Messages in this thread | | | Date | Sun, 5 Apr 2015 09:12:41 -0700 | From | Christoph Hellwig <> | Subject | Re: [PATCH 1/6] block: export blkdev_reread_part() |
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> +/* > + * This is exported as API for block driver, can be called > + * with requiring bd_mutex or not. > + */ > +int __blkdev_reread_part(struct block_device *bdev, bool lock) > { > struct gendisk *disk = bdev->bd_disk; > int res; > @@ -159,12 +163,14 @@ static int blkdev_reread_part(struct block_device *bdev) > return -EINVAL; > if (!capable(CAP_SYS_ADMIN)) > return -EACCES; > - if (!mutex_trylock(&bdev->bd_mutex)) > + if (lock && !mutex_trylock(&bdev->bd_mutex)) > return -EBUSY;
Please don't add funtions that do conditional locking, instead move all the code into blkdev_reread_part_nolock, and then wrap it:
int blkdev_reread_part(struct block_device *bdev) { if (!mutex_trylock(&bdev->bd_mutex)) return -EBUSY; blkdev_reread_part_nolock(bdev); mutex_unlock(&bdev->bd_mutex); }
Please also add a lockdep_assert_held to blkdev_reread_part_nolock to ensure callers actually do hold the lock.
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