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-rw-r--r--fs/block_dev.c58
1 files changed, 40 insertions, 18 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index bc8f27cc448..36c0e7af9d0 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -642,34 +642,47 @@ static void free_bd_holder(struct bd_holder *bo)
}
/**
+ * find_bd_holder - find matching struct bd_holder from the block device
+ *
+ * @bdev: struct block device to be searched
+ * @bo: target struct bd_holder
+ *
+ * Returns matching entry with @bo in @bdev->bd_holder_list.
+ * If found, increment the reference count and return the pointer.
+ * If not found, returns NULL.
+ */
+static struct bd_holder *find_bd_holder(struct block_device *bdev,
+ struct bd_holder *bo)
+{
+ struct bd_holder *tmp;
+
+ list_for_each_entry(tmp, &bdev->bd_holder_list, list)
+ if (tmp->sdir == bo->sdir) {
+ tmp->count++;
+ return tmp;
+ }
+
+ return NULL;
+}
+
+/**
* add_bd_holder - create sysfs symlinks for bd_claim() relationship
*
* @bdev: block device to be bd_claimed
* @bo: preallocated and initialized by alloc_bd_holder()
*
- * If there is no matching entry with @bo in @bdev->bd_holder_list,
- * add @bo to the list, create symlinks.
+ * Add @bo to @bdev->bd_holder_list, create symlinks.
*
- * Returns 0 if symlinks are created or already there.
- * Returns -ve if something fails and @bo can be freed.
+ * Returns 0 if symlinks are created.
+ * Returns -ve if something fails.
*/
static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo)
{
- struct bd_holder *tmp;
int ret;
if (!bo)
return -EINVAL;
- list_for_each_entry(tmp, &bdev->bd_holder_list, list) {
- if (tmp->sdir == bo->sdir) {
- tmp->count++;
- /* We've already done what we need to do here. */
- free_bd_holder(bo);
- return 0;
- }
- }
-
if (!bd_holder_grab_dirs(bdev, bo))
return -EBUSY;
@@ -740,7 +753,7 @@ static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
struct kobject *kobj)
{
int res;
- struct bd_holder *bo;
+ struct bd_holder *bo, *found;
if (!kobj)
return -EINVAL;
@@ -751,9 +764,16 @@ static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
res = bd_claim(bdev, holder);
- if (res == 0)
- res = add_bd_holder(bdev, bo);
- if (res)
+ if (res == 0) {
+ found = find_bd_holder(bdev, bo);
+ if (found == NULL) {
+ res = add_bd_holder(bdev, bo);
+ if (res)
+ bd_release(bdev);
+ }
+ }
+
+ if (res || found)
free_bd_holder(bo);
mutex_unlock(&bdev->bd_mutex);
@@ -1131,6 +1151,8 @@ static int blkdev_open(struct inode * inode, struct file * filp)
filp->f_flags |= O_LARGEFILE;
bdev = bd_acquire(inode);
+ if (bdev == NULL)
+ return -ENOMEM;
res = do_open(bdev, filp, BD_MUTEX_NORMAL);
if (res)