Commit Graph

189856 Commits

Author SHA1 Message Date
Vivek Goyal e5ff082e8a blkio: Fix another BUG_ON() crash due to cfqq movement across groups
o Once in a while, I was hitting a BUG_ON() in blkio code. empty_time was
  assuming that upon slice expiry, group can't be marked empty already (except
  forced dispatch).

  But this assumption is broken if cfqq can move (group_isolation=0) across
  groups after receiving a request.

  I think most likely in this case we got a request in a cfqq and accounted
  the rq in one group, later while adding the cfqq to tree, we moved the queue
  to a different group which was already marked empty and after dispatch from
  slice we found group already marked empty and raised alarm.

  This patch does not error out if group is already marked empty. This can
  introduce some empty_time stat error only in case of group_isolation=0. This
  is better than crashing. In case of group_isolation=1 we should still get
  same stats as before this patch.

[  222.308546] ------------[ cut here ]------------
[  222.309311] kernel BUG at block/blk-cgroup.c:236!
[  222.309311] invalid opcode: 0000 [#1] SMP
[  222.309311] last sysfs file: /sys/devices/virtual/block/dm-3/queue/scheduler
[  222.309311] CPU 1
[  222.309311] Modules linked in: dm_round_robin dm_multipath qla2xxx scsi_transport_fc dm_zero dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]
[  222.309311]
[  222.309311] Pid: 4780, comm: fio Not tainted 2.6.34-rc4-blkio-config #68 0A98h/HP xw8600 Workstation
[  222.309311] RIP: 0010:[<ffffffff8121ad88>]  [<ffffffff8121ad88>] blkiocg_set_start_empty_time+0x50/0x83
[  222.309311] RSP: 0018:ffff8800ba6e79f8  EFLAGS: 00010002
[  222.309311] RAX: 0000000000000082 RBX: ffff8800a13b7990 RCX: ffff8800a13b7808
[  222.309311] RDX: 0000000000002121 RSI: 0000000000000082 RDI: ffff8800a13b7a30
[  222.309311] RBP: ffff8800ba6e7a18 R08: 0000000000000000 R09: 0000000000000001
[  222.309311] R10: 000000000002f8c8 R11: ffff8800ba6e7ad8 R12: ffff8800a13b78ff
[  222.309311] R13: ffff8800a13b7990 R14: 0000000000000001 R15: ffff8800a13b7808
[  222.309311] FS:  00007f3beec476f0(0000) GS:ffff880001e40000(0000) knlGS:0000000000000000
[  222.309311] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  222.309311] CR2: 000000000040e7f0 CR3: 00000000a12d5000 CR4: 00000000000006e0
[  222.309311] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  222.309311] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  222.309311] Process fio (pid: 4780, threadinfo ffff8800ba6e6000, task ffff8800b3d6bf00)
[  222.309311] Stack:
[  222.309311]  0000000000000001 ffff8800bab17a48 ffff8800bab17a48 ffff8800a13b7800
[  222.309311] <0> ffff8800ba6e7a68 ffffffff8121da35 ffff880000000001 00ff8800ba5c5698
[  222.309311] <0> ffff8800ba6e7a68 ffff8800a13b7800 0000000000000000 ffff8800bab17a48
[  222.309311] Call Trace:
[  222.309311]  [<ffffffff8121da35>] __cfq_slice_expired+0x2af/0x3ec
[  222.309311]  [<ffffffff8121fd7b>] cfq_dispatch_requests+0x2c8/0x8e8
[  222.309311]  [<ffffffff8120f1cd>] ? spin_unlock_irqrestore+0xe/0x10
[  222.309311]  [<ffffffff8120fb1a>] ? blk_insert_cloned_request+0x70/0x7b
[  222.309311]  [<ffffffff81210461>] blk_peek_request+0x191/0x1a7
[  222.309311]  [<ffffffffa0002799>] dm_request_fn+0x38/0x14c [dm_mod]
[  222.309311]  [<ffffffff810ae61f>] ? sync_page_killable+0x0/0x35
[  222.309311]  [<ffffffff81210fd4>] __generic_unplug_device+0x32/0x37
[  222.309311]  [<ffffffff81211274>] generic_unplug_device+0x2e/0x3c
[  222.309311]  [<ffffffffa00011a6>] dm_unplug_all+0x42/0x5b [dm_mod]
[  222.309311]  [<ffffffff8120ca37>] blk_unplug+0x29/0x2d
[  222.309311]  [<ffffffff8120ca4d>] blk_backing_dev_unplug+0x12/0x14
[  222.309311]  [<ffffffff81109a7a>] block_sync_page+0x35/0x39
[  222.309311]  [<ffffffff810ae616>] sync_page+0x41/0x4a
[  222.309311]  [<ffffffff810ae62d>] sync_page_killable+0xe/0x35
[  222.309311]  [<ffffffff8158aa59>] __wait_on_bit_lock+0x46/0x8f
[  222.309311]  [<ffffffff810ae4f5>] __lock_page_killable+0x66/0x6d
[  222.309311]  [<ffffffff81056f9c>] ? wake_bit_function+0x0/0x33
[  222.309311]  [<ffffffff810ae528>] lock_page_killable+0x2c/0x2e
[  222.309311]  [<ffffffff810afbc5>] generic_file_aio_read+0x361/0x4f0
[  222.309311]  [<ffffffff810ea044>] do_sync_read+0xcb/0x108
[  222.309311]  [<ffffffff811e42f7>] ? security_file_permission+0x16/0x18
[  222.309311]  [<ffffffff810ea6ab>] vfs_read+0xab/0x108
[  222.309311]  [<ffffffff810ea7c8>] sys_read+0x4a/0x6e
[  222.309311]  [<ffffffff81002b5b>] system_call_fastpath+0x16/0x1b
[  222.309311] Code: 58 01 00 00 00 48 89 c6 75 0a 48 83 bb 60 01 00 00 00 74 09 48 8d bb a0 00 00 00 eb 35 41 fe cc 74 0d f6 83 c0 01 00 00 04 74 04 <0f> 0b eb fe 48 89 75 e8 e8 be e0 de ff 66 83 8b c0 01 00 00 04
[  222.309311] RIP  [<ffffffff8121ad88>] blkiocg_set_start_empty_time+0x50/0x83
[  222.309311]  RSP <ffff8800ba6e79f8>
[  222.309311] ---[ end trace 32b4f71dffc15712 ]---

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Divyesh Shah <dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-26 19:25:11 +02:00
Vivek Goyal 7f1dc8a2d2 blkio: Fix blkio crash during rq stat update
blkio + cfq was crashing even when two sequential readers were put in two
separate cgroups (group_isolation=0).

The reason being that cfqq can migrate across groups based on its being
sync-noidle or not, it can happen that at request insertion time, cfqq
belonged to one cfqg and at request dispatch time, it belonged to root
group. In this case request stats per cgroup can go wrong and it also runs
into BUG_ON().

This patch implements rq stashing away a cfq group pointer and not relying
on cfqq->cfqg pointer alone for rq stat accounting.

[   65.163523] ------------[ cut here ]------------
[   65.164301] kernel BUG at block/blk-cgroup.c:117!
[   65.164301] invalid opcode: 0000 [#1] SMP
[   65.164301] last sysfs file: /sys/devices/pci0000:00/0000:00:05.0/0000:60:00.1/host9/rport-9:0-0/target9:0:0/9:0:0:2/block/sde/stat
[   65.164301] CPU 1
[   65.164301] Modules linked in: dm_round_robin dm_multipath qla2xxx scsi_transport_fc dm_zero dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]
[   65.164301]
[   65.164301] Pid: 4505, comm: fio Not tainted 2.6.34-rc4-blk-for-35 #34 0A98h/HP xw8600 Workstation
[   65.164301] RIP: 0010:[<ffffffff8121924f>]  [<ffffffff8121924f>] blkiocg_update_io_remove_stats+0x5b/0xaf
[   65.164301] RSP: 0018:ffff8800ba5a79e8  EFLAGS: 00010046
[   65.164301] RAX: 0000000000000096 RBX: ffff8800bb268d60 RCX: 0000000000000000
[   65.164301] RDX: ffff8800bb268eb8 RSI: 0000000000000000 RDI: ffff8800bb268e00
[   65.164301] RBP: ffff8800ba5a7a08 R08: 0000000000000064 R09: 0000000000000001
[   65.164301] R10: 0000000000079640 R11: ffff8800a0bd5bf0 R12: ffff8800bab4af01
[   65.164301] R13: ffff8800bab4af00 R14: ffff8800bb1d8928 R15: 0000000000000000
[   65.164301] FS:  00007f18f75056f0(0000) GS:ffff880001e40000(0000) knlGS:0000000000000000
[   65.164301] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   65.164301] CR2: 000000000040e7f0 CR3: 00000000ba52b000 CR4: 00000000000006e0
[   65.164301] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   65.164301] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   65.164301] Process fio (pid: 4505, threadinfo ffff8800ba5a6000, task ffff8800ba45ae80)
[   65.164301] Stack:
[   65.164301]  ffff8800ba5a7a08 ffff8800ba722540 ffff8800bab4af68 ffff8800bab4af68
[   65.164301] <0> ffff8800ba5a7a38 ffffffff8121d814 ffff8800ba722540 ffff8800bab4af68
[   65.164301] <0> ffff8800ba722540 ffff8800a08f6800 ffff8800ba5a7a68 ffffffff8121d8ca
[   65.164301] Call Trace:
[   65.164301]  [<ffffffff8121d814>] cfq_remove_request+0xe4/0x116
[   65.164301]  [<ffffffff8121d8ca>] cfq_dispatch_insert+0x84/0xe1
[   65.164301]  [<ffffffff8121e833>] cfq_dispatch_requests+0x767/0x8e8
[   65.164301]  [<ffffffff8120e524>] ? submit_bio+0xc3/0xcc
[   65.164301]  [<ffffffff810ad657>] ? sync_page_killable+0x0/0x35
[   65.164301]  [<ffffffff8120ea8d>] blk_peek_request+0x191/0x1a7
[   65.164301]  [<ffffffffa000109c>] ? dm_get_live_table+0x44/0x4f [dm_mod]
[   65.164301]  [<ffffffffa0002799>] dm_request_fn+0x38/0x14c [dm_mod]
[   65.164301]  [<ffffffff810ad657>] ? sync_page_killable+0x0/0x35
[   65.164301]  [<ffffffff8120f600>] __generic_unplug_device+0x32/0x37
[   65.164301]  [<ffffffff8120f8a0>] generic_unplug_device+0x2e/0x3c
[   65.164301]  [<ffffffffa00011a6>] dm_unplug_all+0x42/0x5b [dm_mod]
[   65.164301]  [<ffffffff8120b063>] blk_unplug+0x29/0x2d
[   65.164301]  [<ffffffff8120b079>] blk_backing_dev_unplug+0x12/0x14
[   65.164301]  [<ffffffff81108a82>] block_sync_page+0x35/0x39
[   65.164301]  [<ffffffff810ad64e>] sync_page+0x41/0x4a
[   65.164301]  [<ffffffff810ad665>] sync_page_killable+0xe/0x35
[   65.164301]  [<ffffffff81589027>] __wait_on_bit_lock+0x46/0x8f
[   65.164301]  [<ffffffff810ad52d>] __lock_page_killable+0x66/0x6d
[   65.164301]  [<ffffffff81055fd4>] ? wake_bit_function+0x0/0x33
[   65.164301]  [<ffffffff810ad560>] lock_page_killable+0x2c/0x2e
[   65.164301]  [<ffffffff810aebfd>] generic_file_aio_read+0x361/0x4f0
[   65.164301]  [<ffffffff810e906c>] do_sync_read+0xcb/0x108
[   65.164301]  [<ffffffff811e32a3>] ? security_file_permission+0x16/0x18
[   65.164301]  [<ffffffff810e96d3>] vfs_read+0xab/0x108
[   65.164301]  [<ffffffff810e97f0>] sys_read+0x4a/0x6e
[   65.164301]  [<ffffffff81002b5b>] system_call_fastpath+0x16/0x1b
[   65.164301] Code: 00 74 1c 48 8b 8b 60 01 00 00 48 85 c9 75 04 0f 0b eb fe 48 ff c9 48 89 8b 60 01 00 00 eb 1a 48 8b 8b 58 01 00 00 48 85 c9 75 04 <0f> 0b eb fe 48 ff c9 48 89 8b 58 01 00 00 45 84 e4 74 16 48 8b
[   65.164301] RIP  [<ffffffff8121924f>] blkiocg_update_io_remove_stats+0x5b/0xaf
[   65.164301]  RSP <ffff8800ba5a79e8>
[   65.164301] ---[ end trace 1b2b828753032e68 ]---

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-21 17:44:16 +02:00
Divyesh Shah 8d2a91f896 blkio: Initialize blkg->stats_lock for the root cfqg too
This fixes the lockdep warning reported by Gui Jianfeng.

Signed-off-by: Divyesh Shah <dpshah@google.com>
Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-16 08:10:51 +02:00
Divyesh Shah b6ac23af2c blkio: fix for modular blk-cgroup build
After merging the block tree, 20100414's linux-next build (x86_64
allmodconfig) failed like this:

ERROR: "get_gendisk" [block/blk-cgroup.ko] undefined!
ERROR: "sched_clock" [block/blk-cgroup.ko] undefined!

This happens because the two symbols aren't exported and hence not available
when blk-cgroup code is built as a module. I've tried to stay consistent with
the use of EXPORT_SYMBOL or EXPORT_SYMBOL_GPL with the other symbols in the
respective files.

Signed-off-by: Divyesh Shah <dpshah@google.com>
Acked-by: Gui Jianfeng <guijianfeng@cn.fujitsu.cn>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-15 08:54:59 +02:00
Richard Kennedy c0d97e9ca2 block: ensure jiffies wrap is handled correctly in blk_rq_timed_out_timer
blk_rq_timed_out_timer() relied on blk_add_timer() never returning a
timer value of zero, but commit 7838c15b8d
removed the code that bumped this value when it was zero.
Therefore when jiffies is near wrap we could get unlucky & not set the
timeout value correctly.

This patch uses a flag to indicate that the timeout value was set and so
handles jiffies wrap correctly, and it keeps all the logic in one
function so should be easier to maintain in the future.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-14 20:53:37 +02:00
Divyesh Shah 28baf44299 blkio: Fix compile errors
Fixes compile errors in blk-cgroup code for empty_time stat and a merge fix in
CFQ. The first error was when CONFIG_DEBUG_CFQ_IOSCHED is not set.

Signed-off-by: Divyesh Shah <dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-14 11:22:38 +02:00
Jens Axboe 4facdaec1c Merge branch 'master' into for-2.6.35
Conflicts:
	block/blk-cgroup.c
	block/cfq-iosched.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13 20:03:21 +02:00
Divyesh Shah a11cdaa7af block: Update to io-controller stats
Changelog from v1:
o Call blkiocg_update_idle_time_stats() at cfq_rq_enqueued() instead of at
  dispatch time.

Changelog from original patchset: (in response to Vivek Goyal's comments)
o group blkiocg_update_blkio_group_dequeue_stats() with other DEBUG functions
o rename blkiocg_update_set_active_queue_stats() to
  blkiocg_update_avg_queue_size_stats()
o s/request/io/ in blkiocg_update_request_add_stats() and
  blkiocg_update_request_remove_stats()
o Call cfq_del_timer() at request dispatch() instead of
  blkiocg_update_idle_time_stats()

Signed-off-by: Divyesh Shah<dpshah@google.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13 19:59:17 +02:00
Gui Jianfeng da69da184c io-controller: Document for blkio.weight_device
Here is the document for blkio.weight_device

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13 10:14:20 +02:00
Gui Jianfeng 34d0f179d6 io-controller: Add a new interface "weight_device" for IO-Controller
Currently, IO Controller makes use of blkio.weight to assign weight for
all devices. Here a new user interface "blkio.weight_device" is introduced to
assign different weights for different devices. blkio.weight becomes the
default value for devices which are not configured by "blkio.weight_device"

You can use the following format to assigned specific weight for a given
device:
#echo "major:minor weight" > blkio.weight_device

major:minor represents device number.

And you can remove weight for a given device as following:
#echo "major:minor 0" > blkio.weight_device

V1->V2 changes:
- use user interface "weight_device" instead of "policy" suggested by Vivek
- rename some struct suggested by Vivek
- rebase to 2.6-block "for-linus" branch
- remove an useless list_empty check pointed out by Li Zefan
- some trivial typo fix

V2->V3 changes:
- Move policy_*_node() functions up to get rid of forward declarations
- rename related functions by adding prefix "blkio_"

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13 10:14:20 +02:00
Linus Torvalds 0d0fb0f9c5 Linux 2.6.34-rc4 2010-04-12 18:41:35 -07:00
Linus Torvalds 64a8920fab Merge branch 'anonvma'
* anonvma:
  anonvma: when setting up page->mapping, we need to pick the _oldest_ anonvma
  anon_vma: clone the anon_vma chain in the right order
  vma_adjust: fix the copying of anon_vma chains
  Simplify and comment on anon_vma re-use for anon_vma_prepare()
2010-04-12 18:39:58 -07:00
Linus Torvalds 50b88c46f0 Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm: (21 commits)
  ARM: Fix ioremap_cached()/ioremap_wc() for SMP platforms
  ARM: 6043/1: AT91 slow-clock resume: Don't wait for a disabled PLL to lock
  ARM: 6031/1: fix Thumb-2 decompressor
  ARM: 6029/1: ep93xx: gpio.c: local functions should be static
  ARM: 6028/1: ARM: add MAINTAINERS for U300
  ARM: 6024/1: bcmring: fix missing down on semaphore in dma.c
  MXC: mach_armadillo5x0: Add USB Host support.
  ARM mach-mx3: duplicated include
  ARM mach-mx3: duplicated include
  imx31: add watchdog device on litekit board.
  imx3: Add watchdog platform device support
  MXC: mach-mx31_3ds: add support for freescale mc13783 power management device.
  MXC: mach-mx31_3ds: Add SPI1 device support.
  MXC: mach-mx31_3ds: Add support for on board NAND Flash.
  MXC: mach-mx31_3ds: Update variable names over recent mach name modification.
  imx31: fix parent clock for rtc
  i.MX51: remove NFC AXI static mapping
  i.MX51: determine silicon revision dynamically
  i.MX51: map TZIC dynamically
  i.MX51: Use correct clock for gpt
  ...
2010-04-12 18:37:34 -07:00
Linus Torvalds d6cf853d4d Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: make sure the chunk allocator doesn't create zero length chunks
  Btrfs: fix data enospc check overflow
2010-04-12 18:37:04 -07:00
Linus Torvalds 6a945f38be Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  quota: Fix possible dq_flags corruption
  quota: Hide warnings about writes to the filesystem before quota was turned on
  ext3: symlink must be handled via filesystem specific operation
  ext2: symlink must be handled via filesystem specific operation
2010-04-12 18:36:49 -07:00
Linus Torvalds 50fc88cb03 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6:
  udf: add speciffic ->setattr callback
  udf: potential integer overflow
2010-04-12 18:36:34 -07:00
Linus Torvalds 4505a49389 Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (36 commits)
  MIPS: Calculate proper ebase value for 64-bit kernels
  MIPS: Alchemy: DB1200: Remove custom wait implementation
  MIPS: Big Sur: Make defconfig more useful.
  MIPS: Fix __vmalloc() etc. on MIPS for non-GPL modules
  MIPS: Sibyte: Fix M3 TLB exception handler workaround.
  MIPS: BCM63xx: Fix build failure in board_bcm963xx.c
  MIPS: uasm: Add OR instruction.
  MIPS: Sibyte: Apply M3 workaround only on affected chip types and versions.
  MIPS: BCM63xx: Initialize gpio_out_low & out_high to current value at boot.
  MIPS: BCM63xx: Register SSB SPROM fallback in board's first stage callback
  MIPS: BCM63xx: Fix typo in cpu-feature-overrides file.
  MIPS: BCM63xx: Add support for second uart.
  MIPS: BCM63xx: Fix double gpio registration.
  MIPS: BCM63xx: Add DWVS0 board
  MIPS: BCM63xx: Add the RTA1025W-16 BCM6348-based board to suppported boards.
  MIPS: BCM63xx: Fix BCM6338 and BCM6345 gpio count
  MIPS: libgcc.h: Checkpatch cleanup
  MIPS: Loongson-2F: Flush the branch target history in BTB and RAS
  MIPS: Move signal trampolines off of the stack.
  MIPS: Preliminary VDSO
  ...
2010-04-12 18:36:11 -07:00
Linus Torvalds fedfb947b2 Merge branch 'for-2.6.34' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.34' of git://linux-nfs.org/~bfields/linux:
  svcrdma: RDMA support not yet compatible with RPC6
2010-04-12 18:34:56 -07:00
Linus Torvalds 44fa2b4bee Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix typo "numer" -> "number" in alloc.c
  nilfs2: Remove an uninitialization warning in nilfs_btree_propagate_v()
  nilfs2: fix a wrong type conversion in nilfs_ioctl()
2010-04-12 18:34:25 -07:00
Linus Torvalds ea90002b0f anonvma: when setting up page->mapping, we need to pick the _oldest_ anonvma
Otherwise we might be mapping in a page in a new mapping, but that page
(through the swapcache) would later be mapped into an old mapping too.
The page->mapping must be the case that works for everybody, not just
the mapping that happened to page it in first.

Here's the scenario:

 - page gets allocated/mapped by process A. Let's call the anon_vma we
   associate the page with 'A' to keep it easy to track.

 - Process A forks, creating process B. The anon_vma in B is 'B', and has
   a chain that looks like 'B' -> 'A'. Everything is fine.

 - Swapping happens. The page (with mapping pointing to 'A') gets swapped
   out (perhaps not to disk - it's enough to assume that it's just not
   mapped any more, and lives entirely in the swap-cache)

 - Process B pages it in, which goes like this:

        do_swap_page ->
          page = lookup_swap_cache(entry);
         ...
          set_pte_at(mm, address, page_table, pte);
          page_add_anon_rmap(page, vma, address);

   And think about what happens here!

   In particular, what happens is that this will now be the "first"
   mapping of that page, so page_add_anon_rmap() used to do

        if (first)
                __page_set_anon_rmap(page, vma, address);

   and notice what anon_vma it will use? It will use the anon_vma for
   process B!

   What happens then? Trivial: process 'A' also pages it in (nothing
   happens, it's not the first mapping), and then process 'B' execve's
   or exits or unmaps, making anon_vma B go away.

   End result: process A has a page that points to anon_vma B, but
   anon_vma B does not exist any more.  This can go on forever.  Forget
   about RCU grace periods, forget about locking, forget anything like
   that.  The bug is simply that page->mapping points to an anon_vma
   that was correct at one point, but was _not_ the one that was shared
   by all users of that possible mapping.

Changing it to always use the deepest anon_vma in the anonvma chain gets
us to the safest model.

This can be improved in certain cases: if we know the page is private to
just this particular mapping (for example, it's a new page, or it is the
only swapcache entry), we could pick the top (most specific) anon_vma.

But that's a future optimization. Make it _work_ reliably first.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "What do you know, I think you fixed it!" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:54:13 -07:00
Linus Torvalds 646d87b481 anon_vma: clone the anon_vma chain in the right order
We want to walk the chain in reverse order when cloning it, so that the
order of the result chain will be the same as the order in the source
chain.  When we add entries to the chain, they go at the head of the
chain, so we want to add the source head last.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "No, it still oopses" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:54:12 -07:00
Linus Torvalds 287d97ac03 vma_adjust: fix the copying of anon_vma chains
When we move the boundaries between two vma's due to things like
mprotect, we need to make sure that the anon_vma of the pages that got
moved from one vma to another gets properly copied around.  And that was
not always the case, in this rather hard-to-follow code sequence.

Clarify the code, and fix it so that it copies the anon_vma from the
right source.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "Yeah, not so much this one either" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:54:11 -07:00
Linus Torvalds d0e9fe1758 Simplify and comment on anon_vma re-use for anon_vma_prepare()
This changes the anon_vma reuse case to require that we only reuse
simple anon_vma's - ie the case when the vma only has a single anon_vma
associated with it.

This means that a reuse of an anon_vma from an adjacent vma will always
guarantee that both vma's are associated not only with the same
anon_vma, they will also have the same anon_vma chain (of just a single
entry in this case).

And since anon_vma re-use was the only case where the same anon_vma
might be associated with different chains of anon_vma's, we now have the
case that every vma that shares the same anon_vma will always also have
the same chain.  That makes it much easier to think about merging vma's
that share the same anon_vma's: you can always just drop the other
anon_vma chain in anon_vma_merge() since you know that they are always
identical.

This also splits up the function to validate the anon_vma re-use, and
adds a lot of commentary about the possible races.

Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Borislav Petkov <bp@alien8.de> [ "That didn't fix it" ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-12 17:53:59 -07:00
Andrew Perepechko 08261673cb quota: Fix possible dq_flags corruption
dq_flags are modified non-atomically in do_set_dqblk via __set_bit calls and
atomically for example in mark_dquot_dirty or clear_dquot_dirty.  Hence a
change done by an atomic operation can be overwritten by a change done by a
non-atomic one. Fix the problem by using atomic bitops even in do_set_dqblk.

Signed-off-by: Andrew Perepechko <andrew.perepechko@sun.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2010-04-12 21:12:36 +02:00
Jan Kara 4c5e6c0e70 quota: Hide warnings about writes to the filesystem before quota was turned on
For a root filesystem write to the filesystem before quota is turned on happens
regularly and there's no way around it because of writes to syslog, /etc/mtab,
and similar. So the warning is rather pointless for ordinary users. It's
still useful during development so we just hide the warning behind
__DQUOT_PARANOIA config option.

Signed-off-by: Jan Kara <jack@suse.cz>
2010-04-12 21:12:19 +02:00
Dmitry Monakhov 774f03fb2c ext3: symlink must be handled via filesystem specific operation
generic setattr implementation is no longer responsible for
quota transfer so synlinks must be handled via ext3_setattr.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2010-04-12 21:11:39 +02:00
Dmitry Monakhov fc7683a3c3 ext2: symlink must be handled via filesystem specific operation
generic setattr implementation is no longer responsible for
quota transfer so synlinks must be handled via ext2_setattr.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2010-04-12 21:11:25 +02:00
David Daney f6be75d03c MIPS: Calculate proper ebase value for 64-bit kernels
The ebase is relative to CKSEG0 not CAC_BASE.  On a 32-bit kernel they
are the same thing, for a 64-bit kernel they are not.

It happens to kind of work on a 64-bit kernel as they both reference
the same physical memory.  However since the CPU uses the CKSEG0 base,
determining if a J instruction will reach always gives the wrong result
unless we use the same number the CPU uses.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1093/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:22 +01:00
Manuel Lauss d8000beef2 MIPS: Alchemy: DB1200: Remove custom wait implementation
While playing with the out-of-tree MAE driver module, the system would
panic after a while in the db1200 custom wait code after wakeup due to
a clobbered k0 register being used as target address of a store op.

Remove the custom wait implementation and revert back to the Alchemy-
recommended implementation already set as default.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/1092/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:22 +01:00
Ralf Baechle 2844e49f5e MIPS: Big Sur: Make defconfig more useful.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:22 +01:00
Anton Altaparmakov 7b3e543ddb MIPS: Fix __vmalloc() etc. on MIPS for non-GPL modules
Commit b3594a089f1c17ff919f8f78505c3f20e1f6f8ce (lmo) rsp.
351336929c (kernel.org) break non-GPL modules
that use __vmalloc() or any of the vmap(), vm_map_ram(), etc functions on
MIPS.

All those functions are EXPORT_SYMBOL() so are meant to be allowed to be
used by non-GPL kernel modules.  These calls all take page protection as
an argument which is normally a constant like PAGE_KERNEL.

This commit causes all protection constants like PAGE_KERNEL to not be
constants and instead to contain the GPL-only symbol _page_cachable_default.

This means that all calls to __vmalloc(), vmap(), etc, cause non-GPL
modules to fail to link with the complaint that they are trying to use the
GPL-only symbol _page_cachable_default...

Change EXPORT_SYMBOL_GPL(_page_cachable_default) to EXPORT_SYMBOL() for
non-GPL modules that call __vmalloc(), vmap(), vm_map_ram() etc.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Cc: Chris Dearman <chris@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/1084/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:21 +01:00
Ralf Baechle 3d45285dd1 MIPS: Sibyte: Fix M3 TLB exception handler workaround.
The M3 workaround needs to cmpare the region and VPN2 fields only.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:21 +01:00
Florian Fainelli 5e3644a95d MIPS: BCM63xx: Fix build failure in board_bcm963xx.c
Since 2083e8327aeeaf818b0e4522a9d2539835c60423, the SPROM is now registered
in the board_prom_init callback, but it references variables and functions
which are declared below.  Move the variables and functions above
board_prom_init.

Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1077/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:20 +01:00
Ralf Baechle 5808184f1b MIPS: uasm: Add OR instruction.
This is needed for the fix of the M3 workaround.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:20 +01:00
Ralf Baechle 8d9df29db2 MIPS: Sibyte: Apply M3 workaround only on affected chip types and versions.
Previously it was unconditionally used on all Sibyte family SOCs.  The
M3 bug has to be handled in the TLB exception handler which is extremly
performance sensitive, so this modification is expected to deliver around
2-3% performance improvment.  This is important as required changes to the
M3 workaround will make it more costly.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:19 +01:00
Maxime Bizon 9538ca636f MIPS: BCM63xx: Initialize gpio_out_low & out_high to current value at boot.
To avoid a glitch during GPIO initialisation read GPIO output register
values left by the firmware.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/903/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:19 +01:00
Florian Fainelli e23a90eb73 MIPS: BCM63xx: Register SSB SPROM fallback in board's first stage callback
Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
To: Maxime Bizon <mbizon@freebox.fr>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1017/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:18 +01:00
Maxime Bizon 4fe67e44a0 MIPS: BCM63xx: Fix typo in cpu-feature-overrides file.
Fix typo: CONFIG_BCMCPU_IS_63xx does not exist;
CONFIG_BCM63XX_CPU_63xx is the valid config option.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
To: linux-mips@linux-mips.org
Cc: Maxime Bizon <mbizon@freebox.fr>
Patchwork: http://patchwork.linux-mips.org/patch/901/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:18 +01:00
Maxime Bizon 524ef29cff MIPS: BCM63xx: Add support for second uart.
The BCm63xx SOC has two uarts.  Some boards use the second one for
bluetooth.  This patch changes platform device registration code to
handle this.  Changes to the UART driver were already merged in
6a2c7eabfd.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
To: linux-mips@linux-mips.org
Cc: Maxime Bizon <mbizon@freebox.fr>
Patchwork: http://patchwork.linux-mips.org/patch/900/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:18 +01:00
Maxime Bizon 97befcf4f0 MIPS: BCM63xx: Fix double gpio registration.
bcm63xx_gpio_init is already called from prom_init to allow board to use
them early, so we can remove the unneeded arch_initcall.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
To: linux-mips@linux-mips.org
Cc: Maxime Bizon <mbizon@freebox.fr>
Patchwork: http://patchwork.linux-mips.org/patch/899/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:17 +01:00
Florian Fainelli f29b7cac19 MIPS: BCM63xx: Add DWVS0 board
The DWVS0 board is a BCM6358-based board with an on-board OHCI controler.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1015/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:17 +01:00
Florian Fainelli 2e6ad9a958 MIPS: BCM63xx: Add the RTA1025W-16 BCM6348-based board to suppported boards.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1014/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:17 +01:00
Florian Fainelli d1b28758c6 MIPS: BCM63xx: Fix BCM6338 and BCM6345 gpio count
The number of GPIOs on BCM6338 is 8, while BCM6345 has only 16 GPIOs
available.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1016/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:16 +01:00
Andrea Gelmini b44c779ae0 MIPS: libgcc.h: Checkpatch cleanup
arch/mips/lib/libgcc.h:21: ERROR: open brace '{' following union go on the same line

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
To: linux-kernel@vger.kernel.org
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: linux-mips@linux-mips.org
Cc: linux-sh@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/1007/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:15 +01:00
Wu Zhangjin f1df323924 MIPS: Loongson-2F: Flush the branch target history in BTB and RAS
As per chapter 15 "Errata: Issue of Out-of-order in loongson"[1] to work
around the Loongson 2F erratum we need to do:

"When switching from user mode to kernel mode, you should flush the
branch target history such as BTB and RAS."

[1] Chinese version: http://www.loongson.cn/uploadfile/file/200808211
[2] English version of chapter 15:
    http://groups.google.com.hk/group/loongson-dev/msg/e0d2e220958f10a6?dmode=source

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Patchwork: http://patchwork.linux-mips.org/patch/1066/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:15 +01:00
David Daney d814c28cec MIPS: Move signal trampolines off of the stack.
This is a follow on to the vdso patch.

Since all processes now have signal trampolines permanently mapped, we
can use those instead of putting the trampoline on the stack and
invalidating the corresponding icache across all CPUs.  We also get rid
of a bunch of ICACHE_REFILLS_WORKAROUND_WAR code.

[Ralf: GDB 7.1 which has the necessary modifications to allow backtracing
over signal frames will supposedly be released tomorrow.  The old signal
frame format obsoleted by this patch exists in two variations, for sane
processors and for those requiring ICACHE_REFILLS_WORKAROUND_WAR.  So
there was never a GDB which did support backtracing over signal frames
on all MIPS systems.  This convinved me this series should be applied and
pushed upstream as soon as possible.]

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/974/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:15 +01:00
David Daney c52d0d30ae MIPS: Preliminary VDSO
This is a preliminary patch to add a vdso to all user processes.  Still
missing are ELF headers and .eh_frame information.  But it is enough to
allow us to move signal trampolines off of the stack.  Note that emulation
of branch delay slots in the FPU emulator still requires the stack.

We allocate a single page (the vdso) and write all possible signal
trampolines into it.  The stack is moved down by one page and the vdso is
mapped into this space.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/975/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:14 +01:00
David Daney 58b9e2239f MIPS: Add SYSCALL to uasm.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/976/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:14 +01:00
Andreas Ferber 847253b948 MIPS: Fix SSB PCIcore IO resource management
The SSB PCIcore code reused the IO resource fixup code from the original
2.4.x Broadcom patch for BCM47xx based devices, which was a quick hack
for doing PCI IO resource configuration back then (the boot loader
doesn't configure PCI devices on this platform).

However, this code is no longer necessary since the kernel now can do
PCI resource management fine all by itself, so remove the old code.

When removing the code, it becomes obvious that the mem_offset setting
in the PCIcore driver was wrong, however this was masked by the fixup
code before, except in a few cases involving yenta_socket. For BCM47xx,
the correct offset is 0, and since this is the only device using PCIcore
in host mode, the offset can simply be removed unconditionally.

Signed-off-by: Andreas Ferber <af@chaos-agency.de>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Markus Wigge <markus@cultcom.de>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1070/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:14 +01:00
Florian Fainelli 86f7d75eb7 MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET
On AR7, we already redefine PHYS_OFFSET to match the system specifities, it
is however not sufficient when unsing dma_{map,unmap}_single, specifically
in the ethernet driver, we must also adjust CAC_ADDR and UNCAC_ADDR for DMA
to work correctly. This patch fixes the following issue, seen in cpmac_open:

ops[#1]:
Cpu 0
$ 0   : 00000000 10008400 a0f5b120 00000000
$ 4   : 94c59000 94270f64 00000020 00000010
$ 8   : 00000010 94103ce0 0000000a 94c03400
$12   : ffffffff 94c03408 94c03410 00000001
$16   : a0f5ba20 00000041 94c592c0 94c59200
$20   : 94c59000 000005ee 00002000 9438c8f0
$24   : 00000010 00000000
$28   : 94fac000 94fadd58 94390000 942724a8
Hi    : 00000000
Lo    : 00000001
epc   : 94272518 cpmac_open+0x208/0x3f8
    Not tainted
ra    : 942724a8 cpmac_open+0x198/0x3f8
Status: 10008403    KERNEL EXL IE
Cause : 3080000c
BadVA : 00000000
PrId  : 00018448 (MIPS 4KEc)
Modules linked in:
Process ifconfig (pid: 278, threadinfo=94fac000, task=94e79590, tls=00000000)
Stack : 7f8da120 2ab05cb0 94c59000 943356f0 00000000 943d0000 94c59000 943356f0
        94c59030 943d0000 943c27c0 94fade10 00000000 94fade20 94c59000 9428e5a4
        00000000 94c59000 00000041 94289768 94c59000 00000041 00001002 00001043
        00000000 9428d810 00000000 94fade10 7f8da4e8 9428e6b8 00000000 7f8da4a8
        7f8da4e8 00008914 00000000 942f7f2c 00000000 00000008 00408000 00008913
        ...
Call Trace:
[<94272518>] cpmac_open+0x208/0x3f8
[<9428e5a4>] dev_open+0x164/0x264
[<9428d810>] dev_change_flags+0xd0/0x1bc
[<942f7f2c>] devinet_ioctl+0x2d8/0x908
[<942771f8>] sock_ioctl+0x29c/0x2fc
[<941a0fb4>] vfs_ioctl+0x2c/0x7c
[<941a16ec>] do_vfs_ioctl+0x5dc/0x630
[<941a1790>] sys_ioctl+0x50/0x88
[<94101e10>] stack_done+0x20/0x3c

Signed-off-by: peter fuerst <post@pfrst.de>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1050/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-04-12 17:26:13 +01:00