linux/block
Tejun Heo e71bf0d0ee block: fix disk->part[] dereferencing race
disk->part[] is protected by its matching bdev's lock.  However,
non-critical accesses like collecting stats and printing out sysfs and
proc information used to be performed without any locking.  As
partitions can come and go dynamically, partitions can go away
underneath those non-critical accesses.  As some of those accesses are
writes, this theoretically can lead to silent corruption.

This patch fixes the race by using RCU for the partition array and dev
reference counter to hold partitions.

* Rename disk->part[] to disk->__part[] to make sure no one outside
  genhd layer proper accesses it directly.

* Use RCU for disk->__part[] dereferencing.

* Implement disk_{get|put}_part() which can be used to get and put
  partitions from gendisk respectively.

* Iterators are implemented to help iterate through all partitions
  safely.

* Functions which require RCU readlock are marked with _rcu suffix.

* Use disk_put_part() in __blkdev_put() instead of directly putting
  the contained kobject.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:06 +02:00
..
as-iosched.c Use WARN() in block/ 2008-07-26 12:00:07 -07:00
blk-barrier.c Allow elevators to sort/merge discard requests 2008-10-09 08:56:02 +02:00
blk-core.c block: fix disk->part[] dereferencing race 2008-10-09 08:56:06 +02:00
blk-exec.c Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. 2008-10-09 08:56:03 +02:00
blk-integrity.c Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. 2008-10-09 08:56:03 +02:00
blk-ioc.c cfq-iosched: fix RCU race in the cfq io_context destructor handling 2008-05-07 09:28:57 +02:00
blk-map.c Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. 2008-10-09 08:56:03 +02:00
blk-merge.c block: fix disk->part[] dereferencing race 2008-10-09 08:56:06 +02:00
blk-settings.c Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. 2008-10-09 08:56:03 +02:00
blk-sysfs.c block: sysfs store function needs to grab queue_lock and use queue_flag_*() 2008-05-07 09:09:39 +02:00
blk-tag.c Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. 2008-10-09 08:56:03 +02:00
blk.h block: Block layer data integrity support 2008-07-03 13:21:13 +02:00
blktrace.c blktrace: simplify flags handling in __blk_add_trace 2008-10-09 08:56:01 +02:00
bsg.c block: move cmdfilter from gendisk to request_queue 2008-08-27 09:50:19 +02:00
cfq-iosched.c cfq-iosched: get rid of enable_idle being unused warning 2008-07-03 13:21:14 +02:00
cmd-filter.c block: disable sysfs parts of the disk command filter 2008-09-11 14:20:23 +02:00
compat_ioctl.c Add BLKDISCARD ioctl to allow userspace to discard sectors 2008-10-09 08:56:02 +02:00
deadline-iosched.c deadline-iosched: non-functional fixes 2008-10-09 08:56:03 +02:00
elevator.c drop vmerge accounting 2008-10-09 08:56:03 +02:00
genhd.c block: fix disk->part[] dereferencing race 2008-10-09 08:56:06 +02:00
ioctl.c block: fix disk->part[] dereferencing race 2008-10-09 08:56:06 +02:00
Kconfig block: Block layer data integrity support 2008-07-03 13:21:13 +02:00
Kconfig.iosched
Makefile allow userspace to modify scsi command filter on per device basis 2008-07-03 13:21:14 +02:00
noop-iosched.c
scsi_ioctl.c SG_IO block filter whitelist missing MMC SET READ AHEAD command 2008-10-09 08:56:00 +02:00