- 27 Mar, 2006 12 commits
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NeilBrown authored
raid5 overloads bi_phys_segments to count the number of blocks that the request was broken in to so that it knows when the bio is completely handled. Accessing this must always be done under a spinlock. In one case we also call bi_end_io under that spinlock, which probably isn't ideal as bi_end_io could be expensive (even though it isn't allowed to sleep). So we reducde the range of the spinlock to just accessing bi_phys_segments. Signed-off-by:
Neil Brown <neilb@suse.de> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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NeilBrown authored
wait_event_lock_irq puts a ';' after its usage of the 4th arg, so we don't need to. Signed-off-by:
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NeilBrown authored
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NeilBrown authored
This allows user-space to access data safely. This is needed for raid5 reshape as user-space needs to take a backup of the first few stripes before allowing reshape to commence. It will also be useful in cluster-aware raid1 configurations so that all cluster members can leave a section of the array untouched while a resync/recovery happens. A 'start' and 'end' of the suspended range are written to 2 sysfs attributes. Note that only one range can be suspended at a time. Signed-off-by:
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NeilBrown authored
check_reshape checks validity and does things that can be done instantly - like adding devices to raid1. start_reshape initiates a restriping process to convert the whole array. Signed-off-by:
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NeilBrown authored
Instead of checkpointing at each stripe, only checkpoint when a new write would overwrite uncheckpointed data. Block any write to the uncheckpointed area. Arbitrarily checkpoint at least every 3Meg. Signed-off-by:
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NeilBrown authored
We allow the superblock to record an 'old' and a 'new' geometry, and a position where any conversion is up to. The geometry allows for changing chunksize, layout and level as well as number of devices. When using verion-0.90 superblock, we convert the version to 0.91 while the conversion is happening so that an old kernel will refuse the assemble the array. For version-1, we use a feature bit for the same effect. When starting an array we check for an incomplete reshape and restart the reshape process if needed. If the reshape stopped at an awkward time (like when updating the first stripe) we refuse to assemble the array, and let user-space worry about it. Signed-off-by:
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NeilBrown authored
This patch adds raid5_reshape and end_reshape which will start and finish the reshape processes. raid5_reshape is only enabled in CONFIG_MD_RAID5_RESHAPE is set, to discourage accidental use. Read the 'help' for the CONFIG_MD_RAID5_RESHAPE entry. and Make sure that you have backups, just in case. Signed-off-by:
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NeilBrown authored
This patch provides the core of the resize/expand process. sync_request notices if a 'reshape' is happening and acts accordingly. It allocated new stripe_heads for the next chunk-wide-stripe in the target geometry, marking them STRIPE_EXPANDING. Then it finds which stripe heads in the old geometry can provide data needed by these and marks them STRIPE_EXPAND_SOURCE. This causes stripe_handle to read all blocks on those stripes. Once all blocks on a STRIPE_EXPAND_SOURCE stripe_head are read, any that are needed are copied into the corresponding STRIPE_EXPANDING stripe_head. Once a STRIPE_EXPANDING stripe_head is full, it is marks STRIPE_EXPAND_READY and then is written out and released. Signed-off-by:
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NeilBrown authored
We need to allow that different stripes are of different effective sizes, and use the appropriate size. Also, when a stripe is being expanded, we must block any IO attempts until the stripe is stable again. Key elements in this change are: - each stripe_head gets a 'disk' field which is part of the key, thus there can sometimes be two stripe heads of the same area of the array, but covering different numbers of devices. One of these will be marked STRIPE_EXPANDING and so won't accept new requests. - conf->expand_progress tracks how the expansion is progressing and is used to determine whether the target part of the array has been expanded yet or not. Signed-off-by:
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NeilBrown authored
Before a RAID-5 can be expanded, we need to be able to expand the stripe-cache data structure. This requires allocating new stripes in a new kmem_cache. If this succeeds, we copy cache pages over and release the old stripes and kmem_cache. We then allocate new pages. If that fails, we leave the stripe cache at it's new size. It isn't worth the effort to shrink it back again. Unfortuanately this means we need two kmem_cache names as we, for a short period of time, we have two kmem_caches. So they are raid5/%s and raid5/%s-alt Signed-off-by:
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NeilBrown authored
The remainder of this batch implements raid5 reshaping. Currently the only shape change that is supported is added a device, but it is envisioned that changing the chunksize and layout will also be supported, as well as changing the level (e.g. 1->5, 5->6). The reshape process naturally has to move all of the data in the array, and so should be used with caution. It is believed to work, and some testing does support this, but wider testing would be great for increasing my confidence. You will need a version of mdadm newer than 2.3.1 to make use of raid5 growth. This is because mdadm need to take a copy of a 'critical section' at the start of the array incase there is a crash at an awkward moment. On restart, mdadm will restore the critical section and allow reshape to continue. I hope to release a 2.4-pre by early next week - it still needs a little more polishing. This patch: Previously the array of disk information was included in the raid5 'conf' structure which was allocated to an appropriate size. This makes it awkward to change the size of that array. So we split it off into a separate kmalloced array which will require a little extra indexing, but is much easier to grow. Signed-off-by:
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- 03 Feb, 2006 1 commit
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NeilBrown authored
- version-1 superblock + The default_bitmap_offset is in sectors, not bytes. + the 'size' field in the superblock is in sectors, not KB - raid0_run should return a negative number on error, not '1' - raid10_read_balance should not return a valid 'disk' number if ->rdev turned out to be NULL - kmem_cache_destroy doesn't like being passed a NULL. Signed-off-by:
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- 15 Jan, 2006 1 commit
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Arjan van de Ven authored
Remove the "inline" keyword from a bunch of big functions in the kernel with the goal of shrinking it by 30kb to 40kb Signed-off-by:
Arjan van de Ven <arjan@infradead.org> Signed-off-by:
Ingo Molnar <mingo@elte.hu> Acked-by:
Jeff Garzik <jgarzik@pobox.com> Signed-off-by:
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- 06 Jan, 2006 10 commits
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NeilBrown authored
Store this total in superblock (As appropriate), and make it available to userspace via sysfs. Signed-off-by:
Greg KH <greg@kroah.com> Signed-off-by:
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NeilBrown authored
Signed-off-by:
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NeilBrown authored
md supports multiple different RAID level, each being implemented by a 'personality' (which is often in a separate module). These personalities have fairly artificial 'numbers'. The numbers are use to: 1- provide an index into an array where the various personalities are recorded 2- identify the module (via an alias) which implements are particular personality. Neither of these uses really justify the existence of personality numbers. The array can be replaced by a linked list which is searched (array lookup only happens very rarely). Module identification can be done using an alias based on level rather than 'personality' number. The current 'raid5' modules support two level (4 and 5) but only one personality. This slight awkwardness (which was handled in the mapping from level to personality) can be better handled by allowing raid5 to register 2 personalities. With this change in place, the core md module does not need to have an exhaustive list of all possible personalities, so other personalities can be added independently. This patch also moves the check for chunksize being non-zero into the ->run routines for the personalities that need it, rather than having it in core-md. This has a side effect of allowing 'faulty' and 'linear' not to have a chunk-size set. Signed-off-by: -
NeilBrown authored
- replace open-coded hash chain with hlist macros - Fix hash-table size at one page - it is already quite generous, so there will never be a need to use multiple pages, so no need for __get_free_pages No functional change. Signed-off-by:
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NeilBrown authored
Replace multiple kmalloc/memset pairs with kzalloc calls. Signed-off-by:
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NeilBrown authored
Substitute: page_cache_get -> get_page page_cache_release -> put_page PAGE_CACHE_SHIFT -> PAGE_SHIFT PAGE_CACHE_SIZE -> PAGE_SIZE PAGE_CACHE_MASK -> PAGE_MASK __free_page -> put_page because we aren't using the page cache, we are just using pages. Signed-off-by:
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NeilBrown authored
There is this "FIXME" comment with a typo in it!! that been annoying me for days, so I just had to remove it. conf->disks[i].rdev should only be accessed if - we know we hold a reference or - the mddev->reconfig_sem is down or - we have a rcu_readlock handle_stripe was referencing rdev in three places without any of these. For the first two, get an rcu_readlock. For the last, the same access (md_sync_acct call) is made a little later after the rdev has been claimed under and rcu_readlock, if R5_Syncio is set. So just use that access... However R5_Syncio isn't really needed as the 'syncing' variable contains the same information. So use that instead. Issues, comment, and fix are identical in raid5 and raid6. Signed-off-by:
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NeilBrown authored
This is important because bitmap_create uses mddev->resync_max_sectors and that doesn't have a valid value until after the array has been initialised (with pers->run()). [It doesn't make a difference for current personalities that support bitmaps, but will make a difference for raid10] This has the added advantage of meaning with can move the thread->timeout manipulation inside the bitmap.c code instead of sprinkling identical code throughout all personalities. Signed-off-by:
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NeilBrown authored
See patch to md.txt for more details Signed-off-by:
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NeilBrown authored
Resync code: A test that isn't needed, a 'compute_block' that makes more sense elsewhere (And then doesn't need a test), a couple of BUG_ONs to confirm the change makes sense. Printks: A few were missing KERN_* Also fix a typo in a comment.. Signed-off-by:
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- 12 Dec, 2005 1 commit
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NeilBrown authored
The raid5 stripe cache was recently changed from fixed size (NR_STRIPES) to variable size (conf->max_nr_stripes). However there are two places that still use the constant and as a result, reducing the size of the stripe cache can result in a deadlock. Signed-off-by:
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- 28 Nov, 2005 1 commit
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NeilBrown authored
bitmap_unplug actually writes data (bits) to storage, so we shouldn't be holding a spinlock... Signed-off-by:
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- 09 Nov, 2005 10 commits
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NeilBrown authored
1/ I really should be using the __ATTR macros for defining attributes, so that the .owner field get set properly, otherwise modules can be removed while sysfs files are open. This also involves some name changes of _show routines. 2/ Always lock the mddev (against reconfiguration) for all sysfs attribute access. This easily avoid certain races and is completely consistant with other interfaces (ioctl and /proc/mdstat both always lock against reconfiguration). 3/ raid5 attributes must check that the 'conf' structure actually exists (the array could have been stopped while an attribute file was open). 4/ A missing 'kfree' from when the raid5_conf_t was converted to have a kobject embedded, and then converted back again. Signed-off-by:
Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by:
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NeilBrown authored
A sync of raid5 usually ignore blocks which the bitmap says are in-sync. But a user-request check or repair should not ignore these. Signed-off-by:
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NeilBrown authored
This has the advantage of removing the confusion caused by 'rdev_t' and 'mddev_t' both having 'in_sync' fields. Signed-off-by:
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NeilBrown authored
Two refinements to the 'attempt-overwrite-on-read-error' mechanism. 1/ If the array is read-only, don't attempt an over-write. 2/ If there are more than max_nr_stripes read errors on a device with no success, fail the drive. This will make sure a dead drive will be eventually kicked even when we aren't trying to rewrite (which would normally kick a dead drive more quickly. Signed-off-by:
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NeilBrown authored
There isn't really a need for raid5 attributes to be an a subdirectory, so this patch moves them from /sys/block/mdX/md/raid5/attribute to /sys/block/mdX/md/attribute This suggests that all md personalities should co-operate about namespace usage, but that shouldn't be a problem. Signed-off-by:
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NeilBrown authored
Thanks Greg. Cc: Greg KH <greg@kroah.com> Signed-off-by:
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Suzanne Wood authored
Acked-by: <paulmck@us.ibm.com> Signed-off-by:
Suzanne Wood <suzannew@cs.pdx.edu> Signed-off-by:
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NeilBrown authored
With this, raid5 can be asked to check parity without repairing it. It also keeps a count of the number of incorrect parity blocks found (mismatches) and reports them through sysfs. Signed-off-by:
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NeilBrown authored
/sys/block/mdX/md/raid5/ contains raid5-related attributes. Currently stripe_cache_size is number of entries in stripe cache, and is settable. stripe_cache_active is number of active entries, and in only readable. Signed-off-by:
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NeilBrown authored
This patch changes the behaviour of raid5 when it gets a read error. Instead of just failing the device, it tried to find out what should have been there, and writes it over the bad block. For some media-errors, this has a reasonable chance of fixing the error. If the write succeeds, and a subsequent read succeeds as well, raid5 decided the address is OK and conitnues. Instead of failing a drive on read-error, we attempt to re-write the block, and then re-read. If that all works, we allow the device to remain in the array. Signed-off-by:
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- 07 Nov, 2005 1 commit
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Nishanth Aravamudan authored
Use schedule_timeout_interruptible() instead of set_current_state()/schedule_timeout() to reduce kernel size. Signed-off-by:
Nishanth Aravamudan <nacc@us.ibm.com> Cc: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by:
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- 01 Nov, 2005 1 commit
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Jens Axboe authored
Instead of having ->read_sectors and ->write_sectors, combine the two into ->sectors[2] and similar for the other fields. This saves a branch several places in the io path, since we don't have to care for what the actual io direction is. On my x86-64 box, that's 200 bytes less text in just the core (not counting the various drivers). Signed-off-by:Jens Axboe <axboe@suse.de>
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- 09 Sep, 2005 2 commits
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NeilBrown authored
Most awkward part of this is delaying write requests until bitmap updates have been flushed. To achieve this, we have a sequence number (seq_flush) which is incremented each time the raid5 is unplugged. If the raid thread notices that this has changed, it flushes bitmap changes, and assigned the value of seq_flush to seq_write. When a write request arrives, it is given the number from seq_write, and that write request may not complete until seq_flush is larger than the saved seq number. We have a new queue for storing stripes which are waiting for a bitmap flush and an extra flag for stripes to record if the write was 'degraded' and so should not clear the a bit in the bitmap. Signed-off-by:
Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by:
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NeilBrown authored
md does not yet support BIO_RW_BARRIER, so be honest about it and fail (-EOPNOTSUPP) any such requests. Signed-off-by:
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