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-rw-r--r--fs/block_dev.c51
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)