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2012-01-15Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds
* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits) Revert "block: recursive merge requests" block: Stop using macro stubs for the bio data integrity calls blockdev: convert some macros to static inlines fs: remove unneeded plug in mpage_readpages() block: Add BLKROTATIONAL ioctl block: Introduce blk_set_stacking_limits function block: remove WARN_ON_ONCE() in exit_io_context() block: an exiting task should be allowed to create io_context block: ioc_cgroup_changed() needs to be exported block: recursive merge requests block, cfq: fix empty queue crash caused by request merge block, cfq: move icq creation and rq->elv.icq association to block core block, cfq: restructure io_cq creation path for io_context interface cleanup block, cfq: move io_cq exit/release to blk-ioc.c block, cfq: move icq cache management to block core block, cfq: move io_cq lookup to blk-ioc.c block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq block, cfq: reorganize cfq_io_context into generic and cfq specific parts block: remove elevator_queue->ops block: reorder elevator switch sequence ... Fix up conflicts in: - block/blk-cgroup.c Switch from can_attach_task to can_attach - block/cfq-iosched.c conflict with now removed cic index changes (we now use q->id instead)
2012-01-14dm: do not forward ioctls from logical volumes to the underlying devicePaolo Bonzini
A logical volume can map to just part of underlying physical volume. In this case, it must be treated like a partition. Based on a patch from Alasdair G Kergon. Cc: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12Merge tag 'md-3.3-fixes' of git://neil.brown.name/mdLinus Torvalds
Two bugfixes for md. One is a recently introduced regression that affects an unusual configuration with a guaranteed BUG_ON. Has been tagged for -stable. The other is minor missing functionality. * tag 'md-3.3-fixes' of git://neil.brown.name/md: md/raid1: perform bad-block tests for WriteMostly devices too. md: notify the 'degraded' sysfs attribute on failure.
2012-01-11block: Introduce blk_set_stacking_limits functionMartin K. Petersen
Stacking driver queue limits are typically bounded exclusively by the capabilities of the low level devices, not by the stacking driver itself. This patch introduces blk_set_stacking_limits() which has more liberal metrics than the default queue limits function. This allows us to inherit topology parameters from bottom devices without manually tweaking the default limits in each driver prior to calling the stacking function. Since there is now a clear distinction between stacking and low-level devices, blk_set_default_limits() has been modified to carry the more conservative values that we used to manually set in blk_queue_make_request(). Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-01-10md/raid1: perform bad-block tests for WriteMostly devices too.NeilBrown
We normally try to avoid reading from write-mostly devices, but when we do we really have to check for bad blocks and be sure not to try reading them. With the current code, best_good_sectors might not get set and that causes zero-length read requests to be send down which is very confusing. This bug was introduced in commit d2eb35acfdccbe2 and so the patch is suitable for 3.1.x and 3.2.x Reported-and-tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Reported-and-tested-by: Art -kwaak- van Breemen <ard@telegraafnet.nl> Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@vger.kernel.org
2012-01-10md: notify the 'degraded' sysfs attribute on failure.NeilBrown
We currently only 'notify' changes to the 'degraded' attribute when it decreases, not when it increases. Notifying on failure is a little awkward as it happen in interrupt context. So instead, notify when we remove the failed device from the array, which is very soon afterwards. Reported-and-tested-by: Mikhail Balabin <mbalabin@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-01-08Merge tag 'md-3.3' of git://neil.brown.name/mdLinus Torvalds
md update for 3.3 Big change is new hot-replacement. A slot in an array can hold 2 devices - one that wants-replacement and one that is the replacement. Once the replacement is built - either from the original or (in the case of errors) from elsewhere, the wants-replacement device will be removed. * tag 'md-3.3' of git://neil.brown.name/md: (36 commits) md/raid1: Mark device want_replacement when we see a write error. md/raid1: If there is a spare and a want_replacement device, start replacement. md/raid1: recognise replacements when assembling arrays. md/raid1: handle activation of replacement device when recovery completes. md/raid1: Allow a failed replacement device to be removed. md/raid1: Allocate spare to store replacement devices and their bios. md/raid1: Replace use of mddev->raid_disks with conf->raid_disks. md/raid10: If there is a spare and a want_replacement device, start replacement. md/raid10: recognise replacements when assembling array. md/raid10: Allow replacement device to be replace old drive. md/raid10: handle recovery of replacement devices. md/raid10: Handle replacement devices during resync. md/raid10: writes should get directed to replacement as well as original. md/raid10: allow removal of failed replacement devices. md/raid10: preferentially read from replacement device if possible. md/raid10: change read_balance to return an rdev md/raid10: prepare data structures for handling replacement. md/raid5: Mark device want_replacement when we see a write error. md/raid5: If there is a spare and a want_replacement device, start replacement. md/raid5: recognise replacements when assembling array. ...
2012-01-04fs: move code out of buffer.cAl Viro
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-22md/raid1: Mark device want_replacement when we see a write error.NeilBrown
Now that WantReplacement drives are replaced cleanly, mark a drive as want_replacement when we see a write error. It might get failed soon so the WantReplacement flag is irrelevant, but if the write error is recorded in the bad block log, we still want to activate any spare that might be available. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid1: If there is a spare and a want_replacement device, start replacement.NeilBrown
When attempting to add a spare to a RAID1 array, also consider adding it as a replacement for a want_replacement device. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid1: recognise replacements when assembling arrays.NeilBrown
If a Replacement is seen, file it as such. If we see two replacements (or two normal devices) for the one slot, abort. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid1: handle activation of replacement device when recovery completes.NeilBrown
When recovery completes ->spare_active is called. This checks if the replacement is ready and if so it fails the original. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid1: Allow a failed replacement device to be removed.NeilBrown
Replacement devices are stored at a different offset, so look there too. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid1: Allocate spare to store replacement devices and their bios.NeilBrown
In RAID1, a replacement is much like a normal device, so we just double the size of the relevant arrays and look at all possible devices for reads and writes. This means that the array looks like it is now double the size in some way - we need to be careful about that. In particular, we checking if the array is still degraded while creating a recovery request we need to only consider the first 'half' - i.e. the real (non-replacement) devices. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid1: Replace use of mddev->raid_disks with conf->raid_disks.NeilBrown
In general mddev->raid_disks can change unexpectedly while conf->raid_disks will only change in a very controlled way. So change some uses of one to the other. The use of mddev->raid_disks will not cause actually problems but this way is more consistent and safer in the long term. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: If there is a spare and a want_replacement device, start replacement.NeilBrown
When attempting to add a spare to a RAID10 array, also consider adding it as a replacement for a want_replacement device. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: recognise replacements when assembling array.NeilBrown
If a Replacement is seen, file it as such. If we see two replacements (or two normal devices) for the one slot, abort. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: Allow replacement device to be replace old drive.NeilBrown
When recovery finish and spare_active is called, check for a replace that might have just become fully synced and mark it as such, marking the original as failed. Then when the original is removed, move the replacement into its position. This means that 'replacement' and spontaneously become NULL in some situations. Make sure we check for those. It also means that 'rdev' and 'replacement' could appear to be identical - check for that too. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: handle recovery of replacement devices.NeilBrown
If there is a replacement device, then recover to it, reading from any drives - maybe the one being replaced, maybe not. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: Handle replacement devices during resync.NeilBrown
If we need to resync an array which has replacement devices, we always write any block checked to every replacement. If the resync was bitmap-based resync we will then complete the replacement normally. If it was a full resync, we mark the replacements as fully recovered when the resync finishes so no further recovery is needed. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: writes should get directed to replacement as well as original.NeilBrown
When writing, we need to submit two writes, one to the original, and one to the replacements - if there is a replacement. If the write to the replacement results in a write error we just fail the device. We only try to record write errors to the original. This only handles writing new data. Writing for resync/recovery will come later. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: allow removal of failed replacement devices.NeilBrown
Enhance raid10_remove_disk to be able to remove ->replacement as well as ->rdev Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: preferentially read from replacement device if possible.NeilBrown
When reading (for array reads, not for recovery etc) we read from the replacement device if it has recovered far enough. This requires storing the chosen rdev in the 'r10_bio' so we can make sure to drop the ref on the right device when the read finishes. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: change read_balance to return an rdevNeilBrown
It makes more sense to return an rdev than just an index as read_balance() gets a reference to the rdev and so returning the pointer make this more idiomatic. This will be needed in a future patch when we might return a 'replacement' rdev instead of the main rdev. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid10: prepare data structures for handling replacement.NeilBrown
Allow each slot in the RAID10 to have 2 devices, the want_replacement and the replacement. Also an r10bio to have 2 bios, and for resync/recovery allocate the second bio if there are any replacement devices. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: Mark device want_replacement when we see a write error.NeilBrown
Now that WantReplacement drives are replaced cleanly, mark a drive as WantReplacement when we see a write error. It might get failed soon so the WantReplacement flag is irrelevant, but if the write error is recorded in the bad block log, we still want to activate any spare that might be available. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: If there is a spare and a want_replacement device, start replacement.NeilBrown
When attempting to add a spare to a RAID[456] array, also consider adding it as a replacement for a want_replacement device. This requires that common md code attempt hot_add even when the array is not formally degraded. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: recognise replacements when assembling array.NeilBrown
If a Replacement is seen, file it as such. If we see two replacements (or two normal devices) for the one slot, abort. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: handle activation of replacement device when recovery completes.NeilBrown
When recovery completes - as reported by a call to ->spare_active, we clear In_sync on the original and set it on the replacement. Then when the original gets removed we move the replacement from 'replacement' to 'rdev'. This could race with other code that is looking at these pointers, so we use memory barriers and careful ordering to ensure that a reader might see one device twice, but never no devices. Then the readers guard against using both devices, which could only happen when writing. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: detect and handle replacements during recovery.NeilBrown
During recovery we want to write to the replacement but not the original. So we have two new flags - R5_NeedReplace if this stripe has a replacement that needs to be written at some stage - R5_WantReplace if NeedReplace, and the data is available, and a 'sync' has been requested on this stripe. We also distinguish between 'sync and replace' which need to read all other devices, and 'replace' which only needs to read the devices being replaced. Note that during resync we always write to any replacement device. It might not need to be written to, but as we don't read to compare, we have to write to be sure. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: writes should get directed to replacement as well as original.NeilBrown
When writing, we need to submit two writes, one to the original, and one to the replacement - if there is a replacement. If the write to the replacement results in a write error, we just fail the device. We only try to record write errors to the original. When writing for recovery, we shouldn't write to the original. This will be addressed in a subsequent patch that generally addresses recovery. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: allow removal for failed replacement devices.NeilBrown
Enhance raid5_remove_disk to be able to remove ->replacement as well as ->rdev. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: preferentially read from replacement device if possible.NeilBrown
If a replacement device is present and has been recovered far enough, then use it for reading into the stripe cache. If we get an error we don't try to repair it, we just fail the device. A replacement device that gives errors does not sound sensible. This requires removing the setting of R5_ReadError when we get a read error during a read that bypasses the cache. It was probably a bad idea anyway as we don't know that every block in the read caused an error, and it could cause ReadError to be set for the replacement device, which is bad. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: remove redundant bio initialisations.NeilBrown
We current initialise some fields of a bio when preparing a stripe_head, and again just before submitting the request. Remove the duplication by only setting the fields that lower level devices don't touch in raid5_build_block, and only set the changeable fields in ops_run_io. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: raid5.h cleanupNeilBrown
Remove some #defines that are no longer used, and replace some others with an enum. And remove an unused field. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: allow each slot to have an extra replacement deviceNeilBrown
Just enhance data structures to record a second device per slot to be used as a 'replacement' device, replacing the original. We also have a second bio in each slot in each stripe_head. This will only be used when writing to the array - we need to write to both the original and the replacement at the same time, so will need two bios. For now, only try using the replacement drive for aligned-reads. In this case, we prefer the replacement if it has been recovered far enough, otherwise use the original. This includes a small enhancement. Previously we would only do aligned reads if the target device was fully recovered. Now we also do them if it has recovered far enough. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md: create externally visible flags for supporting hot-replace.NeilBrown
hot-replace is a feature being added to md which will allow a device to be replaced without removing it from the array first. With hot-replace a spare can be activated and recovery can start while the original device is still in place, thus allowing a transition from an unreliable device to a reliable device without leaving the array degraded during the transition. It can also be use when the original device is still reliable but it not wanted for some reason. This will eventually be supported in RAID4/5/6 and RAID10. This patch adds a super-block flag to distinguish the replacement device. If an old kernel sees this flag it will reject the device. It also adds two per-device flags which are viewable and settable via sysfs. "want_replacement" can be set to request that a device be replaced. "replacement" is set to show that this device is replacing another device. The "rd%d" links in /sys/block/mdXx/md only apply to the original device, not the replacement. We currently don't make links for the replacement - there doesn't seem to be a need. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md: change hot_remove_disk to take an rdev rather than a number.NeilBrown
Soon an array will be able to have multiple devices with the same raid_disk number (an original and a replacement). So removing a device based on the number won't work. So pass the actual device handle instead. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md: remove test for duplicate device when setting slot number.NeilBrown
When setting the slot number on a device in an active array we currently check that the number is not already in use. We then call into the personality's hot_add_disk function which performs the same test and returns the same error. Thus the common test is not needed. As we will shortly be changing some personalities to allow duplicates in some cases (to support hot-replace), the common test will become inconvenient. So remove the common test. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/bitmap: be more consistent when setting new bits in memory bitmap.NeilBrown
For each active region corresponding to a bit in the bitmap with have a 14bit counter (and some flags). This counts number of active writes + bit in the on-disk bitmap + delay-needed. The "delay-needed" is because we always want a delay before clearing a bit. So the number here is normally number of active writes plus 2. If there have been no writes for a while, we drop to 1. If still no writes we clear the bit and drop to 0. So for consistency, when setting bit from the on-disk bitmap or by request from user-space it is best to set the counter to '2' to start with. In particular we might also set the NEEDED_MASK flag at this time, and in all other cases NEEDED_MASK is only set when the counter is 2 or more. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: be more thorough in calculating 'degraded' value.NeilBrown
When an array is being reshaped to change the number of devices, the two halves can be differently degraded. e.g. one could be missing a device and the other not. So we need to be more careful about calculating the 'degraded' attribute. Instead of just inc/dec at appropriate times, perform a full re-calculation examining both possible cases. This doesn't happen often so it not a big cost, and we already have most of the code to do it. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/bitmap: daemon_work cleanup.NeilBrown
We have a variable 'mddev' in this function, but repeatedly get the same value by dereferencing bitmap->mddev. There is room for simplification here... Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md: allow non-privileged uses to GET_*_INFO about raid arrays.NeilBrown
The info is already available in /proc/mdstat and /sys/block in an accessible form so there is no point in putting a road-block in the ioctl for information gathering. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/bitmap: It is OK to clear bits during recovery.NeilBrown
commit d0a4bb492772ce5c4bdfba3744a99ed6f6fb238f introduced a regression which is annoying but fairly harmless. When writing to an array that is undergoing recovery (a spare in being integrated into the array), writing to the array will set bits in the bitmap, but they will not be cleared when the write completes. For bits covering areas that have not been recovered yet this is not a problem as the recovery will clear the bits. However bits set in already-recovered region will stay set and never be cleared. This doesn't risk data integrity. The only negatives are: - next time there is a crash, more resyncing than necessary will be done. - the bitmap doesn't look clean, which is confusing. While an array is recovering we don't want to update the 'events_cleared' setting in the bitmap but we do still want to clear bits that have very recently been set - providing they were written to the recovering device. So split those two needs - which previously both depended on 'success' and always clear the bit of the write went to all devices. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md: don't give up looking for spares on first failure-to-addNeilBrown
Before performing a recovery we try to remove any spares that might not be working, then add any that might have become relevant. Currently we abort on the first spare that cannot be added. This is a false optimisation. It is conceivable that - depending on rules in the personality - a subsequent spare might be accepted. Also the loop does other things like count the available spares and reset the 'recovery_offset' value. If we abort early these might not happen properly. So remove the early abort. In particular if you have an array what is undergoing recovery and which has extra spares, then the recovery may not restart after as reboot as the could of 'spares' might end up as zero. Reported-by: Anssi Hannula <anssi.hannula@iki.fi> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/raid5: ensure correct assessment of drives during degraded reshape.NeilBrown
While reshaping a degraded array (as when reshaping a RAID0 by first converting it to a degraded RAID4) we currently get confused about which devices are in_sync. In most cases we get it right, but in the region that is being reshaped we need to treat non-failed devices as in-sync when we have the data but haven't actually written it out yet. Reported-by: Adam Kwolek <adam.kwolek@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-22md/linear: fix hot-add of devices to linear arrays.NeilBrown
commit d70ed2e4fafdbef0800e73942482bb075c21578b broke hot-add to a linear array. After that commit, metadata if not written to devices until they have been fully integrated into the array as determined by saved_raid_disk. That patch arranged to clear that field after a recovery completed. However for linear arrays, there is no recovery - the integration is instantaneous. So we need to explicitly clear the saved_raid_disk field. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-09md: raid5 crash during degradationAdam Kwolek
NULL pointer access causes crash in raid5 module. Signed-off-by: Adam Kwolek <adam.kwolek@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08md/raid5: never wait for bad-block acks on failed device.NeilBrown
Once a device is failed we really want to completely ignore it. It should go away soon anyway. In particular the presence of bad blocks on it should not cause us to block as we won't be trying to write there anyway. So as soon as we can check if a device is Faulty, do so and pretend that it is already gone if it is Faulty. Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08md: ensure new badblocks are handled promptly.NeilBrown
When we mark blocks as bad we need them to be acknowledged by the metadata handler promptly. For an in-kernel metadata handler that was already being done. But for an external metadata handler we need to alert it of the change by sending a notification through the sysfs file. This adds that notification. Signed-off-by: NeilBrown <neilb@suse.de>