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2011-07-28md: add 'write_error' flag to component devices.NeilBrown
If a device has ever seen a write error, we will want to handle known-bad-blocks differently. So create an appropriate state flag and export it via sysfs. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
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: Disable bad blocks and v0.90 metadata.NeilBrown
v0.90 metadata cannot record bad blocks, so when loading metadata for such a device, set shift to -1. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md: load/store badblock list from v1.x metadataNeilBrown
Space must have been allocated when array was created. A feature flag is set when the badblock list is non-empty, to ensure old kernels don't load and trust the whole device. We only update the on-disk badblocklist when it has changed. If the badblocklist (or other metadata) is stored on a bad block, we don't cope very well. If metadata has no room for bad block, flag bad-blocks as disabled, and do the same for 0.90 metadata. 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>
2011-07-28md/bad-block-log: add sysfs interface for accessing bad-block-log.NeilBrown
This can show the log (providing it fits in one page) and allows bad blocks to be 'acknowledged' meaning that they have safely been recorded in metadata. Clearing bad blocks is not allowed via sysfs (except for code testing). A bad block can only be cleared when a write to the block succeeds. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md: beginnings of bad block management.NeilBrown
This the first step in allowing md to track bad-blocks per-device so that we can fail individual blocks rather than the whole device. This patch just adds a data structure for recording bad blocks, with routines to add, remove, search the list. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28md: remove suspicious size_of()NeilBrown
When calling bioset_create we pass the size of the front_pad as sizeof(mddev) which looks suspicious as mddev is a pointer and so it looks like a common mistake where sizeof(*mddev) was intended. The size is actually correct as we want to store a pointer in the front padding of the bios created by the bioset, so make the intent more explicit by using sizeof(mddev_t *) Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27MD: generate an event when array sync is completeJonathan Brassow
This patch causes MD to generate an event (for device-mapper) when the synchronization thread is reaped. This is expected behavior for device-mapper. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27MD bitmap: Revert DM dirty log hooksJonathan Brassow
Revert most of commit e384e58549a2e9a83071ad80280c1a9053cfd84c md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log. MD should not need to use DM's dirty log - we decided to use md's bitmaps instead. Keeping the DIV_ROUND_UP clean-ups that were part of commit e384e58549a2e9a83071ad80280c1a9053cfd84c, however. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
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/raid5: Avoid BUG caused by multiple failures.NeilBrown
While preparing to write a stripe we keep the parity block or blocks locked (R5_LOCKED) - towards the end of schedule_reconstruction. If the array is discovered to have failed before this write completes we can leave those blocks LOCKED, and init_stripe will notice that a free stripe still has a locked block and will complain. So clear the R5_LOCKED flag in handle_failed_stripe, and demote the 'BUG' to a 'WARN_ON'. Signed-off-by: NeilBrown <neilb@suse.de>
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/raid5: 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/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: get rid of unnecessary casts on page_address()Namhyung Kim
page_address() returns void pointer, so the casts can be removed. 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: 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: remove ro check in md_check_recovery()Namhyung Kim
Commit c89a8eee6154 ("Allow faulty devices to be removed from a readonly array.") added some work on ro array in the function, but it couldn't be done since we didn't allow the ro array to be handled from the beginning. Fix it. Signed-off-by: Namhyung Kim <namhyung@gmail.com> 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>
2011-07-27md: use proper little-endian bitopsAkinobu Mita
Using __test_and_{set,clear}_bit_le() with ignoring its return value can be replaced with __{set,clear}_bit_le(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: NeilBrown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27md/raid5: finalise new merged handle_stripe.NeilBrown
handle_stripe5() and handle_stripe6() are now virtually identical. So discard one and rename the other to 'analyse_stripe()'. It always returns 0, so change it to 'void' and remove the 'done' variable in handle_stripe(). Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: move some more common code into handle_stripeNeilBrown
The RAID6 version of this code is usable for RAID5 providing: - we test "conf->max_degraded" rather than "2" as appropriate - we make sure s->failed_num[1] is meaningful (and not '-1') when s->failed > 1 The 'return 1' must become 'goto finish' in the new location. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: move more common code into handle_stripeNeilBrown
Apart from 'prexor' which can only be set for RAID5, and 'qd_idx' which can only be meaningful for RAID6, these two chunks of code are nearly the same. So combine them into one adding a test to call either handle_parity_checks5 or handle_parity_checks6 as appropriate. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: unite handle_stripe_dirtying5 and handle_stripe_dirtying6NeilBrown
RAID6 is only allowed to choose 'reconstruct-write' while RAID5 is also allow 'read-modify-write' Apart from this difference, handle_stripe_dirtying[56] are nearly identical. So resolve these differences and create just one function. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: unite fetch_block5 and fetch_block6NeilBrown
Provided that ->failed_num[1] is not a valid device number (which is easily achieved) fetch_block6 provides all the functionality of fetch_block5. So remove the latter and rename the former to simply "fetch_block". Then handle_stripe_fill5 and handle_stripe_fill6 become the same and can similarly be united. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: rearrange a test in fetch_block6.NeilBrown
Next patch will unite fetch_block5 and fetch_block6. First I want to make the differences a little more clear. For RAID6 if we are writing at all and there is a failed device, then we need to load or compute every block so we can do a reconstruct-write. This case isn't needed for RAID5 - we will do a read-modify-write in that case. So make that test a separate test in fetch_block6 rather than merged with two other tests. Make a similar change in fetch_block5 so the one bit that is not needed for RAID6 is clearly separate. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: move more code into common handle_stripeNeilBrown
The difference between the RAID5 and RAID6 code here is easily resolved using conf->max_degraded. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: Move code for finishing a reconstruction into handle_stripe.NeilBrown
Prior to commit ab69ae12ceef7 the code in handle_stripe5 and handle_stripe6 to "Finish reconstruct operations initiated by the expansion process" was identical. That commit added an identical stanza of code to each function, but in different places. That was careless. The raid5 code was correct, so move that out into handle_stripe and remove raid6 version. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27md/raid5: Remove stripe_head_state arg from handle_stripe_expansion.NeilBrown
This arg is only used to differentiate between RAID5 and RAID6 but that is not needed. For RAID5, raid5_compute_sector will set qd_idx to "~0" so j with certainly not equals qd_idx, so there is no need for a guard on that condition. So remove the guard and remove the arg from the declaration and callers of handle_stripe_expansion. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26md/raid5: move stripe_head_state and more code into handle_stripe.NeilBrown
By defining the 'stripe_head_state' in 'handle_stripe', we can move some common code out of handle_stripe[56]() and into handle_stripe. The means that all accesses for stripe_head_state in handle_stripe[56] need to be 's->' instead of 's.', but the compiler should inline those functions and just use a direct stack reference, and future patches while hoist most of this code up into handle_stripe() so we will revert to "s.". Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26md/raid5: add some more fields to stripe_head_stateNeilBrown
Adding these three fields will allow more common code to be moved to handle_stripe() struct field rearrangement by Namhyung Kim. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26md/raid5: unify stripe_head_state and r6_stateNeilBrown
'struct stripe_head_state' stores state about the 'current' stripe that is passed around while handling the stripe. For RAID6 there is an extension structure: r6_state, which is also passed around. There is no value in keeping these separate, so move the fields from the latter into the former. This means that all code now needs to treat s->failed_num as an small array, but this is a small cost. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26md/raid5: move common code into handle_stripeNeilBrown
There is common code at the start of handle_stripe5 and handle_stripe6. Move it into handle_stripe. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26md/raid5: replace sh->lock with an 'active' flag.NeilBrown
sh->lock is now mainly used to ensure that two threads aren't running in the locked part of handle_stripe[56] at the same time. That can more neatly be achieved with an 'active' flag which we set while running handle_stripe. If we find the flag is set, we simply requeue the stripe for later by setting STRIPE_HANDLE. For safety we take ->device_lock while examining the state of the stripe and creating a summary in 'stripe_head_state / r6_state'. This possibly isn't needed but as shared fields like ->toread, ->towrite are checked it is safer for now at least. We leave the label after the old 'unlock' called "unlock" because it will disappear in a few patches, so renaming seems pointless. This leaves the stripe 'locked' for longer as we clear STRIPE_ACTIVE later, but that is not a problem. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26md/raid5: Protect some more code with ->device_lock.NeilBrown
Other places that change or follow dev->towrite and dev->written take the device_lock as well as the sh->lock. So it should really be held in these places too. Also, doing so will allow sh->lock to be discarded. with merged fixes by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26md/raid5: Remove use of sh->lock in sync_requestNeilBrown
This is the start of a series of patches to remove sh->lock. sync_request takes sh->lock before setting STRIPE_SYNCING to ensure there is no race with testing it in handle_stripe[56]. Instead, use a new flag STRIPE_SYNC_REQUESTED and test it early in handle_stripe[56] (after getting the same lock) and perform the same set/clear operations if it was set. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-18md/raid5: get rid of duplicated call to bio_data_dir()Namhyung Kim
In raid5::make_request(), once bio_data_dir(@bi) is detected it never (and couldn't) be changed. Use the result always. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18md/raid5: use kmem_cache_zalloc()Namhyung Kim
Replace kmem_cache_alloc + memset(,0,) to kmem_cache_zalloc. I think it's not harmful since @conf->slab_cache already knows actual size of struct stripe_head. Signed-off-by: Namhyung Kim <namhyung@gmail.com> 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>
2011-06-28md: avoid endless recovery loop when waiting for fail device to complete.NeilBrown
If a device fails in a way that causes pending request to take a while to complete, md will not be able to immediately remove it from the array in remove_and_add_spares. It will then incorrectly look like a spare device and md will try to recover it even though it is failed. This leads to a recovery process starting and instantly aborting over and over again. We should check if the device is faulty before considering it to be a spare. This will avoid trying to start a recovery that cannot proceed. This bug was introduced in 2.6.26 so that patch is suitable for any kernel since then. Cc: stable@kernel.org Reported-by: Jim Paradis <james.paradis@stratus.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-14md/raid5: remove unusual use of bio_iovec_idx()Namhyung Kim
In the bio_for_each_segment loop, bvl always points current bio_vec, so the same as bio_iovec_idx(, i). Let's get rid of it. Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-14md/raid5: fix FUA request handling in ops_run_io()Namhyung Kim
Commit e9c7469bb4f5 ("md: implment REQ_FLUSH/FUA support") introduced R5_WantFUA flag and set rw to WRITE_FUA in that case. However remaining code still checks whether rw is exactly same as WRITE or not, so FUAed-write ends up with being treated as READ. Fix it. This bug has been present since 2.6.37 and the fix is suitable for any -stable kernel since then. It is not clear why this has not caused more problems. Cc: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-14md/raid5: fix raid5_set_bi_hw_segmentsNamhyung Kim
The @bio->bi_phys_segments consists of active stripes count in the lower 16 bits and processed stripes count in the upper 16 bits. So logical-OR operator should be bitwise one. This bug has been present since 2.6.27 and the fix is suitable for any -stable kernel since then. Fortunately the bad code is only used on error paths and is relatively unlikely to be hit. Cc: stable@kernel.org Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09md/bitmap: remove unused fields from struct bitmapNamhyung Kim
Get rid of ->syncchunk and ->counter_bits since they're never used. Also discard COUNTER_BYTE_RATIO which is unused. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>