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4235 commits

Author SHA1 Message Date
Linus Torvalds 5166701b36 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The first vfs pile, with deep apologies for being very late in this
  window.

  Assorted cleanups and fixes, plus a large preparatory part of iov_iter
  work.  There's a lot more of that, but it'll probably go into the next
  merge window - it *does* shape up nicely, removes a lot of
  boilerplate, gets rid of locking inconsistencie between aio_write and
  splice_write and I hope to get Kent's direct-io rewrite merged into
  the same queue, but some of the stuff after this point is having
  (mostly trivial) conflicts with the things already merged into
  mainline and with some I want more testing.

  This one passes LTP and xfstests without regressions, in addition to
  usual beating.  BTW, readahead02 in ltp syscalls testsuite has started
  giving failures since "mm/readahead.c: fix readahead failure for
  memoryless NUMA nodes and limit readahead pages" - might be a false
  positive, might be a real regression..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  missing bits of "splice: fix racy pipe->buffers uses"
  cifs: fix the race in cifs_writev()
  ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
  kill generic_file_buffered_write()
  ocfs2_file_aio_write(): switch to generic_perform_write()
  ceph_aio_write(): switch to generic_perform_write()
  xfs_file_buffered_aio_write(): switch to generic_perform_write()
  export generic_perform_write(), start getting rid of generic_file_buffer_write()
  generic_file_direct_write(): get rid of ppos argument
  btrfs_file_aio_write(): get rid of ppos
  kill the 5th argument of generic_file_buffered_write()
  kill the 4th argument of __generic_file_aio_write()
  lustre: don't open-code kernel_recvmsg()
  ocfs2: don't open-code kernel_recvmsg()
  drbd: don't open-code kernel_recvmsg()
  constify blk_rq_map_user_iov() and friends
  lustre: switch to kernel_sendmsg()
  ocfs2: don't open-code kernel_sendmsg()
  take iov_iter stuff to mm/iov_iter.c
  process_vm_access: tidy up a bit
  ...
2014-04-12 14:49:50 -07:00
Linus Torvalds 3e8072d48b Merge git://git.infradead.org/users/willy/linux-nvme
Pull NVMe driver updates from Matthew Wilcox:
 "Various updates to the NVMe driver.  The most user-visible change is
  that drive hotplugging now works and CPU hotplug while an NVMe drive
  is installed should also work better"

* git://git.infradead.org/users/willy/linux-nvme:
  NVMe: Retry failed commands with non-fatal errors
  NVMe: Add getgeo to block ops
  NVMe: Start-stop nvme_thread during device add-remove.
  NVMe: Make I/O timeout a module parameter
  NVMe: CPU hot plug notification
  NVMe: per-cpu io queues
  NVMe: Replace DEFINE_PCI_DEVICE_TABLE
  NVMe: Fix divide-by-zero in nvme_trans_io_get_num_cmds
  NVMe: IOCTL path RCU protect queue access
  NVMe: RCU protected access to io queues
  NVMe: Initialize device reference count earlier
  NVMe: Add CONFIG_PM_SLEEP to suspend/resume functions
2014-04-11 16:45:59 -07:00
Keith Busch edd10d3328 NVMe: Retry failed commands with non-fatal errors
For commands returned with failed status, queue these for resubmission
and continue retrying them until success or for a limited amount of
time. The final timeout was arbitrarily chosen so requests can't be
retried indefinitely.

Since these are requeued on the nvmeq that submitted the command, the
callbacks have to take an nvmeq instead of an nvme_dev as a parameter
so that we can use the locked queue to append the iod to retry later.

The nvme_iod conviently can be used to track how long we've been trying
to successfully complete an iod request. The nvme_iod also provides the
nvme prp dma mappings, so I had to move a few things around so we can
keep those mappings.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[fixed checkpatch issue with long line]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:11:59 -04:00
Keith Busch 4cc09e2dc4 NVMe: Add getgeo to block ops
Some programs require HDIO_GETGEO work, which requires we implement
getgeo.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:06:11 -04:00
Dan McLeran b9afca3efb NVMe: Start-stop nvme_thread during device add-remove.
Done to ensure nvme_thread is not running when there
are no devices to poll.

Signed-off-by: Dan McLeran <daniel.mcleran@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:04:46 -04:00
Keith Busch b355084a89 NVMe: Make I/O timeout a module parameter
Increase the default timeout to 30 seconds to match SCSI.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[use byte instead of ushort]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:04:38 -04:00
Keith Busch 33b1e95c90 NVMe: CPU hot plug notification
Registers with hot cpu notification to rebalance, and potentially allocate
additional, io queues.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:03:42 -04:00
Keith Busch 42f614201e NVMe: per-cpu io queues
The device's IO queues are associated with CPUs, so we can use a per-cpu
variable to map the a qid to a cpu. This provides a convienient way
to optimally assign queues to multiple cpus when the device supports
fewer queues than the host has cpus. The previous implementation may
have assigned these poorly in these situations. This patch addresses
this by sharing queues among cpus that are "close" together and should
have a lower lock contention penalty.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-04-10 17:03:15 -04:00
Linus Torvalds dd76a786af Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "A small collection of fixes that should go in before -rc1.  The pull
  request contains:

   - A two patch fix for a regression with block enabled tagging caused
     by a commit in the initial pull request.  One patch is from Martin
     and ensures that SCSI doesn't truncate 64-bit block flags, the
     other one is from me and prevents us from double using struct
     request queuelist for both completion and busy tags.  This caused
     anything from a boot crash for some, to crashes under load.

   - A blk-mq fix for a potential soft stall when hot unplugging CPUs
     with busy IO.

   - percpu_counter fix is listed in here, that caused a suspend issue
     with virtio-blk due to percpu counters having an inconsistent state
     during CPU removal.  Andrew sent this in separately a few days ago,
     but it's here.  JFYI.

   - A few fixes for block integrity from Martin.

   - A ratelimit fix for loop from Mike Galbraith, to avoid spewing too
     much in error cases"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix regression with block enabled tagging
  scsi: Make sure cmd_flags are 64-bit
  block: Ensure we only enable integrity metadata for reads and writes
  block: Fix integrity verification
  block: Fix for_each_bvec()
  drivers/block/loop.c: ratelimit error messages
  blk-mq: fix potential stall during CPU unplug with IO pending
  percpu_counter: fix bad counter state during suspend
2014-04-10 09:26:55 -07:00
Mike Galbraith 44bd70c347 drivers/block/loop.c: ratelimit error messages
Metric tons of high speed spew is not helpful when things go pear shaped.
systemd lost its mind, forgot how to stop services it insists on being
sole manager of, massive printk() flood ensued, box eventually died.

[16206.684000] loop: Write error at byte offset 11412291584, length 4096.
[16206.684000] systemd-journald[1758]: /dev/kmsg buffer overrun, some messages lost.
[16206.684000] loop: Write error at byte offset 13155434496, length 4096.
[16206.684000] loop: Write error at byte offset 13155438592, length 4096.
[16206.684000] loop: Write error at byte offset 13155442688, length 4096.
[16206.684000] loop: Write error at byte offset 13960736768, length 4096.
[16206.684000] loop: Write error at byte offset 14229172224, length 4096.
[16206.684000] systemd-journald[1758]: /dev/kmsg buffer overrun, some messages lost.
[16206.684000] loop: Write error at byte offset 14766043136, length 4096.
[16206.684000] loop: Write error at byte offset 15034478592, length 4096.
[16206.684000] systemd-journald[1758]: /dev/kmsg buffer overrun, some messages lost.

Signed-off-by: Mike Galbraith <bitbucket@online.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-08 14:44:35 -06:00
Linus Torvalds 26c12d9334 Merge branch 'akpm' (incoming from Andrew)
Merge second patch-bomb from Andrew Morton:
 - the rest of MM
 - zram updates
 - zswap updates
 - exit
 - procfs
 - exec
 - wait
 - crash dump
 - lib/idr
 - rapidio
 - adfs, affs, bfs, ufs
 - cris
 - Kconfig things
 - initramfs
 - small amount of IPC material
 - percpu enhancements
 - early ioremap support
 - various other misc things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (156 commits)
  MAINTAINERS: update Intel C600 SAS driver maintainers
  fs/ufs: remove unused ufs_super_block_third pointer
  fs/ufs: remove unused ufs_super_block_second pointer
  fs/ufs: remove unused ufs_super_block_first pointer
  fs/ufs/super.c: add __init to init_inodecache()
  doc/kernel-parameters.txt: add early_ioremap_debug
  arm64: add early_ioremap support
  arm64: initialize pgprot info earlier in boot
  x86: use generic early_ioremap
  mm: create generic early_ioremap() support
  x86/mm: sparse warning fix for early_memremap
  lglock: map to spinlock when !CONFIG_SMP
  percpu: add preemption checks to __this_cpu ops
  vmstat: use raw_cpu_ops to avoid false positives on preemption checks
  slub: use raw_cpu_inc for incrementing statistics
  net: replace __this_cpu_inc in route.c with raw_cpu_inc
  modules: use raw_cpu_write for initialization of per cpu refcount.
  mm: use raw_cpu ops for determining current NUMA node
  percpu: add raw_cpu_ops
  slub: fix leak of 'name' in sysfs_slab_add
  ...
2014-04-07 16:38:06 -07:00
Joonsoo Kim f4659d8e62 zram: support REQ_DISCARD
zram is ram based block device and can be used by backend of filesystem.
When filesystem deletes a file, it normally doesn't do anything on data
block of that file.  It just marks on metadata of that file.  This
behavior has no problem on disk based block device, but has problems on
ram based block device, since we can't free memory used for data block.
To overcome this disadvantage, there is REQ_DISCARD functionality.  If
block device support REQ_DISCARD and filesystem is mounted with discard
option, filesystem sends REQ_DISCARD to block device whenever some data
blocks are discarded.  All we have to do is to handle this request.

This patch implements to flag up QUEUE_FLAG_DISCARD and handle this
REQ_DISCARD request.  With it, we can free memory used by zram if it isn't
used.

[akpm@linux-foundation.org: tweak comments]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:02 -07:00
Sergey Senozhatsky 56b4e8cb85 zram: use scnprintf() in attrs show() methods
sysfs.txt documentation lists the following requirements:

 - The buffer will always be PAGE_SIZE bytes in length. On i386, this
   is 4096.

 - show() methods should return the number of bytes printed into the
   buffer. This is the return value of scnprintf().

 - show() should always use scnprintf().

Use scnprintf() in show() functions.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:02 -07:00
Minchan Kim 60a726e333 zram: propagate error to user
When we initialized zcomp with single, we couldn't change
max_comp_streams without zram reset but current interface doesn't show
any error to user and even it changes max_comp_streams's value without
any effect so it would make user very confusing.

This patch prevents max_comp_streams's change when zcomp was initialized
as single zcomp and emit the error to user(ex, echo).

[akpm@linux-foundation.org: don't return with the lock held, per Sergey]
[fengguang.wu@intel.com: fix coccinelle warnings]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:02 -07:00
Sergey Senozhatsky fcfa8d95ca zram: return error-valued pointer from zcomp_create()
Instead of returning just NULL, return ERR_PTR from zcomp_create() if
compressing backend creation has failed.  ERR_PTR(-EINVAL) for unsupported
compression algorithm request, ERR_PTR(-ENOMEM) for allocation (zcomp or
compression stream) error.

Perform IS_ERR() check of returned from zcomp_create() value in
disksize_store() and set return code to PTR_ERR().

Change suggested by Jerome Marchand.

[akpm@linux-foundation.org: clean up error recovery flow]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:02 -07:00
Sergey Senozhatsky d61f98c70e zram: move comp allocation out of init_lock
While fixing lockdep spew of ->init_lock reported by Sasha Levin [1],
Minchan Kim noted [2] that it's better to move compression backend
allocation (using GPF_KERNEL) out of the ->init_lock lock, same way as
with zram_meta_alloc(), in order to prevent the same lockdep spew.

[1] https://lkml.org/lkml/2014/2/27/337
[2] https://lkml.org/lkml/2014/3/3/32

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:02 -07:00
Sergey Senozhatsky 6e76668e41 zram: add lz4 algorithm backend
Introduce LZ4 compression backend and make it available for selection.
LZ4 support is optional and requires user to set ZRAM_LZ4_COMPRESS config
option.  The default compression backend is LZO.

TEST

(x86_64, core i5, 2 cores + 2 hyperthreading, zram disk size 1G,
ext4 file system, 3 compression streams)

iozone -t 3 -R -r 16K -s 60M -I +Z

       Test           LZO           LZ4
----------------------------------------------
  Initial write   1642744.62    1317005.09
        Rewrite   2498980.88    1800645.16
           Read   3957026.38    5877043.75
        Re-read   3950997.38    5861847.00
   Reverse Read   2937114.56    5047384.00
    Stride read   2948163.19    4929587.38
    Random read   3292692.69    4880793.62
 Mixed workload   1545602.62    3502940.38
   Random write   2448039.75    1758786.25
         Pwrite   1670051.03    1338329.69
          Pread   2530682.00    5097177.62
         Fwrite   3232085.62    3275942.56
          Fread   6306880.25    6645271.12

So on my system LZ4 is slower in write-only tests, while it performs
better in read-only and mixed (reads + writes) tests.

Official LZ4 benchmarks available here http://code.google.com/p/lz4/
(linux kernel uses revision r90).

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:01 -07:00
Sergey Senozhatsky e46b8a030d zram: make compression algorithm selection possible
Add and document `comp_algorithm' device attribute.  This attribute allows
to show supported compression and currently selected compression
algorithms:

	cat /sys/block/zram0/comp_algorithm
	[lzo] lz4

and change selected compression algorithm:
	echo lzo > /sys/block/zram0/comp_algorithm

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:01 -07:00
Sergey Senozhatsky fe8eb122c8 zram: add set_max_streams knob
This patch allows to change max_comp_streams on initialised zcomp.

Introduce zcomp set_max_streams() knob, zcomp_strm_multi_set_max_streams()
and zcomp_strm_single_set_max_streams() callbacks to change streams limit
for zcomp_strm_multi and zcomp_strm_single, accordingly.  set_max_streams
for single steam zcomp does nothing.

If user has lowered the limit, then zcomp_strm_multi_set_max_streams()
attempts to immediately free extra streams (as much as it can, depending
on idle streams availability).

Note, this patch does not allow to change stream 'policy' from single to
multi stream (or vice versa) on already initialised compression backend.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:01 -07:00
Sergey Senozhatsky beca3ec71f zram: add multi stream functionality
Existing zram (zcomp) implementation has only one compression stream
(buffer and algorithm private part), so in order to prevent data
corruption only one write (compress operation) can use this compression
stream, forcing all concurrent write operations to wait for stream lock
to be released.  This patch changes zcomp to keep a compression streams
list of user-defined size (via sysfs device attr).  Each write operation
still exclusively holds compression stream, the difference is that we
can have N write operations (depending on size of streams list)
executing in parallel.  See TEST section later in commit message for
performance data.

Introduce struct zcomp_strm_multi and a set of functions to manage
zcomp_strm stream access.  zcomp_strm_multi has a list of idle
zcomp_strm structs, spinlock to protect idle list and wait queue, making
it possible to perform parallel compressions.

The following set of functions added:
- zcomp_strm_multi_find()/zcomp_strm_multi_release()
  find and release a compression stream, implement required locking
- zcomp_strm_multi_create()/zcomp_strm_multi_destroy()
  create and destroy zcomp_strm_multi

zcomp ->strm_find() and ->strm_release() callbacks are set during
initialisation to zcomp_strm_multi_find()/zcomp_strm_multi_release()
correspondingly.

Each time zcomp issues a zcomp_strm_multi_find() call, the following set
of operations performed:

- spin lock strm_lock
- if idle list is not empty, remove zcomp_strm from idle list, spin
  unlock and return zcomp stream pointer to caller
- if idle list is empty, current adds itself to wait queue. it will be
  awaken by zcomp_strm_multi_release() caller.

zcomp_strm_multi_release():
- spin lock strm_lock
- add zcomp stream to idle list
- spin unlock, wake up sleeper

Minchan Kim reported that spinlock-based locking scheme has demonstrated
a severe perfomance regression for single compression stream case,
comparing to mutex-based (see https://lkml.org/lkml/2014/2/18/16)

base                      spinlock                    mutex

==Initial write           ==Initial write             ==Initial  write
records:  5               records:  5                 records:   5
avg:      1642424.35      avg:      699610.40         avg:       1655583.71
std:      39890.95(2.43%) std:      232014.19(33.16%) std:       52293.96
max:      1690170.94      max:      1163473.45        max:       1697164.75
min:      1568669.52      min:      573429.88         min:       1553410.23
==Rewrite                 ==Rewrite                   ==Rewrite
records:  5               records:  5                 records:   5
avg:      1611775.39      avg:      501406.64         avg:       1684419.11
std:      17144.58(1.06%) std:      15354.41(3.06%)   std:       18367.42
max:      1641800.95      max:      531356.78         max:       1706445.84
min:      1593515.27      min:      488817.78         min:       1655335.73

When only one compression stream available, mutex with spin on owner
tends to perform much better than frequent wait_event()/wake_up().  This
is why single stream implemented as a special case with mutex locking.

Introduce and document zram device attribute max_comp_streams.  This
attr shows and stores current zcomp's max number of zcomp streams
(max_strm).  Extend zcomp's zcomp_create() with `max_strm' parameter.
`max_strm' limits the number of zcomp_strm structs in compression
backend's idle list (max_comp_streams).

max_comp_streams used during initialisation as follows:
-- passing to zcomp_create() max_strm equals to 1 will initialise zcomp
using single compression stream zcomp_strm_single (mutex-based locking).
-- passing to zcomp_create() max_strm greater than 1 will initialise zcomp
using multi compression stream zcomp_strm_multi (spinlock-based locking).

default max_comp_streams value is 1, meaning that zram with single stream
will be initialised.

Later patch will introduce configuration knob to change max_comp_streams
on already initialised and used zcomp.

TEST
iozone -t 3 -R -r 16K -s 60M -I +Z

       test           base       1 strm (mutex)     3 strm (spinlock)
-----------------------------------------------------------------------
 Initial write      589286.78       583518.39          718011.05
       Rewrite      604837.97       596776.38         1515125.72
  Random write      584120.11       595714.58         1388850.25
        Pwrite      535731.17       541117.38          739295.27
        Fwrite     1418083.88      1478612.72         1484927.06

Usage example:
set max_comp_streams to 4
        echo 4 > /sys/block/zram0/max_comp_streams

show current max_comp_streams (default value is 1).
        cat /sys/block/zram0/max_comp_streams

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:01 -07:00
Sergey Senozhatsky 9cc97529a1 zram: factor out single stream compression
This is preparation patch to add multi stream support to zcomp.

Introduce struct zcomp_strm_single and a set of functions to manage
zcomp_strm stream access.  zcomp_strm_single implements single compession
stream, same way as current zcomp implementation.  This moves zcomp_strm
stream control and locking from zcomp, so compressing backend zcomp is not
aware of required locking.

Single and multi streams require different locking schemes.  Minchan Kim
reported that spinlock-based locking scheme (which is used in multi stream
implementation) has demonstrated a severe perfomance regression for single
compression stream case, comparing to mutex-based.  see
https://lkml.org/lkml/2014/2/18/16

The following set of functions added:
- zcomp_strm_single_find()/zcomp_strm_single_release()
  find and release a compression stream, implement required locking
- zcomp_strm_single_create()/zcomp_strm_single_destroy()
  create and destroy zcomp_strm_single

New ->strm_find() and ->strm_release() callbacks added to zcomp, which are
set to zcomp_strm_single_find() and zcomp_strm_single_release() during
initialisation.  Instead of direct locking and zcomp_strm access from
zcomp_strm_find() and zcomp_strm_release(), zcomp now calls ->strm_find()
and ->strm_release() correspondingly.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:01 -07:00
Sergey Senozhatsky b7ca232ee7 zram: use zcomp compressing backends
Do not perform direct LZO compress/decompress calls, initialise
and use zcomp LZO backend (single compression stream) instead.

[akpm@linux-foundation.org: resolve conflicts with zram-delete-zram_init_device-fix.patch]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:01 -07:00
Sergey Senozhatsky e7e1ef439d zram: introduce compressing backend abstraction
ZRAM performs direct LZO compression algorithm calls, making it the one
and only option.  While LZO is generally performs well, LZ4 algorithm
tends to have a faster decompression (see http://code.google.com/p/lz4/
for full report)

	Name            Ratio  C.speed D.speed
	                        MB/s    MB/s
	LZ4 (r101)      2.084    422    1820
	LZO 2.06        2.106    414     600

Thus, users who have mostly read (decompress) usage scenarious or mixed
workflow (writes with relatively high read ops number) will benefit from
using LZ4 compression backend.

Introduce compressing backend abstraction zcomp in order to support
multiple compression algorithms with the following set of operations:

        .create
        .destroy
        .compress
        .decompress

Schematically zram write() usually contains the following steps:
0) preparation (decompression of partioal IO, etc.)
1) lock buffer_lock mutex (protects meta compress buffers)
2) compress (using meta compress buffers)
3) alloc and map zs_pool object
4) copy compressed data (from meta compress buffers) to object allocated by 3)
5) free previous pool page, assign a new one
6) unlock buffer_lock mutex

As we can see, compressing buffers must remain untouched from 1) to 4),
because, otherwise, concurrent write() can overwrite data.  At the same
time, zram_meta must be aware of a) specific compression algorithm memory
requirements and b) necessary locking to protect compression buffers.  To
remove requirement a) new struct zcomp_strm introduced, which contains a
compress/decompress `buffer' and compression algorithm `private' part.
While struct zcomp implements zcomp_strm stream handling and locking and
removes requirement b) from zram meta.  zcomp ->create() and ->destroy(),
respectively, allocate and deallocate algorithm specific zcomp_strm
`private' part.

Every zcomp has zcomp stream and mutex to protect its compression stream.
Stream usage semantics remains the same -- only one write can hold stream
lock and use its buffers.  zcomp_strm_find() turns caller into exclusive
user of a stream (holding stream mutex until zram release stream), and
zcomp_strm_release() makes zcomp stream available (unlock the stream
mutex).  Hence no concurrent write (compression) operations possible at
the moment.

iozone -t 3 -R -r 16K -s 60M -I +Z

       test            base           patched
--------------------------------------------------
  Initial write      597992.91       591660.58
        Rewrite      609674.34       616054.97
           Read     2404771.75      2452909.12
        Re-read     2459216.81      2470074.44
   Reverse Read     1652769.66      1589128.66
    Stride read     2202441.81      2202173.31
    Random read     2236311.47      2276565.31
 Mixed workload     1423760.41      1709760.06
   Random write      579584.08       615933.86
         Pwrite      597550.02       594933.70
          Pread     1703672.53      1718126.72
         Fwrite     1330497.06      1461054.00
          Fread     3922851.00      3957242.62

Usage examples:

	comp = zcomp_create(NAME) /* NAME e.g. "lzo" */

which initialises compressing backend if requested algorithm is supported.

Compress:
	zstrm = zcomp_strm_find(comp)
	zcomp_compress(comp, zstrm, src, &dst_len)
	[..] /* copy compressed data */
	zcomp_strm_release(comp, zstrm)

Decompress:
	zcomp_decompress(comp, src, src_len, dst);

Free compessing backend and its zcomp stream:
	zcomp_destroy(comp)

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:01 -07:00
Sergey Senozhatsky b67d1ec189 zram: delete zram_init_device()
allocate new `zram_meta' in disksize_store() only for uninitialised zram
device, saving a number of allocations and deallocations in case if
disksize_store() was called on currently used device.  at the same time
zram_meta stack variable is not necessary, because we can set ->meta
directly.  there is also no need in setting QUEUE_FLAG_NONROT queue on
every disksize_store(), set it once during device creation.

[minchan@kernel.org: handle zram->meta alloc fail case]
[minchan@kernel.org: prevent lockdep spew of init_lock]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:00 -07:00
Sergey Senozhatsky e64cd51d2f zram: move zram size warning to documentation
Move zram warning about disksize and size of memory correlation to zram
documentation.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:00 -07:00
Sergey Senozhatsky 59fc86a492 zram: drop not used table `count' member
struct table `count' member is not used.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:00 -07:00
Sergey Senozhatsky 6444724939 zram: report failed read and write stats
zram accounted but did not report numbers of failed read and write
queries.  make these stats available as failed_reads and failed_writes
attrs.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:00 -07:00
Sergey Senozhatsky a68eb3b65e zram: remove zram stats code duplication
Introduce ZRAM_ATTR_RO macro that generates device_attribute and default
ATTR show() function for existing atomic64_t zram stats.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:00 -07:00
Sergey Senozhatsky 90a7806ea9 zram: use atomic64_t for all zram stats
This is a preparation patch for stats code duplication removal.

1) use atomic64_t for `pages_zero' and `pages_stored' zram stats.

2) `compr_size' and `pages_zero' struct zram_stats members did not
   follow the existing device attr naming scheme: zram_stats.ATTR has
   ATTR_show() function.  rename them:

   -- compr_size -> compr_data_size
   -- pages_zero -> zero_pages

Minchan Kim's note:
 If we really have trouble with atomic stat operation, we could
 change it with percpu_counter so that it could solve atomic overhead and
 unnecessary memory space by introducing unsigned long instead of 64bit
 atomic_t.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:59 -07:00
Sergey Senozhatsky b7cccf8b40 zram: remove good and bad compress stats
Remove `good' and `bad' compressed sub-requests stats.  RW request may
cause a number of RW sub-requests.  zram used to account `good' compressed
sub-queries (with compressed size less than 50% of original size), `bad'
compressed sub-queries (with compressed size greater that 75% of original
size), leaving sub-requests with compression size between 50% and 75% of
original size not accounted and not reported.  zram already accounts each
sub-request's compression size so we can calculate real device compression
ratio.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:59 -07:00
Sergey Senozhatsky be257c6130 zram: do not pass rw argument to __zram_make_request()
Do not pass rw argument down the __zram_make_request() -> zram_bvec_rw()
chain, decode it in zram_bvec_rw() instead.  Besides, this is the place
where we distinguish READ and WRITE bio data directions, so account zram
RW stats here, instead of __zram_make_request().  This also allows to
account a real number of zram READ/WRITE operations, not just requests
(single RW request may cause a number of zram RW ops with separate
locking, compression/decompression, etc).

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:59 -07:00
Sergey Senozhatsky be2d1d56c8 zram: drop `init_done' struct zram member
Introduce init_done() helper function which allows us to drop `init_done'
struct zram member.  init_done() uses the fact that ->init_done == 1
equals to ->meta != NULL.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:59 -07:00
Linus Torvalds 240cd6a817 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph updates from Sage Weil:
 "The biggest chunk is a series of patches from Ilya that add support
  for new Ceph osd and crush map features, including some new tunables,
  primary affinity, and the new encoding that is needed for erasure
  coding support.  This brings things into parity with the server side
  and the looming firefly release.  There is also support for allocation
  hints in RBD that help limit fragmentation on the server side.

  There is also a series of patches from Zheng fixing NFS reexport,
  directory fragmentation support, flock vs fnctl behavior, and some
  issues with clustered MDS.

  Finally, there are some miscellaneous fixes from Yunchuan Wen for
  fscache, Fabian Frederick for ACLs, and from me for fsync(dirfd)
  behavior"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (79 commits)
  ceph: skip invalid dentry during dcache readdir
  libceph: dump pool {read,write}_tier to debugfs
  libceph: output primary affinity values on osdmap updates
  ceph: flush cap release queue when trimming session caps
  ceph: don't grabs open file reference for aborted request
  ceph: drop extra open file reference in ceph_atomic_open()
  ceph: preallocate buffer for readdir reply
  libceph: enable PRIMARY_AFFINITY feature bit
  libceph: redo ceph_calc_pg_primary() in terms of ceph_calc_pg_acting()
  libceph: add support for osd primary affinity
  libceph: add support for primary_temp mappings
  libceph: return primary from ceph_calc_pg_acting()
  libceph: switch ceph_calc_pg_acting() to new helpers
  libceph: introduce apply_temps() helper
  libceph: introduce pg_to_raw_osds() and raw_to_up_osds() helpers
  libceph: ceph_can_shift_osds(pool) and pool type defines
  libceph: ceph_osd_{exists,is_up,is_down}(osd) definitions
  libceph: enable OSDMAP_ENC feature bit
  libceph: primary_affinity decode bits
  libceph: primary_affinity infrastructure
  ...
2014-04-07 11:09:13 -07:00
Ilya Dryomov 0ccd592669 rbd: prefix rbd writes with CEPH_OSD_OP_SETALLOCHINT osd op
In an effort to reduce fragmentation, prefix every rbd write with
a CEPH_OSD_OP_SETALLOCHINT osd op with an expected_write_size value set
to the object size (1 << order).  Backwards compatibility is taken care
of on the libceph/osd side.

"The CEPH_OSD_OP_SETALLOCHINT hint is durable, in that it's enough to
do it once.  The reason every rbd write is prefixed is that rbd doesn't
explicitly create objects and relies on writes creating them
implicitly, so there is no place to stick a single hint op into.  To
get around that we decided to prefix every rbd write with a hint (just
like write and setattr ops, hint op will create an object implicitly if
it doesn't exist)."

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov deb236b300 rbd: num_ops parameter for rbd_osd_req_create()
In preparation for prefixing rbd writes with an allocation hint
introduce a num_ops parameter for rbd_osd_req_create().  The rationale
is that not every write request is a write op that needs to be prefixed
(e.g. watch op), so the num_ops logic needs to be in the callers.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov 7cc69d42e6 libceph: bump CEPH_OSD_MAX_OP to 3
Our longest osd request now contains 3 ops: copyup+hint+write.

Also, CEPH_OSD_MAX_OP value in a BUG_ON in rbd_osd_req_callback() was
hard-coded to 2.  Fix it, and switch to rbd_assert while at it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov 42dd037c08 rbd: fix error paths in rbd_img_request_fill()
Doing rbd_obj_request_put() in rbd_img_request_fill() error paths is
not only insufficient, but also triggers an rbd_assert() in
rbd_obj_request_destroy():

    Assertion failure in rbd_obj_request_destroy() at line 1867:

    rbd_assert(obj_request->img_request == NULL);

rbd_img_obj_request_add() adds obj_requests to the img_request, the
opposite is rbd_img_obj_request_del().  Use it.

Fixes: http://tracker.ceph.com/issues/7327

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:51 +08:00
Ilya Dryomov 62054da65c rbd: remove out_partial label in rbd_img_request_fill()
Commit 03507db631 ("rbd: fix buffer size for writes to images with
snapshots") moved the call to rbd_img_obj_request_add() up, making the
out_partial label bogus.  Remove it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:50 +08:00
Linus Torvalds 64056a9425 Nothing exciting: virtio-blk users might see a bit of a boost from the
doubling of the default queue length though.
 
 Cheers,
 Rusty.
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Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio updates from Rusty Russell:
 "Nothing exciting: virtio-blk users might see a bit of a boost from the
  doubling of the default queue length though"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio-blk: base queue-depth on virtqueue ringsize or module param
  Revert a02bbb1ccf: MAINTAINERS: add virtio-dev ML for virtio
  virtio: fail adding buffer on broken queues.
  virtio-rng: don't crash if virtqueue is broken.
  virtio_balloon: don't crash if virtqueue is broken.
  virtio_blk: don't crash, report error if virtqueue is broken.
  virtio_net: don't crash if virtqueue is broken.
  virtio_balloon: don't softlockup on huge balloon changes.
  virtio: Use pci_enable_msix_exact() instead of pci_enable_msix()
  MAINTAINERS: virtio-dev is subscribers only
  tools/virtio: add a missing )
  tools/virtio: fix missing kmemleak_ignore symbol
  tools/virtio: update internal copies of headers
2014-04-02 14:43:17 -07:00
Al Viro f730c848af drbd: don't open-code kernel_recvmsg()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:32 -04:00
Al Viro e25115786e switch nbd to sockfd_lookup/sockfd_put
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:10 -04:00
Linus Torvalds b33ce44299 Merge branch 'for-3.15/drivers' of git://git.kernel.dk/linux-block
Pull block driver update from Jens Axboe:
 "On top of the core pull request, here's the pull request for the
  driver related changes for 3.15.  It contains:

   - Improvements for msi-x registration for block drivers (mtip32xx,
     skd, cciss, nvme) from Alexander Gordeev.

   - A round of cleanups and improvements for drbd from Andreas
     Gruenbacher and Rashika Kheria.

   - A round of clanups and improvements for bcache from Kent.

   - Removal of sleep_on() and friends in DAC960, ataflop, swim3 from
     Arnd Bergmann.

   - Bug fix for a bug in the mtip32xx async completion code from Sam
     Bradshaw.

   - Bug fix for accidentally bouncing IO on 32-bit platforms with
     mtip32xx from Felipe Franciosi"

* 'for-3.15/drivers' of git://git.kernel.dk/linux-block: (103 commits)
  bcache: remove nested function usage
  bcache: Kill bucket->gc_gen
  bcache: Kill unused freelist
  bcache: Rework btree cache reserve handling
  bcache: Kill btree_io_wq
  bcache: btree locking rework
  bcache: Fix a race when freeing btree nodes
  bcache: Add a real GC_MARK_RECLAIMABLE
  bcache: Add bch_keylist_init_single()
  bcache: Improve priority_stats
  bcache: Better alloc tracepoints
  bcache: Kill dead cgroup code
  bcache: stop moving_gc marking buckets that can't be moved.
  bcache: Fix moving_pred()
  bcache: Fix moving_gc deadlocking with a foreground write
  bcache: Fix discard granularity
  bcache: Fix another bug recovering from unclean shutdown
  bcache: Fix a bug recovering from unclean shutdown
  bcache: Fix a journalling reclaim after recovery bug
  bcache: Fix a null ptr deref in journal replay
  ...
2014-04-01 19:43:53 -07:00
Linus Torvalds 7a48837732 Merge branch 'for-3.15/core' of git://git.kernel.dk/linux-block
Pull core block layer updates from Jens Axboe:
 "This is the pull request for the core block IO bits for the 3.15
  kernel.  It's a smaller round this time, it contains:

   - Various little blk-mq fixes and additions from Christoph and
     myself.

   - Cleanup of the IPI usage from the block layer, and associated
     helper code.  From Frederic Weisbecker and Jan Kara.

   - Duplicate code cleanup in bio-integrity from Gu Zheng.  This will
     give you a merge conflict, but that should be easy to resolve.

   - blk-mq notify spinlock fix for RT from Mike Galbraith.

   - A blktrace partial accounting bug fix from Roman Pen.

   - Missing REQ_SYNC detection fix for blk-mq from Shaohua Li"

* 'for-3.15/core' of git://git.kernel.dk/linux-block: (25 commits)
  blk-mq: add REQ_SYNC early
  rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock
  blk-mq: support partial I/O completions
  blk-mq: merge blk_mq_insert_request and blk_mq_run_request
  blk-mq: remove blk_mq_alloc_rq
  blk-mq: don't dump CPU -> hw queue map on driver load
  blk-mq: fix wrong usage of hctx->state vs hctx->flags
  blk-mq: allow blk_mq_init_commands() to return failure
  block: remove old blk_iopoll_enabled variable
  blktrace: fix accounting of partially completed requests
  smp: Rename __smp_call_function_single() to smp_call_function_single_async()
  smp: Remove wait argument from __smp_call_function_single()
  watchdog: Simplify a little the IPI call
  smp: Move __smp_call_function_single() below its safe version
  smp: Consolidate the various smp_call_function_single() declensions
  smp: Teach __smp_call_function_single() to check for offline cpus
  smp: Remove unused list_head from csd
  smp: Iterate functions through llist_for_each_entry_safe()
  block: Stop abusing rq->csd.list in blk-softirq
  block: Remove useless IPI struct initialization
  ...
2014-04-01 19:19:15 -07:00
Linus Torvalds 9d919e8d5b Merge branch 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "PREPARE_[DELAYED_]WORK() were used to change the work function of work
  items without fully reinitializing it; however, this makes workqueue
  consider the work item as a different one from before and allows the
  work item to start executing before the previous instance is finished
  which can lead to extremely subtle issues which are painful to debug.

  The interface has never been popular.  This pull request contains
  patches to remove existing usages and kill the interface.  As one of
  the changes was routed during the last devel cycle and another
  depended on a pending change in nvme, for-3.15 contains a couple merge
  commits.

  In addition, interfaces which were deprecated quite a while ago -
  __cancel_delayed_work() and WQ_NON_REENTRANT - are removed too"

* 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove deprecated WQ_NON_REENTRANT
  workqueue: Spelling s/instensive/intensive/
  workqueue: remove PREPARE_[DELAYED_]WORK()
  staging/fwserial: don't use PREPARE_WORK
  afs: don't use PREPARE_WORK
  nvme: don't use PREPARE_WORK
  usb: don't use PREPARE_DELAYED_WORK
  floppy: don't use PREPARE_[DELAYED_]WORK
  ps3-vuart: don't use PREPARE_WORK
  wireless/rt2x00: don't use PREPARE_WORK in rt2800usb.c
  workqueue: Remove deprecated __cancel_delayed_work()
2014-03-31 15:08:51 -07:00
Linus Torvalds 0f2776e615 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fix from Sage Weil:
 "This drops a bad assert that a few users have been hitting but we've
  only recently been able to track down"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: drop an unsafe assertion
2014-03-29 15:00:27 -07:00
Alex Elder 638c323c4d rbd: drop an unsafe assertion
Olivier Bonvalet reported having repeated crashes due to a failed
assertion he was hitting in rbd_img_obj_callback():

    Assertion failure in rbd_img_obj_callback() at line 2165:
	rbd_assert(which >= img_request->next_completion);

With a lot of help from Olivier with reproducing the problem
we were able to determine the object and image requests had
already been completed (and often freed) at the point the
assertion failed.

There was a great deal of discussion on the ceph-devel mailing list
about this.  The problem only arose when there were two (or more)
object requests in an image request, and the problem was always
seen when the second request was being completed.

The problem is due to a race in the window between setting the
"done" flag on an object request and checking the image request's
next completion value.  When the first object request completes, it
checks to see if its successor request is marked "done", and if
so, that request is also completed.  In the process, the image
request's next_completion value is updated to reflect that both
the first and second requests are completed.  By the time the
second request is able to check the next_completion value, it
has been set to a value *greater* than its own "which" value,
which caused an assertion to fail.

Fix this problem by skipping over any completion processing
unless the completing object request is the next one expected.
Test only for inequality (not >=), and eliminate the bad
assertion.

Tested-by: Olivier Bonvalet <ob@daevel.fr>
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-03-29 10:38:14 -07:00
Matthew Wilcox 6eb0d698ef NVMe: Replace DEFINE_PCI_DEVICE_TABLE
Checkpatch has started warning against using DEFINE_PCI_DEVICE_TABLE,
so replace it.  Also update the copyright date and bump the module
version number to 0.9.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-03-24 10:11:22 -04:00
Keith Busch ddcb776286 NVMe: Fix divide-by-zero in nvme_trans_io_get_num_cmds
dev->max_hw_sectors may be zero to indicate the device has no limit on
the number of sectors.  nvme_trans_do_nvme_io() should use the software
limit, since this is guaranteed to be non-zero.

Reported-by: Mundu <mundu2510@gmail.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-03-24 10:03:56 -04:00
Keith Busch 4f5099af4f NVMe: IOCTL path RCU protect queue access
This adds rcu protected access to a queue in the nvme IOCTL path
to fix potential races between a surprise removal and queue usage in
nvme_submit_sync_cmd. The fix holds the rcu_read_lock() here to prevent
the nvme_queue from freeing while this path is executing so it can't
sleep, and so this path will no longer wait for a available command
id should they all be in use at the time a passthrough IOCTL request
is received.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-03-24 08:54:40 -04:00
Keith Busch 5a92e700af NVMe: RCU protected access to io queues
This adds rcu protected access to nvme_queue to fix a race between a
surprise removal freeing the queue and a thread with open reference on
a NVMe block device using that queue.

The queues do not need to be rcu protected during the initialization or
shutdown parts, so I've added a helper function for raw deferencing
to get around the sparse errors.

There is still a hole in the IOCTL path for the same problem, which is
fixed in a subsequent patch.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-03-24 08:45:57 -04:00