block: replace bd_mutex with a per-gendisk mutex

bd_mutex is primarily used for synchronizing the block device open and
release path, which recurses from partitions to the whole disk device.
The fact that we have two locks makes life unnecessarily complex due
to lock order constrains.  Replace the two levels of locking with a
single mutex in the gendisk structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/block/genhd.c b/block/genhd.c
index 7832968ce3fbb793048d0c2b69671ce8bfe4fc25..999f7142b04e7d7cfeecbde452bed5e37b3e70a9 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1350,7 +1350,7 @@ static const struct attribute_group *disk_attr_groups[] = {
  * original ptbl is freed using RCU callback.
  *
  * LOCKING:
- * Matching bd_mutex locked or the caller is the only user of @disk.
+ * disk->mutex locked or the caller is the only user of @disk.
  */
 static void disk_replace_part_tbl(struct gendisk *disk,
                                  struct disk_part_tbl *new_ptbl)
@@ -1375,7 +1375,7 @@ static void disk_replace_part_tbl(struct gendisk *disk,
  * uses RCU to allow unlocked dereferencing for stats and other stuff.
  *
  * LOCKING:
- * Matching bd_mutex locked or the caller is the only user of @disk.
+ * disk->mutex locked or the caller is the only user of @disk.
  * Might sleep.
  *
  * RETURNS:
@@ -1616,6 +1616,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
        if (!disk->part0.dkstats)
                goto out_bdput;
 
+       mutex_init(&disk->mutex);
        init_rwsem(&disk->lookup_sem);
        disk->node_id = node_id;
        if (disk_expand_part_tbl(disk, 0)) {
@@ -1842,7 +1843,7 @@ void disk_unblock_events(struct gendisk *disk)
  * doesn't clear the events from @disk->ev.
  *
  * CONTEXT:
- * If @mask is non-zero must be called with bdev->bd_mutex held.
+ * If @mask is non-zero must be called with disk->mutex held.
  */
 void disk_flush_events(struct gendisk *disk, unsigned int mask)
 {

diff --git a/block/ioctl.c b/block/ioctl.c
index 22f394d118c302e9104dbf56cacf601ad74ea641..18adf9b16a30f6e68ac4caad62da8459db31146d 100644 (file)
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -99,9 +99,9 @@ static int blkdev_reread_part(struct block_device *bdev)
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
        ret = bdev_disk_changed(bdev, false);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
 
        return ret;
 }

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 573ef5a03fc10447f2907a42e63993428d9b0ded..e50b5ca17df5507009d4ba45998bf9d58c51363b 100644 (file)
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -328,7 +328,7 @@ int hd_ref_init(struct hd_struct *part)
 }
 
 /*
- * Must be called either with bd_mutex held, before a disk can be opened or
+ * Must be called either with disk->mutex held, before a disk can be opened or
  * after all disk users are gone.
  */
 void delete_partition(struct hd_struct *part)
@@ -363,7 +363,7 @@ static ssize_t whole_disk_show(struct device *dev,
 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
 
 /*
- * Must be called either with bd_mutex held, before a disk can be opened or
+ * Must be called either with disk->mutex held, before a disk can be opened or
  * after all disk users are gone.
  */
 static struct hd_struct *add_partition(struct gendisk *disk, int partno,
@@ -530,15 +530,15 @@ int bdev_add_partition(struct block_device *bdev, int partno,
 {
        struct hd_struct *part;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
        if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
-               mutex_unlock(&bdev->bd_mutex);
+               mutex_unlock(&bdev->bd_disk->mutex);
                return -EBUSY;
        }
 
        part = add_partition(bdev->bd_disk, partno, start, length,
                        ADDPART_FLAG_NONE, NULL);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
        return PTR_ERR_OR_ZERO(part);
 }
 
@@ -552,8 +552,7 @@ int bdev_del_partition(struct block_device *bdev, int partno)
        if (!bdevp)
                return -ENXIO;
 
-       mutex_lock(&bdevp->bd_mutex);
-       mutex_lock_nested(&bdev->bd_mutex, 1);
+       mutex_lock(&bdev->bd_disk->mutex);
 
        ret = -ENXIO;
        part = disk_get_part(bdev->bd_disk, partno);
@@ -570,8 +569,7 @@ int bdev_del_partition(struct block_device *bdev, int partno)
        delete_partition(part);
        ret = 0;
 out_unlock:
-       mutex_unlock(&bdev->bd_mutex);
-       mutex_unlock(&bdevp->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
        bdput(bdevp);
        if (part)
                disk_put_part(part);
@@ -594,8 +592,7 @@ int bdev_resize_partition(struct block_device *bdev, int partno,
        if (!bdevp)
                goto out_put_part;
 
-       mutex_lock(&bdevp->bd_mutex);
-       mutex_lock_nested(&bdev->bd_mutex, 1);
+       mutex_lock(&bdev->bd_disk->mutex);
 
        ret = -EINVAL;
        if (start != part->start_sect)
@@ -609,8 +606,7 @@ int bdev_resize_partition(struct block_device *bdev, int partno,
 
        ret = 0;
 out_unlock:
-       mutex_unlock(&bdevp->bd_mutex);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
        bdput(bdevp);
 out_put_part:
        disk_put_part(part);

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 22c5f0192ff777488502f6042a482194949dfe8c..cd192e1d906fcb456b8a0f45d0507c8254875928 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -651,9 +651,9 @@ static void loop_reread_partitions(struct loop_device *lo,
 {
        int rc;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
        rc = bdev_disk_changed(bdev, false);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
        if (rc)
                pr_warn("%s: partition scan of loop%d (%s) failed (rc=%d)\n",
                        __func__, lo->lo_number, lo->lo_file_name, rc);
@@ -746,7 +746,7 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
        mutex_unlock(&loop_ctl_mutex);
        /*
         * We must drop file reference outside of loop_ctl_mutex as dropping
-        * the file ref can take bd_mutex which creates circular locking
+        * the file ref can take disk->mutex which creates circular locking
         * dependency.
         */
        fput(old_file);
@@ -1261,7 +1261,7 @@ out_unlock:
        mutex_unlock(&loop_ctl_mutex);
        if (partscan) {
                /*
-                * bd_mutex has been held already in release path, so don't
+                * disk->mutex has been held already in release path, so don't
                 * acquire it if this function is called in such case.
                 *
                 * If the reread partition isn't from release path, lo_refcnt
@@ -1269,10 +1269,10 @@ out_unlock:
                 * current holder is released.
                 */
                if (!release)
-                       mutex_lock(&bdev->bd_mutex);
+                       mutex_lock(&bdev->bd_disk->mutex);
                err = bdev_disk_changed(bdev, false);
                if (!release)
-                       mutex_unlock(&bdev->bd_mutex);
+                       mutex_unlock(&bdev->bd_disk->mutex);
                if (err)
                        pr_warn("%s: partition scan of loop%d failed (rc=%d)\n",
                                __func__, lo_number, err);
@@ -1300,7 +1300,7 @@ out_unlock:
         * Need not hold loop_ctl_mutex to fput backing file.
         * Calling fput holding loop_ctl_mutex triggers a circular
         * lock dependency possibility warning as fput can take
-        * bd_mutex which is usually taken before loop_ctl_mutex.
+        * disk->mutex which is usually taken before loop_ctl_mutex.
         */
        if (filp)
                fput(filp);

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 79521e33d30ed5637b1ca983143ca7388cf28811..5b1f99ca77b734865e85428ef2e5762acd6f36a6 100644 (file)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2162,7 +2162,7 @@ static void blkfront_closing(struct blkfront_info *info)
                return;
        }
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&info->gd->mutex);
 
        if (bdev->bd_openers) {
                xenbus_dev_error(xbdev, -EBUSY,
@@ -2173,7 +2173,7 @@ static void blkfront_closing(struct blkfront_info *info)
                xenbus_frontend_closed(xbdev);
        }
 
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&info->gd->mutex);
        bdput(bdev);
 }
 
@@ -2536,7 +2536,7 @@ static int blkfront_remove(struct xenbus_device *xbdev)
         * isn't closed yet, we let release take care of it.
         */
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&info->gd->mutex);
        info = disk->private_data;
 
        dev_warn(disk_to_dev(disk),
@@ -2551,7 +2551,7 @@ static int blkfront_remove(struct xenbus_device *xbdev)
                mutex_unlock(&blkfront_mutex);
        }
 
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&info->gd->mutex);
        bdput(bdev);
 
        return 0;

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 3641434a9b154d247bb242834bfd9d8fa4029ce7..1650a5e8a79af8ef679f62378cfb67691e01b237 100644 (file)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1771,12 +1771,12 @@ static ssize_t reset_store(struct device *dev,
        if (!bdev)
                return -ENOMEM;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&zram->disk->mutex);
        if (bdev->bd_openers)
                ret = -EBUSY;
        else
                zram_reset_device(zram);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&zram->disk->mutex);
        bdput(bdev);
 
        return ret ? ret : len;

diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index f2fd46daa7604583b1c3bebaba86b484bca901c7..22927984d5634f2fda72a3b2fcc9ba4b3a6468f0 100644 (file)
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -111,7 +111,7 @@ struct zram {
        /*
         * zram is claimed so open request will be failed
         */
-       bool claim; /* Protected by bdev->bd_mutex */
+       bool claim; /* Protected by bdev->bd_disk->mutex */
        struct file *backing_dev;
 #ifdef CONFIG_ZRAM_WRITEBACK
        spinlock_t wb_limit_lock;

diff --git a/drivers/md/md.h b/drivers/md/md.h
index ccfb69868c2ec95c90ad234c332e5b5eca38c18d..28712d3498de2c3f93d1e434b7ca5f578bfdc827 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -394,11 +394,8 @@ struct mddev {
        /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so
         * that we are never stopping an array while it is open.
         * 'reconfig_mutex' protects all other reconfiguration.
-        * These locks are separate due to conflicting interactions
-        * with bdev->bd_mutex.
-        * Lock ordering is:
-        *  reconfig_mutex -> bd_mutex
-        *  bd_mutex -> open_mutex:  e.g. __blkdev_get -> md_open
+        * These locks are separate due to historically conflicting
+        * interactions with block layer locks.
         */
        struct mutex                    open_mutex;
        struct mutex                    reconfig_mutex;

diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
index a9698fba9b76ce42681aba20399cdf88d8cbda1d..7b5f475b500e8c16706bfe1afab1e7d6b3282d22 100644 (file)
--- a/drivers/s390/block/dasd_genhd.c
+++ b/drivers/s390/block/dasd_genhd.c
@@ -109,9 +109,9 @@ int dasd_scan_partitions(struct dasd_block *block)
                return -ENODEV;
        }
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
        rc = bdev_disk_changed(bdev, false);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
        if (rc)
                DBF_DEV_EVENT(DBF_ERR, block->base,
                                "scan partitions error, rc %d", rc);
@@ -145,9 +145,9 @@ void dasd_destroy_partitions(struct dasd_block *block)
        bdev = block->bdev;
        block->bdev = NULL;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
        blk_drop_partitions(bdev);
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
 
        /* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
        blkdev_put(bdev, FMODE_READ);

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 679c2c02504763ba31a21c425d58bdfca02baba8..68c752ef3ed5759749525dc6b6c1818882c37f17 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1398,7 +1398,7 @@ static void sd_uninit_command(struct scsi_cmnd *SCpnt)
  *     In the latter case @inode and @filp carry an abridged amount
  *     of information as noted above.
  *
- *     Locking: called with bdev->bd_mutex held.
+ *     Locking: called with bdev->bd_disk->mutex held.
  **/
 static int sd_open(struct block_device *bdev, fmode_t mode)
 {
@@ -1474,7 +1474,7 @@ error_out:
  *     Note: may block (uninterruptible) if error recovery is underway
  *     on this disk.
  *
- *     Locking: called with bdev->bd_mutex held.
+ *     Locking: called with bdev->bd_disk->mutex held.
  **/
 static void sd_release(struct gendisk *disk, fmode_t mode)
 {

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 14b6dbfa9dda2af73508db89b9bf1dd5c8d8f21f..4b59ace9632f65e669e3d5542e54055e52b28e35 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -803,7 +803,6 @@ static void init_once(void *foo)
        struct block_device *bdev = &ei->bdev;
 
        memset(bdev, 0, sizeof(*bdev));
-       mutex_init(&bdev->bd_mutex);
 #ifdef CONFIG_SYSFS
        INIT_LIST_HEAD(&bdev->bd_holder_disks);
 #endif
@@ -1204,7 +1203,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
        struct bd_holder_disk *holder;
        int ret = 0;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
 
        WARN_ON_ONCE(!bdev->bd_holder);
 
@@ -1249,7 +1248,7 @@ out_del:
 out_free:
        kfree(holder);
 out_unlock:
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
        return ret;
 }
 EXPORT_SYMBOL_GPL(bd_link_disk_holder);
@@ -1268,7 +1267,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
 {
        struct bd_holder_disk *holder;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
 
        holder = bd_find_holder_disk(bdev, disk);
 
@@ -1281,7 +1280,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
                kfree(holder);
        }
 
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
 }
 EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
 #endif
@@ -1293,7 +1292,7 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate)
        struct gendisk *disk = bdev->bd_disk;
        int ret;
 
-       lockdep_assert_held(&bdev->bd_mutex);
+       lockdep_assert_held(&bdev->bd_disk->mutex);
 
        clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 
@@ -1357,13 +1356,6 @@ out_unlock:
        return -ENXIO;
 }
 
-/*
- * bd_mutex locking:
- *
- *  mutex_lock(part->bd_mutex)
- *    mutex_lock_nested(whole->bd_mutex, 1)
- */
-
 static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
                int for_part)
 {
@@ -1377,15 +1369,18 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
        if (ret)
                goto out;
 
-       if (!for_part && (mode & FMODE_EXCL)) {
-               WARN_ON_ONCE(!holder);
-               ret = bd_prepare_to_claim(bdev, holder);
-               if (ret)
-                       goto out_put_disk;
+       if (!for_part) {
+               if (mode & FMODE_EXCL) {
+                       WARN_ON_ONCE(!holder);
+                       ret = bd_prepare_to_claim(bdev, holder);
+                       if (ret)
+                               goto out_put_disk;
+               }
+
+               disk_block_events(disk);
+               mutex_lock(&disk->mutex);
        }
 
-       disk_block_events(disk);
-       mutex_lock_nested(&bdev->bd_mutex, for_part);
        if (!bdev->bd_openers) {
                first_open = true;
 
@@ -1470,10 +1465,14 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
                        unblock_events = false;
                }
        }
-       mutex_unlock(&bdev->bd_mutex);
 
-       if (unblock_events)
-               disk_unblock_events(disk);
+       if (!for_part) {
+               mutex_unlock(&disk->mutex);
+
+               if (unblock_events)
+                       disk_unblock_events(disk);
+       }
+
 
        /* only one opener holds the module reference */
        if (!first_open)
@@ -1486,10 +1485,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
        if (bdev_is_partition(bdev))
                __blkdev_put(bdev_whole(bdev), mode, 1);
  out_unlock_bdev:
-       if (!for_part && (mode & FMODE_EXCL))
-               bd_abort_claiming(bdev, holder);
-       mutex_unlock(&bdev->bd_mutex);
-       disk_unblock_events(disk);
+       if (!for_part) {
+               if (mode & FMODE_EXCL)
+                       bd_abort_claiming(bdev, holder);
+               mutex_unlock(&disk->mutex);
+               disk_unblock_events(disk);
+       }
  out_put_disk:
        module_put(disk->fops->owner);
        if (need_restart)
@@ -1668,9 +1669,10 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
        if (bdev->bd_openers == 1)
                sync_blockdev(bdev);
 
-       mutex_lock_nested(&bdev->bd_mutex, for_part);
        if (for_part)
                bdev->bd_part_count--;
+       else
+               mutex_lock(&disk->mutex);
 
        if (!--bdev->bd_openers) {
                WARN_ON_ONCE(bdev->bd_holders);
@@ -1691,7 +1693,8 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 
                module_put(disk->fops->owner);
        }
-       mutex_unlock(&bdev->bd_mutex);
+       if (!for_part)
+               mutex_unlock(&disk->mutex);
        bdput(bdev);
        if (victim)
                __blkdev_put(victim, mode, 1);
@@ -1699,7 +1702,7 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 
 void blkdev_put(struct block_device *bdev, fmode_t mode)
 {
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock(&bdev->bd_disk->mutex);
 
        if (mode & FMODE_EXCL) {
                struct block_device *whole = bdev_whole(bdev);
@@ -1707,7 +1710,7 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
 
                /*
                 * Release a claim on the device.  The holder fields
-                * are protected with bdev_lock.  bd_mutex is to
+                * are protected with bdev_lock.  disk->mutex is to
                 * synchronize disk_holder unlinking.
                 */
                spin_lock(&bdev_lock);
@@ -1739,7 +1742,7 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
         */
        disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE);
 
-       mutex_unlock(&bdev->bd_mutex);
+       mutex_unlock(&bdev->bd_disk->mutex);
 
        __blkdev_put(bdev, mode, 0);
 }
@@ -2039,10 +2042,10 @@ void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
                old_inode = inode;
                bdev = I_BDEV(inode);
 
-               mutex_lock(&bdev->bd_mutex);
+               mutex_lock(&bdev->bd_disk->mutex);
                if (bdev->bd_openers)
                        func(bdev, arg);
-               mutex_unlock(&bdev->bd_mutex);
+               mutex_unlock(&bdev->bd_disk->mutex);
 
                spin_lock(&blockdev_superblock->s_inode_list_lock);
        }

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a6406b3b8c2b4f2e27b7245e39f306a0d5a909ac..ce43732f945f456c05d81533e06bffc7c401c165 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1237,7 +1237,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
        lockdep_assert_held(&uuid_mutex);
        /*
         * The device_list_mutex cannot be taken here in case opening the
-        * underlying device takes further locks like bd_mutex.
+        * underlying device takes further locks like disk->mutex.
         *
         * We also don't need the lock here as this is called during mount and
         * exclusion is provided by uuid_mutex

diff --git a/fs/super.c b/fs/super.c
index 98bb0629ee108e87ff8876457b535442addf695e..b327a82bc1946b17143676bb5e6d01f254501d0d 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -1328,9 +1328,9 @@ int get_tree_bdev(struct fs_context *fc,
                }
 
                /*
-                * s_umount nests inside bd_mutex during
+                * s_umount nests inside disk->mutex during
                 * __invalidate_device().  blkdev_put() acquires
-                * bd_mutex and can't be called under s_umount.  Drop
+                * disk->mutex and can't be called under s_umount.  Drop
                 * s_umount temporarily.  This is safe as we're
                 * holding an active reference.
                 */
@@ -1403,9 +1403,9 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
                }
 
                /*
-                * s_umount nests inside bd_mutex during
+                * s_umount nests inside disk->mutex during
                 * __invalidate_device().  blkdev_put() acquires
-                * bd_mutex and can't be called under s_umount.  Drop
+                * disk->mutex and can't be called under s_umount.  Drop
                 * s_umount temporarily.  This is safe as we're
                 * holding an active reference.
                 */

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 041caca25fc7872c936ced4d62ccf8bc87ae54b2..0735e335ca6c0af939b1827f4d26b2925d664764 100644 (file)
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -24,7 +24,6 @@ struct block_device {
        int                     bd_openers;
        struct inode *          bd_inode;       /* will die */
        struct super_block *    bd_super;
-       struct mutex            bd_mutex;       /* open/close mutex */
        void *                  bd_claiming;
        void *                  bd_holder;
        int                     bd_holders;

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index e01618dfafc05c7603549cfbcced7f461ab753be..bc0469cc8fb0dc203acbb3bdd231b0ccfa422ff5 100644 (file)
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -186,6 +186,7 @@ struct gendisk {
        unsigned long state;
 #define GD_NEED_PART_SCAN              0
        struct rw_semaphore lookup_sem;
+       struct mutex mutex;             /* open/close mutex */
        struct kobject *slave_dir;
 
        struct timer_rand_state *random;