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-rw-r--r--fs/block_dev.c38
1 files changed, 28 insertions, 10 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index f5958f413bd1..028d9fb9c2d5 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -300,10 +300,10 @@ static struct super_operations bdev_sops = {
.clear_inode = bdev_clear_inode,
};
-static struct super_block *bd_get_sb(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int bd_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
- return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576);
+ return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576, mnt);
}
static struct file_system_type bd_type = {
@@ -414,21 +414,31 @@ EXPORT_SYMBOL(bdput);
static struct block_device *bd_acquire(struct inode *inode)
{
struct block_device *bdev;
+
spin_lock(&bdev_lock);
bdev = inode->i_bdev;
- if (bdev && igrab(bdev->bd_inode)) {
+ if (bdev) {
+ atomic_inc(&bdev->bd_inode->i_count);
spin_unlock(&bdev_lock);
return bdev;
}
spin_unlock(&bdev_lock);
+
bdev = bdget(inode->i_rdev);
if (bdev) {
spin_lock(&bdev_lock);
- if (inode->i_bdev)
- __bd_forget(inode);
- inode->i_bdev = bdev;
- inode->i_mapping = bdev->bd_inode->i_mapping;
- list_add(&inode->i_devices, &bdev->bd_inodes);
+ if (!inode->i_bdev) {
+ /*
+ * We take an additional bd_inode->i_count for inode,
+ * and it's released in clear_inode() of inode.
+ * So, we can access it via ->i_mapping always
+ * without igrab().
+ */
+ atomic_inc(&bdev->bd_inode->i_count);
+ inode->i_bdev = bdev;
+ inode->i_mapping = bdev->bd_inode->i_mapping;
+ list_add(&inode->i_devices, &bdev->bd_inodes);
+ }
spin_unlock(&bdev_lock);
}
return bdev;
@@ -438,10 +448,18 @@ static struct block_device *bd_acquire(struct inode *inode)
void bd_forget(struct inode *inode)
{
+ struct block_device *bdev = NULL;
+
spin_lock(&bdev_lock);
- if (inode->i_bdev)
+ if (inode->i_bdev) {
+ if (inode->i_sb != blockdev_superblock)
+ bdev = inode->i_bdev;
__bd_forget(inode);
+ }
spin_unlock(&bdev_lock);
+
+ if (bdev)
+ iput(bdev->bd_inode);
}
int bd_claim(struct block_device *bdev, void *holder)