linux-stable.git/fs/ceph, branch v5.4.34

ceph: canonicalize server path in place

2020-04-13T08:48:11+00:00

commit b27a939e8376a3f1ed09b9c33ef44d20f18ec3d0 upstream.

syzbot reported that 4fbc0c711b24 ("ceph: remove the extra slashes in
the server path") had caused a regression where an allocation could be
done under a spinlock -- compare_mount_options() is called by sget_fc()
with sb_lock held.

We don't really need the supplied server path, so canonicalize it
in place and compare it directly.  To make this work, the leading
slash is kept around and the logic in ceph_real_mount() to skip it
is restored.  CEPH_MSG_CLIENT_SESSION now reports the same (i.e.
canonicalized) path, with the leading slash of course.

Fixes: 4fbc0c711b24 ("ceph: remove the extra slashes in the server path")
Reported-by: syzbot+98704a51af8e3d9425a9@syzkaller.appspotmail.com
Signed-off-by: Ilya Dryomov 
Reviewed-by: Jeff Layton 
Signed-off-by: Luis Henriques 
Signed-off-by: Greg Kroah-Hartman

ceph: remove the extra slashes in the server path

2020-04-13T08:48:11+00:00

commit 4fbc0c711b2464ee1551850b85002faae0b775d5 upstream.

It's possible to pass the mount helper a server path that has more
than one contiguous slash character. For example:

  $ mount -t ceph 192.168.195.165:40176:/// /mnt/cephfs/

In the MDS server side the extra slashes of the server path will be
treated as snap dir, and then we can get the following debug logs:

  ceph:  mount opening path //
  ceph:  open_root_inode opening '//'
  ceph:  fill_trace 0000000059b8a3bc is_dentry 0 is_target 1
  ceph:  alloc_inode 00000000dc4ca00b
  ceph:  get_inode created new inode 00000000dc4ca00b 1.ffffffffffffffff ino 1
  ceph:  get_inode on 1=1.ffffffffffffffff got 00000000dc4ca00b

And then when creating any new file or directory under the mount
point, we can hit the following BUG_ON in ceph_fill_trace():

  BUG_ON(ceph_snap(dir) != dvino.snap);

Have the client ignore the extra slashes in the server path when
mounting. This will also canonicalize the path, so that identical mounts
can be consilidated.

1) "//mydir1///mydir//"
2) "/mydir1/mydir"
3) "/mydir1/mydir/"

Regardless of the internal treatment of these paths, the kernel still
stores the original string including the leading '/' for presentation
to userland.

URL: https://tracker.ceph.com/issues/42771
Signed-off-by: Xiubo Li 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Luis Henriques 
Signed-off-by: Greg Kroah-Hartman

ceph: fix memory leak in ceph_cleanup_snapid_map()

2020-04-01T09:01:59+00:00

commit c8d6ee01449cd0d2f30410681cccb616a88f50b1 upstream.

kmemleak reports the following memory leak:

unreferenced object 0xffff88821feac8a0 (size 96):
  comm "kworker/1:0", pid 17, jiffies 4294896362 (age 20.512s)
  hex dump (first 32 bytes):
    a0 c8 ea 1f 82 88 ff ff 00 c9 ea 1f 82 88 ff ff  ................
    00 00 00 00 00 00 00 00 00 01 00 00 00 00 ad de  ................
  backtrace:
    [<00000000b3ea77fb>] ceph_get_snapid_map+0x75/0x2a0
    [<00000000d4060942>] fill_inode+0xb26/0x1010
    [<0000000049da6206>] ceph_readdir_prepopulate+0x389/0xc40
    [<00000000e2fe2549>] dispatch+0x11ab/0x1521
    [<000000007700b894>] ceph_con_workfn+0xf3d/0x3240
    [<0000000039138a41>] process_one_work+0x24d/0x590
    [<00000000eb751f34>] worker_thread+0x4a/0x3d0
    [<000000007e8f0d42>] kthread+0xfb/0x130
    [<00000000d49bd1fa>] ret_from_fork+0x3a/0x50

A kfree is missing while looping the 'to_free' list of ceph_snapid_map
objects.

Cc: stable@vger.kernel.org
Fixes: 75c9627efb72 ("ceph: map snapid to anonymous bdev ID")
Signed-off-by: Luis Henriques 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

ceph: check POOL_FLAG_FULL/NEARFULL in addition to OSDMAP_FULL/NEARFULL

2020-04-01T09:01:58+00:00

commit 7614209736fbc4927584d4387faade4f31444fce upstream.

CEPH_OSDMAP_FULL/NEARFULL aren't set since mimic, so we need to consult
per-pool flags as well.  Unfortunately the backwards compatibility here
is lacking:

- the change that deprecated OSDMAP_FULL/NEARFULL went into mimic, but
  was guarded by require_osd_release >= RELEASE_LUMINOUS
- it was subsequently backported to luminous in v12.2.2, but that makes
  no difference to clients that only check OSDMAP_FULL/NEARFULL because
  require_osd_release is not client-facing -- it is for OSDs

Since all kernels are affected, the best we can do here is just start
checking both map flags and pool flags and send that to stable.

These checks are best effort, so take osdc->lock and look up pool flags
just once.  Remove the FIXME, since filesystem quotas are checked above
and RADOS quotas are reflected in POOL_FLAG_FULL: when the pool reaches
its quota, both POOL_FLAG_FULL and POOL_FLAG_FULL_QUOTA are set.

Cc: stable@vger.kernel.org
Reported-by: Yanhu Cao 
Signed-off-by: Ilya Dryomov 
Reviewed-by: Jeff Layton 
Acked-by: Sage Weil 
Signed-off-by: Greg Kroah-Hartman

ceph: do not execute direct write in parallel if O_APPEND is specified

2020-03-05T15:43:38+00:00

[ Upstream commit 8e4473bb50a1796c9c32b244e5dbc5ee24ead937 ]

In O_APPEND & O_DIRECT mode, the data from different writers will
be possibly overlapping each other since they take the shared lock.

For example, both Writer1 and Writer2 are in O_APPEND and O_DIRECT
mode:

          Writer1                         Writer2

     shared_lock()                   shared_lock()
     getattr(CAP_SIZE)               getattr(CAP_SIZE)
     iocb->ki_pos = EOF              iocb->ki_pos = EOF
     write(data1)
                                     write(data2)
     shared_unlock()                 shared_unlock()

The data2 will overlap the data1 from the same file offset, the
old EOF.

Switch to exclusive lock instead when O_APPEND is specified.

Signed-off-by: Xiubo Li 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: check availability of mds cluster on mount after wait timeout

2020-02-24T07:36:59+00:00

[ Upstream commit 97820058fb2831a4b203981fa2566ceaaa396103 ]

If all the MDS daemons are down for some reason, then the first mount
attempt will fail with EIO after the mount request times out.  A mount
attempt will also fail with EIO if all of the MDS's are laggy.

This patch changes the code to return -EHOSTUNREACH in these situations
and adds a pr_info error message to help the admin determine the cause.

URL: https://tracker.ceph.com/issues/4386
Signed-off-by: Xiubo Li 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin

ceph: hold extra reference to r_parent over life of request

2020-01-29T15:45:24+00:00

commit 9c1c2b35f1d94de8325344c2777d7ee67492db3b upstream.

Currently, we just assume that it will stick around by virtue of the
submitter's reference, but later patches will allow the syscall to
return early and we can't rely on that reference at that point.

While I'm not aware of any reports of it, Xiubo pointed out that this
may fix a use-after-free.  If the wait for a reply times out or is
canceled via signal, and then the reply comes in after the syscall
returns, the client can end up trying to access r_parent without a
reference.

Take an extra reference to the inode when setting r_parent and release
it when releasing the request.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton 
Reviewed-by: "Yan, Zheng" 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

ceph: fix compat_ioctl for ceph_dir_operations

2019-12-17T18:55:31+00:00

commit 18bd6caaef4021803dd0d031dc37c2d001d18a5b upstream.

The ceph_ioctl function is used both for files and directories, but only
the files support doing that in 32-bit compat mode.

On the s390 architecture, there is also a problem with invalid 31-bit
pointers that need to be passed through compat_ptr().

Use the new compat_ptr_ioctl() to address both issues.

Note: When backporting this patch to stable kernels, "compat_ioctl:
add compat_ptr_ioctl()" is needed as well.

Reviewed-by: "Yan, Zheng" 
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

ceph: increment/decrement dio counter on async requests

2019-11-14T17:44:51+00:00

Ceph can in some cases issue an async DIO request, in which case we can
end up calling ceph_end_io_direct before the I/O is actually complete.
That may allow buffered operations to proceed while DIO requests are
still in flight.

Fix this by incrementing the i_dio_count when issuing an async DIO
request, and decrement it when tearing down the aio_req.

Fixes: 321fe13c9398 ("ceph: add buffered/direct exclusionary locking for reads and writes")
Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: take the inode lock before acquiring cap refs

2019-11-14T17:44:51+00:00

Most of the time, we (or the vfs layer) takes the inode_lock and then
acquires caps, but ceph_read_iter does the opposite, and that can lead
to a deadlock.

When there are multiple clients treading over the same data, we can end
up in a situation where a reader takes caps and then tries to acquire
the inode_lock. Another task holds the inode_lock and issues a request
to the MDS which needs to revoke the caps, but that can't happen until
the inode_lock is unwedged.

Fix this by having ceph_read_iter take the inode_lock earlier, before
attempting to acquire caps.

Fixes: 321fe13c9398 ("ceph: add buffered/direct exclusionary locking for reads and writes")
Link: https://tracker.ceph.com/issues/36348
Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov