28 Jun, 2015
1 commit
-
Whenever blk_fill_sghdr_rq fails, its errno code is ignored and changed to
EFAULT. This can cause very confusing errors:$ sg_persist -k /dev/sda
persistent reservation in: pass through os error: Bad addressThe fix is trivial, just propagate the return value from
blk_fill_sghdr_rq.Signed-off-by: Paolo Bonzini
Acked-by: Jeff Moyer
Signed-off-by: Jens Axboe
27 Jun, 2015
1 commit
-
Pull device mapper fixes from Mike Snitzer:
"Apologies for not pressing this request-based DM partial completion
issue further, it was an oversight on my part. We'll have to get it
fixed up properly and revisit for a future release.- Revert block and DM core changes the removed request-based DM's
ability to handle partial request completions -- otherwise with the
current SCSI LLDs these changes could lead to silent data
corruption.- Fix two DM version bumps that were missing from the initial 4.2 DM
pull request (enabled userspace lvm2 to know certain changes have
been made)"* tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm cache policy smq: fix "default" version to be 1.4.0
dm: bump the ioctl version to 4.32.0
Revert "block, dm: don't copy bios for request clones"
Revert "dm: do not allocate any mempools for blk-mq request-based DM"
26 Jun, 2015
3 commits
-
This reverts commit 5f1b670d0bef508a5554d92525f5f6d00d640b38.
Justification for revert as reported in this dm-devel post:
https://www.redhat.com/archives/dm-devel/2015-June/msg00160.htmlthis change should not be pushed to mainline yet.
Firstly, Christoph has a newer version of the patch that fixes silent
data corruption problem:
https://www.redhat.com/archives/dm-devel/2015-May/msg00229.htmlAnd the new version still depends on LLDDs to always complete requests
to the end when error happens, while block API doesn't enforce such a
requirement. If the assumption is ever broken, the inconsistency between
request and bio (e.g. rq->__sector and rq->bio) will cause silent data
corruption:
https://www.redhat.com/archives/dm-devel/2015-June/msg00022.htmlReported-by: Junichi Nomura
Signed-off-by: Mike Snitzer -
Pull cgroup writeback support from Jens Axboe:
"This is the big pull request for adding cgroup writeback support.This code has been in development for a long time, and it has been
simmering in for-next for a good chunk of this cycle too. This is one
of those problems that has been talked about for at least half a
decade, finally there's a solution and code to go with it.Also see last weeks writeup on LWN:
http://lwn.net/Articles/648292/"
* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
writeback, blkio: add documentation for cgroup writeback support
vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
writeback: do foreign inode detection iff cgroup writeback is enabled
v9fs: fix error handling in v9fs_session_init()
bdi: fix wrong error return value in cgwb_create()
buffer: remove unusued 'ret' variable
writeback: disassociate inodes from dying bdi_writebacks
writeback: implement foreign cgroup inode bdi_writeback switching
writeback: add lockdep annotation to inode_to_wb()
writeback: use unlocked_inode_to_wb transaction in inode_congested()
writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
writeback: implement [locked_]inode_to_wb_and_lock_list()
writeback: implement foreign cgroup inode detection
writeback: make writeback_control track the inode being written back
writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
writeback: implement memcg writeback domain based throttling
writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
writeback: implement memcg wb_domain
writeback: update wb_over_bg_thresh() to use wb_domain aware operations
... -
Pull core block IO update from Jens Axboe:
"Nothing really major in here, mostly a collection of smaller
optimizations and cleanups, mixed with various fixes. In more detail,
this contains:- Addition of policy specific data to blkcg for block cgroups. From
Arianna Avanzini.- Various cleanups around command types from Christoph.
- Cleanup of the suspend block I/O path from Christoph.
- Plugging updates from Shaohua and Jeff Moyer, for blk-mq.
- Eliminating atomic inc/dec of both remaining IO count and reference
count in a bio. From me.- Fixes for SG gap and chunk size support for data-less (discards)
IO, so we can merge these better. From me.- Small restructuring of blk-mq shared tag support, freeing drivers
from iterating hardware queues. From Keith Busch.- A few cfq-iosched tweaks, from Tahsin Erdogan and me. Makes the
IOPS mode the default for non-rotational storage"* 'for-4.2/core' of git://git.kernel.dk/linux-block: (35 commits)
cfq-iosched: fix other locations where blkcg_to_cfqgd() can return NULL
cfq-iosched: fix sysfs oops when attempting to read unconfigured weights
cfq-iosched: move group scheduling functions under ifdef
cfq-iosched: fix the setting of IOPS mode on SSDs
blktrace: Add blktrace.c to BLOCK LAYER in MAINTAINERS file
block, cgroup: implement policy-specific per-blkcg data
block: Make CFQ default to IOPS mode on SSDs
block: add blk_set_queue_dying() to blkdev.h
blk-mq: Shared tag enhancements
block: don't honor chunk sizes for data-less IO
block: only honor SG gap prevention for merges that contain data
block: fix returnvar.cocci warnings
block, dm: don't copy bios for request clones
block: remove management of bi_remaining when restoring original bi_end_io
block: replace trylock with mutex_lock in blkdev_reread_part()
block: export blkdev_reread_part() and __blkdev_reread_part()
suspend: simplify block I/O handling
block: collapse bio bit space
block: remove unused BIO_RW_BLOCK and BIO_EOF flags
block: remove BIO_EOPNOTSUPP
...
23 Jun, 2015
1 commit
-
Pull scheduler updates from Ingo Molnar:
"The main changes are:- lockless wakeup support for futexes and IPC message queues
(Davidlohr Bueso, Peter Zijlstra)- Replace spinlocks with atomics in thread_group_cputimer(), to
improve scalability (Jason Low)- NUMA balancing improvements (Rik van Riel)
- SCHED_DEADLINE improvements (Wanpeng Li)
- clean up and reorganize preemption helpers (Frederic Weisbecker)
- decouple page fault disabling machinery from the preemption
counter, to improve debuggability and robustness (David
Hildenbrand)- SCHED_DEADLINE documentation updates (Luca Abeni)
- topology CPU masks cleanups (Bartosz Golaszewski)
- /proc/sched_debug improvements (Srikar Dronamraju)"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
sched/deadline: Remove needless parameter in dl_runtime_exceeded()
sched: Remove superfluous resetting of the p->dl_throttled flag
sched/deadline: Drop duplicate init_sched_dl_class() declaration
sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target
sched/deadline: Make init_sched_dl_class() __init
sched/deadline: Optimize pull_dl_task()
sched/preempt: Add static_key() to preempt_notifiers
sched/preempt: Fix preempt notifiers documentation about hlist_del() within unsafe iteration
sched/stop_machine: Fix deadlock between multiple stop_two_cpus()
sched/debug: Add sum_sleep_runtime to /proc//sched
sched/debug: Replace vruntime with wait_sum in /proc/sched_debug
sched/debug: Properly format runnable tasks in /proc/sched_debug
sched/numa: Only consider less busy nodes as numa balancing destinations
Revert 095bebf61a46 ("sched/numa: Do not move past the balance point if unbalanced")
sched/fair: Prevent throttling in early pick_next_task_fair()
preempt: Reorganize the notrace definitions a bit
preempt: Use preempt_schedule_context() as the official tracing preemption point
sched: Make preempt_schedule_context() function-tracing safe
x86: Remove cpu_sibling_mask() and cpu_core_mask()
x86: Replace cpu_**_mask() with topology_**_cpumask()
...
21 Jun, 2015
1 commit
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Commit 9470e4a693db only covered the initial bug report, there are
other spots in CFQ where we need to check that we actually have
a valid cfq_group_data structure.Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data")
Signed-off-by: Jens Axboe
20 Jun, 2015
2 commits
-
If none of the devices in the system are using CFQ, then attempting to
read:/sys/fs/cgroup/blkio/blkio.leaf_weight
will results in a NULL dereference. Check for a valid cfq_group_data
struct before attempting to dereference it.Reported-by: Andrey Wagin
Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data")
Signed-off-by: Jens Axboe -
If CFQ_GROUP_IOSCHED is not set, the compiler produces the
following warning:CC block/cfq-iosched.o
linux/block/cfq-iosched.c:469:2:
warning: 'cpd_to_cfqgd' defined but not used [-Wunused-function]
*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
^In reality, two other lookup functions aren't used either if
CFQ_GROUP_IOSCHED isn't set. Move all three under one of the
CFQ_GROUP_IOSCHED sections in the code.Reported-by: Vladimir Zapolskiy
Signed-off-by: Jens Axboe
11 Jun, 2015
1 commit
-
=================================
[ INFO: inconsistent lock state ]
4.1.0-rc7+ #217 Tainted: G O
---------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/6/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
(ext_devt_lock){+.?...}, at: [] blk_free_devt+0x3c/0x70
{SOFTIRQ-ON-W} state was registered at:
[] __lock_acquire+0x461/0x1e70
[] lock_acquire+0xb7/0x290
[] _raw_spin_lock+0x38/0x50
[] blk_alloc_devt+0x6d/0xd0 ] __lock_acquire+0x3fe/0x1e70
[] ? __lock_acquire+0xe5d/0x1e70
[] lock_acquire+0xb7/0x290
[] ? blk_free_devt+0x3c/0x70
[] _raw_spin_lock+0x38/0x50
[] ? blk_free_devt+0x3c/0x70
[] blk_free_devt+0x3c/0x70 ] part_release+0x1c/0x50
[] device_release+0x36/0xb0
[] kobject_cleanup+0x7b/0x1a0
[] kobject_put+0x30/0x70
[] put_device+0x17/0x20
[] delete_partition_rcu_cb+0x16c/0x180
[] ? read_dev_sector+0xa0/0xa0
[] rcu_process_callbacks+0x2ff/0xa90
[] ? rcu_process_callbacks+0x2bf/0xa90
[] __do_softirq+0xde/0x600Neil sees this in his tests and it also triggers on pmem driver unbind
for the libnvdimm tests. This fix is on top of an initial fix by Keith
for incorrect usage of mutex_lock() in this path: 2da78092dda1 "block:
Fix dev_t minor allocation lifetime". Both this and 2da78092dda1 are
candidates for -stable.Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime")
Cc:
Cc: Keith Busch
Reported-by: NeilBrown
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe
10 Jun, 2015
2 commits
-
A previous commit wanted to make CFQ default to IOPS mode on
non-rotational storage, however it did so when the queue was
initialized and the non-rotational flag is only set later on
in the probe.Add an elevator hook that gets called off the add_disk() path,
at that point we know that feature probing has finished, and
we can reliably check for the various flags that drivers can
set.Fixes: 41c0126b ("block: Make CFQ default to IOPS mode on SSDs")
Tested-by: Romain Francoise
Signed-off-by: Jens Axboe -
Now blk_cleanup_queue() can be called before calling
del_gendisk()[1], inside which hctx->ctxs is touched
from blk_mq_unregister_hctx(), but the variable has
been freed by blk_cleanup_queue() at that time.So this patch moves freeing of hctx->ctxs into queue's
release handler for fixing the oops reported by Stefan.[1], 6cd18e711dd8075 (block: destroy bdi before blockdev is
unregistered)Reported-by: Stefan Seyfried
Cc: NeilBrown
Cc: Christoph Hellwig
Cc: stable@vger.kernel.org (v4.0)
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe
07 Jun, 2015
1 commit
-
The block IO (blkio) controller enables the block layer to provide service
guarantees in a hierarchical fashion. Specifically, service guarantees
are provided by registered request-accounting policies. As of now, a
proportional-share and a throttling policy are available. They are
implemented, respectively, by the CFQ I/O scheduler and the blk-throttle
subsystem. Unfortunately, as for adding new policies, the current
implementation of the block IO controller is only halfway ready to allow
new policies to be plugged in. This commit provides a solution to make
the block IO controller fully ready to handle new policies.
In what follows, we first describe briefly the current state, and then
list the changes made by this commit.The throttling policy does not need any per-cgroup information to perform
its task. In contrast, the proportional share policy uses, for each cgroup,
both the weight assigned by the user to the cgroup, and a set of dynamically-
computed weights, one for each device.The first, user-defined weight is stored in the blkcg data structure: the
block IO controller allocates a private blkcg data structure for each
cgroup in the blkio cgroups hierarchy (regardless of which policy is active).
In other words, the block IO controller internally mirrors the blkio cgroups
with private blkcg data structures.On the other hand, for each cgroup and device, the corresponding dynamically-
computed weight is maintained in the following, different way. For each device,
the block IO controller keeps a private blkcg_gq structure for each cgroup in
blkio. In other words, block IO also keeps one private mirror copy of the blkio
cgroups hierarchy for each device, made of blkcg_gq structures.
Each blkcg_gq structure keeps per-policy information in a generic array of
dynamically-allocated 'dedicated' data structures, one for each registered
policy (so currently the array contains two elements). To be inserted into the
generic array, each dedicated data structure embeds a generic blkg_policy_data
structure. Consider now the array contained in the blkcg_gq structure
corresponding to a given pair of cgroup and device: one of the elements
of the array contains the dedicated data structure for the proportional-share
policy, and this dedicated data structure contains the dynamically-computed
weight for that pair of cgroup and device.The generic strategy adopted for storing per-policy data in blkcg_gq structures
is already capable of handling new policies, whereas the one adopted with blkcg
structures is not, because per-policy data are hard-coded in the blkcg
structures themselves (currently only data related to the proportional-
share policy).This commit addresses the above issues through the following changes:
. It generalizes blkcg structures so that per-policy data are stored in the same
way as in blkcg_gq structures.
Specifically, it lets also the blkcg structure store per-policy data in a
generic array of dynamically-allocated dedicated data structures. We will
refer to these data structures as blkcg dedicated data structures, to
distinguish them from the dedicated data structures inserted in the generic
arrays kept by blkcg_gq structures.
To allow blkcg dedicated data structures to be inserted in the generic array
inside a blkcg structure, this commit also introduces a new blkcg_policy_data
structure, which is the equivalent of blkg_policy_data for blkcg dedicated
data structures.
. It adds to the blkcg_policy structure, i.e., to the descriptor of a policy, a
cpd_size field and a cpd_init field, to be initialized by the policy with,
respectively, the size of the blkcg dedicated data structures, and the
address of a constructor function for blkcg dedicated data structures.
. It moves the CFQ-specific fields embedded in the blkcg data structure (i.e.,
the fields related to the proportional-share policy), into a new blkcg
dedicated data structure called cfq_group_data.Signed-off-by: Paolo Valente
Signed-off-by: Arianna Avanzini
Acked-by: Tejun Heo
Cc: Jens Axboe
Signed-off-by: Jens Axboe
06 Jun, 2015
1 commit
-
CFQ idling causes reduced IOPS throughput on non-rotational disks.
Since disk head seeking is not applicable to SSDs, it doesn't really
help performance by anticipating future near-by IO requests.By turning off idling (and switching to IOPS mode), we allow other
processes to dispatch IO requests down to the driver and so increase IO
throughput.Following FIO benchmark results were taken on a cloud SSD offering with
idling on and off:Idling iops avg-lat(ms) stddev bw
------------------------------------------------------
On 7054 90.107 38.697 28217KB/s
Off 29255 21.836 11.730 117022KB/sfio --name=temp --size=100G --time_based --ioengine=libaio \
--randrepeat=0 --direct=1 --invalidate=1 --verify=0 \
--verify_fatal=0 --rw=randread --blocksize=4k --group_reporting=1 \
--filename=/dev/sdb --runtime=10 --iodepth=64 --numjobs=10And the following is from a local SSD run:
Idling iops avg-lat(ms) stddev bw
------------------------------------------------------
On 19320 33.043 14.068 77281KB/s
Off 21626 29.465 12.662 86507KB/sfio --name=temp --size=5G --time_based --ioengine=libaio \
--randrepeat=0 --direct=1 --invalidate=1 --verify=0 \
--verify_fatal=0 --rw=randread --blocksize=4k --group_reporting=1 \
--filename=/fio_data --runtime=10 --iodepth=64 --numjobs=10Reviewed-by: Nauman Rafique
Signed-off-by: Tahsin Erdogan
Signed-off-by: Jens Axboe
02 Jun, 2015
14 commits
-
Now that bdi layer can handle per-blkcg bdi_writeback_congested state,
blk_{set|clear}_congested() can propagate non-root blkcg congestion
state to them.This can be easily achieved by disabling the root_rl tests in
blk_{set|clear}_congested(). Note that we still need those tests when
!CONFIG_CGROUP_WRITEBACK as otherwise we'll end up flipping root blkcg
wb's congestion state for events happening on other blkcgs.v2: Updated for bdi_writeback_congested.
Signed-off-by: Tejun Heo
Cc: Jens Axboe
Cc: Jan Kara
Cc: Vivek Goyal
Signed-off-by: Jens Axboe -
blk_{set|clear}_queue_congested() take @q and set or clear,
respectively, the congestion state of its bdi's root wb. Because bdi
used to be able to handle congestion state only on the root wb, the
callers of those functions tested whether the congestion is on the
root blkcg and skipped if not.This is cumbersome and makes implementation of per cgroup
bdi_writeback congestion state propagation difficult. This patch
renames blk_{set|clear}_queue_congested() to
blk_{set|clear}_congested(), and makes them take request_list instead
of request_queue and test whether the specified request_list is the
root one before updating bdi_writeback congestion state. This makes
the tests in the callers unnecessary and simplifies them.As there are no external users of these functions, the definitions are
moved from include/linux/blkdev.h to block/blk-core.c.This patch doesn't introduce any noticeable behavior difference.
Signed-off-by: Tejun Heo
Cc: Jens Axboe
Cc: Jan Kara
Cc: Vivek Goyal
Signed-off-by: Jens Axboe -
A blkg (blkcg_gq) can be congested and decongested independently from
other blkgs on the same request_queue. Accordingly, for cgroup
writeback support, the congestion status at bdi (backing_dev_info)
should be split and updated separately from matching blkg's.This patch prepares by adding blkg->wb_congested and associating a
blkg with its matching per-blkcg bdi_writeback_congested on creation.v2: Updated to associate bdi_writeback_congested instead of
bdi_writeback.Signed-off-by: Tejun Heo
Cc: Jens Axboe
Cc: Jan Kara
Cc: Vivek Goyal
Signed-off-by: Jens Axboe -
For the planned cgroup writeback support, on each bdi
(backing_dev_info), each memcg will be served by a separate wb
(bdi_writeback). This patch updates bdi so that a bdi can host
multiple wbs (bdi_writebacks).On the default hierarchy, blkcg implicitly enables memcg. This allows
using memcg's page ownership for attributing writeback IOs, and every
memcg - blkcg combination can be served by its own wb by assigning a
dedicated wb to each memcg. This means that there may be multiple
wb's of a bdi mapped to the same blkcg. As congested state is per
blkcg - bdi combination, those wb's should share the same congested
state. This is achieved by tracking congested state via
bdi_writeback_congested structs which are keyed by blkcg.bdi->wb remains unchanged and will keep serving the root cgroup.
cgwb's (cgroup wb's) for non-root cgroups are created on-demand or
looked up while dirtying an inode according to the memcg of the page
being dirtied or current task. Each cgwb is indexed on bdi->cgwb_tree
by its memcg id. Once an inode is associated with its wb, it can be
retrieved using inode_to_wb().Currently, none of the filesystems has FS_CGROUP_WRITEBACK and all
pages will keep being associated with bdi->wb.v3: inode_attach_wb() in account_page_dirtied() moved inside
mapping_cap_account_dirty() block where it's known to be !NULL.
Also, an unnecessary NULL check before kfree() removed. Both
detected by the kbuild bot.v2: Updated so that wb association is per inode and wb is per memcg
rather than blkcg.Signed-off-by: Tejun Heo
Cc: kbuild test robot
Cc: Dan Carpenter
Cc: Jens Axboe
Cc: Jan Kara
Signed-off-by: Jens Axboe -
cgroup writeback requires support from both bdi and filesystem sides.
Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate
support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by
default. Also, define CONFIG_CGROUP_WRITEBACK which is enabled if
both MEMCG and BLK_CGROUP are enabled.inode_cgwb_enabled() which determines whether a given inode's both bdi
and fs support cgroup writeback is added.Signed-off-by: Tejun Heo
Cc: Jens Axboe
Cc: Jan Kara
Signed-off-by: Jens Axboe -
With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it. c files
which need access to more backing-dev details now include
backing-dev.h directly. This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.v2: fs/fat build failure fixed.
Signed-off-by: Tejun Heo
Reviewed-by: Jan Kara
Cc: Jens Axboe
Signed-off-by: Jens Axboe -
Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear. For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi. To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.This patch moves bdi->state into wb.
* enum bdi_state is renamed to wb_state and the prefix of all enums is
changed from BDI_ to WB_.* Explicit zeroing of bdi->state is removed without adding zeoring of
wb->state as the whole data structure is zeroed on init anyway.* As there's still only one bdi_writeback per backing_dev_info, all
uses of bdi->state are mechanically replaced with bdi->wb.state
introducing no behavior changes.Signed-off-by: Tejun Heo
Reviewed-by: Jan Kara
Cc: Jens Axboe
Cc: Wu Fengguang
Cc: drbd-dev@lists.linbit.com
Cc: Neil Brown
Cc: Alasdair Kergon
Cc: Mike Snitzer
Signed-off-by: Jens Axboe -
Currently, a bio can only be associated with the io_context and blkcg
of %current using bio_associate_current(). This is too restrictive
for cgroup writeback support. Implement bio_associate_blkcg() which
associates a bio with the specified blkcg.bio_associate_blkcg() leaves the io_context unassociated.
bio_associate_current() is updated so that it considers a bio as
already associated if it has a blkcg_css, instead of an io_context,
associated with it.Signed-off-by: Tejun Heo
Cc: Jens Axboe
Cc: Vivek Goyal
Signed-off-by: Jens Axboe -
bio_associate_current() currently open codes task_css() and
css_tryget_online() to find and pin $current's blkcg css. Abstract it
into task_get_css() which is implemented from cgroup side. As a task
is always associated with an online css for every subsystem except
while the css_set update is propagating, task_get_css() retries till
css_tryget_online() succeeds.This is a cleanup and shouldn't lead to noticeable behavior changes.
Signed-off-by: Tejun Heo
Cc: Li Zefan
Cc: Jens Axboe
Cc: Vivek Goyal
Signed-off-by: Jens Axboe -
Add global constant blkcg_root_css which points to &blkcg_root.css.
This will be used by cgroup writeback support. If blkcg is disabled,
it's defined as ERR_PTR(-EINVAL).v2: The declarations moved to include/linux/blk-cgroup.h as suggested
by Vivek.Signed-off-by: Tejun Heo
Cc: Vivek Goyal
Cc: Jens Axboe
Signed-off-by: Jens Axboe -
Currently, blkcg does a minor optimization where the root blkcg is
created when the first blkcg policy is activated on a queue and
destroyed on the deactivation of the last. On systems where blkcg is
configured but not used, this saves one blkcg_gq struct per queue. On
systems where blkcg is actually used, there's no difference. The only
case where this can lead to any meaninful, albeit still minute, save
in memory consumption is when all blkcg policies are deactivated after
being widely used in the system, which is a hihgly unlikely scenario.The conditional existence of root blkcg_gq has already created several
bugs in blkcg and became an issue once again for the new per-cgroup
wb_congested mechanism for cgroup writeback support leading to a NULL
dereference when no blkcg policy is active. This is really not worth
bothering with. This patch makes blkcg always allocate and link the
root blkcg_gq and release it only on queue destruction.Signed-off-by: Tejun Heo
Reported-by: Fengguang Wu
Signed-off-by: Jens Axboe -
cgroup aware writeback support will require exposing some of blkcg
details. In preprataion, move block/blk-cgroup.h to
include/linux/blk-cgroup.h. This patch is pure file move.Signed-off-by: Tejun Heo
Cc: Vivek Goyal
Signed-off-by: Jens Axboe -
Conflicts:
arch/sparc/include/asm/topology_64.hSigned-off-by: Ingo Molnar
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Storage controllers may expose multiple block devices that share hardware
resources managed by blk-mq. This patch enhances the shared tags so a
low-level driver can access the shared resources not tied to the unshared
h/w contexts. This way the LLD can dynamically add and delete disks and
request queues without having to track all the request_queue hctx's to
iterate outstanding tags.Signed-off-by: Keith Busch
Signed-off-by: Jens Axboe
30 May, 2015
2 commits
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We can safely merge anything that wont generate an SG list entry,
so if the bio is data-less (discard), don't look at potential
SG gaps.Signed-off-by: Jens Axboe
29 May, 2015
1 commit
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bdi_unregister() now contains very little functionality.
It contains a "WARN_ON" if bdi->dev is NULL. This warning is of no
real consequence as bdi->dev isn't needed by anything else in the function,
and it triggers if
blk_cleanup_queue() -> bdi_destroy()
is called before bdi_unregister, which happens since
Commit: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.")So this isn't wanted.
It also calls bdi_set_min_ratio(). This needs to be called after
writes through the bdi have all been flushed, and before the bdi is destroyed.
Calling it early is better than calling it late as it frees up a global
resource.Calling it immediately after bdi_wb_shutdown() in bdi_destroy()
perfectly fits these requirements.So bdi_unregister() can be discarded with the important content moved to
bdi_destroy(), as can the
writeback_bdi_unregister
event which is already not used.Reported-by: Mike Snitzer
Cc: stable@vger.kernel.org (v4.0)
Fixes: c4db59d31e39 ("fs: don't reassign dirty inodes to default_backing_dev_info")
Fixes: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.")
Acked-by: Peter Zijlstra (Intel)
Acked-by: Dan Williams
Tested-by: Nicholas Moulin
Signed-off-by: NeilBrown
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe
27 May, 2015
1 commit
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Rename topology_thread_cpumask() to topology_sibling_cpumask()
for more consistency with scheduler code.Signed-off-by: Bartosz Golaszewski
Reviewed-by: Thomas Gleixner
Acked-by: Russell King
Acked-by: Catalin Marinas
Cc: Benoit Cousson
Cc: Fenghua Yu
Cc: Guenter Roeck
Cc: Jean Delvare
Cc: Jonathan Corbet
Cc: Linus Torvalds
Cc: Oleg Drokin
Cc: Peter Zijlstra
Cc: Rafael J. Wysocki
Cc: Russell King
Cc: Viresh Kumar
Link: http://lkml.kernel.org/r/1432645896-12588-2-git-send-email-bgolaszewski@baylibre.com
Signed-off-by: Ingo Molnar
22 May, 2015
2 commits
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Currently dm-multipath has to clone the bios for every request sent
to the lower devices, which wastes cpu cycles and ties down memory.This patch instead adds a new REQ_CLONE flag that instructs req_bio_endio
to not complete bios attached to a request, which we set on clone
requests similar to bios in a flush sequence. With this change I/O
errors on a path failure only get propagated to dm-multipath, which
can then either resubmit the I/O or complete the bios on the original
request.I've done some basic testing of this on a Linux target with ALUA support,
and it survives path failures during I/O nicely.Signed-off-by: Christoph Hellwig
Signed-off-by: Mike Snitzer
Signed-off-by: Jens Axboe -
Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for
non-chains") regressed all existing callers that followed this pattern:
1) saving a bio's original bi_end_io
2) wiring up an intermediate bi_end_io
3) restoring the original bi_end_io from intermediate bi_end_io
4) calling bio_endio() to execute the restored original bi_end_ioThe regression was due to BIO_CHAIN only ever getting set if
bio_inc_remaining() is called. For the above pattern it isn't set until
step 3 above (step 2 would've needed to establish BIO_CHAIN). As such
the first bio_endio(), in step 2 above, never decremented __bi_remaining
before calling the intermediate bi_end_io -- leaving __bi_remaining with
the value 1 instead of 0. When bio_inc_remaining() occurred during step
3 it brought it to a value of 2. When the second bio_endio() was
called, in step 4 above, it should've called the original bi_end_io but
it didn't because there was an extra reference that wasn't dropped (due
to atomic operations being optimized away since BIO_CHAIN wasn't set
upfront).Fix this issue by removing the __bi_remaining management complexity for
all callers that use the above pattern -- bio_chain() is the only
interface that _needs_ to be concerned with __bi_remaining. For the
above pattern callers just expect the bi_end_io they set to get called!
Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls
that aren't associated with the bio_chain() interface.Also, the bio_inc_remaining() interface has been moved local to bio.c.
Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains")
Reviewed-by: Christoph Hellwig
Reviewed-by: Jan Kara
Signed-off-by: Mike Snitzer
Signed-off-by: Jens Axboe
20 May, 2015
2 commits
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The only possible problem of using mutex_lock() instead of trylock
is about deadlock.If there aren't any locks held before calling blkdev_reread_part(),
deadlock can't be caused by this conversion.If there are locks held before calling blkdev_reread_part(),
and if these locks arn't required in open, close handler and I/O
path, deadlock shouldn't be caused too.Both user space's ioctl(BLKRRPART) and md_setup_drive() from
init/do_mounts_md.c belongs to the 1st case, so the conversion is safe
for the two cases.For loop, the previous patches in this pathset has fixed the ABBA lock
dependency, so the conversion is OK.For nbd, tx_lock is held when calling the function:
- both open and release won't hold the lock
- when blkdev_reread_part() is run, I/O thread has been stopped
already, so tx_lock won't be acquired in I/O path at that time.
- so the conversion won't cause deadlock for nbdFor dasd, both dasd_open(), dasd_release() and request function don't
acquire any mutex/semphone, so the conversion should be safe.Reviewed-by: Christoph Hellwig
Tested-by: Jarod Wilson
Acked-by: Jarod Wilson
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe -
This patch exports blkdev_reread_part() for block drivers, also
introduce __blkdev_reread_part().For some drivers, such as loop, reread of partitions can be run
from the release path, and bd_mutex may already be held prior to
calling ioctl_by_bdev(bdev, BLKRRPART, 0), so introduce
__blkdev_reread_part for use in such cases.CC: Christoph Hellwig
CC: Jens Axboe
CC: Tejun Heo
CC: Alexander Viro
CC: Markus Pargmann
CC: Stefan Weinhuber
CC: Stefan Haberland
CC: Sebastian Ott
CC: Fabian Frederick
CC: Ming Lei
CC: David Herrmann
CC: Andrew Morton
CC: Peter Zijlstra
CC: nbd-general@lists.sourceforge.net
CC: linux-s390@vger.kernel.org
Reviewed-by: Christoph Hellwig
Signed-off-by: Jarod Wilson
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe
19 May, 2015
3 commits
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Signed-off-by: Christoph Hellwig
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe -
Since the big barrier rewrite/removal in 2007 we never fail FLUSH or
FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag
to help propagating those to the buffer_head layer.Signed-off-by: Christoph Hellwig
Reviewed-by: Jeff Moyer
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe -
lockdep gets unhappy about the not disabling irqs when using the queue_lock
around it. Instead of trying to fix that up just switch to an atomic_t
and get rid of the lock.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
13 May, 2015
1 commit
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With commit ff36ab345 ("dm: remove request-based logic from
make_request_fn wrapper") DM no longer calls blk_queue_bio() directly,
so remove its export. Doing so required a forward declaration in
blk-core.c.Signed-off-by: Mike Snitzer
Signed-off-by: Jens Axboe