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2012-07-13Merge tag 'md-3.5-fixes' of git://neil.brown.name/mdLinus Torvalds
Pull use-after-free RAID1 bugfix from NeilBrown. * tag 'md-3.5-fixes' of git://neil.brown.name/md: md/raid1: fix use-after-free bug in RAID1 data-check code.
2012-07-09md/raid1: fix use-after-free bug in RAID1 data-check code.NeilBrown
This bug has been present ever since data-check was introduce in 2.6.16. However it would only fire if a data-check were done on a degraded array, which was only possible if the array has 3 or more devices. This is certainly possible, but is quite uncommon. Since hot-replace was added in 3.3 it can happen more often as the same condition can arise if not all possible replacements are present. The problem is that as soon as we submit the last read request, the 'r1_bio' structure could be freed at any time, so we really should stop looking at it. If the last device is being read from we will stop looking at it. However if the last device is not due to be read from, we will still check the bio pointer in the r1_bio, but the r1_bio might already be free. So use the read_targets counter to make sure we stop looking for bios to submit as soon as we have submitted them all. This fix is suitable for any -stable kernel since 2.6.16. Cc: stable@vger.kernel.org Reported-by: Arnold Schulz <arnysch@gmx.net> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03Merge tag 'md-3.5-fixes' of git://neil.brown.name/mdLinus Torvalds
Pull raid10 build failure fix from NeilBrown: "I really shouldn't do important things late in the day. It seems that I get careless." * tag 'md-3.5-fixes' of git://neil.brown.name/md: md/raid10: fix careless build error
2012-07-04md/raid10: fix careless build errorNeilBrown
build error introduced by commit b357f04a67c2aeee8 That function doesn't get extra args until a later patch. Bother. Reported-by: Fengguang Wu <wfg@linux.intel.com> Reported-by: Simon Kirby <sim@hostway.ca> Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03Merge tag 'dm-3.5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm Pull device-mapper fixes from Alasdair G Kergon: "Four minor thin provisioning fixes and correct and update dm-verity documentation." * tag 'dm-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: dm: verity fix documentation dm persistent data: fix allocation failure in space map checker init dm persistent data: handle space map checker creation failure dm persistent data: fix shadow_info_leak on dm_tm_destroy dm thin: commit metadata before creating metadata snapshot
2012-07-03dm persistent data: fix allocation failure in space map checker initMike Snitzer
If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and memory is fragmented and a sufficiently-large metadata device is used in a thin pool then the space map checker will fail to allocate the memory it requires. Switch from kmalloc to vmalloc to allow larger virtually contiguous allocations for the space map checker's internal count arrays. Reported-by: Vivek Goyal <vgoyal@redhat.com> Cc: stable@kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03dm persistent data: handle space map checker creation failureMike Snitzer
If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create() fails, dm_tm_create_internal() would still return success even though it cleaned up all resources it was supposed to have created. This will lead to a kernel crash: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC ... RIP: 0010:[<ffffffff81593659>] [<ffffffff81593659>] dm_bufio_get_block_size+0x9/0x20 Call Trace: [<ffffffff81599bae>] dm_bm_block_size+0xe/0x10 [<ffffffff8159b8b8>] sm_ll_init+0x78/0xd0 [<ffffffff8159c1a6>] sm_ll_new_disk+0x16/0xa0 [<ffffffff8159c98e>] dm_sm_disk_create+0xfe/0x160 [<ffffffff815abf6e>] dm_pool_metadata_open+0x16e/0x6a0 [<ffffffff815aa010>] pool_ctr+0x3f0/0x900 [<ffffffff8158d565>] dm_table_add_target+0x195/0x450 [<ffffffff815904c4>] table_load+0xe4/0x330 [<ffffffff815917ea>] ctl_ioctl+0x15a/0x2c0 [<ffffffff81591963>] dm_ctl_ioctl+0x13/0x20 [<ffffffff8116a4f8>] do_vfs_ioctl+0x98/0x560 [<ffffffff8116aa51>] sys_ioctl+0x91/0xa0 [<ffffffff81869f52>] system_call_fastpath+0x16/0x1b Fix the space map checker code to return an appropriate ERR_PTR and have dm_sm_disk_create() and dm_tm_create_internal() check for it with IS_ERR. Reported-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03dm persistent data: fix shadow_info_leak on dm_tm_destroyMike Snitzer
Cleanup the shadow table before destroying the transaction manager. Reference: leak was identified with kmemleak when running test_discard_random_sectors in the thinp-test-suite. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03dm thin: commit metadata before creating metadata snapshotJoe Thornber
Userland sometimes sees a corrupt metadata block if metadata is changing rapidly when a metadata snapshot is reserved for userland, To make the problem go away, commit before we take the metadata snapshot (which is a sensible thing to do anyway). The checksums mean userland spots this corruption immediately so there's no risk of acting on incorrect data. No corruption exists from the kernel's point of view, and thin_check passes after pool shutdown. I believe this is to do with shared blocks at the first level of the {device, mapping} btree. Prior to the metadata-snap support no sharing at this level was possible, so this patch is only required after commit cc8394d86f045b86ff303d3c9e4ce47d97148951 ("dm thin: provide userspace access to pool metadata"). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03md: fix up plugging (again).NeilBrown
The value returned by "mddev_check_plug" is only valid until the next 'schedule' as that will unplug things. This could happen at any call to mempool_alloc. So just calling mddev_check_plug at the start doesn't really make sense. So call it just before, or just after, queuing things for the thread. As the action that happens at unplug is to wake the thread, this makes lots of sense. If we cannot add a plug (which requires a small GFP_ATOMIC alloc) we wake thread immediately. RAID5 is a bit different. Requests are queued for the thread and the thread is woken by release_stripe. So we don't need to wake the thread on failure. However the thread doesn't perform certain actions when there is any active plug, so it is important to install a plug before waking the thread. So for RAID5 we install the plug *before* queuing the request and waking the thread. Without this patch it is possible for raid1 or raid10 to queue a request without then waking the thread, resulting in the array locking up. Also change raid10 to only flush_pending_write when there are not active plugs, just like raid1. This patch is suitable for 3.0 or later. I plan to submit it to -stable, but I'll like to let it spend a few weeks in mainline first to be sure it is completely safe. Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md: support re-add of recovering devices.NeilBrown
We currently only allow a device to be re-added if it appear to be in-sync. This is overly restrictive as it may be desirable to re-add a device that is in the middle of recovery. So remove the test for "InSync" - the test on rdev->raid_disk is sufficient to ensure that the re-add will succeed. Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com> Tested-by: Alexander Lyakas <alex.bolshoy@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid1: fix bug in read_balance introduced by hot-replaceNeilBrown
When we added hot_replace we doubled the number of devices that could be in a RAID1 array. So we doubled how far read_balance would search. Unfortunately we didn't double the point at which it looped back to the beginning - so it effectively loops over all non-replacement disks twice. This doesn't cause bad behaviour, but it pointless and means we never read from replacement devices. Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03raid5: delayed stripe fixShaohua Li
There isn't locking setting STRIPE_DELAYED and STRIPE_PREREAD_ACTIVE bits, but the two bits have relationship. A delayed stripe can be moved to hold list only when preread active stripe count is below IO_THRESHOLD. If a stripe has both the bits set, such stripe will be in delayed list and preread count not 0, which will make such stripe never leave delayed list. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid456: When read error cannot be recovered, record bad blockmajianpeng
We may not be able to fix a bad block if: - the array is degraded - the over-write fails. In these cases we currently eject the device, but we should record a bad block if possible. Signed-off-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md: make 'name' arg to md_register_thread non-optional.NeilBrown
Having the 'name' arg optional and defaulting to the current personality name is no necessary and leads to errors, as when changing the level of an array we can end up using the name of the old level instead of the new one. So make it non-optional and always explicitly pass the name of the level that the array will be. Reported-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid10: fix failure when trying to repair a read error.NeilBrown
commit 58c54fcca3bac5bf9290cfed31c76e4c4bfbabaf md/raid10: handle further errors during fix_read_error better. in 3.1 added "r10_sync_page_io" which takes an IO size in sectors. But we were passing the IO size in bytes!!! This resulting in bio_add_page failing, and empty request being sent down, and a consequent BUG_ON in scsi_lib. [fix missing space in error message at same time] This fix is suitable for 3.1.y and later. Cc: stable@vger.kernel.org Reported-by: Christian Balzer <chibi@gol.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid5: fix refcount problem when blocked_rdev is set.NeilBrown
commit 43220aa0f22cd3ce5b30246d50ccd696d119edea md/raid5: fix a hang on device failure. fixed a hang, but introduced a refcounting in-balance so that if the presence of bad-blocks ever caused an rdev to be 'blocked' we would increment the refcount on the rdev and never decrement it. So added the needed rdev_dec_pending when md_wait_for_blocked_rdev is not called. Reported-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md:Add blk_plug in sync_thread.majianpeng
Add blk_plug in sync_thread will increase the performance of sync. Because sync_thread did not blk_plug,so when raid sync, the bio merge not well. Testing environment: SATA controller: Intel Corporation 82801JI (ICH10 Family) SATA AHCI Controller. OS:Linux xxx 3.5.0-rc2+ #340 SMP Tue Jun 12 09:00:25 CST 2012 x86_64 x86_64 x86_64 GNU/Linux. RAID5: four ST31000524NS disk. Without blk_plug:recovery speed about 63M/Sec; Add blk_plug:recovery speed about 120M/Sec. Using blktrace: blktrace -d /dev/sdb -w 60 -o -|blkparse -i - without blk_plug: Total (8,16): Reads Queued: 309811, 1239MiB Writes Queued: 0, 0KiB Read Dispatches: 283583, 1189MiB Write Dispatches: 0, 0KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 273351, 1149MiB Writes Completed: 0, 0KiB Read Merges: 23533, 94132KiB Write Merges: 0, 0KiB IO unplugs: 0 Timer unplugs: 0 add blk_plug: Total (8,16): Reads Queued: 428697, 1714MiB Writes Queued: 0, 0KiB Read Dispatches: 3954, 1714MiB Write Dispatches: 0, 0KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 3956, 1715MiB Writes Completed: 0, 0KiB Read Merges: 424743, 1698MiB Write Merges: 0, 0KiB IO unplugs: 0 Timer unplugs: 3384 The ratio of merge will be markedly increased. Signed-off-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid5: In ops_run_io, inc nr_pending before calling md_wait_for_blocked_rdevmajianpeng
In ops_run_io(), the call to md_wait_for_blocked_rdev will decrement nr_pending so we lose the reference we hold on the rdev. So atomic_inc it first to maintain the reference. This bug was introduced by commit 73e92e51b7969ef5477d md/raid5. Don't write to known bad block on doubtful devices. which appeared in 3.0, so patch is suitable for stable kernels since then. Cc: stable@vger.kernel.org Signed-off-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid5: Do not add data_offset before call to is_badblockmajianpeng
In chunk_aligned_read() we are adding data_offset before calling is_badblock. But is_badblock also adds data_offset, so that is bad. So move the addition of data_offset to after the call to is_badblock. This bug was introduced by commit 31c176ecdf3563140e639 md/raid5: avoid reading from known bad blocks. which first appeared in 3.0. So that patch is suitable for any -stable kernel from 3.0.y onwards. However it will need minor revision for most of those (as the comment didn't appear until recently). Cc: stable@vger.kernel.org Signed-off-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid5: prefer replacing failed devices over want-replacement devices.NeilBrown
If a RAID5 has both a failed device and a device marked as 'WantReplacement', then we should preferentially replace the failed device. However the current code replaces whichever is found first. So split into 2 loops, check fail failed/missing first, and only check for WantReplacement if nothing is failed or missing. Reported-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03md/raid10: Don't try to recovery unmatched (and unused) chunks.NeilBrown
If a RAID10 has an odd number of chunks - as might happen when there are an odd number of devices - the last chunk has no pair and so is not mirrored. We don't store data there, but when recovering the last device in an array we retry to recover that last chunk from a non-existent location. This results in an error, and the recovery aborts. When we get to that last chunk we should just stop - there is nothing more to do anyway. This bug has been present since the introduction of RAID10, so the patch is appropriate for any -stable kernel. Cc: stable@vger.kernel.org Reported-by: Christian Balzer <chibi@gol.com> Tested-by: Christian Balzer <chibi@gol.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-06-06Merge tag 'md-3.5-fixes' of git://neil.brown.name/mdLinus Torvalds
Pull two md fixes from NeilBrown: "One sparse-warning fix, one bugfix for 3.4-stable" * tag 'md-3.5-fixes' of git://neil.brown.name/md: md: raid1/raid10: fix problem with merge_bvec_fn lib/raid6: fix sparse warnings in recovery functions
2012-06-02Merge tag 'dm-3.5-changes-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm Pull device-mapper updates from Alasdair G Kergon: "Improve multipath's retrying mechanism in some defined circumstances and provide a simple reserve/release mechanism for userspace tools to access thin provisioning metadata while the pool is in use." * tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: dm thin: provide userspace access to pool metadata dm thin: use slab mempools dm mpath: allow ioctls to trigger pg init dm mpath: delay retry of bypassed pg dm mpath: reduce size of struct multipath
2012-06-03dm thin: provide userspace access to pool metadataJoe Thornber
This patch implements two new messages that can be sent to the thin pool target allowing it to take a snapshot of the _metadata_. This, read-only snapshot can be accessed by userland, concurrently with the live target. Only one metadata snapshot can be held at a time. The pool's status line will give the block location for the current msnap. Since version 0.1.5 of the userland thin provisioning tools, the thin_dump program displays the msnap as follows: thin_dump -m <msnap root> <metadata dev> Available here: https://github.com/jthornber/thin-provisioning-tools Now that userland can access the metadata we can do various things that have traditionally been kernel side tasks: i) Incremental backups. By using metadata snapshots we can work out what blocks have changed over time. Combined with data snapshots we can ensure the data doesn't change while we back it up. A short proof of concept script can be found here: https://github.com/jthornber/thinp-test-suite/blob/master/incremental_backup_example.rb ii) Migration of thin devices from one pool to another. iii) Merging snapshots back into an external origin. iv) Asyncronous replication. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03dm thin: use slab mempoolsMike Snitzer
Use dedicated caches prefixed with a "dm_" name rather than relying on kmalloc mempools backed by generic slab caches so the memory usage of thin provisioning (and any leaks) can be accounted for independently. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03dm mpath: allow ioctls to trigger pg initMikulas Patocka
After the failure of a group of paths, any alternative paths that need initialising do not become available until further I/O is sent to the device. Until this has happened, ioctls return -EAGAIN. With this patch, new paths are made available in response to an ioctl too. The processing of the ioctl gets delayed until this has happened. Instead of returning an error, we submit a work item to kmultipathd (that will potentially activate the new path) and retry in ten milliseconds. Note that the patch doesn't retry an ioctl if the ioctl itself fails due to a path failure. Such retries should be handled intelligently by the code that generated the ioctl in the first place, noting that some SCSI commands should not be retried because they are not idempotent (XOR write commands). For commands that could be retried, there is a danger that if the device rejected the SCSI command, the path could be errorneously marked as failed, and the request would be retried on another path which might fail too. It can be determined if the failure happens on the device or on the SCSI controller, but there is no guarantee that all SCSI drivers set these flags correctly. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03dm mpath: delay retry of bypassed pgMike Christie
If I/O needs retrying and only bypassed priority groups are available, set the pg_init_delay_retry flag to wait before retrying. If, for example, the reason for the bypass is that the controller is getting reset or there is a firmware upgrade happening, retrying right away would cause a flood of log messages and retries for what could be a few seconds or even several minutes. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03dm mpath: reduce size of struct multipathMike Snitzer
Move multipath structure's 'lock' and 'queue_size' members to eliminate two 4-byte holes. Also use a bit within a single unsigned int for each existing flag (saves 8-bytes). This allows future flags to be added without each consuming an unsigned int. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-05-31md: raid1/raid10: fix problem with merge_bvec_fnNeilBrown
The new merge_bvec_fn which calls the corresponding function in subsidiary devices requires that mddev->merge_check_needed be set if any child has a merge_bvec_fn. However were were only setting that when a device was hot-added, not when a device was present from the start. This bug was introduced in 3.4 so patch is suitable for 3.4.y kernels. However that are conflicts in raid10.c so a separate patch will be needed for 3.4.y. Cc: stable@vger.kernel.org Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-23Merge tag 'md-3.5' of git://neil.brown.name/mdLinus Torvalds
Pull md updates from NeilBrown: "It's been a busy cycle for md - lots of fun stuff here.. if you like this kind of thing :-) Main features: - RAID10 arrays can be reshaped - adding and removing devices and changing chunks (not 'far' array though) - allow RAID5 arrays to be reshaped with a backup file (not tested yet, but the priciple works fine for RAID10). - arrays can be reshaped while a bitmap is present - you no longer need to remove it first - SSSE3 support for RAID6 syndrome calculations and of course a number of minor fixes etc." * tag 'md-3.5' of git://neil.brown.name/md: (56 commits) md/bitmap: record the space available for the bitmap in the superblock. md/raid10: Remove extras after reshape to smaller number of devices. md/raid5: improve removal of extra devices after reshape. md: check the return of mddev_find() MD RAID1: Further conditionalize 'fullsync' DM RAID: Use md_error() in place of simply setting Faulty bit DM RAID: Record and handle missing devices DM RAID: Set recovery flags on resume md/raid5: Allow reshape while a bitmap is present. md/raid10: resize bitmap when required during reshape. md: allow array to be resized while bitmap is present. md/bitmap: make sure reshape request are reflected in superblock. md/bitmap: add bitmap_resize function to allow bitmap resizing. md/bitmap: use DIV_ROUND_UP instead of open-code md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap' md/bitmap: make bitmap bitops atomic. md/bitmap: make _page_attr bitops atomic. md/bitmap: merge bitmap_file_unmap and bitmap_file_put. md/bitmap: remove async freeing of bitmap file. md/bitmap: convert some spin_lock_irqsave to spin_lock_irq ...
2012-05-22md/bitmap: record the space available for the bitmap in the superblock.NeilBrown
Now that bitmaps can grow and shrink it is best if we record how much space is available. This means that when we reduce the size of the bitmap we won't "lose" the space for late when we might want to increase the size of the bitmap again. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/raid10: Remove extras after reshape to smaller number of devices.NeilBrown
When a reshape which reduced the number of devices finishes we must remove the extra devices. So ensure that raid10_remove_disk won't try to keep them, and have raid10_finish_reshape clear the 'in_sync' flag. Then remove_and_add_spares will be able to remove them. Reported-by: Hannes Reinecke <hare@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/raid5: improve removal of extra devices after reshape.NeilBrown
After a reshape which reduced the number of devices we need to disconnect the extra devices. The code for this doesn't currently handle 'replacement' devices. It is very unlikely that such devices will be present, but it is safest to handle them anyway. So simplify the handling. Just clear In_sync and leave it to remove_and_add_spaces (which will be called soon) to do the real works. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md: check the return of mddev_find()Yuanhan Liu
Check the return of mddev_find(), since it may fail due to out of memeory or out of usable minor number. The reason I chose -ENODEV instead of -ENOMEM or something else is md_alloc() function chose that ;) Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22MD RAID1: Further conditionalize 'fullsync'Jonathan Brassow
A RAID1 device does not necessarily need a fullsync if the bitmap can be used instead. Similar to commit d6b212f4b19da5301e6b6eca562e5c7a2a6e8c8d in raid5.c, if a raid1 device can be brought back (i.e. from a transient failure) it shouldn't need a complete resync. Provided the bitmap is not to old, it will have recorded the areas of the disk that need recovery. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22DM RAID: Use md_error() in place of simply setting Faulty bitJonathan Brassow
When encountering an error while reading the superblock, call md_error. We are currently setting the 'Faulty' bit on one of the array devices when an error is encountered while reading the superblock of a dm-raid array. We should be calling md_error(), as it handles the error more completely. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22DM RAID: Record and handle missing devicesJonathan Brassow
Missing dm-raid devices should be recorded in the superblock When specifying the devices that compose a DM RAID array, it is possible to denote failed or missing devices with '-'s. When this occurs, we must record this in the superblock. We do this by checking if the array position's data device is missing and then forcing MD to record the superblock by setting 'MD_CHANGE_DEVS' in 'raid_resume'. If we do not cause the superblock to be rewritten by the resume function, it is possible for a stale superblock to be written by an out-going in-active table (during 'raid_dtr'). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22DM RAID: Set recovery flags on resumeJonathan Brassow
Properly initialize MD recovery flags when resuming device-mapper devices. When a device-mapper device is suspended, all I/O must stop. This is done by calling 'md_stop_writes' and 'mddev_suspend'. These calls in-turn manipulate the recovery flags - including setting 'MD_RECOVERY_FROZEN'. The DM device may have been suspended while recovery was not yet complete, so the process needs to pick-up where it left off. Since 'mddev_resume' does not unset 'MD_RECOVERY_FROZEN' and set 'MD_RECOVERY_NEEDED', we must do it ourselves. 'MD_RECOVERY_NEEDED' can safely be set in 'mddev_resume', but 'MD_RECOVERY_FROZEN' must be set outside of 'mddev_resume' due to how MD handles RAID reshaping. (e.g. It is possible for a user to delay reshaping a RAID5->RAID6 by purposefully setting 'MD_RECOVERY_FROZEN'. Clearing it in 'mddev_resume' would override the desired behavior.) Because 'mddev_resume' already unconditionally calls 'md_wakeup_thread(mddev->thread)' there is no need to make this call from 'raid_resume' since it calls 'mddev_resume'. Also clean up where level_store calls mddev_resume() - it current duplicates some of the funcitons of that call. - NB Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/raid5: Allow reshape while a bitmap is present.NeilBrown
We always should have allowed this. A raid5 reshape doesn't change the size of the bitmap, so not need to restrict it. Also add a test to make sure we don't try to start a reshape on a failed array. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/raid10: resize bitmap when required during reshape.NeilBrown
If a reshape changes the size of the array, then we can now update the bitmap to suit - so do so. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md: allow array to be resized while bitmap is present.NeilBrown
Now that bitmaps can be resized, we can allow an array to be resized while the bitmap is present. This only covers resizing that involves changing the effective size of member devices, not resizing that changes the number of devices. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: make sure reshape request are reflected in superblock.NeilBrown
As a reshape may change the sync_size and/or chunk_size, we need to update these whenever we write out the bitmap superblock. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: add bitmap_resize function to allow bitmap resizing.NeilBrown
This function will allocate the new data structures and copy bits across from old to new, allowing for the possibility that the chunksize has changed. Use the same function for performing the initial allocation of the structures. This improves test coverage. When bitmap_resize is used to resize an existing bitmap, it only copies '1' bits in, not '0' bits. So when allocating the bitmap, ensure everything is initialised to ZERO. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: use DIV_ROUND_UP instead of open-codeNeilBrown
Also take the opportunity to simplify CHUNK_BLOCK_RATIO. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'NeilBrown
The new "struct bitmap_counts" contains all the fields that are related to counting the number of active writes in each bitmap chunk. Having this separate will make it easier to change the chunksize or overall size of a bitmap atomically. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: make bitmap bitops atomic.NeilBrown
This allows us to remove spinlock protection which is more heavy-weight than simple atomics. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: make _page_attr bitops atomic.NeilBrown
Using e.g. set_bit instead of __set_bit and using test_and_clear_bit allow us to remove some locking and contract other locked ranges. It is rare that we set or clear a lot of these bits, so gain should outweigh any cost. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: merge bitmap_file_unmap and bitmap_file_put.NeilBrown
There functions really do one thing together: release the 'bitmap_storage'. So make them just one function. Since we removed the locking (previous patch), we don't need to zero any fields before freeing them, so it all becomes a bit simpler. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: remove async freeing of bitmap file.NeilBrown
There is no real value in freeing things the moment there is an error. It is just as good to free the bitmap file and pages when the bitmap is explicitly removed (and replaced?) or at shutdown. With this gone, the bitmap will only disappear when the array is quiescent, so we can remove some locking. As the 'filemap' doesn't disappear now, include extra checks before trying to write any of it out. Also remove the check for "has it disappeared" in bitmap_daemon_write(). Signed-off-by: NeilBrown <neilb@suse.de>