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path: root/drivers/md/raid0.c
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2009-06-18md: Move check for bitmap presence to personality code.Andre Noll
If the superblock of a component device indicates the presence of a bitmap but the corresponding raid personality does not support bitmaps (raid0, linear, multipath, faulty), then something is seriously wrong and we'd better refuse to run such an array. Currently, this check is performed while the superblocks are examined, i.e. before entering personality code. Therefore the generic md layer must know which raid levels support bitmaps and which do not. This patch avoids this layer violation without adding identical code to various personalities. This is accomplished by introducing a new public function to md.c, md_check_no_bitmap(), which replaces the hard-coded checks in the superblock loading functions. A call to md_check_no_bitmap() is added to the ->run method of each personality which does not support bitmaps and assembly is aborted if at least one component device contains a bitmap. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: raid0/linear: ensure device sizes are rounded to chunk size.NeilBrown
This is currently ensured by common code, but it is more reliable to ensure it where it is needed in personality code. All the other personalities that care already round the size to the chunk_size. raid0 and linear are the only hold-outs. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: raid0: chunk_sectors cleanups.NeilBrown
following the conversion to chunk_sectors, there is room for cleaning up a little. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: Make mddev->chunk_size sector-based.Andre Noll
This patch renames the chunk_size field to chunk_sectors with the implied change of semantics. Since is_power_of_2(chunk_size) = is_power_of_2(chunk_sectors << 9) = is_power_of_2(chunk_sectors) these bits don't need an adjustment for the shift. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0 :Enables chunk size other than powers of 2.raz ben yehuda
Maintain two flows, one for pow2 chunk sizes (which uses masks and shift), and a flow for the general case (which uses sector_div). This is for the sake of performance. - introduce map_sector and is_io_in_chunk_boundary to encapsulate those two flows better for raid0_make_request - fix blk_mergeable to support the two flows. Signed-off-by: raziebe@gmail.com Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: chunk size check in raid0_runraz ben yehuda
have raid0 check chunk size in run method instead of in md. This is part of a series moving the checks from common code to the personalities where they belong. hardsect is short and chunksize is an int, so it is safe to use %. Signed-off-by: raziebe@gmail.com Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: have raid0 report its formationraz ben yehuda
Report to the user what are the raid zones Signed-off-by: raziebe@gmail.com Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: have raid0 compile with MD_DEBUG onraz ben yehuda
Because of the removal of the device list from the strips raid0 did not compile with MD_DEBUG flag on Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: remove mddev_to_conf "helper" macroNeilBrown
Having a macro just to cast a void* isn't really helpful. I would must rather see that we are simply de-referencing ->private, than have to know what the macro does. So open code the macro everywhere and remove the pointless cast. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: remove setting of segment boundary.NeilBrown
This setting doesn't seem to make sense (half the chunk size??) and shouldn't be needed. The segment boundary exported by raid0 should simply be the minimum of the segment boundary of all component devices. And we already get that right. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: remove ->dev pointer from strip_zone structureNeilBrown
If we treat conf->devlist more like a 2 dimensional array, we can get the devlist for a particular zone simply by indexing that array, so we don't need to store the pointers to subarrays in strip_zone. This makes strip_zone smaller and so (hopefully) searches faster. Signed-of-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: remove ->sectors from the strip_zone structure.NeilBrown
storing ->sectors is redundant as is can be computed from the difference z->zone_end - (z-1)->zone_end The one place where it is used, it is just as efficient to use a zone_end value instead. And removing it makes strip_zone smaller, so they array of these that is searched on every request has a better chance to say in cache. So discard the field and get the value from elsewhere. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: Fix a memory leak when stopping a raid0 array.Andre Noll
raid0_stop() removes all references to the raid0 configuration but misses to free the ->devlist buffer. This patch closes this leak, removes a pointless initialization and fixes a coding style issue in raid0_stop(). Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: Allocate all buffers for the raid0 configuration in one function.Andre Noll
Currently the raid0 configuration is allocated in raid0_run() while the buffers for the strip_zone and the dev_list arrays are allocated in create_strip_zones(). On errors, all three buffers are freed in raid0_run(). It's easier and more readable to do the allocation and cleanup within a single function. So move that code into create_strip_zones(). Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: Make raid0_run() return a proper error code.Andre Noll
Currently raid0_run() always returns -ENOMEM on errors. This is incorrect as running the array might fail for other reasons, for example because not all component devices were available. This patch changes create_strip_zones() so that it returns a proper error code (either -ENOMEM or -EINVAL) rather than 1 on errors and makes raid0_run(), its single caller, return that value instead of -ENOMEM. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: Remove hash spacing and sector shift.Andre Noll
The "sector_shift" and "spacing" fields of struct raid0_private_data were only used for the hash table lookups. So the removal of the hash table allows get rid of these fields as well which simplifies create_strip_zones() and raid0_run() quite a bit. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: Remove hash table.Andre Noll
The raid0 hash table has become unused due to the changes in the previous patch. This patch removes the hash table allocation and setup code and kills the hash_table field of struct raid0_private_data. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md/raid0: two cleanups in create_stripe_zones.NeilBrown
1/ remove current_start. The same value is available in zone->dev_start and storing it separately doesn't gain anything. 2/ rename curr_zone_start to curr_zone_end as we are now more focused on the 'end' of each zone. We end up storing the same number though - the old name was a little confusing (and what does 'current' mean in this context anyway). Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: raid0: Replace hash table lookup by looping over all strip_zones.Andre Noll
The number of strip_zones of a raid0 array is bounded by the number of drives in the array and is in fact much smaller for typical setups. For example, any raid0 array containing identical disks will have only a single strip_zone. Therefore, the hash tables which are used for quickly finding the strip_zone that holds a particular sector are of questionable value and add quite a bit of unnecessary complexity. This patch replaces the hash table lookup by equivalent code which simply loops over all strip zones to find the zone that holds the given sector. In order to make this loop as fast as possible, the zone->start field of struct strip_zone has been renamed to zone_end, and it now stores the beginning of the next zone in sectors. This allows to save one addition in the loop. Subsequent cleanup patches will remove the hash table structure. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-22block: Use accessor functions for queue limitsMartin K. Petersen
Convert all external users of queue limits to using wrapper functions instead of poking the request queue variables directly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-31md: 'array_size' sysfs attributeDan Williams
Allow userspace to set the size of the array according to the following semantics: 1/ size must be <= to the size returned by mddev->pers->size(mddev, 0, 0) a) If size is set before the array is running, do_md_run will fail if size is greater than the default size b) A reshape attempt that reduces the default size to less than the set array size should be blocked 2/ once userspace sets the size the kernel will not change it 3/ writing 'default' to this attribute returns control of the size to the kernel and reverts to the size reported by the personality Also, convert locations that need to know the default size from directly reading ->array_sectors to <pers>_size. Resync/reshape operations always follow the default size. Finally, fixup other locations that read a number of 1k-blocks from userspace to use strict_blocks_to_sectors() which checks for unsigned long long to sector_t overflow and blocks to sectors overflow. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md: centralize ->array_sectors modificationsDan Williams
Get personalities out of the business of directly modifying ->array_sectors. Lays groundwork to introduce policy on when ->array_sectors can be modified. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md: add 'size' as a personality methodDan Williams
In preparation for giving userspace control over ->array_sectors we need to be able to retrieve the 'default' size, and the 'anticipated' size when a reshape is requested. For personalities that do not reshape emit a warning if anything but the default size is requested. In the raid5 case we need to update ->previous_raid_disks to make the new 'default' size available. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md: Represent raid device size in sectors.Andre Noll
This patch renames the "size" field of struct mdk_rdev_s to "sectors" and changes this field to store sectors instead of blocks. All users of this field, linear.c, raid0.c and md.c, are fixed up accordingly which gets rid of many multiplications and divisions. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move md_k.h from include/linux/raid/ to drivers/md/NeilBrown
It really is nicer to keep related code together.. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move lots of #include lines out of .h files and into .cNeilBrown
This makes the includes more explicit, and is preparation for moving md_k.h to drivers/md/md.h Remove include/raid/md.h as its only remaining use was to #include other files. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move headers out of include/linux/raid/Christoph Hellwig
Move the headers with the local structures for the disciplines and bitmap.h into drivers/md/ so that they are more easily grepable for hacking and not far away. md.h is left where it is for now as there are some uses from the outside. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: use list_for_each_entry macro directlyCheng Renquan
The rdev_for_each macro defined in <linux/raid/md_k.h> is identical to list_for_each_entry_safe, from <linux/list.h>, it should be defined to use list_for_each_entry_safe, instead of reinventing the wheel. But some calls to each_entry_safe don't really need a safe version, just a direct list_for_each_entry is enough, this could save a temp variable (tmp) in every function that used rdev_for_each. In this patch, most rdev_for_each loops are replaced by list_for_each_entry, totally save many tmp vars; and only in the other situations that will call list_del to delete an entry, the safe version is used. Signed-off-by: Cheng Renquan <crquan@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0: make hash_spacing and preshift sector-based.Andre Noll
This patch renames the hash_spacing and preshift members of struct raid0_private_data to spacing and sector_shift respectively and changes the semantics as follows: We always have spacing = 2 * hash_spacing. In case sizeof(sector_t) > sizeof(u32) we also have sector_shift = preshift + 1 while sector_shift = preshift = 0 otherwise. Note that the values of nb_zone and zone are unaffected by these changes because in the sector_div() preceeding the assignement of these two variables both arguments double. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0: Represent the size of strip zones in sectors.Andre Noll
This completes the block -> sector conversion of struct strip_zone. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0 create_strip_zones(): Add KERN_INFO/KERN_ERR to printk's.Andre Noll
This patch consists only of these trivial changes. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0 create_strip_zones(): Make two local variables sector-based.Andre Noll
current_offset and curr_zone_offset stored the corresponding offsets as 1K quantities. Rename them to current_start and curr_zone_start to match the naming of struct strip_zone and store the offsets as sector counts. Also, add KERN_INFO to the printk() affected by this change to make checkpatch happy. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0: Represent zone->zone_offset in sectors.Andre Noll
For the same reason as in the previous patch, rename it from zone_offset to zone_start. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0: Represent device offset in sectors.Andre Noll
Rename zone->dev_offset to zone->dev_start to make sure all users have been converted. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0_make_request(): Replace local variable block by sector.Andre Noll
This change already simplifies the code a bit. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0_make_request(): Remove local variable chunk_size.Andre Noll
We might as well use chunk_sects instead. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09md: raid0_make_request(): Replace chunksize_bits by chunksect_bits.Andre Noll
As ffz(~(2 * x)) = ffz(~x) + 1, we have chunksect_bits = chunksize_bits + 1. Fixup all users accordingly. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-13md: Remove unnecessary #includes, #defines, and function declarations.NeilBrown
A lot of cruft has gathered over the years. Time to remove it. Signed-off-by: NeilBrown <neilb@suse.de>
2008-10-09block: mark bio_split_pool staticDenis ChengRq
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>
2008-10-09block: move stats from disk to part0Tejun Heo
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>
2008-10-09block: fix diskstats accessTejun Heo
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>
2008-07-21Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds
* '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(). ...
2008-07-21md: Make mddev->array_size sector-based.Andre Noll
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>
2008-07-03Add bvec_merge_data to handle stacked devices and ->merge_bvec()Alasdair G Kergon
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>
2008-05-14Remove blkdev warning triggered by using mdNeil Brown
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>
2008-02-06md: change ITERATE_RDEV to rdev_for_eachNeilBrown
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>
2007-11-09Add UNPLUG traces to all appropriate placesAlan D. Brunelle
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>
2007-10-17md: fix a bug in some never-used code.NeilBrown
http://bugzilla.kernel.org/show_bug.cgi?id=3277 There is a seq_printf here that isn't being passed a 'seq'. Howeve as the code is inside #ifdef MD_DEBUG, nobody noticed. Also remove some extra spaces. 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>
2007-10-16block: convert blkdev_issue_flush() to use empty barriersJens Axboe
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>
2007-10-10Drop 'size' argument from bio_endio and bi_end_ioNeilBrown
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>