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4440 commits

Author SHA1 Message Date
Linus Torvalds
10f3291a1d Merge branch 'akpm' (fixes from Andrew Morton)
Merge patches from Andrew Morton:
 "22 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
  kexec: purgatory: add clean-up for purgatory directory
  Documentation/kdump/kdump.txt: add ARM description
  flush_icache_range: export symbol to fix build errors
  tools: selftests: fix build issue with make kselftests target
  ocfs2: quorum: add a log for node not fenced
  ocfs2: o2net: set tcp user timeout to max value
  ocfs2: o2net: don't shutdown connection when idle timeout
  ocfs2: do not write error flag to user structure we cannot copy from/to
  x86/purgatory: use approprate -m64/-32 build flag for arch/x86/purgatory
  drivers/rtc/rtc-s5m.c: re-add support for devices without irq specified
  xattr: fix check for simultaneous glibc header inclusion
  kexec: remove CONFIG_KEXEC dependency on crypto
  kexec: create a new config option CONFIG_KEXEC_FILE for new syscall
  x86,mm: fix pte_special versus pte_numa
  hugetlb_cgroup: use lockdep_assert_held rather than spin_is_locked
  mm/zpool: use prefixed module loading
  zram: fix incorrect stat with failed_reads
  lib: turn CONFIG_STACKTRACE into an actual option.
  mm: actually clear pmd_numa before invalidating
  memblock, memhotplug: fix wrong type in memblock_find_in_range_node().
  ...
2014-08-29 16:28:29 -07:00
Chao Yu
0cf1e9d6c3 zram: fix incorrect stat with failed_reads
Since we allocate a temporary buffer in zram_bvec_read to handle partial
page operations in commit 924bd88d70 ("Staging: zram: allow partial
page operations"), our ->failed_reads value may be incorrect as we do
not increase its value when failing to allocate the temporary buffer.

Let's fix this issue and correct the annotation of failed_reads.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-29 16:28:16 -07:00
Dmitry Monakhov
aeac318194 brd: add ram disk visibility option
Currenly ram disk is not visiable inside /proc/partitions. This was
done for compatibility reasons here: 53978d0a7a. But some utilities
expect disk presents in /proc/partitions.
Let's add module's option and let's administrator chose visibility behaviour.
By default, old behaviour preserved.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-08-21 20:42:01 -05:00
Michal Simek
ffb5db73eb block: systemace: Remove .owner field for driver
There is no need to init .owner field.

Based on the patch from Peter Griffin <peter.griffin@linaro.org>
"mmc: remove .owner field for drivers using module_platform_driver"

This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway."

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-08-21 20:37:54 -05:00
Linus Torvalds
a11c5c9ef6 PCI changes for the v3.17 merge window (part 2):
Miscellaneous
     - Remove DEFINE_PCI_DEVICE_TABLE macro use (Benoit Taine)
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Merge tag 'pci-v3.17-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull DEFINE_PCI_DEVICE_TABLE removal from Bjorn Helgaas:
 "Part two of the PCI changes for v3.17:

    - Remove DEFINE_PCI_DEVICE_TABLE macro use (Benoit Taine)

  It's a mechanical change that removes uses of the
  DEFINE_PCI_DEVICE_TABLE macro.  I waited until later in the merge
  window to reduce conflicts, but it's possible you'll still see a few"

* tag 'pci-v3.17-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use
2014-08-14 18:10:33 -06:00
Linus Torvalds
d429a3639c Merge branch 'for-3.17/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe:
 "Nothing out of the ordinary here, this pull request contains:

   - A big round of fixes for bcache from Kent Overstreet, Slava Pestov,
     and Surbhi Palande.  No new features, just a lot of fixes.

   - The usual round of drbd updates from Andreas Gruenbacher, Lars
     Ellenberg, and Philipp Reisner.

   - virtio_blk was converted to blk-mq back in 3.13, but now Ming Lei
     has taken it one step further and added support for actually using
     more than one queue.

   - Addition of an explicit SG_FLAG_Q_AT_HEAD for block/bsg, to
     compliment the the default behavior of adding to the tail of the
     queue.  From Douglas Gilbert"

* 'for-3.17/drivers' of git://git.kernel.dk/linux-block: (86 commits)
  bcache: Drop unneeded blk_sync_queue() calls
  bcache: add mutex lock for bch_is_open
  bcache: Correct printing of btree_gc_max_duration_ms
  bcache: try to set b->parent properly
  bcache: fix memory corruption in init error path
  bcache: fix crash with incomplete cache set
  bcache: Fix more early shutdown bugs
  bcache: fix use-after-free in btree_gc_coalesce()
  bcache: Fix an infinite loop in journal replay
  bcache: fix crash in bcache_btree_node_alloc_fail tracepoint
  bcache: bcache_write tracepoint was crashing
  bcache: fix typo in bch_bkey_equal_header
  bcache: Allocate bounce buffers with GFP_NOWAIT
  bcache: Make sure to pass GFP_WAIT to mempool_alloc()
  bcache: fix uninterruptible sleep in writeback thread
  bcache: wait for buckets when allocating new btree root
  bcache: fix crash on shutdown in passthrough mode
  bcache: fix lockdep warnings on shutdown
  bcache allocator: send discards with correct size
  bcache: Fix to remove the rcu_sched stalls.
  ...
2014-08-14 09:10:21 -06:00
Linus Torvalds
8d2d441ac4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph updates from Sage Weil:
 "There is a lot of refactoring and hardening of the libceph and rbd
  code here from Ilya that fix various smaller bugs, and a few more
  important fixes with clone overlap.  The main fix is a critical change
  to the request_fn handling to not sleep that was exposed by the recent
  mutex changes (which will also go to the 3.16 stable series).

  Yan Zheng has several fixes in here for CephFS fixing ACL handling,
  time stamps, and request resends when the MDS restarts.

  Finally, there are a few cleanups from Himangi Saraogi based on
  Coccinelle"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (39 commits)
  libceph: set last_piece in ceph_msg_data_pages_cursor_init() correctly
  rbd: remove extra newlines from rbd_warn() messages
  rbd: allocate img_request with GFP_NOIO instead GFP_ATOMIC
  rbd: rework rbd_request_fn()
  ceph: fix kick_requests()
  ceph: fix append mode write
  ceph: fix sizeof(struct tYpO *) typo
  ceph: remove redundant memset(0)
  rbd: take snap_id into account when reading in parent info
  rbd: do not read in parent info before snap context
  rbd: update mapping size only on refresh
  rbd: harden rbd_dev_refresh() and callers a bit
  rbd: split rbd_dev_spec_update() into two functions
  rbd: remove unnecessary asserts in rbd_dev_image_probe()
  rbd: introduce rbd_dev_header_info()
  rbd: show the entire chain of parent images
  ceph: replace comma with a semicolon
  rbd: use rbd_segment_name_free() instead of kfree()
  ceph: check zero length in ceph_sync_read()
  ceph: reset r_resend_mds after receiving -ESTALE
  ...
2014-08-13 17:43:29 -06:00
Benoit Taine
9baa3c34ac PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use
We should prefer `struct pci_device_id` over `DEFINE_PCI_DEVICE_TABLE` to
meet kernel coding style guidelines.  This issue was reported by checkpatch.

A simplified version of the semantic patch that makes this change is as
follows (http://coccinelle.lip6.fr/):

// <smpl>

@@
identifier i;
declarer name DEFINE_PCI_DEVICE_TABLE;
initializer z;
@@

- DEFINE_PCI_DEVICE_TABLE(i)
+ const struct pci_device_id i[]
= z;

// </smpl>

[bhelgaas: add semantic patch]
Signed-off-by: Benoit Taine <benoit.taine@lip6.fr>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-08-12 12:15:14 -06:00
Joe Perches
a5bbf6160c block: use pci_zalloc_consistent
Remove the now unnecessary memset too.

Signed-off-by: Joe Perches <joe@perches.com>
Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:28 -07:00
Ilya Dryomov
9584d50826 rbd: remove extra newlines from rbd_warn() messages
rbd_warn() string should be a single line - rbd_warn() appends \n.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-08-07 16:01:09 +04:00
Ilya Dryomov
7a716aac01 rbd: allocate img_request with GFP_NOIO instead GFP_ATOMIC
Now that rbd_img_request_create() is called from work functions, no
need to use GFP_ATOMIC.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-08-07 16:00:52 +04:00
Ilya Dryomov
bc1ecc65a2 rbd: rework rbd_request_fn()
While it was never a good idea to sleep in request_fn(), commit
34c6bc2c91 ("locking/mutexes: Add extra reschedule point") made it
a *bad* idea.  mutex_lock() since 3.15 may reschedule *before* putting
task on the mutex wait queue, which for tasks in !TASK_RUNNING state
means block forever.  request_fn() may be called with !TASK_RUNNING on
the way to schedule() in io_schedule().

Offload request handling to a workqueue, one per rbd device, to avoid
calling blocking primitives from rbd_request_fn().

Fixes: http://tracker.ceph.com/issues/8818

Cc: stable@vger.kernel.org # 3.16, needs backporting for 3.15
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Tested-by: Eric Eastman <eric0e@aol.com>
Tested-by: Greg Wilson <greg.wilson@keepertech.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-08-07 14:56:20 +04:00
Weijie Yang
d2d5e762c8 zram: replace global tb_lock with fine grain lock
Currently, we use a rwlock tb_lock to protect concurrent access to the
whole zram meta table.  However, according to the actual access model,
there is only a small chance for upper user to access the same
table[index], so the current lock granularity is too big.

The idea of optimization is to change the lock granularity from whole
meta table to per table entry (table -> table[index]), so that we can
protect concurrent access to the same table[index], meanwhile allow the
maximum concurrency.

With this in mind, several kinds of locks which could be used as a
per-entry lock were tested and compared:

Test environment:
x86-64 Intel Core2 Q8400, system memory 4GB, Ubuntu 12.04,
kernel v3.15.0-rc3 as base, zram with 4 max_comp_streams LZO.

iozone test:
iozone -t 4 -R -r 16K -s 200M -I +Z
(1GB zram with ext4 filesystem, take the average of 10 tests, KB/s)

      Test       base      CAS    spinlock    rwlock   bit_spinlock
-------------------------------------------------------------------
 Initial write  1381094   1425435   1422860   1423075   1421521
       Rewrite  1529479   1641199   1668762   1672855   1654910
          Read  8468009  11324979  11305569  11117273  10997202
       Re-read  8467476  11260914  11248059  11145336  10906486
  Reverse Read  6821393   8106334   8282174   8279195   8109186
   Stride read  7191093   8994306   9153982   8961224   9004434
   Random read  7156353   8957932   9167098   8980465   8940476
Mixed workload  4172747   5680814   5927825   5489578   5972253
  Random write  1483044   1605588   1594329   1600453   1596010
        Pwrite  1276644   1303108   1311612   1314228   1300960
         Pread  4324337   4632869   4618386   4457870   4500166

To enhance the possibility of access the same table[index] concurrently,
set zram a small disksize(10MB) and let threads run with large loop
count.

fio test:
fio --bs=32k --randrepeat=1 --randseed=100 --refill_buffers
--scramble_buffers=1 --direct=1 --loops=3000 --numjobs=4
--filename=/dev/zram0 --name=seq-write --rw=write --stonewall
--name=seq-read --rw=read --stonewall --name=seq-readwrite
--rw=rw --stonewall --name=rand-readwrite --rw=randrw --stonewall
(10MB zram raw block device, take the average of 10 tests, KB/s)

    Test     base     CAS    spinlock    rwlock  bit_spinlock
-------------------------------------------------------------
seq-write   933789   999357   1003298    995961   1001958
 seq-read  5634130  6577930   6380861   6243912   6230006
   seq-rw  1405687  1638117   1640256   1633903   1634459
  rand-rw  1386119  1614664   1617211   1609267   1612471

All the optimization methods show a higher performance than the base,
however, it is hard to say which method is the most appropriate.

On the other hand, zram is mostly used on small embedded system, so we
don't want to increase any memory footprint.

This patch pick the bit_spinlock method, pack object size and page_flag
into an unsigned long table.value, so as to not increase any memory
overhead on both 32-bit and 64-bit system.

On the third hand, even though different kinds of locks have different
performances, we can ignore this difference, because: if zram is used as
zram swapfile, the swap subsystem can prevent concurrent access to the
same swapslot; if zram is used as zram-blk for set up filesystem on it,
the upper filesystem and the page cache also prevent concurrent access
of the same block mostly.  So we can ignore the different performances
among locks.

Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Signed-off-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>
2014-08-06 18:01:23 -07:00
Minchan Kim
023b409f9d zram: use size_t instead of u16
Some architectures (eg, hexagon and PowerPC) could use PAGE_SHIFT of 16
or more.  In these cases u16 is not sufficiently large to represent a
compressed page's size so use size_t.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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>
2014-08-06 18:01:23 -07:00
Sergey Senozhatsky
a830eff749 zram: remove unused SECTOR_SIZE define
Drop SECTOR_SIZE define, because it's not used.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Weijie Yang <weijie.yang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Sergey Senozhatsky
cb8f2eec3c zram: rename struct table' to zram_table_entry'
Andrew Morton has recently noted that `struct table' actually represents
table entry and, thus, should be renamed.  Rename to `zram_table_entry'.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Weijie Yang <weijie.yang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:22 -07:00
Ilya Dryomov
4d9b67cddd rbd: take snap_id into account when reading in parent info
If we are mapping a snapshot, we must read in the parent_overlap value
of that snapshot instead of that of the base image.  Not doing so may
in particular result in us returning zeros instead of user data:

    # cat overlap-snap.sh
    #!/bin/bash
    rbd create --size 10 --image-format 2 foo
    FOO_DEV=$(rbd map foo)
    dd if=/dev/urandom of=$FOO_DEV bs=1M &>/dev/null
    echo "Base image"
    dd if=$FOO_DEV bs=1 count=16 skip=$(((4 << 20) - 8)) 2>/dev/null | xxd
    rbd snap create foo@snap
    rbd snap protect foo@snap
    rbd clone foo@snap bar
    rbd snap create bar@snap
    BAR_DEV=$(rbd map bar@snap)
    echo "Snapshot"
    dd if=$BAR_DEV bs=1 count=16 skip=$(((4 << 20) - 8)) 2>/dev/null | xxd
    rbd resize --allow-shrink --size 4 bar
    echo "Snapshot after base image resize"
    dd if=$BAR_DEV bs=1 count=16 skip=$(((4 << 20) - 8)) 2>/dev/null | xxd

    # ./overlap-snap.sh
    Base image
    0000000: e781 e33b d34b 2225 6034 2845 a2e3 36ed  ...;.K"%`4(E..6.
    Snapshot
    0000000: e781 e33b d34b 2225 6034 2845 a2e3 36ed  ...;.K"%`4(E..6.
    Resizing image: 100% complete...done.
    Snapshot after base image resize
    0000000: e781 e33b d34b 2225 0000 0000 0000 0000  ...;.K"%........

Even though bar@snap is taken with the old bar parent_overlap (8M),
reads from bar@snap beyond the new bar parent_overlap (4M) return
zeroes.  Fix it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:16:50 +04:00
Ilya Dryomov
e8f59b595d rbd: do not read in parent info before snap context
Currently rbd_dev_v2_header_info() reads in parent info before the snap
context is read in.  This is wrong, because we may need to look at the
the parent_overlap value of the snapshot instead of that of the base
image, for example when mapping a snapshot - see next commit.  (When
mapping a snapshot, all we got is its name and we need the snap context
to translate that name into an id to know which parent info to look
for.)

The approach taken here is to make sure rbd_dev_v2_parent_info() is
called after the snap context has been read in.  The other approach
would be to add a parent_overlap field to struct rbd_mapping and
maintain it the same way rbd_mapping::size is maintained.  The reason
I chose the first approach is that the value of keeping around both
base image values and the actual mapping values is unclear to me.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:16:14 +04:00
Ilya Dryomov
5ff1108ccc rbd: update mapping size only on refresh
There is no sense in trying to update the mapping size before it's even
been set.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:58 +04:00
Ilya Dryomov
52bb1f9bed rbd: harden rbd_dev_refresh() and callers a bit
Recently discovered watch/notify problems showed that we really can't
ignore errors in anything refresh related.  Alas, currently there is
not much we can do in response to those errors, except print warnings.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:44 +04:00
Ilya Dryomov
0407759971 rbd: split rbd_dev_spec_update() into two functions
rbd_dev_spec_update() has two modes of operation, with nothing in
common between them.  Split it into two functions, one for each mode
and make our expectations more clear.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:35 +04:00
Ilya Dryomov
7626eb7d82 rbd: remove unnecessary asserts in rbd_dev_image_probe()
spec->image_id assert doesn't buy us much and image_format is asserted
in rbd_dev_header_name() and rbd_dev_header_info() anyway.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:18 +04:00
Ilya Dryomov
a720ae0901 rbd: introduce rbd_dev_header_info()
A wrapper around rbd_dev_v{1,2}_header_info() to reduce duplication.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:00 +04:00
Ilya Dryomov
ff96128fb0 rbd: show the entire chain of parent images
Make /sys/bus/rbd/devices/<id>/parent show the entire chain of parent
images.  While at it, kernel sprintf() doesn't return negative values,
casting to unsigned long long is no longer necessary and there is no
good reason to split into multiple sprintf() calls.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:14:27 +04:00
Himangi Saraogi
7d5079aa8b rbd: use rbd_segment_name_free() instead of kfree()
Free memory allocated using kmem_cache_zalloc using kmem_cache_free
rather than kfree. The helper rbd_segment_name_free does the job here.
Its position is shifted above the calling function.

The Coccinelle semantic patch that detects this change is as follows:

// <smpl>
@@
expression x,E,c;
@@

 x = \(kmem_cache_alloc\|kmem_cache_zalloc\|kmem_cache_alloc_node\)(c,...)
 ... when != x = E
     when != &x
?-kfree(x)
+kmem_cache_free(c,x)
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-07-24 11:57:27 +04:00
Minchan Kim
b4c5c60920 zram: avoid lockdep splat by revalidate_disk
Sasha reported lockdep warning [1] introduced by [2].

It could be fixed by doing disk revalidation out of the init_lock.  It's
okay because disk capacity change is protected by init_lock so that
revalidate_disk always sees up-to-date value so there is no race.

[1] https://lkml.org/lkml/2014/7/3/735
[2] zram: revalidate disk after capacity change

Fixes 2e32baea46 ("zram: revalidate disk after capacity change").

Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: "Alexander E. Patrakov" <patrakov@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-23 15:10:54 -07:00
Dan Carpenter
bf0d6e4a11 drbd: silence underflow warning in read_in_block()
My static checker warns that "data_size" could be negative and underflow
the limit check.  The code looks suspicious but I don't know if it is a
real bug.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:23 +02:00
Lars Ellenberg
1e39152fea drbd: implicitly truncate cpu-mask
Don't error out with misleading "out of memory"
if the cpu-mask has more bits set than there are CPUs.
Just truncate to nr_cpu_ids implicitly.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:22 +02:00
Lars Ellenberg
193cb00ce3 drbd: drop spurious parameters from _drbd_md_sync_page_io
size is always 4096,
page is always device->md_io.page.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:22 +02:00
Lars Ellenberg
f5b90b6bf0 drbd: resync should only lock out specific ranges
During resync, if we need to block some specific incoming write because
of active resync requests to that same range, we potentially caused
*all* new application writes (to "cold" activity log extents) to block
until this one request has been processed.

Improve the do_submit() logic to
 * grab all incoming requests to some "incoming" list
 * process this list
   - move aside requests that are blocked by resync
   - prepare activity log transactions,
   - commit transactions and submit corresponding requests
   - if there are remaining requests that only wait for
     activity log extents to become free, stop the fast path
     (mark activity log as "starving")
   - iterate until no more requests are waiting for the activity log,
     but all potentially remaining requests are only blocked by resync
 * only then grab new incoming requests

That way, very busy IO on currently "hot" activity log extents cannot
starve scattered IO to "cold" extents. And blocked-by-resync requests
are processed once resync traffic on the affected region has ceased,
without blocking anything else.

The only blocking mode left is when we cannot start requests to "cold"
extents because all currently "hot" extents are actually used.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:21 +02:00
Lars Ellenberg
cc356f85bb drbd: debugfs: add per device data_gen_id
The data generation identifiers used to be exposed via sysfs
at /sys/block/drbdX/drbd/meta_data/data_gen_id (out-of-tree),
for advanced policy scripting.
Bring that information over to debugfs.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:21 +02:00
Lars Ellenberg
3d299f48a9 drbd: debugfs: add per connection oldest requests
Information of former /sys/block/drbdX/drbd/oldest_requests
is already with higher detail in these files:
 debugfs/drbd/resource/$name/in_flight_summary,
 debugfs/drbd/resource/$name/volumes/$vnr/oldest_requests

This patch adds
 debugfs/drbd/resource/$name/connections/peer/oldest_requests

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:20 +02:00
Lars Ellenberg
b44e1184fc drbd: debugfs: add version tag to debugfs files
Make the first line of debugfs files a version number,
starting now with "v: 0".

If we change content of presentation, we will bump that.
Monitoring or diagnostic scritps that may parse these files
can then easily know when they need to be reviewed.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:19 +02:00
Lars Ellenberg
54e6fc38e8 drbd: debugfs: add per volume oldest_requests
Show oldest requests
 * pending master bio completion and,
 * if different, local disk bio completion.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:19 +02:00
Lars Ellenberg
944410e97c drbd: debugfs: add callback_history
Add a per-connection worker thread callback_history
with timing details, call site and callback function.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:18 +02:00
Lars Ellenberg
f418815f7a drbd: debugfs: Add in_flight_summary
* Add details about pending meta data operations to in_flight_summary.

* Report number of requests waiting for activity log transactions.

* timing details of peer_requests to in_flight_summary.

* FLUSH details
  DRBD devides the incoming request stream into "epochs",
  in which peers are allowed to re-order writes independendly.

  These epochs are separated by P_BARRIER on the replication link.
  Such barrier packets, depending on configuration, may cause
  the receiving side to drain the lower level device request queues
  and call blkdev_issue_flush().

  This is known to be an other major source of latency in DRBD.

  Track timing details of calls to blkdev_issue_flush(),
  and add them to in_flight_summary.

* data socket stats
  To be able to diagnose bottlenecks and root causes of "slow" IO on DRBD,
  it is useful to see network buffer stats along with the timing details of
  requests, peer requests, and meta data IO.

* pending bitmap IO timing details to in_flight_summary.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:17 +02:00
Lars Ellenberg
4a521cca9b drbd: debugfs: deal with destructor racing with open of debugfs file
Try to close the race between open() and debugfs_remove_recursive()
from inside an object destructor.
Once open succeeds, the object should stay around.
Open should not succeed if the object has already reached its destructor.

This may be overkill, but to make that happen, we check for existence of
a parent directory, "stale-ness" of "this" dentry, and serialize
kref_get_unless_zero() on the outermost object relevant for this file
with d_delete() on this dentry (using the parent's i_mutex).

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:17 +02:00
Lars Ellenberg
db1866ffee drbd: debugfs: add in_flight_summary data
To help diagnosing "high latency" or "hung" IO situations on DRBD,
present per drbd resource group a summary of operations currently in progress.

First item is a list of oldest drbd_request objects
waiting for various things:
 * still being prepared
 * waiting for activity log transaction
 * waiting for local disk
 * waiting to be sent
 * waiting for peer acknowledgement ("receive ack", "write ack")
 * waiting for peer epoch acknowledgement ("barrier ack")

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:16 +02:00
Lars Ellenberg
4d3d5aa83a drbd: debugfs: add basic hierarchy
Add new debugfs hierarchy /sys/kernel/debug/
  drbd/
    resources/
      $resource_name/connections/peer/$volume_number/
      $resource_name/volumes/$volume_number/
    minors/$minor_number -> ../resources/$resource_name/volumes/$volume_number/

Followup commits will populate this hierarchy with files containing
statistics, diagnostic information and some attribute data.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:16 +02:00
Lars Ellenberg
4ce4926683 drbd: track details of bitmap IO
Track start and submit time of bitmap operations, and
add pending bitmap IO contexts to a new pending_bitmap_io list.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:15 +02:00
Lars Ellenberg
c5a2c1509e drbd: register peer requests on read_ee early
Initialize peer_request with timestamp and proper empty list head.
Add peer_request to list early, so debugfs can find this request and
report it as "preparing", even if we sleep before we actually submit it.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:14 +02:00
Lars Ellenberg
21ae5d7f95 drbd: track timing details of peer_requests
To be able to present timing details in debugfs,
we need to track preparation/submit times of peer requests.

Track peer request flags early,
before they are put on the epoch_entry lists.

Waiting for activity log transactions may be a major latency factor.
We want to be able to present the peer_request state accurately in
debugfs, and what it is waiting for.

Consistently mark/unmark peer requests with EE_CALL_AL_COMPLETE_IO.
Set it only *after* calling drbd_al_begin_io(),
clear it as soon as we call drbd_al_complete_io().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:14 +02:00
Lars Ellenberg
ad3fee7900 drbd: improve throttling decisions of background resynchronisation
Background resynchronisation does some "side-stepping", or throttles
itself, if it detects application IO activity, and the current resync
rate estimate is above the configured "cmin-rate".

What was not detected: if there is no application IO,
because it blocks on activity log transactions.

Introduce a new atomic_t ap_actlog_cnt, tracking such blocked requests,
and count non-zero as application IO activity.
This counter is exposed at proc_details level 2 and above.

Also make sure to release the currently locked resync extent
if we side-step due to such voluntary throttling.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:13 +02:00
Lars Ellenberg
7753a4c17f drbd: add caching oldest request pointers for replication stages
A request that is to be shipped to the peer goes through a few stages:
- queued
- sent, waiting for ack
- ack received, waiting for "barrier ack", which is re-order epoch being
  closed on the peer by acknowledging a "cache flush" equivalent
  on the lower level device.

In the later two stages, depending on protocol, we may have already
completed this request to the upper layers, so it won't be found anymore
on device->pending_master_completion[] lists.

Track the oldest request yet to be sent (req_next), the oldest not yet
acknowledged (req_ack_pending) and the oldest "still waiting for
something from the peer" (req_not_net_done), doing short list walks on
the transfer log to find the next pending one whenever such a request
makes progress.

Now we have a fast way to look up the oldest requests,
don't do a transfer log walk every time.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:12 +02:00
Lars Ellenberg
844a6ae735 drbd: add lists to find oldest pending requests
Adding requests to per-device fifo lists as soon as possible after
allocating them leaves a simple list_first_entry_or_null() to find the
oldest request, regardless what it is still waiting for.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:12 +02:00
Lars Ellenberg
e5f891b223 drbd: gather detailed timing statistics for drbd_requests
Record (in jiffies) how much time a request spends in which stages.
Followup commits will use and present this additional timing information
so we can better locate and tackle the root causes of latency spikes,
or present the backlog for asynchronous replication.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:11 +02:00
Lars Ellenberg
e37d2438d8 drbd: track meta data IO intent, start and submit time
For diagnostic purposes, track intent, start time
and latest submit time of meta data IO.

Move separate members from struct drbd_device
into the embeded struct drbd_md_io.
s/md_io_(page|in_use)/md_io.\1/

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:10 +02:00
Lars Ellenberg
a8ba0d6069 drbd: fix drbd_destroy_device reference count updates
drbd_destroy_device means to give up reference counts
on the connection(s) reachable via the peer_device(s).

It must not do that by iterating via device->resource->connections,
resource and connections may have already been disassociated
by drbd_free_resource, and we'd leak connection refs.

Instead, iterate via device->peer_devices->connection.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:10 +02:00
Lars Ellenberg
c2258ffc56 drbd: poison free'd device, resource and connection structs
Now that we have additional asynchronous kref_get/kref_put
via debugfs, make sure we catch access after free.

Poison struct drbd_device, drbd_connection and drbd_resource
before kfree() with 0xfd, 0xfc, and 0xf2, respectively.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:09 +02:00
Lars Ellenberg
45d2933c92 drbd: also keep track of trim -> zero-out fallback peer_requests
To be able to find and present such zero-out fallback peer_requests
in debugfs, we add those to "active_ee", once that list drained.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:09 +02:00