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  1. 10 10月, 2008 15 次提交
  3. 01 10月, 2008 3 次提交
    • C
      dm mpath: add missing path switching locking · 7253a334
      由 Chandra Seetharaman 提交于 
      Moving the path activation to workqueue along with scsi_dh patches introduced
a race. It is due to the fact that the current_pgpath (in the multipath data
structure) can be modified if changes happen in any of the paths leading to
the lun. If the changes lead to current_pgpath being set to NULL, then it
leads to the invalid access which results in the panic below.

This patch fixes that by storing the pgpath to activate in the multipath data
structure and properly protecting it.

Note that if activate_path is called twice in succession with different pgpath,
with the second one being called before the first one is done, then activate
path will be called twice for the second pgpath, which is fine.

Unable to handle kernel paging request for data at address 0x00000020
Faulting instruction address: 0xd000000000aa1844
cpu 0x1: Vector: 300 (Data Access) at [c00000006b987a80]
    pc: d000000000aa1844: .activate_path+0x30/0x218 [dm_multipath]
    lr: c000000000087a2c: .run_workqueue+0x114/0x204
    sp: c00000006b987d00
   msr: 8000000000009032
   dar: 20
 dsisr: 40000000
  current = 0xc0000000676bb3f0
  paca    = 0xc0000000006f3680
    pid   = 2528, comm = kmpath_handlerd
enter ? for help
[c00000006b987da0] c000000000087a2c .run_workqueue+0x114/0x204
[c00000006b987e40] c000000000088b58 .worker_thread+0x120/0x144
[c00000006b987f00] c00000000008ca70 .kthread+0x78/0xc4
[c00000006b987f90] c000000000027cc8 .kernel_thread+0x4c/0x68
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      7253a334
    • M
      dm: cope with access beyond end of device in dm_merge_bvec · b01cd5ac
      由 Mikulas Patocka 提交于 
      If for any reason dm_merge_bvec() is given an offset beyond the end of the
device, avoid an oops and always allow one page to be added to an empty bio.
We'll reject the I/O later after the bio is submitted.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      b01cd5ac
    • M
      dm: always allow one page in dm_merge_bvec · 5037108a
      由 Mikulas Patocka 提交于 
      Some callers assume they can always add at least one page to an empty bio,
so dm_merge_bvec should not return 0 in this case: we'll reject the I/O
later after the bio is submitted.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      5037108a
  5. 19 9月, 2008 1 次提交
    • N
      md: Don't wait UNINTERRUPTIBLE for other resync to finish · 9744197c
      由 NeilBrown 提交于 
      When two md arrays share some block device (e.g each uses different
partitions on the one device), a resync of one array will wait for
the resync on the other to finish.

This can be a long time and as it currently waits TASK_UNINTERRUPTIBLE,
the softlockup code notices and complains.

So use TASK_INTERRUPTIBLE instead and make sure to flush signals
before calling schedule.
Signed-off-by: NNeilBrown <neilb@suse.de>
      9744197c
  7. 01 9月, 2008 2 次提交
    • N
      Fix problem with waiting while holding rcu read lock in md/bitmap.c · b2d2c4ce
      由 NeilBrown 提交于 
      A recent patch to protect the rdev list with rcu locking leaves us
with a problem because we can sleep on memalloc while holding the
rcu lock.

The rcu lock is only needed while walking the linked list as
uninteresting devices (failed or spares) can be removed at any time.

So only take the rcu lock while actually walking the linked list.
Take a refcount on the rdev during the time when we drop the lock
and do the memalloc to start IO.
When we return to the locked code, all the interesting devices
on the list will not have moved, so we can simply use
list_for_each_continue_rcu to pick up where we left off.
Signed-off-by: NNeilBrown <neilb@suse.de>
      b2d2c4ce
    • N
      Remove invalidate_partition call from do_md_stop. · 271f5a9b
      由 NeilBrown 提交于 
      When stopping an md array, or just switching to read-only, we
currently call invalidate_partition while holding the mddev lock.
The main reason for this is probably to ensure all dirty buffers
are flushed (invalidate_partition calls fsync_bdev).

However if any dirty buffers are found, it will almost certainly cause
a deadlock as starting writeout will require an update to the
superblock, and performing that updates requires taking the mddev
lock - which is already held.

This deadlock can be demonstrated by running "reboot -f -n" with
a root filesystem on md/raid, and some dirty buffers in memory.

All other calls to stop an array should already happen after a flush.
The normal sequence is to stop using the array (e.g. umount) which
will cause __blkdev_put to call sync_blockdev.  Then open the
array and issue the STOP_ARRAY ioctl while the buffers are all still
clean.

So this invalidate_partition is normally a no-op, except for one case
where it will cause a deadlock.

So remove it.

This patch possibly addresses the regression recored in
   http://bugzilla.kernel.org/show_bug.cgi?id=11460
and
   http://bugzilla.kernel.org/show_bug.cgi?id=11452

though it isn't yet clear how it ever worked.
Signed-off-by: NNeilBrown <neilb@suse.de>
      271f5a9b
  9. 08 8月, 2008 1 次提交
  11. 05 8月, 2008 6 次提交
    • N
      Allow raid10 resync to happening in larger chunks. · 0310fa21
      由 NeilBrown 提交于 
      The raid10 resync/recovery code currently limits the amount of
in-flight resync IO to 2Meg.  This was copied from raid1 where
it seems quite adequate.  However for raid10, some layouts require
a bit of seeking to perform a resync, and allowing a larger buffer
size means that the seeking can be significantly reduced.

There is probably no real need to limit the amount of in-flight
IO at all.  Any shortage of memory will naturally reduce the
amount of buffer space available down to a set minimum, and any
concurrent normal IO will quickly cause resync IO to back off.

The only problem would be that normal IO has to wait for all resync IO
to finish, so a very large amount of resync IO could cause unpleasant
latency when normal IO starts up.

So: increase RESYNC_DEPTH to allow 32Meg of buffer (if memory is
available) which seems to be a good amount.  Also reduce the amount
of memory reserved as there is no need to keep 2Meg just for resync if
memory is tight.

Thanks to Keld for the suggestion.

Cc: Keld Jørn Simonsen <keld@dkuug.dk>
Signed-off-by: NNeilBrown <neilb@suse.de>
      0310fa21
    • N
      Allow faulty devices to be removed from a readonly array. · c89a8eee
      由 NeilBrown 提交于 
      Removing faulty devices from an array is a two stage process.
First the device is moved from being a part of the active array
to being similar to a spare device.  Then it can be removed
by a request from user space.

The first step is currently not performed for read-only arrays,
so the second step can never succeed.

So allow readonly arrays to remove failed devices (which aren't
blocked).
Signed-off-by: NNeilBrown <neilb@suse.de>
      c89a8eee
    • N
      Don't let a blocked_rdev interfere with read request in raid5/6 · ac4090d2
      由 NeilBrown 提交于 
      When we have externally managed metadata, we need to mark a failed
device as 'Blocked' and not allow any writes until that device
have been marked as faulty in the metadata and the Blocked flag has
been removed.

However it is perfectly OK to allow read requests when there is a
Blocked device, and with a readonly array, there may not be any
metadata-handler watching for blocked devices.

So in raid5/raid6 only allow a Blocked device to interfere with
Write request or resync.  Read requests go through untouched.

raid1 and raid10 already differentiate between read and write
properly.
Signed-off-by: NNeilBrown <neilb@suse.de>
      ac4090d2
    • N
      Fail safely when trying to grow an array with a write-intent bitmap. · dba034ee
      由 NeilBrown 提交于 
      We cannot currently change the size of a write-intent bitmap.
So if we change the size of an array which has such a bitmap, it
tries to set bits beyond the end of the bitmap.

For now, simply reject any request to change the size of an array
which has a bitmap.  mdadm can remove the bitmap and add a new one
after the array has changed size.
Signed-off-by: NNeilBrown <neilb@suse.de>
      dba034ee
    • N
      Restore force switch of md array to readonly at reboot time. · 2b25000b
      由 NeilBrown 提交于 
      A recent patch allowed do_md_stop to know whether it was being called
via an ioctl or not, and thus where to allow for an extra open file
descriptor when checking if it is in use.
This broke then switch to readonly performed by the shutdown notifier,
which needs to work even when the array is still (apparently) active
(as md doesn't get told when the filesystem becomes readonly).

So restore this feature by pretending that there can be lots of
file descriptors open, but we still want do_md_stop to switch to
readonly.
Signed-off-by: NNeilBrown <neilb@suse.de>
      2b25000b
    • N
      Make writes to md/safe_mode_delay immediately effective. · 19052c0e
      由 NeilBrown 提交于 
      If we reduce the 'safe_mode_delay', it could still wait for the old
delay to completely expire before doing anything about safe_mode.
Thus the effect if the change is delayed.

To make the effect more immediate, run the timeout function
immediately if the delay was reduced.  This may cause it to run
slightly earlier that required, but that is the safer option.
Signed-off-by: NNeilBrown <neilb@suse.de>
      19052c0e
  13. 02 8月, 2008 1 次提交
  15. 01 8月, 2008 2 次提交
  17. 29 7月, 2008 2 次提交
  19. 27 7月, 2008 1 次提交
  21. 24 7月, 2008 3 次提交
  23. 21 7月, 2008 3 次提交