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path: root/drivers/md/md.h
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2009-04-14md: tiny md.h cleanupsChristoph Hellwig
- update inclusion guard and make sure it covers the whole file - remove superflous #ifdef CONFIG_BLOCK - make sure all required headers are included so that new users aren't required to include others before Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: add explicit method to signal the end of a reshape.NeilBrown
Currently raid5 (the only module that supports restriping) notices that the reshape has finished be sync_request being given a large value, and handles any cleanup them. This patch changes it so md_check_recovery calls into an explicit finish_reshape method as well. The clean-up from sync_request can do things that need to be done promptly, typically things local to the raid5_conf_t structure. The "finish_reshape" method is called under the mddev_lock so it can do things involving reconfiguring the device. This allows us to get rid of md_set_array_sectors_locked, which would have caused a deadlock if you tried to stop and array while a reshape was happening. Signed-off-by: NeilBrown <neilb@suse.de>
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: add ->takeover method to support changing the personality managing an arrayNeilBrown
Implement this for RAID6 to be able to 'takeover' a RAID5 array. The new RAID6 will use a layout which places Q on the last device, and that device will be missing. If there are any available spares, one will immediately have Q recovered onto it. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: enable suspend/resume of md devices.NeilBrown
To be able to change the 'level' of an md/raid array, we need to suspend the device so that no requests are active - then move some pointers around etc. The code already keeps counts of active requests and the ->quiesce function can be used to wait until those counts hit zero. However the quiesce function blocks new requests once they are all ready 'inside' the personality module, and that is too late if we want to replace the personality modules. So make all md requests come in through a common md_make_request function that keeps track of how many requests have entered the modules but may not yet be on the internal reference counts. Allow md_make_request to be blocked when we want to suspend the device, and make it possible to wait for all those in-transit requests to be added to internal lists so that ->quiesce can wait for them. There is still a problem that when a request completes, we drop the ref count inside the personality code so there is a short time between when the refcount hits zero, and when the personality code is no longer being used. The personality code never blocks (schedule or spinlock) between dropping the refcount and exiting the routine, so this should be safe (as put_module calls synchronize_sched() before unmapping the module code). Signed-off-by: NeilBrown <neilb@suse.de>
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: Make mddev->size sector-based.Andre Noll
This patch renames the "size" field of struct mddev_s to "dev_sectors" and stores the number of 512-byte sectors instead of the number of 1K-blocks in it. All users of that field, including raid levels 1,4-6,10, are adjusted accordingly. This simplifies the code a bit because it allows to get rid of a couple of divisions/multiplications by two. In order to make checkpatch happy, some minor coding style issues have also been addressed. In particular, size_store() now uses strict_strtoull() instead of simple_strtoull(). Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: occasionally checkpoint drive recovery to reduce duplicate effort after ↵NeilBrown
a crash Version 1.x metadata has the ability to record the status of a partially completed drive recovery. However we only update that record on a clean shutdown. It would be nice to update it on unclean shutdowns too, particularly when using a bitmap that removes much to the 'sync' effort after an unclean shutdown. One complication with checkpointing recovery is that we only know where we are up to in terms of IO requests started, not which ones have completed. And we need to know what has completed to record how much is recovered. So occasionally pause the recovery until all submitted requests are completed, then update the record of where we are up to. When we have a bitmap, we already do that pause occasionally to keep the bitmap up-to-date. So enhance that code to record the recovery offset and schedule a superblock update. And when there is no bitmap, just pause 16 times during the resync to do a checkpoint. '16' is a fairly arbitrary number. But we don't really have any good way to judge how often is acceptable, and it seems like a reasonable number for now. 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>