15 Jan, 2012
1 commit
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A logical volume can map to just part of underlying physical volume.
In this case, it must be treated like a partition.Based on a patch from Alasdair G Kergon.
Cc: Alasdair G Kergon
Cc: dm-devel@redhat.com
Signed-off-by: Paolo Bonzini
Signed-off-by: Linus Torvalds
02 Aug, 2011
2 commits
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Move multipath target argument parsing code into dm-table so other
targets can share it.Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon -
Avoid dereferencing a NULL pointer if the number of feature arguments
supplied is fewer than indicated.Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
Cc: stable@kernel.org
27 Jul, 2011
1 commit
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This allows us to move duplicated code in
(atomic_inc_not_zero() for now) toSigned-off-by: Arun Sharma
Reviewed-by: Eric Dumazet
Cc: Ingo Molnar
Cc: David Miller
Cc: Eric Dumazet
Acked-by: Mike Frysinger
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 May, 2011
1 commit
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Integrity errors need to be passed to the owner of the integrity
metadata for processing. Consequently EILSEQ should be passed up the
stack.Cc: stable@kernel.org
Signed-off-by: Martin K. Petersen
Acked-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
24 Mar, 2011
2 commits
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This patch adjusts the multipath target to allow a table with both 0
priority groups and 0 for the initial priority group number.If any mpath device is held open when all paths in the last priority
group have failed, userspace multipathd will attempt to reload the
associated DM table to reflect the fact that the device no longer has
any priority groups. But the reload attempt always failed because the
multipath target did not allow 0 priority groups.All multipath target messages related to priority group (enable_group,
disable_group, switch_group) will handle a priority group of 0 (will
cause error).When reloading a multipath table with 0 priority groups, userspace
multipathd must be updated to specify an initial priority group number
of 0 (rather than 1).Signed-off-by: Mike Snitzer
Cc: Babu Moger
Acked-by: Hannes Reinecke
Signed-off-by: Alasdair G Kergon -
Fail the reinstate_path and fail_path message ioctl if the specified
path is not valid.The message ioctl would succeed for the 'reinistate_path' and
'fail_path' messages even if action was not taken because the
specified device was not a valid path of the multipath device.Before, when /dev/vdb is not a path of mpathb:
$ dmsetup message mpathb 0 reinstate_path /dev/vdb
$ echo $?
0After:
$ dmsetup message mpathb 0 reinstate_path /dev/vdb
device-mapper: message ioctl failed: Invalid argument
Command failed
$ echo $?
1Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
13 Feb, 2011
1 commit
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DM now has more information about the nature of the underlying storage
failure. Path failure is avoided if a request failed due to a target
error. Instead the target error is immediately passed up the stack.Discard requests that fail due to non-target errors may now be retried.
Errors restricted to the path will be retried or returned if no
paths are available, irregarding the no_path_retry setting.Signed-off-by: Mike Snitzer
Signed-off-by: Hannes Reinecke
Acked-by: Alasdair G Kergon
Signed-off-by: James Bottomley
14 Jan, 2011
4 commits
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This patch adds a user-configurable 'pg_init_delay_msecs' feature. Use
this feature to specify the number of milliseconds to delay before
retrying scsi_dh_activate, when SCSI_DH_RETRY is returned.SCSI Device Handlers return SCSI_DH_IMM_RETRY if we could retry
activation immediately and SCSI_DH_RETRY in cases where it is better to
retry after some delay.Currently we immediately retry scsi_dh_activate irrespective of
SCSI_DH_IMM_RETRY and SCSI_DH_RETRY.The 'pg_init_delay_msecs' feature may be provided during table create or
load, e.g.:
dmsetup create --table "0 20971520 multipath 3 queue_if_no_path \
pg_init_delay_msecs 2500 ..." mpathaThe default for 'pg_init_delay_msecs' is 2000 milliseconds.
Maximum configurable delay is 60000 milliseconds. Specifying a
'pg_init_delay_msecs' of 0 will cause immediate retry.Signed-off-by: Nikanth Karthikesan
Signed-off-by: Chandra Seetharaman
Acked-by: Mike Christie
Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon -
Convert all create[_singlethread]_work() users to the new
alloc[_ordered]_workqueue(). This conversion is mechanical and
doesn't introduce any behavior change.Signed-off-by: Tejun Heo
Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon -
flush_scheduled_work() is being deprecated. Flush the used work
directly instead. In all dm targets, the only work which uses
system_wq is ->trigger_event.Signed-off-by: Tejun Heo
Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon -
Revert commit 224cb3e981f1b2f9f93dbd49eaef505d17d894c2
dm: Call blk_abort_queue on failed pathsMultipath began to use blk_abort_queue() to allow for
lower latency path deactivation. This was found to
cause list corruption:the cmd gets blk_abort_queued/timedout run on it and the scsi eh
somehow is able to complete and run scsi_queue_insert while
scsi_request_fn is still trying to process the request.https://www.redhat.com/archives/dm-devel/2010-November/msg00085.html
Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
Cc: Mike Anderson
Cc: Mike Christie
Cc: stable@kernel.org
12 Aug, 2010
2 commits
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Enable discard support in the DM multipath target.
This discard support depends on a few discard-specific fixes to the
block layer's request stacking driver methods.Discard requests are optional so don't allow a failed discard to trigger
path failures. If there is a real problem with a given path the
barriers associated with the discard (either before or after the
discard) will cause path failure. That said, unconditionally passing
discard failures up the stack is not ideal. This must be fixed once DM
has more information about the nature of the underlying storage failure.Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
Cc: Kiyoshi Ueda -
multipath_ctr() forgets to return an error after detecting
missing path parameters. Fix this.Signed-off-by: Patrick LoPresti
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon
06 Mar, 2010
7 commits
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Remove unused parameters(start and len) of dm_get_device()
and fix the callers.Signed-off-by: Nikanth Karthikesan
Signed-off-by: Alasdair G Kergon -
This patch pulls the pg_init path activation code out of
process_queued_ios() into a new function.No functional change.
Signed-off-by: Kiyoshi Ueda
Signed-off-by: Jun'ichi Nomura
Signed-off-by: Alasdair G Kergon -
When suspending the device we must wait for all I/O to complete, but
pg-init may be still in progress even after flushing the workqueue
for kmpath_handlerd in multipath_postsuspend.This patch waits for pg-init completion correctly in
multipath_postsuspend().Signed-off-by: Kiyoshi Ueda
Signed-off-by: Jun'ichi Nomura
Signed-off-by: Alasdair G Kergon -
m->queue_io is set to block processing I/Os, and it needs to be kept
while pg-init, which issues multiple path activations, is in progress.
But m->queue is cleared when a path activation completes without error
in pg_init_done(), even while other path activations are in progress.
That may cause undesired -EIO on paths which are not complete activation.This patch fixes that by not clearing m->queue_io until all path
activations complete.(Before the hardware handlers were moved into the SCSI layer, pg_init
only used one path.)Signed-off-by: Kiyoshi Ueda
Signed-off-by: Jun'ichi Nomura
Signed-off-by: Alasdair G Kergon -
'suspended' flag in struct multipath was introduced to check whether
the multipath target is in suspended state, but the same check is
done through dm_suspended() now, so remove the flag and related code.Signed-off-by: Kiyoshi Ueda
Signed-off-by: Jun'ichi Nomura
Cc: Mike Anderson
Signed-off-by: Alasdair G Kergon -
This patch adds two minor fixes while processing device mapper path activation.
Skip failed paths while calling activate_path. If the path is already failed
then activate_path will fail for sure. We don't have to call in that case. In
some case this might cause prolonged retries unnecessarily.Change the misleading message if the path being activated fails with SCSI_DH_NOSYS.
Signed-off-by: Babu Moger
Signed-off-by: Alasdair G Kergon -
This patch removes some unnecessary argument casting. There is no
functional change with this patch.Passes 'struct pgpath' through to pg_init_done() instead of the enclosed
'struct dm_path'.Tested the changes with LSI storage..
CC: Chandra Seetharaman
Signed-off-by: Babu Moger
Acked-by: Kiyoshi Ueda
Signed-off-by: Alasdair G Kergon
11 Dec, 2009
4 commits
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This patch rejects messages that can generate I/O while the device
itself is suspended.Signed-off-by: Kiyoshi Ueda
Cc: Mike Anderson
Signed-off-by: Jun'ichi Nomura
Signed-off-by: Alasdair G Kergon -
Reject messages that can generate I/O while the device itself
is suspended.Signed-off-by: Mike Anderson
Acked-by: Kiyoshi Ueda
Signed-off-by: Alasdair G Kergon -
Add a mutex to allow possible creators of new work to synchronize with
flushing work queues.Signed-off-by: Mike Anderson
Acked-by: Kiyoshi Ueda
Signed-off-by: Alasdair G Kergon -
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
Signed-off-by: Jun'ichi Nomura
Signed-off-by: Alasdair G Kergon
05 Dec, 2009
1 commit
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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
Signed-off-by: James Bottomley
23 Aug, 2009
1 commit
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Use scsi_dh_set_params() set parameters provided. Save the parameters in
parse_hw_handler() and use it in parse_path().Reported-by: Eddie Williams
Signed-off-by: Chandra Seetharaman
Tested-by: Eddie Williams
Cc: Alasdair G Kergon
Signed-off-by: James Bottomley
Signed-off-by: James Bottomley
24 Jul, 2009
1 commit
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Incorrect device area lengths are being passed to device_area_is_valid().
The regression appeared in 2.6.31-rc1 through commit
754c5fc7ebb417b23601a6222a6005cc2e7f2913.With the dm-stripe target, the size of the target (ti->len) was used
instead of the stripe_width (ti->len/#stripes). An example of a
consequent incorrect error message is:device-mapper: table: 254:0: sdb too small for target
Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
22 Jun, 2009
9 commits
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This patch converts dm-multipath target to request-based from bio-based.
Basically, the patch just converts the I/O unit from struct bio
to struct request.
In the course of the conversion, it also changes the I/O queueing
mechanism. The change in the I/O queueing is described in details
as follows.I/O queueing mechanism change
-----------------------------
In I/O submission, map_io(), there is no mechanism change from
bio-based, since the clone request is ready for retry as it is.
However, in I/O complition, do_end_io(), there is a mechanism change
from bio-based, since the clone request is not ready for retry.In do_end_io() of bio-based, the clone bio has all needed memory
for resubmission. So the target driver can queue it and resubmit
it later without memory allocations.
The mechanism has almost no overhead.On the other hand, in do_end_io() of request-based, the clone request
doesn't have clone bios, so the target driver can't resubmit it
as it is. To resubmit the clone request, memory allocation for
clone bios is needed, and it takes some overheads.
To avoid the overheads just for queueing, the target driver doesn't
queue the clone request inside itself.
Instead, the target driver asks dm core for queueing and remapping
the original request of the clone request, since the overhead for
queueing is just a freeing memory for the clone request.As a result, the target driver doesn't need to record/restore
the information of the original request for resubmitting
the clone request. So dm_bio_details in dm_mpath_io is removed.multipath_busy()
---------------------
The target driver returns "busy", only when the following case:
o The target driver will map I/Os, if map() function is called
and
o The mapped I/Os will wait on underlying device's queue due to
their congestions, if map() function is called now.In other cases, the target driver doesn't return "busy".
Otherwise, dm core will keep the I/Os and the target driver can't
do what it wants.
(e.g. the target driver can't map I/Os now, so wants to kill I/Os.)Signed-off-by: Kiyoshi Ueda
Signed-off-by: Jun'ichi Nomura
Acked-by: Hannes Reinecke
Signed-off-by: Alasdair G Kergon -
Add .iterate_devices to 'struct target_type' to allow a function to be
called for all devices in a DM target. Implemented it for all targets
except those in dm-snap.c (origin and snapshot).(The raid1 version number jumps to 1.12 because we originally reserved
1.1 to 1.11 for 'block_on_error' but ended up using 'handle_errors'
instead.)Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
Cc: martin.petersen@oracle.com -
This patch makes two additions to the dm path selector interface for
dynamic load balancers:
o a new hook, start_io()
o a new parameter 'nr_bytes' to select_path()/start_io()/end_io()
to pass the size of the I/Ostart_io() is called when a target driver actually submits I/O
to the selected path.
Path selectors can use it to start accounting of the I/O.
(e.g. counting the number of in-flight I/Os.)
The start_io hook is based on the patch posted by Stefan Bader:
https://www.redhat.com/archives/dm-devel/2005-October/msg00050.htmlnr_bytes, the size of the I/O, is so path selectors can take the
size of the I/O into account when deciding which path to use.
dm-service-time uses it to estimate service time, for example.
(Added the nr_bytes member to dm_mpath_io instead of using existing
details.bi_size, since request-based dm patch deletes it.)Signed-off-by: Stefan Bader
Signed-off-by: Kiyoshi Ueda
Signed-off-by: Jun'ichi Nomura
Signed-off-by: Alasdair G Kergon -
Flush support for dm-multipath target.
Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
The commit fe9cf30eb8186ef267d1868dc9f12f2d0f40835a moves dm table event
submission from kmultipath queue to kernel kevent queue to avoid a
deadlock.There is a possibility of race condition because kevent queue is not flushed
in the multipath destructor. The scenario is:
- some event happens and is queued to keventd
- keventd thread is delayed due to scheuling latency or some other work
- multipath device is destroyed
- keventd now attempts to process work_struct that is residing in already
released memory.The patch flushes the keventd queue in multipath constructor.
I've already fixed similar bug in dm-raid1.Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon
Cc: stable@kernel.org -
Fixed a problem affecting reinstatement of passive paths.
Before we moved the hardware handler from dm to SCSI, it performed a pg_init
for a path group and didn't maintain any state about each path in hardware
handler code.But in SCSI dh, such state is now maintained, as we want to fail I/O early on a
path if it is not the active path.All the hardware handlers have a state now and set to active or some form of
inactive. They have prep_fn() which uses this state to fail the I/O without
it ever being sent to the device.So in effect when dm-multipath calls scsi_dh_activate(), activate is
sent to only one path and the "state" of that path is changed appropriately
to "active" while other paths in the same path group are never changed
as they never got an "activate".In order make sure all the paths in a path group gets their state set
properly when a pg_init happens, we need to call scsi_dh_activate() on
all paths in a path group.Doing this at the hardware handler layer is not a good option as we
want the multipath layer to define the relationship between path and path
groups and not the hardware handler.Attached patch sends an "activate" on each path in a path group when a
path group is switched. It also sends an activate when a path is reinstated.Signed-off-by: Chandra Seetharaman
Signed-off-by: Alasdair G Kergon -
When specifying a different hardware handler via multipath
features we should be able to override the built-in defaults.The problem here is the hardware table from scsi_dh is compiled
in and cannot be changed from userland. The multipath.conf OTOH
is purely user-defined and, what's more, the user might have a valid
reason for modifying it.
(EG EMC Clariion can well be run in PNR mode even though ALUA is
active, or the user might want to try ALUA on any as-of-yet unknown
devices)So _not_ allowing multipath to override the device handler setting
will just add to the confusion and makes error tracking even more
difficult.Signed-off-by: Hannes Reinecke
Signed-off-by: Alasdair G Kergon -
Fix arg count parsing error in hw handlers.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
The parser reads the argument count as a number but doesn't check that
sufficient arguments are supplied. This command triggers the bug:dmsetup create mpath --table "0 `blockdev --getsize /dev/mapper/cr0`
multipath 0 0 2 1 round-robin 1000 0 1 1 /dev/mapper/cr0
round-robin 0 1 1 /dev/mapper/cr1 1000"
kernel BUG at drivers/md/dm-mpath.c:530!Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon
15 Apr, 2009
1 commit
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It's used by DM and MD and generally useful, so move the bio list
helpers into bio.h.Signed-off-by: Christoph Hellwig
Acked-by: Alasdair G Kergon
Signed-off-by: Jens Axboe
06 Jan, 2009
2 commits
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The same workqueue is used both for sending uevents and processing queued I/O.
Deadlock has been reported in RHEL5 when sending a uevent was blocked waiting
for the queued I/O to be processed. Use scheduled_work() for the asynchronous
uevents instead.Signed-off-by: Alasdair G Kergon
-
Change dm_unregister_target to return void and use BUG() for error
reporting.dm_unregister_target can only fail because of programming bug in the
target driver. It can't fail because of user's behavior or disk errors.This patch changes unregister_target to return void and use BUG if
someone tries to unregister non-registered target or unregister target
that is in use.This patch removes code duplication (testing of error codes in all dm
targets) and reports bugs in just one place, in dm_unregister_target. In
some target drivers, these return codes were ignored, which could lead
to a situation where bugs could be missed.Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon