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| author | NeilBrown <neilb@suse.de> | 2012-05-21 09:27:00 +1000 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2012-05-21 09:27:00 +1000 |
| commit | c6563a8c38fde3c1c7fc925a10bde3ca20799301 (patch) | |
| tree | 3916ae8247149a9dcf39ee1ca262f97be39071eb /include/linux/raid | |
| parent | 2c810cddc44d6f95cef75df3f07fc0850ff92417 (diff) | |
| download | linux-c6563a8c38fde3c1c7fc925a10bde3ca20799301.tar.gz linux-c6563a8c38fde3c1c7fc925a10bde3ca20799301.tar.bz2 linux-c6563a8c38fde3c1c7fc925a10bde3ca20799301.zip | |
md: add possibility to change data-offset for devices.
When reshaping we can avoid costly intermediate backup by
changing the 'start' address of the array on the device
(if there is enough room).
So as a first step, allow such a change to be requested
through sysfs, and recorded in v1.x metadata.
(As we didn't previous check that all 'pad' fields were zero,
we need a new FEATURE flag for this.
A (belatedly) check that all remaining 'pad' fields are
zero to avoid a repeat of this)
The new data offset must be requested separately for each device.
This allows each to have a different change in the data offset.
This is not likely to be used often but as data_offset can be
set per-device, new_data_offset should be too.
This patch also removes the 'acknowledged' arg to rdev_set_badblocks as
it is never used and never will be. At the same time we add a new
arg ('in_new') which is currently always zero but will be used more
soon.
When a reshape finishes we will need to update the data_offset
and rdev->sectors. So provide an exported function to do that.
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'include/linux/raid')
| -rw-r--r-- | include/linux/raid/md_p.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h index 07e05f92d050..ee753536ab70 100644 --- a/include/linux/raid/md_p.h +++ b/include/linux/raid/md_p.h @@ -233,7 +233,10 @@ struct mdp_superblock_1 { __le32 delta_disks; /* change in number of raid_disks */ __le32 new_layout; /* new layout */ __le32 new_chunk; /* new chunk size (512byte sectors) */ - __u8 pad1[128-124]; /* set to 0 when written */ + __le32 new_offset; /* signed number to add to data_offset in new + * layout. 0 == no-change. This can be + * different on each device in the array. + */ /* constant this-device information - 64 bytes */ __le64 data_offset; /* sector start of data, often 0 */ @@ -285,11 +288,14 @@ struct mdp_superblock_1 { * of devices, but is going * backwards anyway. */ +#define MD_FEATURE_NEW_OFFSET 64 /* new_offset must be honoured */ #define MD_FEATURE_ALL (MD_FEATURE_BITMAP_OFFSET \ |MD_FEATURE_RECOVERY_OFFSET \ |MD_FEATURE_RESHAPE_ACTIVE \ |MD_FEATURE_BAD_BLOCKS \ |MD_FEATURE_REPLACEMENT \ - |MD_FEATURE_RESHAPE_BACKWARDS) + |MD_FEATURE_RESHAPE_BACKWARDS \ + |MD_FEATURE_NEW_OFFSET \ + ) #endif |