aboutsummaryrefslogtreecommitdiff
path: root/drivers/md
AgeCommit message (Collapse)Author
2012-12-10md/raid1{,0}: fix deadlock in bitmap_unplug.NeilBrown
commit 874807a83139abc094f939e93623c5623573d543 upstream. If the raid1 or raid10 unplug function gets called from a make_request function (which is very possible) when there are bios on the current->bio_list list, then it will not be able to successfully call bitmap_unplug() and it could need to submit more bios and wait for them to complete. But they won't complete while current->bio_list is non-empty. So detect that case and handle the unplugging off to another thread just like we already do when called from within the scheduler. RAID1 version of bug was introduced in 3.6, so that part of fix is suitable for 3.6.y. RAID10 part won't apply. Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Reported-by: Peter Maloney <peter.maloney@brockmann-consult.de> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-03md/raid10: close race that lose writes lost when replacement completes.NeilBrown
commit e7c0c3fa29280d62aa5e11101a674bb3064bd791 upstream. When a replacement operation completes there is a small window when the original device is marked 'faulty' and the replacement still looks like a replacement. The faulty should be removed and the replacement moved in place very quickly, bit it isn't instant. So the code write out to the array must handle the possibility that the only working device for some slot in the replacement - but it doesn't. If the primary device is faulty it just gives up. This can lead to corruption. So make the code more robust: if either the primary or the replacement is present and working, write to them. Only when neither are present do we give up. This bug has been present since replacement was introduced in 3.3, so it is suitable for any -stable kernel since then. Reported-by: "George Spelvin" <linux@horizon.com> Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-03dm: fix deadlock with request based dm and queue request_fn recursionJens Axboe
commit a8c32a5c98943d370ea606a2e7dc04717eb92206 upstream. Request based dm attempts to re-run the request queue off the request completion path. If used with a driver that potentially does end_io from its request_fn, we could deadlock trying to recurse back into request dispatch. Fix this by punting the request queue run to kblockd. Tested to fix a quickly reproducible deadlock in such a scenario. Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-03md/raid10: decrement correct pending counter when writing to replacement.NeilBrown
commit 884162df2aadd7414bef4935e1a54976fd4e3988 upstream. When a write to a replacement device completes, we carefully and correctly found the rdev that the write actually went to and the blithely called rdev_dec_pending on the primary rdev, even if this write was to the replacement. This means that any writes to an array while a replacement was ongoing would cause the nr_pending count for the primary device to go negative, so it could never be removed. This bug has been present since replacement was introduced in 3.3, so it is suitable for any -stable kernel since then. Reported-by: "George Spelvin" <linux@horizon.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-03md: Avoid write invalid address if read_seqretry returned true.majianpeng
commit 35f9ac2dcec8f79d7059ce174fd7b7ee3290d620 upstream. If read_seqretry returned true and bbp was changed, it will write invalid address which can cause some serious problem. This bug was introduced by commit v3.0-rc7-130-g2699b67. So fix is suitable for 3.0.y thru 3.6.y. Reported-by: zhuwenfeng@kedacom.com Tested-by: zhuwenfeng@kedacom.com Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-03md: Reassigned the parameters if read_seqretry returned true in func ↵majianpeng
md_is_badblock. commit ab05613a0646dcc11049692d54bae76ca9ffa910 upstream. This bug was introduced by commit(v3.0-rc7-126-g2230dfe). So fix is suitable for 3.0.y thru 3.6.y. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-05md/raid1: Fix assembling of arrays containing Replacements.NeilBrown
commit 02b898f2f04e418094f0093a3ad0b415bcdbe8eb upstream. setup_conf in raid1.c uses conf->raid_disks before assigning a value. It is used when including 'Replacement' devices. The consequence is that assembling an array which contains a replacement will misbehave and either not include the replacement, or not include the device being replaced. Though this doesn't lead directly to data corruption, it could lead to reduced data safety. So use mddev->raid_disks, which is initialised, instead. Bug was introduced by commit c19d57980b38a5bb613a898937a1cf85f422fb9b md/raid1: recognise replacements when assembling arrays. in 3.3, so fix is suitable for 3.3.y thru 3.6.y. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21md/raid10: use correct limit variableDan Carpenter
commit 91502f099dfc5a1e8812898e26ee280713e1d002 upstream. Clang complains that we are assigning a variable to itself. This should be using bad_sectors like the similar earlier check does. Bug has been present since 3.1-rc1. It is minor but could conceivably cause corruption or other bad behaviour. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-28Merge tag 'dm-3.6-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm Pull dm fixes from Alasdair G Kergon: "A few fixes for problems discovered during the 3.6 cycle. Of particular note, are fixes to the thin target's discard support, which I hope is finally working correctly; and fixes for multipath ioctls and device limits when there are no paths." * tag 'dm-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: dm verity: fix overflow check dm thin: fix discard support for data devices dm thin: tidy discard support dm: retain table limits when swapping to new table with no devices dm table: clear add_random unless all devices have it set dm: handle requests beyond end of device instead of using BUG_ON dm mpath: only retry ioctl when no paths if queue_if_no_path set dm thin: do not set discard_zeroes_data
2012-09-27md/raid10: fix "enough" function for detecting if array is failed.NeilBrown
The 'enough' function is written to work with 'near' arrays only in that is implicitly assumes that the offset from one 'group' of devices to the next is the same as the number of copies. In reality it is the number of 'near' copies. So change it to make this number explicit. This bug makes it possible to run arrays without enough drives present, which is dangerous. It is appropriate for an -stable kernel, but will almost certainly need to be modified for some of them. Cc: stable@vger.kernel.org Reported-by: Jakub Husák <jakub@gooseman.cz> Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-26dm verity: fix overflow checkMikulas Patocka
This patch fixes sector_t overflow checking in dm-verity. Without this patch, the code checks for overflow only if sector_t is smaller than long long, not if sector_t and long long have the same size. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26dm thin: fix discard support for data devicesMike Snitzer
The discard limits that get established for a thin-pool or thin device may be incompatible with the pool's data device. Avoid this by checking the discard limits of the pool's data device. If an incompatibility is found then the pool's 'discard passdown' feature is disabled. Change thin_io_hints to ensure that a thin device always uses the same queue limits as its pool device. Introduce requested_pf to track whether or not the table line originally contained the no_discard_passdown flag and use this directly for table output. We prepare the correct setting for discard_passdown directly in bind_control_target (called from pool_io_hints) and store it in adjusted_pf rather than waiting until we have access to pool->pf in pool_preresume. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26dm thin: tidy discard supportMike Snitzer
A little thin discard code refactoring to make the next patch (dm thin: fix discard support for data devices) more readable. Pull out a couple of functions (and uses bools instead of unsigned for features). No functional changes. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26dm: retain table limits when swapping to new table with no devicesMike Snitzer
Add a safety net that will re-use the DM device's existing limits in the event that DM device has a temporary table that doesn't have any component devices. This is to reduce the chance that requests not respecting the hardware limits will reach the device. DM recalculates queue limits based only on devices which currently exist in the table. This creates a problem in the event all devices are temporarily removed such as all paths being lost in multipath. DM will reset the limits to the maximum permissible, which can then assemble requests which exceed the limits of the paths when the paths are restored. The request will fail the blk_rq_check_limits() test when sent to a path with lower limits, and will be retried without end by multipath. This became a much bigger issue after v3.6 commit fe86cdcef ("block: do not artificially constrain max_sectors for stacking drivers"). Reported-by: David Jeffery <djeffery@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26dm table: clear add_random unless all devices have it setMilan Broz
Always clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not have it set. Otherwise devices with predictable characteristics may contribute entropy. QUEUE_FLAG_ADD_RANDOM specifies whether or not queue IO timings contribute to the random pool. For bio-based targets this flag is always 0 because such devices have no real queue. For request-based devices this flag was always set to 1 by default. Now set it according to the flags on underlying devices. If there is at least one device which should not contribute, set the flag to zero: If a device, such as fast SSD storage, is not suitable for supplying entropy, a request-based queue stacked over it will not be either. Because the checking logic is exactly same as for the rotational flag, share the iteration function with device_is_nonrot(). Signed-off-by: Milan Broz <mbroz@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26dm: handle requests beyond end of device instead of using BUG_ONMike Snitzer
The access beyond the end of device BUG_ON that was introduced to dm_request_fn via commit 29e4013de7ad950280e4b2208 ("dm: implement REQ_FLUSH/FUA support for request-based dm") was an overly drastic (but simple) response to this situation. I have received a report that this BUG_ON was hit and now think it would be better to use dm_kill_unmapped_request() to fail the clone and original request with -EIO. map_request() will assign the valid target returned by dm_table_find_target to tio->ti. But when the target isn't valid tio->ti is never assigned (because map_request isn't called); so add a check for tio->ti != NULL to dm_done(). Reported-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # v2.6.37+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26dm mpath: only retry ioctl when no paths if queue_if_no_path setMike Snitzer
When there are no paths and multipath receives an ioctl, it waits until a path becomes available. This behaviour is incorrect if the "queue_if_no_path" setting was not specified, as then the ioctl should be rejected immediately, which this patch now does. commit 35991652b ("dm mpath: allow ioctls to trigger pg init") should have checked if queue_if_no_path was configured before queueing IO. Checking for the queue_if_no_path feature, like is done in map_io(), allows the following table load to work without blocking in the multipath_ioctl retry loop: echo "0 1024 multipath 0 0 0 0" | dmsetup create mpath_nodevs Without this fix the multipath_ioctl will block with the following stack trace: blkid D 0000000000000002 0 23936 1 0x00000000 ffff8802b89e5cd8 0000000000000082 ffff8802b89e5fd8 0000000000012440 ffff8802b89e4010 0000000000012440 0000000000012440 0000000000012440 ffff8802b89e5fd8 0000000000012440 ffff88030c2aab30 ffff880325794040 Call Trace: [<ffffffff814ce099>] schedule+0x29/0x70 [<ffffffff814cc312>] schedule_timeout+0x182/0x2e0 [<ffffffff8104dee0>] ? lock_timer_base+0x70/0x70 [<ffffffff814cc48e>] schedule_timeout_uninterruptible+0x1e/0x20 [<ffffffff8104f840>] msleep+0x20/0x30 [<ffffffffa0000839>] multipath_ioctl+0x109/0x170 [dm_multipath] [<ffffffffa06bfb9c>] dm_blk_ioctl+0xbc/0xd0 [dm_mod] [<ffffffff8122a408>] __blkdev_driver_ioctl+0x28/0x30 [<ffffffff8122a79e>] blkdev_ioctl+0xce/0x730 [<ffffffff811970ac>] block_ioctl+0x3c/0x40 [<ffffffff8117321c>] do_vfs_ioctl+0x8c/0x340 [<ffffffff81166293>] ? sys_newfstat+0x33/0x40 [<ffffffff81173571>] sys_ioctl+0xa1/0xb0 [<ffffffff814d70a9>] system_call_fastpath+0x16/0x1b Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.5+ Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26dm thin: do not set discard_zeroes_dataMike Snitzer
The dm thin pool target claims to support the zeroing of discarded data areas. This turns out to be incorrect when processing discards that do not exactly cover a complete number of blocks, so the target must always set discard_zeroes_data_unsupported. The thin pool target will zero blocks when they are allocated if the skip_block_zeroing feature is not specified. The block layer may send a discard that only partly covers a block. If a thin pool block is partially discarded then there is no guarantee that the discarded data will get zeroed before it is accessed again. Due to this, thin devices cannot claim discards will always zero data. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org # 3.4+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-24md/raid5: add missing spin_lock_init.NeilBrown
commit b17459c05000fdbe8d10946570a26510f86ec0f raid5: add a per-stripe lock added a spin_lock to the 'stripe_head' struct. Unfortunately there are two places where this struct is allocated but the spin lock was only initialised in one of them. So add the missing spin_lock_init. Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19md: make sure metadata is updated when spares are activated or removed.NeilBrown
It isn't always necessary to update the metadata when spares are removed as the presence-or-not of a spare isn't really important to the integrity of an array. Also activating a spare doesn't always require updating the metadata as the update on 'recovery-completed' is usually sufficient. However the introduction of 'replacement' devices have made these transitions sometimes more important. For example the 'Replacement' flag isn't cleared until the original device is removed, so we need to ensure a metadata update after that 'spare' is removed. So set MD_CHANGE_DEVS whenever a spare is activated or removed, to complement the current situation where it is set when a spare is added or a device is failed (or a number of other less common situations). This is suitable for -stable as out-of-data metadata could lead to data corruption. This is only relevant for 3.3 and later 9when 'replacement' as introduced. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19md/raid5: fix calculate of 'degraded' when a replacement becomes active.NeilBrown
When a replacement device becomes active, we mark the device that it replaces as 'faulty' so that it can subsequently get removed. However 'calc_degraded' only pays attention to the primary device, not the replacement, so the array appears to become degraded, which is wrong. So teach 'calc_degraded' to consider any replacement if a primary device is faulty. This is suitable for -stable as an incorrect 'degraded' value can confuse md and could lead to data corruption. This is only relevant for 3.3 and later. Cc: stable@vger.kernel.org Reported-by: Robin Hill <robin@robinhill.me.uk> Reported-by: John Drescher <drescherjm@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19Revert "md/raid5: For odirect-write performance, do not set ↵NeilBrown
STRIPE_PREREAD_ACTIVE." This reverts commit 895e3c5c58a80bb9e4e05d9ac38b4f30e0f97d80. While this patch seemed like a good idea and did help some workloads, it hurts other workloads. Large sequential O_DIRECT writes were faster, Small random O_DIRECT writes were slower. Other changes (batching RAID5 writes) have improved the sequential writes using a different mechanism, so the net result of this patch is definitely negative. So revert it. Reported-by: Shaohua Li <shli@kernel.org> Tested-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-18md/raid10: fix problem with on-stack allocation of r10bio structure.NeilBrown
A 'struct r10bio' has an array of per-copy information at the end. This array is declared with size [0] and r10bio_pool_alloc allocates enough extra space to store the per-copy information depending on the number of copies needed. So declaring a 'struct r10bio on the stack isn't going to work. It won't allocate enough space, and memory corruption will ensue. So in the two places where this is done, declare a sufficiently large structure and use that instead. The two call-sites of this bug were introduced in 3.4 and 3.5 so this is suitable for both those kernels. The patch will have to be modified for 3.4 as it only has one bug. Cc: stable@vger.kernel.org Reported-by: Ivan Vasilyev <ivan.vasilyev@gmail.com> Tested-by: Ivan Vasilyev <ivan.vasilyev@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-16md: Don't truncate size at 4TB for RAID0 and LinearNeilBrown
commit 27a7b260f71439c40546b43588448faac01adb93 md: Fix handling for devices from 2TB to 4TB in 0.90 metadata. changed 0.90 metadata handling to truncated size to 4TB as that is all that 0.90 can record. However for RAID0 and Linear, 0.90 doesn't need to record the size, so this truncation is not needed and causes working arrays to become too small. So avoid the truncation for RAID0 and Linear This bug was introduced in 3.1 and is suitable for any stable kernels from then onwards. As the offending commit was tagged for 'stable', any stable kernel that it was applied to should also get this patch. That includes at least 2.6.32, 2.6.33 and 3.0. (Thanks to Ben Hutchings for providing that list). Cc: stable@vger.kernel.org Signed-off-by: Neil Brown <neilb@suse.de>
2012-08-02Merge tag 'md-3.6' of git://neil.brown.name/mdLinus Torvalds
Pull additional md update from NeilBrown: "This contains a few patches that depend on plugging changes in the block layer so needed to wait for those. It also contains a Kconfig fix for the new RAID10 support in dm-raid." * tag 'md-3.6' of git://neil.brown.name/md: md/dm-raid: DM_RAID should select MD_RAID10 md/raid1: submit IO from originating thread instead of md thread. raid5: raid5d handle stripe in batch way raid5: make_request use batch stripe release
2012-08-02md/dm-raid: DM_RAID should select MD_RAID10NeilBrown
Now that DM_RAID supports raid10, it needs to select that code to ensure it is included. Cc: Jonathan Brassow <jbrassow@redhat.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02md/raid1: submit IO from originating thread instead of md thread.NeilBrown
queuing writes to the md thread means that all requests go through the one processor which may not be able to keep up with very high request rates. So use the plugging infrastructure to submit all requests on unplug. If a 'schedule' is needed, we fall back on the old approach of handing the requests to the thread for it to handle. Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02raid5: raid5d handle stripe in batch wayShaohua Li
Let raid5d handle stripe in batch way to reduce conf->device_lock locking. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02raid5: make_request use batch stripe releaseShaohua Li
make_request() does stripe release for every stripe and the stripe usually has count 1, which makes previous release_stripe() optimization not work. In my test, this release_stripe() becomes the heaviest pleace to take conf->device_lock after previous patches applied. Below patch makes stripe release batch. All the stripes will be released in unplug. The STRIPE_ON_UNPLUG_LIST bit is to protect concurrent access stripe lru. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-01Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver changes from Jens Axboe: - Making the plugging support for drivers a bit more sane from Neil. This supersedes the plugging change from Shaohua as well. - The usual round of drbd updates. - Using a tail add instead of a head add in the request completion for ndb, making us find the most completed request more quickly. - A few floppy changes, getting rid of a duplicated flag and also running the floppy init async (since it takes forever in boot terms) from Andi. * 'for-3.6/drivers' of git://git.kernel.dk/linux-block: floppy: remove duplicated flag FD_RAW_NEED_DISK blk: pass from_schedule to non-request unplug functions. block: stack unplug blk: centralize non-request unplug handling. md: remove plug_cnt feature of plugging. block/nbd: micro-optimization in nbd request completion drbd: announce FLUSH/FUA capability to upper layers drbd: fix max_bio_size to be unsigned drbd: flush drbd work queue before invalidate/invalidate remote drbd: fix potential access after free drbd: call local-io-error handler early drbd: do not reset rs_pending_cnt too early drbd: reset congestion information before reporting it in /proc/drbd drbd: report congestion if we are waiting for some userland callback drbd: differentiate between normal and forced detach drbd: cleanup, remove two unused global flags floppy: Run floppy initialization asynchronous
2012-08-01Merge branch 'for-next' of git://neil.brown.name/mdLinus Torvalds
Pull md updates from NeilBrown. * 'for-next' of git://neil.brown.name/md: DM RAID: Add support for MD RAID10 md/RAID1: Add missing case for attempting to repair known bad blocks. md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE. md/raid1: don't abort a resync on the first badblock. md: remove duplicated test on ->openers when calling do_md_stop() raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer md/raid1: prevent merging too large request md/raid1: read balance chooses idlest disk for SSD md/raid1: make sequential read detection per disk based MD RAID10: Export md_raid10_congested MD: Move macros from raid1*.h to raid1*.c MD RAID1: rename mirror_info structure MD RAID10: rename mirror_info structure MD RAID10: Fix compiler warning. raid5: add a per-stripe lock raid5: remove unnecessary bitmap write optimization raid5: lockless access raid5 overrided bi_phys_segments raid5: reduce chance release_stripe() taking device_lock
2012-08-01DM RAID: Add support for MD RAID10Jonathan Brassow
Support the MD RAID10 personality through dm-raid.c Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-01Merge commit 'c039c332f23e794deb6d6f37b9f07ff3b27fb2cf' into mdNeilBrown
Pull in pre-requisites for adding raid10 support to dm-raid.
2012-07-31blk: pass from_schedule to non-request unplug functions.NeilBrown
This will allow md/raid to know why the unplug was called, and will be able to act according - if !from_schedule it is safe to perform tasks which could themselves schedule. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31blk: centralize non-request unplug handling.NeilBrown
Both md and umem has similar code for getting notified on an blk_finish_plug event. Centralize this code in block/ and allow each driver to provide its distinctive difference. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31md: remove plug_cnt feature of plugging.NeilBrown
This seemed like a good idea at the time, but after further thought I cannot see it making a difference other than very occasionally and testing to try to exercise the case it is most likely to help did not show any performance difference by removing it. So remove the counting of active plugs and allow 'pending writes' to be activated at any time, not just when no plugs are active. This is only relevant when there is a write-intent bitmap, and the updating of the bitmap will likely introduce enough delay that the single-threading of bitmap updates will be enough to collect large numbers of updates together. Removing this will make it easier to centralise the unplug code, and will clear the other for other unplug enhancements which have a measurable effect. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31md/RAID1: Add missing case for attempting to repair known bad blocks.Alexander Lyakas
When doing resync or repair, attempt to correct bad blocks, according to WriteErrorSeen policy Signed-off-by: Alex Lyakas <alex.bolshoy@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-30Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
Merge Andrew's first set of patches: "Non-MM patches: - lots of misc bits - tree-wide have_clk() cleanups - quite a lot of printk tweaks. I draw your attention to "printk: convert the format for KERN_<LEVEL> to a 2 byte pattern" which looks a bit scary. But afaict it's solid. - backlight updates - lib/ feature work (notably the addition and use of memweight()) - checkpatch updates - rtc updates - nilfs updates - fatfs updates (partial, still waiting for acks) - kdump, proc, fork, IPC, sysctl, taskstats, pps, etc - new fault-injection feature work" * Merge emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits) drivers/misc/lkdtm.c: fix missing allocation failure check lib/scatterlist: do not re-write gfp_flags in __sg_alloc_table() fault-injection: add tool to run command with failslab or fail_page_alloc fault-injection: add selftests for cpu and memory hotplug powerpc: pSeries reconfig notifier error injection module memory: memory notifier error injection module PM: PM notifier error injection module cpu: rewrite cpu-notifier-error-inject module fault-injection: notifier error injection c/r: fcntl: add F_GETOWNER_UIDS option resource: make sure requested range is included in the root range include/linux/aio.h: cpp->C conversions fs: cachefiles: add support for large files in filesystem caching pps: return PTR_ERR on error in device_create taskstats: check nla_reserve() return sysctl: suppress kmemleak messages ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION ipc: compat: use signed size_t types for msgsnd and msgrcv ipc: allow compat IPC version field parsing if !ARCH_WANT_OLD_COMPAT_IPC ipc: add COMPAT_SHMLBA support ...
2012-07-30dm: use memweight()Akinobu Mita
Use memweight() to count the total number of bits set in memory area. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE.majianpeng
'sync' writes set both REQ_SYNC and REQ_NOIDLE. O_DIRECT writes set REQ_SYNC but not REQ_NOIDLE. We currently assume that a REQ_SYNC request will not be followed by more requests and so set STRIPE_PREREAD_ACTIVE to expedite the request. This is appropriate for sync requests, but not for O_DIRECT requests. So make the setting of STRIPE_PREREAD_ACTIVE conditional on REQ_NOIDLE rather than REQ_SYNC. This is consistent with the documented meaning of REQ_NOIDLE: __REQ_NOIDLE, /* don't anticipate more IO after this one */ Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31md/raid1: don't abort a resync on the first badblock.NeilBrown
If a resync of a RAID1 array with 2 devices finds a known bad block one device it will neither read from, or write to, that device for this block offset. So there will be one read_target (The other device) and zero write targets. This condition causes md/raid1 to abort the resync assuming that it has finished - without known bad blocks this would be true. When there are no write targets because of the presence of bad blocks we should only skip over the area covered by the bad block. RAID10 already gets this right, raid1 doesn't. Or didn't. As this can cause a 'sync' to abort early and appear to have succeeded it could lead to some data corruption, so it suitable for -stable. Cc: stable@vger.kernel.org Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31md: remove duplicated test on ->openers when calling do_md_stop()NeilBrown
do_md_stop tests mddev->openers while holding ->open_mutex, and fails if this count is too high. So callers do not need to check mddev->openers and doing so isn't very meaningful as they don't hold ->open_mutex so the number could change. So remove the unnecessary tests on mddev->openers. These are not called often enough for there to be any gain in an early test on ->open_mutex to avoid the need for a slightly more costly mutex_lock call. Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layermajianpeng
Because bios will merge at block-layer,so bios-error may caused by other bio which be merged into to the same request. Using this flag,it will find exactly error-sector and not do redundant operation like re-write and re-read. V0->V1:Using REQ_FLUSH instead REQ_NOMERGE avoid bio merging at block layer. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31md/raid1: prevent merging too large requestShaohua Li
For SSD, if request size exceeds specific value (optimal io size), request size isn't important for bandwidth. In such condition, if making request size bigger will cause some disks idle, the total throughput will actually drop. A good example is doing a readahead in a two-disk raid1 setup. So when should we split big requests? We absolutly don't want to split big request to very small requests. Even in SSD, big request transfer is more efficient. This patch only considers request with size above optimal io size. If all disks are busy, is it worth doing a split? Say optimal io size is 16k, two requests 32k and two disks. We can let each disk run one 32k request, or split the requests to 4 16k requests and each disk runs two. It's hard to say which case is better, depending on hardware. So only consider case where there are idle disks. For readahead, split is always better in this case. And in my test, below patch can improve > 30% thoughput. Hmm, not 100%, because disk isn't 100% busy. Such case can happen not just in readahead, for example, in directio. But I suppose directio usually will have bigger IO depth and make all disks busy, so I ignored it. Note: if the raid uses any hard disk, we don't prevent merging. That will make performace worse. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31md/raid1: read balance chooses idlest disk for SSDShaohua Li
SSD hasn't spindle, distance between requests means nothing. And the original distance based algorithm sometimes can cause severe performance issue for SSD raid. Considering two thread groups, one accesses file A, the other access file B. The first group will access one disk and the second will access the other disk, because requests are near from one group and far between groups. In this case, read balance might keep one disk very busy but the other relative idle. For SSD, we should try best to distribute requests to as many disks as possible. There isn't spindle move penality anyway. With below patch, I can see more than 50% throughput improvement sometimes depending on workloads. The only exception is small requests can be merged to a big request which typically can drive higher throughput for SSD too. Such small requests are sequential reads. Unlike hard disk, sequential read which can't be merged (for example direct IO, or read without readahead) can be ignored for SSD. Again there is no spindle move penality. readahead dispatches small requests and such requests can be merged. Last patch can help detect sequential read well, at least if concurrent read number isn't greater than raid disk number. In that case, distance based algorithm doesn't work well too. V2: For hard disk and SSD mixed raid, doesn't use distance based algorithm for random IO too. This makes the algorithm generic for raid with SSD. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31md/raid1: make sequential read detection per disk basedShaohua Li
Currently the sequential read detection is global wide. It's natural to make it per disk based, which can improve the detection for concurrent multiple sequential reads. And next patch will make SSD read balance not use distance based algorithm, where this change help detect truly sequential read for SSD. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31MD RAID10: Export md_raid10_congestedJonathan Brassow
md/raid10: Export is_congested test. In similar fashion to commits 11d8a6e3719519fbc0e2c9d61b6fa931b84bf813 1ed7242e591af7e233234d483f12d33818b189d9 we export the RAID10 congestion checking function so that dm-raid.c can make use of it and make use of the personality. The 'queue' and 'gendisk' structures will not be available to the MD code when device-mapper sets up the device, so we conditionalize access to these fields also. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31MD: Move macros from raid1*.h to raid1*.cJonathan Brassow
MD RAID1/RAID10: Move some macros from .h file to .c file There are three macros (IO_BLOCKED,IO_MADE_GOOD,BIO_SPECIAL) which are defined in both raid1.h and raid10.h. They are only used in there respective .c files. However, if we wish to make RAID10 accessible to the device-mapper RAID target (dm-raid.c), then we need to move these macros into the .c files where they are used so that they do not conflict with each other. The macros from the two files are identical and could be moved into md.h, but I chose to leave the duplication and have them remain in the personality files. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31MD RAID1: rename mirror_info structureJonathan Brassow
MD RAID1: Rename the structure 'mirror_info' to 'raid1_info' The same structure name ('mirror_info') is used by raid10. Each of these structures are defined in there respective header files. If dm-raid is to support both RAID1 and RAID10, the header files will be included and the structure names must not collide. While only one of these structure names needs to change, this patch adds consistency to the naming of the structure. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31MD RAID10: rename mirror_info structureJonathan Brassow
MD RAID10: Rename the structure 'mirror_info' to 'raid10_info' The same structure name ('mirror_info') is used by raid1. Each of these structures are defined in there respective header files. If dm-raid is to support both RAID1 and RAID10, the header files will be included and the structure names must not collide. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>