md-cluster: Improve md_reload_sb to be less error prone
md_reload_sb is too simplistic and it explicitly needs to determine
the changes made by the writing node. However, there are multiple areas
where a simple reload could fail.
Instead, read the superblock of one of the "good" rdevs and update
the necessary information:
- read the superblock into a newly allocated page, by temporarily
swapping out rdev->sb_page and calling ->load_super.
- if that fails return
- if it succeeds, call check_sb_changes
1. iterates over list of active devices and checks the matching
dev_roles[] value.
If that is 'faulty', the device must be marked as faulty
- call md_error to mark the device as faulty. Make sure
not to set CHANGE_DEVS and wakeup mddev->thread or else
it would initiate a resync process, which is the responsibility
of the "primary" node.
- clear the Blocked bit
- Call remove_and_add_spares() to hot remove the device.
If the device is 'spare':
- call remove_and_add_spares() to get the number of spares
added in this operation.
- Reduce mddev->degraded to mark the array as not degraded.
2. reset recovery_cp
- read the rest of the rdevs to update recovery_offset. If recovery_offset
is equal to MaxSector, call spare_active() to set it In_sync
This required that recovery_offset be initialized to MaxSector, as
opposed to zero so as to communicate the end of sync for a rdev.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
4 files changed