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path: root/drivers/md/raid1.c
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2011-07-28md/raid1: factor several functions out or raid1d()NeilBrown
raid1d is too big with several deep branches. So separate them out into their own functions. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md/raid1: improve handling of read failure during recovery.NeilBrown
If we cannot read a block from anywhere during recovery, there is now a better approach than just giving up. We can record a bad block on each device and keep going - being careful not to clear the bad block when a write succeeds as it might - it will be a write of incorrect data. We have now reached the state where - for raid1 - we only call md_error if md_set_badblocks has failed. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md/raid1: record badblocks found during resync etc.NeilBrown
If we find a bad block while writing as part of resync/recovery we need to report that back to raid1d which must record the bad block, or fail the device. Similarly when fixing a read error, a further error should just record a bad block if possible rather than failing the device. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md/raid1: Handle write errors by updating badblock log.NeilBrown
When we get a write error (in the data area, not in metadata), update the badblock log rather than failing the whole device. As the write may well be many blocks, we trying writing each block individually and only log the ones which fail. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md/raid1: store behind-write pages in bi_vecs.NeilBrown
When performing write-behind we allocate pages to store the data during write. Previously we just keep a list of pages. Now we keep a list of bi_vec which includes offset and size. This means that the r1bio has complete information to create a new bio which will be needed for retrying after write errors. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md/raid1: clear bad-block record when write succeeds.NeilBrown
If we succeed in writing to a block that was recorded as being bad, we clear the bad-block record. This requires some delayed handling as the bad-block-list update has to happen in process-context. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md/raid1: avoid writing to known-bad blocks on known-bad drives.NeilBrown
If we have seen any write error on a drive, then don't write to any known-bad blocks on that drive. If necessary, we divide the write request up into pieces just like we do for reads, so each piece is either all written or all not written to any given drive. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md: make it easier to wait for bad blocks to be acknowledged.NeilBrown
It is only safe to choose not to write to a bad block if that bad block is safely recorded in metadata - i.e. if it has been 'acknowledged'. If it hasn't we need to wait for the acknowledgement. We support that using rdev->blocked wait and md_wait_for_blocked_rdev by introducing a new device flag 'BlockedBadBlock'. This flag is only advisory. It is cleared whenever we acknowledge a bad block, so that a waiter can re-check the particular bad blocks that it is interested it. It should be set by a caller when they find they need to wait. This (set after test) is inherently racy, but as md_wait_for_blocked_rdev already has a timeout, losing the race will have minimal impact. When we clear "Blocked" was also clear "BlockedBadBlocks" incase it was set incorrectly (see above race). We also modify the way we manage 'Blocked' to fit better with the new handling of 'BlockedBadBlocks' and to make it consistent between externally managed and internally managed metadata. This requires that each raidXd loop checks if the metadata needs to be written and triggers a write (md_check_recovery) if needed. Otherwise a queued write request might cause raidXd to wait for the metadata to write, and only that thread can write it. Before writing metadata, we set FaultRecorded for all devices that are Faulty, then after writing the metadata we clear Blocked for any device for which the Fault was certainly Recorded. The 'faulty' device flag now appears in sysfs if the device is faulty *or* it has unacknowledged bad blocks. So user-space which does not understand bad blocks can continue to function correctly. User space which does, should not assume a device is faulty until it sees the 'faulty' flag, and then sees the list of unacknowledged bad blocks is empty. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid1: avoid reading known bad blocks during resyncNeilBrown
When performing resync/etc, keep the size of the request small enough that it doesn't overlap any known bad blocks. Devices with badblocks at the start of the request are completely excluded. If there is nowhere to read from due to bad blocks, record a bad block on each target device. Now that we never read from known-bad-blocks we can allow devices with known-bad-blocks into a RAID1. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid1: avoid reading from known bad blocks.NeilBrown
Now that we have a bad block list, we should not read from those blocks. There are several main parts to this: 1/ read_balance needs to check for bad blocks, and return not only the chosen device, but also how many good blocks are available there. 2/ fix_read_error needs to avoid trying to read from bad blocks. 3/ read submission must be ready to issue multiple reads to different devices as different bad blocks on different devices could mean that a single large read cannot be served by any one device, but can still be served by the array. This requires keeping count of the number of outstanding requests per bio. This count is stored in 'bi_phys_segments' 4/ retrying a read needs to also be ready to submit a smaller read and queue another request for the rest. This does not yet handle bad blocks when reading to perform resync, recovery, or check. 'md_trim_bio' will also be used for RAID10, so put it in md.c and export it. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md: don't allow arrays to contain devices with bad blocks.NeilBrown
As no personality understand bad block lists yet, we must reject any device that is known to contain bad blocks. As the personalities get taught, these tests can be removed. This only applies to raid1/raid5/raid10. For linear/raid0/multipath/faulty the whole concept of bad blocks doesn't mean anything so there is no point adding the checks. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27MD: raid1 s/sysfs_notify_dirent/sysfs_notify_dirent_safeJonathan Brassow
If device-mapper creates a RAID1 array that includes devices to be rebuilt, it will deref a NULL pointer when finished because sysfs is not used by device-mapper instantiated RAID devices. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27md/raid1: move rdev->corrected_errors countingNamhyung Kim
Read errors are considered to corrected if write-back and re-read cycle is finished without further problems. Thus moving the rdev-> corrected_errors counting after the re-reading looks more reasonable IMHO. Also included a couple of whitespace fixes on sync_page_io(). Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27md: change managed of recovery_disabled.NeilBrown
If we hit a read error while recovering a mirror, we want to abort the recovery without necessarily failing the disk - as having a disk this a read error is better than not having an array at all. Currently this is managed with a per-array flag "recovery_disabled" and is only implemented for RAID1. For RAID10 we will need finer grained control as we might want to disable recovery for individual devices separately. So push more of the decision making into the personality. 'recovery_disabled' is now a 'cookie' which is copied when the personality want to disable recovery and is changed when a device is added to the array as this is used as a trigger to 'try recovery again'. This will allow RAID10 to get the control that it needs. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27md: introduce link/unlink_rdev() helpersNamhyung Kim
There are places where sysfs links to rdev are handled in a same way. Add the helper functions to consolidate them. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27md/raid: use printk_ratelimited instead of printk_ratelimitChristian Dietrich
As per printk_ratelimit comment, it should not be used. Signed-off-by: Christian Dietrich <christian.dietrich@informatik.uni-erlangen.de> Signed-off-by: NeilBrown <neilb@suse.de>
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>