The commit fe9cf30eb8 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 <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
If the code can't handle allocation failures, use __GFP_NOFAIL so that
in case of memory pressure the allocator will retry indefinitely and
won't return NULL which would cause a crash in the function.
This is still not a correct fix, it may cause a classic deadlock when
memory manager waits for I/O being done and I/O waits for some free memory.
I/O code shouldn't allocate any memory. But in this case it probably
doesn't matter much in practice, people usually do not swap on RAID.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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 <sekharan@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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 <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Do not process sysfs attributes when device is being destroyed.
Otherwise code can cause
BUG_ON(test_bit(DMF_FREEING, &md->flags));
in dm_put() call.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Follow-up to "block: enable by default support for large devices
and files on 32-bit archs".
Rename CONFIG_LBD to CONFIG_LBDAF to:
- allow update of existing [def]configs for "default y" change
- reflect that it is used also for large files support nowadays
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for-linus' of git://neil.brown.name/md: (39 commits)
md/raid5: correctly update sync_completed when we reach max_resync
md/raid5: add missing call to schedule() after prepare_to_wait()
md/linear: use call_rcu to free obsolete 'conf' structures.
md linear: Protecting mddev with rcu locks to avoid races
md: Move check for bitmap presence to personality code.
md: remove chunksize rounding from common code.
md: raid0/linear: ensure device sizes are rounded to chunk size.
md: move assignment of ->utime so that it never gets skipped.
md: Push down reconstruction log message to personality code.
md: merge reconfig and check_reshape methods.
md: remove unnecessary arguments from ->reconfig method.
md: raid5: check stripe cache is large enough in start_reshape
md: raid0: chunk_sectors cleanups.
md: fix some comments.
md/raid5: Use is_power_of_2() in raid5_reconfig()/raid6_reconfig().
md: convert conf->chunk_size and conf->prev_chunk to sectors.
md: Convert mddev->new_chunk to sectors.
md: Make mddev->chunk_size sector-based.
md: raid0 :Enables chunk size other than powers of 2.
md: prepare for non-power-of-two chunk sizes
...
At the end of reshape_request we update cyrr_resync_completed
if we are about to pause due to reaching resync_max.
However we update it to the wrong value. We need to add the
"reshape_sectors" that have just been reshaped.
Signed-off-by: NeilBrown <neilb@suse.de>
In the unlikely event that reshape progresses past the current request
while it is waiting for a stripe we need to schedule() before retrying
for 2 reasons:
1/ Prevent list corruption from duplicated list_add() calls without
intervening list_del().
2/ Give the reshape code a chance to make some progress to resolve the
conflict.
Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Current, when we update the 'conf' structure, when adding a
drive to a linear array, we keep the old version around until
the array is finally stopped, as it is not safe to free it
immediately.
Now that we have rcu protection on all accesses to 'conf',
we can use call_rcu to free it more promptly.
Signed-off-by: NeilBrown <neilb@suse.de>
Due to the lack of memory ordering guarantees, we may have races around
mddev->conf.
In particular, the correct contents of the structure we get from
dereferencing ->private might not be visible to this CPU yet, and
they might not be correct w.r.t mddev->raid_disks.
This patch addresses the problem using rcu protection to avoid
such race conditions.
Signed-off-by: SandeepKsinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
If the superblock of a component device indicates the presence of a
bitmap but the corresponding raid personality does not support bitmaps
(raid0, linear, multipath, faulty), then something is seriously wrong
and we'd better refuse to run such an array.
Currently, this check is performed while the superblocks are examined,
i.e. before entering personality code. Therefore the generic md layer
must know which raid levels support bitmaps and which do not.
This patch avoids this layer violation without adding identical code
to various personalities. This is accomplished by introducing a new
public function to md.c, md_check_no_bitmap(), which replaces the
hard-coded checks in the superblock loading functions.
A call to md_check_no_bitmap() is added to the ->run method of each
personality which does not support bitmaps and assembly is aborted
if at least one component device contains a bitmap.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
It is easiest to round sizes to multiples of chunk size in
the personality code for those personalities which care.
Those personalities now do the rounding, so we can
remove that function from common code.
Also remove the upper bound on the size of a chunk, and the lower
bound on the size of a device (1 chunk), neither of which really buy
us anything.
Signed-off-by: NeilBrown <neilb@suse.de>
This is currently ensured by common code, but it is more reliable to
ensure it where it is needed in personality code.
All the other personalities that care already round the size to
the chunk_size. raid0 and linear are the only hold-outs.
Signed-off-by: NeilBrown <neilb@suse.de>
Currently the assignment to utime gets skipped for 'external'
metadata. So move it to the top of the function so that it
always gets effected.
This is of largely cosmetic interest. Nothing actually depends
on ->utime being right for external arrays.
"mdadm --monitor" does use it for 0.90 and 1.x arrays, but with
mdadm-3.0, this is not important for external metadata.
Signed-off-by: NeilBrown <neilb@suse.de>
Currently, the md layer checks in analyze_sbs() if the raid level
supports reconstruction (mddev->level >= 1) and if reconstruction is
in progress (mddev->recovery_cp != MaxSector).
Move that printk into the personality code of those raid levels that
care (levels 1, 4, 5, 6, 10).
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
The difference between these two methods is artificial.
Both check that a pending reshape is valid, and perform any
aspect of it that can be done immediately.
'reconfig' handles chunk size and layout.
'check_reshape' handles raid_disks.
So make them just one method.
Signed-off-by: NeilBrown <neilb@suse.de>
Passing the new layout and chunksize as args is not necessary as
the mddev has fields for new_check and new_layout.
This is preparation for combining the check_reshape and reconfig
methods
Signed-off-by: NeilBrown <neilb@suse.de>
In reshape cases that do not change the number of devices,
start_reshape is called without first calling check_reshape.
Currently, the check that the stripe_cache is large enough is
only done in check_reshape. It should be in start_reshape too.
Signed-off-by: NeilBrown <neilb@suse.de>
1/ Raid5 has learned to take over also raid4 and raid6 arrays.
2/ new_chunk in mdp_superblock_1 is in sectors, not bytes.
Signed-off-by: NeilBrown <neilb@suse.de>
A straight-forward conversion which gets rid of some
multiplications/divisions/shifts. The patch also introduces a couple
of new ones, most of which are due to conf->chunk_size still being
represented in bytes. This will be cleaned up in subsequent patches.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
This patch renames the chunk_size field to chunk_sectors with the
implied change of semantics. Since
is_power_of_2(chunk_size) = is_power_of_2(chunk_sectors << 9)
= is_power_of_2(chunk_sectors)
these bits don't need an adjustment for the shift.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (64 commits)
debugfs: use specified mode to possibly mark files read/write only
debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.
xen: remove driver_data direct access of struct device from more drivers
usb: gadget: at91_udc: remove driver_data direct access of struct device
uml: remove driver_data direct access of struct device
block/ps3: remove driver_data direct access of struct device
s390: remove driver_data direct access of struct device
parport: remove driver_data direct access of struct device
parisc: remove driver_data direct access of struct device
of_serial: remove driver_data direct access of struct device
mips: remove driver_data direct access of struct device
ipmi: remove driver_data direct access of struct device
infiniband: ehca: remove driver_data direct access of struct device
ibmvscsi: gadget: at91_udc: remove driver_data direct access of struct device
hvcs: remove driver_data direct access of struct device
xen block: remove driver_data direct access of struct device
thermal: remove driver_data direct access of struct device
scsi: remove driver_data direct access of struct device
pcmcia: remove driver_data direct access of struct device
PCIE: remove driver_data direct access of struct device
...
Manually fix up trivial conflicts due to different direct driver_data
direct access fixups in drivers/block/{ps3disk.c,ps3vram.c}
When porting blktrace to tracepoints, we changed to trace/block.h
for trace prober declarations.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Maintain two flows, one for pow2 chunk sizes (which uses masks and
shift), and a flow for the general case (which uses sector_div).
This is for the sake of performance.
- introduce map_sector and is_io_in_chunk_boundary to encapsulate
those two flows better for raid0_make_request
- fix blk_mergeable to support the two flows.
Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
Remove chunk size check from md as this is now performed in the run
function in each personality.
Replace chunk size power 2 code calculations by a regular division.
Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
have raid0 check chunk size in run method instead of in md.
This is part of a series moving the checks from common code to
the personalities where they belong.
hardsect is short and chunksize is an int, so it is safe to use %.
Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
Replace the linear search with binary search in which_dev.
Signed-off-by: Sandeep K Sinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Remove num_sectors from dev_info and replace start_sector with
end_sector. This makes a lot of comparisons much simpler.
Signed-off-by: Sandeep K Sinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Get rid of sector_div and hash table for linear raid and replace
with a linear search in which_dev.
The hash table adds a lot of complexity for little if any gain.
Ultimately a binary search will be used which will have smaller
cache foot print, a similar number of memory access, and no
divisions.
Signed-off-by: Sandeep K Sinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Having a macro just to cast a void* isn't really helpful.
I would must rather see that we are simply de-referencing ->private,
than have to know what the macro does.
So open code the macro everywhere and remove the pointless cast.
Signed-off-by: NeilBrown <neilb@suse.de>
This setting doesn't seem to make sense (half the chunk size??) and
shouldn't be needed.
The segment boundary exported by raid0 should simply be the minimum
of the segment boundary of all component devices. And we already
get that right.
Signed-off-by: NeilBrown <neilb@suse.de>
If we treat conf->devlist more like a 2 dimensional array,
we can get the devlist for a particular zone simply by indexing
that array, so we don't need to store the pointers to subarrays
in strip_zone. This makes strip_zone smaller and so (hopefully)
searches faster.
Signed-of-by: NeilBrown <neilb@suse.de>
storing ->sectors is redundant as is can be computed from the
difference z->zone_end - (z-1)->zone_end
The one place where it is used, it is just as efficient to use
a zone_end value instead.
And removing it makes strip_zone smaller, so they array of these that
is searched on every request has a better chance to say in cache.
So discard the field and get the value from elsewhere.
Signed-off-by: NeilBrown <neilb@suse.de>
raid0_stop() removes all references to the raid0 configuration but
misses to free the ->devlist buffer.
This patch closes this leak, removes a pointless initialization and
fixes a coding style issue in raid0_stop().
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Currently the raid0 configuration is allocated in raid0_run() while
the buffers for the strip_zone and the dev_list arrays are allocated
in create_strip_zones(). On errors, all three buffers are freed
in raid0_run().
It's easier and more readable to do the allocation and cleanup within
a single function. So move that code into create_strip_zones().
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Currently raid0_run() always returns -ENOMEM on errors. This is
incorrect as running the array might fail for other reasons, for
example because not all component devices were available.
This patch changes create_strip_zones() so that it returns a proper
error code (either -ENOMEM or -EINVAL) rather than 1 on errors and
makes raid0_run(), its single caller, return that value instead
of -ENOMEM.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
The "sector_shift" and "spacing" fields of struct raid0_private_data
were only used for the hash table lookups. So the removal of the
hash table allows get rid of these fields as well which simplifies
create_strip_zones() and raid0_run() quite a bit.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
The raid0 hash table has become unused due to the changes in the
previous patch. This patch removes the hash table allocation and
setup code and kills the hash_table field of struct raid0_private_data.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
1/ remove current_start. The same value is available in
zone->dev_start and storing it separately doesn't gain anything.
2/ rename curr_zone_start to curr_zone_end as we are now more
focused on the 'end' of each zone. We end up storing the
same number though - the old name was a little confusing
(and what does 'current' mean in this context anyway).
Signed-off-by: NeilBrown <neilb@suse.de>
