Messages in this thread | | | From | Ming Lei <> | Subject | [PATCH 0/6] block: reread partitions changes and fix for loop | Date | Sun, 5 Apr 2015 15:24:42 +0800 |
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Recently there are several reports about loop partition scanning failure[1][2].
For loop, the root cause is one ABBA and one AA lock dependency issue, and the two are fixed by patch 2 and patch 3 each.
Another reason is from the trylock in blkdev_reread_part(), which may cause partition scanning failure too sometimes when another task is holding the bd_mutex. In the discussion[1], both Tejun and Christoph suggests to replace the trylock with mutex_lock in blkdev_reread_part(), also Christoph suggests to export blkdev_reread_part.
Following the discussion, this patchset exports blkdev_reread_part(), and introduces blkdev_reread_part_nolock() for fixing loop's AA lock issue. Then ioctl_by_bdev(BLKRRPART) in loop, nbd and dasd is replaced with blkdev_reread_part(). In the last patch, trylock in __blkdev_reread_part() is replaced with mutex_lock, and some analysis is provided about the conversion.
[1], https://lkml.org/lkml/2015/1/26/137 [2], https://lkml.org/lkml/2015/3/31/888
Thanks, Ming Lei
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