Commit Graph

197 Commits

Author SHA1 Message Date
Jan Kara
c01228db4b Revert "scsi, block: fix duplicate bdi name registration crashes"
This reverts commit 0dba1314d4. It causes
leaking of device numbers for SCSI when SCSI registers multiple gendisks
for one request_queue in succession. It can be easily reproduced using
Omar's script [1] on kernel with CONFIG_DEBUG_TEST_DRIVER_REMOVE.
Furthermore the protection provided by this commit is not needed anymore
as the problem it was fixing got also fixed by commit 165a5e22fa
"block: Move bdi_unregister() to del_gendisk()".

[1]: http://marc.info/?l=linux-block&m=148554717109098&w=2

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-08 10:55:17 -07:00
Jan Kara
90f16fddcc block: Make del_gendisk() safer for disks without queues
Commit 165a5e22fa "block: Move bdi_unregister() to del_gendisk()"
added disk->queue dereference to del_gendisk(). Although del_gendisk()
is not supposed to be called without disk->queue valid and
blk_unregister_queue() warns in that case, this change will make it oops
instead. Return to the old more robust behavior of just warning when
del_gendisk() gets called for gendisk with disk->queue being NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-08 10:55:17 -07:00
Jan Kara
165a5e22fa block: Move bdi_unregister() to del_gendisk()
Commit 6cd18e711d "block: destroy bdi before blockdev is
unregistered." moved bdi unregistration (at that time through
bdi_destroy()) from blk_release_queue() to blk_cleanup_queue() because
it needs to happen before blk_unregister_region() call in del_gendisk()
for MD. SCSI though will free up the device number from sd_remove()
called through a maze of callbacks from device_del() in
__scsi_remove_device() before blk_cleanup_queue() and thus similar races
as described in 6cd18e711d can happen for SCSI as well as reported by
Omar [1].

Moving bdi_unregister() to del_gendisk() works for MD and fixes the
problem for SCSI since del_gendisk() gets called from sd_remove() before
freeing the device number.

This also makes device_add_disk() (calling bdi_register_owner()) more
symmetric with del_gendisk().

[1] http://marc.info/?l=linux-block&m=148554717109098&w=2

Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-02 16:08:35 -07:00
Jan Kara
d06e05c026 block: Unhash also block device inode for the whole device
Iteration over partitions in del_gendisk() omits part0. Add
bdev_unhash_inode() call for the whole device. Otherwise if the device
number gets reused, bdev inode will be still associated with the old
(stale) bdi.

Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-21 12:51:54 -07:00
Jan Kara
4b8c861a7c block: Move bdev_unhash_inode() after invalidate_partition()
Move bdev_unhash_inode() after invalidate_partition() as
invalidate_partition() looks up bdev and it cannot find the right bdev
inode after bdev_unhash_inode() is called. Thus invalidate_partition()
would not invalidate page cache of the previously used bdev. Also use
part_devt() when calling bdev_unhash_inode() instead of manually
creating the device number.

Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-21 12:51:54 -07:00
Dan Williams
0dba1314d4 scsi, block: fix duplicate bdi name registration crashes
Warnings of the following form occur because scsi reuses a devt number
while the block layer still has it referenced as the name of the bdi
[1]:

 WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80
 sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192'
 [..]
 Call Trace:
  dump_stack+0x86/0xc3
  __warn+0xcb/0xf0
  warn_slowpath_fmt+0x5f/0x80
  ? kernfs_path_from_node+0x4f/0x60
  sysfs_warn_dup+0x62/0x80
  sysfs_create_dir_ns+0x77/0x90
  kobject_add_internal+0xb2/0x350
  kobject_add+0x75/0xd0
  device_add+0x15a/0x650
  device_create_groups_vargs+0xe0/0xf0
  device_create_vargs+0x1c/0x20
  bdi_register+0x90/0x240
  ? lockdep_init_map+0x57/0x200
  bdi_register_owner+0x36/0x60
  device_add_disk+0x1bb/0x4e0
  ? __pm_runtime_use_autosuspend+0x5c/0x70
  sd_probe_async+0x10d/0x1c0
  async_run_entry_fn+0x39/0x170

This is a brute-force fix to pass the devt release information from
sd_probe() to the locations where we register the bdi,
device_add_disk(), and unregister the bdi, blk_cleanup_queue().

Thanks to Omar for the quick reproducer script [2]. This patch survives
where an unmodified kernel fails in a few seconds.

[1]: https://marc.info/?l=linux-scsi&m=147116857810716&w=4
[2]: http://marc.info/?l=linux-block&m=148554717109098&w=2

Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Reported-by: Omar Sandoval <osandov@osandov.com>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:23:19 -07:00
Jan Kara
dc3b17cc8b block: Use pointer to backing_dev_info from request_queue
We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:20:48 -07:00
Jan Kara
f44f1ab5a2 block: Unhash block device inodes on gendisk destruction
Currently, block device inodes stay around after corresponding gendisk
hash died until memory reclaim finds them and frees them. Since we will
make block device inode pin the bdi, we want to free the block device
inode as soon as the device goes away so that bdi does not stay around
unnecessarily. Furthermore we need to avoid issues when new device with
the same major,minor pair gets created since reusing the bdi structure
would be rather difficult in this case.

Unhashing block device inode on gendisk destruction nicely deals with
these problems. Once last block device inode reference is dropped (which
may be directly in del_gendisk()), the inode gets evicted. Furthermore if
the major,minor pair gets reallocated, we are guaranteed to get new
block device inode even if old block device inode is not yet evicted and
thus we avoid issues with possible reuse of bdi.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:18:41 -07:00
Dan Williams
df08c32ce3 block: fix bdi vs gendisk lifetime mismatch
The name for a bdi of a gendisk is derived from the gendisk's devt.
However, since the gendisk is destroyed before the bdi it leaves a
window where a new gendisk could dynamically reuse the same devt while a
bdi with the same name is still live.  Arrange for the bdi to hold a
reference against its "owner" disk device while it is registered.
Otherwise we can hit sysfs duplicate name collisions like the following:

 WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80
 sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1'

 Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015
  0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec
  ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351
  0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8
 Call Trace:
  [<ffffffff8134caec>] dump_stack+0x63/0x87
  [<ffffffff8108c351>] __warn+0xd1/0xf0
  [<ffffffff8108c3cf>] warn_slowpath_fmt+0x5f/0x80
  [<ffffffff812a0d34>] sysfs_warn_dup+0x64/0x80
  [<ffffffff812a0e1e>] sysfs_create_dir_ns+0x7e/0x90
  [<ffffffff8134faaa>] kobject_add_internal+0xaa/0x320
  [<ffffffff81358d4e>] ? vsnprintf+0x34e/0x4d0
  [<ffffffff8134ff55>] kobject_add+0x75/0xd0
  [<ffffffff816e66b2>] ? mutex_lock+0x12/0x2f
  [<ffffffff8148b0a5>] device_add+0x125/0x610
  [<ffffffff8148b788>] device_create_groups_vargs+0xd8/0x100
  [<ffffffff8148b7cc>] device_create_vargs+0x1c/0x20
  [<ffffffff811b775c>] bdi_register+0x8c/0x180
  [<ffffffff811b7877>] bdi_register_dev+0x27/0x30
  [<ffffffff813317f5>] add_disk+0x175/0x4a0

Cc: <stable@vger.kernel.org>
Reported-by: Yi Zhang <yizhan@redhat.com>
Tested-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Fixed up missing 0 return in bdi_register_owner().

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04 14:19:16 -06:00
Vegard Nossum
77da160530 block: fix use-after-free in seq file
I got a KASAN report of use-after-free:

    ==================================================================
    BUG: KASAN: use-after-free in klist_iter_exit+0x61/0x70 at addr ffff8800b6581508
    Read of size 8 by task trinity-c1/315
    =============================================================================
    BUG kmalloc-32 (Not tainted): kasan: bad access detected
    -----------------------------------------------------------------------------

    Disabling lock debugging due to kernel taint
    INFO: Allocated in disk_seqf_start+0x66/0x110 age=144 cpu=1 pid=315
            ___slab_alloc+0x4f1/0x520
            __slab_alloc.isra.58+0x56/0x80
            kmem_cache_alloc_trace+0x260/0x2a0
            disk_seqf_start+0x66/0x110
            traverse+0x176/0x860
            seq_read+0x7e3/0x11a0
            proc_reg_read+0xbc/0x180
            do_loop_readv_writev+0x134/0x210
            do_readv_writev+0x565/0x660
            vfs_readv+0x67/0xa0
            do_preadv+0x126/0x170
            SyS_preadv+0xc/0x10
            do_syscall_64+0x1a1/0x460
            return_from_SYSCALL_64+0x0/0x6a
    INFO: Freed in disk_seqf_stop+0x42/0x50 age=160 cpu=1 pid=315
            __slab_free+0x17a/0x2c0
            kfree+0x20a/0x220
            disk_seqf_stop+0x42/0x50
            traverse+0x3b5/0x860
            seq_read+0x7e3/0x11a0
            proc_reg_read+0xbc/0x180
            do_loop_readv_writev+0x134/0x210
            do_readv_writev+0x565/0x660
            vfs_readv+0x67/0xa0
            do_preadv+0x126/0x170
            SyS_preadv+0xc/0x10
            do_syscall_64+0x1a1/0x460
            return_from_SYSCALL_64+0x0/0x6a

    CPU: 1 PID: 315 Comm: trinity-c1 Tainted: G    B           4.7.0+ #62
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
     ffffea0002d96000 ffff880119b9f918 ffffffff81d6ce81 ffff88011a804480
     ffff8800b6581500 ffff880119b9f948 ffffffff8146c7bd ffff88011a804480
     ffffea0002d96000 ffff8800b6581500 fffffffffffffff4 ffff880119b9f970
    Call Trace:
     [<ffffffff81d6ce81>] dump_stack+0x65/0x84
     [<ffffffff8146c7bd>] print_trailer+0x10d/0x1a0
     [<ffffffff814704ff>] object_err+0x2f/0x40
     [<ffffffff814754d1>] kasan_report_error+0x221/0x520
     [<ffffffff8147590e>] __asan_report_load8_noabort+0x3e/0x40
     [<ffffffff83888161>] klist_iter_exit+0x61/0x70
     [<ffffffff82404389>] class_dev_iter_exit+0x9/0x10
     [<ffffffff81d2e8ea>] disk_seqf_stop+0x3a/0x50
     [<ffffffff8151f812>] seq_read+0x4b2/0x11a0
     [<ffffffff815f8fdc>] proc_reg_read+0xbc/0x180
     [<ffffffff814b24e4>] do_loop_readv_writev+0x134/0x210
     [<ffffffff814b4c45>] do_readv_writev+0x565/0x660
     [<ffffffff814b8a17>] vfs_readv+0x67/0xa0
     [<ffffffff814b8de6>] do_preadv+0x126/0x170
     [<ffffffff814b92ec>] SyS_preadv+0xc/0x10

This problem can occur in the following situation:

open()
 - pread()
    - .seq_start()
       - iter = kmalloc() // succeeds
       - seqf->private = iter
    - .seq_stop()
       - kfree(seqf->private)
 - pread()
    - .seq_start()
       - iter = kmalloc() // fails
    - .seq_stop()
       - class_dev_iter_exit(seqf->private) // boom! old pointer

As the comment in disk_seqf_stop() says, stop is called even if start
failed, so we need to reinitialise the private pointer to NULL when seq
iteration stops.

An alternative would be to set the private pointer to NULL when the
kmalloc() in disk_seqf_start() fails.

Cc: stable@vger.kernel.org
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04 14:19:16 -06:00
Linus Torvalds
3fc9d69093 Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
 "This branch also contains core changes.  I've come to the conclusion
  that from 4.9 and forward, I'll be doing just a single branch.  We
  often have dependencies between core and drivers, and it's hard to
  always split them up appropriately without pulling core into drivers
  when that happens.

  That said, this contains:

   - separate secure erase type for the core block layer, from
     Christoph.

   - set of discard fixes, from Christoph.

   - bio shrinking fixes from Christoph, as a followup up to the
     op/flags change in the core branch.

   - map and append request fixes from Christoph.

   - NVMeF (NVMe over Fabrics) code from Christoph.  This is pretty
     exciting!

   - nvme-loop fixes from Arnd.

   - removal of ->driverfs_dev from Dan, after providing a
     device_add_disk() helper.

   - bcache fixes from Bhaktipriya and Yijing.

   - cdrom subchannel read fix from Vchannaiah.

   - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier.

   - set of drbd updates and fixes from Fabian, Lars, and Philipp.

   - mg_disk error path fix from Bart.

   - user notification for failed device add for loop, from Minfei.

   - NVMe in general:
        + NVMe delay quirk from Guilherme.
        + SR-IOV support and command retry limits from Keith.
        + fix for memory-less NUMA node from Masayoshi.
        + use UINT_MAX for discard sectors, from Minfei.
        + cancel IO fixes from Ming.
        + don't allocate unused major, from Neil.
        + error code fixup from Dan.
        + use constants for PSDT/FUSE from James.
        + variable init fix from Jay.
        + fabrics fixes from Ming, Sagi, and Wei.
        + various fixes"

* 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits)
  nvme/pci: Provide SR-IOV support
  nvme: initialize variable before logical OR'ing it
  block: unexport various bio mapping helpers
  scsi/osd: open code blk_make_request
  target: stop using blk_make_request
  block: simplify and export blk_rq_append_bio
  block: ensure bios return from blk_get_request are properly initialized
  virtio_blk: use blk_rq_map_kern
  memstick: don't allow REQ_TYPE_BLOCK_PC requests
  block: shrink bio size again
  block: simplify and cleanup bvec pool handling
  block: get rid of bio_rw and READA
  block: don't ignore -EOPNOTSUPP blkdev_issue_write_same
  block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
  NVMe: don't allocate unused nvme_major
  nvme: avoid crashes when node 0 is memoryless node.
  nvme: Limit command retries
  loop: Make user notify for adding loop device failed
  nvme-loop: fix nvme-loop Kconfig dependencies
  nvmet: fix return value check in nvmet_subsys_alloc()
  ...
2016-07-26 15:37:51 -07:00
Thomas Gleixner
53bf837b78 timers: Remove set_timer_slack() leftovers
We now have implicit batching in the timer wheel. The slack API is no longer
used, so remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094342.189813118@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-07 10:35:09 +02:00
Dan Williams
52c44d93c2 block: remove ->driverfs_dev
Now that all drivers that specify a ->driverfs_dev have been converted
to device_add_disk(), the pointer can be removed from struct gendisk.

Cc: Jens Axboe <axboe@fb.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-27 12:26:08 -07:00
Dan Williams
e63a46bef0 block: introduce device_add_disk()
In preparation for removing the ->driverfs_dev member of a gendisk, add
an api that takes the parent device as a parameter to add_disk().  For
now this maintains the status quo of WARN()ing on failure, but not
return a error code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-15 19:53:06 -07:00
Linus Torvalds
7c24d9f3b2 Merge branch 'for-4.5/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "We don't have a lot of core changes this time around, it's mostly in
  drivers, which will come in a subsequent pull.

  The cores changes include:

   - blk-mq
        - Prep patch from Christoph, changing blk_mq_alloc_request() to
          take flags instead of just using gfp_t for sleep/nosleep.
        - Doc patch from me, clarifying the difference between legacy
          and blk-mq for timer usage.
        - Fixes from Raghavendra for memory-less numa nodes, and a reuse
          of CPU masks.

   - Cleanup from Geliang Tang, using offset_in_page() instead of open
     coding it.

   - From Ilya, rename request_queue slab to it reflects what it holds,
     and a fix for proper use of bdgrab/put.

   - A real fix for the split across stripe boundaries from Keith.  We
     yanked a broken version of this from 4.4-rc final, this one works.

   - From Mike Krinkin, emit a trace message when we split.

   - From Wei Tang, two small cleanups, not explicitly clearing memory
     that is already cleared"

* 'for-4.5/core' of git://git.kernel.dk/linux-block:
  block: use bd{grab,put}() instead of open-coding
  block: split bios to max possible length
  block: add call to split trace point
  blk-mq: Avoid memoryless numa node encoded in hctx numa_node
  blk-mq: Reuse hardware context cpumask for tags
  blk-mq: add a flags parameter to blk_mq_alloc_request
  Revert "blk-flush: Queue through IO scheduler when flush not required"
  block: clarify blk_add_timer() use case for blk-mq
  bio: use offset_in_page macro
  block: do not initialise statics to 0 or NULL
  block: do not initialise globals to 0 or NULL
  block: rename request_queue slab cache
2016-01-19 15:03:34 -08:00
Dan Williams
55f5560d8c block: kill disk_{check|set|clear|alloc}_badblocks
These actions are completely managed by a block driver or can use the
badblocks api directly.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 22:42:31 -08:00
Dan Williams
20a308f09e block: clarify badblocks lifetime
The badblocks list attached to a gendisk is allocated by the driver
which equates to the driver owning the lifetime of the object.  Do not
automatically free it in del_gendisk(). This is in preparation for
expanding the use of badblocks in libnvdimm drivers and introducing
devm_init_badblocks().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:39:04 -08:00
Dan Williams
d3b407fb3f badblocks: rename badblocks_free to badblocks_exit
For symmetry with badblocks_init() make it clear that this path only
destroys incremental allocations of a badblocks instance, and does not
free the badblocks instance itself.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:39:04 -08:00
Vishal Verma
99e6608c9e block: Add badblock management for gendisks
NVDIMM devices, which can behave more like DRAM rather than block
devices, may develop bad cache lines, or 'poison'. A block device
exposed by the pmem driver can then consume poison via a read (or
write), and cause a machine check. On platforms without machine
check recovery features, this would mean a crash.

The block device maintaining a runtime list of all known sectors that
have poison can directly avoid this, and also provide a path forward
to enable proper handling/recovery for DAX faults on such a device.

Use the new badblock management interfaces to add a badblocks list to
gendisks.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:36:51 -08:00
Dan Williams
ac34f15e0c block: fix del_gendisk() vs blkdev_ioctl crash
When tearing down a block device early in its lifetime, userspace may
still be performing discovery actions like blkdev_ioctl() to re-read
partitions.

The nvdimm_revalidate_disk() implementation depends on
disk->driverfs_dev to be valid at entry.  However, it is set to NULL in
del_gendisk() and fatally this is happening *before* the disk device is
deleted from userspace view.

There's no reason for del_gendisk() to clear ->driverfs_dev.  That
device is the parent of the disk.  It is guaranteed to not be freed
until the disk, as a child, drops its ->parent reference.

We could also fix this issue locally in nvdimm_revalidate_disk() by
using disk_to_dev(disk)->parent, but lets fix it globally since
->driverfs_dev follows the lifetime of the parent.  Longer term we
should probably just add a @parent parameter to add_disk(), and stop
carrying this pointer in the gendisk.

 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<ffffffffa00340a8>] nvdimm_revalidate_disk+0x18/0x90 [libnvdimm]
 CPU: 2 PID: 538 Comm: systemd-udevd Tainted: G           O    4.4.0-rc5 #2257
 [..]
 Call Trace:
  [<ffffffff8143e5c7>] rescan_partitions+0x87/0x2c0
  [<ffffffff810f37f9>] ? __lock_is_held+0x49/0x70
  [<ffffffff81438c62>] __blkdev_reread_part+0x72/0xb0
  [<ffffffff81438cc5>] blkdev_reread_part+0x25/0x40
  [<ffffffff8143982d>] blkdev_ioctl+0x4fd/0x9c0
  [<ffffffff811246c9>] ? current_kernel_time64+0x69/0xd0
  [<ffffffff812916dd>] block_ioctl+0x3d/0x50
  [<ffffffff81264c38>] do_vfs_ioctl+0x308/0x560
  [<ffffffff8115dbd1>] ? __audit_syscall_entry+0xb1/0x100
  [<ffffffff810031d6>] ? do_audit_syscall_entry+0x66/0x70
  [<ffffffff81264f09>] SyS_ioctl+0x79/0x90
  [<ffffffff81902672>] entry_SYSCALL_64_fastpath+0x12/0x76

Reported-by: Robert Hu <robert.hu@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 06:35:12 -08:00
Wei Tang
1fe8f34841 block: do not initialise statics to 0 or NULL
This patch fixes the checkpatch.pl error to genhd.c:

ERROR: do not initialise statics to 0 or NULL

Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:25 -07:00
Martin K. Petersen
25520d55cd block: Inline blk_integrity in struct gendisk
Up until now the_integrity profile has been dynamically allocated and
attached to struct gendisk after the disk has been made active.

This causes problems because NVMe devices need to register the profile
prior to the partition table being read due to a mandatory metadata
buffer requirement. In addition, DM goes through hoops to deal with
preallocating, but not initializing integrity profiles.

Since the integrity profile is small (4 bytes + a pointer), Christoph
suggested moving it to struct gendisk proper. This requires several
changes:

 - Moving the blk_integrity definition to genhd.h.

 - Inlining blk_integrity in struct gendisk.

 - Removing the dynamic allocation code.

 - Adding helper functions which allow gendisk to set up and tear down
   the integrity sysfs dir when a disk is added/deleted.

 - Adding a blk_integrity_revalidate() callback for updating the stable
   pages bdi setting.

 - The calls that depend on whether a device has an integrity profile or
   not now key off of the bi->profile pointer.

 - Simplifying the integrity support routines in DM (Mike Snitzer).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:42 -06:00
Ming Lei
6c71013ecb block: partition: convert percpu ref
Percpu refcount is the perfect match for partition's case,
and the conversion is quite straight.

With the convertion, one pair of atomic inc/dec can be saved
for accounting block I/O, which is run in hot path of block I/O.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17 08:41:53 -06:00
Ming Lei
b54e5ed8f2 block: partition: introduce hd_free_part()
So the helper can be used in both generic partition
case and part0 case.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17 08:41:53 -06:00
Linus Torvalds
e4bc13adfd Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block
Pull cgroup writeback support from Jens Axboe:
 "This is the big pull request for adding cgroup writeback support.

  This code has been in development for a long time, and it has been
  simmering in for-next for a good chunk of this cycle too.  This is one
  of those problems that has been talked about for at least half a
  decade, finally there's a solution and code to go with it.

  Also see last weeks writeup on LWN:

        http://lwn.net/Articles/648292/"

* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
  writeback, blkio: add documentation for cgroup writeback support
  vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
  writeback: do foreign inode detection iff cgroup writeback is enabled
  v9fs: fix error handling in v9fs_session_init()
  bdi: fix wrong error return value in cgwb_create()
  buffer: remove unusued 'ret' variable
  writeback: disassociate inodes from dying bdi_writebacks
  writeback: implement foreign cgroup inode bdi_writeback switching
  writeback: add lockdep annotation to inode_to_wb()
  writeback: use unlocked_inode_to_wb transaction in inode_congested()
  writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
  writeback: implement [locked_]inode_to_wb_and_lock_list()
  writeback: implement foreign cgroup inode detection
  writeback: make writeback_control track the inode being written back
  writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
  mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
  writeback: implement memcg writeback domain based throttling
  writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
  writeback: implement memcg wb_domain
  writeback: update wb_over_bg_thresh() to use wb_domain aware operations
  ...
2015-06-25 16:00:17 -07:00
Dan Williams
4d66e5e9b6 block: fix ext_dev_lock lockdep report
=================================
 [ INFO: inconsistent lock state ]
 4.1.0-rc7+ #217 Tainted: G           O
 ---------------------------------
 inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
 swapper/6/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
  (ext_devt_lock){+.?...}, at: [<ffffffff8143a60c>] blk_free_devt+0x3c/0x70
 {SOFTIRQ-ON-W} state was registered at:
   [<ffffffff810bf6b1>] __lock_acquire+0x461/0x1e70
   [<ffffffff810c1947>] lock_acquire+0xb7/0x290
   [<ffffffff818ac3a8>] _raw_spin_lock+0x38/0x50
   [<ffffffff8143a07d>] blk_alloc_devt+0x6d/0xd0  <-- take the lock in process context
[..]
  [<ffffffff810bf64e>] __lock_acquire+0x3fe/0x1e70
  [<ffffffff810c00ad>] ? __lock_acquire+0xe5d/0x1e70
  [<ffffffff810c1947>] lock_acquire+0xb7/0x290
  [<ffffffff8143a60c>] ? blk_free_devt+0x3c/0x70
  [<ffffffff818ac3a8>] _raw_spin_lock+0x38/0x50
  [<ffffffff8143a60c>] ? blk_free_devt+0x3c/0x70
  [<ffffffff8143a60c>] blk_free_devt+0x3c/0x70    <-- take the lock in softirq
  [<ffffffff8143bfec>] part_release+0x1c/0x50
  [<ffffffff8158edf6>] device_release+0x36/0xb0
  [<ffffffff8145ac2b>] kobject_cleanup+0x7b/0x1a0
  [<ffffffff8145aad0>] kobject_put+0x30/0x70
  [<ffffffff8158f147>] put_device+0x17/0x20
  [<ffffffff8143c29c>] delete_partition_rcu_cb+0x16c/0x180
  [<ffffffff8143c130>] ? read_dev_sector+0xa0/0xa0
  [<ffffffff810e0e0f>] rcu_process_callbacks+0x2ff/0xa90
  [<ffffffff810e0dcf>] ? rcu_process_callbacks+0x2bf/0xa90
  [<ffffffff81067e2e>] __do_softirq+0xde/0x600

Neil sees this in his tests and it also triggers on pmem driver unbind
for the libnvdimm tests.  This fix is on top of an initial fix by Keith
for incorrect usage of mutex_lock() in this path: 2da78092dd "block:
Fix dev_t minor allocation lifetime".  Both this and 2da78092dd are
candidates for -stable.

Fixes: 2da78092dd ("block: Fix dev_t minor allocation lifetime")
Cc: <stable@vger.kernel.org>
Cc: Keith Busch <keith.busch@intel.com>
Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-11 09:01:40 -06:00
Tejun Heo
66114cad64 writeback: separate out include/linux/backing-dev-defs.h
With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it.  c files
which need access to more backing-dev details now include
backing-dev.h directly.  This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
NeilBrown
aad653a0bc block: discard bdi_unregister() in favour of bdi_destroy()
bdi_unregister() now contains very little functionality.

It contains a "WARN_ON" if bdi->dev is NULL.  This warning is of no
real consequence as bdi->dev isn't needed by anything else in the function,
and it triggers if
   blk_cleanup_queue() -> bdi_destroy()
is called before bdi_unregister, which happens since
  Commit: 6cd18e711d ("block: destroy bdi before blockdev is unregistered.")

So this isn't wanted.

It also calls bdi_set_min_ratio().  This needs to be called after
writes through the bdi have all been flushed, and before the bdi is destroyed.
Calling it early is better than calling it late as it frees up a global
resource.

Calling it immediately after bdi_wb_shutdown() in bdi_destroy()
perfectly fits these requirements.

So bdi_unregister() can be discarded with the important content moved to
bdi_destroy(), as can the
  writeback_bdi_unregister
event which is already not used.

Reported-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org (v4.0)
Fixes: c4db59d31e ("fs: don't reassign dirty inodes to default_backing_dev_info")
Fixes: 6cd18e711d ("block: destroy bdi before blockdev is unregistered.")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-28 10:12:42 -06:00
Jens Axboe
5fabcb4c33 genhd: check for int overflow in disk_expand_part_tbl()
We can get here from blkdev_ioctl() -> blkpg_ioctl() -> add_partition()
with a user passed in partno value. If we pass in 0x7fffffff, the
new target in disk_expand_part_tbl() overflows the 'int' and we
access beyond the end of ptbl->part[] and even write to it when we
do the rcu_assign_pointer() to assign the new partition.

Reported-by: David Ramos <daramos@stanford.edu>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-19 13:09:07 -07:00
Linus Torvalds
28596c9722 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull "trivial tree" updates from Jiri Kosina:
 "Usual pile from trivial tree everyone is so eagerly waiting for"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Remove MN10300_PROC_MN2WS0038
  mei: fix comments
  treewide: Fix typos in Kconfig
  kprobes: update jprobe_example.c for do_fork() change
  Documentation: change "&" to "and" in Documentation/applying-patches.txt
  Documentation: remove obsolete pcmcia-cs from Changes
  Documentation: update links in Changes
  Documentation: Docbook: Fix generated DocBook/kernel-api.xml
  score: Remove GENERIC_HAS_IOMAP
  gpio: fix 'CONFIG_GPIO_IRQCHIP' comments
  tty: doc: Fix grammar in serial/tty
  dma-debug: modify check_for_stack output
  treewide: fix errors in printk
  genirq: fix reference in devm_request_threaded_irq comment
  treewide: fix synchronize_rcu() in comments
  checkstack.pl: port to AArch64
  doc: queue-sysfs: minor fixes
  init/do_mounts: better syntax description
  MIPS: fix comment spelling
  powerpc/simpleboot: fix comment
  ...
2014-10-07 21:16:26 -04:00
Jens Axboe
46f341ffcf genhd: fix leftover might_sleep() in blk_free_devt()
Commit 2da78092 changed the locking from a mutex to a spinlock,
so we now longer sleep in this context. But there was a leftover
might_sleep() in there, which now triggers since we do the final
free from an RCU callback. Get rid of it.

Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-22 14:45:45 -06:00
Masanari Iida
da3dae54e4 Documentation: Docbook: Fix generated DocBook/kernel-api.xml
This patch fix spelling typo found in DocBook/kernel-api.xml.
It is because the file is generated from the source comments,
I have to fix the comments in source codes.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-09 10:34:56 +02:00
Keith Busch
2da78092dd block: Fix dev_t minor allocation lifetime
Releases the dev_t minor when all references are closed to prevent
another device from acquiring the same major/minor.

Since the partition's release may be invoked from call_rcu's soft-irq
context, the ext_dev_idr's mutex had to be replaced with a spinlock so
as not so sleep.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-03 15:01:02 -06:00
Joe Perches
c1b511eb21 block: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...)
Use the helper function instead of __GFP_ZERO.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-09-11 13:22:03 -06:00
Kees Cook
ffc8b30866 block: do not pass disk names as format strings
Disk names may contain arbitrary strings, so they must not be
interpreted as format strings.  It seems that only md allows arbitrary
strings to be used for disk names, but this could allow for a local
memory corruption from uid 0 into ring 0.

CVE-2013-2851

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:25 -07:00
Viresh Kumar
695588f945 block: queue work on power efficient wq
Block layer uses workqueues for multiple purposes. There is no real dependency
of scheduling these on the cpu which scheduled them.

On a idle system, it is observed that and idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which the
scheduler believes to be the most appropriate one.

This patch replaces normal workqueues with power efficient versions.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-05-14 10:50:07 -07:00
Greg Kroah-Hartman
4e4098a3e0 driver core: handle user namespaces properly with the uid/gid devtmpfs change
Now that devtmpfs is caring about uid/gid, we need to use the correct
internal types so users who have USER_NS enabled will have things work
properly for them.

Thanks to Eric for pointing this out, and the patch review.

Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-11 11:43:29 -07:00
Kay Sievers
3c2670e651 driver core: add uid and gid to devtmpfs
Some drivers want to tell userspace what uid and gid should be used for
their device nodes, so allow that information to percolate through the
driver core to userspace in order to make this happen.  This means that
some systems (i.e.  Android and friends) will not need to even run a
udev-like daemon for their device node manager and can just rely in
devtmpfs fully, reducing their footprint even more.

Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-08 08:21:48 -07:00
Tejun Heo
bab998d62f block: convert to idr_alloc()
Convert to the much saner new idr interface.  Both bsg and genhd
protect idr w/ mutex making preloading unnecessary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:15 -08:00
Tejun Heo
ce23bba842 block: fix synchronization and limit check in blk_alloc_devt()
idr allocation in blk_alloc_devt() wasn't synchronized against lookup
and removal, and its limit check was off by one - 1 << MINORBITS is
the number of minors allowed, not the maximum allowed minor.

Add locking and rename MAX_EXT_DEVT to NR_EXT_DEVT and fix limit
checking.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:14 -08:00
Tomas Henzl
7b74e91278 block: fix ext_devt_idr handling
While adding and removing a lot of disks disks and partitions this
sometimes shows up:

  WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted)
  Hardware name:
  sysfs: cannot create duplicate filename '/dev/block/259:751'
  Modules linked in: raid1 autofs4 bnx2fc cnic uio fcoe libfcoe libfc 8021q scsi_transport_fc scsi_tgt garp stp llc sunrpc cpufreq_ondemand powernow_k8 freq_table mperf ipv6 dm_mirror dm_region_hash dm_log power_meter microcode dcdbas serio_raw amd64_edac_mod edac_core edac_mce_amd i2c_piix4 i2c_core k10temp bnx2 sg ixgbe dca mdio ext4 mbcache jbd2 dm_round_robin sr_mod cdrom sd_mod crc_t10dif ata_generic pata_acpi pata_atiixp ahci mptsas mptscsih mptbase scsi_transport_sas dm_multipath dm_mod [last unloaded: scsi_wait_scan]
  Pid: 44103, comm: async/16 Not tainted 2.6.32-195.el6.x86_64 #1
  Call Trace:
    warn_slowpath_common+0x87/0xc0
    warn_slowpath_fmt+0x46/0x50
    sysfs_add_one+0xc9/0x130
    sysfs_do_create_link+0x12b/0x170
    sysfs_create_link+0x13/0x20
    device_add+0x317/0x650
    idr_get_new+0x13/0x50
    add_partition+0x21c/0x390
    rescan_partitions+0x32b/0x470
    sd_open+0x81/0x1f0 [sd_mod]
    __blkdev_get+0x1b6/0x3c0
    blkdev_get+0x10/0x20
    register_disk+0x155/0x170
    add_disk+0xa6/0x160
    sd_probe_async+0x13b/0x210 [sd_mod]
    add_wait_queue+0x46/0x60
    async_thread+0x102/0x250
    default_wake_function+0x0/0x20
    async_thread+0x0/0x250
    kthread+0x96/0xa0
    child_rip+0xa/0x20
    kthread+0x0/0xa0
    child_rip+0x0/0x20

This most likely happens because dev_t is freed while the number is
still used and idr_get_new() is not protected on every use.  The fix
adds a mutex where it wasn't before and moves the dev_t free function so
it is called after device del.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:12 -08:00
Ming Lei
25e823c8c3 block/genhd.c: apply pm_runtime_set_memalloc_noio on block devices
Apply the introduced pm_runtime_set_memalloc_noio on block device so
that PM core will teach mm to not allocate memory with GFP_IOFS when
calling the runtime_resume and runtime_suspend callback for block
devices and its ancestors.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Jiri Kosina <jiri.kosina@suse.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Decotigny <david.decotigny@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:16 -08:00
Derek Basehore
12c2bdb232 block: prevent race/cleanup
Remove a race condition which causes a warning in disk_clear_events.  This
is a race between disk_clear_events() and disk_flush_events().
ev->clearing will be altered by disk_flush_events() even though we are
blocking event checking through disk_flush_events().  If this happens
after ev->clearing was cleared for disk_clear_events(), this can cause the
WARN_ON_ONCE() in that function to be triggered.

This change also has disk_clear_events() not go through a workqueue.
Since we have to wait for the work to complete, we should just call the
function directly.  Also, since this work cannot be put on a freezable
workqueue, it will have to contend with increased demand, so calling the
function directly avoids this.

[akpm@linux-foundation.org: fix spello in comment]
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-12-19 20:36:10 +01:00
Derek Basehore
aea24a8bbc block: remove deadlock in disk_clear_events
In disk_clear_events, do not put work on system_nrt_freezable_wq.
Instead, put it on system_nrt_wq.

There is a race between probing a usb and suspending the device.  Since
probing a usb calls disk_clear_events, which puts work on a frozen
workqueue, probing cannot finish after the workqueue is frozen.  However,
suspending cannot finish until the usb probe is finished, so we get a
deadlock, causing the system to reboot.

The way to reproduce this bug is to wake up from suspend with a usb
storage device plugged in, or plugging in a usb storage device right
before suspend.  The window of time is on the order of time it takes to
probe the usb device.  As long as the workqueues are frozen before the
call to add_disk within sd_probe_async finishes, there will be a deadlock
(which calls blkdev_get, sd_open, check_disk_change, then
disk_clear_events).  This is not difficult to reproduce after figuring out
the timings.

[akpm@linux-foundation.org: fix up comment]
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-12-19 20:36:05 +01:00
Linus Torvalds
9228ff9038 Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block
Pull block driver update from Jens Axboe:
 "Now that the core bits are in, here are the driver bits for 3.8.  The
  branch contains:

   - A huge pile of drbd bits that were dumped from the 3.7 merge
     window.  Following that, it was both made perfectly clear that
     there is going to be no more over-the-wall pulls and how the
     situation on individual pulls can be improved.

   - A few cleanups from Akinobu Mita for drbd and cciss.

   - Queue improvement for loop from Lukas.  This grew into adding a
     generic interface for waiting/checking an even with a specific
     lock, allowing this to be pulled out of md and now loop and drbd is
     also using it.

   - A few fixes for xen back/front block driver from Roger Pau Monne.

   - Partition improvements from Stephen Warren, allowing partiion UUID
     to be used as an identifier."

* 'for-3.8/drivers' of git://git.kernel.dk/linux-block: (609 commits)
  drbd: update Kconfig to match current dependencies
  drbd: Fix drbdsetup wait-connect, wait-sync etc... commands
  drbd: close race between drbd_set_role and drbd_connect
  drbd: respect no-md-barriers setting also when changed online via disk-options
  drbd: Remove obsolete check
  drbd: fixup after wait_even_lock_irq() addition to generic code
  loop: Limit the number of requests in the bio list
  wait: add wait_event_lock_irq() interface
  xen-blkfront: free allocated page
  xen-blkback: move free persistent grants code
  block: partition: msdos: provide UUIDs for partitions
  init: reduce PARTUUID min length to 1 from 36
  block: store partition_meta_info.uuid as a string
  cciss: use check_signature()
  cciss: cleanup bitops usage
  drbd: use copy_highpage
  drbd: if the replication link breaks during handshake, keep retrying
  drbd: check return of kmalloc in receive_uuids
  drbd: Broadcast sync progress no more often than once per second
  drbd: don't try to clear bits once the disk has failed
  ...
2012-12-17 13:39:11 -08:00
Stephen Warren
1ad7e89940 block: store partition_meta_info.uuid as a string
This will allow other types of UUID to be stored here, aside from true
UUIDs.  This also simplifies code that uses this field, since it's usually
constructed from a, used as a, or compared to other, strings.

Note: A simplistic approach here would be to set uuid_str[36]=0 whenever a
/PARTNROFF option was found to be present.  However, this modifies the
input string, and causes subsequent calls to devt_from_partuuid() not to
see the /PARTNROFF option, which causes different results.  In order to
avoid misleading future maintainers, this parameter is marked const.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-23 14:28:53 +01:00
Ezequiel Garcia
c304a51bf4 block: use NUMA_NO_NODE instead of -1
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>

Modified by me to cover blk_init_queue() as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-10 10:41:13 +01:00
Linus Torvalds
033d9959ed Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "This is workqueue updates for v3.7-rc1.  A lot of activities this
  round including considerable API and behavior cleanups.

   * delayed_work combines a timer and a work item.  The handling of the
     timer part has always been a bit clunky leading to confusing
     cancelation API with weird corner-case behaviors.  delayed_work is
     updated to use new IRQ safe timer and cancelation now works as
     expected.

   * Another deficiency of delayed_work was lack of the counterpart of
     mod_timer() which led to cancel+queue combinations or open-coded
     timer+work usages.  mod_delayed_work[_on]() are added.

     These two delayed_work changes make delayed_work provide interface
     and behave like timer which is executed with process context.

   * A work item could be executed concurrently on multiple CPUs, which
     is rather unintuitive and made flush_work() behavior confusing and
     half-broken under certain circumstances.  This problem doesn't
     exist for non-reentrant workqueues.  While non-reentrancy check
     isn't free, the overhead is incurred only when a work item bounces
     across different CPUs and even in simulated pathological scenario
     the overhead isn't too high.

     All workqueues are made non-reentrant.  This removes the
     distinction between flush_[delayed_]work() and
     flush_[delayed_]_work_sync().  The former is now as strong as the
     latter and the specified work item is guaranteed to have finished
     execution of any previous queueing on return.

   * In addition to the various bug fixes, Lai redid and simplified CPU
     hotplug handling significantly.

   * Joonsoo introduced system_highpri_wq and used it during CPU
     hotplug.

  There are two merge commits - one to pull in IRQ safe timer from
  tip/timers/core and the other to pull in CPU hotplug fixes from
  wq/for-3.6-fixes as Lai's hotplug restructuring depended on them."

Fixed a number of trivial conflicts, but the more interesting conflicts
were silent ones where the deprecated interfaces had been used by new
code in the merge window, and thus didn't cause any real data conflicts.

Tejun pointed out a few of them, I fixed a couple more.

* 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits)
  workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending()
  workqueue: use cwq_set_max_active() helper for workqueue_set_max_active()
  workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()
  workqueue: remove @delayed from cwq_dec_nr_in_flight()
  workqueue: fix possible stall on try_to_grab_pending() of a delayed work item
  workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback()
  workqueue: use __cpuinit instead of __devinit for cpu callbacks
  workqueue: rename manager_mutex to assoc_mutex
  workqueue: WORKER_REBIND is no longer necessary for idle rebinding
  workqueue: WORKER_REBIND is no longer necessary for busy rebinding
  workqueue: reimplement idle worker rebinding
  workqueue: deprecate __cancel_delayed_work()
  workqueue: reimplement cancel_delayed_work() using try_to_grab_pending()
  workqueue: use mod_delayed_work() instead of __cancel + queue
  workqueue: use irqsafe timer for delayed_work
  workqueue: clean up delayed_work initializers and add missing one
  workqueue: make deferrable delayed_work initializer names consistent
  workqueue: cosmetic whitespace updates for macro definitions
  workqueue: deprecate system_nrt[_freezable]_wq
  workqueue: deprecate flush[_delayed]_work_sync()
  ...
2012-10-02 09:54:49 -07:00
Tejun Heo
3b07e9ca26 workqueue: deprecate system_nrt[_freezable]_wq
system_nrt[_freezable]_wq are now spurious.  Mark them deprecated and
convert all users to system[_freezable]_wq.

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant, so there's no reason to use system_nrt[_freezable]_wq.
Please use system[_freezable]_wq instead.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-By: Lai Jiangshan <laijs@cn.fujitsu.com>

Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
2012-08-20 14:51:24 -07:00
Tejun Heo
41f63c5359 workqueue: use mod_delayed_work() instead of cancel + queue
Convert delayed_work users doing cancel_delayed_work() followed by
queue_delayed_work() to mod_delayed_work().

Most conversions are straight-forward.  Ones worth mentioning are,

* drivers/edac/edac_mc.c: edac_mc_workq_setup() converted to always
  use mod_delayed_work() and cancel loop in
  edac_mc_reset_delay_period() is dropped.

* drivers/platform/x86/thinkpad_acpi.c: No need to remember whether
  watchdog is active or not.  @fan_watchdog_active and related code
  dropped.

* drivers/power/charger-manager.c: Seemingly a lot of
  delayed_work_pending() abuse going on here.
  [delayed_]work_pending() are unsynchronized and racy when used like
  this.  I converted one instance in fullbatt_handler().  Please
  conver the rest so that it invokes workqueue APIs for the intended
  target state rather than trying to game work item pending state
  transitions.  e.g. if timer should be modified - call
  mod_delayed_work(), canceled - call cancel_delayed_work[_sync]().

* drivers/thermal/thermal_sys.c: thermal_zone_device_set_polling()
  simplified.  Note that round_jiffies() calls in this function are
  meaningless.  round_jiffies() work on absolute jiffies not delta
  delay used by delayed_work.

v2: Tomi pointed out that __cancel_delayed_work() users can't be
    safely converted to mod_delayed_work().  They could be calling it
    from irq context and if that happens while delayed_work_timer_fn()
    is running, it could deadlock.  __cancel_delayed_work() users are
    dropped.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Roland Dreier <roland@kernel.org>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
2012-08-13 16:27:37 -07:00