- 28 Jul, 2011 33 commits
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NeilBrown authored
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>
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NeilBrown authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
raid10d() is too big and is about to get bigger, so split handle_read_error() out as a separate function. Signed-off-by: -
NeilBrown authored
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 authored
On a successful write to a known bad block, flag the sh so that raid5d can remove the known bad block from the list. Signed-off-by: -
NeilBrown authored
If a device has seen write errors, don't write to any known bad blocks on that device. Signed-off-by: -
NeilBrown authored
When a write error is detected, don't mark the device as failed immediately but rather record the fact for handle_stripe to deal with. Handle_stripe then attempts to record a bad block. Only if that fails does the device get marked as faulty. Signed-off-by: -
NeilBrown authored
If we get an uncorrectable read error - record a bad block rather than failing the device. And if these errors (which may be due to known bad blocks) cause recovery to be impossible, record a bad block on the recovering devices, or abort the recovery. As we might abort a recovery without failing a device we need to teach RAID5 about recovery_disabled handling. Signed-off-by: -
NeilBrown authored
There are two times that we might read in raid5: 1/ when a read request fits within a chunk on a single working device. In this case, if there is any bad block in the range of the read, we simply fail the cache-bypass read and perform the read though the stripe cache. 2/ when reading into the stripe cache. In this case we mark as failed any device which has a bad block in that strip (1 page wide). Note that we will both avoid reading and avoid writing. This is correct (as we will never read from the block, there is no point writing), but not optimal (as writing could 'fix' the error) - that will be addressed later. If we have not seen any write errors on the device yet, we treat a bad block like a recent read error. This will encourage an attempt to fix the read error which will either generate a write error, or will ensure good data is stored there. We don't yet forget the bad block in that case. That comes later. Now that we honour bad blocks when reading we can allow devices with bad blocks into the array. Signed-off-by: -
NeilBrown authored
raid1d is too big with several deep branches. So separate them out into their own functions. Signed-off-by:
Namhyung Kim <namhyung@gmail.com>
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NeilBrown authored
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:
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NeilBrown authored
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:
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NeilBrown authored
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:
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NeilBrown authored
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:
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NeilBrown authored
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:
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NeilBrown authored
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:
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Namhyung Kim authored
Previous patches in the bad block series extended behavior of rdev's 'state' interface but lacked documentation update. Fix it. Signed-off-by:
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NeilBrown authored
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 authored
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:
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NeilBrown authored
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 authored
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 authored
v0.90 metadata cannot record bad blocks, so when loading metadata for such a device, set shift to -1. Signed-off-by: -
NeilBrown authored
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 authored
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:
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Namhyung Kim authored
Previous patch in the bad block series added new sysfs interfaces ([unacknowledged_]bad_blocks) for each rdev without documentation. Add it. Signed-off-by:
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NeilBrown authored
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:
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NeilBrown authored
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:
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- 27 Jul, 2011 7 commits
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NeilBrown authored
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:
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Jonathan Brassow authored
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:
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Jonathan Brassow authored
Revert most of commit e384e585 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 e384e585, however. Signed-off-by:
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Jonathan Brassow authored
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:
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NeilBrown authored
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: -
Namhyung Kim authored
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:
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Namhyung Kim authored
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:
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