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path: root/drivers/md/raid10.c
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2011-10-26md: Fix some bugs in recovery_disabled handling.NeilBrown
In 3.0 we changed the way recovery_disabled was handle so that instead of testing against zero, we test an mddev-> value against a conf-> value. Two problems: 1/ one place in raid1 was missed and still sets to '1'. 2/ We didn't explicitly set the conf-> value at array creation time. It defaulted to '0' just like the mddev value does so they could appear equal and thus disable recovery. This did not affect normal 'md' as it calls bind_rdev_to_array which changes the mddev value. However the dmraid interface doesn't call this and so doesn't change ->recovery_disabled; so at array start all recovery is incorrectly disabled. So initialise the 'conf' value to one less that the mddev value, so the will only be the same when explicitly set that way. Reported-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md: add proper write-congestion reporting to RAID1 and RAID10.NeilBrown
RAID1 and RAID10 handle write requests by queuing them for handling by a separate thread. This is because when a write-intent-bitmap is active we might need to update the bitmap first, so it is good to queue a lot of writes, then do one big bitmap update for them all. However writeback request devices to appear to be congested after a while so it can make some guesstimate of throughput. The infinite queue defeats that (note that RAID5 has already has a finite queue so it doesn't suffer from this problem). So impose a limit on the number of pending write requests. By default it is 1024 which seems to be generally suitable. Make it configurable via module option just in case someone finds a regression. Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md: rename "mdk_personality" to "md_personality"NeilBrown
"mdk" doesn't mean anything any more. Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md/raid10: typedef removal: conf_t -> struct r10confNeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md/raid0: typedef removal: raid0_conf_t -> struct r0confNeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md: remove typedefs: mirror_info_t -> struct mirror_infoNeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md: remove typedefs: r10bio_t -> struct r10bio and r1bio_t -> struct r1bioNeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md: remove typedefs: mddev_t -> struct mddevNeilBrown
Having mddev_t and 'struct mddev_s' is ugly and not preferred Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11md: removing typedefs: mdk_rdev_t -> struct md_rdevNeilBrown
The typedefs are just annoying. 'mdk' probably refers to 'md_k.h' which used to be an include file that defined this thing. Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-21md: Avoid waking up a thread after it has been freed.NeilBrown
Two related problems: 1/ some error paths call "md_unregister_thread(mddev->thread)" without subsequently clearing ->thread. A subsequent call to mddev_unlock will try to wake the thread, and crash. 2/ Most calls to md_wakeup_thread are protected against the thread disappeared either by: - holding the ->mutex - having an active request, so something else must be keeping the array active. However mddev_unlock calls md_wakeup_thread after dropping the mutex and without any certainty of an active request, so the ->thread could theoretically disappear. So we need a spinlock to provide some protections. So change md_unregister_thread to take a pointer to the thread pointer, and ensure that it always does the required locking, and clears the pointer properly. Reported-by: "Moshe Melnikov" <moshe@zadarastorage.com> Signed-off-by: NeilBrown <neilb@suse.de> cc: stable@kernel.org
2011-09-10md/raid1,10: Remove use-after-free bug in make_request.NeilBrown
A single request to RAID1 or RAID10 might result in multiple requests if there are known bad blocks that need to be avoided. To detect if we need to submit another write request we test: if (sectors_handled < (bio->bi_size >> 9)) { However this is after we call **_write_done() so the 'bio' no longer belongs to us - the writes could have completed and the bio freed. So move the **_write_done call until after the test against bio->bi_size. This addresses https://bugzilla.kernel.org/show_bug.cgi?id=41862 Reported-by: Bruno Wolff III <bruno@wolff.to> Tested-by: Bruno Wolff III <bruno@wolff.to> Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10md/raid10: unify handling of write completion.NeilBrown
A write can complete at two different places: 1/ when the last member-device write completes, through raid10_end_write_request 2/ in make_request() when we remove the initial bias from ->remaining. These two should do exactly the same thing and the comment says they do, but they don't. So factor the correct code out into a function and call it in both places. This makes the code much more similar to RAID1. The difference is only significant if there is an error, and they usually take a while, so it is unlikely that there will be an error already when make_request is completing, so this is unlikely to cause real problems. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: handle further errors during fix_read_error better.NeilBrown
If we find more read/write errors we should record a bad block before failing the device. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: Handle read errors during recovery better.NeilBrown
Currently when we get a read error during recovery, we simply abort the recovery. Instead, repeat the read in page-sized blocks. On successful reads, write to the target. On read errors, record a bad block on the destination, and only if that fails do we abort the recovery. As we now retry reads we need to know where we read from. This was in bi_sector but that can be changed during a read attempt. So store the correct from_addr and to_addr in the r10_bio for later access. Signed-off-by: NeilBrown<neilb@suse.de>
2011-07-28md/raid10: simplify read error handling during recovery.NeilBrown
If a read error is detected during recovery the code currently fails the read device. This isn't really necessary. recovery_request_write will signal a write error to end_sync_write and it will record a write error on the destination device which will record a bad block there or kick it from the array. So just remove this call to do md_error. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: record bad blocks due to write errors during resync/recovery.NeilBrown
If we get a write error during resync/recovery don't fail the device but instead record a bad block. If that fails we can then fail the device. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: attempt to fix read errors during resync/checkNeilBrown
We already attempt to fix read errors found during normal IO and a 'repair' process. It is best to try to repair them at any time they are found, so move a test so that during sync and check a read error will be corrected by over-writing with good data. If both (all) devices have known bad blocks in the sync section we won't try to fix even though the bad blocks might not overlap. That should be considered later. Also if we hit a read error during recovery we don't try to fix it. It would only be possible to fix if there were at least three copies of data, which is not very common with RAID10. But it should still be considered later. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: 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>
2011-07-28md/raid10: 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>
2011-07-28md/raid10: avoid writing to known bad blocks on known bad drives.NeilBrown
Writing to known bad blocks on drives that have seen a write error is asking for trouble. So try to avoid these blocks. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10 record bad blocks as needed during recovery.NeilBrown
When recovering one or more devices, if all the good devices have bad blocks we should record a bad block on the device being rebuilt. If this fails, we need to abort the recovery. To ensure we don't think that we aborted later than we actually did, we need to move the check for MD_RECOVERY_INTR earlier in md_do_sync, in particular before mddev->curr_resync is updated. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: avoid reading known bad blocks during resync/recovery.NeilBrown
During resync/recovery limit the size of the request to avoid reading into a bad block that does not start at-or-before the current read address. Similarly if there is a bad block at this address, don't allow the current request to extend beyond the end of that bad block. Now that we don't ever read from known bad blocks, it is safe to allow devices with those blocks into the array. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10 - avoid reading from known bad blocks - part 3NeilBrown
When attempting to repair a read error, don't read from devices with a known bad block. As we are only reading PAGE_SIZE blocks, we don't try to narrow down to smaller regions in the hope that only part of this page is bad - it isn't worth the effort. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: avoid reading from known bad blocks - part 2NeilBrown
When redirecting a read error to a different device, we must again avoid bad blocks and possibly split the request. Spin_lock typo fixed thanks to Dan Carpenter <error27@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: avoid reading from known bad blocks - part 1NeilBrown
This patch just covers the basic read path: 1/ read_balance needs to check for badblocks, and return not only the chosen slot, but also how many good blocks are available there. 2/ 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' On read error we currently just fail the request if another target cannot handle the whole request. Next patch refines that a bit. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: Split handle_read_error out from raid10d.NeilBrown
raid10d() is too big and is about to get bigger, so split handle_read_error() out as a separate function. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md/raid10: simplify/reindent some loops.NeilBrown
When a loop ends with a large if, it can be neater to change the if to invert the condition and just 'continue'. Then the body of the if can be indented to a lower level. Signed-off-by: NeilBrown <neilb@suse.de>
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: 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/raid10: 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. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27md/raid10: Improve decision on whether to fail a device with a read error.NeilBrown
Normally we would fail a device with a READ error. However if doing so causes the array to fail, it is better to leave the device in place and just return the read error to the caller. The current test for decide if the array will fail is overly simplistic. We have a function 'enough' which can tell if the array is failed or not, so use it to guide the decision. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27md/raid10: Make use of new recovery_disabled handlingNeilBrown
When we get a read error during recovery, RAID10 previously arranged for the recovering device to appear to fail so that the recovery stops and doesn't restart. This is misleading and wrong. Instead, make use of the new recovery_disabled handling and mark the target device and having recovery disabled. Add appropriate checks in add_disk and remove_disk so that devices are removed and not re-added when recovery is disabled. 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>
2011-07-18md/raid10: share pages between read and write bio's during recoveryNamhyung Kim
When performing a recovery, only first 2 slots in r10_bio are in use, for read and write respectively. However all of pages in the write bio are never used and just replaced to read bio's when the read completes. Get rid of those unused pages and share read pages properly. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18md/raid10: factor out common bio handling codeNamhyung Kim
When normal-write and sync-read/write bio completes, we should find out the disk number the bio belongs to. Factor those common code out to a separate function. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18md/raid10: get rid of duplicated conditional expressionNamhyung Kim
Variable 'first' is initialized to zero and updated to @rdev->raid_disk only if it is greater than 0. Thus condition '>= first' always implies '>= 0' so the latter is not needed. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid10: reformat some loops with less indenting.NeilBrown
When a loop ends with an 'if' with a large body, it is neater to make the if 'continue' on the inverse condition, and then the body is indented less. Apply this pattern 3 times, and wrap some other long lines. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid10: remove unused variable.NeilBrown
This variable 'disk' is never used - how odd. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid10: make more use of 'slot' in raid10d.NeilBrown
Now that we have a 'slot' variable, make better use of it to simplify some code a little. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md/raid10: some tidying up in fix_read_errorNeilBrown
Currently the rdev on which a read error happened could be removed before we perform the fix_error handling. This requires extra tests for NULL. So delay the rdev_dec_pending call until after the call to fix_read_error so that we can be sure that the rdev still exists. This allows an 'if' clause to be removed so the body gets re-indented back one level. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md: simplify raid10 read_balanceNeilBrown
raid10 read balance has two different loop for looking through possible devices to chose the best. Collapse those into one loop and generally make the code more readable. 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>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
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>
2011-02-08FIX: md: process hangs at wait_barrier after 0->10 takeoverKrzysztof Wojcik
Following symptoms were observed: 1. After raid0->raid10 takeover operation we have array with 2 missing disks. When we add disk for rebuild, recovery process starts as expected but it does not finish- it stops at about 90%, md126_resync process hangs in "D" state. 2. Similar behavior is when we have mounted raid0 array and we execute takeover to raid10. After this when we try to unmount array- it causes process umount hangs in "D" In scenarios above processes hang at the same function- wait_barrier in raid10.c. Process waits in macro "wait_event_lock_irq" until the "!conf->barrier" condition will be true. In scenarios above it never happens. Reason was that at the end of level_store, after calling pers->run, we call mddev_resume. This calls pers->quiesce(mddev, 0) with RAID10, that calls lower_barrier. However raise_barrier hadn't been called on that 'conf' yet, so conf->barrier becomes negative, which is bad. This patch introduces setting conf->barrier=1 after takeover operation. It prevents to become barrier negative after call lower_barrier(). Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com> 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>