Messages in this thread | | | From | Ming Lei <> | Subject | [PATCH v2 0/7] block: reread partitions changes and fix for loop | Date | Sat, 11 Apr 2015 19:30:06 +0800 |
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Hi Guys,
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() 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.
V2: - only print debug message in case of error (7/7) - add tested-by, acked-by
V1: - introduce __blkdev_reread_part(), and use lockdep_assert_held()(1/7) - replace lo_open_mutex with atomic reference count, plus freezing queue(2/7) - add comment about detecting release path(3/7) - remove dead code in dasd(7/7)
block/ioctl.c | 37 +++++++++++++++++++++++++---- drivers/block/loop.c | 49 +++++++++++++++++++++++++++++---------- drivers/block/loop.h | 2 +- drivers/block/nbd.c | 2 +- drivers/s390/block/dasd_genhd.c | 19 ++++----------- include/linux/fs.h | 3 +++ 6 files changed, 79 insertions(+), 33 deletions(-)
[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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