Commit Graph

369 Commits

Author SHA1 Message Date
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
Pavel Shilovsky b33fcf1c9d CIFS: Reopen the file if reconnect durable handle failed
This is a follow-on patch for 8/8 patch from the durable handles
series. It fixes the problem when durable file handle timeout
expired on the server and reopen returns -ENOENT for such files.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-07-11 18:05:08 -05:00
Pavel Shilovsky 9cbc0b7339 CIFS: Reconnect durable handles for SMB2
On reconnects, we need to reopen file and then obtain all byte-range
locks held by the client. SMB2 protocol provides feature to make
this process atomic by reconnecting to the same file handle
with all it's byte-range locks. This patch adds this capability
for SMB2 shares.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>
2013-07-10 13:08:40 -05:00
Pavel Shilovsky 226730b4d8 CIFS: Introduce cifs_open_parms struct
and pass it to the open() call.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>
2013-07-10 13:08:40 -05:00
Linus Torvalds 790eac5640 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second set of VFS changes from Al Viro:
 "Assorted f_pos race fixes, making do_splice_direct() safe to call with
  i_mutex on parent, O_TMPFILE support, Jeff's locks.c series,
  ->d_hash/->d_compare calling conventions changes from Linus, misc
  stuff all over the place."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  Document ->tmpfile()
  ext4: ->tmpfile() support
  vfs: export lseek_execute() to modules
  lseek_execute() doesn't need an inode passed to it
  block_dev: switch to fixed_size_llseek()
  cpqphp_sysfs: switch to fixed_size_llseek()
  tile-srom: switch to fixed_size_llseek()
  proc_powerpc: switch to fixed_size_llseek()
  ubi/cdev: switch to fixed_size_llseek()
  pci/proc: switch to fixed_size_llseek()
  isapnp: switch to fixed_size_llseek()
  lpfc: switch to fixed_size_llseek()
  locks: give the blocked_hash its own spinlock
  locks: add a new "lm_owner_key" lock operation
  locks: turn the blocked_list into a hashtable
  locks: convert fl_link to a hlist_node
  locks: avoid taking global lock if possible when waking up blocked waiters
  locks: protect most of the file_lock handling with i_lock
  locks: encapsulate the fl_link list handling
  locks: make "added" in __posix_lock_file a bool
  ...
2013-07-03 09:10:19 -07:00
Jeff Layton 1c8c601a8c locks: protect most of the file_lock handling with i_lock
Having a global lock that protects all of this code is a clear
scalability problem. Instead of doing that, move most of the code to be
protected by the i_lock instead. The exceptions are the global lists
that the ->fl_link sits on, and the ->fl_block list.

->fl_link is what connects these structures to the
global lists, so we must ensure that we hold those locks when iterating
over or updating these lists.

Furthermore, sound deadlock detection requires that we hold the
blocked_list state steady while checking for loops. We also must ensure
that the search and update to the list are atomic.

For the checking and insertion side of the blocked_list, push the
acquisition of the global lock into __posix_lock_file and ensure that
checking and update of the  blocked_list is done without dropping the
lock in between.

On the removal side, when waking up blocked lock waiters, take the
global lock before walking the blocked list and dequeue the waiters from
the global list prior to removal from the fl_block list.

With this, deadlock detection should be race free while we minimize
excessive file_lock_lock thrashing.

Finally, in order to avoid a lock inversion problem when handling
/proc/locks output we must ensure that manipulations of the fl_block
list are also protected by the file_lock_lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:42 +04:00
Jeff Layton 1a9e64a711 cifs: use posix_unblock_lock instead of locks_delete_block
commit 66189be74 (CIFS: Fix VFS lock usage for oplocked files) exported
the locks_delete_block symbol. There's already an exported helper
function that provides this capability however, so make cifs use that
instead and turn locks_delete_block back into a static function.

Note that if fl->fl_next == NULL then this lock has already been through
locks_delete_block(), so we should be OK to ignore an ENOENT error here
and simply not retry the lock.

Cc: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:38 +04:00
Lukas Czerner d47992f86b mm: change invalidatepage prototype to accept length
Currently there is no way to truncate partial page where the end
truncate point is not at the end of the page. This is because it was not
needed and the functionality was enough for file system truncate
operation to work properly. However more file systems now support punch
hole feature and it can benefit from mm supporting truncating page just
up to the certain point.

Specifically, with this functionality truncate_inode_pages_range() can
be changed so it supports truncating partial page at the end of the
range (currently it will BUG_ON() if 'end' is not at the end of the
page).

This commit changes the invalidatepage() address space operation
prototype to accept range to be invalidated and update all the instances
for it.

We also change the block_invalidatepage() in the same way and actually
make a use of the new length argument implementing range invalidation.

Actual file system implementations will follow except the file systems
where the changes are really simple and should not change the behaviour
in any way .Implementation for truncate_page_range() which will be able
to accept page unaligned ranges will follow as well.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
2013-05-21 23:17:23 -04:00
Joe Perches f96637be08 [CIFS] cifs: Rename cERROR and cFYI to cifs_dbg
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>
2013-05-04 22:17:23 -05:00
Al Viro 8d71db4f08 lift sb_start_write/sb_end_write out of ->aio_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:12:55 -04:00
Mateusz Guzik 24261fc23d cifs: delay super block destruction until all cifsFileInfo objects are gone
cifsFileInfo objects hold references to dentries and it is possible that
these will still be around in workqueues when VFS decides to kill super
block during unmount.

This results in panics like this one:
BUG: Dentry ffff88001f5e76c0{i=66b4a,n=1M-2} still in use (1) [unmount of cifs cifs]
------------[ cut here ]------------
kernel BUG at fs/dcache.c:943!
[..]
Process umount (pid: 1781, threadinfo ffff88003d6e8000, task ffff880035eeaec0)
[..]
Call Trace:
 [<ffffffff811b44f3>] shrink_dcache_for_umount+0x33/0x60
 [<ffffffff8119f7fc>] generic_shutdown_super+0x2c/0xe0
 [<ffffffff8119f946>] kill_anon_super+0x16/0x30
 [<ffffffffa036623a>] cifs_kill_sb+0x1a/0x30 [cifs]
 [<ffffffff8119fcc7>] deactivate_locked_super+0x57/0x80
 [<ffffffff811a085e>] deactivate_super+0x4e/0x70
 [<ffffffff811bb417>] mntput_no_expire+0xd7/0x130
 [<ffffffff811bc30c>] sys_umount+0x9c/0x3c0
 [<ffffffff81657c19>] system_call_fastpath+0x16/0x1b

Fix this by making each cifsFileInfo object hold a reference to cifs
super block, which implicitly keeps VFS super block around as well.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-and-Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2013-03-13 14:12:06 -05:00
Steve French 07b92d0d57 POSIX extensions disabled on client due to illegal O_EXCL flag sent to Samba
Samba rejected libreoffice's attempt to open a file with illegal
O_EXCL (without O_CREAT).  Mask this flag off (as the local
linux file system case does) for this case, so that we
don't have disable Unix Extensions unnecessarily due to
the Samba error (Samba server is also being fixed).

See https://bugzilla.samba.org/show_bug.cgi?id=9519

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2013-02-27 16:54:18 -06:00
Linus Torvalds d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Linus Torvalds 94f2f14234 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace and namespace infrastructure changes from Eric W Biederman:
 "This set of changes starts with a few small enhnacements to the user
  namespace.  reboot support, allowing more arbitrary mappings, and
  support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the
  user namespace root.

  I do my best to document that if you care about limiting your
  unprivileged users that when you have the user namespace support
  enabled you will need to enable memory control groups.

  There is a minor bug fix to prevent overflowing the stack if someone
  creates way too many user namespaces.

  The bulk of the changes are a continuation of the kuid/kgid push down
  work through the filesystems.  These changes make using uids and gids
  typesafe which ensures that these filesystems are safe to use when
  multiple user namespaces are in use.  The filesystems converted for
  3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs.  The
  changes for these filesystems were a little more involved so I split
  the changes into smaller hopefully obviously correct changes.

  XFS is the only filesystem that remains.  I was hoping I could get
  that in this release so that user namespace support would be enabled
  with an allyesconfig or an allmodconfig but it looks like the xfs
  changes need another couple of days before it they are ready."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits)
  cifs: Enable building with user namespaces enabled.
  cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t
  cifs: Convert struct cifs_sb_info to use kuids and kgids
  cifs: Modify struct smb_vol to use kuids and kgids
  cifs: Convert struct cifsFileInfo to use a kuid
  cifs: Convert struct cifs_fattr to use kuid and kgids
  cifs: Convert struct tcon_link to use a kuid.
  cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
  cifs: Convert from a kuid before printing current_fsuid
  cifs: Use kuids and kgids SID to uid/gid mapping
  cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc
  cifs: Use BUILD_BUG_ON to validate uids and gids are the same size
  cifs: Override unmappable incoming uids and gids
  nfsd: Enable building with user namespaces enabled.
  nfsd: Properly compare and initialize kuids and kgids
  nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids
  nfsd: Modify nfsd4_cb_sec to use kuids and kgids
  nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
  nfsd: Convert nfsxdr to use kuids and kgids
  nfsd: Convert nfs3xdr to use kuids and kgids
  ...
2013-02-25 16:00:49 -08:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Eric W. Biederman fef59fd728 cifs: Convert struct cifsFileInfo to use a kuid
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-13 07:28:52 -08:00
Eric W. Biederman 49418b2c28 cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
Use INVALID_UID and INVALID_GID instead of NO_CHANGE_64 to indicate
the value should not be changed.

In cifs_fill_unix_set_info convert from kuids and kgids into uids and
gids that will fit in FILE_UNIX_BASIC_INFO.

Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-13 07:28:49 -08:00
Pavel Shilovsky 63b7d3a41c CIFS: Don't let read only caching for mandatory byte-range locked files
If we have mandatory byte-range locks on a file we can't cache reads
because pagereading may have conflicts with these locks on the server.
That's why we should allow level2 oplocks for files without mandatory
locks only.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-01-01 23:04:30 -06:00
Pavel Shilovsky 88cf75aaaf CIFS: Fix write after setting a read lock for read oplock files
If we have a read oplock and set a read lock in it, we can't write to the
locked area - so, filemap_fdatawrite may fail with a no information for a
userspace application even if we request a write to non-locked area. Fix
this by writing directly to the server and then breaking oplock level from
level2 to None.

Also remove CONFIG_CIFS_SMB2 ifdefs because it's suitable for both CIFS
and SMB2 protocols.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-01-01 23:04:14 -06:00
Pavel Shilovsky ca8aa29c60 Revert "CIFS: Fix write after setting a read lock for read oplock files"
that solution has data races and can end up two identical writes to the
server: when clientCanCacheAll value can be changed during the execution
of __generic_file_aio_write.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-01-01 22:59:55 -06:00
Pavel Shilovsky c299dd0e2d CIFS: Fix write after setting a read lock for read oplock files
If we have a read oplock and set a read lock in it, we can't write to the
locked area - so, filemap_fdatawrite may fail with a no information for a
userspace application even if we request a write to non-locked area. Fix
this by populating the page cache without marking affected pages dirty
after a successful write directly to the server.

Also remove CONFIG_CIFS_SMB2 ifdefs because it's suitable for both CIFS
and SMB2 protocols.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-12-11 11:48:50 -06:00
Pavel Shilovsky 03eca704cf CIFS: Fix possible data coherency problem after oplock break to None
by using cifs_invalidate_mapping rather than invalidate_remote_inode
in cifs_oplock_break - this invalidates all inode pages and resets
fscache cookies.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-12-07 13:08:07 -06:00
Pavel Shilovsky 081c0414dc CIFS: Do not permit write to a range mandatory locked with a read lock
We don't need to permit a write to the area locked with a read lock
by any process including the process that issues the write.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-12-07 12:40:50 -06:00