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* md: linear: Fix a division by zero bug for very small arrays.Andre Noll2008-11-061-0/+2
| | | | | | | | | | | | | | | | | | We currently oops with a divide error on starting a linear software raid array consisting of at least two very small (< 500K) devices. The bug is caused by the calculation of the hash table size which tries to compute sector_div(sz, base) with "base" being zero due to the small size of the component devices of the array. Fix this by requiring the hash spacing to be at least one which implies that also "base" is non-zero. This bug has existed since about 2.6.14. Cc: stable@kernel.org Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
* md: Remove unnecessary #includes, #defines, and function declarations.NeilBrown2008-10-131-8/+0Star
| | | | | | A lot of cruft has gathered over the years. Time to remove it. Signed-off-by: NeilBrown <neilb@suse.de>
* md: Convert remaining 1k representations in linear.c to sectors.Andre Noll2008-10-131-18/+17Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch renames hash_spacing and preshift to spacing and sector_shift respectively with the following change of semantics: Case 1: (sizeof(sector_t) <= sizeof(u32)). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In this case, we have sector_shift = preshift = 0 and spacing = 2 * hash_spacing. Hence, the index for the hash table which is computed by the new code in which_dev() as sector / spacing equals the old value which was (sector/2) / hash_spacing. Note also that the value of nb_zone stays the same because both sz and base double. Case 2: (sizeof(sector_t) > sizeof(u32)). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (aka the shifting dance case). Here we have sector_shift = preshift + 1 and spacing = 2 * hash_spacing during the computation of nb_zone and curr_sector, but spacing = hash_spacing in which_dev() because in the last hunk of the patch for linear.c we shift down conf->spacing (= 2 * hash_spacing) by one more bit than in the old code. Hence in the computation of nb_zone, sz and base have the same value as before, so nb_zone is not affected. Also curr_sector in the next hunk stays the same. In which_dev() the hash table index is computed as (sector >> sector_shift) / spacing In view of sector_shift = preshift + 1 and spacing = hash_spacing, this equals ((sector/2) >> preshift) / hash_spacing which is the value computed by the old code. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
* md: linear.c: Make two local variables sector-based.Andre Noll2008-10-131-10/+10
| | | | | | | | This is a preparation for representing also the remaining fields of struct linear_private_data as sectors. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
* md: linear: Represent dev_info->size and dev_info->offset in sectors.Andre Noll2008-10-131-25/+29
| | | | | | | Rename them to num_sectors and start_sector which is more descriptive. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
* md: linear.c: Remove broken debug code.Andre Noll2008-10-131-23/+0Star
| | | | | | | conf->smallest_size is undefined since day one of the git repo.. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
* md: linear.c: Remove pointless initialization of curr_offset.Andre Noll2008-10-131-1/+0Star
| | | | | Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
* md: linear.c: Fix typo in comment.Andre Noll2008-10-131-1/+1
| | | | | Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
* block: mark bio_split_pool staticDenis ChengRq2008-10-091-1/+1
| | | | | | | | | | | Since all bio_split calls refer the same single bio_split_pool, the bio_split function can use bio_split_pool directly instead of the mempool_t parameter; then the mempool_t parameter can be removed from bio_split param list, and bio_split_pool is only referred in fs/bio.c file, can be marked static. Signed-off-by: Denis ChengRq <crquan@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move stats from disk to part0Tejun Heo2008-10-091-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move stats related fields - stamp, in_flight, dkstats - from disk to part0 and unify stat handling such that... * part_stat_*() now updates part0 together if the specified partition is not part0. ie. part_stat_*() are now essentially all_stat_*(). * {disk|all}_stat_*() are gone. * part_round_stats() is updated similary. It handles part0 stats automatically and disk_round_stats() is killed. * part_{inc|dec}_in_fligh() is implemented which automatically updates part0 stats for parts other than part0. * disk_map_sector_rcu() is updated to return part0 if no part matches. Combined with the above changes, this makes NULL special case handling in callers unnecessary. * Separate stats show code paths for disk are collapsed into part stats show code paths. * Rename disk_stat_lock/unlock() to part_stat_lock/unlock() While at it, reposition stat handling macros a bit and add missing parentheses around macro parameters. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix diskstats accessTejun Heo2008-10-091-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two variants of stat functions - ones prefixed with double underbars which don't care about preemption and ones without which disable preemption before manipulating per-cpu counters. It's unclear whether the underbarred ones assume that preemtion is disabled on entry as some callers don't do that. This patch unifies diskstats access by implementing disk_stat_lock() and disk_stat_unlock() which take care of both RCU (for partition access) and preemption (for per-cpu counter access). diskstats access should always be enclosed between the two functions. As such, there's no need for the versions which disables preemption. They're removed and double underbars ones are renamed to drop the underbars. As an extra argument is added, there's no danger of using the old version unconverted. disk_stat_lock() uses get_cpu() and returns the cpu index and all diskstat functions which access per-cpu counters now has @cpu argument to help RT. This change adds RCU or preemption operations at some places but also collapses several preemption ops into one at others. Overall, the performance difference should be negligible as all involved ops are very lightweight per-cpu ones. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds2008-07-211-10/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://neil.brown.name/md: (52 commits) md: Protect access to mddev->disks list using RCU md: only count actual openers as access which prevent a 'stop' md: linear: Make array_size sector-based and rename it to array_sectors. md: Make mddev->array_size sector-based. md: Make super_type->rdev_size_change() take sector-based sizes. md: Fix check for overlapping devices. md: Tidy up rdev_size_store a bit: md: Remove some unused macros. md: Turn rdev->sb_offset into a sector-based quantity. md: Make calc_dev_sboffset() return a sector count. md: Replace calc_dev_size() by calc_num_sectors(). md: Make update_size() take the number of sectors. md: Better control of when do_md_stop is allowed to stop the array. md: get_disk_info(): Don't convert between signed and unsigned and back. md: Simplify restart_array(). md: alloc_disk_sb(): Return proper error value. md: Simplify sb_equal(). md: Simplify uuid_equal(). md: sb_equal(): Fix misleading printk. md: Fix a typo in the comment to cmd_match(). ...
| * md: linear: Make array_size sector-based and rename it to array_sectors.Andre Noll2008-07-211-8/+8
| | | | | | | | | | Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
| * md: Make mddev->array_size sector-based.Andre Noll2008-07-211-3/+3
| | | | | | | | | | | | | | | | | | This patch renames the array_size field of struct mddev_s to array_sectors and converts all instances to use units of 512 byte sectors instead of 1k blocks. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
| * linear: correct disk numbering error checkNikanth Karthikesan2008-06-281-1/+1
| | | | | | | | | | | | | | | | | | From: "Nikanth Karthikesan" <knikanth@novell.com> Correct disk numbering problem check. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Neil Brown <neilb@suse.de>
* | Add bvec_merge_data to handle stacked devices and ->merge_bvec()Alasdair G Kergon2008-07-031-4/+6
|/ | | | | | | | | | | | | | | | | | | | | | When devices are stacked, one device's merge_bvec_fn may need to perform the mapping and then call one or more functions for its underlying devices. The following bio fields are used: bio->bi_sector bio->bi_bdev bio->bi_size bio->bi_rw using bio_data_dir() This patch creates a new struct bvec_merge_data holding a copy of those fields to avoid having to change them directly in the struct bio when going down the stack only to have to change them back again on the way back up. (And then when the bio gets mapped for real, the whole exercise gets repeated, but that's a problem for another day...) Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: Milan Broz <mbroz@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Remove blkdev warning triggered by using mdNeil Brown2008-05-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | As setting and clearing queue flags now requires that we hold a spinlock on the queue, and as blk_queue_stack_limits is called without that lock, get the lock inside blk_queue_stack_limits. For blk_queue_stack_limits to be able to find the right lock, each md personality needs to set q->queue_lock to point to the appropriate lock. Those personalities which didn't previously use a spin_lock, us q->__queue_lock. So always initialise that lock when allocated. With this in place, setting/clearing of the QUEUE_FLAG_PLUGGED bit will no longer cause warnings as it will be clear that the proper lock is held. Thanks to Dan Williams for review and fixing the silly bugs. Signed-off-by: NeilBrown <neilb@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Alistair John Strachan <alistair@devzero.co.uk> Cc: Nick Piggin <npiggin@suse.de> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Jacek Luczak <difrost.kernel@gmail.com> Cc: Prakash Punnoor <prakash@punnoor.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: change ITERATE_RDEV to rdev_for_eachNeilBrown2008-02-061-1/+1
| | | | | | | | | As this is more in line with common practice in the kernel. Also swap the args around to be more like list_for_each. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add UNPLUG traces to all appropriate placesAlan D. Brunelle2007-11-091-2/+1Star
| | | | | | | | Added blk_unplug interface, allowing all invocations of unplugs to result in a generated blktrace UNPLUG. Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: convert blkdev_issue_flush() to use empty barriersJens Axboe2007-10-161-20/+0Star
| | | | | | | Then we can get rid of ->issue_flush_fn() and all the driver private implementations of that. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Drop 'size' argument from bio_endio and bi_end_ioNeilBrown2007-10-101-2/+2
| | | | | | | | | | | | | As bi_end_io is only called once when the reqeust is complete, the 'size' argument is now redundant. Remove it. Now there is no need for bio_endio to subtract the size completed from bi_size. So don't do that either. While we are at it, change bi_end_io to return void. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* [BLOCK] Get rid of request_queue_t typedefJens Axboe2007-07-241-7/+7
| | | | | | | | | Some of the code has been gradually transitioned to using the proper struct request_queue, but there's lots left. So do a full sweet of the kernel and get rid of this typedef and replace its uses with the proper type. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* md: fix bug with linear hot-add and elsewhereNeilBrown2007-05-241-5/+5
| | | | | | | | | | | | | | Adding a drive to a linear array seems to have stopped working, due to changes elsewhere in md, and insufficient ongoing testing... So the patch to make linear hot-add work in the first place introduced a subtle bug elsewhere that interracts poorly with older version of mdadm. This fixes it all up. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] fix read past end of array in md/linear.cAndy Isaacson2007-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When iterating through an array, one must be careful to test one's index variable rather than another similarly-named variable. The loop will read off the end of conf->disks[] in the following (pathological) case: % dd bs=1 seek=840716287 if=/dev/zero of=d1 count=1 % for i in 2 3 4; do dd if=/dev/zero of=d$i bs=1k count=$(($i+150)); done % ./vmlinux ubd0=root ubd1=d1 ubd2=d2 ubd3=d3 ubd4=d4 # mdadm -C /dev/md0 --level=linear --raid-devices=4 /dev/ubd[1234] adding some printks, I saw this: [42949374.960000] hash_spacing = 821120 [42949374.960000] cnt = 4 [42949374.960000] min_spacing = 801 [42949374.960000] j=0 size=820928 sz=820928 [42949374.960000] i=0 sz=820928 hash_spacing=820928 [42949374.960000] j=1 size=64 sz=64 [42949374.960000] j=2 size=64 sz=128 [42949374.960000] j=3 size=64 sz=192 [42949374.960000] j=4 size=1515870810 sz=1515871002 Cc: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Neil Brown <neilb@cse.unsw.edu.au> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] md: define backing_dev_info.congested_fn for raid0 and linearNeilBrown2006-10-031-0/+15
| | | | | | | | | | | Each backing_dev needs to be able to report whether it is congested, either by modulating BDI_*_congested in ->state, or by defining a ->congested_fn. md/raid did neither of these. This patch add a congested_fn which simply checks all component devices to see if they are congested. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: Fix a bug that recently crept into md/linearNeilBrown2006-08-061-3/+3
| | | | | | | | | | | | | | | | | A recent patch that allowed linear arrays to be reconfigured on-line allowed in a bug which results in divide by zero - not all mddev->array_size were converted to conf->array_size. This patch finished the conversion and fixed the bug. The offending patch was commit 7c7546ccf6463edbeee8d9aac6de7be1cd80d08a. Thanks to Simon Kirby <sim@netnation.com> for the bug report. Cc: Simon Kirby <sim@netnation.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>
* [PATCH] md: allow a linear array to have drives added while activeNeilBrown2006-06-261-13/+61
| | | | | | Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: allow array level to be set textually via sysfsNeilBrown2006-01-061-1/+2
| | | | | | | Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: remove personality numbering from mdNeilBrown2006-01-061-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: convert md to use kzalloc throughoutNeilBrown2006-01-061-2/+1Star
| | | | | | | | Replace multiple kmalloc/memset pairs with kzalloc calls. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [BLOCK] Unify the seperate read/write io stat fields into arraysJens Axboe2005-11-011-7/+3Star
| | | | | | | | | | 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>
* [PATCH] md: support md/linear array with components greater than 2 terabytes.NeilBrown2005-09-101-29/+66
| | | | | | | | | | | | | | | linear currently uses division by the size of the smallest componenet device to find which device a request goes to. If that smallest device is larger than 2 terabytes, then the division will not work on some systems. So we introduce a pre-shift, and take care not to make the hash table too large, much like the code in raid0. Also get rid of conf->nr_zones, which is not needed. 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>
* [PATCH] md: fail IO request to md that require a barrier.NeilBrown2005-09-101-0/+5
| | | | | | | | | 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>
* [PATCH] md: remove unneeded NULL checks before kfreeJesper Juhl2005-06-221-2/+1Star
| | | | | | | | | | This patch removes some unneeded checks of pointers being NULL before calling kfree() on them. kfree() handles NULL pointers just fine, checking first is pointless. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: fix splitting of md/linear request that cross a device boundaryNeilBrown2005-05-171-3/+2Star
| | | | | | | | | | | When a request crosses a boundary between devices, it needs to be split. But where we should calculate the amount of the request before the boundary to find the split-point, we care currently calculating the amount that is *after* the boundary !!! 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>
* Linux-2.6.12-rc2Linus Torvalds2005-04-171-0/+343
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!
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