As described in commit 8111964f1b ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata"), ABBA deadlocks will be
triggered because shrinker_rwsem currently needs to held by
dm_pool_abort_metadata() as a side-effect of thin-pool metadata
operation failure.
The following three problem scenarios have been noticed:
1) Described by commit 8111964f1b ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata")
2) shrinker_rwsem and throttle->lock
P1(drop cache) P2(kworker)
drop_caches_sysctl_handler
drop_slab
shrink_slab
down_read(&shrinker_rwsem) - LOCK A
do_shrink_slab
super_cache_scan
prune_icache_sb
dispose_list
evict
ext4_evict_inode
ext4_clear_inode
ext4_discard_preallocations
ext4_mb_load_buddy_gfp
ext4_mb_init_cache
ext4_wait_block_bitmap
__ext4_error
ext4_handle_error
ext4_commit_super
...
dm_submit_bio
do_worker
throttle_work_update
down_write(&t->lock) -- LOCK B
process_deferred_bios
commit
metadata_operation_failed
dm_pool_abort_metadata
dm_block_manager_create
dm_bufio_client_create
register_shrinker
down_write(&shrinker_rwsem)
-- LOCK A
thin_map
thin_bio_map
thin_defer_bio_with_throttle
throttle_lock
down_read(&t->lock) - LOCK B
3) shrinker_rwsem and wait_on_buffer
P1(drop cache) P2(kworker)
drop_caches_sysctl_handler
drop_slab
shrink_slab
down_read(&shrinker_rwsem) - LOCK A
do_shrink_slab
...
ext4_wait_block_bitmap
__ext4_error
ext4_handle_error
jbd2_journal_abort
jbd2_journal_update_sb_errno
jbd2_write_superblock
submit_bh
// LOCK B
// RELEASE B
do_worker
throttle_work_update
down_write(&t->lock) - LOCK B
process_deferred_bios
process_bio
commit
metadata_operation_failed
dm_pool_abort_metadata
dm_block_manager_create
dm_bufio_client_create
register_shrinker
register_shrinker_prepared
down_write(&shrinker_rwsem) - LOCK A
bio_endio
wait_on_buffer
__wait_on_buffer
Fix these by resetting dm_bufio_client without holding shrinker_rwsem.
Fixes: 8111964f1b ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata")
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.
Suggested-by: John Wiele <jwiele@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Add a flags argument to dm_bufio_client_create and update all the
callers. This is in preparation to add the DM_BUFIO_NO_SLEEP flag.
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap().
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Abuse of BUG_ON() is never appropriate, best to propagate errors to
fail gracefully (rather than take the entire system down).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Should have been removed as part of commit f73e2e70ec ("dm btree
spine: remove paranoid node_check call in node_prep_for_write()")
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Move dm_tm_unlock() after dm_tm_dec().
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
remove_raw() in dm_btree_remove() may fail due to IO read error
(e.g. read the content of origin block fails during shadowing),
and the value of shadow_spine::root is uninitialized, but
the uninitialized value is still assign to new_root in the
end of dm_btree_remove().
For dm-thin, the value of pmd->details_root or pmd->root will become
an uninitialized value, so if trying to read details_info tree again
out-of-bound memory may occur as showed below:
general protection fault, probably for non-canonical address 0x3fdcb14c8d7520
CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6
Hardware name: QEMU Standard PC
RIP: 0010:metadata_ll_load_ie+0x14/0x30
Call Trace:
sm_metadata_count_is_more_than_one+0xb9/0xe0
dm_tm_shadow_block+0x52/0x1c0
shadow_step+0x59/0xf0
remove_raw+0xb2/0x170
dm_btree_remove+0xf4/0x1c0
dm_pool_delete_thin_device+0xc3/0x140
pool_message+0x218/0x2b0
target_message+0x251/0x290
ctl_ioctl+0x1c4/0x4d0
dm_ctl_ioctl+0xe/0x20
__x64_sys_ioctl+0x7b/0xb0
do_syscall_64+0x40/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fixing it by only assign new_root when removal succeeds
Signed-off-by: Hou Tao <houtao1@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The disk space map stores it's index entries in a btree, these are
accessed very frequently, so having a few cached makes a big difference
to performance.
With this change provisioning a new block takes roughly 20% less cpu.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When we break sharing on btree nodes we typically need to increment
the reference counts to every value held in the node. This can
cause a lot of repeated calls to the space maps. Fix this by changing
the interface to the space map inc/dec methods to take ranges of
adjacent blocks to be operated on.
For installations that are using a lot of snapshots this will reduce
cpu overhead of fundamental operations such as provisioning a new block,
or deleting a snapshot, by as much as 10 times.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Current commit code resets the place where the search for free blocks
will begin back to the start of the metadata device. There are a couple
of repercussions to this:
- The first allocation after the commit is likely to take longer than
normal as it searches for a free block in an area that is likely to
have very few free blocks (if any).
- Any free blocks it finds will have been recently freed. Reusing them
means we have fewer old copies of the metadata to aid recovery from
hardware error.
Fix these issues by leaving the cursor alone, only resetting when the
search hits the end of the metadata device.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit improves the residency of btrees built in the metadata for
dm-thin and dm-cache.
When inserting a new entry into a full btree node the current code
splits the node into two. This can result in very many half full nodes,
particularly if the insertions are occurring in an ascending order (as
happens in dm-thin with large writes).
With this commit, when we insert into a full node we first try and move
some entries to a neighbouring node that has space, failing that it
tries to split two neighbouring nodes into three.
Results are given below. 'Residency' is how full nodes are on average
as a percentage. Average instruction counts for the operations
are given to show the extra processing has little overhead.
+--------------------------+--------------------------+
| Before | After |
+------------+-----------+-----------+--------------+-----------+--------------+
| Test | Phase | Residency | Instructions | Residency | Instructions |
+------------+-----------+-----------+--------------+-----------+--------------+
| Ascending | insert | 50 | 1876 | 96 | 1930 |
| | overwrite | 50 | 1789 | 96 | 1746 |
| | lookup | 50 | 778 | 96 | 778 |
| Descending | insert | 50 | 3024 | 96 | 3181 |
| | overwrite | 50 | 1789 | 96 | 1746 |
| | lookup | 50 | 778 | 96 | 778 |
| Random | insert | 68 | 3800 | 84 | 3736 |
| | overwrite | 68 | 4254 | 84 | 3911 |
| | lookup | 68 | 779 | 84 | 779 |
| Runs | insert | 63 | 2546 | 82 | 2815 |
| | overwrite | 63 | 2013 | 82 | 1986 |
| | lookup | 63 | 778 | 82 | 779 |
+------------+-----------+-----------+--------------+-----------+--------------+
Ascending - keys are inserted in ascending order.
Descending - keys are inserted in descending order.
Random - keys are inserted in random order.
Runs - keys are split into ascending runs of ~20 length. Then
the runs are shuffled.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com> # contains_key() fix
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This division bug meant the search for free metadata space could skip
the final allocation bitmap's worth of entries. Fix affects DM thinp,
cache and era targets.
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Tested-by: Ming-Hung Tsai <mtsai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Otherwise most non-x86 architectures (e.g. riscv, arm) will resort to
byte-by-byte access.
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Remove this extra BUG_ON() that calls node_check() -- which avoids extra crc checking.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Both sm_disk_new_block and sm_disk_commit are needlessly calling
sm_disk_get_nr_free(). Looks like old queries used for some
debugging.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
shadow_root() truncates 64-bit dm_block_t into 32-bit int. This is
not an issue in practice, since dm metadata as of v5.11 can only hold at
most 4161600 blocks (255 index entries * ~16k metadata blocks).
Nevertheless, this can confuse users debugging some specific data
corruption scenarios. Also, DM_SM_METADATA_MAX_BLOCKS may be bumped in
the future, or persistent-data may find its use in other places.
Therefore, switch the return type of shadow_root from int to dm_block_t.
Signed-off-by: Jinoh Kang <jinoh.kang.kr@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The local variable disk details is not used during the creating of thin & snap
devices. Remove them from dm-thin-metadata, and add pointer validity check for
pointer value in btree_lookup_raw. Skip memory copy when the caller doesn't need
the value.
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The following error ocurred when testing disk online/offline:
[ 301.798344] device-mapper: thin: 253:5: aborting current metadata transaction
[ 301.848441] device-mapper: thin: 253:5: failed to abort metadata transaction
[ 301.849206] Aborting journal on device dm-26-8.
[ 301.850489] EXT4-fs error (device dm-26) in __ext4_new_inode:943: Journal has aborted
[ 301.851095] EXT4-fs (dm-26): Delayed block allocation failed for inode 398742 at logical offset 181 with max blocks 19 with error 30
[ 301.854476] BUG: KASAN: use-after-free in dm_bm_set_read_only+0x3a/0x40 [dm_persistent_data]
Reason is:
metadata_operation_failed
abort_transaction
dm_pool_abort_metadata
__create_persistent_data_objects
r = __open_or_format_metadata
if (r) --> If failed will free pmd->bm but pmd->bm not set NULL
dm_block_manager_destroy(pmd->bm);
set_pool_mode
dm_pool_metadata_read_only(pool->pmd);
dm_bm_set_read_only(pmd->bm); --> use-after-free
Add checks to see if pmd->bm is NULL in dm_bm_set_read_only and
dm_bm_set_read_write functions. If bm is NULL it means creating the
bm failed and so dm_bm_is_read_only must return true.
Signed-off-by: Ye Bin <yebin10@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.
This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.
There are a variety of indentation styles found.
a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'
In order to convert all of them to 1 tab + 'help', I ran the
following commend:
$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In commit 4c7da06f5a ("dm persistent data: eliminate unnecessary
return values"), r value in exit_ro_spine will not change, so
exit_ro_spine doesn't need a return value.
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The space-maps track the reference counts for disk blocks allocated by
both the thin-provisioning and cache targets. There are variants for
tracking metadata blocks and data blocks.
Transactionality is implemented by never touching blocks from the
previous transaction, so we can rollback in the event of a crash.
When allocating a new block we need to ensure the block is free (has
reference count of 0) in both the current and previous transaction.
Prior to this fix we were doing this by searching for a free block in
the previous transaction, and relying on a 'begin' counter to track
where the last allocation in the current transaction was. This
'begin' field was not being updated in all code paths (eg, increment
of a data block reference count due to breaking sharing of a neighbour
block in the same btree leaf).
This fix keeps the 'begin' field, but now it's just a hint to speed up
the search. Instead the current transaction is searched for a free
block, and then the old transaction is double checked to ensure it's
free. Much simpler.
This fixes reports of sm_disk_new_block()'s BUG_ON() triggering when
DM thin-provisioning's snapshots are heavily used.
Reported-by: Eric Wheeler <dm-devel@lists.ewheeler.net>
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
We got the following warnings from thin_check during thin-pool setup:
$ thin_check /dev/vdb
examining superblock
examining devices tree
missing devices: [1, 84]
too few entries in btree_node: 41, expected at least 42 (block 138, max_entries = 126)
examining mapping tree
The phenomenon is the number of entries in one node of details_info tree is
less than (max_entries / 3). And it can be easily reproduced by the following
procedures:
$ new a thin pool
$ presume the max entries of details_info tree is 126
$ new 127 thin devices (e.g. 1~127) to make the root node being full
and then split
$ remove the first 43 (e.g. 1~43) thin devices to make the children
reblance repeatedly
$ stop the thin pool
$ thin_check
The root cause is that the B-tree removal procedure in __rebalance2()
doesn't guarantee the invariance: the minimal number of entries in
non-root node should be >= (max_entries / 3).
Simply fix the problem by increasing the rebalance threshold to
make sure the number of entries in each child will be greater
than or equal to (max_entries / 3 + 1), so no matter which
child is used for removal, the number will still be valid.
Cc: stable@vger.kernel.org
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The function sm_find_free() just returns -ENOSPC and 0.
So remove lone caller's check for some other error.
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In commit 6096d91af0 ("dm space map metadata: fix occasional leak
of a metadata block on resize"), we refactor the commit logic to a new
function 'apply_bops'. But when that logic was replaced in out() the
return value was not stored. This may lead out() returning a wrong
value to the caller.
Fixes: 6096d91af0 ("dm space map metadata: fix occasional leak of a metadata block on resize")
Cc: stable@vger.kernel.org
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When btree_split_beneath() splits a node to two new children, it will
allocate two blocks: left and right. If right block's allocation
failed, the left block will be unlocked and marked dirty. If this
happened, the left block'ss content is zero, because it wasn't
initialized with the btree struct before the attempot to allocate the
right block. Upon return, when flushing the left block to disk, the
validator will fail when check this block. Then a BUG_ON is raised.
Fix this by completely initializing the left block before allocating and
initializing the right block.
Fixes: 4dcb8b57df ("dm btree: fix leak of bufio-backed block in btree_split_beneath error path")
Cc: stable@vger.kernel.org
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
locking. Requires some list_bl interface improvements.
- Add ability for DM integrity to use a bitmap mode, that tracks regions
where data and metadata are out of sync, instead of using a journal.
- Improve DM thin provisioning target to not write metadata changes to
disk if the thin-pool and associated thin devices are merely
activated but not used. This avoids metadata corruption due to
concurrent activation of thin devices across different OS instances
(e.g. split brain scenarios, which ultimately would be avoided if
proper device filters were used -- but not having proper filtering has
proven a very common configuration mistake)
- Fix missing call to path selector type->end_io in DM multipath. This
fixes reported performance problems due to inaccurate path selector IO
accounting causing an imbalance of IO (e.g. avoiding issuing IO to
particular path due to it seemingly being heavily used).
- Fix bug in DM cache metadata's loading of its discard bitset that
could lead to all cache blocks being discarded if the very first cache
block was discarded (thankfully in practice the first cache block is
generally in use; be it FS superblock, partition table, disk label,
etc).
- Add testing-only DM dust target which simulates a device that has
failing sectors and/or read failures.
- Fix a DM init error path reference count hang that caused boot hangs
if user supplied malformed input on kernel commandline.
- Fix a couple issues with DM crypt target's logging being overly
verbose or lacking context.
- Various other small fixes to DM init, DM multipath, DM zoned, and DM
crypt.
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Merge tag 'for-5.2/dm-changes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- Improve DM snapshot target's scalability by using finer grained
locking. Requires some list_bl interface improvements.
- Add ability for DM integrity to use a bitmap mode, that tracks
regions where data and metadata are out of sync, instead of using a
journal.
- Improve DM thin provisioning target to not write metadata changes to
disk if the thin-pool and associated thin devices are merely
activated but not used. This avoids metadata corruption due to
concurrent activation of thin devices across different OS instances
(e.g. split brain scenarios, which ultimately would be avoided if
proper device filters were used -- but not having proper filtering
has proven a very common configuration mistake)
- Fix missing call to path selector type->end_io in DM multipath. This
fixes reported performance problems due to inaccurate path selector
IO accounting causing an imbalance of IO (e.g. avoiding issuing IO to
particular path due to it seemingly being heavily used).
- Fix bug in DM cache metadata's loading of its discard bitset that
could lead to all cache blocks being discarded if the very first
cache block was discarded (thankfully in practice the first cache
block is generally in use; be it FS superblock, partition table, disk
label, etc).
- Add testing-only DM dust target which simulates a device that has
failing sectors and/or read failures.
- Fix a DM init error path reference count hang that caused boot hangs
if user supplied malformed input on kernel commandline.
- Fix a couple issues with DM crypt target's logging being overly
verbose or lacking context.
- Various other small fixes to DM init, DM multipath, DM zoned, and DM
crypt.
* tag 'for-5.2/dm-changes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (42 commits)
dm: fix a couple brace coding style issues
dm crypt: print device name in integrity error message
dm crypt: move detailed message into debug level
dm ioctl: fix hang in early create error condition
dm integrity: whitespace, coding style and dead code cleanup
dm integrity: implement synchronous mode for reboot handling
dm integrity: handle machine reboot in bitmap mode
dm integrity: add a bitmap mode
dm integrity: introduce a function add_new_range_and_wait()
dm integrity: allow large ranges to be described
dm ingerity: pass size to dm_integrity_alloc_page_list()
dm integrity: introduce rw_journal_sectors()
dm integrity: update documentation
dm integrity: don't report unused options
dm integrity: don't check null pointer before kvfree and vfree
dm integrity: correctly calculate the size of metadata area
dm dust: Make dm_dust_init and dm_dust_exit static
dm dust: remove redundant unsigned comparison to less than zero
dm mpath: always free attached_handler_name in parse_path()
dm init: fix max devices/targets checks
...
Replace the indirection through struct stack_trace with an invocation of
the storage array based interface. This results in less storage space and
indirection.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094802.533968922@linutronix.de
Otherwise, memory that is allocated (and potentially not previously
zeroed) will get written to disk as part of the space maps.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
unlikely has already included in IS_ERR(),
so just remove redundant unlikely annotation.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.
On the other hand DM bitmap API is special case.
Adding 'dm' prefix to it to avoid potential name space collision.
No functional changes intended.
Suggested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Move dm-bufio.h to include/linux/ so that external GPL'd DM target
modules can use it.
It is better to allow the use of dm-bufio than force external modules
to implement the equivalent buffered IO mechanism in some new way. The
hope is this will encourage the use of dm-bufio; which will then make it
easier for a GPL'd external DM target module to be included upstream.
A couple dm-bufio EXPORT_SYMBOL exports have also been updated to use
EXPORT_SYMBOL_GPL.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
