Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
12 个月 前同步成功

通知 152
Star 36
Fork 7
cloud-kernel
cloud-kernel

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 14 12月, 2016 1 次提交
    • N
      block_dev: don't test bdev->bd_contains when it is not stable · bcc7f5b4
      由 NeilBrown 提交于 
      bdev->bd_contains is not stable before calling __blkdev_get().
When __blkdev_get() is called on a parition with ->bd_openers == 0
it sets
  bdev->bd_contains = bdev;
which is not correct for a partition.
After a call to __blkdev_get() succeeds, ->bd_openers will be > 0
and then ->bd_contains is stable.

When FMODE_EXCL is used, blkdev_get() calls
   bd_start_claiming() ->  bd_prepare_to_claim() -> bd_may_claim()

This call happens before __blkdev_get() is called, so ->bd_contains
is not stable.  So bd_may_claim() cannot safely use ->bd_contains.
It currently tries to use it, and this can lead to a BUG_ON().

This happens when a whole device is already open with a bd_holder (in
use by dm in my particular example) and two threads race to open a
partition of that device for the first time, one opening with O_EXCL and
one without.

The thread that doesn't use O_EXCL gets through blkdev_get() to
__blkdev_get(), gains the ->bd_mutex, and sets bdev->bd_contains = bdev;

Immediately thereafter the other thread, using FMODE_EXCL, calls
bd_start_claiming() from blkdev_get().  This should fail because the
whole device has a holder, but because bdev->bd_contains == bdev
bd_may_claim() incorrectly reports success.
This thread continues and blocks on bd_mutex.

The first thread then sets bdev->bd_contains correctly and drops the mutex.
The thread using FMODE_EXCL then continues and when it calls bd_may_claim()
again in:
			BUG_ON(!bd_may_claim(bdev, whole, holder));
The BUG_ON fires.

Fix this by removing the dependency on ->bd_contains in
bd_may_claim().  As bd_may_claim() has direct access to the whole
device, it can simply test if the target bdev is the whole device.

Fixes: 6b4517a7 ("block: implement bd_claiming and claiming block")
Cc: stable@vger.kernel.org (v2.6.35+)
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>
      bcc7f5b4
  3. 13 12月, 2016 24 次提交
  5. 08 12月, 2016 1 次提交
    • J
      ceph: don't set req->r_locked_dir in ceph_d_revalidate · c3f4688a
      由 Jeff Layton 提交于 
      This function sets req->r_locked_dir which is supposed to indicate to
ceph_fill_trace that the parent's i_rwsem is locked for write.
Unfortunately, there is no guarantee that the dir will be locked when
d_revalidate is called, so we really don't want ceph_fill_trace to do
any dcache manipulation from this context. Clear req->r_locked_dir since
it's clearly not safe to do that.

What we really want to know with d_revalidate is whether the dentry
still points to the same inode. ceph_fill_trace installs a pointer to
the inode in req->r_target_inode, so we can just compare that to
d_inode(dentry) to see if it's the same one after the lookup.

Also, since we aren't generally interested in the parent here, we can
switch to using a GETATTR to hint that to the MDS, which also means that
we only need to reserve one cap.

Finally, just remove the d_unhashed check. That's really outside the
purview of a filesystem's d_revalidate. If the thing became unhashed
while we're checking it, then that's up to the VFS to handle anyway.

Fixes: 200fd27c ("ceph: use lookup request to revalidate dentry")
Link: http://tracker.ceph.com/issues/18041Reported-by: NDonatas Abraitis <donatas.abraitis@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: N"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      c3f4688a
  7. 06 12月, 2016 1 次提交
    • M
      fuse: fix clearing suid, sgid for chown() · c01638f5
      由 Miklos Szeredi 提交于 
      Basically, the pjdfstests set the ownership of a file to 06555, and then
chowns it (as root) to a new uid/gid. Prior to commit a09f99ed ("fuse:
fix killing s[ug]id in setattr"), fuse would send down a setattr with both
the uid/gid change and a new mode.  Now, it just sends down the uid/gid
change.

Technically this is NOTABUG, since POSIX doesn't _require_ that we clear
these bits for a privileged process, but Linux (wisely) has done that and I
think we don't want to change that behavior here.

This is caused by the use of should_remove_suid(), which will always return
0 when the process has CAP_FSETID.

In fact we really don't need to be calling should_remove_suid() at all,
since we've already been indicated that we should remove the suid, we just
don't want to use a (very) stale mode for that.

This patch should fix the above as well as simplify the logic.

Reported-by: Jeff Layton <jlayton@redhat.com> 
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Fixes: a09f99ed ("fuse: fix killing s[ug]id in setattr")
Cc: <stable@vger.kernel.org>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
      c01638f5
  9. 01 12月, 2016 2 次提交
    • R
      block: protect iterate_bdevs() against concurrent close · af309226
      由 Rabin Vincent 提交于 
      If a block device is closed while iterate_bdevs() is handling it, the
following NULL pointer dereference occurs because bdev->b_disk is NULL
in bdev_get_queue(), which is called from blk_get_backing_dev_info() (in
turn called by the mapping_cap_writeback_dirty() call in
__filemap_fdatawrite_range()):

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000508
 IP: [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20
 PGD 9e62067 PUD 9ee8067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 1 PID: 2422 Comm: sync Not tainted 4.5.0-rc7+ #400
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
 task: ffff880009f4d700 ti: ffff880009f5c000 task.ti: ffff880009f5c000
 RIP: 0010:[<ffffffff81314790>]  [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20
 RSP: 0018:ffff880009f5fe68  EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff88000ec17a38 RCX: ffffffff81a4e940
 RDX: 7fffffffffffffff RSI: 0000000000000000 RDI: ffff88000ec176c0
 RBP: ffff880009f5fe68 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88000ec17860
 R13: ffffffff811b25c0 R14: ffff88000ec178e0 R15: ffff88000ec17a38
 FS:  00007faee505d700(0000) GS:ffff88000fb00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000508 CR3: 0000000009e8a000 CR4: 00000000000006e0
 Stack:
  ffff880009f5feb8 ffffffff8112e7f5 0000000000000000 7fffffffffffffff
  0000000000000000 0000000000000000 7fffffffffffffff 0000000000000001
  ffff88000ec178e0 ffff88000ec17860 ffff880009f5fec8 ffffffff8112e81f
 Call Trace:
  [<ffffffff8112e7f5>] __filemap_fdatawrite_range+0x85/0x90
  [<ffffffff8112e81f>] filemap_fdatawrite+0x1f/0x30
  [<ffffffff811b25d6>] fdatawrite_one_bdev+0x16/0x20
  [<ffffffff811bc402>] iterate_bdevs+0xf2/0x130
  [<ffffffff811b2763>] sys_sync+0x63/0x90
  [<ffffffff815d4272>] entry_SYSCALL_64_fastpath+0x12/0x76
 Code: 0f 1f 44 00 00 48 8b 87 f0 00 00 00 55 48 89 e5 <48> 8b 80 08 05 00 00 5d
 RIP  [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20
  RSP <ffff880009f5fe68>
 CR2: 0000000000000508
 ---[ end trace 2487336ceb3de62d ]---

The crash is easily reproducible by running the following command, if an
msleep(100) is inserted before the call to func() in iterate_devs():

 while :; do head -c1 /dev/nullb0; done > /dev/null & while :; do sync; done

Fix it by holding the bd_mutex across the func() call and only calling
func() if the bdev is opened.

Cc: stable@vger.kernel.org
Fixes: 5c0d6b60 ("vfs: Create function for iterating over block devices")
Reported-and-tested-by: NWei Fang <fangwei1@huawei.com>
Signed-off-by: NRabin Vincent <rabinv@axis.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>
      af309226
    • M
      isofs: add KERN_CONT to printing of ER records · a107bf8b
      由 Mike Rapoport 提交于 
      The ER records are printed without explicit log level presuming line
continuation until "\n".  After the commit 4bcc595c (printk:
reinstate KERN_CONT for printing continuation lines), the ER records are
printed a character per line.

Adding KERN_CONT to appropriate printk statements restores the printout
behavior.
Signed-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a107bf8b
  11. 30 11月, 2016 1 次提交
  13. 29 11月, 2016 4 次提交
    • M
      ovl: fix d_real() for stacked fs · c4fcfc16
      由 Miklos Szeredi 提交于 
      Handling of recursion in d_real() is completely broken.  Recursion is only
done in the 'inode != NULL' case.  But when opening the file we have
'inode == NULL' hence d_real() will return an overlay dentry.  This won't
work since overlayfs doesn't define its own file operations, so all file
ops will fail.

Fix by doing the recursion first and the check against the inode second.

Bash script to reproduce the issue written by Quentin:

 - 8< - - - - - 8< - - - - - 8< - - - - - 8< - - - -
tmpdir=$(mktemp -d)
pushd ${tmpdir}

mkdir -p {upper,lower,work}
echo -n 'rocks' > lower/ksplice
mount -t overlay level_zero upper -o lowerdir=lower,upperdir=upper,workdir=work
cat upper/ksplice

tmpdir2=$(mktemp -d)
pushd ${tmpdir2}

mkdir -p {upper,work}
mount -t overlay level_one upper -o lowerdir=${tmpdir}/upper,upperdir=upper,workdir=work
ls -l upper/ksplice
cat upper/ksplice
 - 8< - - - - - 8< - - - - - 8< - - - - - 8< - - - - 
Reported-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Fixes: 2d902671 ("vfs: merge .d_select_inode() into .d_real()")
Cc: <stable@vger.kernel.org> # v4.8+
      c4fcfc16
    • E
      CIFS: iterate over posix acl xattr entry correctly in ACL_to_cifs_posix() · ae9ebe7c
      由 Eryu Guan 提交于 
      Commit 2211d5ba ("posix_acl: xattr representation cleanups")
removes the typedefs and the zero-length a_entries array in struct
posix_acl_xattr_header, and uses bare struct posix_acl_xattr_header
and struct posix_acl_xattr_entry directly.

But it failed to iterate over posix acl slots when converting posix
acls to CIFS format, which results in several test failures in
xfstests (generic/053 generic/105) when testing against a samba v1
server, starting from v4.9-rc1 kernel. e.g.

  [root@localhost xfstests]# diff -u tests/generic/105.out /root/xfstests/results//generic/105.out.bad
  --- tests/generic/105.out       2016-09-19 16:33:28.577962575 +0800
  +++ /root/xfstests/results//generic/105.out.bad 2016-10-22 15:41:15.201931110 +0800
  @@ -1,3 +1,4 @@
   QA output created by 105
   -rw-r--r-- root
  +setfacl: subdir: Invalid argument
   -rw-r--r-- root

Fix it by introducing a new "ace" var, like what
cifs_copy_posix_acl() does, and iterating posix acl xattr entries
over it in the for loop.
Signed-off-by: NEryu Guan <guaneryu@gmail.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
      ae9ebe7c
    • S
      Call echo service immediately after socket reconnect · b8c60012
      由 Sachin Prabhu 提交于 
      Commit 4fcd1813 ("Fix reconnect to not defer smb3 session reconnect
long after socket reconnect") changes the behaviour of the SMB2 echo
service and causes it to renegotiate after a socket reconnect. However
under default settings, the echo service could take up to 120 seconds to
be scheduled.

The patch forces the echo service to be called immediately resulting a
negotiate call being made immediately on reconnect.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
      b8c60012
    • S
      CIFS: Fix BUG() in calc_seckey() · 5f4b5569
      由 Sachin Prabhu 提交于 
      Andy Lutromirski's new virtually mapped kernel stack allocations moves
kernel stacks the vmalloc area. This triggers the bug
 kernel BUG at ./include/linux/scatterlist.h:140!
at calc_seckey()->sg_init()
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
      5f4b5569
  15. 27 11月, 2016 1 次提交
  17. 23 11月, 2016 1 次提交
    • A
      NFSv4.x: hide array-bounds warning · d55b352b
      由 Arnd Bergmann 提交于 
      A correct bugfix introduced a harmless warning that shows up with gcc-7:

fs/nfs/callback.c: In function 'nfs_callback_up':
fs/nfs/callback.c:214:14: error: array subscript is outside array bounds [-Werror=array-bounds]

What happens here is that the 'minorversion == 0' check tells the
compiler that we assume minorversion can be something other than 0,
but when CONFIG_NFS_V4_1 is disabled that would be invalid and
result in an out-of-bounds access.

The added check for IS_ENABLED(CONFIG_NFS_V4_1) tells gcc that this
really can't happen, which makes the code slightly smaller and also
avoids the warning.

The bugfix that introduced the warning is marked for stable backports,
we want this one backported to the same releases.

Fixes: 98b0f80c ("NFSv4.x: Fix a refcount leak in nfs_callback_up_net")
Cc: stable@vger.kernel.org # v3.7+
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
      d55b352b
  19. 22 11月, 2016 4 次提交