kernel/linux.git/drivers/md/raid1.c, branch v2.6.28

md: build failure due to missing delay.h

2008-10-15T10:57:05+00:00

Today's linux-next build (powerpc ppc64_defconfig) failed like this: drivers/md/raid1.c: In function 'sync_request': drivers/md/raid1.c:1759: error: implicit declaration of function 'msleep_interruptible' make[3]: *** [drivers/md/raid1.o] Error 1 make[3]: *** Waiting for unfinished jobs.... drivers/md/raid10.c: In function 'sync_request': drivers/md/raid10.c:1749: error: implicit declaration of function 'msleep_interruptible' make[3]: *** [drivers/md/raid10.o] Error 1 drivers/md/md.c: In function 'md_do_sync': drivers/md/md.c:5915: error: implicit declaration of function 'msleep' Caused by commit 6caa3b0bbdb474647f6bdd8a958ffc46f78d8d58 ("md: Remove unnecessary #includes, #defines, and function declarations"). I added the following patch. Signed-off-by: Stephen Rothwell Signed-off-by: NeilBrown

block: move stats from disk to part0

2008-10-09T06:56:08+00:00

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 Signed-off-by: Jens Axboe

block: fix diskstats access

2008-10-09T06:56:06+00:00

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 Cc: Peter Zijlstra Signed-off-by: Jens Axboe

block: raid fixups for removal of bi_hw_segments

2008-10-09T06:56:03+00:00

Signed-off-by: Jens Axboe

drop vmerge accounting

2008-10-09T06:56:03+00:00

Remove hw_segments field from struct bio and struct request. Without virtual merge accounting they have no purpose. Signed-off-by: Mikulas Patocka Signed-off-by: Jens Axboe

md: Make mddev->array_size sector-based.

2008-07-21T07:05:22+00:00

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 Signed-off-by: NeilBrown

md: resolve external metadata handling deadlock in md_allow_write

2008-07-01T00:18:19+00:00

md_allow_write() marks the metadata dirty while holding mddev->lock and then waits for the write to complete. For externally managed metadata this causes a deadlock as userspace needs to take the lock to communicate that the metadata update has completed. Change md_allow_write() in the 'external' case to start the 'mark active' operation and then return -EAGAIN. The expected side effects while waiting for userspace to write 'active' to 'array_state' are holding off reshape (code currently handles -ENOMEM), cause some 'stripe_cache_size' change requests to fail, cause some GET_BITMAP_FILE ioctl requests to fall back to GFP_NOIO, and cause updates to 'raid_disks' to fail. Except for 'stripe_cache_size' changes these failures can be mitigated by coordinating with mdmon. md_write_start() still prevents writes from occurring until the metadata handler has had a chance to take action as it unconditionally waits for MD_CHANGE_CLEAN to be cleared. [neilb@suse.de: return -EAGAIN, try GFP_NOIO] Signed-off-by: Dan Williams

rationalise return value for ->hot_add_disk method.

2008-06-27T22:31:33+00:00

For all array types but linear, ->hot_add_disk returns 1 on success, 0 on failure. For linear, it returns 0 on success and -errno on failure. This doesn't cause a functional problem because the ->hot_add_disk function of linear is used quite differently to the others. However it is confusing. So convert all to return 0 for success or -errno on failure and fix call sites to match. Signed-off-by: Neil Brown

Support adding a spare to a live md array with external metadata.

2008-06-27T22:31:31+00:00

i.e. extend the 'md/dev-XXX/slot' attribute so that you can tell a device to fill an vacant slot in an and md array. Signed-off-by: Neil Brown

md: restart recovery cleanly after device failure.

2008-05-24T16:56:10+00:00

When we get any IO error during a recovery (rebuilding a spare), we abort the recovery and restart it. For RAID6 (and multi-drive RAID1) it may not be best to restart at the beginning: when multiple failures can be tolerated, the recovery may be able to continue and re-doing all that has already been done doesn't make sense. We already have the infrastructure to record where a recovery is up to and restart from there, but it is not being used properly. This is because: - We sometimes abort with MD_RECOVERY_ERR rather than just MD_RECOVERY_INTR, which causes the recovery not be be checkpointed. - We remove spares and then re-added them which loses important state information. The distinction between MD_RECOVERY_ERR and MD_RECOVERY_INTR really isn't needed. If there is an error, the relevant drive will be marked as Faulty, and that is enough to ensure correct handling of the error. So we first remove MD_RECOVERY_ERR, changing some of the uses of it to MD_RECOVERY_INTR. Then we cause the attempt to remove a non-faulty device from an array to fail (unless recovery is impossible as the array is too degraded). Then when remove_and_add_spares attempts to remove the devices on which recovery can continue, it will fail, they will remain in place, and recovery will continue on them as desired. Issue: If we are halfway through rebuilding a spare and another drive fails, and a new spare is immediately available, do we want to: 1/ complete the current rebuild, then go back and rebuild the new spare or 2/ restart the rebuild from the start and rebuild both devices in parallel. Both options can be argued for. The code currently takes option 2 as a/ this requires least code change b/ this results in a minimally-degraded array in minimal time. Cc: "Eivind Sarto" Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds