THIS_MODULE,
-+ .open = blk_dropped_open,
-+ .read = blk_dropped_read,
-+};
-+
-+/*
-+ * 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.
-+ */
-+static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
-+ void *prev_subbuf, size_t prev_padding)
-+{
-+ struct blk_trace *bt;
-+
-+ if (!relay_buf_full(buf))
-+ return 1;
-+
-+ bt = buf->chan->private_data;
-+ atomic_inc(&bt->dropped);
-+ return 0;
-+}
-+
-+static int blk_remove_buf_file_callback(struct dentry *dentry)
-+{
-+ debugfs_remove(dentry);
-+ return 0;
-+}
-+
-+static struct dentry *blk_create_buf_file_callback(const char *filename,
-+ struct dentry *parent,
-+ int mode,
-+ struct rchan_buf *buf,
-+ int *is_global)
-+{
-+ return debugfs_create_file(filename, mode, parent, buf,
-+ &relay_file_operations);
-+}
-+
-+static struct rchan_callbacks blk_relay_callbacks = {
-+ .subbuf_start = blk_subbuf_start_callback,
-+ .create_buf_file = blk_create_buf_file_callback,
-+ .remove_buf_file = blk_remove_buf_file_callback,
-+};
-+
-+/*
-+ * Setup everything required to start tracing
-+ */
-+static int blk_trace_setup(request_queue_t *q, struct block_device *bdev,
-+ char __user *arg)
-+{
-+ 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)
-+ return -EINVAL;
-+
-+ strcpy(buts.name, bdevname(bdev, b));
-+
-+ /*
-+ * 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;
-+
-+ ret = -ENOMEM;
-+ bt = kzalloc(sizeof(*bt), GFP_KERNEL);
-+ if (!bt)
-+ goto err;
-+
-+ bt->sequence = alloc_percpu(unsigned long);
-+ if (!bt->sequence)
-+ goto err;
-+
-+ ret = -ENOENT;
-+ dir = blk_create_tree(buts.name);
-+ if (!dir)
-+ goto err;
-+
-+ bt->dir = dir;
-+ bt->dev = bdev->bd_dev;
-+ atomic_set(&bt->dropped, 0);
-+
-+ ret = -EIO;
-+ bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
-+ if (!bt->dropped_file)
-+ goto err;
-+
-+ bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks);
-+ if (!bt->rchan)
-+ goto err;
-+ bt->rchan->private_data = bt;
-+
-+ 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;
-+ if (!bt->end_lba)
-+ bt->end_lba = -1ULL;
-+
-+ bt->pid = buts.pid;
-+ bt->trace_state = Blktrace_setup;
-+
-+ ret = -EBUSY;
-+ old_bt = xchg(&q->blk_trace, bt);
-+ if (old_bt) {
-+ (void) xchg(&q->blk_trace, old_bt);
-+ goto err;
-+ }
-+
-+ return 0;
-+err:
-+ if (dir)
-+ blk_remove_tree(dir);
-+ if (bt) {
-+ if (bt->dropped_file)
-+ debugfs_remove(bt->dropped_file);
-+ if (bt->sequence)
-+ free_percpu(bt->sequence);
-+ if (bt->rchan)
-+ relay_close(bt->rchan);
-+ kfree(bt);
-+ }
-+ return ret;
-+}
-+
-+static int blk_trace_startstop(request_queue_t *q, int start)
-+{
-+ struct blk_trace *bt;
-+ int ret;
-+
-+ if ((bt = q->blk_trace) == NULL)
-+ return -EINVAL;
-+
-+ /*
-+ * For starting a trace, we can transition from a setup or stopped
-+ * trace. For stopping a trace, the state must be running
-+ */
-+ ret = -EINVAL;
-+ if (start) {
-+ if (bt->trace_state == Blktrace_setup ||
-+ bt->trace_state == Blktrace_stopped) {
-+ blktrace_seq++;
-+ smp_mb();
-+ bt->trace_state = Blktrace_running;
-+ ret = 0;
-+ }
-+ } else {
-+ if (bt->trace_state == Blktrace_running) {
-+ bt->trace_state = Blktrace_stopped;
-+ relay_flush(bt->rchan);
-+ ret = 0;
-+ }
-+ }
-+
-+ return ret;
-+}
-+
-+/**
-+ * blk_trace_ioctl: - handle the ioctls associated with tracing
-+ * @bdev: the block device
-+ * @cmd: the ioctl cmd
-+ * @arg: the argument data, if any
-+ *
-+ **/
-+int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
-+{
-+ request_queue_t *q;
-+ int ret, start = 0;
-+
-+ q = bdev_get_queue(bdev);
-+ if (!q)
-+ return -ENXIO;
-+
-+ down(&bdev->bd_sem);
-+
-+ switch (cmd) {
-+ case BLKTRACESETUP:
-+ ret = blk_trace_setup(q, bdev, arg);
-+ break;
-+ case BLKTRACESTART:
-+ start = 1;
-+ case BLKTRACESTOP:
-+ ret = blk_trace_startstop(q, start);
-+ break;
-+ case BLKTRACETEARDOWN:
-+ ret = blk_trace_remove(q);
-+ break;
-+ default:
-+ ret = -ENOTTY;
-+ break;
-+ }
-+
-+ up(&bdev->bd_sem);
-+ return ret;
-+}
-+
-+/**
-+ * blk_trace_shutdown: - stop and cleanup trace structures
-+ * @q: the request queue associated with the device
-+ *
-+ **/
-+void blk_trace_shutdown(request_queue_t *q)
-+{
-+ 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;
-+}
-+
-+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();
-+}
-+
-+/*
-+ * Call blk_trace_check_cpu_time() on each CPU to calibrate our inter-CPU
-+ * timings
-+ */
-+static void 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);
-+}
-+
-+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);
-+ blk_trace_calibrate_offsets();
-+ blk_trace_set_ht_offsets();
-+
-+ return 0;
-+}
-+
-+module_init(blk_trace_init);
-+
-diff --git a/block/elevator.c b/block/elevator.c
-index 24b702d..0c9fafe 100644
---- a/block/elevator.c
-+++ b/block/elevator.c
-@@ -33,6 +33,7 @@
- #include <linux/init.h>
- #include <linux/compiler.h>
- #include <linux/delay.h>
-+#include <linux/blktrace_api.h>
-
- #include <asm/uaccess.h>
-
-@@ -315,6 +316,8 @@ void elv_insert(request_queue_t *q, stru
- struct list_head *pos;
- unsigned ordseq;
-
-+ blk_add_trace_rq(q, rq, BLK_TA_INSERT);
-+
- rq->q = q;
-
- switch (where) {
-@@ -481,6 +484,7 @@ struct request *elv_next_request(request
- * not be passed by new incoming requests
- */
- rq->flags |= REQ_STARTED;
-+ blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
- }
-
- if (!q->boundary_rq || q->boundary_rq == rq) {
-diff --git a/block/ioctl.c b/block/ioctl.c
-index e110949..7acb56c 100644
---- a/block/ioctl.c
-+++ b/block/ioctl.c
-@@ -5,6 +5,7 @@
- #include <linux/backing-dev.h>
- #include <linux/buffer_head.h>
- #include <linux/smp_lock.h>
-+#include <linux/blktrace_api.h>
- #include <asm/uaccess.h>
-
- static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
-@@ -189,6 +190,11 @@ 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 BLKTRACESTART:
-+ case BLKTRACESTOP:
-+ case BLKTRACESETUP:
-+ case BLKTRACETEARDOWN:
-+ return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
- }
- return -ENOIOCTLCMD;
- }
-diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
-index 0ef2971..7233ab8 100644
---- a/block/ll_rw_blk.c
-+++ b/block/ll_rw_blk.c
-@@ -28,6 +28,7 @@
- #include <linux/writeback.h>
- #include <linux/interrupt.h>
- #include <linux/cpu.h>
-+#include <linux/blktrace_api.h>
-
- /*
- * for max sense size
-@@ -1556,8 +1557,10 @@ 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);
-@@ -1621,14 +1624,21 @@ 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);
- }
-
-@@ -1636,6 +1646,9 @@ 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);
- }
-
-@@ -1758,6 +1771,9 @@ void blk_cleanup_queue(request_queue_t *
- if (q->queue_tags)
- __blk_queue_free_tags(q);
-
-+ if (q->blk_trace)
-+ blk_trace_shutdown(q);
-+
- kmem_cache_free(requestq_cachep, q);
- }
-
-@@ -2109,6 +2125,8 @@ rq_starved:
-
- rq_init(q, rq);
- rq->rl = rl;
-+
-+ blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
- out:
- return rq;
- }
-@@ -2137,6 +2155,8 @@ 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();
-@@ -2190,6 +2210,8 @@ 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);
-
-@@ -2824,6 +2846,8 @@ 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;
-@@ -2839,6 +2863,8 @@ 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;
-
-@@ -2956,6 +2982,7 @@ 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. */
-@@ -2982,6 +3009,8 @@ 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];
-
-@@ -3014,6 +3043,15 @@ end_io:
- */
- blk_partition_remap(bio);
-
-+ if (maxsector != -1)
-+ blk_add_trace_remap(q, bio, old_dev, bio->bi_sector,
-+ 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);
- }
-@@ -3133,6 +3171,8 @@ 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/drivers/block/cciss.c b/drivers/block/cciss.c
-index 0d65394..234048e 100644
---- a/drivers/block/cciss.c
-+++ b/drivers/block/cciss.c
-@@ -38,6 +38,7 @@
- #include <linux/hdreg.h>
- #include <linux/spinlock.h>
- #include <linux/compat.h>
-+#include <linux/blktrace_api.h>
- #include <asm/uaccess.h>
- #include <asm/io.h>
-
-@@ -2331,6 +2332,7 @@ static inline void complete_command( ctl
-
- cmd->rq->completion_data = cmd;
- cmd->rq->errors = status;
-+ blk_add_trace_rq(cmd->rq->q, cmd->rq, BLK_TA_COMPLETE);
- blk_complete_request(cmd->rq);
- }
-
-diff --git a/drivers/md/dm.c b/drivers/md/dm.c
-index 745ca1f..f36613e 100644
---- a/drivers/md/dm.c
-+++ b/drivers/md/dm.c
-@@ -17,6 +17,7 @@
- #include <linux/mempool.h>
- #include <linux/slab.h>
- #include <linux/idr.h>
-+#include <linux/blktrace_api.h>
-
- static const char *_name = DM_NAME;
-
-@@ -334,6 +335,8 @@ static void dec_pending(struct dm_io *io
- /* nudge anyone waiting on suspend queue */
- wake_up(&io->md->wait);
-
-+ blk_add_trace_bio(io->md->queue, io->bio, BLK_TA_COMPLETE);
-+
- bio_endio(io->bio, io->bio->bi_size, io->error);
- free_io(io->md, io);
- }
-@@ -392,6 +395,7 @@ static void __map_bio(struct dm_target *
- struct target_io *tio)
- {
- int r;
-+ sector_t sector;
-
- /*
- * Sanity checks.
-@@ -407,10 +411,17 @@ static void __map_bio(struct dm_target *
- * this io.
- */
- atomic_inc(&tio->io->io_count);
-+ sector = clone->bi_sector;
- r = ti->type->map(ti, clone, &tio->info);
-- if (r > 0)
-+ if (r > 0) {
- /* the bio has been remapped so dispatch it */
-+
-+ blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone,
-+ tio->io->bio->bi_bdev->bd_dev, sector,
-+ clone->bi_sector);
-+
- generic_make_request(clone);
-+ }
-
- else if (r < 0) {
- /* error the io and bail out */
-diff --git a/fs/Kconfig b/fs/Kconfig
-index e9749b0..c8d0a20 100644
---- a/fs/Kconfig
-+++ b/fs/Kconfig
-@@ -859,18 +859,6 @@ config RAMFS
- To compile this as a module, choose M here: the module will be called
- ramfs.
-
--config RELAYFS_FS
-- tristate "Relayfs file system support"
-- ---help---
-- Relayfs is a high-speed data relay filesystem designed to provide
-- an efficient mechanism for tools and facilities to relay large
-- amounts of data from kernel space to user space.
--
-- To compile this code as a module, choose M here: the module will be
-- called relayfs.
--
-- If unsure, say N.
--
- config CONFIGFS_FS
- tristate "Userspace-driven configuration filesystem (EXPERIMENTAL)"
- depends on EXPERIMENTAL
-diff --git a/fs/Makefile b/fs/Makefile
-index 1db7113..080b386 100644
---- a/fs/Makefile
-+++ b/fs/Makefile
-@@ -91,7 +91,6 @@ obj-$(CONFIG_AUTOFS4_FS) += autofs4/
- obj-$(CONFIG_ADFS_FS) += adfs/
- obj-$(CONFIG_FUSE_FS) += fuse/
- obj-$(CONFIG_UDF_FS) += udf/
--obj-$(CONFIG_RELAYFS_FS) += relayfs/
- obj-$(CONFIG_SUN_OPENPROMFS) += openpromfs/
- obj-$(CONFIG_JFS_FS) += jfs/
- obj-$(CONFIG_XFS_FS) += xfs/
-diff --git a/fs/bio.c b/fs/bio.c
-index 1f3bb50..0dd0d81 100644
---- a/fs/bio.c
-+++ b/fs/bio.c
-@@ -25,6 +25,7 @@
- #include <linux/module.h>
- #include <linux/mempool.h>
- #include <linux/workqueue.h>
-+#include <linux/blktrace_api.h>
- #include <scsi/sg.h> /* for struct sg_iovec */
-
- #define BIO_POOL_SIZE 256
-@@ -1095,6 +1096,9 @@ struct bio_pair *bio_split(struct bio *b
- if (!bp)
- return bp;
-
-+ blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi,
-+ bi->bi_sector + first_sectors);
-+
- BUG_ON(bi->bi_vcnt != 1);
- BUG_ON(bi->bi_idx != 0);
- atomic_set(&bp->cnt, 3);
-diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
-index c666769..7c031f0 100644
---- a/fs/compat_ioctl.c
-+++ b/fs/compat_ioctl.c
-@@ -72,6 +72,7 @@
- #include <linux/i2c-dev.h>
- #include <linux/wireless.h>
- #include <linux/atalk.h>
-+#include <linux/blktrace_api.h>
-
- #include <net/sock.h> /* siocdevprivate_ioctl */
- #include <net/bluetooth/bluetooth.h>
-diff --git a/fs/relayfs/Makefile b/fs/relayfs/Makefile
-deleted file mode 100644
-index e76e182..0000000
---- a/fs/relayfs/Makefile
-+++ /dev/null
-@@ -1,4 +0,0 @@
--obj-$(CONFIG_RELAYFS_FS) += relayfs.o
--
--relayfs-y := relay.o inode.o buffers.o
--
-diff --git a/fs/relayfs/buffers.c b/fs/relayfs/buffers.c
-deleted file mode 100644
-index 1018781..0000000
---- a/fs/relayfs/buffers.c
-+++ /dev/null
-@@ -1,190 +0,0 @@
--/*
-- * RelayFS buffer management code.
-- *
-- * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
-- * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
-- *
-- * This file is released under the GPL.
-- */
--
--#include <linux/module.h>
--#include <linux/vmalloc.h>
--#include <linux/mm.h>
--#include <linux/relayfs_fs.h>
--#include "relay.h"
--#include "buffers.h"
--
--/*
-- * close() vm_op implementation for relayfs file mapping.
-- */
--static void relay_file_mmap_close(struct vm_area_struct *vma)
--{
-- struct rchan_buf *buf = vma->vm_private_data;
-- buf->chan->cb->buf_unmapped(buf, vma->vm_file);
--}
--
--/*
-- * nopage() vm_op implementation for relayfs file mapping.
-- */
--static struct page *relay_buf_nopage(struct vm_area_struct *vma,
-- unsigned long address,
-- int *type)
--{
-- struct page *page;
-- struct rchan_buf *buf = vma->vm_private_data;
-- unsigned long offset = address - vma->vm_start;
--
-- if (address > vma->vm_end)
-- return NOPAGE_SIGBUS; /* Disallow mremap */
-- if (!buf)
-- return NOPAGE_OOM;
--
-- page = vmalloc_to_page(buf->start + offset);
-- if (!page)
-- return NOPAGE_OOM;
-- get_page(page);
--
-- if (type)
-- *type = VM_FAULT_MINOR;
--
-- return page;
--}
--
--/*
-- * vm_ops for relay file mappings.
-- */
--static struct vm_operations_struct relay_file_mmap_ops = {
-- .nopage = relay_buf_nopage,
-- .close = relay_file_mmap_close,
--};
--
--/**
-- * relay_mmap_buf: - mmap channel buffer to process address space
-- * @buf: relay channel buffer
-- * @vma: vm_area_struct describing memory to be mapped
-- *
-- * Returns 0 if ok, negative on error
-- *
-- * Caller should already have grabbed mmap_sem.
-- */
--int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
--{
-- unsigned long length = vma->vm_end - vma->vm_start;
-- struct file *filp = vma->vm_file;
--
-- if (!buf)
-- return -EBADF;
--
-- if (length != (unsigned long)buf->chan->alloc_size)
-- return -EINVAL;
--
-- vma->vm_ops = &relay_file_mmap_ops;
-- vma->vm_private_data = buf;
-- buf->chan->cb->buf_mapped(buf, filp);
--
-- return 0;
--}
--
--/**
-- * relay_alloc_buf - allocate a channel buffer
-- * @buf: the buffer struct
-- * @size: total size of the buffer
-- *
-- * Returns a pointer to the resulting buffer, NULL if unsuccessful
-- */
--static void *relay_alloc_buf(struct rchan_buf *buf, unsigned long size)
--{
-- void *mem;
-- unsigned int i, j, n_pages;
--
-- size = PAGE_ALIGN(size);
-- n_pages = size >> PAGE_SHIFT;
--
-- buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL);
-- if (!buf->page_array)
-- return NULL;
--
-- for (i = 0; i < n_pages; i++) {
-- buf->page_array[i] = alloc_page(GFP_KERNEL);
-- if (unlikely(!buf->page_array[i]))
-- goto depopulate;
-- }
-- mem = vmap(buf->page_array, n_pages, VM_MAP, PAGE_KERNEL);
-- if (!mem)
-- goto depopulate;
--
-- memset(mem, 0, size);
-- buf->page_count = n_pages;
-- return mem;
--
--depopulate:
-- for (j = 0; j < i; j++)
-- __free_page(buf->page_array[j]);
-- kfree(buf->page_array);
-- return NULL;
--}
--
--/**
-- * relay_create_buf - allocate and initialize a channel buffer
-- * @alloc_size: size of the buffer to allocate
-- * @n_subbufs: number of sub-buffers in the channel
-- *
-- * Returns channel buffer if successful, NULL otherwise
-- */
--struct rchan_buf *relay_create_buf(struct rchan *chan)
--{
-- struct rchan_buf *buf = kcalloc(1, sizeof(struct rchan_buf), GFP_KERNEL);
-- if (!buf)
-- return NULL;
--
-- buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL);
-- if (!buf->padding)
-- goto free_buf;
--
-- buf->start = relay_alloc_buf(buf, chan->alloc_size);
-- if (!buf->start)
-- goto free_buf;
--
-- buf->chan = chan;
-- kref_get(&buf->chan->kref);
-- return buf;
--
--free_buf:
-- kfree(buf->padding);
-- kfree(buf);
-- return NULL;
--}
--
--/**
-- * relay_destroy_buf - destroy an rchan_buf struct and associated buffer
-- * @buf: the buffer struct
-- */
--void relay_destroy_buf(struct rchan_buf *buf)
--{
-- struct rchan *chan = buf->chan;
-- unsigned int i;
--
-- if (likely(buf->start)) {
-- vunmap(buf->start);
-- for (i = 0; i < buf->page_count; i++)
-- __free_page(buf->page_array[i]);
-- kfree(buf->page_array);
-- }
-- kfree(buf->padding);
-- kfree(buf);
-- kref_put(&chan->kref, relay_destroy_channel);
--}
--
--/**
-- * relay_remove_buf - remove a channel buffer
-- *
-- * Removes the file from the relayfs fileystem, which also frees the
-- * rchan_buf_struct and the channel buffer. Should only be called from
-- * kref_put().
-- */
--void relay_remove_buf(struct kref *kref)
--{
-- struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);
-- buf->chan->cb->remove_buf_file(buf->dentry);
-- relay_destroy_buf(buf);
--}
-diff --git a/fs/relayfs/buffers.h b/fs/relayfs/buffers.h
-deleted file mode 100644
-index 37a1249..0000000
---- a/fs/relayfs/buffers.h
-+++ /dev/null
-@@ -1,12 +0,0 @@
--#ifndef _BUFFERS_H
--#define _BUFFERS_H
--
--/* This inspired by rtai/shmem */
--#define FIX_SIZE(x) (((x) - 1) & PAGE_MASK) + PAGE_SIZE
--
--extern int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma);
--extern struct rchan_buf *relay_create_buf(struct rchan *chan);
--extern void relay_destroy_buf(struct rchan_buf *buf);
--extern void relay_remove_buf(struct kref *kref);
--
--#endif/* _BUFFERS_H */
-diff --git a/fs/relayfs/inode.c b/fs/relayfs/inode.c
-deleted file mode 100644
-index 3835230..0000000
---- a/fs/relayfs/inode.c
-+++ /dev/null
-@@ -1,581 +0,0 @@
--/*
-- * VFS-related code for RelayFS, a high-speed data relay filesystem.
-- *
-- * Copyright (C) 2003-2005 - Tom Zanussi <zanussi@us.ibm.com>, IBM Corp
-- * Copyright (C) 2003-2005 - Karim Yaghmour <karim@opersys.com>
-- *
-- * Based on ramfs, Copyright (C) 2002 - Linus Torvalds
-- *
-- * This file is released under the GPL.
-- */
--
--#include <linux/module.h>
--#include <linux/fs.h>
--#include <linux/mount.h>
--#include <linux/pagemap.h>
--#include <linux/init.h>
--#include <linux/string.h>
--#include <linux/backing-dev.h>
--#include <linux/namei.h>
--#include <linux/poll.h>
--#include <linux/relayfs_fs.h>
--#include "relay.h"
--#include "buffers.h"
--
--#define RELAYFS_MAGIC 0xF0B4A981
--
--static struct vfsmount * relayfs_mount;
--static int relayfs_mount_count;
--
--static struct backing_dev_info relayfs_backing_dev_info = {
-- .ra_pages = 0, /* No readahead */
-- .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
--};
--
--static struct inode *relayfs_get_inode(struct super_block *sb,
-- int mode,
-- struct file_operations *fops,
-- void *data)
--{
-- struct inode *inode;
--
-- inode = new_inode(sb);
-- if (!inode)
-- return NULL;
--
-- inode->i_mode = mode;
-- inode->i_uid = 0;
-- inode->i_gid = 0;
-- inode->i_blksize = PAGE_CACHE_SIZE;
-- inode->i_blocks = 0;
-- inode->i_mapping->backing_dev_info = &relayfs_backing_dev_info;
-- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-- switch (mode & S_IFMT) {
-- case S_IFREG:
-- inode->i_fop = fops;
-- if (data)
-- inode->u.generic_ip = data;
-- break;
-- case S_IFDIR:
-- inode->i_op = &simple_dir_inode_operations;
-- inode->i_fop = &simple_dir_operations;
--
-- /* directory inodes start off with i_nlink == 2 (for "." entry) */
-- inode->i_nlink++;
-- break;
-- default:
-- break;
-- }
--
-- return inode;
--}
--
--/**
-- * relayfs_create_entry - create a relayfs directory or file
-- * @name: the name of the file to create
-- * @parent: parent directory
-- * @mode: mode
-- * @fops: file operations to use for the file
-- * @data: user-associated data for this file
-- *
-- * Returns the new dentry, NULL on failure
-- *
-- * Creates a file or directory with the specifed permissions.
-- */
--static struct dentry *relayfs_create_entry(const char *name,
-- struct dentry *parent,
-- int mode,
-- struct file_operations *fops,
-- void *data)
--{
-- struct dentry *d;
-- struct inode *inode;
-- int error = 0;
--
-- BUG_ON(!name || !(S_ISREG(mode) || S_ISDIR(mode)));
--
-- error = simple_pin_fs("relayfs", &relayfs_mount, &relayfs_mount_count);
-- if (error) {
-- printk(KERN_ERR "Couldn't mount relayfs: errcode %d\n", error);
-- return NULL;
-- }
--
-- if (!parent && relayfs_mount && relayfs_mount->mnt_sb)
-- parent = relayfs_mount->mnt_sb->s_root;
--
-- if (!parent) {
-- simple_release_fs(&relayfs_mount, &relayfs_mount_count);
-- return NULL;
-- }
--
-- parent = dget(parent);
-- mutex_lock(&parent->d_inode->i_mutex);
-- d = lookup_one_len(name, parent, strlen(name));
-- if (IS_ERR(d)) {
-- d = NULL;
-- goto release_mount;
-- }
--
-- if (d->d_inode) {
-- d = NULL;
-- goto release_mount;
-- }
--
-- inode = relayfs_get_inode(parent->d_inode->i_sb, mode, fops, data);
-- if (!inode) {
-- d = NULL;
-- goto release_mount;
-- }
--
-- d_instantiate(d, inode);
-- dget(d); /* Extra count - pin the dentry in core */
--
-- if (S_ISDIR(mode))
-- parent->d_inode->i_nlink++;
--
-- goto exit;
--
--release_mount:
-- simple_release_fs(&relayfs_mount, &relayfs_mount_count);
--
--exit:
-- mutex_unlock(&parent->d_inode->i_mutex);
-- dput(parent);
-- return d;
--}
--
--/**
-- * relayfs_create_file - create a file in the relay filesystem
-- * @name: the name of the file to create
-- * @parent: parent directory
-- * @mode: mode, if not specied the default perms are used
-- * @fops: file operations to use for the file
-- * @data: user-associated data for this file
-- *
-- * Returns file dentry if successful, NULL otherwise.
-- *
-- * The file will be created user r on behalf of current user.
-- */
--struct dentry *relayfs_create_file(const char *name,
-- struct dentry *parent,
-- int mode,
-- struct file_operations *fops,
-- void *data)
--{
-- BUG_ON(!fops);
--
-- if (!mode)
-- mode = S_IRUSR;
-- mode = (mode & S_IALLUGO) | S_IFREG;
--
-- return relayfs_create_entry(name, parent, mode, fops, data);
--}
--
--/**
-- * relayfs_create_dir - create a directory in the relay filesystem
-- * @name: the name of the directory to create
-- * @parent: parent directory, NULL if parent should be fs root
-- *
-- * Returns directory dentry if successful, NULL otherwise.
-- *
-- * The directory will be created world rwx on behalf of current user.
-- */
--struct dentry *relayfs_create_dir(const char *name, struct dentry *parent)
--{
-- int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
-- return relayfs_create_entry(name, parent, mode, NULL, NULL);
--}
--
--/**
-- * relayfs_remove - remove a file or directory in the relay filesystem
-- * @dentry: file or directory dentry
-- *
-- * Returns 0 if successful, negative otherwise.
-- */
--int relayfs_remove(struct dentry *dentry)
--{
-- struct dentry *parent;
-- int error = 0;
--
-- if (!dentry)
-- return -EINVAL;
-- parent = dentry->d_parent;
-- if (!parent)
-- return -EINVAL;
--
-- parent = dget(parent);
-- mutex_lock(&parent->d_inode->i_mutex);
-- if (dentry->d_inode) {
-- if (S_ISDIR(dentry->d_inode->i_mode))
-- error = simple_rmdir(parent->d_inode, dentry);
-- else
-- error = simple_unlink(parent->d_inode, dentry);
-- if (!error)
-- d_delete(dentry);
-- }
-- if (!error)
-- dput(dentry);
-- mutex_unlock(&parent->d_inode->i_mutex);
-- dput(parent);
--
-- if (!error)
-- simple_release_fs(&relayfs_mount, &relayfs_mount_count);
--
-- return error;
--}
--
--/**
-- * relayfs_remove_file - remove a file from relay filesystem
-- * @dentry: directory dentry
-- *
-- * Returns 0 if successful, negative otherwise.
-- */
--int relayfs_remove_file(struct dentry *dentry)
--{
-- return relayfs_remove(dentry);
--}
--
--/**
-- * relayfs_remove_dir - remove a directory in the relay filesystem
-- * @dentry: directory dentry
-- *
-- * Returns 0 if successful, negative otherwise.
-- */
--int relayfs_remove_dir(struct dentry *dentry)
--{
-- return relayfs_remove(dentry);
--}
--
--/**
-- * relay_file_open - open file op for relay files
-- * @inode: the inode
-- * @filp: the file
-- *
-- * Increments the channel buffer refcount.
-- */
--static int relay_file_open(struct inode *inode, struct file *filp)
--{
-- struct rchan_buf *buf = inode->u.generic_ip;
-- kref_get(&buf->kref);
-- filp->private_data = buf;
--
-- return 0;
--}
--
--/**
-- * relay_file_mmap - mmap file op for relay files
-- * @filp: the file
-- * @vma: the vma describing what to map
-- *
-- * Calls upon relay_mmap_buf to map the file into user space.
-- */
--static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma)
--{
-- struct rchan_buf *buf = filp->private_data;
-- return relay_mmap_buf(buf, vma);
--}
--
--/**
-- * relay_file_poll - poll file op for relay files
-- * @filp: the file
-- * @wait: poll table
-- *
-- * Poll implemention.
-- */
--static unsigned int relay_file_poll(struct file *filp, poll_table *wait)
--{
-- unsigned int mask = 0;
-- struct rchan_buf *buf = filp->private_data;
--
-- if (buf->finalized)
-- return POLLERR;
--
-- if (filp->f_mode & FMODE_READ) {
-- poll_wait(filp, &buf->read_wait, wait);
-- if (!relay_buf_empty(buf))
-- mask |= POLLIN | POLLRDNORM;
-- }
--
-- return mask;
--}
--
--/**
-- * relay_file_release - release file op for relay files
-- * @inode: the inode
-- * @filp: the file
-- *
-- * Decrements the channel refcount, as the filesystem is
-- * no longer using it.
-- */
--static int relay_file_release(struct inode *inode, struct file *filp)
--{
-- struct rchan_buf *buf = filp->private_data;
-- kref_put(&buf->kref, relay_remove_buf);
--
-- return 0;
--}
--
--/**
-- * relay_file_read_consume - update the consumed count for the buffer
-- */
--static void relay_file_read_consume(struct rchan_buf *buf,
-- size_t read_pos,
-- size_t bytes_consumed)
--{
-- size_t subbuf_size = buf->chan->subbuf_size;
-- size_t n_subbufs = buf->chan->n_subbufs;
-- size_t read_subbuf;
--
-- if (buf->bytes_consumed + bytes_consumed > subbuf_size) {
-- relay_subbufs_consumed(buf->chan, buf->cpu, 1);
-- buf->bytes_consumed = 0;
-- }
--
-- buf->bytes_consumed += bytes_consumed;
-- read_subbuf = read_pos / buf->chan->subbuf_size;
-- if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) {
-- if ((read_subbuf == buf->subbufs_produced % n_subbufs) &&
-- (buf->offset == subbuf_size))
-- return;
-- relay_subbufs_consumed(buf->chan, buf->cpu, 1);
-- buf->bytes_consumed = 0;
-- }
--}
--
--/**
-- * relay_file_read_avail - boolean, are there unconsumed bytes available?
-- */
--static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
--{
-- size_t bytes_produced, bytes_consumed, write_offset;
-- size_t subbuf_size = buf->chan->subbuf_size;
-- size_t n_subbufs = buf->chan->n_subbufs;
-- size_t produced = buf->subbufs_produced % n_subbufs;
-- size_t consumed = buf->subbufs_consumed % n_subbufs;
--
-- write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
--
-- if (consumed > produced) {
-- if ((produced > n_subbufs) &&
-- (produced + n_subbufs - consumed <= n_subbufs))
-- produced += n_subbufs;
-- } else if (consumed == produced) {
-- if (buf->offset > subbuf_size) {
-- produced += n_subbufs;
-- if (buf->subbufs_produced == buf->subbufs_consumed)
-- consumed += n_subbufs;
-- }
-- }
--
-- if (buf->offset > subbuf_size)
-- bytes_produced = (produced - 1) * subbuf_size + write_offset;
-- else
-- bytes_produced = produced * subbuf_size + write_offset;
-- bytes_consumed = consumed * subbuf_size + buf->bytes_consumed;
--
-- if (bytes_produced == bytes_consumed)
-- return 0;
--
-- relay_file_read_consume(buf, read_pos, 0);
--
-- return 1;
--}
--
--/**
-- * relay_file_read_subbuf_avail - return bytes available in sub-buffer
-- */
--static size_t relay_file_read_subbuf_avail(size_t read_pos,
-- struct rchan_buf *buf)
--{
-- size_t padding, avail = 0;
-- size_t read_subbuf, read_offset, write_subbuf, write_offset;
-- size_t subbuf_size = buf->chan->subbuf_size;
--
-- write_subbuf = (buf->data - buf->start) / subbuf_size;
-- write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
-- read_subbuf = read_pos / subbuf_size;
-- read_offset = read_pos % subbuf_size;
-- padding = buf->padding[read_subbuf];
--
-- if (read_subbuf == write_subbuf) {
-- if (read_offset + padding < write_offset)
-- avail = write_offset - (read_offset + padding);
-- } else
-- avail = (subbuf_size - padding) - read_offset;
--
-- return avail;
--}
--
--/**
-- * relay_file_read_start_pos - find the first available byte to read
-- *
-- * If the read_pos is in the middle of padding, return the
-- * position of the first actually available byte, otherwise
-- * return the original value.
-- */
--static size_t relay_file_read_start_pos(size_t read_pos,
-- struct rchan_buf *buf)
--{
-- size_t read_subbuf, padding, padding_start, padding_end;
-- size_t subbuf_size = buf->chan->subbuf_size;
-- size_t n_subbufs = buf->chan->n_subbufs;
--
-- read_subbuf = read_pos / subbuf_size;
-- padding = buf->padding[read_subbuf];
-- padding_start = (read_subbuf + 1) * subbuf_size - padding;
-- padding_end = (read_subbuf + 1) * subbuf_size;
-- if (read_pos >= padding_start && read_pos < padding_end) {
-- read_subbuf = (read_subbuf + 1) % n_subbufs;
-- read_pos = read_subbuf * subbuf_size;
-- }
--
-- return read_pos;
--}
--
--/**
-- * relay_file_read_end_pos - return the new read position
-- */
--static size_t relay_file_read_end_pos(struct rchan_buf *buf,
-- size_t read_pos,
-- size_t count)
--{
-- size_t read_subbuf, padding, end_pos;
-- size_t subbuf_size = buf->chan->subbuf_size;
-- size_t n_subbufs = buf->chan->n_subbufs;
--
-- read_subbuf = read_pos / subbuf_size;
-- padding = buf->padding[read_subbuf];
-- if (read_pos % subbuf_size + count + padding == subbuf_size)
-- end_pos = (read_subbuf + 1) * subbuf_size;
-- else
-- end_pos = read_pos + count;
-- if (end_pos >= subbuf_size * n_subbufs)
-- end_pos = 0;
--
-- return end_pos;
--}
--
--/**
-- * relay_file_read - read file op for relay files
-- * @filp: the file
-- * @buffer: the userspace buffer
-- * @count: number of bytes to read
-- * @ppos: position to read from
-- *
-- * Reads count bytes or the number of bytes available in the
-- * current sub-buffer being read, whichever is smaller.
-- */
--static ssize_t relay_file_read(struct file *filp,
-- char __user *buffer,
-- size_t count,
-- loff_t *ppos)
--{
-- struct rchan_buf *buf = filp->private_data;
-- struct inode *inode = filp->f_dentry->d_inode;
-- size_t read_start, avail;
-- ssize_t ret = 0;
-- void *from;
--
-- mutex_lock(&inode->i_mutex);
-- if(!relay_file_read_avail(buf, *ppos))
-- goto out;
--
-- read_start = relay_file_read_start_pos(*ppos, buf);
-- avail = relay_file_read_subbuf_avail(read_start, buf);
-- if (!avail)
-- goto out;
--
-- from = buf->start + read_start;
-- ret = count = min(count, avail);
-- if (copy_to_user(buffer, from, count)) {
-- ret = -EFAULT;
-- goto out;
-- }
-- relay_file_read_consume(buf, read_start, count);
-- *ppos = relay_file_read_end_pos(buf, read_start, count);
--out:
-- mutex_unlock(&inode->i_mutex);
-- return ret;
--}
--
--struct file_operations relay_file_operations = {
-- .open = relay_file_open,
-- .poll = relay_file_poll,
-- .mmap = relay_file_mmap,
-- .read = relay_file_read,
-- .llseek = no_llseek,
-- .release = relay_file_release,
--};
--
--static struct super_operations relayfs_ops = {
-- .statfs = simple_statfs,
-- .drop_inode = generic_delete_inode,
--};
--
--static int relayfs_fill_super(struct super_block * sb, void * data, int silent)
--{
-- struct inode *inode;
-- struct dentry *root;
-- int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
--
-- sb->s_blocksize = PAGE_CACHE_SIZE;
-- sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
-- sb->s_magic = RELAYFS_MAGIC;
-- sb->s_op = &relayfs_ops;
-- inode = relayfs_get_inode(sb, mode, NULL, NULL);
--
-- if (!inode)
-- return -ENOMEM;
--
-- root = d_alloc_root(inode);
-- if (!root) {
-- iput(inode);
-- return -ENOMEM;
-- }
-- sb->s_root = root;
--
-- return 0;
--}
--
--static struct super_block * relayfs_get_sb(struct file_system_type *fs_type,
-- int flags, const char *dev_name,
-- void *data)
--{
-- return get_sb_single(fs_type, flags, data, relayfs_fill_super);
--}
--
--static struct file_system_type relayfs_fs_type = {
-- .owner = THIS_MODULE,
-- .name = "relayfs",
-- .get_sb = relayfs_get_sb,
-- .kill_sb = kill_litter_super,
--};
--
--static int __init init_relayfs_fs(void)
--{
-- return register_filesystem(&relayfs_fs_type);
--}
--
--static void __exit exit_relayfs_fs(void)
--{
--
--
--
--
--
-- unregister_filesystem(&relayfs_fs_type);
--}
--
--module_init(init_relayfs_fs)
--module_exit(exit_relayfs_fs)
--
--EXPORT_SYMBOL_GPL(relay_file_operations);
--EXPORT_SYMBOL_GPL(relayfs_create_dir);
--EXPORT_SYMBOL_GPL(relayfs_remove_dir);
--EXPORT_SYMBOL_GPL(relayfs_create_file);
--EXPORT_SYMBOL_GPL(relayfs_remove_file);
--
--MODULE_AUTHOR("Tom Zanussi <zanussi@us.ibm.com> and Karim Yaghmour <karim@opersys.com>");
--MODULE_DESCRIPTION("Relay Filesystem");
--MODULE_LICENSE("GPL");
--
-diff --git a/fs/relayfs/relay.c b/fs/relayfs/relay.c
-deleted file mode 100644
-index abf3cea..0000000
---- a/fs/relayfs/relay.c
-+++ /dev/null
-@@ -1,482 +0,0 @@
--/*
-- * Public API and common code for RelayFS.
-- *
-- * See Documentation/filesystems/relayfs.txt for an overview of relayfs.
-- *
-- * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
-- * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
-- *
-- * This file is released under the GPL.
-- */
--
--#include <linux/errno.h>
--#include <linux/stddef.h>
--#include <linux/slab.h>
--#include <linux/module.h>
--#include <linux/string.h>
--#include <linux/relayfs_fs.h>
--#include "relay.h"
--#include "buffers.h"
--
--/**
-- * relay_buf_empty - boolean, is the channel buffer empty?
-- * @buf: channel buffer
-- *
-- * Returns 1 if the buffer is empty, 0 otherwise.
-- */
--int relay_buf_empty(struct rchan_buf *buf)
--{
-- return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1;
--}
--
--/**
-- * relay_buf_full - boolean, is the channel buffer full?
-- * @buf: channel buffer
-- *
-- * Returns 1 if the buffer is full, 0 otherwise.
-- */
--int relay_buf_full(struct rchan_buf *buf)
--{
-- size_t ready = buf->subbufs_produced - buf->subbufs_consumed;
-- return (ready >= buf->chan->n_subbufs) ? 1 : 0;
--}
--
--/*
-- * High-level relayfs kernel API and associated functions.
-- */
--
--/*
-- * rchan_callback implementations defining default channel behavior. Used
-- * in place of corresponding NULL values in client callback struct.
-- */
--
--/*
-- * subbuf_start() default callback. Does nothing.
-- */
--static int subbuf_start_default_callback (struct rchan_buf *buf,
-- void *subbuf,
-- void *prev_subbuf,
-- size_t prev_padding)
--{
-- if (relay_buf_full(buf))
-- return 0;
--
-- return 1;
--}
--
--/*
-- * buf_mapped() default callback. Does nothing.
-- */
--static void buf_mapped_default_callback(struct rchan_buf *buf,
-- struct file *filp)
--{
--}
--
--/*
-- * buf_unmapped() default callback. Does nothing.
-- */
--static void buf_unmapped_default_callback(struct rchan_buf *buf,
-- struct file *filp)
--{
--}
--
--/*
-- * create_buf_file_create() default callback. Creates file to represent buf.
-- */
--static struct dentry *create_buf_file_default_callback(const char *filename,
-- struct dentry *parent,
-- int mode,
-- struct rchan_buf *buf,
-- int *is_global)
--{
-- return relayfs_create_file(filename, parent, mode,
-- &relay_file_operations, buf);
--}
--
--/*
-- * remove_buf_file() default callback. Removes file representing relay buffer.
-- */
--static int remove_buf_file_default_callback(struct dentry *dentry)
--{
-- return relayfs_remove(dentry);
--}
--
--/* relay channel default callbacks */
--static struct rchan_callbacks default_channel_callbacks = {
-- .subbuf_start = subbuf_start_default_callback,
-- .buf_mapped = buf_mapped_default_callback,
-- .buf_unmapped = buf_unmapped_default_callback,
-- .create_buf_file = create_buf_file_default_callback,
-- .remove_buf_file = remove_buf_file_default_callback,
--};
--
--/**
-- * wakeup_readers - wake up readers waiting on a channel
-- * @private: the channel buffer
-- *
-- * This is the work function used to defer reader waking. The
-- * reason waking is deferred is that calling directly from write
-- * causes problems if you're writing from say the scheduler.
-- */
--static void wakeup_readers(void *private)
--{
-- struct rchan_buf *buf = private;
-- wake_up_interruptible(&buf->read_wait);
--}
--
--/**
-- * __relay_reset - reset a channel buffer
-- * @buf: the channel buffer
-- * @init: 1 if this is a first-time initialization
-- *
-- * See relay_reset for description of effect.
-- */
--static inline void __relay_reset(struct rchan_buf *buf, unsigned int init)
--{
-- size_t i;
--
-- if (init) {
-- init_waitqueue_head(&buf->read_wait);
-- kref_init(&buf->kref);
-- INIT_WORK(&buf->wake_readers, NULL, NULL);
-- } else {
-- cancel_delayed_work(&buf->wake_readers);
-- flush_scheduled_work();
-- }
--
-- buf->subbufs_produced = 0;
-- buf->subbufs_consumed = 0;
-- buf->bytes_consumed = 0;
-- buf->finalized = 0;
-- buf->data = buf->start;
-- buf->offset = 0;
--
-- for (i = 0; i < buf->chan->n_subbufs; i++)
-- buf->padding[i] = 0;
--
-- buf->chan->cb->subbuf_start(buf, buf->data, NULL, 0);
--}
--
--/**
-- * relay_reset - reset the channel
-- * @chan: the channel
-- *
-- * This has the effect of erasing all data from all channel buffers
-- * and restarting the channel in its initial state. The buffers
-- * are not freed, so any mappings are still in effect.
-- *
-- * NOTE: Care should be taken that the channel isn't actually
-- * being used by anything when this call is made.
-- */
--void relay_reset(struct rchan *chan)
--{
-- unsigned int i;
-- struct rchan_buf *prev = NULL;
--
-- if (!chan)
-- return;
--
-- for (i = 0; i < NR_CPUS; i++) {
-- if (!chan->buf[i] || chan->buf[i] == prev)
-- break;
-- __relay_reset(chan->buf[i], 0);
-- prev = chan->buf[i];
-- }
--}
--
--/**
-- * relay_open_buf - create a new channel buffer in relayfs
-- *
-- * Internal - used by relay_open().
-- */
--static struct rchan_buf *relay_open_buf(struct rchan *chan,
-- const char *filename,
-- struct dentry *parent,
-- int *is_global)
--{
-- struct rchan_buf *buf;
-- struct dentry *dentry;
--
-- if (*is_global)
-- return chan->buf[0];
--
-- buf = relay_create_buf(chan);
-- if (!buf)
-- return NULL;
--
-- /* Create file in fs */
-- dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR,
-- buf, is_global);
-- if (!dentry) {
-- relay_destroy_buf(buf);
-- return NULL;
-- }
--
-- buf->dentry = dentry;
-- __relay_reset(buf, 1);
--
-- return buf;
--}
--
--/**
-- * relay_close_buf - close a channel buffer
-- * @buf: channel buffer
-- *
-- * Marks the buffer finalized and restores the default callbacks.
-- * The channel buffer and channel buffer data structure are then freed
-- * automatically when the last reference is given up.
-- */
--static inline void relay_close_buf(struct rchan_buf *buf)
--{
-- buf->finalized = 1;
-- buf->chan->cb = &default_channel_callbacks;
-- cancel_delayed_work(&buf->wake_readers);
-- flush_scheduled_work();
-- kref_put(&buf->kref, relay_remove_buf);
--}
--
--static inline void setup_callbacks(struct rchan *chan,
-- struct rchan_callbacks *cb)
--{
-- if (!cb) {
-- chan->cb = &default_channel_callbacks;
-- return;
-- }
--
-- if (!cb->subbuf_start)
-- cb->subbuf_start = subbuf_start_default_callback;
-- if (!cb->buf_mapped)
-- cb->buf_mapped = buf_mapped_default_callback;
-- if (!cb->buf_unmapped)
-- cb->buf_unmapped = buf_unmapped_default_callback;
-- if (!cb->create_buf_file)
-- cb->create_buf_file = create_buf_file_default_callback;
-- if (!cb->remove_buf_file)
-- cb->remove_buf_file = remove_buf_file_default_callback;
-- chan->cb = cb;
--}
--
--/**
-- * relay_open - create a new relayfs channel
-- * @base_filename: base name of files to create
-- * @parent: dentry of parent directory, NULL for root directory
-- * @subbuf_size: size of sub-buffers
-- * @n_subbufs: number of sub-buffers
-- * @cb: client callback functions
-- *
-- * Returns channel pointer if successful, NULL otherwise.
-- *
-- * Creates a channel buffer for each cpu using the sizes and
-- * attributes specified. The created channel buffer files
-- * will be named base_filename0...base_filenameN-1. File
-- * permissions will be S_IRUSR.
-- */
--struct rchan *relay_open(const char *base_filename,
-- struct dentry *parent,
-- size_t subbuf_size,
-- size_t n_subbufs,
-- struct rchan_callbacks *cb)
--{
-- unsigned int i;
-- struct rchan *chan;
-- char *tmpname;
-- int is_global = 0;
--
-- if (!base_filename)
-- return NULL;
--
-- if (!(subbuf_size && n_subbufs))
-- return NULL;
--
-- chan = kcalloc(1, sizeof(struct rchan), GFP_KERNEL);
-- if (!chan)
-- return NULL;
--
-- chan->version = RELAYFS_CHANNEL_VERSION;
-- chan->n_subbufs = n_subbufs;
-- chan->subbuf_size = subbuf_size;
-- chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs);
-- setup_callbacks(chan, cb);
-- kref_init(&chan->kref);
--
-- tmpname = kmalloc(NAME_MAX + 1, GFP_KERNEL);
-- if (!tmpname)
-- goto free_chan;
--
-- for_each_online_cpu(i) {
-- sprintf(tmpname, "%s%d", base_filename, i);
-- chan->buf[i] = relay_open_buf(chan, tmpname, parent,
-- &is_global);
-- chan->buf[i]->cpu = i;
-- if (!chan->buf[i])
-- goto free_bufs;
-- }
--
-- kfree(tmpname);
-- return chan;
--
--free_bufs:
-- for (i = 0; i < NR_CPUS; i++) {
-- if (!chan->buf[i])
-- break;
-- relay_close_buf(chan->buf[i]);
-- if (is_global)
-- break;
-- }
-- kfree(tmpname);
--
--free_chan:
-- kref_put(&chan->kref, relay_destroy_channel);
-- return NULL;
--}
--
--/**
-- * relay_switch_subbuf - switch to a new sub-buffer
-- * @buf: channel buffer
-- * @length: size of current event
-- *
-- * Returns either the length passed in or 0 if full.
--
-- * Performs sub-buffer-switch tasks such as invoking callbacks,
-- * updating padding counts, waking up readers, etc.
-- */
--size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
--{
-- void *old, *new;
-- size_t old_subbuf, new_subbuf;
--
-- if (unlikely(length > buf->chan->subbuf_size))
-- goto toobig;
--
-- if (buf->offset != buf->chan->subbuf_size + 1) {
-- buf->prev_padding = buf->chan->subbuf_size - buf->offset;
-- old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
-- buf->padding[old_subbuf] = buf->prev_padding;
-- buf->subbufs_produced++;
-- if (waitqueue_active(&buf->read_wait)) {
-- PREPARE_WORK(&buf->wake_readers, wakeup_readers, buf);
-- schedule_delayed_work(&buf->wake_readers, 1);
-- }
-- }
--
-- old = buf->data;
-- new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
-- new = buf->start + new_subbuf * buf->chan->subbuf_size;
-- buf->offset = 0;
-- if (!buf->chan->cb->subbuf_start(buf, new, old, buf->prev_padding)) {
-- buf->offset = buf->chan->subbuf_size + 1;
-- return 0;
-- }
-- buf->data = new;
-- buf->padding[new_subbuf] = 0;
--
-- if (unlikely(length + buf->offset > buf->chan->subbuf_size))
-- goto toobig;
--
-- return length;
--
--toobig:
-- buf->chan->last_toobig = length;
-- return 0;
--}
--
--/**
-- * relay_subbufs_consumed - update the buffer's sub-buffers-consumed count
-- * @chan: the channel
-- * @cpu: the cpu associated with the channel buffer to update
-- * @subbufs_consumed: number of sub-buffers to add to current buf's count
-- *
-- * Adds to the channel buffer's consumed sub-buffer count.
-- * subbufs_consumed should be the number of sub-buffers newly consumed,
-- * not the total consumed.
-- *
-- * NOTE: kernel clients don't need to call this function if the channel
-- * mode is 'overwrite'.
-- */
--void relay_subbufs_consumed(struct rchan *chan,
-- unsigned int cpu,
-- size_t subbufs_consumed)
--{
-- struct rchan_buf *buf;
--
-- if (!chan)
-- return;
--
-- if (cpu >= NR_CPUS || !chan->buf[cpu])
-- return;
--
-- buf = chan->buf[cpu];
-- buf->subbufs_consumed += subbufs_consumed;
-- if (buf->subbufs_consumed > buf->subbufs_produced)
-- buf->subbufs_consumed = buf->subbufs_produced;
--}
--
--/**
-- * relay_destroy_channel - free the channel struct
-- *
-- * Should only be called from kref_put().
-- */
--void relay_destroy_channel(struct kref *kref)
--{
-- struct rchan *chan = container_of(kref, struct rchan, kref);
-- kfree(chan);
--}
--
--/**
-- * relay_close - close the channel
-- * @chan: the channel
-- *
-- * Closes all channel buffers and frees the channel.
-- */
--void relay_close(struct rchan *chan)
--{
-- unsigned int i;
-- struct rchan_buf *prev = NULL;
--
-- if (!chan)
-- return;
--
-- for (i = 0; i < NR_CPUS; i++) {
-- if (!chan->buf[i] || chan->buf[i] == prev)
-- break;
-- relay_close_buf(chan->buf[i]);
-- prev = chan->buf[i];
-- }
--
-- if (chan->last_toobig)
-- printk(KERN_WARNING "relayfs: one or more items not logged "
-- "[item size (%Zd) > sub-buffer size (%Zd)]\n",
-- chan->last_toobig, chan->subbuf_size);
--
-- kref_put(&chan->kref, relay_destroy_channel);
--}
--
--/**
-- * relay_flush - close the channel
-- * @chan: the channel
-- *
-- * Flushes all channel buffers i.e. forces buffer switch.
-- */
--void relay_flush(struct rchan *chan)
--{
-- unsigned int i;
-- struct rchan_buf *prev = NULL;
--
-- if (!chan)
-- return;
--
-- for (i = 0; i < NR_CPUS; i++) {
-- if (!chan->buf[i] || chan->buf[i] == prev)
-- break;
-- relay_switch_subbuf(chan->buf[i], 0);
-- prev = chan->buf[i];
-- }
--}
--
--EXPORT_SYMBOL_GPL(relay_open);
--EXPORT_SYMBOL_GPL(relay_close);
--EXPORT_SYMBOL_GPL(relay_flush);
--EXPORT_SYMBOL_GPL(relay_reset);
--EXPORT_SYMBOL_GPL(relay_subbufs_consumed);
--EXPORT_SYMBOL_GPL(relay_switch_subbuf);
--EXPORT_SYMBOL_GPL(relay_buf_full);
-diff --git a/fs/relayfs/relay.h b/fs/relayfs/relay.h
-deleted file mode 100644
-index 0993d3e..0000000
---- a/fs/relayfs/relay.h
-+++ /dev/null
-@@ -1,8 +0,0 @@
--#ifndef _RELAY_H
--#define _RELAY_H
--
--extern int relayfs_remove(struct dentry *dentry);
--extern int relay_buf_empty(struct rchan_buf *buf);
--extern void relay_destroy_channel(struct kref *kref);
--
--#endif /* _RELAY_H */
-diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
-index 860e7a4..266ce9d 100644
---- 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 */
-@@ -416,6 +417,8 @@ struct request_queue
- unsigned int sg_reserved_size;
- int node;
-
-+ struct blk_trace *blk_trace;
-+
- /*
- * reserved for flush operations
- */
-diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
-new file mode 100644
-index 0000000..b34d3e7
---- /dev/null
-+++ b/include/linux/blktrace_api.h
-@@ -0,0 +1,277 @@
-+#ifndef BLKTRACE_H
-+#define BLKTRACE_H
-+
-+#include <linux/config.h>
-+#include <linux/blkdev.h>
-+#include <linux/relay.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_NOTIFY = 1 << 10, /* special message */
-+
-+ 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 0x07
-+
-+/*
-+ * 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 device; /* device number */
-+ u32 cpu; /* on what cpu did it happen */
-+ u16 error; /* completion error */
-+ u16 pdu_len; /* length of data after this trace */
-+};
-+
-+/*
-+ * The remap event
-+ */
-+struct blk_io_trace_remap {
-+ u32 device;
-+ u32 __pad;
-+ u64 sector;
-+};
-+
-+enum {
-+ Blktrace_setup = 1,
-+ Blktrace_running,
-+ Blktrace_stopped,
-+};
-+
-+struct blk_trace {
-+ int trace_state;
-+ struct rchan *rchan;
-+ unsigned long *sequence;
-+ u16 act_mask;
-+ u64 start_lba;
-+ u64 end_lba;
-+ u32 pid;
-+ u32 dev;
-+ struct dentry *dir;
-+ struct dentry *dropped_file;
-+ atomic_t dropped;
-+};
-+
-+/*
-+ * User setup structure passed with BLKTRACESTART
-+ */
-+struct blk_user_trace_setup {
-+ char name[BDEVNAME_SIZE]; /* output */
-+ u16 act_mask; /* input */
-+ u32 buf_size; /* input */
-+ u32 buf_nr; /* input */
-+ u64 start_lba;
-+ u64 end_lba;
-+ u32 pid;
-+};
-+
-+#if defined(CONFIG_BLK_DEV_IO_TRACE)
-+extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
-+extern void blk_trace_shutdown(request_queue_t *);
-+extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
-+
-+/**
-+ * blk_add_trace_rq - Add a trace for a request oriented action
-+ * @q: queue the io is for
-+ * @rq: the source request
-+ * @what: the action
-+ *
-+ * Description:
-+ * Records an action against a request. Will log the bio offset + size.
-+ *
-+ **/
-+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);
-+ }
-+}
-+
-+/**
-+ * blk_add_trace_bio - Add a trace for a bio oriented action
-+ * @q: queue the io is for
-+ * @bio: the source bio
-+ * @what: the action
-+ *
-+ * Description:
-+ * Records an action against a bio. Will log the bio offset + size.
-+ *
-+ **/
-+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);
-+}
-+
-+/**
-+ * blk_add_trace_generic - Add a trace for a generic action
-+ * @q: queue the io is for
-+ * @bio: the source bio
-+ * @rw: the data direction
-+ * @what: the action
-+ *
-+ * Description:
-+ * Records a simple trace
-+ *
-+ **/
-+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);
-+}
-+
-+/**
-+ * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
-+ * @q: queue the io is for
-+ * @what: the action
-+ * @bio: the source bio
-+ * @pdu: the integer payload
-+ *
-+ * Description:
-+ * Adds a trace with some integer payload. This might be an unplug
-+ * option given as the action, with the depth at unplug time given
-+ * as the payload
-+ *
-+ **/
-+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);
-+}
-+
-+/**
-+ * blk_add_trace_remap - Add a trace for a remap operation
-+ * @q: queue the io is for
-+ * @bio: the source bio
-+ * @dev: target device
-+ * @from: source sector
-+ * @to: target sector
-+ *
-+ * Description:
-+ * Device mapper or raid target sometimes need to split a bio because
-+ * it spans a stripe (or similar). Add a trace for that action.
-+ *
-+ **/
-+static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
-+ dev_t dev, sector_t from, sector_t to)
-+{
-+ 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(to);
-+
-+ __blk_add_trace(bt, from, 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_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
-+#define blk_trace_shutdown(q) 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, f, t) do {} while (0)
-+#endif /* CONFIG_BLK_DEV_IO_TRACE */
-+
-+#endif
-diff --git a/include/linux/compat_ioctl.h b/include/linux/compat_ioctl.h
-index ae7dfb7..efb518f 100644
---- a/include/linux/compat_ioctl.h
-+++ b/include/linux/compat_ioctl.h
-@@ -97,6 +97,10 @@ COMPATIBLE_IOCTL(BLKRRPART)
- COMPATIBLE_IOCTL(BLKFLSBUF)
- COMPATIBLE_IOCTL(BLKSECTSET)
- COMPATIBLE_IOCTL(BLKSSZGET)
-+COMPATIBLE_IOCTL(BLKTRACESTART)
-+COMPATIBLE_IOCTL(BLKTRACESTOP)
-+COMPATIBLE_IOCTL(BLKTRACESETUP)
-+COMPATIBLE_IOCTL(BLKTRACETEARDOWN)
- ULONG_IOCTL(BLKRASET)
- ULONG_IOCTL(BLKFRASET)
- /* RAID */
-diff --git a/include/linux/fs.h b/include/linux/fs.h
-index 128d008..37da58b 100644
---- a/include/linux/fs.h
-+++ b/include/linux/fs.h
-@@ -197,6 +197,10 @@ 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 BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
-+#define BLKTRACESTART _IO(0x12,116)
-+#define BLKTRACESTOP _IO(0x12,117)
-+#define BLKTRACETEARDOWN _IO(0x12,118)
-
- #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
- #define FIBMAP _IO(0x00,1) /* bmap access */
-diff --git a/include/linux/relay.h b/include/linux/relay.h
-new file mode 100644
-index 0000000..4bcc153
---- /dev/null
-+++ b/include/linux/relay.h
-@@ -0,0 +1,281 @@
-+/*
-+ * linux/include/linux/relay.h
-+ *
-+ * Copyright (C) 2002, 2003 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
-+ * Copyright (C) 1999, 2000, 2001, 2002 - Karim Yaghmour (karim@opersys.com)
-+ *
-+ * CONFIG_RELAY definitions and declarations
-+ */
-+
-+#ifndef _LINUX_RELAY_H
-+#define _LINUX_RELAY_H
-+
-+#include <linux/config.h>
-+#include <linux/types.h>
-+#include <linux/sched.h>
-+#include <linux/wait.h>
-+#include <linux/list.h>
-+#include <linux/fs.h>
-+#include <linux/poll.h>
-+#include <linux/kref.h>
-+
-+/* Needs a _much_ better name... */
-+#define FIX_SIZE(x) ((((x) - 1) & PAGE_MASK) + PAGE_SIZE)
-+
-+/*
-+ * Tracks changes to rchan/rchan_buf structs
-+ */
-+#define RELAYFS_CHANNEL_VERSION 6
-+
-+/*
-+ * Per-cpu relay channel buffer
-+ */
-+struct rchan_buf
-+{
-+ void *start; /* start of channel buffer */
-+ void *data; /* start of current sub-buffer */
-+ size_t offset; /* current offset into sub-buffer */
-+ size_t subbufs_produced; /* count of sub-buffers produced */
-+ size_t subbufs_consumed; /* count of sub-buffers consumed */
-+ struct rchan *chan; /* associated channel */
-+ wait_queue_head_t read_wait; /* reader wait queue */
-+ struct work_struct wake_readers; /* reader wake-up work struct */
-+ struct dentry *dentry; /* channel file dentry */
-+ struct kref kref; /* channel buffer refcount */
-+ struct page **page_array; /* array of current buffer pages */
-+ unsigned int page_count; /* number of current buffer pages */
-+ unsigned int finalized; /* buffer has been finalized */
-+ size_t *padding; /* padding counts per sub-buffer */
-+ size_t prev_padding; /* temporary variable */
-+ size_t bytes_consumed; /* bytes consumed in cur read subbuf */
-+ unsigned int cpu; /* this buf's cpu */
-+} ____cacheline_aligned;
-+
-+/*
-+ * Relay channel data structure
-+ */
-+struct rchan
-+{
-+ u32 version; /* the version of this struct */
-+ size_t subbuf_size; /* sub-buffer size */
-+ size_t n_subbufs; /* number of sub-buffers per buffer */
-+ size_t alloc_size; /* total buffer size allocated */
-+ struct rchan_callbacks *cb; /* client callbacks */
-+ struct kref kref; /* channel refcount */
-+ void *private_data; /* for user-defined data */
-+ size_t last_toobig; /* tried to log event > subbuf size */
-+ struct rchan_buf *buf[NR_CPUS]; /* per-cpu channel buffers */
-+};
-+
-+/*
-+ * Relay channel client callbacks
-+ */
-+struct rchan_callbacks
-+{
-+ /*
-+ * subbuf_start - called on buffer-switch to a new sub-buffer
-+ * @buf: the channel buffer containing the new sub-buffer
-+ * @subbuf: the start of the new sub-buffer
-+ * @prev_subbuf: the start of the previous sub-buffer
-+ * @prev_padding: unused space at the end of previous sub-buffer
-+ *
-+ * The client should return 1 to continue logging, 0 to stop
-+ * logging.
-+ *
-+ * NOTE: subbuf_start will also be invoked when the buffer is
-+ * created, so that the first sub-buffer can be initialized
-+ * if necessary. In this case, prev_subbuf will be NULL.
-+ *
-+ * NOTE: the client can reserve bytes at the beginning of the new
-+ * sub-buffer by calling subbuf_start_reserve() in this callback.
-+ */
-+ int (*subbuf_start) (struct rchan_buf *buf,
-+ void *subbuf,
-+ void *prev_subbuf,
-+ size_t prev_padding);
-+
-+ /*
-+ * buf_mapped - relay buffer mmap notification
-+ * @buf: the channel buffer
-+ * @filp: relay file pointer
-+ *
-+ * Called when a relay file is successfully mmapped
-+ */
-+ void (*buf_mapped)(struct rchan_buf *buf,
-+ struct file *filp);
-+
-+ /*
-+ * buf_unmapped - relay buffer unmap notification
-+ * @buf: the channel buffer
-+ * @filp: relay file pointer
-+ *
-+ * Called when a relay file is successfully unmapped
-+ */
-+ void (*buf_unmapped)(struct rchan_buf *buf,
-+ struct file *filp);
-+ /*
-+ * create_buf_file - create file to represent a relay channel buffer
-+ * @filename: the name of the file to create
-+ * @parent: the parent of the file to create
-+ * @mode: the mode of the file to create
-+ * @buf: the channel buffer
-+ * @is_global: outparam - set non-zero if the buffer should be global
-+ *
-+ * Called during relay_open(), once for each per-cpu buffer,
-+ * to allow the client to create a file to be used to
-+ * represent the corresponding channel buffer. If the file is
-+ * created outside of relay, the parent must also exist in
-+ * that filesystem.
-+ *
-+ * The callback should return the dentry of the file created
-+ * to represent the relay buffer.
-+ *
-+ * Setting the is_global outparam to a non-zero value will
-+ * cause relay_open() to create a single global buffer rather
-+ * than the default set of per-cpu buffers.
-+ *
-+ * See Documentation/filesystems/relayfs.txt for more info.
-+ */
-+ struct dentry *(*create_buf_file)(const char *filename,
-+ struct dentry *parent,
-+ int mode,
-+ struct rchan_buf *buf,
-+ int *is_global);
-+
-+ /*
-+ * remove_buf_file - remove file representing a relay channel buffer
-+ * @dentry: the dentry of the file to remove
-+ *
-+ * Called during relay_close(), once for each per-cpu buffer,
-+ * to allow the client to remove a file used to represent a
-+ * channel buffer.
-+ *
-+ * The callback should return 0 if successful, negative if not.
-+ */
-+ int (*remove_buf_file)(struct dentry *dentry);
-+};
-+
-+/*
-+ * CONFIG_RELAY kernel API, kernel/relay.c
-+ */
-+
-+struct rchan *relay_open(const char *base_filename,
-+ struct dentry *parent,
-+ size_t subbuf_size,
-+ size_t n_subbufs,
-+ struct rchan_callbacks *cb);
-+extern void relay_close(struct rchan *chan);
-+extern void relay_flush(struct rchan *chan);
-+extern void relay_subbufs_consumed(struct rchan *chan,
-+ unsigned int cpu,
-+ size_t consumed);
-+extern void relay_reset(struct rchan *chan);
-+extern int relay_buf_full(struct rchan_buf *buf);
-+
-+extern size_t relay_switch_subbuf(struct rchan_buf *buf,
-+ size_t length);
-+
-+/**
-+ * relay_write - write data into the channel
-+ * @chan: relay channel
-+ * @data: data to be written
-+ * @length: number of bytes to write
-+ *
-+ * Writes data into the current cpu's channel buffer.
-+ *
-+ * Protects the buffer by disabling interrupts. Use this
-+ * if you might be logging from interrupt context. Try
-+ * __relay_write() if you know you won't be logging from
-+ * interrupt context.
-+ */
-+static inline void relay_write(struct rchan *chan,
-+ const void *data,
-+ size_t length)
-+{
-+ unsigned long flags;
-+ struct rchan_buf *buf;
-+
-+ local_irq_save(flags);
-+ buf = chan->buf[smp_processor_id()];
-+ if (unlikely(buf->offset + length > chan->subbuf_size))
-+ length = relay_switch_subbuf(buf, length);
-+ memcpy(buf->data + buf->offset, data, length);
-+ buf->offset += length;
-+ local_irq_restore(flags);
-+}
-+
-+/**
-+ * __relay_write - write data into the channel
-+ * @chan: relay channel
-+ * @data: data to be written
-+ * @length: number of bytes to write
-+ *
-+ * Writes data into the current cpu's channel buffer.
-+ *
-+ * Protects the buffer by disabling preemption. Use
-+ * relay_write() if you might be logging from interrupt
-+ * context.
-+ */
-+static inline void __relay_write(struct rchan *chan,
-+ const void *data,
-+ size_t length)
-+{
-+ struct rchan_buf *buf;
-+
-+ buf = chan->buf[get_cpu()];
-+ if (unlikely(buf->offset + length > buf->chan->subbuf_size))
-+ length = relay_switch_subbuf(buf, length);
-+ memcpy(buf->data + buf->offset, data, length);
-+ buf->offset += length;
-+ put_cpu();
-+}
-+
-+/**
-+ * relay_reserve - reserve slot in channel buffer
-+ * @chan: relay channel
-+ * @length: number of bytes to reserve
-+ *
-+ * Returns pointer to reserved slot, NULL if full.
-+ *
-+ * Reserves a slot in the current cpu's channel buffer.
-+ * Does not protect the buffer at all - caller must provide
-+ * appropriate synchronization.
-+ */
-+static inline void *relay_reserve(struct rchan *chan, size_t length)
-+{
-+ void *reserved;
-+ struct rchan_buf *buf = chan->buf[smp_processor_id()];
-+
-+ if (unlikely(buf->offset + length > buf->chan->subbuf_size)) {
-+ length = relay_switch_subbuf(buf, length);
-+ if (!length)
-+ return NULL;
-+ }
-+ reserved = buf->data + buf->offset;
-+ buf->offset += length;
-+
-+ return reserved;
-+}
-+
-+/**
-+ * subbuf_start_reserve - reserve bytes at the start of a sub-buffer
-+ * @buf: relay channel buffer
-+ * @length: number of bytes to reserve
-+ *
-+ * Helper function used to reserve bytes at the beginning of
-+ * a sub-buffer in the subbuf_start() callback.
-+ */
-+static inline void subbuf_start_reserve(struct rchan_buf *buf,
-+ size_t length)
-+{
-+ BUG_ON(length >= buf->chan->subbuf_size - 1);
-+ buf->offset = length;
-+}
-+
-+/*
-+ * exported relay file operations, kernel/relay.c
-+ */
-+extern struct file_operations relay_file_operations;
-+
-+#endif /* _LINUX_RELAY_H */
-+
-diff --git a/include/linux/sched.h b/include/linux/sched.h
-index 62e6314..e60a91d 100644
---- a/include/linux/sched.h
-+++ b/include/linux/sched.h
-@@ -706,6 +706,7 @@ struct task_struct {
- prio_array_t *array;
-
- unsigned short ioprio;
-+ unsigned int btrace_seq;
-
- unsigned long sleep_avg;
- unsigned long long timestamp, last_ran;
-diff --git a/init/Kconfig b/init/Kconfig
-index 38416a1..fb74fdd 100644
---- a/init/Kconfig
-+++ b/init/Kconfig
-@@ -214,6 +214,17 @@ config CPUSETS
-
- Say N if unsure.
-
-+config RELAY
-+ bool "Kernel->user space relay support (formerly relayfs)"
-+ help
-+ This option enables support for relay interface support in
-+ certain file systems (such as debugfs).
-+ It is designed to provide an efficient mechanism for tools and
-+ facilities to relay large amounts of data from kernel space to
-+ user space.
-+
-+ If unsure, say N.
-+
- source "usr/Kconfig"
-
- config UID16
-diff --git a/kernel/Makefile b/kernel/Makefile
-index 4ae0fbd..aebd7a7 100644
---- a/kernel/Makefile
-+++ b/kernel/Makefile
-@@ -34,6 +34,7 @@ obj-$(CONFIG_DETECT_SOFTLOCKUP) += softl
- obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
- obj-$(CONFIG_SECCOMP) += seccomp.o
- obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
-+obj-$(CONFIG_RELAY) += relay.o
-
- ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
- # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
-diff --git a/kernel/fork.c b/kernel/fork.c
-index ccdfbb1..d35e3ee 100644
---- a/kernel/fork.c
-+++ b/kernel/fork.c
-@@ -181,6 +181,7 @@ static struct task_struct *dup_task_stru
- /* One for us, one for whoever does the "release_task()" (usually parent) */
- atomic_set(&tsk->usage,2);
- atomic_set(&tsk->fs_excl, 0);
-+ tsk->btrace_seq = 0;
- return tsk;
- }
-
-diff --git a/kernel/relay.c b/kernel/relay.c
-new file mode 100644
-index 0000000..c37e29b
---- /dev/null
-+++ b/kernel/relay.c
-@@ -0,0 +1,1011 @@
-+/*
-+ * Public API and common code for kernel->userspace relay file support.
-+ *
-+ * See Documentation/filesystems/relayfs.txt for an overview of relayfs.
-+ *
-+ * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
-+ * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
-+ *
-+ * Moved to kernel/relay.c by Paul Mundt, 2006.
-+ *
-+ * This file is released under the GPL.
-+ */
-+#include <linux/errno.h>
-+#include <linux/stddef.h>
-+#include <linux/slab.h>
-+#include <linux/module.h>
-+#include <linux/string.h>
-+#include <linux/relay.h>
-+#include <linux/vmalloc.h>
-+#include <linux/mm.h>
-+
-+/*
-+ * close() vm_op implementation for relay file mapping.
-+ */
-+static void relay_file_mmap_close(struct vm_area_struct *vma)
-+{
-+ struct rchan_buf *buf = vma->vm_private_data;
-+ buf->chan->cb->buf_unmapped(buf, vma->vm_file);
-+}
-+
-+/*
-+ * nopage() vm_op implementation for relay file mapping.
-+ */
-+static struct page *relay_buf_nopage(struct vm_area_struct *vma,
-+ unsigned long address,
-+ int *type)
-+{
-+ struct page *page;
-+ struct rchan_buf *buf = vma->vm_private_data;
-+ unsigned long offset = address - vma->vm_start;
-+
-+ if (address > vma->vm_end)
-+ return NOPAGE_SIGBUS; /* Disallow mremap */
-+ if (!buf)
-+ return NOPAGE_OOM;
-+
-+ page = vmalloc_to_page(buf->start + offset);
-+ if (!page)
-+ return NOPAGE_OOM;
-+ get_page(page);
-+
-+ if (type)
-+ *type = VM_FAULT_MINOR;
-+
-+ return page;
-+}
-+
-+/*
-+ * vm_ops for relay file mappings.
-+ */
-+static struct vm_operations_struct relay_file_mmap_ops = {
-+ .nopage = relay_buf_nopage,
-+ .close = relay_file_mmap_close,
-+};
-+
-+/**
-+ * relay_mmap_buf: - mmap channel buffer to process address space
-+ * @buf: relay channel buffer
-+ * @vma: vm_area_struct describing memory to be mapped
-+ *
-+ * Returns 0 if ok, negative on error
-+ *
-+ * Caller should already have grabbed mmap_sem.
-+ */
-+int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
-+{
-+ unsigned long length = vma->vm_end - vma->vm_start;
-+ struct file *filp = vma->vm_file;
-+
-+ if (!buf)
-+ return -EBADF;
-+
-+ if (length != (unsigned long)buf->chan->alloc_size)
-+ return -EINVAL;
-+
-+ vma->vm_ops = &relay_file_mmap_ops;
-+ vma->vm_private_data = buf;
-+ buf->chan->cb->buf_mapped(buf, filp);
-+
-+ return 0;
-+}
-+
-+/**
-+ * relay_alloc_buf - allocate a channel buffer
-+ * @buf: the buffer struct
-+ * @size: total size of the buffer
-+ *
-+ * Returns a pointer to the resulting buffer, NULL if unsuccessful. The
-+ * passed in size will get page aligned, if it isn't already.
-+ */
-+static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size)
-+{
-+ void *mem;
-+ unsigned int i, j, n_pages;
-+
-+ *size = PAGE_ALIGN(*size);
-+ n_pages = *size >> PAGE_SHIFT;
-+
-+ buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL);
-+ if (!buf->page_array)
-+ return NULL;
-+
-+ for (i = 0; i < n_pages; i++) {
-+ buf->page_array[i] = alloc_page(GFP_KERNEL);
-+ if (unlikely(!buf->page_array[i]))
-+ goto depopulate;
-+ }
-+ mem = vmap(buf->page_array, n_pages, VM_MAP, PAGE_KERNEL);
-+ if (!mem)
-+ goto depopulate;
-+
-+ memset(mem, 0, *size);
-+ buf->page_count = n_pages;
-+ return mem;
-+
-+depopulate:
-+ for (j = 0; j < i; j++)
-+ __free_page(buf->page_array[j]);
-+ kfree(buf->page_array);
-+ return NULL;
-+}
-+
-+/**
-+ * relay_create_buf - allocate and initialize a channel buffer
-+ * @alloc_size: size of the buffer to allocate
-+ * @n_subbufs: number of sub-buffers in the channel
-+ *
-+ * Returns channel buffer if successful, NULL otherwise
-+ */
-+struct rchan_buf *relay_create_buf(struct rchan *chan)
-+{
-+ struct rchan_buf *buf = kcalloc(1, sizeof(struct rchan_buf), GFP_KERNEL);
-+ if (!buf)
-+ return NULL;
-+
-+ buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL);
-+ if (!buf->padding)
-+ goto free_buf;
-+
-+ buf->start = relay_alloc_buf(buf, &chan->alloc_size);
-+ if (!buf->start)
-+ goto free_buf;
-+
-+ buf->chan = chan;
-+ kref_get(&buf->chan->kref);
-+ return buf;
-+
-+free_buf:
-+ kfree(buf->padding);
-+ kfree(buf);
-+ return NULL;
-+}
-+
-+/**
-+ * relay_destroy_channel - free the channel struct
-+ *
-+ * Should only be called from kref_put().
-+ */
-+void relay_destroy_channel(struct kref *kref)
-+{
-+ struct rchan *chan = container_of(kref, struct rchan, kref);
-+ kfree(chan);
-+}
-+
-+/**
-+ * relay_destroy_buf - destroy an rchan_buf struct and associated buffer
-+ * @buf: the buffer struct
-+ */
-+void relay_destroy_buf(struct rchan_buf *buf)
-+{
-+ struct rchan *chan = buf->chan;
-+ unsigned int i;
-+
-+ if (likely(buf->start)) {
-+ vunmap(buf->start);
-+ for (i = 0; i < buf->page_count; i++)
-+ __free_page(buf->page_array[i]);
-+ kfree(buf->page_array);
-+ }
-+ kfree(buf->padding);
-+ kfree(buf);
-+ kref_put(&chan->kref, relay_destroy_channel);
-+}
-+
-+/**
-+ * relay_remove_buf - remove a channel buffer
-+ *
-+ * Removes the file from the fileystem, which also frees the
-+ * rchan_buf_struct and the channel buffer. Should only be called from
-+ * kref_put().
-+ */
-+void relay_remove_buf(struct kref *kref)
-+{
-+ struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);
-+ buf->chan->cb->remove_buf_file(buf->dentry);
-+ relay_destroy_buf(buf);
-+}
-+
-+/**
-+ * relay_buf_empty - boolean, is the channel buffer empty?
-+ * @buf: channel buffer
-+ *
-+ * Returns 1 if the buffer is empty, 0 otherwise.
-+ */
-+int relay_buf_empty(struct rchan_buf *buf)
-+{
-+ return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1;
-+}
-+EXPORT_SYMBOL_GPL(relay_buf_empty);
-+
-+/**
-+ * relay_buf_full - boolean, is the channel buffer full?
-+ * @buf: channel buffer
-+ *
-+ * Returns 1 if the buffer is full, 0 otherwise.
-+ */
-+int relay_buf_full(struct rchan_buf *buf)
-+{
-+ size_t ready = buf->subbufs_produced - buf->subbufs_consumed;
-+ return (ready >= buf->chan->n_subbufs) ? 1 : 0;
-+}
-+EXPORT_SYMBOL_GPL(relay_buf_full);
-+
-+/*
-+ * High-level relay kernel API and associated functions.
-+ */
-+
-+/*
-+ * rchan_callback implementations defining default channel behavior. Used
-+ * in place of corresponding NULL values in client callback struct.
-+ */
-+
-+/*
-+ * subbuf_start() default callback. Does nothing.
-+ */
-+static int subbuf_start_default_callback (struct rchan_buf *buf,
-+ void *subbuf,
-+ void *prev_subbuf,
-+ size_t prev_padding)
-+{
-+ if (relay_buf_full(buf))
-+ return 0;
-+
-+ return 1;
-+}
-+
-+/*
-+ * buf_mapped() default callback. Does nothing.
-+ */
-+static void buf_mapped_default_callback(struct rchan_buf *buf,
-+ struct file *filp)
-+{
-+}
-+
-+/*
-+ * buf_unmapped() default callback. Does nothing.
-+ */
-+static void buf_unmapped_default_callback(struct rchan_buf *buf,
-+ struct file *filp)
-+{
-+}
-+
-+/*
-+ * create_buf_file_create() default callback. Does nothing.
-+ */
-+static struct dentry *create_buf_file_default_callback(const char *filename,
-+ struct dentry *parent,
-+ int mode,
-+ struct rchan_buf *buf,
-+ int *is_global)
-+{
-+ return NULL;
-+}
-+
-+/*
-+ * remove_buf_file() default callback. Does nothing.
-+ */
-+static int remove_buf_file_default_callback(struct dentry *dentry)
-+{
-+ return -EINVAL;
-+}
-+
-+/* relay channel default callbacks */
-+static struct rchan_callbacks default_channel_callbacks = {
-+ .subbuf_start = subbuf_start_default_callback,
-+ .buf_mapped = buf_mapped_default_callback,
-+ .buf_unmapped = buf_unmapped_default_callback,
-+ .create_buf_file = create_buf_file_default_callback,
-+ .remove_buf_file = remove_buf_file_default_callback,
-+};
-+
-+/**
-+ * wakeup_readers - wake up readers waiting on a channel
-+ * @private: the channel buffer
-+ *
-+ * This is the work function used to defer reader waking. The
-+ * reason waking is deferred is that calling directly from write
-+ * causes problems if you're writing from say the scheduler.
-+ */
-+static void wakeup_readers(void *private)
-+{
-+ struct rchan_buf *buf = private;
-+ wake_up_interruptible(&buf->read_wait);
-+}
-+
-+/**
-+ * __relay_reset - reset a channel buffer
-+ * @buf: the channel buffer
-+ * @init: 1 if this is a first-time initialization
-+ *
-+ * See relay_reset for description of effect.
-+ */
-+static inline void __relay_reset(struct rchan_buf *buf, unsigned int init)
-+{
-+ size_t i;
-+
-+ if (init) {
-+ init_waitqueue_head(&buf->read_wait);
-+ kref_init(&buf->kref);
-+ INIT_WORK(&buf->wake_readers, NULL, NULL);
-+ } else {
-+ cancel_delayed_work(&buf->wake_readers);
-+ flush_scheduled_work();
-+ }
-+
-+ buf->subbufs_produced = 0;
-+ buf->subbufs_consumed = 0;
-+ buf->bytes_consumed = 0;
-+ buf->finalized = 0;
-+ buf->data = buf->start;
-+ buf->offset = 0;
-+
-+ for (i = 0; i < buf->chan->n_subbufs; i++)
-+ buf->padding[i] = 0;
-+
-+ buf->chan->cb->subbuf_start(buf, buf->data, NULL, 0);
-+}
-+
-+/**
-+ * relay_reset - reset the channel
-+ * @chan: the channel
-+ *
-+ * This has the effect of erasing all data from all channel buffers
-+ * and restarting the channel in its initial state. The buffers
-+ * are not freed, so any mappings are still in effect.
-+ *
-+ * NOTE: Care should be taken that the channel isn't actually
-+ * being used by anything when this call is made.
-+ */
-+void relay_reset(struct rchan *chan)
-+{
-+ unsigned int i;
-+ struct rchan_buf *prev = NULL;
-+
-+ if (!chan)
-+ return;
-+
-+ for (i = 0; i < NR_CPUS; i++) {
-+ if (!chan->buf[i] || chan->buf[i] == prev)
-+ break;
-+ __relay_reset(chan->buf[i], 0);
-+ prev = chan->buf[i];
-+ }
-+}
-+EXPORT_SYMBOL_GPL(relay_reset);
-+
-+/**
-+ * relay_open_buf - create a new relay channel buffer
-+ *
-+ * Internal - used by relay_open().
-+ */
-+static struct rchan_buf *relay_open_buf(struct rchan *chan,
-+ const char *filename,
-+ struct dentry *parent,
-+ int *is_global)
-+{
-+ struct rchan_buf *buf;
-+ struct dentry *dentry;
-+
-+ if (*is_global)
-+ return chan->buf[0];
-+
-+ buf = relay_create_buf(chan);
-+ if (!buf)
-+ return NULL;
-+
-+ /* Create file in fs */
-+ dentry = chan->cb->create_buf_file(filename, parent, S_IRUSR,
-+ buf, is_global);
-+ if (!dentry) {
-+ relay_destroy_buf(buf);
-+ return NULL;
-+ }
-+
-+ buf->dentry = dentry;
-+ __relay_reset(buf, 1);
-+
-+ return buf;
-+}
-+
-+/**
-+ * relay_close_buf - close a channel buffer
-+ * @buf: channel buffer
-+ *
-+ * Marks the buffer finalized and restores the default callbacks.
-+ * The channel buffer and channel buffer data structure are then freed
-+ * automatically when the last reference is given up.
-+ */
-+static inline void relay_close_buf(struct rchan_buf *buf)
-+{
-+ buf->finalized = 1;
-+ cancel_delayed_work(&buf->wake_readers);
-+ flush_scheduled_work();
-+ kref_put(&buf->kref, relay_remove_buf);
-+}
-+
-+static inline void setup_callbacks(struct rchan *chan,
-+ struct rchan_callbacks *cb)
-+{
-+ if (!cb) {
-+ chan->cb = &default_channel_callbacks;
-+ return;
-+ }
-+
-+ if (!cb->subbuf_start)
-+ cb->subbuf_start = subbuf_start_default_callback;
-+ if (!cb->buf_mapped)
-+ cb->buf_mapped = buf_mapped_default_callback;
-+ if (!cb->buf_unmapped)
-+ cb->buf_unmapped = buf_unmapped_default_callback;
-+ if (!cb->create_buf_file)
-+ cb->create_buf_file = create_buf_file_default_callback;
-+ if (!cb->remove_buf_file)
-+ cb->remove_buf_file = remove_buf_file_default_callback;
-+ chan->cb = cb;
-+}
-+
-+/**
-+ * relay_open - create a new relay channel
-+ * @base_filename: base name of files to create
-+ * @parent: dentry of parent directory, NULL for root directory
-+ * @subbuf_size: size of sub-buffers
-+ * @n_subbufs: number of sub-buffers
-+ * @cb: client callback functions
-+ *
-+ * Returns channel pointer if successful, NULL otherwise.
-+ *
-+ * Creates a channel buffer for each cpu using the sizes and
-+ * attributes specified. The created channel buffer files
-+ * will be named base_filename0...base_filenameN-1. File
-+ * permissions will be S_IRUSR.
-+ */
-+struct rchan *relay_open(const char *base_filename,
-+ struct dentry *parent,
-+ size_t subbuf_size,
-+ size_t n_subbufs,
-+ struct rchan_callbacks *cb)
-+{
-+ unsigned int i;
-+ struct rchan *chan;
-+ char *tmpname;
-+ int is_global = 0;
-+
-+ if (!base_filename)
-+ return NULL;
-+
-+ if (!(subbuf_size && n_subbufs))
-+ return NULL;
-+
-+ chan = kcalloc(1, sizeof(struct rchan), GFP_KERNEL);
-+ if (!chan)
-+ return NULL;
-+
-+ chan->version = RELAYFS_CHANNEL_VERSION;
-+ chan->n_subbufs = n_subbufs;
-+ chan->subbuf_size = subbuf_size;
-+ chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs);
-+ setup_callbacks(chan, cb);
-+ kref_init(&chan->kref);
-+
-+ tmpname = kmalloc(NAME_MAX + 1, GFP_KERNEL);
-+ if (!tmpname)
-+ goto free_chan;
-+
-+ for_each_online_cpu(i) {
-+ sprintf(tmpname, "%s%d", base_filename, i);
-+ chan->buf[i] = relay_open_buf(chan, tmpname, parent,
-+ &is_global);
-+ chan->buf[i]->cpu = i;
-+ if (!chan->buf[i])
-+ goto free_bufs;
-+ }
-+
-+ kfree(tmpname);
-+ return chan;
-+
-+free_bufs:
-+ for (i = 0; i < NR_CPUS; i++) {
-+ if (!chan->buf[i])
-+ break;
-+ relay_close_buf(chan->buf[i]);
-+ if (is_global)
-+ break;
-+ }
-+ kfree(tmpname);
-+
-+free_chan:
-+ kref_put(&chan->kref, relay_destroy_channel);
-+ return NULL;
-+}
-+EXPORT_SYMBOL_GPL(relay_open);
-+
-+/**
-+ * relay_switch_subbuf - switch to a new sub-buffer
-+ * @buf: channel buffer
-+ * @length: size of current event
-+ *
-+ * Returns either the length passed in or 0 if full.
-+ *
-+ * Performs sub-buffer-switch tasks such as invoking callbacks,
-+ * updating padding counts, waking up readers, etc.
-+ */
-+size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
-+{
-+ void *old, *new;
-+ size_t old_subbuf, new_subbuf;
-+
-+ if (unlikely(length > buf->chan->subbuf_size))
-+ goto toobig;
-+
-+ if (buf->offset != buf->chan->subbuf_size + 1) {
-+ buf->prev_padding = buf->chan->subbuf_size - buf->offset;
-+ old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
-+ buf->padding[old_subbuf] = buf->prev_padding;
-+ buf->subbufs_produced++;
-+ buf->dentry->d_inode->i_size += buf->chan->subbuf_size -
-+ buf->padding[old_subbuf];
-+ smp_mb();
-+ if (waitqueue_active(&buf->read_wait)) {
-+ PREPARE_WORK(&buf->wake_readers, wakeup_readers, buf);
-+ schedule_delayed_work(&buf->wake_readers, 1);
-+ }
-+ }
-+
-+ old = buf->data;
-+ new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
-+ new = buf->start + new_subbuf * buf->chan->subbuf_size;
-+ buf->offset = 0;
-+ if (!buf->chan->cb->subbuf_start(buf, new, old, buf->prev_padding)) {
-+ buf->offset = buf->chan->subbuf_size + 1;
-+ return 0;
-+ }
-+ buf->data = new;
-+ buf->padding[new_subbuf] = 0;
-+
-+ if (unlikely(length + buf->offset > buf->chan->subbuf_size))
-+ goto toobig;
-+
-+ return length;
-+
-+toobig:
-+ buf->chan->last_toobig = length;
-+ return 0;
-+}
-+EXPORT_SYMBOL_GPL(relay_switch_subbuf);
-+
-+/**
-+ * relay_subbufs_consumed - update the buffer's sub-buffers-consumed count
-+ * @chan: the channel
-+ * @cpu: the cpu associated with the channel buffer to update
-+ * @subbufs_consumed: number of sub-buffers to add to current buf's count
-+ *
-+ * Adds to the channel buffer's consumed sub-buffer count.
-+ * subbufs_consumed should be the number of sub-buffers newly consumed,
-+ * not the total consumed.
-+ *
-+ * NOTE: kernel clients don't need to call this function if the channel
-+ * mode is 'overwrite'.
-+ */
-+void relay_subbufs_consumed(struct rchan *chan,
-+ unsigned int cpu,
-+ size_t subbufs_consumed)
-+{
-+ struct rchan_buf *buf;
-+
-+ if (!chan)
-+ return;
-+
-+ if (cpu >= NR_CPUS || !chan->buf[cpu])
-+ return;
-+
-+ buf = chan->buf[cpu];
-+ buf->subbufs_consumed += subbufs_consumed;
-+ if (buf->subbufs_consumed > buf->subbufs_produced)
-+ buf->subbufs_consumed = buf->subbufs_produced;
-+}
-+EXPORT_SYMBOL_GPL(relay_subbufs_consumed);
-+
-+/**
-+ * relay_close - close the channel
-+ * @chan: the channel
-+ *
-+ * Closes all channel buffers and frees the channel.
-+ */
-+void relay_close(struct rchan *chan)
-+{
-+ unsigned int i;
-+ struct rchan_buf *prev = NULL;
-+
-+ if (!chan)
-+ return;
-+
-+ for (i = 0; i < NR_CPUS; i++) {
-+ if (!chan->buf[i] || chan->buf[i] == prev)
-+ break;
-+ relay_close_buf(chan->buf[i]);
-+ prev = chan->buf[i];
-+ }
-+
-+ if (chan->last_toobig)
-+ printk(KERN_WARNING "relay: one or more items not logged "
-+ "[item size (%Zd) > sub-buffer size (%Zd)]\n",
-+ chan->last_toobig, chan->subbuf_size);
-+
-+ kref_put(&chan->kref, relay_destroy_channel);
-+}
-+EXPORT_SYMBOL_GPL(relay_close);
-+
-+/**
-+ * relay_flush - close the channel
-+ * @chan: the channel
-+ *
-+ * Flushes all channel buffers i.e. forces buffer switch.
-+ */
-+void relay_flush(struct rchan *chan)
-+{
-+ unsigned int i;
-+ struct rchan_buf *prev = NULL;
-+
-+ if (!chan)
-+ return;
-+
-+ for (i = 0; i < NR_CPUS; i++) {
-+ if (!chan->buf[i] || chan->buf[i] == prev)
-+ break;
-+ relay_switch_subbuf(chan->buf[i], 0);
-+ prev = chan->buf[i];
-+ }
-+}
-+EXPORT_SYMBOL_GPL(relay_flush);
-+
-+/**
-+ * relay_file_open - open file op for relay files
-+ * @inode: the inode
-+ * @filp: the file
-+ *
-+ * Increments the channel buffer refcount.
-+ */
-+static int relay_file_open(struct inode *inode, struct file *filp)
-+{
-+ struct rchan_buf *buf = inode->u.generic_ip;
-+ kref_get(&buf->kref);
-+ filp->private_data = buf;
-+
-+ return 0;
-+}
-+
-+/**
-+ * relay_file_mmap - mmap file op for relay files
-+ * @filp: the file
-+ * @vma: the vma describing what to map
-+ *
-+ * Calls upon relay_mmap_buf to map the file into user space.
-+ */
-+static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma)
-+{
-+ struct rchan_buf *buf = filp->private_data;
-+ return relay_mmap_buf(buf, vma);
-+}
-+
-+/**
-+ * relay_file_poll - poll file op for relay files
-+ * @filp: the file
-+ * @wait: poll table
-+ *
-+ * Poll implemention.
-+ */
-+static unsigned int relay_file_poll(struct file *filp, poll_table *wait)
-+{
-+ unsigned int mask = 0;
-+ struct rchan_buf *buf = filp->private_data;
-+
-+ if (buf->finalized)
-+ return POLLERR;
-+
-+ if (filp->f_mode & FMODE_READ) {
-+ poll_wait(filp, &buf->read_wait, wait);
-+ if (!relay_buf_empty(buf))
-+ mask |= POLLIN | POLLRDNORM;
-+ }
-+
-+ return mask;
-+}
-+
-+/**
-+ * relay_file_release - release file op for relay files
-+ * @inode: the inode
-+ * @filp: the file
-+ *
-+ * Decrements the channel refcount, as the filesystem is
-+ * no longer using it.
-+ */
-+static int relay_file_release(struct inode *inode, struct file *filp)
-+{
-+ struct rchan_buf *buf = filp->private_data;
-+ kref_put(&buf->kref, relay_remove_buf);
-+
-+ return 0;
-+}
-+
-+/**
-+ * relay_file_read_consume - update the consumed count for the buffer
-+ */
-+static void relay_file_read_consume(struct rchan_buf *buf,
-+ size_t read_pos,
-+ size_t bytes_consumed)
-+{
-+ size_t subbuf_size = buf->chan->subbuf_size;
-+ size_t n_subbufs = buf->chan->n_subbufs;
-+ size_t read_subbuf;
-+
-+ if (buf->bytes_consumed + bytes_consumed > subbuf_size) {
-+ relay_subbufs_consumed(buf->chan, buf->cpu, 1);
-+ buf->bytes_consumed = 0;
-+ }
-+
-+ buf->bytes_consumed += bytes_consumed;
-+ read_subbuf = read_pos / buf->chan->subbuf_size;
-+ if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) {
-+ if ((read_subbuf == buf->subbufs_produced % n_subbufs) &&
-+ (buf->offset == subbuf_size))
-+ return;
-+ relay_subbufs_consumed(buf->chan, buf->cpu, 1);
-+ buf->bytes_consumed = 0;
-+ }
-+}
-+
-+/**
-+ * relay_file_read_avail - boolean, are there unconsumed bytes available?
-+ */
-+static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
-+{
-+ size_t subbuf_size = buf->chan->subbuf_size;
-+ size_t n_subbufs = buf->chan->n_subbufs;
-+ size_t produced = buf->subbufs_produced;
-+ size_t consumed = buf->subbufs_consumed;
-+
-+ relay_file_read_consume(buf, read_pos, 0);
-+
-+ if (unlikely(buf->offset > subbuf_size)) {
-+ if (produced == consumed)
-+ return 0;
-+ return 1;
-+ }
-+
-+ if (unlikely(produced - consumed >= n_subbufs)) {
-+ consumed = (produced / n_subbufs) * n_subbufs;
-+ buf->subbufs_consumed = consumed;
-+ }
-+
-+ produced = (produced % n_subbufs) * subbuf_size + buf->offset;
-+ consumed = (consumed % n_subbufs) * subbuf_size + buf->bytes_consumed;
-+
-+ if (consumed > produced)
-+ produced += n_subbufs * subbuf_size;
-+
-+ if (consumed == produced)
-+ return 0;
-+
-+ return 1;
-+}
-+
-+/**
-+ * relay_file_read_subbuf_avail - return bytes available in sub-buffer
-+ */
-+static size_t relay_file_read_subbuf_avail(size_t read_pos,
-+ struct rchan_buf *buf)
-+{
-+ size_t padding, avail = 0;
-+ size_t read_subbuf, read_offset, write_subbuf, write_offset;
-+ size_t subbuf_size = buf->chan->subbuf_size;
-+
-+ write_subbuf = (buf->data - buf->start) / subbuf_size;
-+ write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
-+ read_subbuf = read_pos / subbuf_size;
-+ read_offset = read_pos % subbuf_size;
-+ padding = buf->padding[read_subbuf];
-+
-+ if (read_subbuf == write_subbuf) {
-+ if (read_offset + padding < write_offset)
-+ avail = write_offset - (read_offset + padding);
-+ } else
-+ avail = (subbuf_size - padding) - read_offset;
-+
-+ return avail;
-+}
-+
-+/**
-+ * relay_file_read_start_pos - find the first available byte to read
-+ *
-+ * If the read_pos is in the middle of padding, return the
-+ * position of the first actually available byte, otherwise
-+ * return the original value.
-+ */
-+static size_t relay_file_read_start_pos(size_t read_pos,
-+ struct rchan_buf *buf)
-+{
-+ size_t read_subbuf, padding, padding_start, padding_end;
-+ size_t subbuf_size = buf->chan->subbuf_size;
-+ size_t n_subbufs = buf->chan->n_subbufs;
-+
-+ read_subbuf = read_pos / subbuf_size;
-+ padding = buf->padding[read_subbuf];
-+ padding_start = (read_subbuf + 1) * subbuf_size - padding;
-+ padding_end = (read_subbuf + 1) * subbuf_size;
-+ if (read_pos >= padding_start && read_pos < padding_end) {
-+ read_subbuf = (read_subbuf + 1) % n_subbufs;
-+ read_pos = read_subbuf * subbuf_size;
-+ }
-+
-+ return read_pos;
-+}
-+
-+/**
-+ * relay_file_read_end_pos - return the new read position
-+ */
-+static size_t relay_file_read_end_pos(struct rchan_buf *buf,
-+ size_t read_pos,
-+ size_t count)
-+{
-+ size_t read_subbuf, padding, end_pos;
-+ size_t subbuf_size = buf->chan->subbuf_size;
-+ size_t n_subbufs = buf->chan->n_subbufs;
-+
-+ read_subbuf = read_pos / subbuf_size;
-+ padding = buf->padding[read_subbuf];
-+ if (read_pos % subbuf_size + count + padding == subbuf_size)
-+ end_pos = (read_subbuf + 1) * subbuf_size;
-+ else
-+ end_pos = read_pos + count;
-+ if (end_pos >= subbuf_size * n_subbufs)
-+ end_pos = 0;
-+
-+ return end_pos;
-+}
-+
-+/**
-+ * subbuf_read_actor - read up to one subbuf's worth of data
-+ */
-+static int subbuf_read_actor(size_t read_start,
-+ struct rchan_buf *buf,
-+ size_t avail,
-+ read_descriptor_t *desc,
-+ read_actor_t actor)
-+{
-+ void *from;
-+ int ret = 0;
-+
-+ from = buf->start + read_start;
-+ ret = avail;
-+ if (copy_to_user(desc->arg.data, from, avail)) {
-+ desc->error = -EFAULT;
-+ ret = 0;
-+ }
-+ desc->arg.data += ret;
-+ desc->written += ret;
-+ desc->count -= ret;
-+
-+ return ret;
-+}
-+
-+/**
-+ * subbuf_send_actor - send up to one subbuf's worth of data
-+ */
-+static int subbuf_send_actor(size_t read_start,
-+ struct rchan_buf *buf,
-+ size_t avail,
-+ read_descriptor_t *desc,
-+ read_actor_t actor)
-+{
-+ unsigned long pidx, poff;
-+ unsigned int subbuf_pages;
-+ int ret = 0;
-+
-+ subbuf_pages = buf->chan->alloc_size >> PAGE_SHIFT;
-+ pidx = (read_start / PAGE_SIZE) % subbuf_pages;
-+ poff = read_start & ~PAGE_MASK;
-+ while (avail) {
-+ struct page *p = buf->page_array[pidx];
-+ unsigned int len;
-+
-+ len = PAGE_SIZE - poff;
-+ if (len > avail)
-+ len = avail;
-+
-+ len = actor(desc, p, poff, len);
-+ if (desc->error)
-+ break;
-+
-+ avail -= len;
-+ ret += len;
-+ poff = 0;
-+ pidx = (pidx + 1) % subbuf_pages;
-+ }
-+
-+ return ret;
-+}
-+
-+typedef int (*subbuf_actor_t) (size_t read_start,
-+ struct rchan_buf *buf,
-+ size_t avail,
-+ read_descriptor_t *desc,
-+ read_actor_t actor);
-+
-+/**
-+ * relay_file_read_subbufs - read count bytes, bridging subbuf boundaries
-+ */
-+static inline ssize_t relay_file_read_subbufs(struct file *filp,
-+ loff_t *ppos,
-+ size_t count,
-+ subbuf_actor_t subbuf_actor,
-+ read_actor_t actor,
-+ void *target)
-+{
-+ struct rchan_buf *buf = filp->private_data;
-+ size_t read_start, avail;
-+ read_descriptor_t desc;
-+ int ret;
-+
-+ if (!count)
-+ return 0;
-+
-+ desc.written = 0;
-+ desc.count = count;
-+ desc.arg.data = target;
-+ desc.error = 0;
-+
-+ mutex_lock(&filp->f_dentry->d_inode->i_mutex);
-+ do {
-+ if (!relay_file_read_avail(buf, *ppos))
-+ break;
-+
-+ read_start = relay_file_read_start_pos(*ppos, buf);
-+ avail = relay_file_read_subbuf_avail(read_start, buf);
-+ if (!avail)
-+ break;
-+
-+ avail = min(desc.count, avail);
-+ ret = subbuf_actor(read_start, buf, avail, &desc, actor);
-+ if (desc.error < 0)
-+ break;
-+
-+ if (ret) {
-+ relay_file_read_consume(buf, read_start, ret);
-+ *ppos = relay_file_read_end_pos(buf, read_start, ret);
-+ }
-+ } while (desc.count && ret);
-+ mutex_unlock(&filp->f_dentry->d_inode->i_mutex);
-+
-+ return desc.written;
-+}
-+
-+static ssize_t relay_file_read(struct file *filp,
-+ char __user *buffer,
-+ size_t count,
-+ loff_t *ppos)
-+{
-+ return relay_file_read_subbufs(filp, ppos, count, subbuf_read_actor,
-+ NULL, buffer);
-+}
-+
-+static ssize_t relay_file_sendfile(struct file *filp,
-+ loff_t *ppos,
-+ size_t count,
-+ read_actor_t actor,
-+ void *target)
-+{
-+ return relay_file_read_subbufs(filp, ppos, count, subbuf_send_actor,
-+ actor, target);
-+}
-+
-+struct file_operations relay_file_operations = {
-+ .open = relay_file_open,
-+ .poll = relay_file_poll,
-+ .mmap = relay_file_mmap,
-+ .read = relay_file_read,
-+ .llseek = no_llseek,
-+ .release = relay_file_release,
-+ .sendfile = relay_file_sendfile,
-+};
-+EXPORT_SYMBOL_GPL(relay_file_operations);
-diff --git a/mm/highmem.c b/mm/highmem.c
-index ce2e7e8..d0ea1ee 100644
---- 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_api.h>
- #include <asm/tlbflush.h>
-
- static mempool_t *page_pool, *isa_page_pool;
-@@ -483,6 +484,8 @@ void blk_queue_bounce(request_queue_t *q
- pool = isa_page_pool;
- }
-
-+ blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
-+
- /*
- * slow path
- */
projects / blktrace.git / commitdiff