Mike Snitzer [Thu, 2 Jun 2016 15:48:09 +0000 (11:48 -0400)]
dm raid: bump to v1.9.0 and make the extended SB feature flag reflect it
No idea what Heinz was doing with the versioning but upstream commit 4c9971ca6a ("dm raid: make sure no feature flags are set in metadata")
bumped to 1.8.0 already.
dm raid: enhance status interface and fixup takeover/raid0
The target's status interface has to provide the new 'data_offset' value
to allow userspace to retrieve the kernels offset to the data on each
raid device of a raid set. This is the base for out-of-place reshaping
required to not write over any data during reshaping (e.g. change
raid6_zr -> raid6_nc):
- add rs_set_cur() to be able to start up existing array in case of no
takeover; use in ctr on takeover check
- enhance raid_status()
- add supporting functions to get resync/reshape progress and raid
device status chars
- fixup rebuild table line output race, which does miss to emit
'rebuild N' on fully synced/rebuild devices, because it is relying on
the transient 'In_sync' raid device flag
- add new status line output for 'data_offset', which'll later be used
for out-of-place reshaping
- fixup takeover not working for all levels
- fixup raid0 message interface oops caused by missing checks
for the md threads, which don't exist in case of raid0
- remove ALL_FREEZE_FLAGS not needed for takeover
- adjust comments
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add raid level takeover support allowing arbitrary takeovers between
raid levels supported by md personalities (i.e. raid0, raid1/10 and
raid4/5/6):
- add rs_config_{backup|restore} function to allow for temporary
storing ctr requested layout changes and restore them for takeover
conersion decision after the superblocks got loaded and analyzed
- add members to store layout to 'struct raid_set' (not mandatory
for takeover but needed for reshape in later patch)
- add rebuild_disks bitfield to 'struct raid_set' and set bits in ctr
to use in setting up takeover (base to address a 'rebuild' related
raid_status() table line bug and needed as well for reshape in future
patch)
- add runtime flags and respective manipulation functions to be able to
control e.g. wrting of superlocks to the preresume function on
takeover and (later) reshape
- add functions to detect takeover, check it's valid (mandatory here to
avoid failing on md_run()), setup for it and use in the ctr; those
will be likely moved out once reshaping gets added to simplify the
ctr
- start raid set readonly in ctr and switch to readwrite, optionally
updating superblocks, in preresume in order to allow suspend to
quiesce any active table before (which involves superblock updates);
this ensures the proper sequence of writing the current and any new
takeover(/reshape) metadata
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm raid: introduce extended superblock and new raid types to support takeover/reshaping
Add new members to the dm-raid superblock and new raid types to support
takeover/reshape.
Add all necessary members needed to support takeover and reshape in one
go -- aiming to limit the amount of changes to the superblock layout.
This is a larger patch due to the new superblock members, their related
flags, validation of both and involved API additions/changes:
- add additional members to keep track of:
- state about forward/backward reshaping
- reshape position
- new level, layout, stripe size and delta disks
- data offset to current and new data for out-of-place reshapes
- failed devices bitfield extensions to keep track of max raid devices
- adjust super_validate() to cope with new superblock members
- adjust super_init_validation() to cope with new superblock members
- add definitions for ctr flags supporting delta disks etc.
- add new raid types (raid6_n_6 etc.)
- add new raid10 supporting function API (_is_raid10_*())
- adjust to changed raid10 supporting function API
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Mike Snitzer [Wed, 25 May 2016 01:16:51 +0000 (21:16 -0400)]
dm mpath: add optional "queue_mode" feature
Allow a user to specify an optional feature 'queue_mode <mode>' where
<mode> may be "bio", "rq" or "mq" -- which corresponds to bio-based,
request_fn rq-based, and blk-mq rq-based respectively.
If the queue_mode feature isn't specified the default for the
"multipath" target is still "rq" but if dm_mod.use_blk_mq is set to Y
it'll default to mode "mq".
This new queue_mode feature introduces the ability for each multipath
device to have its own queue_mode (whereas before this feature all
multipath devices effectively had to have the same queue_mode).
This commit also goes a long way to eliminate the awkward (ab)use of
DM_TYPE_*, the associated filter_md_type() and other relatively fragile
and difficult to maintain code.
Mike Snitzer [Thu, 19 May 2016 20:15:14 +0000 (16:15 -0400)]
dm mpath: reinstate bio-based support
Add "multipath-bio" target that offers a bio-based multipath target as
an alternative to the request-based "multipath" target -- but in a
following commit "multipath-bio" will immediately be replaced by a new
"queue_mode" feature for the "multipath" target which will allow
bio-based mode to be selected.
When DM multipath was originally converted from bio-based to
request-based the motivation for the change was better dynamic load
balancing (by leveraging block core's request-based IO schedulers, for
merging and sorting, _before_ DM multipath would make the decision on
where to steer the IO -- based on path load and/or availability).
More background is available in this "Request-based Device-mapper
multipath and Dynamic load balancing" paper:
https://www.kernel.org/doc/ols/2007/ols2007v2-pages-235-244.pdf
But we've now come full circle where significantly faster storage
devices no longer need IOs to be made larger to drive optimal IO
performance. And even if they do there have been changes to the block
and filesystem layers that help ensure upper layers are constructing
larger IOs. In addition, SCSI's differentiated IO errors will propagate
through to bio-based IO completion hooks -- so that eliminates another
historic justiciation for request-based DM multipath. Lastly, the block
layer's immutable biovec changes have made bio cloning cheaper than it
has ever been; whereas request cloning is still relatively expensive
(both on a CPU usage and memory footprint level).
As such, bio-based DM multipath offers the promise of a more efficient
IO path for high IOPs devices that are, or will be, emerging.
Mike Snitzer [Thu, 12 May 2016 20:28:10 +0000 (16:28 -0400)]
dm: move request-based code out to dm-rq.[hc]
Add some seperation between bio-based and request-based DM core code.
'struct mapped_device' and other DM core only structures and functions
have been moved to dm-core.h and all relevant DM core .c files have been
updated to include dm-core.h rather than dm.h
DM targets should _never_ include dm-core.h!
[block core merge conflict resolution from Stephen Rothwell] Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Jens Axboe [Thu, 9 Jun 2016 21:47:29 +0000 (15:47 -0600)]
cfq-iosched: temporarily boost queue priority for idle classes
If we're queuing REQ_PRIO IO and the task is running at an idle IO
class, then temporarily boost the priority. This prevents livelocks
due to priority inversion, when a low priority task is holding file
system resources while attempting to do IO.
An example of that is shown below. An ioniced idle task is holding
the directory mutex, while a normal priority task is trying to do
a directory lookup.
Ming Lei [Mon, 30 May 2016 13:34:35 +0000 (21:34 +0800)]
block: drbd: avoid to use BIO_MAX_SIZE
Use BIO_MAX_PAGES instead and we will remove BIO_MAX_SIZE.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Ming Lei [Thu, 9 Jun 2016 16:03:28 +0000 (10:03 -0600)]
block: bio: remove BIO_MAX_SECTORS
No one need this macro, so remove it. The motivation is for supporting
multipage bvecs, in which we only know what the max count of bvecs is
supported in the bio, instead of max size or max sectors.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Ming Lei [Mon, 30 May 2016 13:34:33 +0000 (21:34 +0800)]
fs: xfs: replace BIO_MAX_SECTORS with BIO_MAX_PAGES
BIO_MAX_PAGES is used as maximum count of bvecs, so
replace BIO_MAX_SECTORS with BIO_MAX_PAGES since
BIO_MAX_SECTORS is to be removed.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Ming Lei [Mon, 30 May 2016 13:34:32 +0000 (21:34 +0800)]
iov_iter: use bvec iterator to implement iterate_bvec()
bvec has one native/mature iterator for long time, so not
necessary to use the reinvented wheel for iterating bvecs
in lib/iov_iter.c.
Two ITER_BVEC test cases are run:
- xfstest(-g auto) on loop dio/aio, no regression found
- swap file works well under extreme stress(stress-ng --all 64 -t
800 -v), and lots of OOMs are triggerd, and the whole
system still survives
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Ming Lei [Mon, 30 May 2016 13:34:31 +0000 (21:34 +0800)]
block: mark 1st parameter of bvec_iter_advance as const
bvec_iter_advance() only writes the parameter of iterator,
so the base address of bvec can be marked as const safely.
Without the change, we can see compiling warning in the
following patch for implementing iterate_bvec(): lib/iov_iter.c
with bvec iterator.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Ming Lei [Mon, 30 May 2016 13:34:30 +0000 (21:34 +0800)]
block: move two bvec structure into bvec.h
This patch moves 'struct bio_vec' and 'struct bvec_iter'
into 'include/linux/bvec.h', then always include this header
into 'include/linux/blk_types.h'.
With this change, both 'struct bvec_iter' and bvec iterator
helpers don't depend on CONFIG_BLOCK any more, then we can
use bvec iterator to implement iterate_bvec(): lib/iov_iter.c.
Reviewed-by: Christoph Hellwig <hch@lst.de> Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Ming Lei [Thu, 9 Jun 2016 16:00:58 +0000 (10:00 -0600)]
block: move bvec iterator into include/linux/bvec.h
bvec iterator helpers should be used to implement by
iterate_bvec():lib/iov_iter.c too, and move them into
one header, so that we can keep bvec iterator header
out of CONFIG_BLOCK. Then we can remove the reinventing
of wheel in iterate_bvec().
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Omar Sandoval [Thu, 9 Jun 2016 01:22:20 +0000 (18:22 -0700)]
blk-mq: actually hook up defer list when running requests
If ->queue_rq() returns BLK_MQ_RQ_QUEUE_OK, we use continue and skip
over the rest of the loop body. However, dptr is assigned later in the
loop body, and the BLK_MQ_RQ_QUEUE_OK case is exactly the case that we'd
want it for.
NVMe isn't actually using BLK_MQ_F_DEFER_ISSUE yet, nor is any other
in-tree driver, but if the code's going to be there, it might as well
work.
Fixes: 74c450521dd8 ("blk-mq: add a 'list' parameter to ->queue_rq()") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Wed, 8 Jun 2016 20:49:40 +0000 (15:49 -0500)]
ext4: use bio op helprs in ext4 crypto code
This was missed from my last patchset.
This patch has ext4 crypto code use the bio op helper
to set the operation. The operation (discard, write, writesame,
etc) is now defined seperately from the other REQ bits. They
still share the bi_rw field to save space, so we use these
helpers so modules do not have to worry about setting/overwriting
info.
Jens, I am not sure how you handle patches on top of patches
in the next branches. If you merge patches that fix issues
in previous patches in next, then this patch could be part
of
Jeff Moyer [Wed, 8 Jun 2016 14:55:34 +0000 (08:55 -0600)]
cfq-iosched: Convert from jiffies to nanoseconds
Convert all time-keeping in CFQ IO scheduler from jiffies to nanoseconds
so that we can later make the intervals more fine-grained than jiffies.
One jiffie is several miliseconds and even for today's rotating disks
that is a noticeable amount of time and thus we leave disk unnecessarily
idle.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:25 +0000 (14:32 -0500)]
block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:24 +0000 (14:32 -0500)]
block: do not use REQ_FLUSH for tracking flush support
The last patch added a REQ_OP_FLUSH for request_fn drivers
and the next patch renames REQ_FLUSH to REQ_PREFLUSH which
will be used by file systems and make_request_fn drivers so
they can send a write/flush combo.
This patch drops xen's use of REQ_FLUSH to track if it supports
REQ_OP_FLUSH requests, so REQ_FLUSH can be deleted.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Juergen Gross <kernel@pfupf.net> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:23 +0000 (14:32 -0500)]
block, drivers: add REQ_OP_FLUSH operation
This adds a REQ_OP_FLUSH operation that is sent to request_fn
based drivers by the block layer's flush code, instead of
sending requests with the request->cmd_flags REQ_FLUSH bit set.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:22 +0000 (14:32 -0500)]
block, fs, drivers: remove REQ_OP compat defs and related code
This patch drops the compat definition of req_op where it matches
the rq_flag_bits definitions, and drops the related old and compat
code that allowed users to set either the op or flags for the operation.
We also then store the operation in the bi_rw/cmd_flags field similar
to how we used to store the bio ioprio where it sat in the upper bits
of the field.
Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:20 +0000 (14:32 -0500)]
block: move bio io prio to a new field
In the next patch, we move drop the compat code and make
the op a separate value that is hidden in bi_rw. To give
the op and rq bits flags room to grow this moves prio to
its own field.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:19 +0000 (14:32 -0500)]
ide cd: do not set REQ_WRITE on requests.
The block layer will set the correct READ/WRITE operation flags/fields
when creating a request, so there is not need for drivers to set the
REQ_WRITE flag.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:17 +0000 (14:32 -0500)]
drivers: use req op accessor
The req operation REQ_OP is separated from the rq_flag_bits
definition. This converts the block layer drivers to
use req_op to get the op from the request struct.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:14 +0000 (14:32 -0500)]
blkg_rwstat: separate op from flags
The bio and request operation and flags are going to be separate
definitions, so we cannot pass them in as a bitmap. This patch
converts the blkg_rwstat code and its caller, cfq, to pass in the
values separately.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:12 +0000 (14:32 -0500)]
block: prepare mq request creation to use REQ_OPs
This patch modifies the blk mq request creation code to use
separate variables for the operation and flags, because in the
the next patches the struct request users will be converted like
was done for bios.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:11 +0000 (14:32 -0500)]
block: prepare request creation/destruction code to use REQ_OPs
This patch prepares *_get_request/*_put_request and freed_request,
to use separate variables for the operation and flags. In the
next patches the struct request users will be converted like
was done for bios where the op and flags are set separately.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:32:03 +0000 (14:32 -0500)]
dm: pass dm stats data dir instead of bi_rw
It looks like dm stats cares about the data direction
(READ vs WRITE) and does not need the bio/request flags.
Commands like REQ_FLUSH, REQ_DISCARD and REQ_WRITE_SAME
are currently always set with REQ_WRITE, so the extra check for
REQ_DISCARD in dm_stats_account_io is not needed.
This patch has it use the bio and request data_dir helpers
instead of accessing the bi_rw/cmd_flags directly. This makes
the next patches that remove the operation from the cmd_flags
and bi_rw easier, because we will no longer have the REQ_WRITE
bit set for operations like discards.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:54 +0000 (14:31 -0500)]
btrfs: use bio fields for op and flags
The bio REQ_OP and bi_rw rq_flag_bits are now always setup, so there is
no need to pass around the rq_flag_bits bits too. btrfs users should
should access the bio insead.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:53 +0000 (14:31 -0500)]
btrfs: update __btrfs_map_block for REQ_OP transition
We no longer pass in a bitmap of rq_flag_bits bits to __btrfs_map_block.
It will always be a REQ_OP, or the btrfs specific REQ_GET_READ_MIRRORS,
so this drops the bit tests.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:51 +0000 (14:31 -0500)]
btrfs: have submit_one_bio users use bio op accessors
This patch has btrfs's submit_one_bio users set the bio op using
bio_set_op_attrs and get the op using bio_op.
The next patches will continue to convert btrfs,
so submit_bio_hook and merge_bio_hook
related code will be modified to take only the bio. I did
not do it in this patch to try and keep it smaller.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:50 +0000 (14:31 -0500)]
direct-io: use bio set/get op accessors
This patch has the dio code use a REQ_OP for the op and rq_flag_bits
for bi_rw flags. To set/get the op it uses the bio_set_op_attrs/bio_op
accssors.
It also begins to convert btrfs's dio_submit_t because of the dio
submit_io callout use. The next patches will completely convert
this code and the reset of the btrfs code paths.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:48 +0000 (14:31 -0500)]
block, fs, mm, drivers: use bio set/get op accessors
This patch converts the simple bi_rw use cases in the block,
drivers, mm and fs code to set/get the bio operation using
bio_set_op_attrs/bio_op
These should be simple one or two liner cases, so I just did them
in one patch. The next patches handle the more complicated
cases in a module per patch.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:47 +0000 (14:31 -0500)]
bcache: use op_is_write instead of checking for REQ_WRITE
We currently set REQ_WRITE/WRITE for all non READ IOs
like discard, flush, writesame, etc. In the next patches where we
no longer set up the op as a bitmap, we will not be able to
detect a operation direction like writesame by testing if REQ_WRITE is
set.
This has bcache use the op_is_write helper which will do the right
thing.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:46 +0000 (14:31 -0500)]
dm: use op_is_write instead of checking for REQ_WRITE
We currently set REQ_WRITE/WRITE for all non READ IOs
like discard, flush, writesame, etc. In the next patches where we
no longer set up the op as a bitmap, we will not be able to
detect a operation direction like writesame by testing if REQ_WRITE is
set.
This has dm use the op_is_write helper which will do the right
thing.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:45 +0000 (14:31 -0500)]
block, drivers, cgroup: use op_is_write helper instead of checking for REQ_WRITE
We currently set REQ_WRITE/WRITE for all non READ IOs
like discard, flush, writesame, etc. In the next patches where we
no longer set up the op as a bitmap, we will not be able to
detect a operation direction like writesame by testing if REQ_WRITE is
set.
This patch converts the drivers and cgroup to use the
op_is_write helper. This should just cover the simple
cases. I did dm, md and bcache in their own patches
because they were more involved.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:44 +0000 (14:31 -0500)]
fs: have ll_rw_block users pass in op and flags separately
This has ll_rw_block users pass in the operation and flags separately,
so ll_rw_block can setup the bio op and bi_rw flags on the bio that
is submitted.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:43 +0000 (14:31 -0500)]
fs: have submit_bh users pass in op and flags separately
This has submit_bh users pass in the operation and flags separately,
so submit_bh_wbc can setup the bio op and bi_rw flags on the bio that
is submitted.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:42 +0000 (14:31 -0500)]
block: add REQ_OP definitions and helpers
The following patches separate the operation (WRITE, READ, DISCARD,
etc) from the rq_flag_bits flags. This patch adds definitions for
request/bio operations (REQ_OPs) and adds request/bio accessors to
get/set the op.
In this patch the REQ_OPs match the REQ rq_flag_bits ones
for compat reasons while all the code is converted to use the
op accessors in the set. In the last patches the op will become a
number and the accessors and helpers in this patch will be dropped
or updated.
Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Mike Christie [Sun, 5 Jun 2016 19:31:41 +0000 (14:31 -0500)]
block/fs/drivers: remove rw argument from submit_bio
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Fixed up fs/ext4/crypto.c
Linus Torvalds [Sun, 5 Jun 2016 18:15:33 +0000 (11:15 -0700)]
Merge branch 'parisc-4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
- Fix printk time stamps on SMP systems which got wrong due to a patch
which was added during the merge window
- Fix two bugs in the stack backtrace code: Races in module unloading
and possible invalid accesses to memory due to wrong instruction
decoding (Mikulas Patocka)
- Fix userspace crash when syscalls access invalid unaligned userspace
addresses. Those syscalls will now return EFAULT as expected.
(tagged for stable kernel series)
* 'parisc-4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Move die_if_kernel() prototype into traps.h header
parisc: Fix pagefault crash in unaligned __get_user() call
parisc: Fix printk time during boot
parisc: Fix backtrace on PA-RISC
Linus Torvalds [Sun, 5 Jun 2016 18:02:00 +0000 (11:02 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull key handling update from James Morris:
"This alters a new keyctl function added in the current merge window to
allow for a future extension planned for the next merge window"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
KEYS: Add placeholder for KDF usage with DH
devpts: Make each mount of devpts an independent filesystem.
The /dev/ptmx device node is changed to lookup the directory entry "pts"
in the same directory as the /dev/ptmx device node was opened in. If
there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx
uses that filesystem. Otherwise the open of /dev/ptmx fails.
The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that
userspace can now safely depend on each mount of devpts creating a new
instance of the filesystem.
Each mount of devpts is now a separate and equal filesystem.
Reserved ttys are now available to all instances of devpts where the
mounter is in the initial mount namespace.
A new vfs helper path_pts is introduced that finds a directory entry
named "pts" in the directory of the passed in path, and changes the
passed in path to point to it. The helper path_pts uses a function
path_parent_directory that was factored out of follow_dotdot.
In the implementation of devpts:
- devpts_mnt is killed as it is no longer meaningful if all mounts of
devpts are equal.
- pts_sb_from_inode is replaced by just inode->i_sb as all cached
inodes in the tty layer are now from the devpts filesystem.
- devpts_add_ref is rolled into the new function devpts_ptmx. And the
unnecessary inode hold is removed.
- devpts_del_ref is renamed devpts_release and reduced to just a
deacrivate_super.
- The newinstance mount option continues to be accepted but is now
ignored.
In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as
they are never used.
Documentation/filesystems/devices.txt is updated to describe the current
situation.
This has been verified to work properly on openwrt-15.05, centos5,
centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3,
ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1,
slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01. With the
caveat that on centos6 and on slackware-14.1 that there wind up being
two instances of the devpts filesystem mounted on /dev/pts, the lower
copy does not end up getting used.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg KH <greg@kroah.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Jann Horn <jann@thejh.net> Cc: Jiri Slaby <jslaby@suse.com> Cc: Florian Weimer <fw@deneb.enyo.de> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This means the userspace program clock_adjtime called the clock_adjtime()
syscall and then crashed inside the compat_get_timex() function.
Syscalls should never crash programs, but instead return EFAULT.
The IIR register contains the executed instruction, which disassebles
into "ldw 0(sr3,r5),r9".
This load-word instruction is part of __get_user() which tried to read the word
at %r5/IOR (0xfa6f7fff). This means the unaligned handler jumped in. The
unaligned handler is able to emulate all ldw instructions, but it fails if it
fails to read the source e.g. because of page fault.
int main(void) {
/* allocate 8k */
char *ptr = mmap(NULL, 2*4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
/* free second half (upper 4k) and make it invalid. */
munmap(ptr+4096, 4096);
/* syscall where first int is unaligned and clobbers into invalid memory region */
/* syscall should return EFAULT */
return syscall(__NR_clock_adjtime, 0, ptr+4095);
}
To fix this issue we simply need to check if the faulting instruction address
is in the exception fixup table when the unaligned handler failed. If it
is, call the fixup routine instead of crashing.
While looking at the unaligned handler I found another issue as well: The
target register should not be modified if the handler was unsuccessful.
Mikulas Patocka [Tue, 28 Jun 2011 22:48:19 +0000 (00:48 +0200)]
parisc: Fix backtrace on PA-RISC
This patch fixes backtrace on PA-RISC
There were several problems:
1) The code that decodes instructions handles instructions that subtract
from the stack pointer incorrectly. If the instruction subtracts the
number X from the stack pointer the code increases the frame size by
(0x100000000-X). This results in invalid accesses to memory and
recursive page faults.
2) Because gcc reorders blocks, handling instructions that subtract from
the frame pointer is incorrect. For example, this function
int f(int a)
{
if (__builtin_expect(a, 1))
return a;
g();
return a;
}
is compiled in such a way, that the code that decreases the stack
pointer for the first "return a" is placed before the code for "g" call.
If we recognize this decrement, we mistakenly believe that the frame
size for the "g" call is zero.
To fix problems 1) and 2), the patch doesn't recognize instructions that
decrease the stack pointer at all. To further safeguard the unwind code
against nonsense values, we don't allow frame size larger than
Total_frame_size.
3) The backtrace is not locked. If stack dump races with module unload,
invalid table can be accessed.
This patch adds a spinlock when processing module tables.
Note, that for correct backtrace, you need recent binutils.
Binutils 2.18 from Debian 5 produce garbage unwind tables.
Binutils 2.21 work better (it sometimes forgets function frames, but at
least it doesn't generate garbage).
Linus Torvalds [Sat, 4 Jun 2016 19:30:36 +0000 (12:30 -0700)]
Merge tag 'drm-fixes-for-v4.7-rc2' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"A bunch of ARM drivers got into the fixes vibe this time around, so
this contains a bunch of fixes for imx, atmel hlcdc, arm hdlcd (only
so many combos of hlcd), mediatek and omap drm.
Other than that there is one mgag200 fix and a few core drm regression
fixes"
* tag 'drm-fixes-for-v4.7-rc2' of git://people.freedesktop.org/~airlied/linux: (34 commits)
drm/omap: fix unused variable warning.
drm: hdlcd: Add information about the underlying framebuffers in debugfs
drm: hdlcd: Cleanup the atomic plane operations
drm/hdlcd: Fix up crtc_state->event handling
drm: hdlcd: Revamp runtime power management
drm/mediatek: mtk_dsi: Remove spurious drm_connector_unregister
drm/mediatek: mtk_dpi: remove invalid error message
drm: atmel-hlcdc: fix a NULL check
drm: atmel-hlcdc: fix atmel_hlcdc_crtc_reset() implementation
drm/mgag200: Black screen fix for G200e rev 4
drm: Wrap direct calls to driver->gem_free_object from CMA
drm: fix fb refcount issue with atomic modesetting
drm: make drm_atomic_set_mode_prop_for_crtc() more reliable
drm/sti: remove extra mode fixup
drm: add missing drm_mode_set_crtcinfo call
drm/omap: include gpio/consumer.h where needed
drm/omap: include linux/seq_file.h where needed
Revert "drm/omap: no need to select OMAP2_DSS"
drm/omap: Remove regulator API abuse
OMAPDSS: HDMI5: Change DDC timings
...
Linus Torvalds [Sat, 4 Jun 2016 19:25:36 +0000 (12:25 -0700)]
Merge tag 'vfio-v4.7-rc2' of git://github.com/awilliam/linux-vfio
Pull VFIO fixes from Alex Williamson:
"Fix irqfd shutdown ordering, build warning, and VPD short read"
* tag 'vfio-v4.7-rc2' of git://github.com/awilliam/linux-vfio:
vfio/pci: Allow VPD short read
vfio/type1: Fix build warning
vfio/pci: Fix ordering of eventfd vs virqfd shutdown
Linus Torvalds [Sat, 4 Jun 2016 18:56:28 +0000 (11:56 -0700)]
Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"The important part of this pull is Filipe's set of fixes for btrfs
device replacement. Filipe fixed a few issues seen on the list and a
number he found on his own"
* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: deal with duplciates during extent_map insertion in btrfs_get_extent
Btrfs: fix race between device replace and read repair
Btrfs: fix race between device replace and discard
Btrfs: fix race between device replace and chunk allocation
Btrfs: fix race setting block group back to RW mode during device replace
Btrfs: fix unprotected assignment of the left cursor for device replace
Btrfs: fix race setting block group readonly during device replace
Btrfs: fix race between device replace and block group removal
Btrfs: fix race between readahead and device replace/removal
Linus Torvalds [Sat, 4 Jun 2016 18:37:53 +0000 (11:37 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fixes from Sage Weil:
"We have a few follow-up fixes for the libceph refactor from Ilya, and
then some cephfs + fscache fixes from Zheng.
The first two FS-Cache patches are acked by David Howells and deemed
trivial enough to go through our tree. The rest fix some issues with
the ceph fscache handling (disable cache for inodes opened for write,
and simplify the revalidation logic accordingly, dropping the
now-unnecessary work queue)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: use i_version to check validity of fscache
ceph: improve fscache revalidation
ceph: disable fscache when inode is opened for write
ceph: avoid unnecessary fscache invalidation/revlidation
ceph: call __fscache_uncache_page() if readpages fails
FS-Cache: make check_consistency callback return int
FS-Cache: wake write waiter after invalidating writes
libceph: use %s instead of %pE in dout()s
libceph: put request only if it's done in handle_reply()
libceph: change ceph_osdmap_flag() to take osdc
Linus Torvalds [Sat, 4 Jun 2016 18:26:49 +0000 (11:26 -0700)]
Merge tag 'acpi-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI fixes from Rafael Wysocki:
"Two fixes for problems introduced recently (ACPICA and the ACPI
backlight driver) and one fix for an older issue that prevents at
least one system from booting.
Specifics:
- Fix an incorrect check introduced by recent ACPICA changes which
causes problems with booting KVM guests to happen, among other
things (Lv Zheng).
- Fix a backlight issue introduced by recent changes to the ACPI
video driver (Aaron Lu).
- Fix the ACPI processor initialization which attempts to register an
IO region without checking if that really is necessary and
sometimes prevents drivers loaded subsequently from registering
their resources which leads to boot issues (Rafael Wysocki)"
* tag 'acpi-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / processor: Avoid reserving IO regions too early
ACPICA / Hardware: Fix old register check in acpi_hw_get_access_bit_width()
ACPI / Thermal / video: fix max_level incorrect value
Linus Torvalds [Sat, 4 Jun 2016 18:07:57 +0000 (11:07 -0700)]
Merge tag 'pm-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"Two fixes for problems introduced recently in the cpufreq core and the
intel_pstate driver.
Specifics:
- Fix a silly mistake related to the clamp_val() usage in a function
added by a recent commit (Rafael Wysocki).
- Reduce the log level of an annoying message added to intel_pstate
during the recent merge window (Srinivas Pandruvada)"
* tag 'pm-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: Fix clamp_val() usage in cpufreq_driver_fast_switch()
cpufreq: intel_pstate: Downgrade print level for _PPC
Linus Torvalds [Sat, 4 Jun 2016 17:51:29 +0000 (10:51 -0700)]
Merge branch 'akpm' (patches from Andrew)
Merge various fixes from Andrew Morton:
"10 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies
mm, page_alloc: reset zonelist iterator after resetting fair zone allocation policy
mm, oom_reaper: do not use siglock in try_oom_reaper()
mm, page_alloc: prevent infinite loop in buffered_rmqueue()
checkpatch: reduce git commit description style false positives
mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup
memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem()
mm: check the return value of lookup_page_ext for all call sites
kdump: fix dmesg gdbmacro to work with record based printk
mm: fix overflow in vm_map_ram()
Linus Torvalds [Fri, 3 Jun 2016 23:12:35 +0000 (16:12 -0700)]
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
- a few simple fixes for fallout from the recent gic-v3 changes
- a workaround for a Cavium thunderX erratum
- a bugfix for the pic32 irqchip to make external interrupts work proper
- a missing return value in the generic IPI management code
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/irq-pic32-evic: Fix bug with external interrupts.
irqchip/gicv3-its: numa: Enable workaround for Cavium thunderx erratum 23144
irqchip/gic-v3: Fix quiescence check in gic_enable_redist
irqchip/gic-v3: Fix copy+paste mistakes in defines
irqchip/gic-v3: Fix ICC_SGI1R_EL1.INTID decoding mask
genirq: Fix missing return value in irq_destroy_ipi()
Mel Gorman [Fri, 3 Jun 2016 21:56:01 +0000 (14:56 -0700)]
mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies
The optimistic fast path may use cpuset_current_mems_allowed instead of
of a NULL nodemask supplied by the caller for cpuset allocations. The
preferred zone is calculated on this basis for statistic purposes and as
a starting point in the zonelist iterator.
However, if the context can ignore memory policies due to being atomic
or being able to ignore watermarks then the starting point in the
zonelist iterator is no longer correct. This patch resets the zonelist
iterator in the allocator slowpath if the context can ignore memory
policies. This will alter the zone used for statistics but only after
it is known that it makes sense for that context. Resetting it before
entering the slowpath would potentially allow an ALLOC_CPUSET allocation
to be accounted for against the wrong zone. Note that while nodemask is
not explicitly set to the original nodemask, it would only have been
overwritten if cpuset_enabled() and it was reset before the slowpath was
entered.
Link: http://lkml.kernel.org/r/20160602103936.GU2527@techsingularity.net Fixes: c33d6c06f60f710 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Fri, 3 Jun 2016 21:55:58 +0000 (14:55 -0700)]
mm, page_alloc: reset zonelist iterator after resetting fair zone allocation policy
Geert Uytterhoeven reported the following problem that bisected to
commit c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone
in a zonelist twice") on m68k/ARAnyM
The relationship is not obvious but it's due to a failure to rescan the
full zonelist after the fair zone allocation policy exhausts the batch
count. While this is a functional problem, it's also a performance
issue. A page allocator microbenchmark showed the following
4.7.0-rc1 4.7.0-rc1
vanilla reset-v1r2
Min alloc-odr0-1 327.00 ( 0.00%) 326.00 ( 0.31%)
Min alloc-odr0-2 235.00 ( 0.00%) 235.00 ( 0.00%)
Min alloc-odr0-4 198.00 ( 0.00%) 198.00 ( 0.00%)
Min alloc-odr0-8 170.00 ( 0.00%) 170.00 ( 0.00%)
Min alloc-odr0-16 156.00 ( 0.00%) 156.00 ( 0.00%)
Min alloc-odr0-32 150.00 ( 0.00%) 150.00 ( 0.00%)
Min alloc-odr0-64 146.00 ( 0.00%) 146.00 ( 0.00%)
Min alloc-odr0-128 145.00 ( 0.00%) 145.00 ( 0.00%)
Min alloc-odr0-256 155.00 ( 0.00%) 155.00 ( 0.00%)
Min alloc-odr0-512 168.00 ( 0.00%) 165.00 ( 1.79%)
Min alloc-odr0-1024 175.00 ( 0.00%) 174.00 ( 0.57%)
Min alloc-odr0-2048 180.00 ( 0.00%) 180.00 ( 0.00%)
Min alloc-odr0-4096 187.00 ( 0.00%) 186.00 ( 0.53%)
Min alloc-odr0-8192 190.00 ( 0.00%) 190.00 ( 0.00%)
Min alloc-odr0-16384 191.00 ( 0.00%) 191.00 ( 0.00%)
Min alloc-odr1-1 736.00 ( 0.00%) 445.00 ( 39.54%)
Min alloc-odr1-2 343.00 ( 0.00%) 335.00 ( 2.33%)
Min alloc-odr1-4 277.00 ( 0.00%) 270.00 ( 2.53%)
Min alloc-odr1-8 238.00 ( 0.00%) 233.00 ( 2.10%)
Min alloc-odr1-16 224.00 ( 0.00%) 218.00 ( 2.68%)
Min alloc-odr1-32 210.00 ( 0.00%) 208.00 ( 0.95%)
Min alloc-odr1-64 207.00 ( 0.00%) 203.00 ( 1.93%)
Min alloc-odr1-128 276.00 ( 0.00%) 202.00 ( 26.81%)
Min alloc-odr1-256 206.00 ( 0.00%) 202.00 ( 1.94%)
Min alloc-odr1-512 207.00 ( 0.00%) 202.00 ( 2.42%)
Min alloc-odr1-1024 208.00 ( 0.00%) 205.00 ( 1.44%)
Min alloc-odr1-2048 213.00 ( 0.00%) 212.00 ( 0.47%)
Min alloc-odr1-4096 218.00 ( 0.00%) 216.00 ( 0.92%)
Min alloc-odr1-8192 341.00 ( 0.00%) 219.00 ( 35.78%)
Note that order-0 allocations are unaffected but higher orders get a
small boost from this patch and a large reduction in system CPU usage
overall as can be seen here:
4.7.0-rc1 4.7.0-rc1
vanilla reset-v1r2
User 85.32 86.31
System 2221.39 2053.36
Elapsed 2368.89 2202.47
Fixes: c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Link: http://lkml.kernel.org/r/20160531100848.GR2527@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Fri, 3 Jun 2016 21:55:55 +0000 (14:55 -0700)]
mm, oom_reaper: do not use siglock in try_oom_reaper()
Oleg has noted that siglock usage in try_oom_reaper is both pointless
and dangerous. signal_group_exit can be checked lockless. The problem
is that sighand becomes NULL in __exit_signal so we can crash.
Fixes: 3ef22dfff239 ("oom, oom_reaper: try to reap tasks which skip regular OOM killer path") Link: http://lkml.kernel.org/r/1464679423-30218-1-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Fri, 3 Jun 2016 21:55:52 +0000 (14:55 -0700)]
mm, page_alloc: prevent infinite loop in buffered_rmqueue()
In DEBUG_VM kernel, we can hit infinite loop for order == 0 in
buffered_rmqueue() when check_new_pcp() returns 1, because the bad page
is never removed from the pcp list. Fix this by removing the page
before retrying. Also we don't need to check if page is non-NULL,
because we simply grab it from the list which was just tested for being
non-empty.
Fixes: 479f854a207c ("mm, page_alloc: defer debugging checks of pages allocated from the PCP") Link: http://lkml.kernel.org/r/20160530090154.GM2527@techsingularity.net Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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