Mike Snitzer 586b286b11 dm crypt: constrain crypt device's max_segment_size to PAGE_SIZE ... Setting the dm-crypt device's max_segment_size to PAGE_SIZE is an unfortunate constraint that is required to avoid the potential for exceeding dm-crypt's underlying device's max_segments limits -- due to crypt_alloc_buffer() possibly allocating pages for the encryption bio that are not as physically contiguous as the original bio. It is interesting to note that this problem was already fixed back in 2007 via commit 91e106259 ("dm crypt: use bio_add_page"). But Linux 4.0 commit cf2f1abfb ("dm crypt: don't allocate pages for a partial request") regressed dm-crypt back to _not_ using bio_add_page(). But given dm-crypt's cpu parallelization changes all depend on commit cf2f1abfb's abandoning of the more complex io fragments processing that dm-crypt previously had we cannot easily go back to using bio_add_page(). So all said the cleanest way to resolve this issue is to fix dm-crypt to properly constrain the original bios entering dm-crypt so the encryption bios that dm-crypt generates from the original bios are always compatible with the underlying device's max_segments queue limits. It should be noted that technically Linux 4.3 does _not_ need this fix because of the block core's new late bio-splitting capability. But, it is reasoned, there is little to be gained by having the block core split the encrypted bio that is composed of PAGE_SIZE segments. That said, in the future we may revert this change. Fixes: cf2f1abfb ("dm crypt: don't allocate pages for a partial request") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=104421 Suggested-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.0+		2015-09-14 12:04:24 -04:00
..
bcache	bcache: remove driver private bio splitting code	2015-08-13 12:31:40 -06:00
persistent-data	dm: remove unlikely() before IS_ERR()	2015-08-12 11:32:21 -04:00
bitmap.c	Some md fixes for 4.2	2015-07-25 11:24:58 -07:00
bitmap.h	md-cluster: re-add capabilities	2015-04-22 07:59:39 +10:00
dm-bio-prison.c	block: add a bi_error field to struct bio	2015-07-29 08:55:15 -06:00
dm-bio-prison.h	dm bio prison: add dm_cell_promote_or_release()	2015-05-29 14:19:06 -04:00
dm-bio-record.h	dm: Refactor for new bio cloning/splitting	2013-11-23 22:33:55 -08:00
dm-bufio.c	block: add a bi_error field to struct bio	2015-07-29 08:55:15 -06:00
dm-bufio.h	dm snapshot: use dm-bufio prefetch	2014-01-14 23:23:03 -05:00
dm-builtin.c	dm sysfs: fix a module unload race	2014-01-14 23:23:04 -05:00
dm-cache-block-types.h	dm cache: revert "remove remainder of distinct discard block size"	2014-11-10 15:25:30 -05:00
dm-cache-metadata.c	dm cache: add fail io mode and needs_check flag	2015-06-11 17:13:00 -04:00
dm-cache-metadata.h	dm cache: add fail io mode and needs_check flag	2015-06-11 17:13:00 -04:00
dm-cache-policy-cleaner.c	dm cache: pass a new 'critical' flag to the policies when requesting writeback work	2015-05-29 14:19:04 -04:00
dm-cache-policy-internal.h	dm cache: age and write back cache entries even without active IO	2015-06-11 17:13:01 -04:00
dm-cache-policy-mq.c	dm cache policy smq: move 'dm-cache-default' module alias to SMQ	2015-08-12 11:27:29 -04:00
dm-cache-policy-smq.c	dm cache policy smq: change the mutex to a spinlock	2015-08-12 11:32:19 -04:00
dm-cache-policy.c	dm cache: add policy name to status output	2014-01-16 13:44:11 -05:00
dm-cache-policy.h	dm cache: age and write back cache entries even without active IO	2015-06-11 17:13:01 -04:00
dm-cache-target.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-crypt.c	dm crypt: constrain crypt device's max_segment_size to PAGE_SIZE	2015-09-14 12:04:24 -04:00
dm-delay.c	dm: do not override error code returned from dm_get_device()	2015-08-12 11:32:21 -04:00
dm-era-target.c	block: kill merge_bvec_fn() completely	2015-08-13 12:31:57 -06:00
dm-exception-store.c
dm-exception-store.h
dm-flakey.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-io.c	block: remove bio_get_nr_vecs()	2015-08-13 12:32:04 -06:00
dm-ioctl.c	char: make misc_deregister a void function	2015-08-05 10:35:49 -07:00
dm-kcopyd.c	dm: stop using WQ_NON_REENTRANT	2013-08-23 09:02:13 -04:00
dm-linear.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-log-userspace-base.c	dm log userspace base: fix compile warning	2015-04-15 12:10:20 -04:00
dm-log-userspace-transfer.c	dm log userspace transfer: match wait_for_completion_timeout return type	2015-04-15 12:10:20 -04:00
dm-log-userspace-transfer.h
dm-log-writes.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-log.c
dm-mpath.c	dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath	2015-08-28 13:14:55 -07:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c
dm-raid1.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-raid.c	block: kill merge_bvec_fn() completely	2015-08-13 12:31:57 -06:00
dm-region-hash.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
dm-round-robin.c
dm-service-time.c
dm-snap-persistent.c	dm: remove unlikely() before IS_ERR()	2015-08-12 11:32:21 -04:00
dm-snap-transient.c
dm-snap.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-stats.c	dm stats: report precise_timestamps and histogram in @stats_list output	2015-08-18 17:20:03 -04:00
dm-stats.h	dm stats: support precise timestamps	2015-06-17 12:40:40 -04:00
dm-stripe.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-switch.c	dm switch: efficiently support repetitive patterns	2014-08-01 12:30:37 -04:00
dm-sysfs.c	dm: add 'use_blk_mq' module param and expose in per-device ro sysfs attr	2015-04-15 12:10:17 -04:00
dm-table.c	block: Replace SG_GAPS with new queue limits mask	2015-08-19 14:26:02 -07:00
dm-target.c	dm: allocate requests in target when stacking on blk-mq devices	2015-02-09 13:06:47 -05:00
dm-thin-metadata.c	dm thin metadata: delete btrees when releasing metadata snapshot	2015-08-12 10:42:51 -04:00
dm-thin-metadata.h	dm thin metadata: add dm_thin_remove_range()	2015-06-11 17:13:04 -04:00
dm-thin.c	dm thin: disable discard support for thin devices if pool's is disabled	2015-09-13 21:32:10 -04:00
dm-uevent.c
dm-uevent.h
dm-verity.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm-zero.c	block: add a bi_error field to struct bio	2015-07-29 08:55:15 -06:00
dm.c	Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm	2015-09-02 16:35:26 -07:00
dm.h	block: kill merge_bvec_fn() completely	2015-08-13 12:31:57 -06:00
faulty.c	block: add a bi_error field to struct bio	2015-07-29 08:55:15 -06:00
Kconfig	SCSI misc on 20150911	2015-09-11 18:15:18 -07:00
linear.c	block: kill merge_bvec_fn() completely	2015-08-13 12:31:57 -06:00
linear.h
Makefile	dm cache: add stochastic-multi-queue (smq) policy	2015-06-11 17:12:59 -04:00
md-cluster.c	md-cluster: remove inappropriate try_module_get from join()	2015-08-31 19:43:17 +02:00
md-cluster.h	Fix read-balancing during node failure	2015-07-24 13:37:59 +10:00
md.c	Merge linux-block/for-4.3/core into md/for-linux	2015-09-05 11:08:32 +02:00
md.h	block: kill merge_bvec_fn() completely	2015-08-13 12:31:57 -06:00
multipath.c	block: kill merge_bvec_fn() completely	2015-08-13 12:31:57 -06:00
multipath.h
raid0.c	Merge linux-block/for-4.3/core into md/for-linux	2015-09-05 11:08:32 +02:00
raid0.h	block: kill merge_bvec_fn() completely	2015-08-13 12:31:57 -06:00
raid1.c	Merge linux-block/for-4.3/core into md/for-linux	2015-09-05 11:08:32 +02:00
raid1.h	md/raid1: ensure device failure recorded before write request returns.	2015-08-31 19:43:23 +02:00
raid5.c	Merge linux-block/for-4.3/core into md/for-linux	2015-09-05 11:08:32 +02:00
raid5.h	md/raid5: ensure device failure recorded before write request returns.	2015-08-31 19:43:59 +02:00
raid10.c	Merge linux-block/for-4.3/core into md/for-linux	2015-09-05 11:08:32 +02:00
raid10.h	md/raid10: ensure device failure recorded before write request returns.	2015-08-31 19:43:45 +02:00