linux-toradex.git/drivers/md, branch v2.6.16.42

Make 'repair' actually work for raid1.

2007-02-03T00:56:23+00:00

When 'repair' finds a block that is different one the various
parts of the mirror. it is meant to write a chosen good version
to the others.  However it currently writes out the original data
to each. The memcpy to make all the data the same is missing.

Also correct a test so that 'repair' causes a repair, rather than
anything other then 'repair'.

Signed-off-by: Neil Brown 
Signed-off-by: Adrian Bunk

md: Fix md grow/size code to correctly find the maximum available space

2006-12-15T00:48:58+00:00

An md array can be asked to change the amount of each device that it is using,
and in particular can be asked to use the maximum available space.  This
currently only works if the first device is not larger than the rest.  As
'size' gets changed and so 'fit' becomes wrong.  So check if a 'fit' is
required early and don't corrupt it.

Signed-off-by: Doug Ledford 
Signed-off-by: Neil Brown 
Signed-off-by: Adrian Bunk

dm crypt: Fix data corruption with dm-crypt over RAID5

2006-12-15T00:21:59+00:00

Fix corruption issue with dm-crypt on top of software raid5. Cancelled
readahead bio's that report no error, just have BIO_UPTODATE cleared
were reported as successful reads to the higher layers (and leaving
random content in the buffer cache). Already fixed in 2.6.19.

Signed-off-by: Christophe Saout 
Signed-off-by: Adrian Bunk

dm snapshot: fix metadata writing when suspending

2006-12-14T22:09:07+00:00

When suspending a device-mapper device, dm_suspend() sleeps until all
necessary I/O is completed.  This state is triggered by a callback from
persistent_commit().  But some I/O can still be issued *after* the callback
(to prepare the next metadata area for use if the current one is full).  This
patch delays the callback until after that I/O is complete.

Signed-off-by: Mark McLoughlin 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Adrian Bunk

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

2006-12-14T22:08:32+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 
Signed-off-by: Adrian Bunk

dm: mirror sector offset fix

2006-12-14T22:07:54+00:00

The device-mapper core does not perform any remapping of bios before passing
them to the targets.  If a particular mapping begins part-way into a device,
targets obtain the sector relative to the start of the mapping by subtracting
ti->begin.

The dm-raid1 target didn't do this everywhere: this patch fixes it, taking
care to subtract ti->begin exactly once for each bio.

Signed-off-by: Neil Brown 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Adrian Bunk

dm: add module ref counting

2006-12-14T22:07:12+00:00

The reference counting on dm-mod is zero if no mapped devices are open.  This
is incorrect, and can lead to an oops if the module is unloaded while mapped
devices exist.

This patch claims a reference to the module whenever a device is created, and
drops it again when the device is freed.

Devices must be removed before dm-mod is unloaded.

Signed-off-by: Jeff Mahoney 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Adrian Bunk

dm snapshot: unify chunk_size

2006-12-14T22:04:35+00:00

Persistent snapshots currently store a private copy of the chunk size.
Userspace also supplies the chunk size when loading a snapshot.  Ensure
consistency by only storing the chunk_size in one place instead of two.

Currently the two sizes will differ if the chunk size supplied by userspace
does not match the chunk size an existing snapshot actually uses.  Amongst
other problems, this causes an incorrect 'percentage full' to be reported.

The patch ensures consistency by only storing the chunk_size in one place,
removing it from struct pstore.  Some initialisation is delayed until the
correct chunk_size is known.  If read_header() discovers that the wrong chun
size was supplied, the 'area' buffer (which the header already got read into
is reinitialised to the correct size.

Signed-off-by: Alasdair G Kergon 
Signed-off-by: Adrian Bunk

dm: BUG/OOPS fix

2006-12-14T22:02:33+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 0000000
0
 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 
Signed-off-by: Adrian Bunk

drivers/md/md.c: update START_ARRAY printk

2006-11-08T07:19:14+00:00

START_ARRAY will not be removed in 2.6.16, therefore replace the date
reference with a kernel version reference.

Signed-off-by: Adrian Bunk