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path: root/drivers/md/raid1.c
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2011-06-08MD: raid1 changes to allow use by device mapperJonathan Brassow
MD RAID1: Changes to allow RAID1 to be used by device-mapper (dm-raid.c) Added the necessary congestion function and conditionalize calls requiring an array 'queue' or 'gendisk'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md: allow resync_start to be set while an array is active.NeilBrown
The sysfs attribute 'resync_start' (known internally as recovery_cp), records where a resync is up to. A value of 0 means the array is not known to be in-sync at all. A value of MaxSector means the array is believed to be fully in-sync. When the size of member devices of an array (RAID1,RAID4/5/6) is increased, the array can be increased to match. This process sets resync_start to the old end-of-device offset so that the new part of the array gets resynced. However with RAID1 (and RAID6) a resync is not technically necessary and may be undesirable. So it would be good if the implied resync after the array is resized could be avoided. So: change 'resync_start' so the value can be changed while the array is active, and as a precaution only allow it to be changed while resync/recovery is 'frozen'. Changing it once resync has started is not going to be useful anyway. This allows the array to be resized without a resync by: write 'frozen' to 'sync_action' write new size to 'component_size' (this will set resync_start) write 'none' to 'resync_start' write 'idle' to 'sync_action'. Also slightly improve some tests on recovery_cp when resizing raid1/raid5. Now that an arbitrary value could be set we should be more careful in our tests. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid1: improve handling of pages allocated for write-behind.NeilBrown
The current handling and freeing of these pages is a bit fragile. We only keep the list of allocated pages in each bio, so we need to still have a valid bio when freeing the pages, which is a bit clumsy. So simply store the allocated page list in the r1_bio so it can easily be found and freed when we are finished with the r1_bio. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid1: try fix_sync_read_error before process_checks.NeilBrown
If we get a read error during resync/recovery we current repeat with single-page reads to find out just where the error is, and possibly read each page from a different device. With check/repair we don't currently do that, we just fail. However it is possible that while all devices fail on the large 64K read, we might be able to satisfy each 4K from one device or another. So call fix_sync_read_error before process_checks to maximise the chance of finding good data and writing it out to the devices with read errors. For this to work, we need to set the 'uptodate' flags properly after fix_sync_read_error has succeeded. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid1: tidy up new functions: process_checks and fix_sync_read_error.NeilBrown
These changes are mostly cosmetic: 1/ change mddev->raid_disks to conf->raid_disks because the later is technically safer, though in current practice it doesn't matter in this particular context. 2/ Rearrange two for / if loops to have an early 'continue' so the body of the 'if' doesn't need to be indented so much. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid1: split out two sub-functions from sync_request_writeNeilBrown
sync_request_write is too big and too deep. So split out two self-contains bits of functionality into separate function. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid1: clean up read_balance.NeilBrown
read_balance has two loops which both look for a 'best' device based on slightly different criteria. This is clumsy and makes is hard to add extra criteria. So replace it all with a single loop that combines everything. Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18md: fix up raid1/raid10 unplugging.NeilBrown
We just need to make sure that an unplug event wakes up the md thread, which is exactly what mddev_check_plugged does. Also remove some plug-related code that is no longer needed. Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18md: use new plugging interface for RAID IO.NeilBrown
md/raid submits a lot of IO from the various raid threads. So adding start/finish plug calls to those so that some plugging happens. Signed-off-by: NeilBrown <neilb@suse.de>
2011-03-17block: Require subsystems to explicitly allocate bio_set integrity mempoolMartin K. Petersen
MD and DM create a new bio_set for every metadevice. Each bio_set has an integrity mempool attached regardless of whether the metadevice is capable of passing integrity metadata. This is a waste of memory. Instead we defer the allocation decision to MD and DM since we know at metadevice creation time whether integrity passthrough is needed or not. Automatic integrity mempool allocation can then be removed from bioset_create() and we make an explicit integrity allocation for the fs_bio_set. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Acked-by: Mike Snitzer <snizer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/coreJens Axboe
Conflicts: block/blk-core.c block/blk-flush.c drivers/md/raid1.c drivers/md/raid10.c drivers/md/raid5.c fs/nilfs2/btnode.c fs/nilfs2/mdt.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-02-21md: avoid spinlock problem in blk_throtl_exitNeilBrown
blk_throtl_exit assumes that ->queue_lock still exists, so make sure that it does. To do this, we stop redirecting ->queue_lock to conf->device_lock and leave it pointing where it is initialised - __queue_lock. As the blk_plug functions check the ->queue_lock is held, we now take that spin_lock explicitly around the plug functions. We don't need the locking, just the warning removal. This is needed for any kernel with the blk_throtl code, which is which is 2.6.37 and later. Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14md-new-param-to_sync_page_ioJonathan Brassow
Add new parameter to 'sync_page_io'. The new parameter allows us to distinguish between metadata and data operations. This becomes important later when we add the ability to use separate devices for data and metadata. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14md: Fix single printks with multiple KERN_<level>sJoe Perches
Noticed-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24md/raid1: really fix recovery looping when single good device fails.NeilBrown
Commit 4044ba58dd15cb01797c4fd034f39ef4a75f7cc3 supposedly fixed a problem where if a raid1 with just one good device gets a read-error during recovery, the recovery would abort and immediately restart in an infinite loop. However it depended on raid1_remove_disk removing the spare device from the array. But that does not happen in this case. So add a test so that in the 'recovery_disabled' case, the device will be removed. This suitable for any kernel since 2.6.29 which is when recovery_disabled was introduced. Cc: stable@kernel.org Reported-by: Sebastian Färber <faerber@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29md: tidy up device searches in read_balance.NeilBrown
The code for searching through the device list to read-balance in raid1 is rather clumsy and hard to follow. Try to simplify it a bit. No important functionality change here. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29md/raid1: fix some typos in comments.NeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29md/raid1: discard unused variable.NeilBrown
This structure field (flushing_bio_list) is never used, so remove it. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use separate bio pool for each md device.NeilBrown
bio_clone and bio_alloc allocate from a common bio pool. If an md device is stacked with other devices that use this pool, or under something like swap which uses the pool, then the multiple calls on the pool can cause deadlocks. So allocate a local bio pool for each md array and use that rather than the common pool. This pool is used both for regular IO and metadata updates. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: change type of first arg to sync_page_io.NeilBrown
Currently sync_page_io takes a 'bdev'. Every caller passes 'rdev->bdev'. We will soon want another field out of the rdev in sync_page_io, So just pass the rdev instead of the bdev out of it. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md/raid1: perform mem allocation before disabling writes during resync.NeilBrown
Though this mem alloc is GFP_NOIO an so will not deadlock, it seems better to do the allocation before 'raise_barrier' which stops any IO requests while the resync proceeds. raid10 always uses this order, so it is at least consistent to do the same in raid1. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use bio_kmalloc rather than bio_alloc when failure is acceptable.NeilBrown
bio_alloc can never fail (as it uses a mempool) but an block indefinitely, especially if the caller is holding a reference to a previously allocated bio. So these to places which both handle failure and hold multiple bios should not use bio_alloc, they should use bio_kmalloc. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: Fix possible deadlock with multiple mempool allocations.NeilBrown
It is not safe to allocate from a mempool while holding an item previously allocated from that mempool as that can deadlock when the mempool is close to exhaustion. So don't use a bio list to collect the bios to write to multiple devices in raid1 and raid10. Instead queue each bio as it becomes available so an unplug will activate all previously allocated bios and so a new bio has a chance of being allocated. This means we must set the 'remaining' count to '1' before submitting any requests, then when all are submitted, decrement 'remaining' and possible handle the write completion at that point. Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Tested-by: Torsten Kaiser <just.for.lkml@googlemail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use sector_t in bitmap_get_counterNeilBrown
bitmap_get_counter returns the number of sectors covered by the counter in a pass-by-reference variable. In some cases this can be very large, so make it a sector_t for safety. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-19Merge branch 'v2.6.36-rc8' into for-2.6.37/barrierJens Axboe
Conflicts: block/blk-core.c drivers/block/loop.c mm/swapfile.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-07md/raid1: minor bio initialisation improvements.NeilBrown
When performing a resync we pre-allocate some bios and repeatedly use them. This requires us to re-initialise them each time. One field (bi_comp_cpu) and some flags weren't being initiaised reliably. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-07md/raid1: avoid overflow in raid1 resync when bitmap is in use.NeilBrown
bitmap_start_sync returns - via a pass-by-reference variable - the number of sectors before we need to check with the bitmap again. Since commit ef4256733506f245 this number can be substantially larger, 2^27 is a common value. Unfortunately it is an 'int' and so when raid1.c:sync_request shifts it 9 places to the left it becomes 0. This results in a zero-length read which the scsi layer justifiably complains about. This patch just removes the shift so the common case becomes safe with a trivially-correct patch. In the next merge window we will convert this 'int' to a 'sector_t' Reported-by: "George Spelvin" <linux@horizon.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-10md: implment REQ_FLUSH/FUA supportTejun Heo
This patch converts md to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. In the core part (md.c), the following changes are notable. * Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with processing of other requests and thus there is no reason to mark the queue congested while FLUSH/FUA is in progress. * REQ_FLUSH/FUA failures are final and its users don't need retry logic. Retry logic is removed. * Preflush needs to be issued to all member devices but FUA writes can be handled the same way as other writes - their processing can be deferred to request_queue of member devices. md_barrier_request() is renamed to md_flush_request() and simplified accordingly. For linear, raid0 and multipath, the core changes are enough. raid1, 5 and 10 need the following conversions. * raid1: Handling of FLUSH/FUA bio's can simply be deferred to request_queues of member devices. Barrier related logic removed. * raid5: Queue draining logic dropped. FUA bit is propagated through biodrain and stripe resconstruction such that all the updated parts of the stripe are written out with FUA writes if any of the dirtying writes was FUA. preread_active_stripes handling in make_request() is updated as suggested by Neil Brown. * raid10: FUA bit needs to be propagated to write clones. linear, raid0, 1, 5 and 10 tested. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-18md raid-1/10 Fix bio_rw bit manipulations againNeilBrown
commit 7b6d91daee5cac6402186ff224c3af39d79f4a0e changed the behaviour of a few variables in raid1 and raid10 from flags to bit-sets, but left them as type 'bool' so they did not work. Change them (back) to unsigned long. (historical note: see 1ef04fefe2241087d9db7e9615c3f11b516e36cf) Signed-off-by: NeilBrown <neilb@suse.de> Reported-by: Jiri Slaby <jslaby@suse.cz> and many others
2010-08-18md: provide appropriate return value for spare_active functions.NeilBrown
md_check_recovery expects ->spare_active to return 'true' if any spares were activated, but none of them do, so the consequent change in 'degraded' is not notified through sysfs. So count the number of spares activated, subtract it from 'degraded' just once, and return it. Reported-by: Adrian Drzewiecki <adriand@vmware.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-18md: Notify sysfs when RAID1/5/10 disk is In_sync.Adrian Drzewiecki
When RAID1 is done syncing disks, it'll update the state of synced rdevs to In_sync. But it neglected to notify sysfs that the attribute changed. So any programs that are waiting for an rdev's state to change will not be woken. (raid5/raid10 added by neilb) Signed-off-by: Adrian Drzewiecki <adriand@vmware.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-07block: unify flags for struct bio and struct requestChristoph Hellwig
Remove the current bio flags and reuse the request flags for the bio, too. This allows to more easily trace the type of I/O from the filesystem down to the block driver. There were two flags in the bio that were missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've renamed two request flags that had a superflous RW in them. Note that the flags are in bio.h despite having the REQ_ name - as blkdev.h includes bio.h that is the only way to go for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-22Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linusNeilBrown
Conflicts: drivers/md/md.c - Resolved conflict in md_update_sb - Added extra 'NULL' arg to new instance of sysfs_get_dirent. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: Fix read balancing in RAID1 and RAID10 on drives > 2TBNeilBrown
read_balance uses a "unsigned long" for a sector number which will get truncated beyond 2TB. This will cause read-balancing to be non-optimal, and can cause data to be read from the 'wrong' branch during a resync. This has a very small chance of returning wrong data. Reported-by: Jordan Russell <jr-list-2010@quo.to> Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid1: improve printk messagesNeilBrown
Make sure the array name is included in a uniform way in all printk messages. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid1: delay reads that could overtake behind-writes.NeilBrown
When a raid1 array is configured to support write-behind on some devices, it normally only reads from other devices. If all devices are write-behind (because the rest have failed) it is possible for a read request to be serviced before a behind-write request, which would appear as data corruption. So when forced to read from a WriteMostly device, wait for any write-behind to complete, and don't start any more behind-writes. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid1: fix confusing 'redirect sector' message.NeilBrown
This message seems to suggest the named device is the one on which a read failed, however it is actually the device that the read will be redirected to. So make the message a little clearer. Reported-by: Tim Burgess <ozburgess@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: pass mddev to make_request functions rather than request_queueNeilBrown
We used to pass the personality make_request function direct to the block layer so the first argument had to be a queue. But now we have the intermediary md_make_request so it makes at lot more sense to pass a struct mddev_s. It makes it possible to have an mddev without its own queue too. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: remove ->changed and related code.NeilBrown
We set ->changed to 1 and call check_disk_change at the end of md_open so that bd_invalidated would be set and thus partition rescan would happen appropriately. Now that we call revalidate_disk directly, which sets bd_invalidates, that indirection is no longer needed and can be removed. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: move io accounting out of personalities into md_make_requestNeilBrown
While I generally prefer letting personalities do as much as possible, given that we have a central md_make_request anyway we may as well use it to simplify code. Also this centralises knowledge of ->gendisk which will help later. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18drivers/md: Remove unnecessary casts of void *H Hartley Sweeten
void pointers do not need to be cast to other pointer types. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid1: fix counting of write targets.NeilBrown
There is a very small race window when writing to a RAID1 such that if a device is marked faulty at exactly the wrong time, the write-in-progress will not be sent to the device, but the bitmap (if present) will be updated to say that the write was sent. Then if the device turned out to still be usable as was re-added to the array, the bitmap-based-resync would skip resyncing that block, possibly leading to corruption. This would only be a problem if no further writes were issued to that area of the device (i.e. that bitmap chunk). Suitable for any pending -stable kernel. Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-16md: deal with merge_bvec_fn in component devices better.NeilBrown
If a component device has a merge_bvec_fn then as we never call it we must ensure we never need to. Currently this is done by setting max_sector to 1 PAGE, however this does not stop a bio being created with several sub-page iovecs that would violate the merge_bvec_fn. So instead set max_segments to 1 and set the segment boundary to the same as a page boundary to ensure there is only ever one single-page segment of IO requested at a time. This can particularly be an issue when 'xen' is used as it is known to submit multiple small buffers in a single bio. Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2010-02-26block: Rename blk_queue_max_sectors to blk_queue_max_hw_sectorsMartin K. Petersen
The block layer calling convention is blk_queue_<limit name>. blk_queue_max_sectors predates this practice, leading to some confusion. Rename the function to appropriately reflect that its intended use is to set max_hw_sectors. Also introduce a temporary wrapper for backwards compability. This can be removed after the merge window is closed. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-12-14md: add MODULE_DESCRIPTION for all md related modules.NeilBrown
Suggested by Oren Held <orenhe@il.ibm.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: move offset, daemon_sleep and chunksize out of bitmap structureNeilBrown
... and into bitmap_info. These are all configuration parameters that need to be set before the bitmap is created. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md/raid1: add takeover support for raid5->raid1NeilBrown
A 2-device raid5 array can now be converted to raid1. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: add honouring of suspend_{lo,hi} to raid1.NeilBrown
This will allow us to stop writeout to portions of the array while they are resynced by someone else - e.g. another node in a cluster. Signed-off-by: NeilBrown <neilb@suse.de>