linux/block
Linus Torvalds a32e236eb9 Partially revert "block: fail op_is_write() requests to read-only partitions"
It turns out that commit 721c7fc701 ("block: fail op_is_write()
requests to read-only partitions"), while obviously correct, causes
problems for some older lvm2 installations.

The reason is that the lvm snapshotting will continue to write to the
snapshow COW volume, even after the volume has been marked read-only.
End result: snapshot failure.

This has actually been fixed in newer version of the lvm2 tool, but the
old tools still exist, and the breakage was reported both in the kernel
bugzilla and in the Debian bugzilla:

  https://bugzilla.kernel.org/show_bug.cgi?id=200439
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=900442

The lvm2 fix is here

  https://sourceware.org/git/?p=lvm2.git;a=commit;h=a6fdb9d9d70f51c49ad11a87ab4243344e6701a3

but until everybody has updated to recent versions, we'll have to weaken
the "never write to read-only partitions" check.  It now allows the
write to happen, but causes a warning, something like this:

  generic_make_request: Trying to write to read-only block-device dm-3 (partno X)
  Modules linked in: nf_tables xt_cgroup xt_owner kvm_intel iwlmvm kvm irqbypass iwlwifi
  CPU: 1 PID: 77 Comm: kworker/1:1 Not tainted 4.17.9-gentoo #3
  Hardware name: LENOVO 20B6A019RT/20B6A019RT, BIOS GJET91WW (2.41 ) 09/21/2016
  Workqueue: ksnaphd do_metadata
  RIP: 0010:generic_make_request_checks+0x4ac/0x600
  ...
  Call Trace:
   generic_make_request+0x64/0x400
   submit_bio+0x6c/0x140
   dispatch_io+0x287/0x430
   sync_io+0xc3/0x120
   dm_io+0x1f8/0x220
   do_metadata+0x1d/0x30
   process_one_work+0x1b9/0x3e0
   worker_thread+0x2b/0x3c0
   kthread+0x113/0x130
   ret_from_fork+0x35/0x40

Note that this is a "revert" in behavior only.  I'm leaving alone the
actual code cleanups in commit 721c7fc701, but letting the previously
uncaught request go through with a warning instead of stopping it.

Fixes: 721c7fc701 ("block: fail op_is_write() requests to read-only partitions")
Reported-and-tested-by: WGH <wgh@torlan.ru>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-04 18:19:55 -07:00
..
partitions treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
badblocks.c badblocks: fix wrong return value in badblocks_set if badblocks are disabled 2017-11-03 11:29:50 -07:00
bfq-cgroup.c block: use ktime_get_ns() instead of sched_clock() for cfq and bfq 2018-05-09 08:33:06 -06:00
bfq-iosched.c block, bfq: prevent soft_rt_next_start from being stuck at infinity 2018-05-31 08:54:41 -06:00
bfq-iosched.h block, bfq: remove slow-system class 2018-05-31 08:54:38 -06:00
bfq-wf2q.c block, bfq: limit sectors served with interactive weight raising 2018-01-18 08:21:37 -07:00
bio-integrity.c block: Convert bio_set to mempool_init() 2018-05-14 13:16:03 -06:00
bio.c for-linus-20180727 2018-07-27 12:51:00 -07:00
blk-cgroup.c blkcg: init root blkcg_gq under lock 2018-04-19 08:51:59 -06:00
blk-core.c Partially revert "block: fail op_is_write() requests to read-only partitions" 2018-08-04 18:19:55 -07:00
blk-exec.c blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request 2018-01-17 09:49:21 -07:00
blk-flush.c block: fix use-after-free in block flush handling 2018-06-09 06:37:14 -06:00
blk-integrity.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
blk-ioc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-lib.c block: break discard submissions into the user defined size 2018-05-08 15:10:44 -06:00
blk-map.c Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block 2018-01-29 11:51:49 -08:00
blk-merge.c block: don't use blocking queue entered for recursive bio submits 2018-06-02 20:35:00 -06:00
blk-mq-cpumap.c blk-mq: don't keep offline CPUs mapped to hctx 0 2018-04-10 08:38:46 -06:00
blk-mq-debugfs.c blk-mq-debugfs: Off by one in blk_mq_rq_state_name() 2018-06-20 11:26:04 -06:00
blk-mq-debugfs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-mq-pci.c blk-mq: Allow PCI vector offset for mapping queues 2018-03-27 21:25:36 -06:00
blk-mq-rdma.c block: Add rdma affinity based queue mapping helper 2017-08-08 14:58:03 -04:00
blk-mq-sched.c blk-mq: update nr_requests when switching to 'none' scheduler 2018-06-02 20:35:00 -06:00
blk-mq-sched.h block: move sysfs_lock into elevator_init 2018-06-01 07:38:19 -06:00
blk-mq-sysfs.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
blk-mq-tag.c blk-mq: fix blk_mq_tagset_busy_iter 2018-08-02 14:47:20 -06:00
blk-mq-tag.h Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block 2017-11-14 15:32:19 -08:00
blk-mq-virtio.c blk-mq: provide a default queue mapping for virtio device 2017-02-27 20:54:05 +02:00
blk-mq.c for-linus-20180727 2018-07-27 12:51:00 -07:00
blk-mq.h blk-mq: Remove generation seqeunce 2018-05-29 08:59:21 -06:00
blk-settings.c block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}() 2018-03-08 14:13:48 -07:00
blk-softirq.c block: fix timeout changes for legacy request drivers 2018-06-19 11:27:18 -06:00
blk-stat.c block: consolidate struct request timestamp fields 2018-05-09 08:33:09 -06:00
blk-stat.h block: consolidate struct request timestamp fields 2018-05-09 08:33:09 -06:00
blk-sysfs.c block: convert bounce, q->bio_split to bioset_init()/mempool_init() 2018-05-30 15:33:32 -06:00
blk-tag.c for-linus-20180616 2018-06-17 05:37:55 +09:00
blk-throttle.c blk-throttle: return proper bool type to caller instead of 0/1 2018-05-30 12:48:22 -06:00
blk-timeout.c blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE 2018-06-23 10:25:45 -06:00
blk-wbt.c block: get rid of struct blk_issue_stat 2018-05-09 08:33:05 -06:00
blk-wbt.h block: get rid of struct blk_issue_stat 2018-05-09 08:33:05 -06:00
blk-zoned.c treewide: kvmalloc() -> kvmalloc_array() 2018-06-12 16:19:22 -07:00
blk.h block: split the blk-mq case from elevator_init 2018-06-01 07:38:21 -06:00
bounce.c block: fixup bioset_integrity_create() call 2018-05-30 18:51:21 -06:00
bsg-lib.c block: remove parent device reference from struct bsg_class_device 2018-05-29 13:00:25 -06:00
bsg.c bsg: fix bogus EINVAL on non-data commands 2018-07-11 08:48:28 -06:00
cfq-iosched.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
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
compat_ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
deadline-iosched.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
elevator.c block: split the blk-mq case from elevator_init 2018-06-01 07:38:21 -06:00
genhd.c Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:00:01 -07:00
ioctl.c block: pass inclusive 'lend' parameter to truncate_inode_pages_range 2018-02-23 15:20:19 -07:00
ioprio.c block: add ioprio_check_cap function 2018-05-31 10:50:54 -04:00
Kconfig docs: Fix some broken references 2018-06-15 18:10:01 -03:00
Kconfig.iosched License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kyber-iosched.c block: kyber: make kyber more friendly with merging 2018-05-30 10:47:40 -06:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mq-deadline.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
noop-iosched.c block: move existing elevator ops to union 2017-01-17 10:03:33 -07:00
opal_proto.h block: sed-opal: Set MBRDone on S3 resume path if TPER is MBREnabled 2017-09-11 09:45:52 -06:00
partition-generic.c block: don't print a message when the device went away 2018-05-29 08:59:21 -06:00
scsi_ioctl.c block: consistently use GFP_NOIO instead of __GFP_NORECLAIM 2018-05-14 08:55:18 -06:00
sed-opal.c block: sed-opal: Fix a couple off by one bugs 2018-06-20 12:04:06 -06:00
t10-pi.c t10-pi: Move opencoded contants to common header 2017-07-03 16:56:25 -06:00