Ranges will be placed in the same cell if they overlap.
Range locking is a prerequisite for more efficient multi-block discard
support in both the cache and thin-provisioning targets.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Before, if the user wanted sequential IO to be promoted to the cache
they'd have to set sequential_threshold to some nebulous large value.
Now, the user may easily disable sequential IO detection (and sequential
IO's implicit bypass of the cache) by setting sequential_threshold to 0.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Rather than maintaining a separate promote_threshold variable that we
periodically update we now use the hit count of the oldest clean
block. Also add a fudge factor to discourage demoting dirty blocks.
With some tests this has a sizeable difference, because the old code
was too eager to demote blocks. For example, device-mapper-test-suite's
git_extract_cache_quick test goes from taking 190 seconds, to 142
(linear on spindle takes 250).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When creating new devices dm_sync_table() calls
synchronize_rcu_expedited(), causing _all_ pending RCU pointers to be
flushed. This causes a latency overhead that is especially noticeable
when creating lots of devices.
And all of this is pointless as there are no old maps to be
disconnected, and hence no stale pointers which would need to be
cleared up.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Annotate the map field with __rcu since this is a rcu pointer which is checked
by sparse.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The map field in 'struct mapped_device' is an rcu pointer. Use rcu_dereference()
while accessing it.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Sort the cells in logical block order before processing each cell in
process_thin_deferred_cells(). This significantly improves the ondisk
layout on rotational storage, whereby improving read performance.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This use of direct submission in process_shared_bio() reduces latency
for submitting bios in the shared cell by avoiding adding those bios to
the deferred list and waiting for the next iteration of the worker.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This use of direct submission in process_prepared_mapping() reduces
latency for submitting bios in a cell by avoiding adding those bios to
the deferred list and waiting for the next iteration of the worker.
But this direct submission exposes the potential for a race between
releasing a cell and incrementing deferred set. Fix this by introducing
dm_cell_visit_release() and refactoring inc_remap_and_issue_cell()
accordingly.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This avoids dropping the cell, so increases the probability that other
bios will collect within the cell, rather than being passed individually
to the worker.
Also add required process_cell and process_discard_cell error handling
wrappers and set associated pool-mode function pointers accordingly.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When processing a discard bio, if the block is already quiesced do the
discard immediately rather than adding the mapping to a list for the
next iteration of the worker thread.
Discarding a fully provisioned 100G thin volume with 64k block size goes
from 860s to 95s with this change.
Clearly there's something wrong with the worker architecture, more
investigation needed.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Introduce thin_merge so that any additional constraints from the data
volume may be taken into account when determing the maximum number of
sectors that can be issued relative to the specified logical offset.
This is particularly important if/when the data volume is layered ontop
of a more sophisticated device (e.g. dm-raid or some other DM target).
Reviewed-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
These code changes do not introduce a functional change.
But bio_add_page() will never attempt to build up a bio larger than
queue_max_sectors(). Similarly, bio_get_nr_vecs() is also bound by
queue_max_sectors(). Therefore, there is no point in allowing
dm_merge_bvec() to answer "how many sectors can a bio have at this
offset?" with anything larger than queue_max_sectors(). Using
queue_max_sectors() rather than BIO_MAX_SECTORS serves to more
accurately convey the limits that are being imposed.
Also, use unlikely() to clarify the fact that the defensive code in
dm_merge_bvec() relative to max_size going negative shouldn't ever
happen -- if it does happen there is a bug in the block layer for
requesting larger than dm_merge_bvec()'s initial response for a given
offset. Also, update a comment in dm_merge_bvec() relative to
max_hw_sectors_kb. And fix empty newline whitespace.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Allows for filesystems to submit bios that are a factor of the thinp
blocksize, improving dm-thinp efficiency (particularly when the data
volume is RAID).
Also set io_min to max_sectors_kb if it is a factor of the thinp
blocksize.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Throttle IO based on the time it's taking the worker to do one loop.
There were reports of hung task timeouts occuring and it was observed
that the excessively long avgqu-sz (as reported by iostat) was
contributing to these hung tasks.
Throttling definitely helps dm-thinp perform better under heavy IO load
(without being detremental by being overzealous). It reduces avgqu-sz
drastically, e.g.: from 60K to ~6K, and even as low as 150 once metadata
is cached by bufio, when dirty_ratio=5, dirty_background_ratio=2. And
avgqu-sz stays at or below 30K even with dirty_ratio=20,
dirty_background_ratio=10.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Prefetch metadata at the start of the worker thread and then again every
128th bio processed from the deferred list.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Introduce the dm_tm_issue_prefetches interface. If you're using a
non-blocking clone the tm will build up a list of requested blocks that
weren't in core. dm_tm_issue_prefetches will request those blocks to be
prefetched.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This change is a prerequisite for allowing metadata to be prefetched.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Previously it was using a fixed sized hash table. There are times
when very many concurrent cells are held (such as when processing a very
large discard). When this happens the hash table performance becomes
very poor.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
These changes help keep metadata backed by dm-bufio in-core longer which
fixes reports of metadata churn in the face of heavy random IO workloads.
Before, bufio evicted all buffers older than DM_BUFIO_DEFAULT_AGE_SECS.
Having a device (e.g. dm-thinp or dm-cache) lose all metadata just
because associated buffers had been idle for some time is unfriendly.
Now, the user may now configure the number of bytes that bufio retains
using the 'retain_bytes' module parameter. The default is 256K.
Also, the DM_BUFIO_WORK_TIMER_SECS and DM_BUFIO_DEFAULT_AGE_SECS
defaults were quite low so increase them (to 30 and 300 respectively).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Converting over to using an rbtree eliminates a fixed 8MB allocation
from vmalloc space for the hash table.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The walk code was using a 'ro_spine' to hold it's locked btree nodes.
But this data structure is designed for the rolling lock scheme, and
as such automatically unlocks blocks that are two steps up the call
chain. This is not suitable for the simple recursive walk algorithm,
which retraces its steps.
This code is only used by the persistent array code, which in turn is
only used by dm-cache. In order to trigger it you need to have a
mapping tree that is more than 2 levels deep; which equates to 8-16
million cache blocks. For instance a 4T ssd with a very small block
size of 32k only just triggers this bug.
The fix just places the locked blocks on the stack, and stops using
the ro_spine altogether.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Avoids normal IO racing with discard.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Commit 48cf06bc5f ("dm raid: add discard support for RAID levels 4, 5
and 6") did not properly handle missing metadata device(s). A failing
read of the superblock causes the metadata and data devices to be
removed from the dev array in struct raid_set, setting references to
both devices to NULL. configure_discard_support() nonetheless tries to
access the data dev unconditionally causing an oops.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The dm-raid superblock (struct dm_raid_superblock) is padded to 512
bytes and that size is being used to read it in from the metadata
device into one preallocated page.
Reading or writing this on a 512-byte sector device works fine but on
a 4096-byte sector device this fails.
Set the dm-raid superblock's size to the logical block size of the
metadata device, because IO at that size is guaranteed too work. Also
add a size check to avoid silent partial metadata loss in case the
superblock should ever grow past the logical block size or PAGE_SIZE.
[includes pointer math fix from Dan Carpenter]
Reported-by: "Liuhua Wang" <lwang@suse.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
The shrinker uses gfp flags to indicate what kind of operation can the
driver wait for. If __GFP_IO flag is present, the driver can wait for
block I/O operations, if __GFP_FS flag is present, the driver can wait on
operations involving the filesystem.
dm-bufio tested for __GFP_IO. However, dm-bufio can run on a loop block
device that makes calls into the filesystem. If __GFP_IO is present and
__GFP_FS isn't, dm-bufio could still block on filesystem operations if it
runs on a loop block device.
The change from __GFP_IO to __GFP_FS supposedly fixes one observed (though
unreproducible) deadlock involving dm-bufio and loop device.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Fix a potential struct stripe_c leak that would occur if the
chunk_size exceeded the maximum allowed by dm_set_target_max_io_len
(UINT_MAX). However, in practice there is no possibility of this
occuring given that chunk_size is of type uint32_t. But it is good to
fix this to future-proof in case dm_set_target_max_io_len's
implementation were to change.
Signed-off-by: Pavitra Kumar <pavitrak@nvidia.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If cn_add_callback() fails in dm_ulog_tfr_init(), it does not
deallocate prealloced memory but calls cn_del_callback().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
When __scan frees the required number of buffer entries that the
shrinker requested (nr_to_scan becomes zero) it must return. Before
this fix the __scan code exited only the inner loop and continued in the
outer loop -- which could result in reduced performance due to extra
buffers being freed (e.g. unnecessarily evicted thinp metadata needing
to be synchronously re-read into bufio's cache).
Also, move dm_bufio_cond_resched to __scan's inner loop, so that
iterating the bufio client's lru lists doesn't result in scheduling
latency.
Reported-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.2+
The 'last_accessed' member of the dm_buffer structure was only set when
the the buffer was created. This led to each buffer being discarded
after dm_bufio_max_age time even if it was used recently. In practice
this resulted in all thinp metadata being evicted soon after being read
-- this is particularly problematic for metadata intensive workloads
like multithreaded small random IO.
'last_accessed' is now updated each time the buffer is moved to the head
of the LRU list, so the buffer is now properly discarded if it was not
used in dm_bufio_max_age time.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.2+
In case of RAID levels 4, 5 and 6 we have to verify each RAID members'
ability to zero data on discards to avoid stripe data corruption -- if
discard_zeroes_data is not set for each RAID member discard support must
be disabled. But given the uncertainty of whether or not a RAID member
properly supports zeroing data on discard we require the user to
explicitly allow discard support on RAID levels 4, 5, and 6 by setting
a dm-raid module paramter, e.g.: dm-raid.devices_handle_discard_safely=Y
Otherwise, discards could cause data corruption on RAID4/5/6.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Discard support is not enabled for RAID levels 4, 5, and 6 at this time
due to concerns about unreliable discard_zeroes_data support on some
hardware. Otherwise, discards could cause stripe data corruption
(classic example of bad apples spoiling the bunch).
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Until this change, when loading a new DM table, DM core would re-open
all of the devices in the DM table. Now, DM core will avoid redundant
device opens (and closes when destroying the old table) if the old
table already has a device open using the same mode. This is achieved
by managing reference counts on the table_devices that DM core now
stores in the mapped_device structure (rather than in the dm_table
structure). So a mapped_device's active and inactive dm_tables' dm_dev
lists now just point to the dm_devs stored in the mapped_device's
table_devices list.
This improvement in DM core's device reference counting has the
side-effect of fixing a long-standing limitation of the multipath
target: a DM multipath table couldn't include any paths that were unusable
(failed). For example: if all paths have failed and you add a new,
working, path to the table; you can't use it since the table load would
fail due to it still containing failed paths. Now a re-load of a
multipath table can include failed devices and when those devices become
active again they can be used instantly.
The device list code in dm.c isn't a straight copy/paste from the code in
dm-table.c, but it's very close (aside from some variable renames). One
subtle difference is that find_table_device for the tables_devices list
will only match devices with the same name and mode. This is because we
don't want to upgrade a device's mode in the active table when an
inactive table is loaded.
Access to the mapped_device structure's tables_devices list requires a
mutex (tables_devices_lock), so that tables cannot be created and
destroyed concurrently.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
'queue_io' is set so that IO is queued while paths are being
initialized. Clear queue_io in __choose_pgpath if there are no valid
paths, since there are obviously no paths that can be initialized.
Otherwise IOs to the device will back up.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Since DM core uses bio_clone_fast() for both bio-based and request-based
DM devices there is no need for DM's bioset to have a bvec mempool.
With this patch, on arch with 4KB page for example, memory usage will be
reduced by 64KB for each bio-based DM device and 1MB for each
request-based DM device.
For example, when you create 10,000 bio-based DM devices and 1,000
request-based DM devices, memory usage of biovec under no load is:
# grep biovec /proc/slabinfo
biovec-256 418068 418068 4096 ...
biovec-128 0 0 2048 ...
biovec-64 0 0 1024 ...
biovec-16 0 0 256 ...
With this patch series applied, the usage becomes:
# grep biovec /proc/slabinfo
biovec-256 116 116 4096 ...
biovec-128 0 0 2048 ...
biovec-64 0 0 1024 ...
biovec-16 0 0 256 ...
So 4096 * (418068 - 116) = 1.6GB of memory is saved in this example.
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
alloc_tio() uses bio_alloc_bioset() to allocate a clone-bio for a bio.
alloc_tio() takes the number of bvecs to allocate for the clone-bio.
However, with v3.14's immutable biovec changes DM now uses
__bio_clone_fast() and no longer needs to allocate bvecs.
In practice, the 'nr_iovecs' passed to alloc_tio() is always effectively
0. __clone_and_map_simple_bio() looked like it was passing non-zero
nr_iovecs, but its value was always within the range of inline bvecs and
no allocation actually happened. If allocation happened, the BUG_ON() in
__bio_clone_fast() would've triggered.
Remove the nr_iovecs parameter from alloc_tio() to prevent possible
future bio_alloc_bioset() mis-use of a new bioset interface that will no
longer allow bvecs to be allocated.
Also fix extra whitespace before the __bio_clone_fast() call in
__clone_and_map_simple_bio().
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When a writeback or a promotion of a block is completed, the cell of
that block is removed from the prison, the block is marked as clean, and
the clear_dirty() callback of the cache policy is called.
Unfortunately, performing those actions in this order allows an incoming
new write bio for that block to come in before clearing the dirty status
is completed and therefore possibly causing one of these two scenarios:
Scenario A:
Thread 1 Thread 2
cell_defer() .
- cell removed from prison .
- detained bios queued .
. incoming write bio
. remapped to cache
. set_dirty() called,
. but block already dirty
. => it does nothing
clear_dirty() .
- block marked clean .
- policy clear_dirty() called .
Result: Block is marked clean even though it is actually dirty. No
writeback will occur.
Scenario B:
Thread 1 Thread 2
cell_defer() .
- cell removed from prison .
- detained bios queued .
clear_dirty() .
- block marked clean .
. incoming write bio
. remapped to cache
. set_dirty() called
. - block marked dirty
. - policy set_dirty() called
- policy clear_dirty() called .
Result: Block is properly marked as dirty, but policy thinks it is clean
and therefore never asks us to writeback it.
This case is visible in "dmsetup status" dirty block count (which
normally decreases to 0 on a quiet device).
Fix these issues by calling clear_dirty() before calling cell_defer().
Incoming bios for that block will then be detained in the cell and
released only after clear_dirty() has completed, so the race will not
occur.
Found by inspecting the code after noticing spurious dirty counts
(scenario B).
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
The DM crypt target accesses memory beyond allocated space resulting in
a crash on 32 bit x86 systems.
This bug is very old (it dates back to 2.6.25 commit 3a7f6c990a "dm
crypt: use async crypto"). However, this bug was masked by the fact
that kmalloc rounds the size up to the next power of two. This bug
wasn't exposed until 3.17-rc1 commit 298a9fa08a ("dm crypt: use per-bio
data"). By switching to using per-bio data there was no longer any
padding beyond the end of a dm-crypt allocated memory block.
To minimize allocation overhead dm-crypt puts several structures into one
block allocated with kmalloc. The block holds struct ablkcipher_request,
cipher-specific scratch pad (crypto_ablkcipher_reqsize(any_tfm(cc))),
struct dm_crypt_request and an initialization vector.
The variable dmreq_start is set to offset of struct dm_crypt_request
within this memory block. dm-crypt allocates the block with this size:
cc->dmreq_start + sizeof(struct dm_crypt_request) + cc->iv_size.
When accessing the initialization vector, dm-crypt uses the function
iv_of_dmreq, which performs this calculation: ALIGN((unsigned long)(dmreq
+ 1), crypto_ablkcipher_alignmask(any_tfm(cc)) + 1).
dm-crypt allocated "cc->iv_size" bytes beyond the end of dm_crypt_request
structure. However, when dm-crypt accesses the initialization vector, it
takes a pointer to the end of dm_crypt_request, aligns it, and then uses
it as the initialization vector. If the end of dm_crypt_request is not
aligned on a crypto_ablkcipher_alignmask(any_tfm(cc)) boundary the
alignment causes the initialization vector to point beyond the allocated
space.
Fix this bug by calculating the variable iv_size_padding and adding it
to the allocated size.
Also correct the alignment of dm_crypt_request. struct dm_crypt_request
is specific to dm-crypt (it isn't used by the crypto subsystem at all),
so it is aligned on __alignof__(struct dm_crypt_request).
Also align per_bio_data_size on ARCH_KMALLOC_MINALIGN, so that it is
aligned as if the block was allocated with kmalloc.
Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Most places which allocate an r10_bio zero the ->state, some don't.
As the r10_bio comes from a mempool, and the allocation function uses
kzalloc it is often zero anyway. But sometimes it isn't and it is
best to be safe.
I only noticed this because of the bug fixed by an earlier patch
where the r10_bios allocated for a reshape were left around to
be used by a subsequent resync. In that case the R10BIO_IsReshape
flag caused problems.
Signed-off-by: NeilBrown <neilb@suse.de>
When a raid10 commences a resync/recovery/reshape it allocates
some buffer space.
When a resync/recovery completes the buffer space is freed. But not
when the reshape completes.
This can result in a small memory leak.
There is a subtle side-effect of this bug. When a RAID10 is reshaped
to a larger array (more devices), the reshape is immediately followed
by a "resync" of the new space. This "resync" will use the buffer
space which was allocated for "reshape". This can cause problems
including a "BUG" in the SCSI layer. So this is suitable for -stable.
Cc: stable@vger.kernel.org (v3.5+)
Fixes: 3ea7daa5d7
Signed-off-by: NeilBrown <neilb@suse.de>
raid10 reshape clears unwanted bits from a bio->bi_flags using
a method which, while clumsy, worked until 3.10 when BIO_OWNS_VEC
was added.
Since then it clears that bit but shouldn't. This results in a
memory leak.
So change to used the approved method of clearing unwanted bits.
As this causes a memory leak which can consume all of memory
the fix is suitable for -stable.
Fixes: a38352e0ac
Cc: stable@vger.kernel.org (v3.10+)
Reported-by: mdraid.pkoch@dfgh.net (Peter Koch)
Signed-off-by: NeilBrown <neilb@suse.de>
During recovery of a double-degraded RAID6 it is possible for
some blocks not to be recovered properly, leading to corruption.
If a write happens to one block in a stripe that would be written to a
missing device, and at the same time that stripe is recovering data
to the other missing device, then that recovered data may not be written.
This patch skips, in the double-degraded case, an optimisation that is
only safe for single-degraded arrays.
Bug was introduced in 2.6.32 and fix is suitable for any kernel since
then. In an older kernel with separate handle_stripe5() and
handle_stripe6() functions the patch must change handle_stripe6().
Cc: stable@vger.kernel.org (2.6.32+)
Fixes: 6c0069c0ae
Cc: Yuri Tikhonov <yur@emcraft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: "Manibalan P" <pmanibalan@amiindia.co.in>
Tested-by: "Manibalan P" <pmanibalan@amiindia.co.in>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1090423
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
If a stripe in a raid6 array received a write to each data block while
the array is degraded, and if any of these writes to a missing device
are not page-aligned, then a live-lock happens.
In this case the P and Q blocks need to be read so that the part of
the missing block which is *not* being updated by the write can be
constructed. Due to a logic error, these blocks are not loaded, so
the update cannot proceed and the stripe is 'handled' repeatedly in an
infinite loop.
This bug is unlikely as most writes are page aligned. However as it
can lead to a livelock it is suitable for -stable. It was introduced
in 3.16.
Cc: stable@vger.kernel.org (v3.16)
Fixed: 67f455486d
Signed-off-by: NeilBrown <neilb@suse.de>
allow thin snapshots to be larger than the external origin.
. Add support for quickly loading a repetitive pattern into the
dm-switch target.
. Use per-bio data in the dm-crypt target instead of always using a
mempool for each allocation. Required switching to kmalloc alignment
for the bio slab.
. Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag
. Fix the dm-cache and dm-thin targets' export of the minimum_io_size to
match the data block size -- this fixes an issue where mkfs.xfs would
improperly infer raid striping was in place on the underlying storage.
. Small cleanups in dm-io, dm-mpath and dm-cache
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Merge tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper changes from Mike Snitzer:
- Allow the thin target to paired with any size external origin; also
allow thin snapshots to be larger than the external origin.
- Add support for quickly loading a repetitive pattern into the
dm-switch target.
- Use per-bio data in the dm-crypt target instead of always using a
mempool for each allocation. Required switching to kmalloc alignment
for the bio slab.
- Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag
- Fix the dm-cache and dm-thin targets' export of the minimum_io_size
to match the data block size -- this fixes an issue where mkfs.xfs
would improperly infer raid striping was in place on the underlying
storage.
- Small cleanups in dm-io, dm-mpath and dm-cache
* tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm table: propagate QUEUE_FLAG_NO_SG_MERGE
dm switch: efficiently support repetitive patterns
dm switch: factor out switch_region_table_read
dm cache: set minimum_io_size to cache's data block size
dm thin: set minimum_io_size to pool's data block size
dm crypt: use per-bio data
block: use kmalloc alignment for bio slab
dm table: make dm_table_supports_discards static
dm cache metadata: use dm-space-map-metadata.h defined size limits
dm cache: fail migrations in the do_worker error path
dm cache: simplify deferred set reference count increments
dm thin: relax external origin size constraints
dm thin: switch to an atomic_t for tracking pending new block preparations
dm mpath: eliminate pg_ready() wrapper
dm io: simplify dec_count and sync_io
Pull block driver changes from Jens Axboe:
"Nothing out of the ordinary here, this pull request contains:
- A big round of fixes for bcache from Kent Overstreet, Slava Pestov,
and Surbhi Palande. No new features, just a lot of fixes.
- The usual round of drbd updates from Andreas Gruenbacher, Lars
Ellenberg, and Philipp Reisner.
- virtio_blk was converted to blk-mq back in 3.13, but now Ming Lei
has taken it one step further and added support for actually using
more than one queue.
- Addition of an explicit SG_FLAG_Q_AT_HEAD for block/bsg, to
compliment the the default behavior of adding to the tail of the
queue. From Douglas Gilbert"
* 'for-3.17/drivers' of git://git.kernel.dk/linux-block: (86 commits)
bcache: Drop unneeded blk_sync_queue() calls
bcache: add mutex lock for bch_is_open
bcache: Correct printing of btree_gc_max_duration_ms
bcache: try to set b->parent properly
bcache: fix memory corruption in init error path
bcache: fix crash with incomplete cache set
bcache: Fix more early shutdown bugs
bcache: fix use-after-free in btree_gc_coalesce()
bcache: Fix an infinite loop in journal replay
bcache: fix crash in bcache_btree_node_alloc_fail tracepoint
bcache: bcache_write tracepoint was crashing
bcache: fix typo in bch_bkey_equal_header
bcache: Allocate bounce buffers with GFP_NOWAIT
bcache: Make sure to pass GFP_WAIT to mempool_alloc()
bcache: fix uninterruptible sleep in writeback thread
bcache: wait for buckets when allocating new btree root
bcache: fix crash on shutdown in passthrough mode
bcache: fix lockdep warnings on shutdown
bcache allocator: send discards with correct size
bcache: Fix to remove the rcu_sched stalls.
...
Most interesting is that md devices (major == 9) with
minor numbers of 512 or more will no longer be created
simply by opening a block device file. They can only
be created by writing to
/sys/module/md_mod/parameters/new_array
The 'auto-create-on-open' semantic is cumbersome and we
need to start moving away from it.
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Merge tag 'md/3.17' of git://neil.brown.name/md
Pull md updates from Neil Brown:
"Most interesting is that md devices (major == 9) with minor numbers of
512 or more will no longer be created simply by opening a block device
file. They can only be created by writing to
/sys/module/md_mod/parameters/new_array
The 'auto-create-on-open' semantic is cumbersome and we need to start
moving away from it"
* tag 'md/3.17' of git://neil.brown.name/md:
md: don't allow bitmap file to be added to raid0/linear.
md/raid0: check for bitmap compatability when changing raid levels.
md: Recovery speed is wrong
md: disable probing for md devices 512 and over.
md/raid1,raid10: always abort recover on write error.
