commit 26c9cb668c upstream.
Mac requires the unicode flag to be set for cifs, even for the smb
echo request (which doesn't have strings).
Without this Mac rejects the periodic echo requests (when mounting
with cifs) that we use to check if server is down
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 38bd49064a upstream.
A signal can interrupt a SendReceive call which result in incoming
responses to the call being ignored. This is a problem for calls such as
open which results in the successful response being ignored. This
results in an open file resource on the server.
The patch looks into responses which were cancelled after being sent and
in case of successful open closes the open fids.
For this patch, the check is only done in SendReceive2()
RH-bz: 1403319
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 2211d5ba5c ("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: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Remove the global file_list_lock to simplify cifs/smb3 locking and
have spinlocks that more closely match the information they are
protecting.
Add new tcon->open_file_lock and file->file_info_lock spinlocks.
Locks continue to follow a heirachy,
cifs_socket --> cifs_ses --> cifs_tcon --> cifs_file
where global tcp_ses_lock still protects socket and cifs_ses, while the
the newer locks protect the lower level structure's information
(tcon and cifs_file respectively).
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
Remove the unnecessary typedefs and the zero-length a_entries array in
struct posix_acl_xattr_header.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull cifs iovec cleanups from Al Viro.
* 'sendmsg.cifs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
cifs: don't bother with kmap on read_pages side
cifs_readv_receive: use cifs_read_from_socket()
cifs: no need to wank with copying and advancing iovec on recvmsg side either
cifs: quit playing games with draining iovecs
cifs: merge the hash calculation helpers
Pull cifs xattr updates from Al Viro:
"This is the remaining parts of the xattr work - the cifs bits"
* 'for-cifs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
cifs: Switch to generic xattr handlers
cifs: Fix removexattr for os2.* xattrs
cifs: Check for equality with ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT
cifs: Fix xattr name checks
The two values ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT are meant to be
enumerations, not bits in a bit mask. Use '==' instead of '&' to check
for these values.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For interim responses we only need to parse a header and update
a number credits. Now it is done for all SMB2+ command except
SMB2_READ which is wrong. Fix this by adding such processing.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Tested-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
With CIFS_DEBUG_2 enabled, additional debug information is tracked inside each
mid_q_entry struct, however cifs_save_when_sent may use the mid_q_entry after it
has been freed from the appropriate callback if the transport layer has very low
latency. Holding the srv_mutex fixes this use-after-free, as cifs_save_when_sent
is called while the srv_mutex is held while the request is sent.
Signed-off-by: Christopher Oo <t-chriso@microsoft.com>
[MS-SMB] 2.2.4.5.2.1 states:
"ChallengeLength (1 byte): When the CAP_EXTENDED_SECURITY bit is set,
the server MUST set this value to zero and clients MUST ignore this
value."
Signed-off-by: Noel Power <noel.power@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Smatch complains because we dereference "ses->server" without checking
some lines earlier inside the call to get_next_mid(ses->server).
fs/cifs/cifssmb.c:4921 CIFSGetDFSRefer()
warn: variable dereferenced before check 'ses->server' (see line 4899)
There is only one caller for this function get_dfs_path() and it always
passes a non-null "ses->server" pointer so this NULL check can be
removed.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <smfrench@gmail.com>
that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Replace all __constant_foo to foo() except in smb2status.h (1700 lines to
update).
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Steve French <sfrench@samba.org>
Cc: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a bigger patch, but its size is mostly due to
a single change for how we check for remapping illegal characters
in file names - a lot of repeated, small changes to
the way callers request converting file names.
The final patch in the series does the following:
1) changes default behavior for cifs to be more intuitive.
Currently we do not map by default to seven reserved characters,
ie those valid in POSIX but not in NTFS/CIFS/SMB3/Windows,
unless a mount option (mapchars) is specified. Change this
to by default always map and map using the SFM maping
(like the Mac uses) unless the server negotiates the CIFS Unix
Extensions (like Samba does when mounting with the cifs protocol)
when the remapping of the characters is unnecessary. This should
help SMB3 mounts in particular since Samba will likely be
able to implement this mapping with its new "vfs_fruit" module
as it will be doing for the Mac.
2) if the user specifies the existing "mapchars" mount option then
use the "SFU" (Microsoft Services for Unix, SUA) style mapping of
the seven characters instead.
3) if the user specifies "nomapposix" then disable SFM/MAC style mapping
(so no character remapping would be used unless the user specifies
"mapchars" on mount as well, as above).
4) change all the places in the code that check for the superblock
flag on the mount which is set by mapchars and passed in on all
path based operation and change it to use a small function call
instead to set the mapping type properly (and check for the
mapping type in the cifs unicode functions)
Signed-off-by: Steve French <smfrench@gmail.com>
by filling the output buffer with a data got from a partially received
response and requesting the remaining data from the server. This is
suitable for non-signed connections.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
that let us know how many bytes we have already got before reconnect.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
and don't mix it with the number of bytes that was requested.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
If a server change maximum buffer size for write (wsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in iovec write. Fix this by checking wsize all the
time before repeating request in iovec write.
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
If wsize changes on reconnect we need to use new writedata structure
that for retrying.
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
The functionality provided by free_rsp_buf() is duplicated in a number
of places. Replace these instances with a call to free_rsp_buf().
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
xfstest 020 detected a problem with cifs xattr handling. When a file
had an empty xattr list, we returned success (with an empty xattr value)
on query of particular xattrs rather than returning ENODATA.
This patch fixes it so that query of an xattr returns ENODATA when the
xattr list is empty for the file.
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
In the event that a send fails in an uncached write, or we end up
needing to reissue it (-EAGAIN case), we'll kfree the wdata but
the pages currently leak.
Fix this by adding a new kref release routine for uncached writedata
that releases the pages, and have the uncached codepaths use that.
[original patch by Jeff modified to fix minor formatting problems]
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
The cifs_writedata code uses a single element trailing array, which
just adds unneeded complexity. Use a flexarray instead.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
Rename CIFSSMBOpen to CIFS_open and make it take
cifs_open_parms structure as a parm.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
Remove indentation, fix comment style, rename camel case
variables in preparation to make it work with cifs_open_parms
structure as a parm.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
setfacl over cifs mounts can remove the default ACL when setting the
(non-default part of) the ACL and vice versa (we were leaving at 0
rather than setting to -1 the count field for the unaffected
half of the ACL. For example notice the setfacl removed
the default ACL in this sequence:
steven@steven-GA-970A-DS3:~/cifs-2.6$ getfacl /mnt/test-dir ; setfacl
-m default:user:test:rwx,user:test:rwx /mnt/test-dir
getfacl: Removing leading '/' from absolute path names
user::rwx
group::r-x
other::r-x
default:user::rwx
default:user:test:rwx
default:group::r-x
default😷:rwx
default:other::r-x
steven@steven-GA-970A-DS3:~/cifs-2.6$ getfacl /mnt/test-dir
getfacl: Removing leading '/' from absolute path names
user::rwx
user:test:rwx
group::r-x
mask::rwx
other::r-x
CC: Stable <stable@kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Jeremy Allison <jra@samba.org>
An earlier patch allowed setting the per-file compression flag
"chattr +c filename"
on an smb2 or smb3 mount, and also allowed lsattr to return
whether a file on a cifs, or smb2/smb3 mount was compressed.
This patch extends the ability to set the per-file
compression flag to the cifs protocol, which uses a somewhat
different IOCTL mechanism than SMB2, although the payload
(the flags stored in the compression_state) are the same.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Windows 8 and later can create NFS symlinks (within reparse points)
which we were assuming were normal NTFS symlinks and thus reporting
corrupt paths for. Add check for reparse points to make sure that
they really are normal symlinks before we try to parse the pathname.
We also should not be parsing other types of reparse points (DFS
junctions etc) as if they were a symlink so return EOPNOTSUPP
on those. Also fix endian errors (we were not parsing symlink
lengths as little endian).
This fixes commit d244bf2dfb
which implemented follow link for non-Unix CIFS mounts
CC: Stable <stable@kernel.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Currently, we try to ensure that we use vcnum of 0 on the first
established session on a connection and then try to use a different
vcnum on each session after that.
This is a little odd, since there's no real reason to use a different
vcnum for each SMB session. I can only assume there was some confusion
between SMB sessions and VCs. That's somewhat understandable since they
both get created during SESSION_SETUP, but the documentation indicates
that they are really orthogonal. The comment on max_vcs in particular
looks quite misguided. An SMB session is already uniquely identified
by the SMB UID value -- there's no need to again uniquely ID with a
VC.
Furthermore, a vcnum of 0 is a cue to the server that it should release
any resources that were previously held by the client. This sounds like
a good thing, until you consider that:
a) it totally ignores the fact that other programs on the box (e.g.
smbclient) might have connections established to the server. Using a
vcnum of 0 causes them to get kicked off.
b) it causes problems with NAT. If several clients are connected to the
same server via the same NAT'ed address, whenever one connects to the
server it kicks off all the others, which then reconnect and kick off
the first one...ad nauseum.
I don't see any reason to ignore the advice in "Implementing CIFS" which
has a comprehensive treatment of virtual circuits. In there, it states
"...and contrary to the specs the client should always use a VcNumber of
one, never zero."
Have the client just use a hardcoded vcnum of 1, and stop abusing the
special behavior of vcnum 0.
Reported-by: Sauron99@gmx.de <sauron99@gmx.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
by using a query reparse ioctl request.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Currently the trans2 ByteCount field is incorrectly left zero in
TRANS2_QUERY_FILE_INFO info_level=SMB_QUERY_FILE_ALL_INFO and
info_level=SMB_QUERY_FILE_UNIX_BASIC requests. The field should properly
reflect the FID, information_level and padding bytes carried in these
requests.
Leaving this field zero causes such requests to fail against Novell CIFS
servers. Other SMB servers (e.g. Samba) use the parameter count fields
for data length calculations instead, so do not suffer the same fate.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Commit 9ddec56131 (cifs: move handling of signed connections into
separate function) broke signing on SMB2/3 connections. While the code
to enable signing on the connections was very similar between the two,
the bits that get set in the sec_mode are different.
Declare a couple of new smb_version_values fields and set them
appropriately for SMB1 and SMB2/3. Then change cifs_enable_signing to
use those instead.
Reported-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Now that we track what sort of NEGOTIATE response was received, stop
mandating that every session on a socket use the same type of auth.
Push that decision out into the session setup code, and make the sectype
a per-session property. This should allow us to mix multiple sectypes on
a socket as long as they are compatible with the NEGOTIATE response.
With this too, we can now eliminate the ses->secFlg field since that
info is redundant and harder to work with than a securityEnum.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
Currently, we determine this according to flags in the sec_mode, flags
in the global_secflags and via other methods. That makes the semantics
very hard to follow and there are corner cases where we don't handle
this correctly.
Add a new bool to the TCP_Server_Info that acts as a simple flag to tell
us whether signing is enabled on this connection or not, and fix up the
places that need to determine this to use that flag.
This is a bit weird for the SMB2 case, where signing is per-session.
SMB2 needs work in this area already though. The existing SMB2 code has
similar logic to what we're using here, so there should be no real
change in behavior. These changes should make it easier to implement
per-session signing in the future though.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
Track what sort of NEGOTIATE response we get from the server, as that
will govern what sort of authentication types this socket will support.
There are three possibilities:
LANMAN: server sent legacy LANMAN-type response
UNENCAP: server sent a newer-style response, but extended security bit
wasn't set. This socket will only support unencapsulated auth types.
EXTENDED: server sent a newer-style response with the extended security
bit set. This is necessary to support krb5 and ntlmssp auth types.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
Move the sanity checks for signed connections into a separate function.
SMB2's was a cut-and-paste job from CIFS code, so we can make them use
the same function.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
...this also gets rid of some #ifdef ugliness too.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...cleanup.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
These look pretty cargo-culty to me, but let's be certain. Leave
them in place for now. Pop a WARN if it ever does happen. Also,
move to a more standard idiom for setting the "server" pointer.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Currently, the signing routines take a pointer to a place to store the
expected sequence number for the mid response. It then stores a value
that's one below what that sequence number should be, and then adds one
to it when verifying the signature on the response.
Increment the sequence number before storing the value in the mid, and
eliminate the "+1" when checking the signature.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
It's not obvious from reading the macro names that these macros
are for debugging. Convert the names to a single more typical
kernel style cifs_dbg macro.
cERROR(1, ...) -> cifs_dbg(VFS, ...)
cFYI(1, ...) -> cifs_dbg(FYI, ...)
cFYI(DBG2, ...) -> cifs_dbg(NOISY, ...)
Move the terminating format newline from the macro to the call site.
Add CONFIG_CIFS_DEBUG function cifs_vfs_err to emit the
"CIFS VFS: " prefix for VFS messages.
Size is reduced ~ 1% when CONFIG_CIFS_DEBUG is set (default y)
$ size fs/cifs/cifs.ko*
text data bss dec hex filename
265245 2525 132 267902 4167e fs/cifs/cifs.ko.new
268359 2525 132 271016 422a8 fs/cifs/cifs.ko.old
Other miscellaneous changes around these conversions:
o Miscellaneous typo fixes
o Add terminating \n's to almost all formats and remove them
from the macros to be more kernel style like. A few formats
previously had defective \n's
o Remove unnecessary OOM messages as kmalloc() calls dump_stack
o Coalesce formats to make grep easier,
added missing spaces when coalescing formats
o Use %s, __func__ instead of embedded function name
o Removed unnecessary "cifs: " prefixes
o Convert kzalloc with multiply to kcalloc
o Remove unused cifswarn macro
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This replaces calls to kmalloc followed by memcpy with a single call to
kmemdup. This was found via make coccicheck.
Signed-off-by: Silviu-Mihai Popescu <silviupopescu1990@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
We had a recent fix to fix the release of pagecache pages when
cifs_writev_requeue writes fail. Unfortunately, it releases the page
before trying to unlock it. At that point, the page might be gone by the
time the unlock comes in.
Unlock the page first before checking the value of "rc", and only then
end writeback and release the pages. The page lock isn't required for
any of those operations so this should be safe.
Reported-by: Anton Altaparmakov <aia21@cam.ac.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>