Add __percpu sparse annotations to places which didn't make it in one
of the previous patches. All converions are trivial.
These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Revert commit d2bb7df8ca at Greg's request.
Author: Milan Broz <mbroz@redhat.com>
Date: Thu Dec 10 23:51:53 2009 +0000
dm: sysfs add empty release function to avoid debug warning
This patch just removes an unnecessary warning:
kobject: 'dm': does not have a release() function,
it is broken and must be fixed.
The kobject is embedded in mapped device struct, so
code does not need to release memory explicitly here.
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch fixes the problem that system may stall if target's ->map_rq
returns DM_MAPIO_REQUEUE in map_request().
E.g. stall happens on 1 CPU box when a dm-mpath device with queue_if_no_path
bounces between all-paths-down and paths-up on I/O load.
When target's ->map_rq returns DM_MAPIO_REQUEUE, map_request() requeues
the request and returns to dm_request_fn(). Then, dm_request_fn()
doesn't exit the I/O dispatching loop and continues processing
the requeued request again.
This map and requeue loop can be done with interrupt disabled,
so 1 CPU system can be stalled if this situation happens.
For example, commands below can stall my 1 CPU box within 1 minute or so:
# dmsetup table mp
mp: 0 2097152 multipath 1 queue_if_no_path 0 1 1 service-time 0 1 2 8:144 1 1
# while true; do dd if=/dev/mapper/mp of=/dev/null bs=1M count=100; done &
# while true; do \
> dmsetup message mp 0 "fail_path 8:144" \
> dmsetup suspend --noflush mp \
> dmsetup resume mp \
> dmsetup message mp 0 "reinstate_path 8:144" \
> done
To fix the problem above, this patch changes dm_request_fn() to exit
the I/O dispatching loop once if a request is requeued in map_request().
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
When suspending a failed mirror, bios are completed by mirror_end_io() and
__rh_lookup() in dm_rh_dec() returns NULL where a non-NULL return value is
required by design. Fix this by not changing the state of the recovery failed
region from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end().
Issue
On 2.6.33-rc1 kernel, I hit the bug when I suspended the failed
mirror by dmsetup command.
BUG: unable to handle kernel NULL pointer dereference at 00000020
IP: [<f94f38e2>] dm_rh_dec+0x35/0xa1 [dm_region_hash]
...
EIP: 0060:[<f94f38e2>] EFLAGS: 00010046 CPU: 0
EIP is at dm_rh_dec+0x35/0xa1 [dm_region_hash]
EAX: 00000286 EBX: 00000000 ECX: 00000286 EDX: 00000000
ESI: eff79eac EDI: eff79e80 EBP: f6915cd4 ESP: f6915cc4
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process dmsetup (pid: 2849, ti=f6914000 task=eff03e80 task.ti=f6914000)
...
Call Trace:
[<f9530af6>] ? mirror_end_io+0x53/0x1b1 [dm_mirror]
[<f9413104>] ? clone_endio+0x4d/0xa2 [dm_mod]
[<f9530aa3>] ? mirror_end_io+0x0/0x1b1 [dm_mirror]
[<f94130b7>] ? clone_endio+0x0/0xa2 [dm_mod]
[<c02d6bcb>] ? bio_endio+0x28/0x2b
[<f952f303>] ? hold_bio+0x2d/0x62 [dm_mirror]
[<f952f942>] ? mirror_presuspend+0xeb/0xf7 [dm_mirror]
[<c02aa3e2>] ? vmap_page_range+0xb/0xd
[<f9414c8d>] ? suspend_targets+0x2d/0x3b [dm_mod]
[<f9414ca9>] ? dm_table_presuspend_targets+0xe/0x10 [dm_mod]
[<f941456f>] ? dm_suspend+0x4d/0x150 [dm_mod]
[<f941767d>] ? dev_suspend+0x55/0x18a [dm_mod]
[<c0343762>] ? _copy_from_user+0x42/0x56
[<f9417fb0>] ? dm_ctl_ioctl+0x22c/0x281 [dm_mod]
[<f9417628>] ? dev_suspend+0x0/0x18a [dm_mod]
[<f9417d84>] ? dm_ctl_ioctl+0x0/0x281 [dm_mod]
[<c02c3c4b>] ? vfs_ioctl+0x22/0x85
[<c02c422c>] ? do_vfs_ioctl+0x4cb/0x516
[<c02c42b7>] ? sys_ioctl+0x40/0x5a
[<c0202858>] ? sysenter_do_call+0x12/0x28
Analysis
When recovery process of a region failed, dm_rh_recovery_end() function
changes the state of the region from RM_RH_RECOVERING to DM_RH_NOSYNC.
When recovery_complete() is executed between dm_rh_update_states() and
dm_writes() in do_mirror(), bios are processed with the region state,
DM_RH_NOSYNC. However, the region data is freed without checking its
pending count when dm_rh_update_states() is called next time.
When bios are finished by mirror_end_io(), __rh_lookup() in dm_rh_dec()
returns NULL even though a valid return value are expected.
Solution
Remove the state change of the recovery failed region from DM_RH_RECOVERING
to DM_RH_NOSYNC in dm_rh_recovery_end(). We can remove the state change
because:
- If the region data has been released by dm_rh_update_states(),
a new region data is created with the state of DM_RH_NOSYNC, and
bios are processed according to the DM_RH_NOSYNC state.
- If the region data has not been released by dm_rh_update_states(),
a state of the region is DM_RH_RECOVERING and bios are put in the
delayed_bio list.
The flag change from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end()
was added in the following commit:
dm raid1: handle resync failures
author Jonathan Brassow <jbrassow@redhat.com>
Thu, 12 Jul 2007 16:29:04 +0000 (17:29 +0100)
http://git.kernel.org/linus/f44db678edcc6f4c2779ac43f63f0b9dfa28b724
Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If the mirror log fails when the handle_errors option was not selected
and there is no remaining valid mirror leg, writes return success even
though they weren't actually written to any device. This patch
completes them with EIO instead.
This code path is taken:
do_writes:
bio_list_merge(&ms->failures, &sync);
do_failures:
if (!get_valid_mirror(ms)) (false)
else if (errors_handled(ms)) (false)
else bio_endio(bio, 0);
The logic in do_failures is based on presuming that the write was already
tried: if it succeeded at least on one leg (without handle_errors) it
is reported as success.
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=555197
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch fixes two bugs that revolve around the miscalculation and
misuse of the variable 'overhead_size'. 'overhead_size' is the size of
the various header structures used during communication.
The first bug is the use of 'sizeof' with the pointer of a structure
instead of the structure itself - resulting in the wrong size being
computed. This is then used in a check to see if the payload
(data_size) would be to large for the preallocated structure. Since the
bug produces a smaller value for the overhead, it was possible for the
structure to be breached. (Although the current users of the code do
not currently send enough data to trigger this bug.)
The second bug is that the 'overhead_size' value is used to compute how
much of the preallocated space should be cleared before populating it
with fresh data. This should have simply been 'sizeof(struct cn_msg)'
not overhead_size. The fact that 'overhead_size' was computed
incorrectly made this problem "less bad" - leaving only a pointer's
worth of space at the end uncleared. Thus, this bug was never producing
a bad result, but still needs to be fixed - especially now that the
value is computed correctly.
Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
chunk_io() declares its 'struct mdata_req' on the stack and then
initializes its 'struct work_struct' member. Annotate the
initialization of this workqueue with INIT_WORK_ON_STACK to suppress a
debugobjects warning seen when CONFIG_DEBUG_OBJECTS_WORK is enabled.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If a table containing zero as stripe count is passed into stripe_ctr
the code attempts to divide by zero.
This patch changes DM_TABLE_LOAD to return -EINVAL if the stripe count
is zero.
We now get the following error messages:
device-mapper: table: 253:0: striped: Invalid stripe count
device-mapper: ioctl: error adding target to table
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
======
This fix is related to
http://bugzilla.kernel.org/show_bug.cgi?id=15142
but does not address that exact issue.
======
sysfs does like attributes being removed while they are being accessed
(i.e. read or written) and waits for the access to complete.
As accessing some md attributes takes the same lock that is held while
removing those attributes a deadlock can occur.
This patch addresses 3 issues in md that could lead to this deadlock.
Two relate to calling flush_scheduled_work while the lock is held.
This is probably a bad idea in general and as we use schedule_work to
delete various sysfs objects it is particularly bad.
In one case flush_scheduled_work is called from md_alloc (called by
md_probe) called from do_md_run which holds the lock. This call is
only present to ensure that ->gendisk is set. However we can be sure
that gendisk is always set (though possibly we couldn't when that code
was originally written. This is because do_md_run is called in three
different contexts:
1/ from md_ioctl. This requires that md_open has succeeded, and it
fails if ->gendisk is not set.
2/ from writing a sysfs attribute. This can only happen if the
mddev has been registered in sysfs which happens in md_alloc
after ->gendisk has been set.
3/ from autorun_array which is only called by autorun_devices, which
checks for ->gendisk to be set before calling autorun_array.
So the call to md_probe in do_md_run can be removed, and the check on
->gendisk can also go.
In the other case flush_scheduled_work is being called in do_md_stop,
purportedly to wait for all md_delayed_delete calls (which delete the
component rdevs) to complete. However there really isn't any need to
wait for them - they have already been disconnected in all important
ways.
The third issue is that raid5->stop() removes some attribute names
while the lock is held. There is already some infrastructure in place
to delay attribute removal until after the lock is released (using
schedule_work). So extend that infrastructure to remove the
raid5_attrs_group.
This does not address all lockdep issues related to the sysfs
"s_active" lock. The rest can be address by splitting that lockdep
context between symlinks and non-symlinks which hopefully will happen.
Signed-off-by: NeilBrown <neilb@suse.de>
This code was written long ago when it was not possible to
reshape a degraded array. Now it is so the current level of
degraded-ness needs to be taken in to account. Also newly addded
devices should only reduce degradedness if they are deemed to be
in-sync.
In particular, if you convert a RAID5 to a RAID6, and increase the
number of devices at the same time, then the 5->6 conversion will
make the array degraded so the current code will produce a wrong
value for 'degraded' - "-1" to be precise.
If the reshape runs to completion end_reshape will calculate a correct
new value for 'degraded', but if a device fails during the reshape an
incorrect decision might be made based on the incorrect value of
"degraded".
This patch is suitable for 2.6.32-stable and if they are still open,
2.6.31-stable and 2.6.30-stable as well.
Cc: stable@kernel.org
Reported-by: Michael Evans <mjevans1983@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Make DM use bdev_stack_limits() function so that partition offsets get
taken into account when calculating alignment. Clarify stacking
warnings.
Also remove obsolete clearing of final alignment_offset and misalignment
flag.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair G. Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
If two arrays share a device, then they will not both resync at the
same time. One will wait for the other to complete.
While waiting, the MD_RECOVERY_INTR flag is not checked so a device
failure, which would make the resync pointless, does not cause the
resync to abort, so the failed device cannot be removed (as it cannot
be remove while a resync is happening).
So add a test for MD_RECOVERY_INTR.
Reported-by: Brett Russ <bruss@netezza.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Since commit dfc7064500,
->hot_remove_disks has not removed non-failed devices from
an array until recovery is no longer possible.
So the code in do_md_run to get around the fact that
md_check_recovery (which calls ->hot_remove_disks) would
remove partially-in-sync devices is no longer needed.
So remove it.
Signed-off-by: NeilBrown <neilb@suse.de>
By default md_do_sync() will perform recovery if no other actions are
specified. However, action_show() relies on MD_RECOVERY_RECOVER to be
set otherwise it returns 'idle'. So, add a missing set
MD_RECOVERY_RECOVER when starting recovery.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
The start_ro modules parameter can be used to force arrays to be
started in 'auto-readonly' in which they are read-only until the first
write. This ensures that no resync/recovery happens until something
else writes to the device. This is important for resume-from-disk
off an md array.
However if an array is started 'readonly' (by writing 'readonly' to
the 'array_state' sysfs attribute) we want it to be really 'readonly',
not 'auto-readonly'.
So strengthen the condition to only set auto-readonly if the
array is not already read-only.
Signed-off-by: NeilBrown <neilb@suse.de>
evms configures md arrays by:
open device
send ioctl
close device
for each different ioctl needed.
Since 2.6.29, the device can disappear after the 'close'
unless a significant configuration has happened to the device.
The change made by "SET_ARRAY_INFO" can too minor to stop the device
from disappearing, but important enough that losing the change is bad.
So: make sure SET_ARRAY_INFO sets mddev->ctime, and keep the device
active as long as ctime is non-zero (it gets zeroed with lots of other
things when the array is stopped).
This is suitable for -stable kernels since 2.6.29.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (80 commits)
dm snapshot: use merge origin if snapshot invalid
dm snapshot: report merge failure in status
dm snapshot: merge consecutive chunks together
dm snapshot: trigger exceptions in remaining snapshots during merge
dm snapshot: delay merging a chunk until writes to it complete
dm snapshot: queue writes to chunks being merged
dm snapshot: add merging
dm snapshot: permit only one merge at once
dm snapshot: support barriers in snapshot merge target
dm snapshot: avoid allocating exceptions in merge
dm snapshot: rework writing to origin
dm snapshot: add merge target
dm exception store: add merge specific methods
dm snapshot: create function for chunk_is_tracked wait
dm snapshot: make bio optional in __origin_write
dm mpath: reject messages when device is suspended
dm: export suspended state to targets
dm: rename dm_suspended to dm_suspended_md
dm: swap target postsuspend call and setting suspended flag
dm crypt: add plain64 iv
...
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.
It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
text data bss dec hex filename
64688 584 592 65864 10148 (TOTALS-BEFORE)
64641 584 592 65817 10119 (TOTALS-AFTER)
Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".
Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
drivers/leds/led-class.c
drivers/leds/ledtrig-timer.c
drivers/video/output.c
@@
expression str;
@@
( // ignore skip_spaces cases
while (*str && isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable external metadata arrays to manage rebuild checkpointing via a
md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset
Also update resync_start_store to allow 'none' to be written, for
consistency.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Other walks of this list are either under rcu_read_lock() or the list
mutation lock (mddev_lock()). This protects against the improbable case of a
disk being removed from the array at the start of md_do_sync().
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
As v1.x metadata can record that a member of the array is
not completely recovered, it make sense to record that a
spare has become a regular member of the array at the earliest
opportunity.
So remove the tests on "recovery_offset > 0" in super_1_sync
as they really aren't needed, and schedule a metadata update
immediately after adding spares to a degraded array.
This means that if a crash happens immediately after a recovery
starts, the new device will be included in the array and recovery will
continue from wherever it was up to. Previously this didn't happen
unless recovery was at least 1/16 of the way through.
Signed-off-by: NeilBrown <neilb@suse.de>
The RAID ioctls are only implemented in md.c, so the
handling for them should also be moved there from
fs/compat_ioctl.c.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Neil Brown <neilb@suse.de>
Cc: Andre Noll <maan@systemlinux.org>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Make it clear in the config message that MD_MULTIPATH is not under
active development.
Cc: Oren Held <orenhe@il.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
We've noticed severe lasting performance degradation of our raid
arrays when we have drives that yield large amounts of media errors.
The raid10 module will queue each failed read for retry, and also
will attempt call fix_read_error() to perform the read recovery.
Read recovery is performed while the array is frozen, so repeated
recovery attempts can degrade the performance of the array for
extended periods of time.
With this patch I propose adding a per md device max number of
corrected read attempts. Each rdev will maintain a count of
read correction attempts in the rdev->read_errors field (not
used currently for raid10). When we enter fix_read_error()
we'll check to see when the last read error occurred, and
divide the read error count by 2 for every hour since the
last read error. If at that point our read error count
exceeds the read error threshold, we'll fail the raid device.
In addition in this patch I add sysfs nodes (get/set) for
the per md max_read_errors attribute, the rdev->read_errors
attribute, and added some printk's to indicate when
fix_read_error fails to repair an rdev.
For testing I used debugfs->fail_make_request to inject
IO errors to the rdev while doing IO to the raid array.
Signed-off-by: Robert Becker <Rob.Becker@riverbed.com>
Signed-off-by: NeilBrown <neilb@suse.de>
When we get a read error on a device in a RAID10, and attempting to
repair the error fails, print more useful messages about why it
failed.
Signed-off-by: Robert Becker <Rob.Becker@riverbed.com>
Signed-off-by: NeilBrown <neilb@suse.de>
There is a sysfs file which allows bits in the write-intent
bitmap to be explicit set - indicating that the block is thought
to be 'dirty'.
When this happens we should really set recovery_cp backwards
to include the block to reflect this dirtiness.
In particular, a 'resync' process will refuse to start if
recovery_cp is beyond the end of the array, so this is needed
to allow a resync to be triggered.
Signed-off-by: NeilBrown <neilb@suse.de>
In this case, the metadata needs to not be in the same
sector as the bitmap.
md will not read/write any bitmap metadata. Config must be
done via sysfs and when a recovery makes the array non-degraded
again, writing 'true' to 'bitmap/can_clear' will allow bits in
the bitmap to be cleared again.
Signed-off-by: NeilBrown <neilb@suse.de>
Setting daemon_lastrun really has nothing to do with reading
the bitmap superblock, it just happens to be needed at the same time.
bitmap_read_sb is about to become options, so move that code out
to after the call to bitmap_read_sb.
Signed-off-by: NeilBrown <neilb@suse.de>
A new attribute directory 'bitmap' in 'md' is created which
contains files for configuring the bitmap.
'location' identifies where the bitmap is, either 'none',
or 'file' or 'sector offset from metadata'.
Writing 'location' can create or remove a bitmap.
Adding a 'file' bitmap this way is not yet supported.
'chunksize' and 'time_base' must be set before 'location'
can be set.
'chunksize' can be set before creating a bitmap, but is
currently always over-ridden by the bitmap superblock.
'time_base' and 'backlog' can be updated at any time.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Andre Noll <maan@systemlinux.org>
safe_delay_store can parse fixed point numbers (for fractions
of a second). We will want to do that for another sysfs
file soon, so factor out the code.
Signed-off-by: NeilBrown <neilb@suse.de>
For md arrays were metadata is managed externally, the kernel does not
know about a superblock so the superblock offset is 0.
If we want to have a write-intent-bitmap near the end of the
devices of such an array, we should support sector_t sized offset.
We need offset be possibly negative for when the bitmap is before
the metadata, so use loff_t instead.
Also add sanity check that bitmap does not overlap with data.
Signed-off-by: NeilBrown <neilb@suse.de>
As bitmap_create and bitmap_destroy already set thread->timeout
as appropriate, there is no need to do it in raid10_quiesce.
There is a possible need to wake the thread after the timeout
has been set low, but it is better to do that where the timeout
is actually set low, in bitmap_create.
Signed-off-by: NeilBrown <neilb@suse.de>
... and into bitmap_info. These are all configuration parameters
that need to be set before the bitmap is created.
Signed-off-by: NeilBrown <neilb@suse.de>
In preparation for making bitmap fields configurable via sysfs,
start tidying up by making a single structure to contain the
configuration fields.
Signed-off-by: NeilBrown <neilb@suse.de>
This will allow us to stop writeout to portions of the array
while they are resynced by someone else - e.g. another node in
a cluster.
Signed-off-by: NeilBrown <neilb@suse.de>
The post-barrier-flush is sent by md as soon as make_request on the
barrier write completes. For raid5, the data might not be in the
per-device queues yet. So for barrier requests, wait for any
pre-reading to be done so that the request will be in the per-device
queues.
We use the 'preread_active' count to check that nothing is still in
the preread phase, and delay the decrement of this count until after
write requests have been submitted to the underlying devices.
Signed-off-by: NeilBrown <neilb@suse.de>
Previously barriers were only supported on RAID1. This is because
other levels requires synchronisation across all devices and so needed
a different approach.
Here is that approach.
When a barrier arrives, we send a zero-length barrier to every active
device. When that completes - and if the original request was not
empty - we submit the barrier request itself (with the barrier flag
cleared) and then submit a fresh load of zero length barriers.
The barrier request itself is asynchronous, but any subsequent
request will block until the barrier completes.
The reason for clearing the barrier flag is that a barrier request is
allowed to fail. If we pass a non-empty barrier through a striping
raid level it is conceivable that part of it could succeed and part
could fail. That would be way too hard to deal with.
So if the first run of zero length barriers succeed, we assume all is
sufficiently well that we send the request and ignore errors in the
second run of barriers.
RAID5 needs extra care as write requests may not have been submitted
to the underlying devices yet. So we flush the stripe cache before
proceeding with the barrier.
Note that the second set of zero-length barriers are submitted
immediately after the original request is submitted. Thus when
a personality finds mddev->barrier to be set during make_request,
it should not return from make_request until the corresponding
per-device request(s) have been queued.
That will be done in later patches.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Andre Noll <maan@systemlinux.org>
If a resync/recovery/check/repair is interrupted for some reason, it
can be useful to know exactly where it got up to.
So in that case, do not clear curr_resync_completed.
Initialise it when starting a resync/recovery/... instead.
Signed-off-by: NeilBrown <neilb@suse.de>
When a 'check' or 'repair' finished we should clear resync_min
so that a future check/repair will cover the whole array (by default).
However if it is interrupted, we should update resync_min to
where we got up to, so that when the check/repair continues it
just does the remainder of the array.
Signed-off-by: NeilBrown <neilb@suse.de>
A write intent bitmap can be removed from an array while the
array is active.
When this happens, all IO is suspended and flushed before the
bitmap is removed.
However it is possible that bitmap_daemon_work is still running to
clear old bits from the bitmap. If it is, it can dereference the
bitmap after it has been freed.
So introduce a new mutex to protect bitmap_daemon_work and get it
before destroying a bitmap.
This is suitable for any current -stable kernel.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
If the snapshot we are merging became invalid (e.g. it ran out of
space) redirect all I/O directly to the origin device.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Set 'merge_failed' flag if a snapshot fails to merge. Update
snapshot_status() to report "Merge failed" if 'merge_failed' is set.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
s->store->type->prepare_merge returns the number of chunks that can be
copied linearly working backwards from the returned chunk number.
For example, if it returns 3 chunks with old_chunk == 10 and new_chunk
== 20, then chunk 20 can be copied to 10, chunk 19 to 9 and 18 to 8.
Until now kcopyd only copied one chunk at a time. This patch now copies
the full set at once.
Consequently, snapshot_merge_process() needs to delay the merging of all
chunks if any have writes in progress, not just the first chunk in the
region that is to be merged.
snapshot-merge's performance is now comparable to the original
snapshot-origin target.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
When there is one merging snapshot and other non-merging snapshots,
snapshot_merge_process() must make exceptions in the non-merging
snapshots.
Use a sequence count to resolve the race between I/O to chunks that are
about to be merged. The count increases each time an exception
reallocation finishes. Use wait_event() to wait until the count
changes.
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>
Track writes to chunks that are currently being merged and delay merging
a chunk until all writes to that chunk finish.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
While a set of chunks is being merged, any overlapping writes need to be
queued.
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>
Merging is started when origin is resumed and it is stopped when
origin is suspended or when the merging snapshot is destroyed or
errors are detected.
Merging is not yet interlocked with writes: this will be handled in
subsequent patches.
The code relies on callbacks from a private kcopyd thread.
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>
Merging more than one snapshot is not supported, so prevent
this happening.
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>
Sets num_flush_requests=2 to support flushing both the origin and cow
devices used by the snapshot-merge target.
Also, snapshot_ctr() now gets the origin device using FMODE_WRITE if the
target is snapshot-merge (which writes to the origin device).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The snapshot-merge target should not allocate new exceptions because the
intent is to merge all of its exceptions as quickly and safely as
possible.
This patch introduces the snapshot-merge mapping function and updates
__origin_write() so that it doesn't allocate exceptions on any snapshots
that are being merged.
If a write request to a merging snapshot device is to be dispatched
directly to the origin (because the chunk is not remapped or was already
merged), snapshot_merge_map() must make exceptions in other snapshots so
calls do_origin().
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>
To track the completion of exceptions relating to the same location on
the device, the current code selects one exception as primary_pe, links
the other exceptions to it and uses reference counting to wait until all
the reallocations are complete.
It is considered too complicated to extend this code to handle the new
snapshot-merge target, where sets of non-overlapping chunks would also
need to become linked.
Instead, a simpler (but less efficient) approach is taken. Bios are
linked to one exception. When it completes, bios are simply retried,
and if other related exceptions are still outstanding, they'll get
queued again to wait for another one.
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>
The snapshot-merge target allows a snapshot to be merged back into the
snapshot's origin device.
One anticipated use of snapshot merging is the rollback of filesystems
to back out problematic system upgrades.
This patch adds snapshot-merge target management to both
dm_snapshot_init() and dm_snapshot_exit(). As an initial place-holder,
snapshot-merge is identical to the snapshot target. Documentation is
provided.
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>
Add functions that decide how many consecutive chunks of snapshot to
merge back into the origin next and to update the metadata afterwards.
prepare_merge provides a pointer to the most recent still-to-be-merged
chunk and returns how many previous ones are consecutive and can be
processed together.
commit_merge removes the nr_merged most-recent chunks permanently from
the exception store. The number must not exceed that returned by
prepare_merge.
Introduce NUM_SNAPSHOT_HDR_CHUNKS to show where the snapshot header
chunk is accounted for.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move the __chunk_is_tracked() loop into a separate function as we will
also need to call it from the write path in the rare case of conflicting
writes to the same chunk.
Originally introduced in commit a8d41b59f3
("dm snapshot: fix race during exception creation").
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
To support the merging of snapshots back into their origin we need
to trigger exceptions in other snapshots not being merged without
any incoming bio on the origin device. The bio parameter to
__origin_write() becomes optional and the sector needs supplying
separately.
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>
This patch rejects messages that can generate I/O while the device
itself is suspended.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch adds the exported dm_suspended() function so that targets
can check whether or not they are suspended.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch renames dm_suspended() to dm_suspended_md() and
keeps it internal to dm.
No functional change.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch moves DMF_SUSPENDED flag set before postsuspend.
No one should care about the ordering, because the flag set and
the postsuspend are protected by a single lock, md->suspend_lock,
and all strict flag-checkers take the lock.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The default plain IV is 32-bit only.
This plain64 IV provides a compatible mode for encrypted devices bigger
than 4TB.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Permit in-use snapshot exception data to be 'handed over' from one
snapshot instance to another. This is a pre-requisite for patches
that allow the changes made in a snapshot device to be merged back into
its origin device and also allows device resizing.
The basic call sequence is:
dmsetup load new_snapshot (referencing the existing in-use cow device)
- the ctr code detects that the cow is already in use and allows the
two snapshot target instances to be linked together
dmsetup suspend original_snapshot
dmsetup resume new_snapshot
- the new_snapshot becomes live, and if anything now tries to access
the original one it will receive -EIO
dmsetup remove original_snapshot
(There can only be two snapshot targets referencing the same cow device
simultaneously.)
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
When swapping a new table into place, retain the old table until
its replacement is in place.
An old check for an empty table is removed because this is enforced
in populate_table().
__unbind() becomes redundant when followed by __bind().
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
When replacing a mapped device's table during a 'resume', delay the
destruction of the old table until the new one is successfully in place.
This will make it easier for a later patch to transfer internal state
information from the old table to the new one (something we do not currently
support) while giving us more options for reversion if a later part
of the operation fails.
Devices are always in the suspended state during dm_swap_table().
This patch reinforces the requirement that all I/O must have been
flushed from the table targets while in this state (including any in
workqueues). In the case of 'noflush' suspending, unprocessed
I/O should have been 'pushed back' to the dm core prior to this point,
for resubmission after the new table is in place.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add the flag DM_QUERY_INACTIVE_TABLE_FLAG to the ioctls to return
infomation about the loaded-but-not-yet-active table instead of the live
table. Prior to this patch it was impossible to obtain this information
until the device had been 'resumed'.
Userspace dmsetup and libdevmapper support the flag as of version 1.02.40.
e.g. dmsetup info --inactive vg1-lv1
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Accept empty barriers in dm-io.
dm-io will process empty write barrier requests just like the other
read/write requests.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Reject messages that can generate I/O while the device itself
is suspended.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add a mutex to allow possible creators of new work to synchronize with
flushing work queues.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Once we begin deleting a device, prevent any further messages being sent
to targets of its table (to avoid races).
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add dm_deleting_md to check whether or not a given mapped
device is currently being deleted.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch stops the remaining dm-mpath activity during the suspend
sequence by flushing workqueues in postsuspend function.
The current dm-mpath target may not be quiet even after suspend completes
because some workqueues (e.g. device_handler's work, event handling)
are not flushed during the suspend sequence, even though suspended
devices/targets are supposed to be quiet in this state.
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>
This patch adds barrier support for request-based dm.
CORE DESIGN
The design is basically same as bio-based dm, which emulates barrier
by mapping empty barrier bios before/after a barrier I/O.
But request-based dm has been using struct request_queue for I/O
queueing, so the block-layer's barrier mechanism can be used.
o Summary of the block-layer's behavior (which is depended by dm-core)
Request-based dm uses QUEUE_ORDERED_DRAIN_FLUSH ordered mode for
I/O barrier. It means that when an I/O requiring barrier is found
in the request_queue, the block-layer makes pre-flush request and
post-flush request just before and just after the I/O respectively.
After the ordered sequence starts, the block-layer waits for all
in-flight I/Os to complete, then gives drivers the pre-flush request,
the barrier I/O and the post-flush request one by one.
It means that the request_queue is stopped automatically by
the block-layer until drivers complete each sequence.
o dm-core
For the barrier I/O, treats it as a normal I/O, so no additional
code is needed.
For the pre/post-flush request, flushes caches by the followings:
1. Make the number of empty barrier requests required by target's
num_flush_requests, and map them (dm_rq_barrier()).
2. Waits for the mapped barriers to complete (dm_rq_barrier()).
If error has occurred, save the error value to md->barrier_error
(dm_end_request()).
(*) Basically, the first reported error is taken.
But -EOPNOTSUPP supersedes any error and DM_ENDIO_REQUEUE
follows.
3. Requeue the pre/post-flush request if the error value is
DM_ENDIO_REQUEUE. Otherwise, completes with the error value
(dm_rq_barrier_work()).
The pre/post-flush work above is done in the kernel thread (kdmflush)
context, since memory allocation which might sleep is needed in
dm_rq_barrier() but sleep is not allowed in dm_request_fn(), which is
an irq-disabled context.
Also, clones of the pre/post-flush request share an original, so
such clones can't be completed using the softirq context.
Instead, complete them in the context of underlying device drivers.
It should be safe since there is no I/O dispatching during
the completion of such clones.
For suspend, the workqueue of kdmflush needs to be flushed after
the request_queue has been stopped. Otherwise, the next flush work
can be kicked even after the suspend completes.
TARGET INTERFACE
No new interface is added.
Just use the existing num_flush_requests in struct target_type
as same as bio-based dm.
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>
This patch moves dm_end_request() to make the next patch more readable.
No functional change.
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>
This patch factors out the clone completion code, dm_done(),
from dm_softirq_done() in preparation for a subsequent patch.
No functional change.
dm_done() will be used in barrier completion, which can't use and
doesn't need softirq. The softirq_done callback needs to get a clone
from an original request but it can't in the case of barrier, where
an original request is shared by multiple clones. On the other hand,
the completion of barrier clones doesn't involve re-submitting requests,
which was the primary reason of the need for softirq.
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>
This patch changes the counter for the number of in_flight I/Os
to md->pending from q->in_flight in preparation for a later patch.
No functional change.
Request-based dm used q->in_flight to count the number of in-flight
clones assuming the counter is always incremented for an in-flight
original request and original:clone is 1:1 relationship.
However, it this no longer true for barrier requests.
So use md->pending to count the number of in-flight clones.
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>
The semantics of bio-based dm were changed recently in the case of
suspend with "--nolockfs" but without "--noflush".
Before 2.6.30, I/Os submitted before the suspend invocation were always
flushed. From 2.6.30 onwards, I/Os submitted before the suspend
invocation might not be flushed. (For details, see
http://marc.info/?t=123994433400003&r=1&w=2)
This patch brings the behaviour of request-based dm into line with
bio-based dm, simplifying the code and preparing for a subsequent patch
that will wait for all in_flight I/Os to complete without stopping
request_queue and use dm_wait_for_completion() for it.
This change in semantics simplifies the suspend code as follows:
o Suspend is implemented as stopping request_queue
in request-based dm, and all I/Os are queued in the request_queue
even after suspend is invoked.
o In the old semantics, we had to track whether I/Os were
queued before or after the suspend invocation, so a special
barrier-like request called 'suspend marker' was introduced.
o With the new semantics, we don't need to flush any I/O
so we can remove the marker and the code related to the marker
handling and I/O flushing.
After removing this codes, the suspend sequence is now:
1. Flush all I/Os by lock_fs() if needed.
2. Stop dispatching any I/O by stopping the request_queue.
3. Wait for all in-flight I/Os to be completed or requeued.
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>
This patch factors out the request cloning code in dm_prep_fn()
as clone_rq(). No functional change.
This patch is a preparation for a later patch in this series which needs to
make clones from an original barrier request.
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>
This patch adds the gfp_mask argument to alloc_rq_tio().
No functional change.
This patch is a preparation for a later patch in this series which needs to
allocate tio (for barrier I/O) with different allocation flag (GFP_NOIO) from
the one in the normal I/O code path.
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>
This patch changes the argument of map_request() to clone request
from original request. No functional change.
This patch is a preparation for PATCH 9, which needs to use
map_request() for clones sharing an original barrier request.
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>
This patch adds md_in_flight() to get the number of in_flight I/Os.
No functional change.
This patch is a preparation for a later patch in this series, which
changes I/O counter to md->pending from q->in_flight in request-based dm.
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>
dm-kcopyd: accept zero-size jobs
This patch changes dm-kcopyd so that it accepts zero-size jobs and completes
them immediatelly via its completion thread.
It is needed for multisnapshots snapshot resizing. When we are writing to
a chunk beyond origin end, no copying is done. To simplify the code, we submit
an empty request to kcopyd and let kcopyd complete it. If we didn't submit
a request to kcopyd and called the completion routine immediatelly, it would
violate the principle that completion is called only from one thread and
it would need additional locking.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Keep track of whether or not the device is suspended within the snapshot
target module, the same as we do in dm-raid1.
We will use this later to enforce the correct sequence of ioctls to
transfer the in-core exceptions from a snapshot target instance in
one table to a replacement one capable of merging them back
into the origin.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Store the reference to the snapshot cow device in the core snapshot
code instead of each exception store. It can be accessed through the
new function dm_snap_cow(). Exception stores should each now maintain a
reference to their parent snapshot struct.
This is cleaner and makes part of the forthcoming snapshot merge code simpler.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Add number of sectors used by metadata to the end of the snapshot's status
line.
Renamed dm_exception_store_type's 'fraction_full' to 'usage'. Renamed
arguments to be clearer about what is being returned. Also added
'metadata_sectors'.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Rename exception functions. Preparing to pull them out of
dm-snap.c for broader use.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Rename exception_table for broader use outside dm-snap.c
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The exception structure is not necessarily just a snapshot
element (especially after we pull it out of dm-snap.c).
Renaming appropriately.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Consolidate the insert_*exception functions. 'insert_completed_exception'
already contains all the logic to handle 'insert_exception' (via
check for a hash_shift of 0), so remove redundant function.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The origin needs to find minimum chunksize of all snapshots. This logic is
moved to a separate function because it will be used at another place in
the snapshot merge patches.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Removed unnecessary 'and' masking: The right shift discards the lower
bits so there is no need to clear them.
(A later patch needs this change to support a 32-bit chunk_mask.)
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Minor code touch-up. We don't need the 'else'.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
strlcpy() will always null terminate the string.
The code should already guarantee this as the last bytes are already
NULs and the string lengths were restricted before being stored in
hc. Removing the '-1' becomes necessary so strlcpy() doesn't
lose the last character of a maximum-length string.
- agk
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Hold all write bios when leg fails and errors are handled
When using a userspace daemon such as dmeventd to handle errors, we must
delay completing bios until it has done its job.
This patch prevents the following race:
- primary leg fails
- write "1" fail, the write is held, secondary leg is set default
- write "2" goes straight to the secondary leg
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Hold all write bios when errors are handled.
Previously the failures list was used only when handling errors with
a userspace daemon such as dmeventd. Now, it is always used for all bios.
The regions where some writes failed must be marked as nosync. This can only
be done in process context (i.e. in raid1 workqueue), not in the
write_callback function.
Previously the write would succeed if writing to at least one leg
succeeded. This is wrong because data from the failed leg may be
replicated to the correct leg. Now, if using a userspace daemon, the
write with some failures will be held until the daemon has done its job
and reconfigured the array. If not using a daemon, the write still
succeeds if at least one leg succeeds. This is bad, but it is consistent
with current behavior.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move bio completion out of dm_rh_mark_nosync in preparation for the
next patch.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move the logic to get a valid mirror leg into a function for re-use
in a later patch.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Use the hold framework in do_failures.
This patch doesn't change the bio processing logic, it just simplifies
failure handling and avoids periodically polling the failures list.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add framework to delay bios until a suspend and then resubmit them with
either DM_ENDIO_REQUEUE (if the suspend was noflush) or complete them
with -EIO. I/O barrier support will use this.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Report flush errors as 'F' instead of 'D' for log and mirror devices.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Implement flush callee. It uses dm_io to send zero-size barrier synchronously
and concurrently to all the mirror legs.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Call the flush callback from the log.
If flush failed, we have no alternative but to mark the whole log as dirty.
Also we set the variable flush_failed to prevent any bits ever being marked as
clean again.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Introduce a callback pointer from the log to dm-raid1 layer.
Before some region is set as "in-sync", we need to flush hardware cache on
all the disks. But the log module doesn't have access to the mirror_set
structure. So it will use this callback.
So far the callback is unused, it will be used in further patches.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Introduce "flush failed" variable. When a flush before clearing a bit
in the log fails, we don't know anything about which which regions are
in-sync and which not.
So we need to set all regions as not-in-sync and set the variable
"flush_failed" to prevent setting the in-sync bit in the future.
A target reload is the only way to get out of this situation.
The variable will be set in following patches.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Introduce flush_header and use it to flush the log device.
Note that we don't have to flush if all the regions transition
from "dirty" to "clean" state.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Split the variable "touched" into two, "touched_dirtied" and
"touched_cleaned", set when some region was dirtied or cleaned.
This will be used to optimize flushes.
After a transition from "dirty" to "clean" state we don't have flush hardware
cache on the log device. After a transition from "clean" to "dirty" the cache
must be flushed.
Before a transition from "clean" to "dirty" state we don't have to flush all
the raid legs. Before a transition from "dirty" to "clean" we must flush all
the legs to make sure that they are really in sync.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Flush support for dm-raid1.
When it receives an empty barrier, submit it to all the devices via dm-io.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove the hack where we allocate an extra bi_io_vec to store additional
private data. This hack prevents us from supporting barriers in
dm-raid1 without first making another little block layer change.
Instead of doing that, this patch eliminates the bi_io_vec abuse by
storing the region number directly in the low bits of bi_private.
We need to store two things for each bio, the pointer to the main io
structure and, if parallel writes were requested, an index indicating
which of these writes this bio belongs to. There can be at most
BITS_PER_LONG regions - 32 or 64.
The index (region number) was stored in the last (hidden) bio vector and
the pointer to struct io was stored in bi_private.
This patch now aligns "struct io" on BITS_PER_LONG bytes and stores the
region number in the low BITS_PER_LONG bits of bi_private.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Allocate "struct io" from a slab.
This patch changes dm-io, so that "struct io" is allocated from a slab cache.
It used to be allocated with kmalloc. Allocating from a slab will be needed
for the next patch, because it requires a special alignment of "struct io"
and kmalloc cannot meet this alignment.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The "wipe key" message is used to wipe the volume key from memory
temporarily, for example when suspending to RAM.
But the initialisation vector in ESSIV mode is calculated from the
hashed volume key, so the wipe message should wipe this IV key too and
reinitialise it when the volume key is reinstated.
This patch adds an IV wipe method called from a wipe message callback.
ESSIV is then reinitialised using the init function added by the
last patch.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch separates the construction of IV from its initialisation.
(For ESSIV it is a hash calculation based on volume key.)
Constructor code now preallocates hash tfm and salt array
and saves it in a private IV structure.
The next patch requires this to reinitialise the wiped IV
without reallocating memory when resuming a suspended device.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Use kzfree for salt deallocation because it is derived from the volume
key. Use a common error path in ESSIV constructor.
Required by a later patch which fixes the way key material is wiped
from memory.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Define private structures for IV so it's easy to add further attributes
in a following patch which fixes the way key material is wiped from
memory. Also move ESSIV destructor and remove unnecessary 'status'
operation.
There are no functional changes in this patch.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The "wipe key" message is used to wipe a volume key from memory
temporarily, for example when suspending to RAM.
There are two instances of the key in memory (inside crypto tfm)
but only one got wiped. This patch wipes them both.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Under some special conditions the snapshot hash_size is calculated as zero.
This patch instead sets a minimum value of 64, the same as for the
pending exception table.
rounddown_pow_of_two(0) is an undefined operation (it expands to shift
by -1). init_exception_table with an argument of 0 would fail with -ENOMEM.
The way to trigger the problem is to create a snapshot with a chunk size
that is larger than the origin device.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Take snapshot lock only for STATUSTYPE_INFO, not STATUSTYPE_TABLE.
Commit 4c6fff445d
(dm-snapshot-lock-snapshot-while-supplying-status.patch)
introduced this use of the lock, but userspace applications using
libdevmapper have been found to request STATUSTYPE_TABLE while the device
is suspended and the lock is already held, leading to deadlock. Since
the lock is not necessary in this case, don't try to take it.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch just removes an unnecessary warning:
kobject: 'dm': does not have a release() function,
it is broken and must be fixed.
The kobject is embedded in mapped device struct, so
code does not need to release memory explicitly here.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Error handling code following a kmalloc should free the allocated data.
Cc: stable@kernel.org
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Fix a reported deadlock if there are still unprocessed multipath events
on a device that is being removed.
_hash_lock is held during dev_remove while trying to send the
outstanding events. Sending the events requests the _hash_lock
again in dm_copy_name_and_uuid.
This patch introduces a separate lock around regions that modify the
link to the hash table (dm_set_mdptr) or the name or uuid so that
dm_copy_name_and_uuid no longer needs _hash_lock.
Additionally, dm_copy_name_and_uuid can only be called if md exists
so we can drop the dm_get() and dm_put() which can lead to a BUG()
while md is being freed.
The deadlock:
#0 [ffff8106298dfb48] schedule at ffffffff80063035
#1 [ffff8106298dfc20] __down_read at ffffffff8006475d
#2 [ffff8106298dfc60] dm_copy_name_and_uuid at ffffffff8824f740
#3 [ffff8106298dfc90] dm_send_uevents at ffffffff88252685
#4 [ffff8106298dfcd0] event_callback at ffffffff8824c678
#5 [ffff8106298dfd00] dm_table_event at ffffffff8824dd01
#6 [ffff8106298dfd10] __hash_remove at ffffffff882507ad
#7 [ffff8106298dfd30] dev_remove at ffffffff88250865
#8 [ffff8106298dfd60] ctl_ioctl at ffffffff88250d80
#9 [ffff8106298dfee0] do_ioctl at ffffffff800418c4
#10 [ffff8106298dff00] vfs_ioctl at ffffffff8002fab9
#11 [ffff8106298dff40] sys_ioctl at ffffffff8004bdaf
#12 [ffff8106298dff80] tracesys at ffffffff8005d28d (via system_call)
Cc: stable@kernel.org
Reported-by: guy keren <choo@actcom.co.il>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (222 commits)
[SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP
[SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport class
[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED
[SCSI] zfcp: Update FSF error reporting
[SCSI] zfcp: Improve ELS ADISC handling
[SCSI] zfcp: Simplify handling of ct and els requests
[SCSI] zfcp: Remove ZFCP_DID_MASK
[SCSI] zfcp: Move WKA port to zfcp FC code
[SCSI] zfcp: Use common code definitions for FC CT structs
[SCSI] zfcp: Use common code definitions for FC ELS structs
[SCSI] zfcp: Update FCP protocol related code
[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport
[SCSI] zfcp: Assign scheduled work to driver queue
[SCSI] zfcp: Remove STATUS_COMMON_REMOVE flag as it is not required anymore
[SCSI] zfcp: Implement module unloading
[SCSI] zfcp: Merge trace code for fsf requests in one function
[SCSI] zfcp: Access ports and units with container_of in sysfs code
[SCSI] zfcp: Remove suspend callback
[SCSI] zfcp: Remove global config_mutex
[SCSI] zfcp: Replace local reference counting with common kref
...
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6: (43 commits)
security/tomoyo: Remove now unnecessary handling of security_sysctl.
security/tomoyo: Add a special case to handle accesses through the internal proc mount.
sysctl: Drop & in front of every proc_handler.
sysctl: Remove CTL_NONE and CTL_UNNUMBERED
sysctl: kill dead ctl_handler definitions.
sysctl: Remove the last of the generic binary sysctl support
sysctl net: Remove unused binary sysctl code
sysctl security/tomoyo: Don't look at ctl_name
sysctl arm: Remove binary sysctl support
sysctl x86: Remove dead binary sysctl support
sysctl sh: Remove dead binary sysctl support
sysctl powerpc: Remove dead binary sysctl support
sysctl ia64: Remove dead binary sysctl support
sysctl s390: Remove dead sysctl binary support
sysctl frv: Remove dead binary sysctl support
sysctl mips/lasat: Remove dead binary sysctl support
sysctl drivers: Remove dead binary sysctl support
sysctl crypto: Remove dead binary sysctl support
sysctl security/keys: Remove dead binary sysctl support
sysctl kernel: Remove binary sysctl logic
...
Make scsi_dh_activate() function asynchronous, by taking in two additional
parameters, one is the callback function and the other is the data to call
the callback function with.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
commit 4706b349f was a forward port of a fix that was needed
for SLES10. But in fact it is not needed in mainline because
the earlier commit dd00a99e7a fixes the same problem in a
better way.
Further, this commit introduces a bug in the way it interacts with
the automatic read-error-correction. If, after a read error is
successfully corrected, the same disk is chosen to re-read - the
re-read won't be attempted but an error will be returned instead.
After reverting that commit, there is the possibility that a
read error on a read-only array (where read errors cannot
be corrected as that requires a write) will repeatedly read the same
device and continue to get an error.
So in the "Array is readonly" case, fail the drive immediately on
a read error.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
For consistency drop & in front of every proc_handler. Explicity
taking the address is unnecessary and it prevents optimizations
like stubbing the proc_handlers to NULL.
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Resolve the conflict between v2.6.32-rc7 where dn_def_dev_handler
gets a small bug fix and the sysctl tree where I am removing all
sysctl strategy routines.
Normally is it not safe to allow a raid5 that is both dirty and
degraded to be assembled without explicit request from that admin, as
it can cause hidden data corruption.
This is because 'dirty' means that the parity cannot be trusted, and
'degraded' means that the parity needs to be used.
However, if the device that is missing contains only parity, then
there is no issue and assembly can continue.
This particularly applies when a RAID5 is being converted to a RAID6
and there is an unclean shutdown while the conversion is happening.
So check for whether the degraded space only contains parity, and
in that case, allow the assembly.
Signed-off-by: NeilBrown <neilb@suse.de>
When a reshape finds that it can add spare devices into the array,
those devices might already be 'in_sync' if they are beyond the old
size of the array, or they might not if they are within the array.
The first case happens when we change an N-drive RAID5 to an
N+1-drive RAID5.
The second happens when we convert an N-drive RAID5 to an
N+1-drive RAID6.
So set the flag more carefully.
Also, ->recovery_offset is only meaningful when the flag is clear,
so only set it in that case.
This change needs the preceding two to ensure that the non-in_sync
device doesn't get evicted from the array when it is stopped, in the
case where v0.90 metadata is used.
Signed-off-by: NeilBrown <neilb@suse.de>
This is a combination that didn't really make sense before.
However when a reshape is converting e.g. raid5 -> raid6, the extra
device is not fully in-sync, but is certainly active and contains
important data.
So allow that start to be meaningful and in particular get
the 'recovery_offset' value (which is needed for any non-in-sync
active device) from the reshape_position.
Signed-off-by: NeilBrown <neilb@suse.de>
Now that sys_sysctl is a wrapper around /proc/sys all of
the binary sysctl support elsewhere in the tree is
dead code.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Neil Brown <neilb@suse.de>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Acked-by: Clemens Ladisch <clemens@ladisch.de> for drivers/char/hpet.c
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Each device has its own 'recovery_offset' showing how far
recovery has progressed on the device.
As the only real significance of this is that fact that it can
be stored in the metadata and recovered at restart, and as
only 1.x metadata can do this, we were only updating
'recovery_offset' to 'curr_resync_completed' when updating
v1.x metadata.
But this is wrong, and we will shortly make limited use of this
field in v0.90 metadata.
So move the update into common code.
Signed-off-by: NeilBrown <neilb@suse.de>
something-bility is spelled as something-blity
so a grep for 'blit' would find these lines
this is so trivial that I didn't split it by subsystem / copy
additional maintainers - all changes are to comments
The only purpose is to get fewer false positives when grepping
around the kernel sources.
Signed-off-by: Dirk Hohndel <hohndel@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This value is visible through sysfs and is used by mdadm
when it manages a reshape (backing up data that is about to be
rearranged). So it is important that it is always correct.
Current it does not get updated properly when a reshape
starts which can cause problems when assembling an array
that is in the middle of being reshaped.
This is suitable for 2.6.31.y stable kernels.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
If a 'sync_max' has been set (via sysfs), it is wrong to clear it
until a resync (or reshape or recovery ...) actually reached that
point.
So if a resync is interrupted (e.g. by device failure),
leave 'resync_max' unchanged.
This is particularly important for 'reshape' operations that do not
change the size of the array. For such operations mdadm needs to
monitor the reshape taking rolling backups of the section being
reshaped. If resync_max gets cleared, the reshape can get ahead of
mdadm and then the backups that mdadm creates are useless.
This is suitable for 2.6.31.y stable kernels.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
* 'for-linus' of git://neil.brown.name/md:
async_tx: fix asynchronous raid6 recovery for ddf layouts
async_pq: rename scribble page
async_pq: kill a stray dma_map() call and other cleanups
md/raid6: kill a gcc-4.0.1 'uninitialized variable' warning
raid6/async_tx: handle holes in block list in async_syndrome_val
md/async: don't pass a memory pointer as a page pointer.
md: Fix handling of raid5 array which is being reshaped to fewer devices.
md: fix problems with RAID6 calculations for DDF.
md/raid456: downlevel multicore operations to raid_run_ops
md: drivers/md/unroll.pl replaced with awk analog
md: remove clumsy usage of do_sync_mapping_range from bitmap code
md: raid1/raid10: handle allocation errors during array setup.
md/raid5: initialize conf->device_lock earlier
md/raid1/raid10: add a cond_resched
Revert "md: do not progress the resync process if the stripe was blocked"
Allow the snapshot chunk size to be smaller than the page size
The code is now capable of handling this due to some previous
fixes and enhancements.
As the page size varies between computers, prior to this patch,
the chunk size of a snapshot dictated which machines could read it:
Snapshots created on one machine might not be readable on another.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Use unsigned integer chunk size.
Maximum chunk size is 512kB, there won't ever be need to use 4GB chunk size,
so the number can be 32-bit. This fixes compiler failure on 32-bit systems
with large block devices.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch locks the snapshot when returning status. It fixes a race
when it could return an invalid number of free chunks if someone
was simultaneously modifying it.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Properly close the device if failing because of an invalid chunk size.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If we are creating snapshot with memory-stored exception store, fail if
the user didn't specify chunk size. Zero chunk size would probably crash
a lot of places in the rest of snapshot code.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Multiple instances of dec_pending() can run concurrently so a lock is
needed when it saves the first error code.
I have never experienced actual problem without locking and just found
this during code inspection while implementing the barrier support
patch for request-based dm.
This patch adds the locking.
I've done compile, boot and basic I/O testings.
Cc: stable@kernel.org
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>
Add missing del_gendisk() to error path when creation of workqueue fails.
Otherwice there is a resource leak and following warning is shown:
WARNING: at fs/sysfs/dir.c:487 sysfs_add_one+0xc5/0x160()
sysfs: cannot create duplicate filename '/devices/virtual/block/dm-0'
Cc: stable@kernel.org
Signed-off-by: Zdenek Kabelac <zkabelac@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
mips:
drivers/md/dm-log-userspace-base.c: In function `userspace_ctr':
drivers/md/dm-log-userspace-base.c:159: warning: cast from pointer to integer of different size
Cc: stable@kernel.org
Cc: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
While initializing the snapshot module, if we fail to register
the snapshot target then we must back-out the exception store
module initialization.
Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Avoid a race causing corruption when snapshots of the same origin have
different chunk sizes by sorting the internal list of snapshots by chunk
size, largest first.
https://bugzilla.redhat.com/show_bug.cgi?id=182659
For example, let's have two snapshots with different chunk sizes. The
first snapshot (1) has small chunk size and the second snapshot (2) has
large chunk size. Let's have chunks A, B, C in these snapshots:
snapshot1: ====A==== ====B====
snapshot2: ==========C==========
(Chunk size is a power of 2. Chunks are aligned.)
A write to the origin at a position within A and C comes along. It
triggers reallocation of A, then reallocation of C and links them
together using A as the 'primary' exception.
Then another write to the origin comes along at a position within B and
C. It creates pending exception for B. C already has a reallocation in
progress and it already has a primary exception (A), so nothing is done
to it: B and C are not linked.
If the reallocation of B finishes before the reallocation of C, because
there is no link with the pending exception for C it does not know to
wait for it and, the second write is dispatched to the origin and causes
data corruption in the chunk C in snapshot2.
To avoid this situation, we maintain snapshots sorted in descending
order of chunk size. This leads to a guaranteed ordering on the links
between the pending exceptions and avoids the problem explained above -
both A and B now get linked to C.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
md/raid6 passes a list of 'struct page *' to the async_tx routines,
which then either DMA map them for offload, or take the page_address
for CPU based calculations.
For RAID6 we sometime leave 'blanks' in the list of pages.
For CPU based calcs, we want to treat theses as a page of zeros.
For offloaded calculations, we simply don't pass a page to the
hardware.
Currently the 'blanks' are encoded as a pointer to
raid6_empty_zero_page. This is a 4096 byte memory region, not a
'struct page'. This is mostly handled correctly but is rather ugly.
So change the code to pass and expect a NULL pointer for the blanks.
When taking page_address of a page, we need to check for a NULL and
in that case use raid6_empty_zero_page.
Signed-off-by: NeilBrown <neilb@suse.de>
When a raid5 (or raid6) array is being reshaped to have fewer devices,
conf->raid_disks is the latter and hence smaller number of devices.
However sometimes we want to use a number which is the total number of
currently required devices - the larger of the 'old' and 'new' sizes.
Before we implemented reducing the number of devices, this was always
'new' i.e. ->raid_disks.
Now we need max(raid_disks, previous_raid_disks) in those places.
This particularly affects assembling an array that was shutdown while
in the middle of a reshape to fewer devices.
md.c needs a similar fix when interpreting the md metadata.
Signed-off-by: NeilBrown <neilb@suse.de>
The percpu conversion allowed a straightforward handoff of stripe
processing to the async subsytem that initially showed some modest gains
(+4%). However, this model is too simplistic and leads to stripes
bouncing between raid5d and the async thread pool for every invocation
of handle_stripe(). As reported by Holger this can fall into a
pathological situation severely impacting throughput (6x performance
loss).
By downleveling the parallelism to raid_run_ops the pathological
stripe_head bouncing is eliminated. This version still exhibits an
average 11% throughput loss for:
mdadm --create /dev/md0 /dev/sd[b-q] -n 16 -l 6
echo 1024 > /sys/block/md0/md/stripe_cache_size
dd if=/dev/zero of=/dev/md0 bs=1024k count=2048
...but the results are at least stable and can be used as a base for
further multicore experimentation.
Reported-by: Holger Kiehl <Holger.Kiehl@dwd.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
drivers/md/unroll.pl replaced by awk script to drop build-time
dependency on perl
Signed-off-by: Vladimir Dronnikov <dronnikov@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
and replace with vfs_fsync which is much neater (but wasn't exported,
or even in existence at the time the code was written).
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Both raid1 and raid10 create a mempool during startup.
If the 'alloc' function for this mempool fails, unplug_slaves
is called.
If that happens when the pool is being initialised, unplug_slaves
will try to use the 'conf' structure that isn't filled in yet, and
badness will happen.
So ensure that unplug_slaves doesn't get called unless we know
that the conf structure if fully initialised.
Signed-off-by: NeilBrown <neilb@suse.de>
Deallocating a raid5_conf_t structure requires taking 'device_lock'.
Ensure it is initialized before it is used, i.e. initialize the lock
before attempting any further initializations that might fail.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
During 'check' of a raid1 or raid10 it is possible for the management
thread to spend a lot of time running 'memcmp' on blocks from
different devices, so make sure the thread has a chance to schedule.
raid5d already has a cond_resched (in process_stripe).
Reported-By: Lee Howard <faxguy@howardsilvan.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This reverts commit df10cfbc4d.
This patch was based on a misunderstanding and risks introducing a busy-wait loop.
So revert it.
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Commit a9327cac44 added seperate read
and write statistics of in_flight requests. And exported the number
of read and write requests in progress seperately through sysfs.
But Corrado Zoccolo <czoccolo@gmail.com> reported getting strange
output from "iostat -kx 2". Global values for service time and
utilization were garbage. For interval values, utilization was always
100%, and service time is higher than normal.
So this was reverted by commit 0f78ab9899
The problem was in part_round_stats_single(), I missed the following:
if (now == part->stamp)
return;
- if (part->in_flight) {
+ if (part_in_flight(part)) {
__part_stat_add(cpu, part, time_in_queue,
part_in_flight(part) * (now - part->stamp));
__part_stat_add(cpu, part, io_ticks, (now - part->stamp));
With this chunk included, the reported regression gets fixed.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
--
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (41 commits)
Revert "Seperate read and write statistics of in_flight requests"
cfq-iosched: don't delay async queue if it hasn't dispatched at all
block: Topology ioctls
cfq-iosched: use assigned slice sync value, not default
cfq-iosched: rename 'desktop' sysfs entry to 'low_latency'
cfq-iosched: implement slower async initiate and queue ramp up
cfq-iosched: delay async IO dispatch, if sync IO was just done
cfq-iosched: add a knob for desktop interactiveness
Add a tracepoint for block request remapping
block: allow large discard requests
block: use normal I/O path for discard requests
swapfile: avoid NULL pointer dereference in swapon when s_bdev is NULL
fs/bio.c: move EXPORT* macros to line after function
Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
cciss: fix build when !PROC_FS
block: Do not clamp max_hw_sectors for stacking devices
block: Set max_sectors correctly for stacking devices
cciss: cciss_host_attr_groups should be const
cciss: Dynamically allocate the drive_info_struct for each logical drive.
cciss: Add usage_count attribute to each logical drive in /sys
...
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Recently Jens has changed bio_rw_flagged() logic by following
commit 1f98a13f62. Now it returns
bool instead of int. This broke raid1/raid10 RW bits manipulation logic.
One of visible result is BUG_ON triggering due to empty barrier
here scsi_lib.c:1108 scsi_setup_fs_cmnd()
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Recent commit bbba809e96
replaced mempool_create_kzalloc_pool with mempool_create_kmalloc_pool
plus a memset.
This memset is not needed (and we didn't need kzalloc in the first
place).
Ever field of the allocated structure (struct multipath_bh) is
initialised immediately except retry_list, and memset does not
initial a list_head anyway.
To remove the memset.
Signed-off-by: NeilBrown <neilb@suse.de>
The management thread for raid4,5,6 arrays are all called
mdX_raid5, independent of the actual raid level, which is wrong and
can be confusion.
So change md_register_thread to use the name from the personality
unless no alternate name (like 'resync' or 'reshape') is given.
This is simpler and more correct.
Cc: Jinzc <zhenchengjin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Rename some variable and remove some duplicate definitions
to avoid there warnings. None of them are actual errors.
Signed-off-by: NeilBrown <neilb@suse.de>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
trivial: fix typo in aic7xxx comment
trivial: fix comment typo in drivers/ata/pata_hpt37x.c
trivial: typo in kernel-parameters.txt
trivial: fix typo in tracing documentation
trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c
trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c
trivial: remove unnecessary semicolons
trivial: Fix duplicated word "options" in comment
trivial: kbuild: remove extraneous blank line after declaration of usage()
trivial: improve help text for mm debug config options
trivial: doc: hpfall: accept disk device to unload as argument
trivial: doc: hpfall: reduce risk that hpfall can do harm
trivial: SubmittingPatches: Fix reference to renumbered step
trivial: fix typos "man[ae]g?ment" -> "management"
trivial: media/video/cx88: add __init/__exit macros to cx88 drivers
trivial: fix typo in CONFIG_DEBUG_FS in gcov doc
trivial: fix missing printk space in amd_k7_smp_check
trivial: fix typo s/ketymap/keymap/ in comment
trivial: fix typo "to to" in multiple files
trivial: fix typos in comments s/DGBU/DBGU/
...
The kzalloc mempool does not re-zero items that have been used and then
returned to the pool. Manually zero the allocated multipath_bh instead.
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.
This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Neil says:
"It is correct as it stands, but the fact that every branch in
the 'if' part ends with a 'return' isn't immediately obvious,
so it is clearer if we are explicit about the if / then / else
structure."
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
As pointed out by Neil it should be possible to build a driver with all
BUG_ON statements deleted. It's bad form to have a BUG_ON with a side
effect.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* '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
...
* 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.
...
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>
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>
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>
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>
Some engines optimize operation by reading ahead in the descriptor chain
such that descriptor2 may start execution before descriptor1 completes.
If descriptor2 depends on the result from descriptor1 then a fence is
required (on descriptor2) to disable this optimization. The async_tx
api could implicitly identify dependencies via the 'depend_tx'
parameter, but that would constrain cases where the dependency chain
only specifies a completion order rather than a data dependency. So,
provide an ASYNC_TX_FENCE to explicitly identify data dependencies.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
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>
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>
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>
Tejun Heo