As Al Viro points out, there is an unlikely, but possible race between
opening a file and setting a lease on it. generic_add_lease is done with
the i_lock held, but the inode->i_flock check in break_lease is
lockless. It's possible for another task doing an open to do the entire
pathwalk and call break_lease between the point where generic_add_lease
checks for a conflicting open and adds the lease to the list. If this
occurs, we can end up with a lease set on the file with a conflicting
open.
To guard against that, check again for a conflicting open after adding
the lease to the i_flock list. If the above race occurs, then we can
simply unwind the lease setting and return -EAGAIN.
Because we take dentry references and acquire write access on the file
before calling break_lease, we know that if the i_flock list is empty
when the open caller goes to check it then the necessary refcounts have
already been incremented. Thus the additional check for a conflicting
open will see that there is one and the setlease call will fail.
Cc: Bruce Fields <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@fieldses.org>
ENOSPC was being returned in slot_get inspite of successful
execution of the function. This patch fixes this return
code.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJTOOOnAAoJEHm+PkMAQRiGsBAH/2PAOL3TbOG6tEedxQrTwsr2
muRIRTVWawjT8/npbHupxGnAyAVdmdffBHpmCmcftKdKNryT3YZW8/JWoYc+WSlo
3vTDJHDOYAe6yCBjjhYwcu150THBQdOymOi5mbbclo0XWYG18jd3+abYprRH6SiD
XqNSzYqoiv91JHBAWKBIpo1cyRDuwoM7+jZ7gX41r2800EL7loY3e08cPDDNU6HA
CKaLXMwLwYTefE+Wnr+4UUr08NbNBbBUKLUSXVqKKIpd+MtbyhV1SnWzz8VQSkag
K/uzsnGnE7nrqoepMSx3nXxzOWxUSY2EMbwhEjaKK4xBq9C9pzv3sG/o2/IyopU=
=Nuom
-----END PGP SIGNATURE-----
Merge tag 'v3.14' into drm-intel-next-queued
Linux 3.14
The vt-d w/a merged late in 3.14-rc needs a bit of fine-tuning, hence
backmerge.
Conflicts:
drivers/gpu/drm/i915/i915_gem_gtt.c
drivers/gpu/drm/i915/intel_ddi.c
drivers/gpu/drm/i915/intel_dp.c
All trivial adjacent lines changed type conflicts, so trivial git
doesn't even show them in the merg commit.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Pull vfs fixes from Al Viro:
"Switch mnt_hash to hlist, turning the races between __lookup_mnt() and
hash modifications into false negatives from __lookup_mnt() (instead
of hangs)"
On the false negatives from __lookup_mnt():
"The *only* thing we care about is not getting stuck in __lookup_mnt().
If it misses an entry because something in front of it just got moved
around, etc, we are fine. We'll notice that mount_lock mismatch and
that'll be it"
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
switch mnt_hash to hlist
don't bother with propagate_mnt() unless the target is shared
keep shadowed vfsmounts together
resizable namespace.c hashes
Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.
Reported-by: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fixes RCU bug - walking through hlist is safe in face of element moves,
since it's self-terminating. Cyclic lists are not - if we end up jumping
to another hash chain, we'll loop infinitely without ever hitting the
original list head.
[fix for dumb braino folded]
Spotted by: Max Kellermann <mk@cm4all.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If the dest_mnt is not shared, propagate_mnt() does nothing -
there's no mounts to propagate to and thus no copies to create.
Might as well don't bother calling it in that case.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch allocation to alloc_large_system_hash()
* make sizes overridable by boot parameters (mhash_entries=, mphash_entries=)
* switch mountpoint_hashtable from list_head to hlist_head
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Besides checking rpc_xprt out of xs_setup_bc_tcp,
increase it's reference (it's important).
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Testing NFS4.0 by pynfs, I got some messeages as,
"nfsd: inode locked twice during operation."
When one compound RPC contains two or more ops that locks
the filehandle,the second op will cause the message.
As two SETATTR ops, after the first SETATTR, nfsd will not call
fh_put() to release current filehandle, it means filehandle have
unlocked with fh_post_saved = 1.
The second SETATTR find fh_post_saved = 1, and printk the message.
v2: introduce helper fh_clear_wcc().
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
RFC5661 obsoletes NFS4ERR_STALE_STATEID in favour of NFS4ERR_BAD_STATEID.
Note that because nfsd encodes the clientid boot time in the stateid, we
can hit this error case in certain scenarios where the Linux client
state management thread exits early, before it has finished recovering
all state.
Reported-by: Idan Kedar <idank@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
encode_getattr, for example, can return nfserr_resource to indicate it
ran out of buffer space. That's not a legal error in the 4.1 case. And
in the 4.1 case, if we ran out of buffer space, we should have exceeded
a session limit too.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
cstate->slot and ->session are each set together in nfsd4_sequence. If
one is non-NULL, so is the other.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Connection from alloc_conn must be freed through free_conn,
otherwise, the reference of svc_xprt will never be put.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If we interrupt the nfs4_wait_for_completion_rpc_task() call in
nfs4_run_open_task(), then we don't prevent the RPC call from
completing. So freeing up the opendata->f_attr.mdsthreshold
in the error path in _nfs4_do_open() leads to a use-after-free
when the XDR decoder tries to decode the mdsthreshold information
from the server.
Fixes: 82be417aa3 (NFSv4.1 cache mdsthreshold values on OPEN)
Tested-by: Steve Dickson <SteveD@redhat.com>
Cc: stable@vger.kernel.org # 3.5+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Commit c74a3bdd9b ("ocfs2: add clustername to cluster connection") is
trying to strlcpy a string which was explicitly passed as NULL in the
very same patch, triggering a NULL ptr deref.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: strlcpy (lib/string.c:388 lib/string.c:151)
CPU: 19 PID: 19426 Comm: trinity-c19 Tainted: G W 3.14.0-rc7-next-20140325-sasha-00014-g9476368-dirty #274
RIP: strlcpy (lib/string.c:388 lib/string.c:151)
Call Trace:
ocfs2_cluster_connect (fs/ocfs2/stackglue.c:350)
ocfs2_cluster_connect_agnostic (fs/ocfs2/stackglue.c:396)
user_dlm_register (fs/ocfs2/dlmfs/userdlm.c:679)
dlmfs_mkdir (fs/ocfs2/dlmfs/dlmfs.c:503)
vfs_mkdir (fs/namei.c:3467)
SyS_mkdirat (fs/namei.c:3488 fs/namei.c:3472)
tracesys (arch/x86/kernel/entry_64.S:749)
akpm: this patch probably disables the feature. A temporary thing to
avoid triviel oopses.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reported by Tang Chen, Gu Zheng and Yasuaki Isimatsu, the following issues
exist in the aio ring page migration support.
As a result, for example, we have the following problem:
thread 1 | thread 2
|
aio_migratepage() |
|-> take ctx->completion_lock |
|-> migrate_page_copy(new, old) |
| *NOW*, ctx->ring_pages[idx] == old |
|
| *NOW*, ctx->ring_pages[idx] == old
| aio_read_events_ring()
| |-> ring = kmap_atomic(ctx->ring_pages[0])
| |-> ring->head = head; *HERE, write to the old ring page*
| |-> kunmap_atomic(ring);
|
|-> ctx->ring_pages[idx] = new |
| *BUT NOW*, the content of |
| ring_pages[idx] is old. |
|-> release ctx->completion_lock |
As above, the new ring page will not be updated.
Fix this issue, as well as prevent races in aio_ring_setup() by holding
the ring_lock mutex during kioctx setup and page migration. This avoids
the overhead of taking another spinlock in aio_read_events_ring() as Tang's
and Gu's original fix did, pushing the overhead into the migration code.
Note that to handle the nesting of ring_lock inside of mmap_sem, the
migratepage operation uses mutex_trylock(). Page migration is not a 100%
critical operation in this case, so the ocassional failure can be
tolerated. This issue was reported by Sasha Levin.
Based on feedback from Linus, avoid the extra taking of ctx->completion_lock.
Instead, make page migration fully serialised by mapping->private_lock, and
have aio_free_ring() simply disconnect the kioctx from the mapping by calling
put_aio_ring_file() before touching ctx->ring_pages[]. This simplifies the
error handling logic in aio_migratepage(), and should improve robustness.
v4: always do mutex_unlock() in cases when kioctx setup fails.
Reported-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: stable@vger.kernel.org
We have a WARN_ON in the nfsd4_decode_write() that tells us when the
client has sent a request that is not padded out properly according to
RFC4506. A WARN_ON really isn't appropriate in this case though since
this indicates a client bug, not a server one.
Move this check out to the top-level compound decoder and have it just
explicitly return an error. Also add a dprintk() that shows the client
address and xid to help track down clients and frames that trigger it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Looks like this bug has been here since these write counts were
introduced, not sure why it was just noticed now.
Thanks also to Jan Kara for pointing out the problem.
Cc: stable@vger.kernel.org
Reported-by: Matthew Rahtz <mrahtz@rapitasystems.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This fixes an ommission from 18032ca062
"NFSD: Server implementation of MAC Labeling", which increased the size
of the setattr error reply without increasing COMPOUND_ERR_SLACK_SPACE.
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If a client attempts to set an excessively large ACL, return
NFS4ERR_FBIG instead of NFS4ERR_RESOURCE. I'm not sure FBIG is correct,
but I'm positive RESOURCE is wrong (it isn't even a well-defined error
any more for NFS versions since 4.1).
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This was an omission from 8c18f2052e
"nfsd41: SUPPATTR_EXCLCREAT attribute".
Cc: Benny Halevy <bhalevy@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently we allocated anon_inode_inode in anon_inodefs_mount. This is
somewhat fragile as if that function ever gets called again, it will
overwrite anon_inode_inode pointer. So move the initialization of
anon_inode_inode to anon_inode_init().
Signed-off-by: Jan Kara <jack@suse.cz>
[ Further simplified on suggestion from Dave Jones ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit d1ba277e79.
As reported by Stephen, this patch breaks linux-next as a ppc patch
suddenly (after 2 years) started using this old api call. So revert it
for now, it will go away in 3.15-rc2 when we can change the PPC call to
the new api.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The previous commit removed the register_filesystem() call and the
associated error handling, but left the label for the error path that no
longer exists. Remove that too.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
anon_inodefs filesystem is a kernel internal filesystem userspace
shouldn't mess with. Remove registration of it so userspace cannot
even try to mount it (which would fail anyway because the filesystem is
MS_NOUSER).
This fixes an oops triggered by trinity when it tried mounting
anon_inodefs which overwrote anon_inode_inode pointer while other CPU
has been in anon_inode_getfile() between ihold() and d_instantiate().
Thus effectively creating dentry pointing to an inode without holding a
reference to it.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull nfsd fix frm Bruce Fields:
"J R Okajima sent this early and I was just slow to pass it along,
apologies. Fortunately it's a simple fix"
* 'nfsd-next' of git://linux-nfs.org/~bfields/linux:
nfsd: fix lost nfserrno() call in nfsd_setattr()
It's only called within inode.c, so make it static, remove its prototype
from ext4.h and move it above all of its callers so it doesn't need a
prototype within inode.c.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.
Reported-by: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Set a in-memory superblock flag to indicate whether the file system is
designed to support the Hurd.
Also, add a sanity check to make sure the 64-bit feature is not set
for Hurd file systems, since i_file_acl_high conflicts with a
Hurd-specific field.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Summary of http://lkml.org/lkml/2014/3/14/363 :
Ted: module_param(queue_depth, int, 444)
Joe: 0444!
Rusty: User perms >= group perms >= other perms?
Joe: CLASS_ATTR, DEVICE_ATTR, SENSOR_ATTR and SENSOR_ATTR_2?
Side effect of stricter permissions means removing the unnecessary
S_IFREG from several callers.
Note that the BUILD_BUG_ON_ZERO((perm) & 2) test was removed: a fair
number of drivers fail this test, so that will be the debate for a
future patch.
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> for drivers/pci/slot.c
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We can get false negative from __lookup_mnt() if an unrelated vfsmount
gets moved. In that case legitimize_mnt() is guaranteed to fail,
and we will fall back to non-RCU walk... unless we end up running
into a hard error on a filesystem object we wouldn't have reached
if not for that false negative. IOW, delaying that check until
the end of pathname resolution is wrong - we should recheck right
after we attempt to cross the mountpoint. We don't need to recheck
unless we see d_mountpoint() being true - in that case even if
we have just raced with mount/umount, we can simply go on as if
we'd come at the moment when the sucker wasn't a mountpoint; if we
run into a hard error as the result, it was a legitimate outcome.
__lookup_mnt() returning NULL is different in that respect, since
it might've happened due to operation on completely unrelated
mountpoint.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In all callchains leading to prepend_name(), the value left in *buflen
is eventually discarded unused if prepend_name() has returned a negative.
So we are free to do what prepend() does, and subtract from *buflen
*before* checking for underflow (which turns into checking the sign
of subtraction result, of course).
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit bd2a31d522 ("get rid of fget_light()") introduced the
__fdget_pos() function, which returns the resulting file pointer and
fdput flags combined in an 'unsigned long'. However, it also changed the
behavior to return files with FMODE_PATH set, which shouldn't happen
because read(), write(), lseek(), etc. aren't allowed on such files.
This commit restores the old behavior.
This regression actually had no effect on read() and write() since
FMODE_READ and FMODE_WRITE are not set on file descriptors opened with
O_PATH, but it did cause lseek() on a file descriptor opened with O_PATH
to fail with ESPIPE rather than EBADF.
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 9c225f2655 ("vfs: atomic f_pos accesses as per POSIX") changed
several system calls to use fdget_pos() instead of fdget(), but missed
sys_llseek(). Fix it.
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
