linux-toradex.git/fs/kernfs, branch v3.17-rc6

Merge 3.16-rc6 into driver-core-next

2014-07-21T17:07:25+00:00

We want the platform changes in here as well.

Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-07-10T18:38:23+00:00

Pull cgroup fixes from Tejun Heo:
 "Mostly fixes for the fallouts from the recent cgroup core changes.

  The decoupled nature of cgroup dynamic hierarchy management
  (hierarchies are created dynamically on mount but may or may not be
  reused once unmounted depending on remaining usages) led to more
  ugliness being added to kernfs.

  Hopefully, this is the last of it"

* 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: break kernfs active protection in cpuset_write_resmask()
  cgroup: fix a race between cgroup_mount() and cgroup_kill_sb()
  kernfs: introduce kernfs_pin_sb()
  cgroup: fix mount failure in a corner case
  cpuset,mempolicy: fix sleeping function called from invalid context
  cgroup: fix broken css_has_online_children()

kernfs: kernel-doc warning fix

2014-07-09T23:37:29+00:00

s/static_name/name_is_static

Signed-off-by: Fabian Frederick 
Acked-by: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

kernfs: kernfs_notify() must be useable from non-sleepable contexts

2014-07-02T16:32:09+00:00

d911d9874801 ("kernfs: make kernfs_notify() trigger inotify events
too") added fsnotify triggering to kernfs_notify() which requires a
sleepable context.  There are already existing users of
kernfs_notify() which invoke it from an atomic context and in general
it's silly to require a sleepable context for triggering a
notification.

The following is an invalid context bug triggerd by md invoking
sysfs_notify() from IO completion path.

 BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586
 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1
 2 locks held by swapper/1/0:
  #0:  (&(&vblk->vq_lock)->rlock){-.-...}, at: [] virtblk_done+0x42/0xe0 [virtio_blk]
  #1:  (&(&bitmap->counts.lock)->rlock){-.....}, at: [] bitmap_endwrite+0x68/0x240
 irq event stamp: 33518
 hardirqs last  enabled at (33515): [] default_idle+0x1f/0x230
 hardirqs last disabled at (33516): [] common_interrupt+0x6d/0x72
 softirqs last  enabled at (33518): [] _local_bh_enable+0x22/0x50
 softirqs last disabled at (33517): [] irq_enter+0x60/0x80
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.16.0-0.rc2.git2.1.fc21.x86_64 #1
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  0000000000000000 f90db13964f4ee05 ffff88007d403b80 ffffffff81807b4c
  0000000000000000 ffff88007d403ba8 ffffffff810d4f14 0000000000000000
  0000000000441800 ffff880078fa1780 ffff88007d403c38 ffffffff8180caf2
 Call Trace:
    [] dump_stack+0x4d/0x66
  [] __might_sleep+0x184/0x240
  [] mutex_lock_nested+0x42/0x440
  [] kernfs_notify+0x90/0x150
  [] bitmap_endwrite+0xcc/0x240
  [] close_write+0x93/0xb0 [raid1]
  [] r1_bio_write_done+0x29/0x50 [raid1]
  [] raid1_end_write_request+0xe4/0x260 [raid1]
  [] bio_endio+0x6b/0xa0
  [] blk_update_request+0x94/0x420
  [] blk_mq_end_io+0x1a/0x70
  [] virtblk_request_done+0x32/0x80 [virtio_blk]
  [] __blk_mq_complete_request+0x88/0x120
  [] blk_mq_complete_request+0x2a/0x30
  [] virtblk_done+0x66/0xe0 [virtio_blk]
  [] vring_interrupt+0x3a/0xa0 [virtio_ring]
  [] handle_irq_event_percpu+0x77/0x340
  [] handle_irq_event+0x3d/0x60
  [] handle_edge_irq+0x66/0x130
  [] handle_irq+0x84/0x150
  [] do_IRQ+0x4d/0xe0
  [] common_interrupt+0x72/0x72
    [] ? native_safe_halt+0x6/0x10
  [] default_idle+0x24/0x230
  [] arch_cpu_idle+0xf/0x20
  [] cpu_startup_entry+0x37c/0x7b0
  [] start_secondary+0x25b/0x300

This patch fixes it by punting the notification delivery through a
work item.  This ends up adding an extra pointer to kernfs_elem_attr
enlarging kernfs_node by a pointer, which is not ideal but not a very
big deal either.  If this turns out to be an actual issue, we can move
kernfs_elem_attr->size to kernfs_node->iattr later.

Signed-off-by: Tejun Heo 
Reported-by: Josh Boyer 
Cc: Jens Axboe 
Reviewed-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman

kernfs: introduce kernfs_pin_sb()

2014-06-30T14:16:25+00:00

kernfs_pin_sb() tries to get a refcnt of the superblock.

This will be used by cgroupfs.

v2:
- make kernfs_pin_sb() return the superblock.
- drop kernfs_drop_sb().

tj: Updated the comment a bit.

[ This is a prerequisite for a bugfix. ]
Cc:  # 3.15
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Li Zefan 
Signed-off-by: Tejun Heo

kernfs: move the last knowledge of sysfs out from kernfs

2014-05-27T21:33:17+00:00

There is still one residue of sysfs remaining: the sb_magic
SYSFS_MAGIC. However this should be kernfs user specific,
so this patch moves it out. Kerrnfs user should specify their
magic number while mouting.

Signed-off-by: Jianyu Zhan 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

Merge 3.15-rc6 into driver-core-next

2014-05-23T01:13:53+00:00

We want the kernfs fixes in this branch as well for testing.

Signed-off-by: Greg Kroah-Hartman

kernfs, sysfs, cgroup: restrict extra perm check on open to sysfs

2014-05-13T11:21:40+00:00

The kernfs open method - kernfs_fop_open() - inherited extra
permission checks from sysfs.  While the vfs layer allows ignoring the
read/write permissions checks if the issuer has CAP_DAC_OVERRIDE,
sysfs explicitly denied open regardless of the cap if the file doesn't
have any of the UGO perms of the requested access or doesn't implement
the requested operation.  It can be debated whether this was a good
idea or not but the behavior is too subtle and dangerous to change at
this point.

After cgroup got converted to kernfs, this extra perm check also got
applied to cgroup breaking libcgroup which opens write-only files with
O_RDWR as root.  This patch gates the extra open permission check with
a new flag KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK and enables it for sysfs.
For sysfs, nothing changes.  For cgroup, root now can perform any
operation regardless of the permissions as it was before kernfs
conversion.  Note that kernfs still fails unimplemented operations
with -EINVAL.

While at it, add comments explaining KERNFS_ROOT flags.

Signed-off-by: Tejun Heo 
Reported-by: Andrey Wagin 
Tested-by: Andrey Wagin 
Cc: Li Zefan 
References: http://lkml.kernel.org/g/CANaxB-xUm3rJ-Cbp72q-rQJO5mZe1qK6qXsQM=vh0U8upJ44+A@mail.gmail.com
Fixes: 2bd59d48ebfb ("cgroup: convert to kernfs")
Signed-off-by: Greg Kroah-Hartman

Merge 3.15-rc3 into staging-next

2014-04-28T04:36:39+00:00

kernfs: add back missing error check in kernfs_fop_mmap()

2014-04-25T19:25:13+00:00

While updating how mmap enabled kernfs files are handled by lockdep,
9b2db6e18945 ("sysfs: bail early from kernfs_file_mmap() to avoid
spurious lockdep warning") inadvertently dropped error return check
from kernfs_file_mmap().  The intention was just dropping "if
(ops->mmap)" check as the control won't reach the point if the mmap
callback isn't implemented, but I mistakenly removed the error return
check together with it.

This led to Xorg crash on i810 which was reported and bisected to the
commit and then to the specific change by Tobias.

Signed-off-by: Tejun Heo 
Reported-and-bisected-by: Tobias Powalowski 
Tested-by: Tobias Powalowski 
References: http://lkml.kernel.org/g/533D01BD.1010200@googlemail.com
Cc: stable  # 3.14
Signed-off-by: Greg Kroah-Hartman