ocfs2: Add dentry tracking API
[pandora-kernel.git] / fs / block_dev.c
index 9633a49..045f988 100644 (file)
@@ -739,7 +739,7 @@ static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
        if (!bo)
                return -ENOMEM;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
        res = bd_claim(bdev, holder);
        if (res || !add_bd_holder(bdev, bo))
                free_bd_holder(bo);
@@ -764,7 +764,7 @@ static void bd_release_from_kobject(struct block_device *bdev,
        if (!kobj)
                return;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
        bd_release(bdev);
        if ((bo = del_bd_holder(bdev, kobj)))
                free_bd_holder(bo);
@@ -822,6 +822,22 @@ struct block_device *open_by_devnum(dev_t dev, unsigned mode)
 
 EXPORT_SYMBOL(open_by_devnum);
 
+static int
+blkdev_get_partition(struct block_device *bdev, mode_t mode, unsigned flags);
+
+struct block_device *open_partition_by_devnum(dev_t dev, unsigned mode)
+{
+       struct block_device *bdev = bdget(dev);
+       int err = -ENOMEM;
+       int flags = mode & FMODE_WRITE ? O_RDWR : O_RDONLY;
+       if (bdev)
+               err = blkdev_get_partition(bdev, mode, flags);
+       return err ? ERR_PTR(err) : bdev;
+}
+
+EXPORT_SYMBOL(open_partition_by_devnum);
+
+
 /*
  * This routine checks whether a removable media has been changed,
  * and invalidates all buffer-cache-entries in that case. This
@@ -868,7 +884,66 @@ void bd_set_size(struct block_device *bdev, loff_t size)
 }
 EXPORT_SYMBOL(bd_set_size);
 
-static int do_open(struct block_device *bdev, struct file *file)
+static int __blkdev_put(struct block_device *bdev, unsigned int subclass)
+{
+       int ret = 0;
+       struct inode *bd_inode = bdev->bd_inode;
+       struct gendisk *disk = bdev->bd_disk;
+
+       mutex_lock_nested(&bdev->bd_mutex, subclass);
+       lock_kernel();
+       if (!--bdev->bd_openers) {
+               sync_blockdev(bdev);
+               kill_bdev(bdev);
+       }
+       if (bdev->bd_contains == bdev) {
+               if (disk->fops->release)
+                       ret = disk->fops->release(bd_inode, NULL);
+       } else {
+               mutex_lock_nested(&bdev->bd_contains->bd_mutex,
+                                 subclass + 1);
+               bdev->bd_contains->bd_part_count--;
+               mutex_unlock(&bdev->bd_contains->bd_mutex);
+       }
+       if (!bdev->bd_openers) {
+               struct module *owner = disk->fops->owner;
+
+               put_disk(disk);
+               module_put(owner);
+
+               if (bdev->bd_contains != bdev) {
+                       kobject_put(&bdev->bd_part->kobj);
+                       bdev->bd_part = NULL;
+               }
+               bdev->bd_disk = NULL;
+               bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
+               if (bdev != bdev->bd_contains)
+                       __blkdev_put(bdev->bd_contains, subclass + 1);
+               bdev->bd_contains = NULL;
+       }
+       unlock_kernel();
+       mutex_unlock(&bdev->bd_mutex);
+       bdput(bdev);
+       return ret;
+}
+
+int blkdev_put(struct block_device *bdev)
+{
+       return __blkdev_put(bdev, BD_MUTEX_NORMAL);
+}
+EXPORT_SYMBOL(blkdev_put);
+
+int blkdev_put_partition(struct block_device *bdev)
+{
+       return __blkdev_put(bdev, BD_MUTEX_PARTITION);
+}
+EXPORT_SYMBOL(blkdev_put_partition);
+
+static int
+blkdev_get_whole(struct block_device *bdev, mode_t mode, unsigned flags);
+
+static int
+do_open(struct block_device *bdev, struct file *file, unsigned int subclass)
 {
        struct module *owner = NULL;
        struct gendisk *disk;
@@ -885,7 +960,8 @@ static int do_open(struct block_device *bdev, struct file *file)
        }
        owner = disk->fops->owner;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock_nested(&bdev->bd_mutex, subclass);
+
        if (!bdev->bd_openers) {
                bdev->bd_disk = disk;
                bdev->bd_contains = bdev;
@@ -912,11 +988,11 @@ static int do_open(struct block_device *bdev, struct file *file)
                        ret = -ENOMEM;
                        if (!whole)
                                goto out_first;
-                       ret = blkdev_get(whole, file->f_mode, file->f_flags);
+                       ret = blkdev_get_whole(whole, file->f_mode, file->f_flags);
                        if (ret)
                                goto out_first;
                        bdev->bd_contains = whole;
-                       mutex_lock(&whole->bd_mutex);
+                       mutex_lock_nested(&whole->bd_mutex, BD_MUTEX_WHOLE);
                        whole->bd_part_count++;
                        p = disk->part[part - 1];
                        bdev->bd_inode->i_data.backing_dev_info =
@@ -944,7 +1020,8 @@ static int do_open(struct block_device *bdev, struct file *file)
                        if (bdev->bd_invalidated)
                                rescan_partitions(bdev->bd_disk, bdev);
                } else {
-                       mutex_lock(&bdev->bd_contains->bd_mutex);
+                       mutex_lock_nested(&bdev->bd_contains->bd_mutex,
+                                         BD_MUTEX_PARTITION);
                        bdev->bd_contains->bd_part_count++;
                        mutex_unlock(&bdev->bd_contains->bd_mutex);
                }
@@ -958,7 +1035,7 @@ out_first:
        bdev->bd_disk = NULL;
        bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
        if (bdev != bdev->bd_contains)
-               blkdev_put(bdev->bd_contains);
+               __blkdev_put(bdev->bd_contains, BD_MUTEX_WHOLE);
        bdev->bd_contains = NULL;
        put_disk(disk);
        module_put(owner);
@@ -985,11 +1062,49 @@ int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags)
        fake_file.f_dentry = &fake_dentry;
        fake_dentry.d_inode = bdev->bd_inode;
 
-       return do_open(bdev, &fake_file);
+       return do_open(bdev, &fake_file, BD_MUTEX_NORMAL);
 }
 
 EXPORT_SYMBOL(blkdev_get);
 
+static int
+blkdev_get_whole(struct block_device *bdev, mode_t mode, unsigned flags)
+{
+       /*
+        * This crockload is due to bad choice of ->open() type.
+        * It will go away.
+        * For now, block device ->open() routine must _not_
+        * examine anything in 'inode' argument except ->i_rdev.
+        */
+       struct file fake_file = {};
+       struct dentry fake_dentry = {};
+       fake_file.f_mode = mode;
+       fake_file.f_flags = flags;
+       fake_file.f_dentry = &fake_dentry;
+       fake_dentry.d_inode = bdev->bd_inode;
+
+       return do_open(bdev, &fake_file, BD_MUTEX_WHOLE);
+}
+
+static int
+blkdev_get_partition(struct block_device *bdev, mode_t mode, unsigned flags)
+{
+       /*
+        * This crockload is due to bad choice of ->open() type.
+        * It will go away.
+        * For now, block device ->open() routine must _not_
+        * examine anything in 'inode' argument except ->i_rdev.
+        */
+       struct file fake_file = {};
+       struct dentry fake_dentry = {};
+       fake_file.f_mode = mode;
+       fake_file.f_flags = flags;
+       fake_file.f_dentry = &fake_dentry;
+       fake_dentry.d_inode = bdev->bd_inode;
+
+       return do_open(bdev, &fake_file, BD_MUTEX_PARTITION);
+}
+
 static int blkdev_open(struct inode * inode, struct file * filp)
 {
        struct block_device *bdev;
@@ -1005,7 +1120,7 @@ static int blkdev_open(struct inode * inode, struct file * filp)
 
        bdev = bd_acquire(inode);
 
-       res = do_open(bdev, filp);
+       res = do_open(bdev, filp, BD_MUTEX_NORMAL);
        if (res)
                return res;
 
@@ -1019,51 +1134,6 @@ static int blkdev_open(struct inode * inode, struct file * filp)
        return res;
 }
 
-int blkdev_put(struct block_device *bdev)
-{
-       int ret = 0;
-       struct inode *bd_inode = bdev->bd_inode;
-       struct gendisk *disk = bdev->bd_disk;
-
-       mutex_lock(&bdev->bd_mutex);
-       lock_kernel();
-       if (!--bdev->bd_openers) {
-               sync_blockdev(bdev);
-               kill_bdev(bdev);
-       }
-       if (bdev->bd_contains == bdev) {
-               if (disk->fops->release)
-                       ret = disk->fops->release(bd_inode, NULL);
-       } else {
-               mutex_lock(&bdev->bd_contains->bd_mutex);
-               bdev->bd_contains->bd_part_count--;
-               mutex_unlock(&bdev->bd_contains->bd_mutex);
-       }
-       if (!bdev->bd_openers) {
-               struct module *owner = disk->fops->owner;
-
-               put_disk(disk);
-               module_put(owner);
-
-               if (bdev->bd_contains != bdev) {
-                       kobject_put(&bdev->bd_part->kobj);
-                       bdev->bd_part = NULL;
-               }
-               bdev->bd_disk = NULL;
-               bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
-               if (bdev != bdev->bd_contains) {
-                       blkdev_put(bdev->bd_contains);
-               }
-               bdev->bd_contains = NULL;
-       }
-       unlock_kernel();
-       mutex_unlock(&bdev->bd_mutex);
-       bdput(bdev);
-       return ret;
-}
-
-EXPORT_SYMBOL(blkdev_put);
-
 static int blkdev_close(struct inode * inode, struct file * filp)
 {
        struct block_device *bdev = I_BDEV(filp->f_mapping->host);