linux/drivers/md/raid1.c, branch v3.0

MD: raid1 changes to allow use by device mapper

2011-06-08T05:11:31Z

MD RAID1: Changes to allow RAID1 to be used by device-mapper (dm-raid.c) Added the necessary congestion function and conditionalize calls requiring an array 'queue' or 'gendisk'. Signed-off-by: Jonathan Brassow Signed-off-by: NeilBrown

md: allow resync_start to be set while an array is active.

2011-05-11T05:52:21Z

The sysfs attribute 'resync_start' (known internally as recovery_cp), records where a resync is up to. A value of 0 means the array is not known to be in-sync at all. A value of MaxSector means the array is believed to be fully in-sync. When the size of member devices of an array (RAID1,RAID4/5/6) is increased, the array can be increased to match. This process sets resync_start to the old end-of-device offset so that the new part of the array gets resynced. However with RAID1 (and RAID6) a resync is not technically necessary and may be undesirable. So it would be good if the implied resync after the array is resized could be avoided. So: change 'resync_start' so the value can be changed while the array is active, and as a precaution only allow it to be changed while resync/recovery is 'frozen'. Changing it once resync has started is not going to be useful anyway. This allows the array to be resized without a resync by: write 'frozen' to 'sync_action' write new size to 'component_size' (this will set resync_start) write 'none' to 'resync_start' write 'idle' to 'sync_action'. Also slightly improve some tests on recovery_cp when resizing raid1/raid5. Now that an arbitrary value could be set we should be more careful in our tests. Signed-off-by: NeilBrown

md/raid1: improve handling of pages allocated for write-behind.

2011-05-11T04:51:19Z

The current handling and freeing of these pages is a bit fragile. We only keep the list of allocated pages in each bio, so we need to still have a valid bio when freeing the pages, which is a bit clumsy. So simply store the allocated page list in the r1_bio so it can easily be found and freed when we are finished with the r1_bio. Signed-off-by: NeilBrown

md/raid1: try fix_sync_read_error before process_checks.

2011-05-11T04:50:37Z

If we get a read error during resync/recovery we current repeat with single-page reads to find out just where the error is, and possibly read each page from a different device. With check/repair we don't currently do that, we just fail. However it is possible that while all devices fail on the large 64K read, we might be able to satisfy each 4K from one device or another. So call fix_sync_read_error before process_checks to maximise the chance of finding good data and writing it out to the devices with read errors. For this to work, we need to set the 'uptodate' flags properly after fix_sync_read_error has succeeded. Signed-off-by: NeilBrown

md/raid1: tidy up new functions: process_checks and fix_sync_read_error.

2011-05-11T04:48:56Z

These changes are mostly cosmetic: 1/ change mddev->raid_disks to conf->raid_disks because the later is technically safer, though in current practice it doesn't matter in this particular context. 2/ Rearrange two for / if loops to have an early 'continue' so the body of the 'if' doesn't need to be indented so much. Signed-off-by: NeilBrown

md/raid1: split out two sub-functions from sync_request_write

2011-05-11T04:40:44Z

sync_request_write is too big and too deep. So split out two self-contains bits of functionality into separate function. Signed-off-by: NeilBrown

md/raid1: clean up read_balance.

2011-05-11T04:34:56Z

read_balance has two loops which both look for a 'best' device based on slightly different criteria. This is clumsy and makes is hard to add extra criteria. So replace it all with a single loop that combines everything. Signed-off-by: NeilBrown

md: fix up raid1/raid10 unplugging.

2011-04-18T08:25:43Z

We just need to make sure that an unplug event wakes up the md thread, which is exactly what mddev_check_plugged does. Also remove some plug-related code that is no longer needed. Signed-off-by: NeilBrown

md: use new plugging interface for RAID IO.

2011-04-18T08:25:41Z

md/raid submits a lot of IO from the various raid threads. So adding start/finish plug calls to those so that some plugging happens. Signed-off-by: NeilBrown

block: Require subsystems to explicitly allocate bio_set integrity mempool

2011-03-17T10:11:05Z

MD and DM create a new bio_set for every metadevice. Each bio_set has an integrity mempool attached regardless of whether the metadevice is capable of passing integrity metadata. This is a waste of memory. Instead we defer the allocation decision to MD and DM since we know at metadevice creation time whether integrity passthrough is needed or not. Automatic integrity mempool allocation can then be removed from bioset_create() and we make an explicit integrity allocation for the fs_bio_set. Signed-off-by: Martin K. Petersen Reported-by: Zdenek Kabelac Acked-by: Mike Snitzer Signed-off-by: Jens Axboe