Commit Graph

1383 Commits

Author SHA1 Message Date
Linus Torvalds 355bbd8cb8 Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block: (29 commits)
  block: use blkdev_issue_discard in blk_ioctl_discard
  Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads
  block: don't assume device has a request list backing in nr_requests store
  block: Optimal I/O limit wrapper
  cfq: choose a new next_req when a request is dispatched
  Seperate read and write statistics of in_flight requests
  aoe: end barrier bios with EOPNOTSUPP
  block: trace bio queueing trial only when it occurs
  block: enable rq CPU completion affinity by default
  cfq: fix the log message after dispatched a request
  block: use printk_once
  cciss: memory leak in cciss_init_one()
  splice: update mtime and atime on files
  block: make blk_iopoll_prep_sched() follow normal 0/1 return convention
  cfq-iosched: get rid of must_alloc flag
  block: use interrupts disabled version of raise_softirq_irqoff()
  block: fix comment in blk-iopoll.c
  block: adjust default budget for blk-iopoll
  block: fix long lines in block/blk-iopoll.c
  block: add blk-iopoll, a NAPI like approach for block devices
  ...
2009-09-14 17:55:15 -07:00
Linus Torvalds 39695224bd Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (209 commits)
  [SCSI] fix oops during scsi scanning
  [SCSI] libsrp: fix memory leak in srp_ring_free()
  [SCSI] libiscsi, bnx2i: make bound ep check common
  [SCSI] libiscsi: add completion function for drivers that do not need pdu processing
  [SCSI] scsi_dh_rdac: changes for rdac debug logging
  [SCSI] scsi_dh_rdac: changes to collect the rdac debug information during the initialization
  [SCSI] scsi_dh_rdac: move the init code from rdac_activate to rdac_bus_attach
  [SCSI] sg: fix oops in the error path in sg_build_indirect()
  [SCSI] mptsas : Bump version to 3.04.12
  [SCSI] mptsas : FW event thread and scsi mid layer deadlock in SYNCHRONIZE CACHE command
  [SCSI] mptsas : Send DID_NO_CONNECT for pending IOs of removed device
  [SCSI] mptsas : PAE Kernel more than 4 GB kernel panic
  [SCSI] mptsas : NULL pointer on big endian systems causing Expander not to tear off
  [SCSI] mptsas : Sanity check for phyinfo is added
  [SCSI] scsi_dh_rdac: Add support for Sun StorageTek ST2500, ST2510 and ST2530
  [SCSI] pmcraid: PMC-Sierra MaxRAID driver to support 6Gb/s SAS RAID controller
  [SCSI] qla2xxx: Update version number to 8.03.01-k6.
  [SCSI] qla2xxx: Properly delete rports attached to a vport.
  [SCSI] qla2xxx: Correct various NPIV issues.
  [SCSI] qla2xxx: Correct qla2x00_eh_wait_on_command() to wait correctly.
  ...
2009-09-14 17:53:36 -07:00
Martin K. Petersen 3c5820c743 block: Optimal I/O limit wrapper
Implement blk_limits_io_opt() and make blk_queue_io_opt() a wrapper
around it. DM needs this to avoid poking at the queue_limits directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-14 08:24:52 +02:00
Nikanth Karthikesan a9327cac44 Seperate read and write statistics of in_flight requests
Currently, there is a single in_flight counter measuring the number of
requests in the request_queue. But some monitoring tools would like to
know how many read requests and write requests are in progress. Split the
current in_flight counter into two seperate counters for read and write.

This information is exported as a sysfs attribute, as changing the
currently available stat files would break the existing tools.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-14 08:24:52 +02:00
Jens Axboe 1f98a13f62 bio: first step in sanitizing the bio->bi_rw flag testing
Get rid of any functions that test for these bits and make callers
use bio_rw_flagged() directly. Then it is at least directly apparent
what variable and flag they check.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11 14:33:31 +02:00
Geert Uytterhoeven 0d03d59d9b md: Fix "strchr" [drivers/md/dm-log-userspace.ko] undefined!
Commit b8313b6da7 ("dm log: remove incorrect
field from userspace table output") added a call to strstr() with a
single-character "needle" string parameter.

Unfortunately some versions of gcc replace such calls to strstr() by calls
to strchr() behind our back.  This causes linking errors if strchr() is
defined as an inline function in <asm/string.h> (e.g. on m68k):

| WARNING: "strchr" [drivers/md/dm-log-userspace.ko] undefined!

Avoid this by explicitly calling strchr() instead.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-10 14:55:01 -07:00
Mikulas Patocka ae0b7448e9 dm snapshot: fix on disk chunk size validation
Fix some problems seen in the chunk size processing when activating a
pre-existing snapshot.

For a new snapshot, the chunk size can either be supplied by the creator
or a default value can be used.  For an existing snapshot, the
chunk size in the snapshot header on disk should always be used.

If someone attempts to load an existing snapshot and has the 'default
chunk size' option set, the kernel uses its default value even when it
is incorrect for the snapshot being loaded.  This patch ensures the
correct on-disk value is always used.

Secondly, when the code does use the chunk size stored on the disk it is
prudent to revalidate it, so the code can exit cleanly if it got
corrupted as happened in
https://bugzilla.redhat.com/show_bug.cgi?id=461506 .

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:43 +01:00
Mikulas Patocka 2defcc3fb4 dm exception store: split set_chunk_size
Break the function set_chunk_size to two functions in preparation for
the fix in the following patch.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:41 +01:00
Mikulas Patocka 61578dcd3f dm snapshot: fix header corruption race on invalidation
If a persistent snapshot fills up, a race can corrupt the on-disk header
which causes a crash on any future attempt to activate the snapshot
(typically while booting).  This patch fixes the race.

When the snapshot overflows, __invalidate_snapshot is called, which calls
snapshot store method drop_snapshot. It goes to persistent_drop_snapshot that
calls write_header. write_header constructs the new header in the "area"
location.

Concurrently, an existing kcopyd job may finish, call copy_callback
and commit_exception method, that goes to persistent_commit_exception.
persistent_commit_exception doesn't do locking, relying on the fact that
callbacks are single-threaded, but it can race with snapshot invalidation and
overwrite the header that is just being written while the snapshot is being
invalidated.

The result of this race is a corrupted header being written that can
lead to a crash on further reactivation (if chunk_size is zero in the
corrupted header).

The fix is to use separate memory areas for each.

See the bug: https://bugzilla.redhat.com/show_bug.cgi?id=461506

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:39 +01:00
Mikulas Patocka 02d2fd31de dm snapshot: refactor zero_disk_area to use chunk_io
Refactor chunk_io to prepare for the fix in the following patch.

Pass an area pointer to chunk_io and simplify zero_disk_area to use
chunk_io.  No functional change.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:37 +01:00
Jonathan Brassow 7ec23d5094 dm log: userspace add luid to distinguish between concurrent log instances
Device-mapper userspace logs (like the clustered log) are
identified by a universally unique identifier (UUID).  This
identifier is used to associate requests from the kernel to
a specific log in userspace.  The UUID must be unique everywhere,
since multiple machines may use this identifier when communicating
about a particular log, as is the case for cluster logs.

Sometimes, device-mapper/LVM may re-use a UUID.  This is the
case during pvmoves, when moving from one segment of an LV
to another, or when resizing a mirror, etc.  In these cases,
a new log is created with the same UUID and loaded in the
"inactive" slot.  When a device-mapper "resume" is issued,
the "live" table is deactivated and the new "inactive" table
becomes "live".  (The "inactive" table can also be removed
via a device-mapper 'clear' command.)

The above two issues were colliding.  More than one log was being
created with the same UUID, and there was no way to distinguish
between them.  So, sometimes the wrong log would be swapped
out during the exchange.

The solution is to create a locally unique identifier,
'luid', to go along with the UUID.  This new identifier is used
to determine exactly which log is being referenced by the kernel
when the log exchange is made.  The identifier is not
universally safe, but it does not need to be, since
create/destroy/suspend/resume operations are bound to a specific
machine; and these are the operations that make up the exchange.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
Jonathan Brassow d2b698644c dm raid1: do not allow log_failure variable to unset after being set
This patch fixes a bug which was triggering a case where the primary leg
could not be changed on failure even when the mirror was in-sync.

The case involves the failure of the primary device along with
the transient failure of the log device.  The problem is that
bios can be put on the 'failures' list (due to log failure)
before 'fail_mirror' is called due to the primary device failure.
Normally, this is fine, but if the log device failure is transient,
a subsequent iteration of the work thread, 'do_mirror', will
reset 'log_failure'.  The 'do_failures' function then resets
the 'in_sync' variable when processing bios on the failures list.
The 'in_sync' variable is what is used to determine if the
primary device can be switched in the event of a failure.  Since
this has been reset, the primary device is incorrectly assumed
to be not switchable.

The case has been seen in the cluster mirror context, where one
machine realizes the log device is dead before the other machines.
As the responsibilities of the server migrate from one node to
another (because the mirror is being reconfigured due to the failure),
the new server may think for a moment that the log device is fine -
thus resetting the 'log_failure' variable.

In any case, it is inappropiate for us to reset the 'log_failure'
variable.  The above bug simply illustrates that it can actually
hurt us.

Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:32 +01:00
Jonathan Brassow b8313b6da7 dm log: remove incorrect field from userspace table output
The output of 'dmsetup table' includes an internal field that should not
be there.  This patch removes it.  To make the fix simpler, we first
reorder a constructor argument

The 'device size' argument is generated internally.  Currently it is
placed as the last space-separated word of the constructor string.
However, we need to use a version of the string without this word, so we
move it to the beginning instead so it is trivial to skip past it.

We keep a copy of the arguments passed to userspace for creating a log,
just in case we need to resend them.  These are the same arguments that
are desired in the STATUSTYPE_TABLE request, except for one.  When
creating the userspace log, the userspace daemon must know the size of
the mirror, so that is added to the arguments given in the constructor
table.  We were printing this extra argument out as well, which is a
mistake.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:30 +01:00
Jonathan Brassow 4142a96917 dm log: fix userspace status output
Fix 'dmsetup table' output.

There is a missing ' ' at the end of the string causing two
words to run together.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:28 +01:00
Mike Snitzer 40bea43127 dm stripe: expose correct io hints
Set sensible I/O hints for striped DM devices in the topology
infrastructure added for 2.6.31 for userspace tools to
obtain via sysfs.

Add .io_hints to 'struct target_type' to allow the I/O hints portion
(io_min and io_opt) of the 'struct queue_limits' to be set by each
target and implement this for dm-stripe.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:25 +01:00
Mike Snitzer a963a95622 dm table: add more context to terse warning messages
A couple of recent warning messages make it difficult for the reader to
determine exactly what is wrong.  This patch adds more information to
those messages.

The messages were added by these commits:
  5dea271b6d ("dm table: pass correct dev area size
to device_area_is_valid")
  ea9df47cc9 ("dm table: fix blk_stack_limits arg
to use bytes not sectors")

The patch also corrects references to logical_block_size in printk format
strings from %hu to %u.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:24 +01:00
Mikulas Patocka f6a1ed1086 dm table: fix queue_limit checking device iterator
The logic to check for valid device areas is inverted relative to proper
use with iterate_devices.

The iterate_devices method calls its callback for every underlying
device in the target.  If any callback returns non-zero, iterate_devices
exits immediately.  But the callback device_area_is_valid() returns 0 on
error and 1 on success.  The overall effect without is that an error is
issued only if every device is invalid.

This patch renames device_area_is_valid to device_area_is_invalid and
inverts the logic so that one invalid device is sufficient to raise
an error.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:22 +01:00
Mike Snitzer 8811f46c1f dm snapshot: implement iterate devices
Implement the .iterate_devices for the origin and snapshot targets.
dm-snapshot's lack of .iterate_devices resulted in the inability to
properly establish queue_limits for both targets.

With 4K sector drives: an unfortunate side-effect of not establishing
proper limits in either targets' DM device was that IO to the devices
would fail even though both had been created without error.

Commit af4874e03e ("dm target:s introduce
iterate devices fn") in 2.6.31-rc1 should have implemented .iterate_devices
for dm-snap.c's origin and snapshot targets.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:19 +01:00
Kiyoshi Ueda a77e28c7e1 dm multipath: fix oops when request based io fails when no paths
The patch posted at http://marc.info/?l=dm-devel&m=124539787228784&w=2
which was merged into cec47e3d4a ("dm:
prepare for request based option") introduced a regression in
request-based dm.

If map_request() calls dm_kill_unmapped_request() to complete a cloned
bio without dispatching it, clone->bio is still set when
dm_end_request() is called and the BUG_ON(clone->bio) is incorrect.

The patch fixes this bug by freeing bio in dm_end_request() if the clone
has bio.  I've redone my tests to cover all I/O paths and confirmed
there's no other regression.

Here is the oops I hit in request-based dm when I do I/O to a multipath
device which doesn't have any active path nor queue_if_no_path setting:

------------[ cut here ]------------
kernel BUG at /root/2.6.31-rc4.rqdm/drivers/md/dm.c:828!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
CPU 1
Modules linked in: autofs4 sunrpc cpufreq_ondemand acpi_cpufreq dm_mirror dm_region_hash dm_log dm_service_time dm_multipath scsi_dh dm_mod video output sbs sbshc battery ac sg sr_mod e1000e button cdrom serio_raw rtc_cmos rtc_core rtc_lib piix lpfc scsi_transport_fc ata_piix libata megaraid_sas sd_mod scsi_mod crc_t10dif ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: microcode]
Pid: 7, comm: ksoftirqd/1 Not tainted 2.6.31-rc4.rqdm #1 Express5800/120Lj [N8100-1417]
RIP: 0010:[<ffffffffa023629d>]  [<ffffffffa023629d>] dm_softirq_done+0xbd/0x100 [dm_mod]
RSP: 0018:ffff8800280a1f08  EFLAGS: 00010282
RAX: ffffffffa02544e0 RBX: ffff8802aa1111d0 RCX: ffff8802aa1111e0
RDX: ffff8802ab913e70 RSI: 0000000000000000 RDI: ffff8802ab913e70
RBP: ffff8800280a1f28 R08: ffffc90005457040 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffb
R13: ffff8802ab913e88 R14: ffff8802ab9c1438 R15: 0000000000000100
FS:  0000000000000000(0000) GS:ffff88002809e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000003d54a98640 CR3: 000000029f0a1000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process ksoftirqd/1 (pid: 7, threadinfo ffff8802ae50e000, task ffff8802ae4f8040)
Stack:
 ffff8800280a1f38 0000000000000020 ffffffff814f30a0 0000000000000004
<0> ffff8800280a1f58 ffffffff8116b245 ffff8800280a1f38 ffff8800280a1f38
<0> ffff8800280a1f58 0000000000000001 ffff8800280a1fa8 ffffffff810477bc
Call Trace:
 <IRQ>
 [<ffffffff8116b245>] blk_done_softirq+0x75/0x90
 [<ffffffff810477bc>] __do_softirq+0xcc/0x210
 [<ffffffff81047170>] ? ksoftirqd+0x0/0x110
 [<ffffffff8100ce7c>] call_softirq+0x1c/0x50
 <EOI>
 [<ffffffff8100e785>] do_softirq+0x65/0xa0
 [<ffffffff81047170>] ? ksoftirqd+0x0/0x110
 [<ffffffff810471e0>] ksoftirqd+0x70/0x110
 [<ffffffff81059559>] kthread+0x99/0xb0
 [<ffffffff8100cd7a>] child_rip+0xa/0x20
 [<ffffffff8100c73c>] ? restore_args+0x0/0x30
 [<ffffffff810594c0>] ? kthread+0x0/0xb0
 [<ffffffff8100cd70>] ? child_rip+0x0/0x20
Code: 44 89 e6 48 89 df e8 23 fb f2 e0 be 01 00 00 00 4c 89 f7 e8 f6 fd ff ff 5b 41 5c 41 5d 41 5e c9 c3 4c 89 ef e8 85 fe ff ff eb ed <0f> 0b eb fe 41 8b 85 dc 00 00 00 48 83 bb 10 01 00 00 00 89 83
RIP  [<ffffffffa023629d>] dm_softirq_done+0xbd/0x100 [dm_mod]
 RSP <ffff8800280a1f08>
---[ end trace 16af0a1d8542da55 ]---

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:16 +01:00
Chandra Seetharaman 2bfd2e1337 [SCSI] scsi_dh: Use scsi_dh_set_params() in multipath.
Use scsi_dh_set_params() set parameters provided. Save the parameters in
parse_hw_handler() and use it in parse_path().

Reported-by: Eddie Williams <Eddie.Williams@steeleye.com>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Tested-by: Eddie Williams <Eddie.Williams@steeleye.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22 17:52:15 -05:00
Linus Torvalds 435a71d9ef Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  Fix new incorrect error return from do_md_stop.
2009-08-18 13:54:08 -07:00
NeilBrown 80ffb3ccea Fix new incorrect error return from do_md_stop.
Recent commit c8c00a6915
changed the exit paths in do_md_stop and was not quite
careful enough.  There is one path were 'err' now needs
to be cleared but it isn't.
So setting an array to readonly (with mdadm --readonly) will
work, but will incorrectly report and error: ENXIO.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-18 10:35:26 +10:00
Randy Dunlap 894ef820b1 dm-log-userspace: fix printk format warning
drivers/md/dm-log-userspace-transfer.c:110: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'size_t'

Previously posted and acked, but apparently lost.
http://lkml.indiana.edu/hypermail/linux/kernel/0906.2/02074.html

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: dm-devel@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-16 08:35:58 -07:00
NeilBrown 4d484a4a7a md: allow upper limit for resync/reshape to be set when array is read-only
Normally we only allow the upper limit for a reshape to be decreased
when the array not performing a sync/recovery/reshape, otherwise there
could be races.  But if an array is part-way through a reshape when it
is assembled the reshape is started immediately leaving no window
to set an upper bound.

If the array is started read-only, the reshape will be suspended until
the array becomes writable, so that provides a window during which it
is perfectly safe to reduce the upper limit of a reshape.

So: allow the upper limit (sync_max) to be reduced even if the reshape
thread is running, as long as the array is still read-only.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:41:50 +10:00
NeilBrown 1a67dde0ab md/raid5: Properly remove excess drives after shrinking a raid5/6
We were removing the drives, from the array, but not
removing symlinks from /sys/.... and not marking the device
as having been removed.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:41:49 +10:00
NeilBrown a639755cf8 md/raid5: make sure a reshape restarts at the correct address.
This "if" don't allow for the possibility that the number of devices
doesn't change, and so sector_nr isn't set correctly in that case.
So change '>' to '>='.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:13:00 +10:00
NeilBrown 67ac6011db md/raid5: allow new reshape modes to be restarted in the middle.
md/raid5 doesn't allow a reshape to restart if it involves writing
over the same part of disk that it would be reading from.
This happens at the beginning of a reshape that increases the number
of devices, at the end of a reshape that decreases the number of
devices, and continuously for a reshape that does not change the
number of devices.

The current code is correct for the "increase number of devices"
case as the critical section at the start is handled by userspace
performing a backup.

It does not work for reducing the number of devices, or the
no-change case.
For 'reducing', we need to invert the test.  For no-change we cannot
really be sure things will be safe, so simply require the array
to be read-only, which is how the user-space code which carefully
starts such arrays works.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:06:24 +10:00
NeilBrown 51d5668cb2 md: never advance 'events' counter by more than 1.
When assembling arrays, md allows two devices to have different event
counts as long as the difference is only '1'.  This is to cope with
a system failure between updating the metadata on two difference
devices.

However there are currently times when we update the event count by
2.  This was done to keep the event count even when the array is clean
and odd when it is dirty, which allows us to avoid writing common
update to spare devices and so allow those spares to go to sleep.

This is bad for the above reason.  So change it to never increase by
two.  This means that the alignment between 'odd/even' and
'clean/dirty' might take a little longer to attain, but that is only a
small cost.  The spares will get a few more updates but that will
still be spared (;-) most updates and can still go to sleep.

Prior to this patch there was a small chance that after a crash an
array would fail to assemble due to the overly large event count
mismatch.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 09:54:02 +10:00
NeilBrown c8c00a6915 Remove deadlock potential in md_open
A recent commit:
  commit 449aad3e25

introduced the possibility of an A-B/B-A deadlock between
bd_mutex and reconfig_mutex.

__blkdev_get holds bd_mutex while calling md_open which takes
   reconfig_mutex,
do_md_run is always called with reconfig_mutex held, and it now
   takes bd_mutex in the call the revalidate_disk.

This potential deadlock was not caught by lockdep due to the
use of mutex_lock_interruptible_nexted which was introduced
by
   commit d63a5a74de
do avoid a warning of an impossible deadlock.

It is quite possible to split reconfig_mutex in to two locks.
One protects the array data structures while it is being
reconfigured, the other ensures that an array is never even partially
open while it is being deactivated.
In particular, the second lock prevents an open from completing
between the time when do_md_stop checks if there are any active opens,
and the time when the array is either set read-only, or when ->pers is
set to NULL.  So we can be certain that no IO is in flight as the
array is being destroyed.

So create a new lock, open_mutex, just to ensure exclusion between
'open' and 'stop'.

This avoids the deadlock and also avoids the lockdep warning mentioned
in commit d63a5a74d

Reported-by: "Mike Snitzer" <snitzer@gmail.com>
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-10 12:50:52 +10:00
NeilBrown 449aad3e25 md: Use revalidate_disk to effect changes in size of device.
As revalidate_disk calls check_disk_size_change, it will cause
any capacity change of a gendisk to be propagated to the blockdev
inode.  So use that instead of mucking about with locks and
i_size_write.

Also add a call to revalidate_disk in do_md_run and a few other places
where the gendisk capacity is changed.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:58 +10:00
NeilBrown 64bd660b51 md: allow raid5_quiesce to work properly when reshape is happening.
The ->quiesce method is not supposed to stop resync/recovery/reshape,
just normal IO.
But in raid5 we don't have a way to know which stripes are being
used for normal IO and which for resync etc, so we need to wait for
all stripes to be idle to be sure that all writes have completed.

However reshape keeps at least some stripe busy for an extended period
of time, so a call to raid5_quiesce can block for several seconds
needlessly.
So arrange for reshape etc to pause briefly while raid5_quiesce is
trying to quiesce the array so that the active_stripes count can
drop to zero.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:58 +10:00
NeilBrown e516402c0d md/raid5: set reshape_position correctly when reshape starts.
As the internal reshape_progress counter is the main driver
for reshape, the fact that reshape_position sometimes starts with the
wrong value has minimal effect.  It is visible in sysfs and that
is all.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:57 +10:00
NeilBrown 70471dafe3 md: Handle growth of v1.x metadata correctly.
The v1.x metadata does not have a fixed size and can grow
when devices are added.
If it grows enough to require an extra sector of storage,
we need to update the 'sb_size' to match.

Without this, md can write out an incomplete superblock with a
bad checksum, which will be rejected when trying to re-assemble
the array.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:57 +10:00
NeilBrown 3673f305fa md: avoid array overflow with bad v1.x metadata
We trust the 'desc_nr' field in v1.x metadata enough to use it
as an index in an array.  This isn't really safe.
So range-check the value first.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:56 +10:00
NeilBrown 3a981b03f3 md: when a level change reduces the number of devices, remove the excess.
When an array is changed from RAID6 to RAID5, fewer drives are
needed.  So any device that is made superfluous by the level
conversion must be marked as not-active.
For the RAID6->RAID5 conversion, this will be a drive which only
has 'Q' blocks on it.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:55 +10:00
Andre Noll ac5e7113e7 md: Push down data integrity code to personalities.
This patch replaces md_integrity_check() by two new public functions:
md_integrity_register() and md_integrity_add_rdev() which are both
personality-independent.

md_integrity_register() is called from the ->run and ->hot_remove
methods of all personalities that support data integrity.  The
function iterates over the component devices of the array and
determines if all active devices are integrity capable and if their
profiles match. If this is the case, the common profile is registered
for the mddev via blk_integrity_register().

The second new function, md_integrity_add_rdev() is called from the
->hot_add_disk methods, i.e. whenever a new device is being added
to a raid array. If the new device does not support data integrity,
or has a profile different from the one already registered, data
integrity for the mddev is disabled.

For raid0 and linear, only the call to md_integrity_register() from
the ->run method is necessary.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:47 +10:00
Dan Williams 95fc17aac4 md/raid6: release spare page at ->stop()
Add missing call to safe_put_page from stop() by unifying open coded
raid5_conf_t de-allocation under free_conf().

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-31 12:39:15 +10:00
Mike Snitzer 5dea271b6d dm table: pass correct dev area size to device_area_is_valid
Incorrect device area lengths are being passed to device_area_is_valid().

The regression appeared in 2.6.31-rc1 through commit
754c5fc7eb.

With the dm-stripe target, the size of the target (ti->len) was used
instead of the stripe_width (ti->len/#stripes).  An example of a
consequent incorrect error message is:

  device-mapper: table: 254:0: sdb too small for target

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-07-23 20:30:42 +01:00
Mike Snitzer a732c207d1 dm: remove queue next_ordered workaround for barriers
This patch removes DM's bio-based vs request-based conditional setting
of next_ordered.  For bio-based DM the next_ordered check is no longer a
concern (as that check is now in the __make_request path).  For
request-based DM the default of QUEUE_ORDERED_NONE is now appropriate.

bio-based DM was changed to work-around the previously misplaced
next_ordered check with this commit:
99360b4c18

request-based DM does not yet support barriers but reacted to the above
bio-based DM change with this commit:
5d67aa2366

The above changes are no longer needed given Neil Brown's recent fix to
put the next_ordered check in the __make_request path:
db64f680ba

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: NeilBrown <neilb@suse.de>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-07-23 20:30:40 +01:00
Mikulas Patocka 69885683d2 dm raid1: wake kmirrord when requeueing delayed bios after remote recovery
The recent commit 7513c2a761 (dm raid1:
add is_remote_recovering hook for clusters) changed do_writes() to
update the ms->writes list but forgot to wake up kmirrord to process it.

The rule is that when anything is being added on ms->reads, ms->writes
or ms->failures and the list was empty before we must call
wakeup_mirrord (for immediate processing) or delayed_wake (for delayed
processing).  Otherwise the bios could sit on the list indefinitely.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
CC: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-07-23 20:30:37 +01:00
Jens Axboe 8aa7e847d8 Fix congestion_wait() sync/async vs read/write confusion
Commit 1faa16d228 accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-10 20:31:53 +02:00
Joe Perches ad361c9884 Remove multiple KERN_ prefixes from printk formats
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics.  printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.

<level> is now included in the output on each additional use.

Remove all uses of multiple KERN_<level>s in formats.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-08 10:30:03 -07:00
Linus Torvalds 2027bd9f92 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cfq-iosched: remove redundant check for NULL cfqq in cfq_set_request()
  blocK: Restore barrier support for md and probably other virtual devices.
  block: get rid of queue-private command filter
  block: Create bip slabs with embedded integrity vectors
  cfq-iosched: get rid of the need for __GFP_NOFAIL in cfq_find_alloc_queue()
  cfq-iosched: move cfqq initialization out of cfq_find_alloc_queue()
  Trivial typo fixes in Documentation/block/data-integrity.txt.
2009-07-01 10:41:09 -07:00
Linus Torvalds 544ae5f96e Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: use interruptible wait when duration is controlled by userspace.
  md/raid5: suspend shouldn't affect read requests.
  md: tidy up error paths in md_alloc
  md: fix error path when duplicate name is found on md device creation.
  md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.
  md: Use new topology calls to indicate alignment and I/O sizes
2009-07-01 10:31:26 -07:00
Martin K. Petersen 7878cba9f0 block: Create bip slabs with embedded integrity vectors
This patch restores stacking ability to the block layer integrity
infrastructure by creating a set of dedicated bip slabs.  Each bip slab
has an embedded bio_vec array at the end.  This cuts down on memory
allocations and also simplifies the code compared to the original bvec
version.  Only the largest bip slab is backed by a mempool.  The pool is
contained in the bio_set so stacking drivers can ensure forward
progress.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.(none)>
2009-07-01 10:56:25 +02:00
NeilBrown e62e58a5ff md: use interruptible wait when duration is controlled by userspace.
User space can set various limits on an md array so that resync waits
when it gets to a certain point, or so that I/O is blocked for a short
while.
When md is waiting against one of these limit, it should use an
interruptible wait so as not to add to the load average, and so are
not to trigger a warning if the wait goes on for too long.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 13:15:35 +10:00
NeilBrown a5c308d4d1 md/raid5: suspend shouldn't affect read requests.
md allows write to regions on an array to be suspended temporarily.
This allows user-space to participate is aspects of reshape.
In particular, data can be copied with not risk of a race.
We should not be blocking read requests though, so don't.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 13:15:35 +10:00
NeilBrown 0909dc448c md: tidy up error paths in md_alloc
As the recent bug in md_alloc showed, having a single exit path for
unlocking and putting is a good idea.  So restructure md_alloc to have
a single mutex_unlock and mddev_put, and use gotos where necessary.

Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 12:27:21 +10:00
NeilBrown 1ec22eb2b4 md: fix error path when duplicate name is found on md device creation.
When an md device is created by name (rather than number) we need to
check that the name is not already in use.  If this check finds a
duplicate, we return an error without dropping the lock or freeing
the newly create mddev.
This patch fixes that.

Cc: stable@kernel.org
Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 12:27:21 +10:00
NeilBrown b8d966efd9 md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.
If we try to modify one of the md/ sysfs files
  suspend_lo or suspend_hi
when the array is not active, we dereference a NULL.
Protect against that.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 11:14:04 +10:00