When we read the write-intent-bitmap off the device, we currently
read a whole number of pages.
When PAGE_SIZE is 4K, this works due to the alignment we enforce
on the superblock and bitmap.
When PAGE_SIZE is 64K, this case read past the end-of-device
which causes an error.
When we write the superblock, we ensure to clip the last page
to just be the required size. Copy that code into the read path
to just read the required number of sectors.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: stable@kernel.org
Fix setting of max_segment_size and seg_boundary mask for stacked md/dm
devices.
When stacking devices (LVM over MD over SCSI) some of the request queue
parameters are not set up correctly in some cases by default, namely
max_segment_size and and seg_boundary mask.
If you create MD device over SCSI, these attributes are zeroed.
Problem become when there is over this mapping next device-mapper mapping
- queue attributes are set in DM this way:
request_queue max_segment_size seg_boundary_mask
SCSI 65536 0xffffffff
MD RAID1 0 0
LVM 65536 -1 (64bit)
Unfortunately bio_add_page (resp. bio_phys_segments) calculates number of
physical segments according to these parameters.
During the generic_make_request() is segment cout recalculated and can
increase bio->bi_phys_segments count over the allowed limit. (After
bio_clone() in stack operation.)
Thi is specially problem in CCISS driver, where it produce OOPS here
BUG_ON(creq->nr_phys_segments > MAXSGENTRIES);
(MAXSEGENTRIES is 31 by default.)
Sometimes even this command is enough to cause oops:
dd iflag=direct if=/dev/<vg>/<lv> of=/dev/null bs=128000 count=10
This command generates bios with 250 sectors, allocated in 32 4k-pages
(last page uses only 1024 bytes).
For LVM layer, it allocates bio with 31 segments (still OK for CCISS),
unfortunatelly on lower layer it is recalculated to 32 segments and this
violates CCISS restriction and triggers BUG_ON().
The patch tries to fix it by:
* initializing attributes above in queue request constructor
blk_queue_make_request()
* make sure that blk_queue_stack_limits() inherits setting
(DM uses its own function to set the limits because it
blk_queue_stack_limits() was introduced later. It should probably switch
to use generic stack limit function too.)
* sets the default seg_boundary value in one place (blkdev.h)
* use this mask as default in DM (instead of -1, which differs in 64bit)
Bugs related to this:
https://bugzilla.redhat.com/show_bug.cgi?id=471639http://bugzilla.kernel.org/show_bug.cgi?id=8672
Signed-off-by: Milan Broz <mbroz@redhat.com>
Reviewed-by: Alasdair G Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Mike Miller <mike.miller@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Port to the new tracepoints API: split DEFINE_TRACE() and DECLARE_TRACE()
sites. Spread them out to the usage sites, as suggested by
Mathieu Desnoyers.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
This was a forward port of work done by Mathieu Desnoyers, I changed it to
encode the 'what' parameter on the tracepoint name, so that one can register
interest in specific events and not on classes of events to then check the
'what' parameter.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
dm_any_congested() just checks for the DMF_BLOCK_IO and has no
code to make sure that suspend waits for dm_any_congested() to
complete. This patch adds such a check.
Without it, a race can occur with dm_table_put() attempting to
destroying the table in the wrong thread, the one running
dm_any_congested() which is meant to be quick and return
immediately.
Two examples of problems:
1. Sleeping functions called from congested code, the caller
of which holds a spin lock.
2. An ABBA deadlock between pdflush and multipathd. The two locks
in contention are inode lock and kernel lock.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This doesn't fix any bug, just moves wake_up immediately after decrementing
md->pending, for better code readability.
It must be clear to anyone manipulating md->pending to wake up
the queue if md->pending reaches zero, so move the wakeup as close to
the decrementing as possible.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Currently dm ignores the parameters provided to hardware handlers
without providing any notifications to the user.
This patch just prints a warning message so that the user knows that
the arguments are ignored.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Path activation code is called even when the pgpath is NULL. This could
lead to a panic in activate_path(). Such a panic is seen in -rt kernel.
This problem has been there before the pg_init() was moved to a
workqueue.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Don't proceed if dm_stripe_init() fails to register itself as a dm target.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
We queue work on keventd queue --- so this queue must be flushed in the
destructor. Otherwise, keventd could access mirror_set after it was freed.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
We currently oops with a divide error on starting a linear software
raid array consisting of at least two very small (< 500K) devices.
The bug is caused by the calculation of the hash table size which
tries to compute sector_div(sz, base) with "base" being zero due to
the small size of the component devices of the array.
Fix this by requiring the hash spacing to be at least one which
implies that also "base" is non-zero.
This bug has existed since about 2.6.14.
Cc: stable@kernel.org
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Adding a spare to a raid10 doesn't cause recovery to start.
This is due to an silly type in
commit 6c2fce2ef6
and so is a bug in 2.6.27 and .28-rc.
Thanks to Thomas Backlund for bisecting to find this.
Cc: Thomas Backlund <tmb@mandriva.org>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
It turns out that it is only safe to call blkdev_ioctl when the device
is actually open (as ->bd_disk is set to NULL on last close). And it
is quite possible for do_md_stop to be called when the device is not
open. So discard the call to blkdev_ioctl(BLKRRPART) which was
added in
commit 934d9c23b4
It is just as easy to call this ioctl from userspace when needed (on
mdadm -S) so leave it out of the kernel
Signed-off-by: NeilBrown <neilb@suse.de>
If there are several snapshots sharing an origin and one is removed
while the origin is being written to, the snapshot's mempool may get
deleted while elements are still referenced.
Prior to dm-snapshot-use-per-device-mempools.patch the pending
exceptions may still have been referenced after the snapshot was
destroyed, but this was not a problem because the shared mempool
was still there.
This patch fixes the problem by tracking the number of mempool elements
in use.
The scenario:
- You have an origin and two snapshots 1 and 2.
- Someone writes to the origin.
- It creates two exceptions in the snapshots, snapshot 1 will be primary
exception, snapshot 2's pending_exception->primary_pe will point to the
exception in snapshot 1.
- The exceptions are being relocated, relocation of exception 1 finishes
(but it's pending_exception is still allocated, because it is referenced
by an exception from snapshot 2)
- The user lvremoves snapshot 1 --- it calls just suspend (does nothing)
and destructor. md->pending is zero (there is no I/O submitted to the
snapshot by md layer), so it won't help us.
- The destructor waits for kcopyd jobs to finish on snapshot 1 --- but
there are none.
- The destructor on snapshot 1 cleans up everything.
- The relocation of exception on snapshot 2 finishes, it drops reference
on primary_pe. This frees its primary_pe pointer. Primary_pe points to
pending exception created for snapshot 1. So it frees memory into
non-existing mempool.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
register_snapshot() performs a GFP_KERNEL allocation while holding
_origins_lock for write, but that could write out dirty pages onto a
device that attempts to acquire _origins_lock for read, resulting in
deadlock.
So move the allocation up before taking the lock.
This path is not performance-critical, so it doesn't matter that we
allocate memory and free it if we find that we won't need it.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
md arrays are not currently destroyed when they are stopped - they
remain in /sys/block. Last time I tried this I tripped over locking
too much.
A consequence of this is that udev doesn't remove anything from /dev.
This is rather ugly.
As an interim measure until proper device removal can be achieved,
make sure all partitions are removed using the BLKRRPART ioctl, and
send a KOBJ_CHANGE when an md array is stopped.
Signed-off-by: NeilBrown <neilb@suse.de>
* 'for-linus' of git://neil.brown.name/md:
md: allow extended partitions on md devices.
md: use sysfs_notify_dirent to notify changes to md/dev-xxx/state
md: use sysfs_notify_dirent to notify changes to md/array_state
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev: (66 commits)
[PATCH] kill the rest of struct file propagation in block ioctls
[PATCH] get rid of struct file use in blkdev_ioctl() BLKBSZSET
[PATCH] get rid of blkdev_locked_ioctl()
[PATCH] get rid of blkdev_driver_ioctl()
[PATCH] sanitize blkdev_get() and friends
[PATCH] remember mode of reiserfs journal
[PATCH] propagate mode through swsusp_close()
[PATCH] propagate mode through open_bdev_excl/close_bdev_excl
[PATCH] pass fmode_t to blkdev_put()
[PATCH] kill the unused bsize on the send side of /dev/loop
[PATCH] trim file propagation in block/compat_ioctl.c
[PATCH] end of methods switch: remove the old ones
[PATCH] switch sr
[PATCH] switch sd
[PATCH] switch ide-scsi
[PATCH] switch tape_block
[PATCH] switch dcssblk
[PATCH] switch dasd
[PATCH] switch mtd_blkdevs
[PATCH] switch mmc
...
Now that lookup_bdev is exported and used by dm just use it directly
instead of through a trivial wrapper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch tidies local_init() in preparation for request-based 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>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch removes the DM_WQ_FLUSH_ALL state that is unnecessary.
The dm_queue_flush(md, DM_WQ_FLUSH_ALL, NULL) in dm_suspend()
is never invoked because:
- 'goto flush_and_out' is the same as 'goto out' because
the 'goto flush_and_out' is called only when '!noflush'
- If r is non-zero, then the code above will invoke 'goto out'
and skip this code.
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: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Separate the region hash code from raid1 so it can be shared by forthcoming
targets. Use BUG_ON() for failed async dm_io() calls.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
When a bio gets split, mark its fragments with the BIO_CLONED flag.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove waitqueue no longer needed with the async crypto interface.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
When writing io, dm-crypt has to allocate a new cloned bio
and encrypt the data into newly-allocated pages attached to this bio.
In rare cases, because of hw restrictions (e.g. physical segment limit)
or memory pressure, sometimes more than one cloned bio has to be used,
each processing a different fragment of the original.
Currently there is one waitqueue which waits for one fragment to finish
and continues processing the next fragment.
But when using asynchronous crypto this doesn't work, because several
fragments may be processed asynchronously or in parallel and there is
only one crypt context that cannot be shared between the bio fragments.
The result may be corruption of the data contained in the encrypted bio.
The patch fixes this by allocating new dm_crypt_io structs (with new
crypto contexts) and running them independently.
The fragments contains a pointer to the base dm_crypt_io struct to
handle reference counting, so the base one is properly deallocated
after all the fragments are finished.
In a low memory situation, this only uses one additional object from the
mempool. If the mempool is empty, the next allocation simple waits for
previous fragments to complete.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Prepare local sector variable (offset) for later patch.
Do not update io->sector for still-running I/O.
No functional change.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Change #include "dm.h" to #include <linux/device-mapper.h> in all targets.
Targets should not need direct access to internal DM structures.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move array_too_big to include/linux/device-mapper.h because it is
used by targets.
Remove the test from dm-raid1 as the number of mirror legs is limited
such that it can never fail. (Even for stripes it seems rather
unlikely.)
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
We must zero the next chunk on disk *before* writing out the current chunk, not
after. Otherwise if the machine crashes at the wrong time, the "end of metadata"
marker may be missing.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
Use a separate buffer for writing zeroes to the on-disk snapshot
exception store, make the updating of ps->current_area explicit and
refactor the code in preparation for the fix in the next patch.
No functional change.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
The last_percent field is unused - remove it.
(It dates from when events were triggered as each X% filled up.)
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Fix a race condition with primary_pe ref_count handling.
put_pending_exception runs under dm_snapshot->lock, it does atomic_dec_and_test
on primary_pe->ref_count, and later does atomic_read primary_pe->ref_count.
__origin_write does atomic_dec_and_test on primary_pe->ref_count without holding
dm_snapshot->lock.
This opens the following race condition:
Assume two CPUs, CPU1 is executing put_pending_exception (and holding
dm_snapshot->lock). CPU2 is executing __origin_write in parallel.
primary_pe->ref_count == 2.
CPU1:
if (primary_pe && atomic_dec_and_test(&primary_pe->ref_count))
origin_bios = bio_list_get(&primary_pe->origin_bios);
... decrements primary_pe->ref_count to 1. Doesn't load origin_bios
CPU2:
if (first && atomic_dec_and_test(&primary_pe->ref_count)) {
flush_bios(bio_list_get(&primary_pe->origin_bios));
free_pending_exception(primary_pe);
/* If we got here, pe_queue is necessarily empty. */
return r;
}
... decrements primary_pe->ref_count to 0, submits pending bios, frees
primary_pe.
CPU1:
if (!primary_pe || primary_pe != pe)
free_pending_exception(pe);
... this has no effect.
if (primary_pe && !atomic_read(&primary_pe->ref_count))
free_pending_exception(primary_pe);
... sees ref_count == 0 (written by CPU 2), does double free !!
This bug can happen only if someone is simultaneously writing to both the
origin and the snapshot.
If someone is writing only to the origin, __origin_write will submit kcopyd
request after it decrements primary_pe->ref_count (so it can't happen that the
finished copy races with primary_pe->ref_count decrementation).
If someone is writing only to the snapshot, __origin_write isn't invoked at all
and the race can't happen.
The race happens when someone writes to the snapshot --- this creates
pending_exception with primary_pe == NULL and starts copying. Then, someone
writes to the same chunk in the snapshot, and __origin_write races with
termination of already submitted request in pending_complete (that calls
put_pending_exception).
This race may be reason for bugs:
http://bugzilla.kernel.org/show_bug.cgi?id=11636https://bugzilla.redhat.com/show_bug.cgi?id=465825
The patch fixes the code to make sure that:
1. If atomic_dec_and_test(&primary_pe->ref_count) returns false, the process
must no longer dereference primary_pe (because someone else may free it under
us).
2. If atomic_dec_and_test(&primary_pe->ref_count) returns true, the process
is responsible for freeing primary_pe.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
Write throughput to LVM snapshot origin volume is an order
of magnitude slower than those to LV without snapshots or
snapshot target volumes, especially in the case of sequential
writes with O_SYNC on.
The following patch originally written by Kevin Jamieson and
Jan Blunck and slightly modified for the current RCs by myself
tries to improve the performance by modifying the behaviour
of kcopyd, so that it pushes back an I/O job to the head of
the job queue instead of the tail as process_jobs() currently
does when it has to wait for free pages. This way, write
requests aren't shuffled to cause extra seeks.
I tested the patch against 2.6.27-rc5 and got the following results.
The test is a dd command writing to snapshot origin followed by fsync
to the file just created/updated. A couple of filesystem benchmarks
gave me similar results in case of sequential writes, while random
writes didn't suffer much.
dd if=/dev/zero of=<somewhere on snapshot origin> bs=4096 count=...
[conv=notrunc when updating]
1) linux 2.6.27-rc5 without the patch, write to snapshot origin,
average throughput (MB/s)
10M 100M 1000M
create,dd 511.46 610.72 11.81
create,dd+fsync 7.10 6.77 8.13
update,dd 431.63 917.41 12.75
update,dd+fsync 7.79 7.43 8.12
compared with write throughput to LV without any snapshots,
all dd+fsync and 1000 MiB writes perform very poorly.
10M 100M 1000M
create,dd 555.03 608.98 123.29
create,dd+fsync 114.27 72.78 76.65
update,dd 152.34 1267.27 124.04
update,dd+fsync 130.56 77.81 77.84
2) linux 2.6.27-rc5 with the patch, write to snapshot origin,
average throughput (MB/s)
10M 100M 1000M
create,dd 537.06 589.44 46.21
create,dd+fsync 31.63 29.19 29.23
update,dd 487.59 897.65 37.76
update,dd+fsync 34.12 30.07 26.85
Although still not on par with plain LV performance -
cannot be avoided because it's copy on write anyway -
this simple patch successfully improves throughtput
of dd+fsync while not affecting the rest.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Kazuo Ito <ito.kazuo@oss.ntt.co.jp>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
To keep the size of changesets sane we split the switch by drivers;
to keep the damn thing bisectable we do the following:
1) rename the affected methods, add ones with correct
prototypes, make (few) callers handle both. That's this changeset.
2) for each driver convert to new methods. *ALL* drivers
are converted in this series.
3) kill the old (renamed) methods.
Note that it _is_ a flagday; all in-tree drivers are converted and by the
end of this series no trace of old methods remain. The only reason why
we do that this way is to keep the damn thing bisectable and allow per-driver
debugging if anything goes wrong.
New methods:
open(bdev, mode)
release(disk, mode)
ioctl(bdev, mode, cmd, arg) /* Called without BKL */
compat_ioctl(bdev, mode, cmd, arg)
locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Analog of blkdev_driver_ioctl() with sane arguments. For
now uses fake struct file, by the end of the series it won't
and blkdev_driver_ioctl() will become a wrapper around it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The new extended partition support provides a much nicer was
to have partitions on md devices that the 'mdp' alternate major.
We cannot really get rid of 'mdp' at this time, but we can
enable extended partitions as that will probably make life
easier for sysadmins.
Signed-off-by: NeilBrown <neilb@suse.de>
The 'state' file for a device reports, for example, when the device
has failed. Changes should be reported to userspace ASAP without
the possibility of blocking on low-memory. sysfs_notify does
have that possibility (as it takes a mutex which can be held
across a kmalloc) so use sysfs_notify_dirent instead.
Signed-off-by: NeilBrown <neilb@suse.de>
Now that we have sysfs_notify_dirent, use it to notify changes
to md/array_state.
As sysfs_notify_dirent can be called in atomic context, we can
remove the delayed notify and the MD_NOTIFY_ARRAY_STATE flag.
Signed-off-by: NeilBrown <neilb@suse.de>
* 'for-linus' of git://neil.brown.name/md:
md: fix input truncation in safe_delay_store()
md: check for memory allocation failure in faulty personality
md: build failure due to missing delay.h
md: Relax minimum size restrictions on chunk_size.
md: remove space after function name in declaration and call.
md: Remove unnecessary #includes, #defines, and function declarations.
md: Convert remaining 1k representations in linear.c to sectors.
md: linear.c: Make two local variables sector-based.
md: linear: Represent dev_info->size and dev_info->offset in sectors.
md: linear.c: Remove broken debug code.
md: linear.c: Remove pointless initialization of curr_offset.
md: linear.c: Fix typo in comment.
md: Don't try to set an array to 'read-auto' if it is already in that state.
md: Allow metadata_version to be updated for externally managed metadata.
md: Fix rdev_size_store with size == 0
safe_delay_store() currently truncates the last character of input since
it tells strlcpy that the buffer can only hold 'len' characters, off by
one. sysfs already null terminates the buffer, so just increase the
last argument to strlcpy.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
It's a fault injection module, but I don't think we should oops here.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Today's linux-next build (powerpc ppc64_defconfig) failed like this:
drivers/md/raid1.c: In function 'sync_request':
drivers/md/raid1.c:1759: error: implicit declaration of function 'msleep_interruptible'
make[3]: *** [drivers/md/raid1.o] Error 1
make[3]: *** Waiting for unfinished jobs....
drivers/md/raid10.c: In function 'sync_request':
drivers/md/raid10.c:1749: error: implicit declaration of function 'msleep_interruptible'
make[3]: *** [drivers/md/raid10.o] Error 1
drivers/md/md.c: In function 'md_do_sync':
drivers/md/md.c:5915: error: implicit declaration of function 'msleep'
Caused by commit 6caa3b0bbdb474647f6bdd8a958ffc46f78d8d58 ("md: Remove
unnecessary #includes, #defines, and function declarations"). I added
the following patch.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NeilBrown <neilb@suse.de>
Multipath is best at handling transport errors. If it gets a device
error then there is not much the multipath layer can do. It will just
access the same device but from a different path.
This patch breaks up failfast into device, transport and driver errors.
The multipath layers (md and dm mutlipath) only ask the lower levels to
fast fail transport errors. The user of failfast, read ahead, will ask
to fast fail on all errors.
Note that blk_noretry_request will return true if any failfast bit
is set. This allows drivers that do not support the multipath failfast
bits to continue to fail on any failfast error like before. Drivers
like scsi that are able to fail fast specific errors can check
for the specific fail fast type. In the next patch I will convert
scsi.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Currently, the 'chunk_size' of an array must be at-least PAGE_SIZE.
This makes moving an array to a machine with a larger PAGE_SIZE, or
changing the kernel to use a larger PAGE_SIZE, can stop an array from
working.
For RAID10 and RAID4/5/6, this is non-trivial to fix as the resync
process works on whole pages at a time, and assumes them to be wholly
within a stripe. For other raid personalities, this restriction is
not needed at all and can be dropped.
So remove the test on chunk_size from common can, and add it in just
the places where it is needed: raid10 and raid4/5/6.
Signed-off-by: NeilBrown <neilb@suse.de>
Having
function (args)
instead of
function(args)
make is harder to search for calls of particular functions.
So remove all those spaces.
Signed-off-by: NeilBrown <neilb@suse.de>
This patch renames hash_spacing and preshift to spacing and
sector_shift respectively with the following change of semantics:
Case 1: (sizeof(sector_t) <= sizeof(u32)).
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In this case, we have sector_shift = preshift = 0 and spacing =
2 * hash_spacing.
Hence, the index for the hash table which is computed by the new code
in which_dev() as sector / spacing equals the old value which was
(sector/2) / hash_spacing.
Note also that the value of nb_zone stays the same because both sz
and base double.
Case 2: (sizeof(sector_t) > sizeof(u32)).
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(aka the shifting dance case). Here we have sector_shift = preshift +
1 and
spacing = 2 * hash_spacing
during the computation of nb_zone and curr_sector, but
spacing = hash_spacing
in which_dev() because in the last hunk of the patch for linear.c we
shift down conf->spacing (= 2 * hash_spacing) by one more bit than
in the old code.
Hence in the computation of nb_zone, sz and base have the same value
as before, so nb_zone is not affected. Also curr_sector in the next
hunk stays the same.
In which_dev() the hash table index is computed as
(sector >> sector_shift) / spacing
In view of sector_shift = preshift + 1 and spacing = hash_spacing,
this equals
((sector/2) >> preshift) / hash_spacing
which is the value computed by the old code.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
This is a preparation for representing also the remaining fields of struct
linear_private_data as sectors.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Rename them to num_sectors and start_sector which is more descriptive.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
conf->smallest_size is undefined since day one of the git repo..
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
'read-auto' is a variant of 'readonly' which will switch to writable
on the first write attempt.
Calling do_md_stop to set the array readonly when it is already readonly
returns an error. So make sure not to do that.
Signed-off-by: NeilBrown <neilb@suse.de>
For externally managed metadata, the 'metadata_version' sysfs
attribute is really just a channel for user-space programs to
communicate about how the array is being managed.
It can be useful for this to be changed while the array is active.
Normally changes to metadata_version are not permitted while the array
is active. Change that so that if the metadata is externally managed,
the metadata_version can be changed to a different flavour of external
management.
Signed-off-by: NeilBrown <neilb@suse.de>
Fix rdev_size_store with size == 0.
size == 0 means to use the largest size allowed by the
underlying device and is used when modifying an active array.
This fixes a regression introduced by
commit d7027458d6
Cc: <stable@kernel.org>
Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: NeilBrown <neilb@suse.de>
RAID autodetect has the side effect of requiring synchronisation
of all device drivers, which can make the boot several seconds longer
(I've measured 7 on one of my laptops).... even for systems that don't
have RAID setup for the root filesystem (the only FS where this matters).
This patch makes the default for autodetect a config option; either way
the user can always override via the kernel command line.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: NeilBrown <neilb@suse.de>
Detect and report buggy drivers that destroy their request_queue.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Stefan Raspl <raspl@linux.vnet.ibm.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Publish dm_vcalloc in include/linux/device-mapper.h because this function is
used by targets.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Publish dm_table_unplug_all in include/linux/device-mapper.h because this
function is used by targets.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Publish dm_get_mapinfo in include/linux/device-mapper.h because this function
is used by targets.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Split struct dm_dev in two and publish the part that other targets need in
include/linux/device-mapper.h.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Don't wait between submitting crypt requests for a bio unless
we are short of memory.
There are two situations when we must split an encrypted bio:
1) there are no free pages;
2) the new bio would violate underlying device restrictions
(e.g. max hw segments).
In case (2) we do not need to wait.
Add output variable to crypt_alloc_buffer() to distinguish between
these cases.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move the initialisation of ctx->pending into one place, at the
start of crypt_convert().
Introduce crypt_finished to indicate whether or not the encryption
is finished, for use in a later patch.
No functional change.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The pending reference count must be incremented *before* the async work is
queued to another thread, not after. Otherwise there's a race if the
work completes and decrements the reference count before it gets incremented.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Make kcryptd_crypt_write_io_submit() responsible for decrementing
the pending count after an error.
Also fixes a bug in the async path that forgot to decrement it.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Make the caller reponsible for incrementing the pending count before calling
kcryptd_crypt_write_io_submit() in the non-async case to bring it into line
with the async case.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move kcryptd_crypt_write_convert_loop inside kcryptd_crypt_write_convert.
This change is needed for a later patch.
No functional change.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Factor out crypt io allocation code.
Later patches will call it from another place.
No functional change.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move io pending to one place.
No functional change, usefull to simplify debugging.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Change uint32_t into chunk_t to remove 32-bit limitation on the
number of chunks on systems with 64-bit sector numbers.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move this logic to a function, because it will be reused later.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
dm-raid1 is setting the 'DM_KCOPYD_IGNORE_ERROR' flag unconditionally
when assigning kcopyd work. kcopyd is responsible for copying an
assigned section of disk to one or more other disks. The
'DM_KCOPYD_IGNORE_ERROR' flag affects kcopyd in the following way:
When not set:
kcopyd will immediately stop the copy operation when an error is
encountered.
When set:
kcopyd will try to proceed regardless of errors and try to continue
copying any remaining amount.
Since dm-raid1 tracks regions of the address space that are (or
are not) in sync and it now has the ability to handle these
errors, we can safely enable this optimization. This optimization
is conditional on whether mirror error handling has been enabled.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch moves 'is_active' from struct dm_path to struct pgpath
as it does not need exporting.
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 allows path errors from the multipath ctr function to
propagate up to userspace as errno values from the ioctl() call.
This is in response to
https://www.redhat.com/archives/dm-devel/2008-May/msg00000.html
and
https://bugzilla.redhat.com/show_bug.cgi?id=444421
The patch only lets through the errors that it needs to in order to
get the path errors from parse_path().
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Since all bio_split calls refer the same single bio_split_pool, the bio_split
function can use bio_split_pool directly instead of the mempool_t parameter;
then the mempool_t parameter can be removed from bio_split param list, and
bio_split_pool is only referred in fs/bio.c file, can be marked static.
Signed-off-by: Denis ChengRq <crquan@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Move stats related fields - stamp, in_flight, dkstats - from disk to
part0 and unify stat handling such that...
* part_stat_*() now updates part0 together if the specified partition
is not part0. ie. part_stat_*() are now essentially all_stat_*().
* {disk|all}_stat_*() are gone.
* part_round_stats() is updated similary. It handles part0 stats
automatically and disk_round_stats() is killed.
* part_{inc|dec}_in_fligh() is implemented which automatically updates
part0 stats for parts other than part0.
* disk_map_sector_rcu() is updated to return part0 if no part matches.
Combined with the above changes, this makes NULL special case
handling in callers unnecessary.
* Separate stats show code paths for disk are collapsed into part
stats show code paths.
* Rename disk_stat_lock/unlock() to part_stat_lock/unlock()
While at it, reposition stat handling macros a bit and add missing
parentheses around macro parameters.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Till now, bdev->bd_part is set only if the bdev was for parts other
than part0. This patch makes bdev->bd_part always set so that code
paths don't have to differenciate common handling.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Implement {disk|part}_to_dev() and use them to access generic device
instead of directly dereferencing {disk|part}->dev. To make sure no
user is left behind, rename generic devices fields to __dev.
This is in preparation of unifying partition 0 handling with other
partitions.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
There are two variants of stat functions - ones prefixed with double
underbars which don't care about preemption and ones without which
disable preemption before manipulating per-cpu counters. It's unclear
whether the underbarred ones assume that preemtion is disabled on
entry as some callers don't do that.
This patch unifies diskstats access by implementing disk_stat_lock()
and disk_stat_unlock() which take care of both RCU (for partition
access) and preemption (for per-cpu counter access). diskstats access
should always be enclosed between the two functions. As such, there's
no need for the versions which disables preemption. They're removed
and double underbars ones are renamed to drop the underbars. As an
extra argument is added, there's no danger of using the old version
unconverted.
disk_stat_lock() uses get_cpu() and returns the cpu index and all
diskstat functions which access per-cpu counters now has @cpu
argument to help RT.
This change adds RCU or preemption operations at some places but also
collapses several preemption ops into one at others. Overall, the
performance difference should be negligible as all involved ops are
very lightweight per-cpu ones.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Implement disk_devt() and part_devt() and use them to directly
access devt instead of computing it from ->major and ->first_minor.
Note that all references to ->major and ->first_minor outside of
block layer is used to determine devt of the disk (the part0) and as
->major and ->first_minor will continue to represent devt for the
disk, converting these users aren't strictly necessary. However,
convert them for consistency.
* Implement disk_max_parts() to avoid directly deferencing
genhd->minors.
* Update bdget_disk() such that it doesn't assume consecutive minor
space.
* Move devt computation from register_disk() to add_disk() and make it
the only one (all other usages use the initially determined value).
These changes clean up the code and will help disk->part dereference
fix and extended block device numbers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
raid5 can overflow with more than 255 stripes, and we can increase it
to an int for free on both 32 and 64-bit archs due to the padding.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Remove hw_segments field from struct bio and struct request. Without virtual
merge accounting they have no purpose.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Moving the path activation to workqueue along with scsi_dh patches introduced
a race. It is due to the fact that the current_pgpath (in the multipath data
structure) can be modified if changes happen in any of the paths leading to
the lun. If the changes lead to current_pgpath being set to NULL, then it
leads to the invalid access which results in the panic below.
This patch fixes that by storing the pgpath to activate in the multipath data
structure and properly protecting it.
Note that if activate_path is called twice in succession with different pgpath,
with the second one being called before the first one is done, then activate
path will be called twice for the second pgpath, which is fine.
Unable to handle kernel paging request for data at address 0x00000020
Faulting instruction address: 0xd000000000aa1844
cpu 0x1: Vector: 300 (Data Access) at [c00000006b987a80]
pc: d000000000aa1844: .activate_path+0x30/0x218 [dm_multipath]
lr: c000000000087a2c: .run_workqueue+0x114/0x204
sp: c00000006b987d00
msr: 8000000000009032
dar: 20
dsisr: 40000000
current = 0xc0000000676bb3f0
paca = 0xc0000000006f3680
pid = 2528, comm = kmpath_handlerd
enter ? for help
[c00000006b987da0] c000000000087a2c .run_workqueue+0x114/0x204
[c00000006b987e40] c000000000088b58 .worker_thread+0x120/0x144
[c00000006b987f00] c00000000008ca70 .kthread+0x78/0xc4
[c00000006b987f90] c000000000027cc8 .kernel_thread+0x4c/0x68
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If for any reason dm_merge_bvec() is given an offset beyond the end of the
device, avoid an oops and always allow one page to be added to an empty bio.
We'll reject the I/O later after the bio is submitted.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Ingo Molnar
NeilBrown
Milan Broz
Arnaldo Carvalho de Melo
Chandra Seetharaman
Mikulas Patocka
Heinz Mauelshagen
Andre Noll
Linus Torvalds
Ilpo Jarvinen
Christoph Hellwig
Kiyoshi Ueda
Heinz Mauelshagen
Martin K. Petersen
Alasdair G Kergon
Kazuo Ito
Al Viro
Dan Williams
Sven Wegener
Stephen Rothwell
Mike Christie
Chris Webb
Alan Jenkins
Arjan van de Ven
Jonathan Brassow
Benjamin Marzinski
Denis ChengRq
Mike Anderson
Tejun Heo
Jens Axboe