linux/block
Jan Kara 384d87ef2c block: Do not discard buffers under a mounted filesystem
Discarding blocks and buffers under a mounted filesystem is hardly
anything admin wants to do. Usually it will confuse the filesystem and
sometimes the loss of buffer_head state (including b_private field) can
even cause crashes like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 0 P4D 0
Oops: 0002 [#1] SMP PTI
CPU: 4 PID: 203778 Comm: jbd2/dm-3-8 Kdump: loaded Tainted: G O     --------- -  - 4.18.0-147.5.0.5.h126.eulerosv2r9.x86_64 #1
Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015
RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2]
...
Call Trace:
 __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2]
 jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2]
 kjournald2+0xbd/0x270 [jbd2]

So if we don't have block device open with O_EXCL already, claim the
block device while we truncate buffer cache. This makes sure any
exclusive block device user (such as filesystem) cannot operate on the
device while we are discarding buffer cache.

Reported-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[axboe: fix !CONFIG_BLOCK error in truncate_bdev_range()]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-07 20:10:55 -06:00
..
partitions block: remove the disk argument to delete_partition 2020-09-01 19:38:25 -06:00
badblocks.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
bfq-cgroup.c bfq: fix blkio cgroup leakage v4 2020-08-18 07:48:08 -07:00
bfq-iosched.c blk-mq, elevator: Count requests per hctx to improve performance 2020-09-03 15:20:47 -06:00
bfq-iosched.h bfq: fix blkio cgroup leakage v4 2020-08-18 07:48:08 -07:00
bfq-wf2q.c bfq: fix blkio cgroup leakage v4 2020-08-18 07:48:08 -07:00
bio-integrity.c block: make function __bio_integrity_free() static 2020-07-02 12:38:18 -06:00
bio.c block: Fix page_is_mergeable() for compound pages 2020-08-17 19:35:53 -07:00
blk-cgroup-rwstat.c blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-cgroup-rwstat.h blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-cgroup.c blk-iocost: implement delay adjustment hysteresis 2020-09-01 19:38:32 -06:00
blk-core.c blk-mq: Record nr_active_requests per queue for when using shared sbitmap 2020-09-03 15:20:47 -06:00
blk-crypto-fallback.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
blk-crypto-internal.h block: blk-crypto-fallback for Inline Encryption 2020-05-14 09:48:03 -06:00
blk-crypto.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
blk-exec.c block: add a blk_account_io_merge_bio helper 2020-05-27 05:21:23 -06:00
blk-flush.c block: fix double account of flush request's driver tag 2020-08-11 13:53:32 -06:00
blk-integrity.c block: Make blk-integrity preclude hardware inline encryption 2020-05-14 09:48:03 -06:00
blk-ioc.c block: remove retry loop in ioc_release_fn() 2020-07-16 10:22:15 -06:00
blk-iocost.c blk-iocost: add three debug stat - cost.wait, indebt and indelay 2020-09-01 19:38:33 -06:00
blk-iolatency.c blk-iolatency: only call ktime_get() if needed 2020-07-01 08:02:38 -06:00
blk-lib.c block: check queue's limits.discard_granularity in __blkdev_issue_discard() 2020-08-05 17:15:47 -06:00
blk-map.c block: remove the BIO_USER_MAPPED flag 2020-09-01 16:49:26 -06:00
blk-merge.c block: Remove a duplicative condition 2020-09-01 19:48:06 -06:00
blk-mq-cpumap.c blk-mq: balance mapping between present CPUs and queues 2019-08-04 21:43:12 -06:00
blk-mq-debugfs-zoned.c block: Cleanup license notice 2019-01-17 21:21:40 -07:00
blk-mq-debugfs.c blk-mq: Use pointers for blk_mq_tags bitmap tags 2020-09-03 15:20:47 -06:00
blk-mq-debugfs.h blk-mq: no need to check return value of debugfs_create functions 2019-06-13 03:00:30 -06:00
blk-mq-pci.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-rdma.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-sched.c blk-mq: Facilitate a shared sbitmap per tagset 2020-09-03 15:20:47 -06:00
blk-mq-sched.h block: blk-mq: Remove blk_mq_sched_started_request and started_request 2019-07-23 07:25:09 -06:00
blk-mq-sysfs.c blk-mq: make sure that line break can be printed 2019-11-04 07:14:10 -07:00
blk-mq-tag.c blk-mq: Record active_queues_shared_sbitmap per tag_set for when using shared sbitmap 2020-09-03 15:20:47 -06:00
blk-mq-tag.h blk-mq: Relocate hctx_may_queue() 2020-09-03 15:20:47 -06:00
blk-mq-virtio.c blk-mq: Fix typo in comment 2020-03-17 20:55:21 +01:00
blk-mq.c blk-mq, elevator: Count requests per hctx to improve performance 2020-09-03 15:20:47 -06:00
blk-mq.h blk-mq: Record active_queues_shared_sbitmap per tag_set for when using shared sbitmap 2020-09-03 15:20:47 -06:00
blk-pm.c scsi: block: pm: Simplify resume handling 2020-07-24 22:09:55 -04:00
blk-pm.h block: remove the queue_lock indirection 2018-11-15 12:17:28 -07:00
blk-rq-qos.c Revert "blk-rq-qos: remove redundant finish_wait to rq_qos_wait." 2020-07-15 09:33:37 -06:00
blk-rq-qos.h blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -06:00
blk-settings.c block: remove blk_queue_stack_limits 2020-07-20 15:38:52 -06:00
blk-stat.c blk-stat: make q->stats->lock irqsafe 2020-09-01 16:48:46 -06:00
blk-stat.h block: deactivate blk_stat timer in wbt_disable_default() 2018-12-12 06:47:51 -07:00
blk-sysfs.c block: add max_active_zones to blk-sysfs 2020-07-15 14:26:11 -06:00
blk-throttle.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
blk-timeout.c block: blk-timeout: delete duplicated word 2020-07-31 16:29:47 -06:00
blk-wbt.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
blk-wbt.h blk-wbt: remove wbt_update_limits 2020-05-29 16:30:39 -06:00
blk-zoned.c block: don't do revalidate zones on invalid devices 2020-08-03 09:24:04 -06:00
blk.h block: remove the disk argument to delete_partition 2020-09-01 19:38:25 -06:00
bounce.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
bsg-lib.c bsg-lib: convert comma to semicolon 2020-08-16 20:07:12 -07:00
bsg.c compat_ioctl: bsg: add handler 2020-01-03 09:33:21 +01:00
cmdline-parser.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
elevator.c block: elevator: delete duplicated word and fix typos 2020-07-31 16:29:47 -06:00
genhd.c block: use revalidate_disk_size in set_capacity_revalidate_and_notify 2020-09-02 08:00:07 -06:00
ioctl.c block: Do not discard buffers under a mounted filesystem 2020-09-07 20:10:55 -06:00
ioprio.c block: grant IOPRIO_CLASS_RT to CAP_SYS_NICE 2020-09-01 19:38:33 -06:00
Kconfig blk-wbt: Remove obsolete multiqueue I/O scheduling comment 2020-09-01 16:49:26 -06:00
Kconfig.iosched treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
keyslot-manager.c block/keyslot-manager: use kvfree_sensitive() 2020-06-29 13:24:05 -06:00
kyber-iosched.c blk-mq: Use pointers for blk_mq_tags bitmap tags 2020-09-03 15:20:47 -06:00
Makefile blk-mq: merge blk-softirq.c into blk-mq.c 2020-06-24 09:15:56 -06:00
mq-deadline.c blk-mq, elevator: Count requests per hctx to improve performance 2020-09-03 15:20:47 -06:00
opal_proto.h block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
scsi_ioctl.c scsi: core: Allow non-root users to perform ZBC commands 2020-03-16 18:26:31 -04:00
sed-opal.c block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
t10-pi.c block: Allow t10-pi to be modular 2020-01-06 20:59:04 -07:00