Merge branch 'blktrace' of git://brick.kernel.dk/data/git/linux-2.6-block
authorLinus Torvalds <torvalds@g5.osdl.org>
Fri, 24 Mar 2006 00:24:24 +0000 (16:24 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Fri, 24 Mar 2006 00:24:24 +0000 (16:24 -0800)
* 'blktrace' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] Block queue IO tracing support (blktrace) as of 2006-03-23
  [PATCH] relay: consolidate sendfile() and read() code
  [PATCH] relay: add sendfile() support
  [PATCH] relay: migrate from relayfs to a generic relay API

29 files changed:
block/Kconfig
block/Makefile
block/blktrace.c [new file with mode: 0644]
block/elevator.c
block/ioctl.c
block/ll_rw_blk.c
drivers/block/cciss.c
drivers/md/dm.c
fs/Kconfig
fs/Makefile
fs/bio.c
fs/compat_ioctl.c
fs/relayfs/Makefile [deleted file]
fs/relayfs/buffers.c [deleted file]
fs/relayfs/buffers.h [deleted file]
fs/relayfs/inode.c [deleted file]
fs/relayfs/relay.c [deleted file]
fs/relayfs/relay.h [deleted file]
include/linux/blkdev.h
include/linux/blktrace_api.h [new file with mode: 0644]
include/linux/compat_ioctl.h
include/linux/fs.h
include/linux/relay.h [new file with mode: 0644]
include/linux/sched.h
init/Kconfig
kernel/Makefile
kernel/fork.c
kernel/relay.c [new file with mode: 0644]
mm/highmem.c

index 377f6dd20e1799afe57f9881e3cd8ac222697f8e..96783645092dc106cd4f4b300958aeae5b684e2a 100644 (file)
@@ -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
index 7e4f93e2b44e9a87503a90bce18c246245cd040a..c05de0e0037fe6f14f9e6f508bece1271568bb36 100644 (file)
@@ -8,3 +8,5 @@ obj-$(CONFIG_IOSCHED_NOOP)      += noop-iosched.o
 obj-$(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 (file)
index 0000000..36f3a17
--- /dev/null
@@ -0,0 +1,538 @@
+/*
+ * 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);
+       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;
+
+       mutex_lock(&bdev->bd_mutex);
+
+       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;
+       }
+
+       mutex_unlock(&bdev->bd_mutex);
+       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);
+
index db3d0d8296a05c908f5dd38100593217c8c7d114..5e558c4689a4f561117cf89b5c4867d045699ad8 100644 (file)
@@ -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>
 
@@ -333,6 +334,8 @@ void elv_insert(request_queue_t *q, struct request *rq, int where)
        struct list_head *pos;
        unsigned ordseq;
 
+       blk_add_trace_rq(q, rq, BLK_TA_INSERT);
+
        rq->q = q;
 
        switch (where) {
@@ -499,6 +502,7 @@ struct request *elv_next_request(request_queue_t *q)
                         * 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) {
index 35fdb7dc6512028be4a3d7e1e4012aaadf1b4ddf..9cfa2e1ecb24c2568e020222026271f68631deb7 100644 (file)
@@ -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 file *file, struct block_device *bdev,
                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;
 }
index 6c793b196aa918da946d7378667f8a08dd7c4005..062067fa7ead0340ee3f5da91f82af80ec097e82 100644 (file)
@@ -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(struct backing_dev_info *bdi,
        /*
         * 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 long data)
 {
        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);
 }
 
@@ -1753,6 +1766,9 @@ static void blk_release_queue(struct kobject *kobj)
        if (q->queue_tags)
                __blk_queue_free_tags(q);
 
+       if (q->blk_trace)
+               blk_trace_shutdown(q);
+
        kmem_cache_free(requestq_cachep, q);
 }
 
@@ -2129,6 +2145,8 @@ rq_starved:
        
        rq_init(q, rq);
        rq->rl = rl;
+
+       blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
 out:
        return rq;
 }
@@ -2157,6 +2175,8 @@ static struct request *get_request_wait(request_queue_t *q, int rw,
                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();
@@ -2210,6 +2230,8 @@ 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);
 
@@ -2844,6 +2866,8 @@ static int __make_request(request_queue_t *q, struct bio *bio)
                        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;
@@ -2859,6 +2883,8 @@ static int __make_request(request_queue_t *q, struct bio *bio)
                        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;
 
@@ -2976,6 +3002,7 @@ void generic_make_request(struct bio *bio)
        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. */
@@ -3002,6 +3029,8 @@ void generic_make_request(struct bio *bio)
         * 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];
 
@@ -3034,6 +3063,15 @@ 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);
 }
@@ -3153,6 +3191,8 @@ static int __end_that_request_first(struct request *req, int uptodate,
        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
         */
index e29b8926f80ed08e1c618e236c8186720f0f1ea9..1f2890989b56086f7b175475bfb2cf3a6a6d48c8 100644 (file)
@@ -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( ctlr_info_t *h, CommandList_struct *cmd,
 
        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);
 }
 
index 26b08ee425c74d6b0ce9ecee09a5d817a1e51841..8c82373f7ff31f24b8c0439e17c00d5a8873f30d 100644 (file)
@@ -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, int error)
                        /* 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 *ti, struct bio *clone,
                      struct target_io *tio)
 {
        int r;
+       sector_t sector;
 
        /*
         * Sanity checks.
@@ -407,10 +411,17 @@ static void __map_bio(struct dm_target *ti, struct bio *clone,
         * 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 */
index e9749b0eecd8a27e5a1d09ece2eee57e63c14529..c8d0a209120cbcb0819afe2b35b91cba4174537b 100644 (file)
@@ -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
index 1db711319c80f5fe260c5459ac66a1a035439da5..080b3867be4dc154aaec7f0eb898eb84ddf9032c 100644 (file)
@@ -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/
index 8f1d2e815c96b696a630ba154ae9c438e3fa3fb2..0a8c59cb68f527fd98152d12a10ef1eb2e7f049c 100644 (file)
--- 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 *bi, mempool_t *pool, int first_sectors)
        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);
index c666769a875d2fc0e80927caf6db038b036bc42b..7c031f00fd798ede5c3edf885c7d8a6fef51250b 100644 (file)
@@ -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 (file)
index e76e182..0000000
+++ /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 (file)
index 1018781..0000000
+++ /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 (file)
index 37a1249..0000000
+++ /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 (file)
index 3835230..0000000
+++ /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 (file)
index abf3cea..0000000
+++ /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 (file)
index 0993d3e..0000000
+++ /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 */
index 56bb6a4e15f3b2afe80bb4dee0026f6fc1518852..c179966f1a2fea92faa912ffbf8133478ee9b30d 100644 (file)
@@ -22,6 +22,7 @@ typedef struct request_queue request_queue_t;
 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 (file)
index 0000000..b34d3e7
--- /dev/null
@@ -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
index ae7dfb790df3b5ebcd2c1e5e0f695c31553c306d..efb518f16bb3a52cd01387de1f487c5ef5aff850 100644 (file)
@@ -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 */
index f9c9dea636d0ba7be7637c6f1975c669052c58ab..9b34a1b034550738d7cba54c5766401cbf237c1d 100644 (file)
@@ -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 (file)
index 0000000..4bcc153
--- /dev/null
@@ -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 */
+
index 62e6314382f091826490f80ef6c839d9587c8694..e60a91d5b36929560fd34895039eca315c166bd3 100644 (file)
@@ -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;
index 38416a199def24332f22692e9da1203a962a8d58..1d19fd25204bc2083a002e73c9240b20e95345e4 100644 (file)
@@ -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
index 4ae0fbde815df537c8f1833ff94fccf91269a7ac..aebd7a78984e8aa2e82b95579d33f8c754d9586d 100644 (file)
@@ -34,6 +34,7 @@ obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
 obj-$(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
index c79ae0b19a4922da1ff651f802eb199afe4fe7c0..c21bae8c93b94bd8cfe60129af508a64ddb67c33 100644 (file)
@@ -181,6 +181,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
        /* 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 (file)
index 0000000..33345e7
--- /dev/null
@@ -0,0 +1,1012 @@
+/*
+ * 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);
+               if (!chan->buf[i])
+                       goto free_bufs;
+
+               chan->buf[i]->cpu = i;
+       }
+
+       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);
index ce2e7e8bbfa7102a78473d1a47c24a41f7788b83..d0ea1eec6a9a023415e3621e0332cdd837130ca3 100644 (file)
@@ -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, struct bio **bio_orig)
                pool = isa_page_pool;
        }
 
+       blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
+
        /*
         * slow path
         */