md-cluster: A better way for METADATA_UPDATED processing
The processing of METADATA_UPDATED message is too simple and prone to
errors. Besides, it would not update the internal data structures as
required.
This set of patches reads the superblock from one of the device of the MD
and checks for changes in the in-memory data structures. If there is a change,
it performs the necessary actions to keep the internal data structures
as it would be in the primary node.
An example is if a devices turns faulty. The algorithm is:
1. The initiator node marks the device as faulty and updates the superblock
2. The initiator node sends METADATA_UPDATED with an advisory device number to the rest of the nodes.
3. The receiving node on receiving the METADATA_UPDATED message
3.1 Reads the superblock
3.2 Detects a device has failed by comparing with memory structure
3.3 Calls the necessary functions to record the failure and get the device out of the active array.
3.4 Acknowledges the message.
The patch series also fixes adding the disk which was impacted because of
the changes.
Patches can also be found at
https://github.com/goldwynr/linux branch md-next
Changes since V2:
- Fix status synchrnoization after --add and --re-add operations
- Included Guoqing's patches on endian correctness, zeroing cmsg etc
- Restructure add_new_disk() and cancel()
For cluster raid, we should not kick it from array if the disk can't be
remove from array successfully.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
During the past test, the node occasionally received the msg which is
sent from itself, this case should not happen in theory, but it is
better to avoid it in case something wrong happened.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
The receive daemon prints kernel messages for every network message
received. This would fill the kernel message log with unnecessary messages.
Remove the pr_info() messages.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Adding the disk worked incorrectly with the new reload code. Fix it:
- No operation should be performed on rdev marked as Candidate
- After a metadata update operation, kick disk if role is 0xfffe
else clear Candidate bit and continue with the regular change check.
- Saving the mode of the lock resource to check if token lock is already
locked, because it can be called twice while adding a disk. However,
unlock_comm() must be called only once.
- add_new_disk() is called by the node initiating the --add operation.
If it needs to be canceled, call add_new_disk_cancel(). The operation
is completed by md_update_sb() which will write and unlock the
communication.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Resync or recovery must be performed by only one node at a time.
A DLM lock resource, resync_lockres provides the mutual exclusion
so that only one node performs the recovery/resync at a time.
If a node is unable to get the resync_lockres, because recovery is
being performed by another node, it set MD_RECOVER_NEEDED so as
to schedule recovery in the future.
Remove the debug message in resync_info_update()
used during development.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
In a clustered environment, a change such as marking a device faulty,
can be recorded by any of the nodes. This is communicated to all the
nodes and re-recording such a change is unnecessary, and quite often
pretty disruptive.
With this patch, just before the update, we detect for the changes
and if the changes are already in superblock, we abort the update
after clearing all the flags
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
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>
remove_and_add_spares() checks for all devices to activate spare.
Change it to activate a specific device if a non-null rdev
argument is passed.
remove_and_add_spares() can be used to activate spares in
slot_store() as well.
For hot_remove_disk(), check if rdev->raid_disk == -1 before
calling remove_and_add_spares()
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
When the suspended_area is deleted, the suspended processes
must be woken up in order to complete their I/O.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Previously, BITMAP_NEEDS_SYNC message is sent when the resyc
aborts, but it could abort for different reasons, and not all
of reasons require another node to take over the resync ownship.
It is better make BITMAP_NEEDS_SYNC message only be sent when
the node is leaving cluster with dirty bitmap. And we also need
to ensure dlm connection is ok.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Suspending the entire device for resync could take too long. Resync
in small chunks.
cluster's resync window (32M) is maintained in r1conf as
cluster_sync_low and cluster_sync_high and processed in
raid1's sync_request(). If the current resync is outside the cluster
resync window:
1. Set the cluster_sync_low to curr_resync_completed.
2. Check if the sync will fit in the new window, if not issue a
wait_barrier() and set cluster_sync_low to sector_nr.
3. Set cluster_sync_high to cluster_sync_low + resync_window.
4. Send a message to all nodes so they may add it in their suspension
list.
bitmap_cond_end_sync is modified to allow to force a sync inorder
to get the curr_resync_completed uptodate with the sector passed.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Add BITMAP_MAJOR_CLUSTERED as 5, in order to prevent older kernels
to assemble a clustered device.
In order to maximize compatibility, the major version is set to
BITMAP_MAJOR_CLUSTERED *only* if the bitmap is clustered.
Added MD_FEATURE_CLUSTERED in order to return error for older
kernels which would assemble MD even if the bitmap is corrupted.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
process_suspend_info - which handles the RESYNCING request - must not
reply until all writes which were initiated before the request arrived,
have completed.
As a by-product, all process_* functions now take mddev as their
first arguement making it uniform.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Pull scheduler fix from Thomas Gleixner:
"Fix a long standing state race in finish_task_switch()"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Fix TASK_DEAD race in finish_task_switch()
Pull perf fix from Thomas Glexiner:
"Fix build breakage on powerpc in perf tools"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix build break on powerpc due to sample_reg_masks
Pull maintainer email update from Thomas Gleixner:
"Change Matt Fleming's email address in the maintainers file"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
MAINTAINERS: Change Matt Fleming's email address
Pull irq fixes from Thomas Gleixner:
"Three trivial commits:
- Fix a kerneldoc regression
- Export handle_bad_irq to unbreak a driver in next
- Add an accessor for the of_node field so refactoring in next does
not depend on merge ordering"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqdomain: Add an accessor for the of_node field
genirq: Fix handle_bad_irq kerneldoc comment
genirq: Export handle_bad_irq
Pull SCSI fixes from James Bottomley:
"This is a set of three bug fixes, two of which are regressions from
recent updates (the 3ware one from 4.1 and the device handler fixes
from 4.2)"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
3w-9xxx: don't unmap bounce buffered commands
scsi_dh: Use the correct module name when loading device handler
libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop
NeilBrown
Guoqing Jiang
Goldwyn Rodrigues
Linus Torvalds