linux-toradex.git/drivers/md, branch v2.6.18

[PATCH] md: Fix issues with referencing rdev in md/raid1

2006-09-01T18:39:08+00:00

We need to be careful when referencing mirrors[i].rdev.  It can disappear
under us at various times.

So:
  fix a couple of problem places.
  comment a couple of non-problem places
  move an 'atomic_add' which deferences rdev down a little
    way to some where where it is sure to not be NULL.

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: fix recent breakage of md/raid1 array checking

2006-08-27T18:01:31+00:00

A recent patch broke the ability to do a user-request check of a raid1.
This patch fixes the breakage and also moves a comment that was dislocated
by the same patch.

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: avoid backward event updates in md superblock when degraded.

2006-08-27T18:01:31+00:00

If we
  - shut down a clean array,
  - restart with one (or more) drive(s) missing
  - make some changes
  - pause, so that they array gets marked 'clean',
the event count on the superblock of included drives
will be the same as that of the removed drives.
So adding the removed drive back in will cause it
to be included with no resync.

To avoid this, we only update the eventcount backwards when the array
is not degraded.  In this case there can (should) be no non-connected
drives that we can get confused with, and this is the particular case
where updating-backwards is valuable.

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] dm: Fix deadlock under high i/o load in raid1 setup.

2006-08-27T18:01:28+00:00

On an nForce4-equipped machine with two SATA disk in raid1 setup using dmraid,
we experienced frequent deadlock of the system under high i/o load.  'cat
/dev/zero > ~/zero' was the most reliable way to reproduce them: Randomly
after a few GB, 'cp' would be left in 'D' state along with kjournald and
kmirrord.  The functions cp and kjournald were blocked in did vary, but
kmirrord's wchan always pointed to 'mempool_alloc()'.  We've seen this pattern
on 2.6.15 and 2.6.17 kernels.  http://lkml.org/lkml/2005/4/20/142 indicates
that this problem has been around even before.

So much for the facts, here's my interpretation: mempool_alloc() first tries
to atomically allocate the requested memory, or falls back to hand out
preallocated chunks from the mempool.  If both fail, it puts the calling
process (kmirrord in this case) on a private waitqueue until somebody refills
the pool.  Where the only 'somebody' is kmirrord itself, so we have a
deadlock.

I worked around this problem by falling back to a (blocking) kmalloc when
before kmirrord would have ended up on the waitqueue.  This defeats part of
the benefits of using the mempool, but at least keeps the system running.  And
it could be done with a two-line change.  Note that mempool_alloc() clears the
GFP_NOIO flag internally, and only uses it to decide whether to wait or return
an error if immediate allocation fails, so the attached patch doesn't change
behaviour in the non-deadlocking case.  Path is against current git
(2.6.18-rc4), but should apply to earlier versions as well.  I've tested on
2.6.15, where this patch makes the difference between random lockup and a
stable system.

Signed-off-by: Daniel Kobras 
Acked-by: Alasdair G Kergon 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] dm: BUG/OOPS fix

2006-08-14T19:54:29+00:00

Fix BUG I tripped on while testing failover and multipathing.

BUG shows up on error path in multipath_ctr() when parse_priority_group()
fails after returning at least once without error.  The fix is to
initialize m->ti early - just after alloc()ing it.

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
 printing eip:
c027c3d2
*pde = 00000000
Oops: 0000 [#3]
Modules linked in: qla2xxx ext3 jbd mbcache sg ide_cd cdrom floppy
CPU:    0
EIP:    0060:[]    Not tainted VLI
EFLAGS: 00010202   (2.6.17.3 #1)
EIP is at dm_put_device+0xf/0x3b
eax: 00000001   ebx: ee4fcac0   ecx: 00000000   edx: ee4fcac0
esi: ee4fc4e0   edi: ee4fc4e0   ebp: 00000000   esp: c5db3e78
ds: 007b   es: 007b   ss: 0068
Process multipathd (pid: 15912, threadinfo=c5db2000 task=ef485a90)
Stack: ec4eda40 c02816bd ee4fc4c0 00000000 f7e89498 f883e0bc c02816f6 f7e89480
       f7e8948c c0281801 ffffffea f7e89480 f883e080 c0281ffe 00000001 00000000
       00000004 dfe9cab8 f7a693c0 f883e080 f883e0c0 ca4b99c0 c027c6ee 01400000
Call Trace:
  free_pgpaths+0x31/0x45   free_priority_group+0x25/0x2e
  free_multipath+0x35/0x67   multipath_ctr+0x123/0x12d
  dm_table_add_target+0x11e/0x18b   populate_table+0x8a/0xaf
  table_load+0x52/0xf9   ctl_ioctl+0xca/0xfc
  table_load+0x0/0xf9   do_ioctl+0x3e/0x43
  vfs_ioctl+0x16c/0x178   sys_ioctl+0x48/0x60
  syscall_call+0x7/0xb
Code: 97 f0 00 00 00 89 c1 83 c9 01 80 e2 01 0f 44 c1 88 43 14 8b 04 24 59 5b 5e 5f 5d c3 53 89 c1 89 d3 ff 4a 08 0f 94 c0 84 c0 74 2a <8b> 01 8b 10 89 d8 e8 f6 fb ff ff 8b 03 8b 53 04 89 50 04 89 02
EIP: [] dm_put_device+0xf/0x3b SS:ESP 0068:c5db3e78

Signed-off-by: Michal Miroslaw 
Acked-by: Alasdair G Kergon 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

[PATCH] md: Fix a bug that recently crept into md/linear

2006-08-06T15:57:46+00:00

A recent patch that allowed linear arrays to be reconfigured on-line
allowed in a bug which results in divide by zero - not all
mddev->array_size were converted to conf->array_size.

This patch finished the conversion and fixed the bug.

The offending patch was commit 7c7546ccf6463edbeee8d9aac6de7be1cd80d08a.

Thanks to Simon Kirby  for the bug report.

Cc: Simon Kirby 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: fix oops in error-handling

2006-07-10T20:24:17+00:00

During early MD setup (superblock reading), we don't have a personality yet.
But the error-handling code tries to dereference mddev->pers.  Fix.

Acked-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: include sector number in messages about corrected read errors

2006-07-10T20:24:17+00:00

This is generally useful, but particularly helps see if it is the same sector
that always needs correcting, or different ones.

[akpm@osdl.org: fix printk warnings]
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: require CAP_SYS_ADMIN for (re-)configuring md devices via sysfs

2006-07-10T20:24:17+00:00

The ioctl requires CAP_SYS_ADMIN, so sysfs should too.  Note that we don't
require CAP_SYS_ADMIN for reading attributes even though the ioctl does.
There is no reason to limit the read access, and much of the information is
already available via /proc/mdstat

Cc: Chris Wright 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: unify usage of symbolic names for perms

2006-07-10T20:24:17+00:00

Some places we use number (0660) someplaces names (S_IRUGO).  Change all
numbers to be names, and change 0655 to be what it should be.

Also make some formatting more consistent.

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds