diff options
| -rw-r--r-- | fs/block_dev.c | 51 |
1 files changed, 29 insertions, 22 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 36c38f48a4ed..19f5f153ddb8 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -900,7 +900,10 @@ 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_get(struct block_device *bdev, mode_t mode, unsigned flags, + int for_part); + +static int do_open(struct block_device *bdev, struct file *file, int for_part) { struct module *owner = NULL; struct gendisk *disk; @@ -944,25 +947,21 @@ 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); + BUG_ON(for_part); + ret = __blkdev_get(whole, file->f_mode, file->f_flags, 1); if (ret) goto out_first; bdev->bd_contains = whole; - mutex_lock(&whole->bd_mutex); - whole->bd_part_count++; p = disk->part[part - 1]; bdev->bd_inode->i_data.backing_dev_info = whole->bd_inode->i_data.backing_dev_info; if (!(disk->flags & GENHD_FL_UP) || !p || !p->nr_sects) { - whole->bd_part_count--; - mutex_unlock(&whole->bd_mutex); ret = -ENXIO; goto out_first; } kobject_get(&p->kobj); bdev->bd_part = p; bd_set_size(bdev, (loff_t) p->nr_sects << 9); - mutex_unlock(&whole->bd_mutex); } } else { put_disk(disk); @@ -975,13 +974,11 @@ 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); - bdev->bd_contains->bd_part_count++; - mutex_unlock(&bdev->bd_contains->bd_mutex); } } bdev->bd_openers++; + if (for_part) + bdev->bd_part_count++; mutex_unlock(&bdev->bd_mutex); unlock_kernel(); return 0; @@ -1002,7 +999,8 @@ out: return ret; } -int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags) +static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags, + int for_part) { /* * This crockload is due to bad choice of ->open() type. @@ -1017,9 +1015,13 @@ 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, for_part); } +int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags) +{ + return __blkdev_get(bdev, mode, flags, 0); +} EXPORT_SYMBOL(blkdev_get); static int blkdev_open(struct inode * inode, struct file * filp) @@ -1039,7 +1041,7 @@ static int blkdev_open(struct inode * inode, struct file * filp) if (bdev == NULL) return -ENOMEM; - res = do_open(bdev, filp); + res = do_open(bdev, filp, 0); if (res) return res; @@ -1053,14 +1055,18 @@ static int blkdev_open(struct inode * inode, struct file * filp) return res; } -int blkdev_put(struct block_device *bdev) +static int __blkdev_put(struct block_device *bdev, int for_part) { int ret = 0; struct inode *bd_inode = bdev->bd_inode; struct gendisk *disk = bdev->bd_disk; + struct block_device *victim = NULL; mutex_lock(&bdev->bd_mutex); lock_kernel(); + if (for_part) + bdev->bd_part_count--; + if (!--bdev->bd_openers) { sync_blockdev(bdev); kill_bdev(bdev); @@ -1068,10 +1074,6 @@ int blkdev_put(struct block_device *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; @@ -1085,17 +1087,22 @@ int blkdev_put(struct block_device *bdev) } 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); - } + if (bdev != bdev->bd_contains) + victim = bdev->bd_contains; bdev->bd_contains = NULL; } unlock_kernel(); mutex_unlock(&bdev->bd_mutex); bdput(bdev); + if (victim) + __blkdev_put(victim, 1); return ret; } +int blkdev_put(struct block_device *bdev) +{ + return __blkdev_put(bdev, 0); +} EXPORT_SYMBOL(blkdev_put); static int blkdev_close(struct inode * inode, struct file * filp) |