linux.git/fs/ceph, branch v5.4

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

ceph: return -EINVAL if given fsc mount option on kernel w/o support

2019-11-07T17:03:23+00:00

If someone requests fscache on the mount, and the kernel doesn't
support it, it should fail the mount.

[ Drop ceph prefix -- it's provided by pr_err. ]

Signed-off-by: Jeff Layton 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Ilya Dryomov

ceph: don't allow copy_file_range when stripe_count != 1

2019-11-05T14:42:58+00:00

copy_file_range tries to use the OSD 'copy-from' operation, which simply
performs a full object copy.  Unfortunately, the implementation of this
system call assumes that stripe_count is always set to 1 and doesn't take
into account that the data may be striped across an object set.  If the
file layout has stripe_count different from 1, then the destination file
data will be corrupted.

For example:

Consider a 8 MiB file with 4 MiB object size, stripe_count of 2 and
stripe_size of 2 MiB; the first half of the file will be filled with 'A's
and the second half will be filled with 'B's:

               0      4M     8M       Obj1     Obj2
               +------+------+       +----+   +----+
        file:  | AAAA | BBBB |       | AA |   | AA |
               +------+------+       |----|   |----|
                                     | BB |   | BB |
                                     +----+   +----+

If we copy_file_range this file into a new file (which needs to have the
same file layout!), then it will start by copying the object starting at
file offset 0 (Obj1).  And then it will copy the object starting at file
offset 4M -- which is Obj1 again.

Unfortunately, the solution for this is to not allow remote object copies
to be performed when the file layout stripe_count is not 1 and simply
fallback to the default (VFS) copy_file_range implementation.

Cc: stable@vger.kernel.org
Signed-off-by: Luis Henriques 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: don't try to handle hashed dentries in non-O_CREAT atomic_open

2019-11-05T14:42:44+00:00

If ceph_atomic_open is handed a !d_in_lookup dentry, then that means
that it already passed d_revalidate so we *know* that it's negative (or
at least was very recently). Just return -ENOENT in that case.

This also addresses a subtle bug in dentry handling. Non-O_CREAT opens
call atomic_open with the parent's i_rwsem shared, but calling
d_splice_alias on a hashed dentry requires the exclusive lock.

If ceph_atomic_open receives a hashed, negative dentry on a non-O_CREAT
open, and another client were to race in and create the file before we
issue our OPEN, ceph_fill_trace could end up calling d_splice_alias on
the dentry with the new inode with insufficient locks.

Cc: stable@vger.kernel.org
Reported-by: Al Viro 
Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: add missing check in d_revalidate snapdir handling

2019-10-29T21:29:55+00:00

We should not play with dcache without parent locked...

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro 
Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: fix RCU case handling in ceph_d_revalidate()

2019-10-29T21:29:54+00:00

For RCU case ->d_revalidate() is called with rcu_read_lock() and
without pinning the dentry passed to it.  Which means that it
can't rely upon ->d_inode remaining stable; that's the reason
for d_inode_rcu(), actually.

Make sure we don't reload ->d_inode there.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro 
Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: fix use-after-free in __ceph_remove_cap()

2019-10-29T21:29:51+00:00

KASAN reports a use-after-free when running xfstest generic/531, with the
following trace:

[  293.903362]  kasan_report+0xe/0x20
[  293.903365]  rb_erase+0x1f/0x790
[  293.903370]  __ceph_remove_cap+0x201/0x370
[  293.903375]  __ceph_remove_caps+0x4b/0x70
[  293.903380]  ceph_evict_inode+0x4e/0x360
[  293.903386]  evict+0x169/0x290
[  293.903390]  __dentry_kill+0x16f/0x250
[  293.903394]  dput+0x1c6/0x440
[  293.903398]  __fput+0x184/0x330
[  293.903404]  task_work_run+0xb9/0xe0
[  293.903410]  exit_to_usermode_loop+0xd3/0xe0
[  293.903413]  do_syscall_64+0x1a0/0x1c0
[  293.903417]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

This happens because __ceph_remove_cap() may queue a cap release
(__ceph_queue_cap_release) which can be scheduled before that cap is
removed from the inode list with

	rb_erase(&cap->ci_node, &ci->i_caps);

And, when this finally happens, the use-after-free will occur.

This can be fixed by removing the cap from the inode list before being
removed from the session list, and thus eliminating the risk of an UAF.

Cc: stable@vger.kernel.org
Signed-off-by: Luis Henriques 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: just skip unrecognized info in ceph_reply_info_extra

2019-10-15T15:43:10+00:00

In the future, we're going to want to extend the ceph_reply_info_extra
for create replies. Currently though, the kernel code doesn't accept an
extra blob that is larger than the expected data.

Change the code to skip over any unrecognized fields at the end of the
extra blob, rather than returning -EIO.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

Merge tag 'ceph-for-5.4-rc1' of git://github.com/ceph/ceph-client

2019-09-25T17:21:13+00:00

Pull ceph updates from Ilya Dryomov:
 "The highlights are:

   - automatic recovery of a blacklisted filesystem session (Zheng Yan).
     This is disabled by default and can be enabled by mounting with the
     new "recover_session=clean" option.

   - serialize buffered reads and O_DIRECT writes (Jeff Layton). Care is
     taken to avoid serializing O_DIRECT reads and writes with each
     other, this is based on the exclusion scheme from NFS.

   - handle large osdmaps better in the face of fragmented memory
     (myself)

   - don't limit what security.* xattrs can be get or set (Jeff Layton).
     We were overly restrictive here, unnecessarily preventing things
     like file capability sets stored in security.capability from
     working.

   - allow copy_file_range() within the same inode and across different
     filesystems within the same cluster (Luis Henriques)"

* tag 'ceph-for-5.4-rc1' of git://github.com/ceph/ceph-client: (41 commits)
  ceph: call ceph_mdsc_destroy from destroy_fs_client
  libceph: use ceph_kvmalloc() for osdmap arrays
  libceph: avoid a __vmalloc() deadlock in ceph_kvmalloc()
  ceph: allow object copies across different filesystems in the same cluster
  ceph: include ceph_debug.h in cache.c
  ceph: move static keyword to the front of declarations
  rbd: pull rbd_img_request_create() dout out into the callers
  ceph: reconnect connection if session hang in opening state
  libceph: drop unused con parameter of calc_target()
  ceph: use release_pages() directly
  rbd: fix response length parameter for encoded strings
  ceph: allow arbitrary security.* xattrs
  ceph: only set CEPH_I_SEC_INITED if we got a MAC label
  ceph: turn ceph_security_invalidate_secctx into static inline
  ceph: add buffered/direct exclusionary locking for reads and writes
  libceph: handle OSD op ceph_pagelist_append() errors
  ceph: don't return a value from void function
  ceph: don't freeze during write page faults
  ceph: update the mtime when truncating up
  ceph: fix indentation in __get_snap_name()
  ...