Commit Graph

391 Commits

Author SHA1 Message Date
Pavel Shilovsky
e374d90f8a CIFS: Fix rsize usage for sync read
If a server changes maximum buffer size for read requests (rsize)
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in cifs_read. Fix this by checking rsize all the
time before repeating requests.

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:03 -05:00
Pavel Shilovsky
25f402598d CIFS: Fix rsize usage in user read
If a server changes maximum buffer size for read (rsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in user read. Fix this by checking rsize all the
time before repeating requests.

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:03 -05:00
Pavel Shilovsky
0ada36b244 CIFS: Separate page reading from user read
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:03 -05:00
Pavel Shilovsky
69cebd7560 CIFS: Fix rsize usage in readpages
If a server changes maximum buffer size for read (rsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in readpages. Fix this by checking rsize all the
time before repeating requests.

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:03 -05:00
Pavel Shilovsky
387eb92ac6 CIFS: Separate page search from readpages
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:03 -05:00
Pavel Shilovsky
cb7e9eabb2 CIFS: Use multicredits for SMB 2.1/3 writes
If we negotiate SMB 2.1 and higher version of the protocol and
a server supports large write buffer size, we need to consume 1
credit per 65536 bytes. So, we need to know how many credits
we have and obtain the required number of them before constructing
a writedata structure in writepages and 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>
2014-08-02 01:23:03 -05:00
Pavel Shilovsky
6ec0b01b26 CIFS: Fix wsize usage in iovec write
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>
2014-08-02 01:23:02 -05:00
Pavel Shilovsky
43de94eadf CIFS: Separate writing from 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>
2014-08-02 01:23:02 -05:00
Pavel Shilovsky
66386c08be CIFS: Separate filling pages from 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>
2014-08-02 01:23:02 -05:00
Pavel Shilovsky
66231a4796 CIFS: Fix wsize usage in writepages
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 writepages. Fix this by checking wsize all the
time before repeating request in writepages.

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:02 -05:00
Pavel Shilovsky
90ac1387c2 CIFS: Separate pages initialization from writepages
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:02 -05:00
Pavel Shilovsky
619aa48edb CIFS: Separate page sending from writepages
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:02 -05:00
Pavel Shilovsky
7e48ff8202 CIFS: Separate page processing from writepages
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:01 -05:00
Pavel Shilovsky
038bc961c3 CIFS: Fix async reading on reconnects
If we get into read_into_pages() from cifs_readv_receive() and then
loose a network, we issue cifs_reconnect that moves all mids to
a private list and issue their callbacks. The callback of the async
read request sets a mid to retry, frees it and wakes up a process
that waits on the rdata completion.

After the connection is established we return from read_into_pages()
with a short read, use the mid that was freed before and try to read
the remaining data from the a newly created socket. Both actions are
not what we want to do. In reconnect cases (-EAGAIN) we should not
mask off the error with a short read but should return the error
code instead.

Acked-by: Jeff Layton <jlayton@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:01 -05:00
Linus Torvalds
16b9057804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "This the bunch that sat in -next + lock_parent() fix.  This is the
  minimal set; there's more pending stuff.

  In particular, I really hope to get acct.c fixes merged this cycle -
  we need that to deal sanely with delayed-mntput stuff.  In the next
  pile, hopefully - that series is fairly short and localized
  (kernel/acct.c, fs/super.c and fs/namespace.c).  In this pile: more
  iov_iter work.  Most of prereqs for ->splice_write with sane locking
  order are there and Kent's dio rewrite would also fit nicely on top of
  this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (70 commits)
  lock_parent: don't step on stale ->d_parent of all-but-freed one
  kill generic_file_splice_write()
  ceph: switch to iter_file_splice_write()
  shmem: switch to iter_file_splice_write()
  nfs: switch to iter_splice_write_file()
  fs/splice.c: remove unneeded exports
  ocfs2: switch to iter_file_splice_write()
  ->splice_write() via ->write_iter()
  bio_vec-backed iov_iter
  optimize copy_page_{to,from}_iter()
  bury generic_file_aio_{read,write}
  lustre: get rid of messing with iovecs
  ceph: switch to ->write_iter()
  ceph_sync_direct_write: stop poking into iov_iter guts
  ceph_sync_read: stop poking into iov_iter guts
  new helper: copy_page_from_iter()
  fuse: switch to ->write_iter()
  btrfs: switch to ->write_iter()
  ocfs2: switch to ->write_iter()
  xfs: switch to ->write_iter()
  ...
2014-06-12 10:30:18 -07:00
Jeff Layton
4f73c7d342 cifs: fix potential races in cifs_revalidate_mapping
The handling of the CIFS_INO_INVALID_MAPPING flag is racy. It's possible
for two tasks to attempt to revalidate the mapping at the same time. The
first sees that CIFS_INO_INVALID_MAPPING is set. It clears the flag and
then calls invalidate_inode_pages2 to start shooting down the pagecache.

While that's going on, another task checks the flag and sees that it's
clear. It then ends up trusting the pagecache to satisfy a read when it
shouldn't.

Fix this by adding a bitlock to ensure that the clearing of the flag is
atomic with respect to the actual cache invalidation. Also, move the
other existing users of cifs_invalidate_mapping to use a new
cifs_zap_mapping() function that just sets the INVALID_MAPPING bit and
then uses the standard codepath to handle the invalidation.

Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-05-21 10:18:05 -07:00
Jeff Layton
aff8d5ca7a cifs: convert booleans in cifsInodeInfo to a flags field
In later patches, we'll need to have a bitlock, so go ahead and convert
these bools to use atomic bitops instead.

Also, clean up the initialization of the flags field. There's no need
to unset each bit individually just after it was zeroed on allocation.

Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-05-21 10:18:05 -07:00
Al Viro
3dae8750c3 cifs: switch to ->write_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:39:37 -04:00
Al Viro
e6a7bcb4c4 cifs: switch to ->read_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:37:58 -04:00
Al Viro
71d8e532b1 start adding the tag to iov_iter
For now, just use the same thing we pass to ->direct_IO() - it's all
iovec-based at the moment.  Pass it explicitly to iov_iter_init() and
account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO()
uses.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:49 -04:00
Al Viro
d8d3d94b80 pass iov_iter to ->direct_IO()
unmodified, for now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:44 -04:00
Al Viro
e7c24607b5 kill iov_iter_copy_from_user()
all callers can use copy_page_from_iter() and it actually simplifies
them.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:42 -04:00
Michael Opdenacker
1f80c0cc39 cif: fix dead code
This issue was found by Coverity (CID 1202536)

This proposes a fix for a statement that creates dead code.
The "rc < 0" statement is within code that is run
with "rc > 0".

It seems like "err < 0" was meant to be used here.
This way, the error code is returned by the function.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-04-16 23:08:57 -05:00
Jeff Layton
bae9f746a1 cifs: fix error handling cifs_user_readv
Coverity says:

*** CID 1202537:  Dereference after null check  (FORWARD_NULL)
/fs/cifs/file.c: 2873 in cifs_user_readv()
2867     		cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
2868     		npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2869
2870     		/* allocate a readdata struct */
2871     		rdata = cifs_readdata_alloc(npages,
2872     					    cifs_uncached_readv_complete);
>>>     CID 1202537:  Dereference after null check  (FORWARD_NULL)
>>>     Comparing "rdata" to null implies that "rdata" might be null.
2873     		if (!rdata) {
2874     			rc = -ENOMEM;
2875     			goto error;
2876     		}
2877
2878     		rc = cifs_read_allocate_pages(rdata, npages);

...when we "goto error", rc will be non-zero, and then we end up trying
to do a kref_put on the rdata (which is NULL). Fix this by replacing
the "goto error" with a "break".

Reported-by: <scan-admin@coverity.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-04-16 22:54:30 -05:00
Sachin Prabhu
c11f1df500 cifs: Wait for writebacks to complete before attempting write.
Problem reported in Red Hat bz 1040329 for strict writes where we cache
only when we hold oplock and write direct to the server when we don't.

When we receive an oplock break, we first change the oplock value for
the inode in cifsInodeInfo->oplock to indicate that we no longer hold
the oplock before we enqueue a task to flush changes to the backing
device. Once we have completed flushing the changes, we return the
oplock to the server.

There are 2 ways here where we can have data corruption
1) While we flush changes to the backing device as part of the oplock
break, we can have processes write to the file. These writes check for
the oplock, find none and attempt to write directly to the server.
These direct writes made while we are flushing from cache could be
overwritten by data being flushed from the cache causing data
corruption.
2) While a thread runs in cifs_strict_writev, the machine could receive
and process an oplock break after the thread has checked the oplock and
found that it allows us to cache and before we have made changes to the
cache. In that case, we end up with a dirty page in cache when we
shouldn't have any. This will be flushed later and will overwrite all
subsequent writes to the part of the file represented by this page.

Before making any writes to the server, we need to confirm that we are
not in the process of flushing data to the server and if we are, we
should wait until the process is complete before we attempt the write.
We should also wait for existing writes to complete before we process
an oplock break request which changes oplock values.

We add a version specific  downgrade_oplock() operation to allow for
differences in the oplock values set for the different smb versions.

Cc: stable@vger.kernel.org
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-04-16 13:51:46 -05:00
Geert Uytterhoeven
e686bd8dc5 cifs: Use min_t() when comparing "size_t" and "unsigned long"
On 32 bit, size_t is "unsigned int", not "unsigned long", causing the
following warning when comparing with PAGE_SIZE, which is always "unsigned
long":

  fs/cifs/file.c: In function ‘cifs_readdata_to_iov’:
  fs/cifs/file.c:2757: warning: comparison of distinct pointer types lacks a cast

Introduced by commit 7f25bba819 ("cifs_iovec_read: keep iov_iter
between the calls of cifs_readdata_to_iov()"), which changed the
signedness of "remaining" and the code from min_t() to min().

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-13 14:10:26 -07:00
Linus Torvalds
5166701b36 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The first vfs pile, with deep apologies for being very late in this
  window.

  Assorted cleanups and fixes, plus a large preparatory part of iov_iter
  work.  There's a lot more of that, but it'll probably go into the next
  merge window - it *does* shape up nicely, removes a lot of
  boilerplate, gets rid of locking inconsistencie between aio_write and
  splice_write and I hope to get Kent's direct-io rewrite merged into
  the same queue, but some of the stuff after this point is having
  (mostly trivial) conflicts with the things already merged into
  mainline and with some I want more testing.

  This one passes LTP and xfstests without regressions, in addition to
  usual beating.  BTW, readahead02 in ltp syscalls testsuite has started
  giving failures since "mm/readahead.c: fix readahead failure for
  memoryless NUMA nodes and limit readahead pages" - might be a false
  positive, might be a real regression..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  missing bits of "splice: fix racy pipe->buffers uses"
  cifs: fix the race in cifs_writev()
  ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
  kill generic_file_buffered_write()
  ocfs2_file_aio_write(): switch to generic_perform_write()
  ceph_aio_write(): switch to generic_perform_write()
  xfs_file_buffered_aio_write(): switch to generic_perform_write()
  export generic_perform_write(), start getting rid of generic_file_buffer_write()
  generic_file_direct_write(): get rid of ppos argument
  btrfs_file_aio_write(): get rid of ppos
  kill the 5th argument of generic_file_buffered_write()
  kill the 4th argument of __generic_file_aio_write()
  lustre: don't open-code kernel_recvmsg()
  ocfs2: don't open-code kernel_recvmsg()
  drbd: don't open-code kernel_recvmsg()
  constify blk_rq_map_user_iov() and friends
  lustre: switch to kernel_sendmsg()
  ocfs2: don't open-code kernel_sendmsg()
  take iov_iter stuff to mm/iov_iter.c
  process_vm_access: tidy up a bit
  ...
2014-04-12 14:49:50 -07:00
Al Viro
19dfc1f5f2 cifs: fix the race in cifs_writev()
O_APPEND handling there hadn't been completely fixed by Pavel's
patch; it checks the right value, but it's racy - we can't really
do that until i_mutex has been taken.

Fix by switching to __generic_file_aio_write() (open-coding
generic_file_aio_write(), actually) and pulling mutex_lock() above
inode_size_read().

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-12 06:52:48 -04:00
Kirill A. Shutemov
f1820361f8 mm: implement ->map_pages for page cache
filemap_map_pages() is generic implementation of ->map_pages() for
filesystems who uses page cache.

It should be safe to use filemap_map_pages() for ->map_pages() if
filesystem use filemap_fault() for ->fault().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ning Qu <quning@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:53 -07:00
Al Viro
0165e8100b fold cifs_iovec_read() into its (only) caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:24 -04:00
Al Viro
7f25bba819 cifs_iovec_read: keep iov_iter between the calls of cifs_readdata_to_iov()
... we are doing them on adjacent parts of file, so what happens is that
each subsequent call works to rebuild the iov_iter to exact state it
had been abandoned in by previous one.  Just keep it through the entire
cifs_iovec_read().  And use copy_page_to_iter() instead of doing
kmap/copy_to_user/kunmap manually...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:23 -04:00
Al Viro
74027f4a18 cifs_iovec_read(): resubmit shouldn't restart the loop
... by that point the request we'd just resent is in the
head of the list anyway.  Just return to the beginning of
the loop body...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:22 -04:00
Pavel Shilovsky
6b1168e161 CIFS: Fix wrong pos argument of cifs_find_lock_conflict
and use generic_file_aio_write rather than __generic_file_aio_write
in cifs_writev.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-02-23 20:54:50 -06:00
Linus Torvalds
351a7934c0 Merge branch 'for-linus' of git://git.samba.org/sfrench/cifs-2.6
Pull CIFS fixes from Steve French:
 "Three cifs fixes, the most important fixing the problem with passing
  bogus pointers with writev (CVE-2014-0069).

  Two additional cifs fixes are still in review (including the fix for
  an append problem which Al also discovered)"

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix too big maxBuf size for SMB3 mounts
  cifs: ensure that uncached writes handle unmapped areas correctly
  [CIFS] Fix cifsacl mounts over smb2 to not call cifs
2014-02-17 13:50:11 -08:00
Jeff Layton
5d81de8e86 cifs: ensure that uncached writes handle unmapped areas correctly
It's possible for userland to pass down an iovec via writev() that has a
bogus user pointer in it. If that happens and we're doing an uncached
write, then we can end up getting less bytes than we expect from the
call to iov_iter_copy_from_user. This is CVE-2014-0069

cifs_iovec_write isn't set up to handle that situation however. It'll
blindly keep chugging through the page array and not filling those pages
with anything useful. Worse yet, we'll later end up with a negative
number in wdata->tailsz, which will confuse the sending routines and
cause an oops at the very least.

Fix this by having the copy phase of cifs_iovec_write stop copying data
in this situation and send the last write as a short one. At the same
time, we want to avoid sending a zero-length write to the server, so
break out of the loop and set rc to -EFAULT if that happens. This also
allows us to handle the case where no address in the iovec is valid.

[Note: Marking this for stable on v3.4+ kernels, but kernels as old as
       v2.6.38 may have a similar problem and may need similar fix]

Cc: <stable@vger.kernel.org> # v3.4+
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-02-14 16:46:15 -06:00
Steve French
42eacf9e57 [CIFS] Fix cifsacl mounts over smb2 to not call cifs
When mounting with smb2/smb3 (e.g. vers=2.1) and cifsacl mount option,
it was trying to get the mode by querying the acl over the cifs
rather than smb2 protocol.  This patch makes that protocol
independent and makes cifsacl smb2 mounts return a more intuitive
operation not supported error (until we add a worker function
for smb2_get_acl).

Note that a previous patch fixed getxattr/setxattr for the CIFSACL xattr
which would unconditionally call cifs_get_acl and cifs_set_acl (even when
mounted smb2). I made those protocol independent last week (new protocol
version operations "get_acl" and "set_acl" but did not add an
smb2_get_acl and smb2_set_acl yet so those now simply return EOPNOTSUPP
which at least is better than sending cifs requests on smb2 mount)

The previous patches did not fix the one remaining case though ie
mounting with "cifsacl" when getting mode from acl would unconditionally
end up calling "cifs_get_acl_from_fid" even for smb2 - so made that protocol
independent but to make that protocol independent had to make sure that the callers
were passing the protocol independent handle structure (cifs_fid) instead
of cifs specific _u16 network file handle (ie cifs_fid instead of cifs_fid->fid)

Now mount with smb2 and cifsacl mount options will return EOPNOTSUP (instead
of timing out) and a future patch will add smb2 operations (e.g. get_smb2_acl)
to enable this.

Signed-off-by: Steve French <smfrench@gmail.com>
2014-02-10 14:08:16 -06:00
Linus Torvalds
cbf2822a7d Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull CIFS fixes from Steve French:
 "Small fix from Jeff for writepages leak, and some fixes for ACLs and
  xattrs when SMB2 enabled.

  Am expecting another fix from Jeff and at least one more fix (for
  mounting SMB2 with cifsacl) in the next week"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  [CIFS] clean up page array when uncached write send fails
  cifs: use a flexarray in cifs_writedata
  retrieving CIFS ACLs when mounted with SMB2 fails dropping session
  Add protocol specific operation for CIFS xattrs
2014-02-10 10:33:50 -08:00
Al Viro
d311d79de3 fix O_SYNC|O_APPEND syncing the wrong range on write()
It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
when sync_page_range() had been introduced; generic_file_write{,v}() correctly
synced
	pos_after_write - written .. pos_after_write - 1
but generic_file_aio_write() synced
	pos_before_write .. pos_before_write + written - 1
instead.  Which is not the same thing with O_APPEND, obviously.
A couple of years later correct variant had been killed off when
everything switched to use of generic_file_aio_write().

All users of generic_file_aio_write() are affected, and the same bug
has been copied into other instances of ->aio_write().

The fix is trivial; the only subtle point is that generic_write_sync()
ought to be inlined to avoid calculations useless for the majority of
calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-02-09 15:18:09 -05:00
Steve French
4a5c80d7b5 [CIFS] clean up page array when uncached write send fails
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>
2014-02-07 20:47:00 -06:00
Pavel Shilovsky
d81b8a40e2 CIFS: Cleanup cifs open codepath
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>
2014-01-20 09:52:13 -06:00
Steve French
dca692880e [CIFS] O_DIRECT opens should work on directio mounts
Opens on current cifs/smb2/smb3 mounts with O_DIRECT flag fail
even when caching is disabled on the mount.  This was
reported by those running SMB2 benchmarks who need to
be able to pass O_DIRECT on many of their open calls to
reduce caching effects, but would also be needed by other
applications.

When mounting with forcedirectio ("cache=none") cifs and smb2/smb3
do not go through the page cache and thus opens with O_DIRECT flag
should work (when posix extensions are negotiated we even are
able to send the flag to the server). This patch fixes that
in a simple way.

The 9P client has a similar situation (caching is often disabled)
and takes the same approach to O_DIRECT support ie works if caching
disabled, but if client caching enabled it fails with EINVAL.

A followon idea for a future patch as Pavel noted, could
be that files opened with O_DIRECT could cause us to change
inode->i_fop on the fly from

cifs_file_strict_ops

to

cifs_file_direct_ops

which would allow us to support this on non-forcedirectio mounts
(cache=strict and cache=loose) as well.

Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-11-11 16:42:37 -06:00
David Howells
54afa99057 CIFS: FS-Cache: Uncache unread pages in cifs_readpages() before freeing them
In cifs_readpages(), we may decide we don't want to read a page after all -
but the page may already have passed through fscache_read_or_alloc_pages() and
thus have marks and reservations set.  Thus we have to call
fscache_readpages_cancel() or fscache_uncache_page() on the pages we're
returning to clear the marks.

NFS, AFS and 9P should be unaffected by this as they call read_cache_pages()
which does the cleanup for you.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-18 10:17:03 -05:00
Sachin Prabhu
466bd31bbd cifs: Avoid calling unlock_page() twice in cifs_readpage() when using fscache
When reading a single page with cifs_readpage(), we make a call to
fscache_read_or_alloc_page() which once done, asynchronously calls
the completion function cifs_readpage_from_fscache_complete(). This
completion function unlocks the page once it has been populated from
cache. The module then attempts to unlock the page a second time in
cifs_readpage() which leads to warning messages.

In case of a successful call to fscache_read_or_alloc_page() we should skip
the second unlock_page() since this will be called by the
cifs_readpage_from_fscache_complete() once the page has been populated by
fscache.

With the modifications to cifs_readpage_worker(), we will need to re-grab the
page lock in cifs_write_begin().

The problem was first noticed when testing new fscache patches for cifs.
https://bugzilla.redhat.com/show_bug.cgi?id=1005737

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-13 16:24:49 -05:00
Sachin Prabhu
a9e9b7bc15 cifs: Do not take a reference to the page in cifs_readpage_worker()
We do not need to take a reference to the pagecache in
cifs_readpage_worker() since the calling function will have already
taken one before passing the pointer to the page as an argument to the
function.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-13 16:24:43 -05:00
Pavel Shilovsky
42873b0a28 CIFS: Respect epoch value from create lease context v2
that force a client to purge cache pages when a server requests it.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-09 22:52:18 -05:00
Pavel Shilovsky
53ef1016fd CIFS: Store lease state itself rather than a mapped oplock value
and separate smb20_operations struct.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-09 22:52:05 -05:00
Pavel Shilovsky
18cceb6a78 CIFS: Replace clientCanCache* bools with an integer
that prepare the code to handle different types of SMB2 leases.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08 17:49:17 -05:00
Christoph Hellwig
02afc27fae direct-io: Handle O_(D)SYNC AIO
Call generic_write_sync() from the deferred I/O completion handler if
O_DSYNC is set for a write request.  Also make sure various callers
don't call generic_write_sync if the direct I/O code returns
-EIOCBQUEUED.

Based on an earlier patch from Jan Kara <jack@suse.cz> with updates from
Jeff Moyer <jmoyer@redhat.com> and Darrick J. Wong <darrick.wong@oracle.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04 09:23:46 -04:00
Andi Shyti
fe090e4e44 cifs: file: initialize oparms.reconnect before using it
In the cifs_reopen_file function, if the following statement is
asserted:

(tcon->unix_ext && cap_unix(tcon->ses) &&
            (CIFS_UNIX_POSIX_PATH_OPS_CAP &
            (tcon->fsUnixInfo.Capability)))

and we succeed to open with cifs_posix_open, the function jumps
to the label reopen_success and checks for oparms.reconnect
which is not initialized.

This issue has been reported by scan.coverity.com

Signed-off-by: Andi Shyti <andi@etezian.org>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-07-30 23:54:49 -05:00
Pavel Shilovsky
689c3db4d5 CIFS: Fix a deadlock when a file is reopened
If we request reading or writing on a file that needs to be
reopened, it causes the deadlock: we are already holding rw
semaphore for reading and then we try to acquire it for writing
in cifs_relock_file. Fix this by acquiring the semaphore for
reading in cifs_relock_file due to we don't make any changes in
locks and don't need a write access.

CC: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-07-11 18:05:41 -05:00