On 11/28/20 5:14 PM, Christoph Hellwig wrote:
All of the current callers already have a reference, but to prepare for
additional users ensure bdgrab returns NULL if the block device is beeing
freed.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/block_dev.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index d707ab376da86e..962fabe8a67b83 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -894,10 +894,14 @@ static struct block_device *bdget(dev_t dev)
/**
* bdgrab -- Grab a reference to an already referenced block device
* @bdev: Block device to grab a reference to.
+ *
+ * Returns the block_device with an additional reference when successful,
+ * or NULL if the inode is already beeing freed.
*/
struct block_device *bdgrab(struct block_device *bdev)
{
- ihold(bdev->bd_inode);
+ if (!igrab(bdev->bd_inode))
+ return NULL;
return bdev;
}
EXPORT_SYMBOL(bdgrab);
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
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