linux-toradex.git/fs, branch v3.16.3

CIFS: Fix SMB2 readdir error handling

2014-09-17T16:22:22+00:00

commit 52755808d4525f4d5b86d112d36ffc7a46f3fb48 upstream.

SMB2 servers indicates the end of a directory search with
STATUS_NO_MORE_FILE error code that is not processed now.
This causes generic/257 xfstest to fail. Fix this by triggering
the end of search by this error code in SMB2_query_directory.

Also when negotiating CIFS protocol we tell the server to close
the search automatically at the end and there is no need to do
it itself. In the case of SMB2 protocol, we need to close it
explicitly - separate close directory checks for different
protocols.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

vfs: fix bad hashing of dentries

2014-09-17T16:22:22+00:00

commit 99d263d4c5b2f541dfacb5391e22e8c91ea982a6 upstream.

Josef Bacik found a performance regression between 3.2 and 3.10 and
narrowed it down to commit bfcfaa77bdf0 ("vfs: use 'unsigned long'
accesses for dcache name comparison and hashing"). He reports:

 "The test case is essentially

      for (i = 0; i < 1000000; i++)
              mkdir("a$i");

  On xfs on a fio card this goes at about 20k dir/sec with 3.2, and 12k
  dir/sec with 3.10.  This is because we spend waaaaay more time in
  __d_lookup on 3.10 than in 3.2.

  The new hashing function for strings is suboptimal for <
  sizeof(unsigned long) string names (and hell even > sizeof(unsigned
  long) string names that I've tested).  I broke out the old hashing
  function and the new one into a userspace helper to get real numbers
  and this is what I'm getting:

      Old hash table had 1000000 entries, 0 dupes, 0 max dupes
      New hash table had 12628 entries, 987372 dupes, 900 max dupes
      We had 11400 buckets with a p50 of 30 dupes, p90 of 240 dupes, p99 of 567 dupes for the new hash

  My test does the hash, and then does the d_hash into a integer pointer
  array the same size as the dentry hash table on my system, and then
  just increments the value at the address we got to see how many
  entries we overlap with.

  As you can see the old hash function ended up with all 1 million
  entries in their own bucket, whereas the new one they are only
  distributed among ~12.5k buckets, which is why we're using so much
  more CPU in __d_lookup".

The reason for this hash regression is two-fold:

 - On 64-bit architectures the down-mixing of the original 64-bit
   word-at-a-time hash into the final 32-bit hash value is very
   simplistic and suboptimal, and just adds the two 32-bit parts
   together.

   In particular, because there is no bit shuffling and the mixing
   boundary is also a byte boundary, similar character patterns in the
   low and high word easily end up just canceling each other out.

 - the old byte-at-a-time hash mixed each byte into the final hash as it
   hashed the path component name, resulting in the low bits of the hash
   generally being a good source of hash data.  That is not true for the
   word-at-a-time case, and the hash data is distributed among all the
   bits.

The fix is the same in both cases: do a better job of mixing the bits up
and using as much of the hash data as possible.  We already have the
"hash_32|64()" functions to do that.

Reported-by: Josef Bacik 
Cc: Al Viro 
Cc: Christoph Hellwig 
Cc: Chris Mason 
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix wrong restart readdir for SMB1

2014-09-17T16:22:20+00:00

commit f736906a7669a77cf8cabdcbcf1dc8cb694e12ef upstream.

The existing code calls server->ops->close() that is not
right. This causes XFS test generic/310 to fail. Fix this
by using server->ops->closedir() function.

Signed-off-by: Dan Carpenter 
Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix wrong filename length for SMB2

2014-09-17T16:22:20+00:00

commit 1bbe4997b13de903c421c1cc78440e544b5f9064 upstream.

The existing code uses the old MAX_NAME constant. This causes
XFS test generic/013 to fail. Fix it by replacing MAX_NAME with
PATH_MAX that SMB1 uses. Also remove an unused MAX_NAME constant
definition.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix directory rename error

2014-09-17T16:22:20+00:00

commit a07d322059db66b84c9eb4f98959df468e88b34b upstream.

CIFS servers process nlink counts differently for files and directories.
In cifs_rename() if we the request fails on the existing target, we
try to remove it through cifs_unlink() but this is not what we want
to do for directories. As the result the following sequence of commands

mkdir {1,2}; mv -T 1 2; rmdir {1,2}; mkdir {1,2}; echo foo > 2/bar

and XFS test generic/023 fail with -ENOENT error. That's why the second
mkdir reuses the existing inode (target inode of the mv -T command) with
S_DEAD flag.

Fix this by checking whether the target is directory or not and
calling cifs_rmdir() rather than cifs_unlink() for directories.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix wrong directory attributes after rename

2014-09-17T16:22:20+00:00

commit b46799a8f28c43c5264ac8d8ffa28b311b557e03 upstream.

When we requests rename we also need to update attributes
of both source and target parent directories. Not doing it
causes generic/309 xfstest to fail on SMB2 mounts. Fix this
by marking these directories for force revalidating.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

CIFS: Possible null ptr deref in SMB2_tcon

2014-09-17T16:22:19+00:00

commit 18f39e7be0121317550d03e267e3ebd4dbfbb3ce upstream.

As Raphael Geissert pointed out, tcon_error_exit can dereference tcon
and there is one path in which tcon can be null.

Signed-off-by: Steve French 
Reported-by: Raphael Geissert 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix async reading on reconnects

2014-09-17T16:22:19+00:00

commit 038bc961c31b070269ecd07349a7ee2e839d4fec upstream.

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 
Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

CIFS: Fix STATUS_CANNOT_DELETE error mapping for SMB2

2014-09-17T16:22:19+00:00

commit 21496687a79424572f46a84c690d331055f4866f upstream.

The existing mapping causes unlink() call to return error after delete
operation. Changing the mapping to -EACCES makes the client process
the call like CIFS protocol does - reset dos attributes with ATTR_READONLY
flag masked off and retry the operation.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

xfs: don't zero partial page cache pages during O_DIRECT writes

2014-09-17T16:22:18+00:00

commit 85e584da3212140ee80fd047f9058bbee0bc00d5 upstream.

xfs is using truncate_pagecache_range to invalidate the page cache
during DIO reads.  This is different from the other filesystems who
only invalidate pages during DIO writes.

truncate_pagecache_range is meant to be used when we are freeing the
underlying data structs from disk, so it will zero any partial
ranges in the page.  This means a DIO read can zero out part of the
page cache page, and it is possible the page will stay in cache.

buffered reads will find an up to date page with zeros instead of
the data actually on disk.

This patch fixes things by using invalidate_inode_pages2_range
instead.  It preserves the page cache invalidation, but won't zero
any pages.

[dchinner: catch error and warn if it fails. Comment.]

Signed-off-by: Chris Mason 
Reviewed-by: Dave Chinner 
Reviewed-by: Brian Foster 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Dave Chinner 
Signed-off-by: Greg Kroah-Hartman