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path: root/drivers/md/raid5.c
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2005-11-09[PATCH] md: fix some locking and module refcounting issues with md's use of ↵NeilBrown
sysfs 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: Neil Brown <neilb@suse.de> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: make sure a user-request sync of raid5 ignores intent bitmapNeilBrown
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: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: convert 'faulty' and 'in_sync' fields to bits in 'flags' fieldNeilBrown
This has the advantage of removing the confusion caused by 'rdev_t' and 'mddev_t' both having 'in_sync' fields. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: improvements to raid5 handling of read errorsNeilBrown
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: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: change raid5 sysfs attribute to not create a new directoryNeilBrown
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: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: fix ref-counting problems with kobjects in mdNeilBrown
Thanks Greg. Cc: Greg KH <greg@kroah.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: provide proper rcu_dereference / rcu_assign_pointer annotations ↵Suzanne Wood
in md Acked-by: <paulmck@us.ibm.com> Signed-off-by: Suzanne Wood <suzannew@cs.pdx.edu> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: teach raid5 the difference between 'check' and 'repair'.NeilBrown
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: Neil Brown <neilb@suse.de> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: add kobject/sysfs support to raid5NeilBrown
/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: Neil Brown <neilb@suse.de> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] md: better handling of readerrors with raid5.NeilBrown
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: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] drivers/md: fix-up schedule_timeout() usageNishanth Aravamudan
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: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-01[BLOCK] Unify the seperate read/write io stat fields into arraysJens Axboe
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>
2005-09-09[PATCH] md: add write-intent-bitmap support to raid5NeilBrown
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: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: fail IO request to md that require a barrier.NeilBrown
md does not yet support BIO_RW_BARRIER, so be honest about it and fail (-EOPNOTSUPP) any such requests. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-01[PATCH] md: make sure raid5/raid6 resync uses correct 'max_sectors'NeilBrown
The default resync_max_sector is set to "mddev->size << 1". If the raid-personality-module updates mddev->size, it must update resync_max_sectors too. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27[PATCH] md: when resizing an array, we need to update resync_max_sectors as ↵NeilBrown
well as size Without this, and attempt to 'grow' an array will claim to have synced the extra part without actually having done anything. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: fix deadlock due to md thread processing delayed requests.NeilBrown
Before completing a 'write' the md superblock might need to be updated. This is best done by the md_thread. The current code schedules this up and queues the write request for later handling by the md_thread. However some personalities (Raid5/raid6) will deadlock if the md_thread tries to submit requests to its own array. So this patch changes things so the processes submitting the request waits for the superblock to be written and then submits the request itself. This fixes a recently-created deadlock in raid5/raid6 Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: improve the interface to sync_requestNeilBrown
1/ change the return value (which is number-of-sectors synced) from 'int' to 'sector_t'. The number of sectors is usually easily small enough to fit in an int, but if resync needs to abort, it may want to return the total number of remaining sectors, which could be large. Also errors cannot be returned as negative numbers now, so use 0 instead 2/ Add a 'skipped' return parameter to allow the array to report that it skipped the sectors. This allows md to take this into account in the speed calculations. Currently there is no important skipping, but the bitmap-based-resync that is coming will use this. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: improve locking on 'safemode' and move superblock writesNeilBrown
When md marks the superblock dirty before a write, it calls generic_make_request (to write the superblock) from within generic_make_request (to write the first dirty block), which could cause problems later. With this patch, the superblock write is always done by the helper thread, and write request are delayed until that write completes. Also, the locking around marking the array dirty and writing the superblock is improved to avoid possible races. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: merge md_enter_safemode into md_check_recoveryNeilBrown
md_enter_safemode checks if it is time to mark the md superblock as 'clean'. i.e. if all writes have completed and a suitable delay has passed. This is currently called from md_handle_safemode which in-turn is called (almost) every time md_check_recovery is called, and from the end of md_do_sync which causes the mddev->thread to run, which will always call md_check_recovery as well. So it doesn't need to be a separate function and fits quite well into md_check_recovery. The "almost" is because multipathd calls md_check_recovery but not md_handle_safemode. This is OK because the code from md_enter_safemode is a no-op if mddev->safemode == 0, which it always is for a multipathd (providing we don't allow it to be set to 2 on a signal...) Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-17[PATCH] md: set the unplug_fn and issue_flush_fn for md devices *after* ↵NeilBrown
committed to creation We we set the too early, they may still be in place and possibly get called even though the array didn't get set up properly. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01[PATCH] Change synchronize_kernel to _rcu and _schedPaul E. McKenney
This patch changes calls to synchronize_kernel(), deprecated in the earlier "Deprecate synchronize_kernel, GPL replacement" patch to instead call the new synchronize_rcu() and synchronize_sched() APIs. Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!