linux-stable.git/fs, branch v3.2.39

tcp: fix MSG_SENDPAGE_NOTLAST logic

2013-02-20T03:15:38+00:00

[ Upstream commit ae62ca7b03217be5e74759dc6d7698c95df498b3 ]

commit 35f9c09fe9c72e (tcp: tcp_sendpages() should call tcp_push() once)
added an internal flag : MSG_SENDPAGE_NOTLAST meant to be set on all
frags but the last one for a splice() call.

The condition used to set the flag in pipe_to_sendpage() relied on
splice() user passing the exact number of bytes present in the pipe,
or a smaller one.

But some programs pass an arbitrary high value, and the test fails.

The effect of this bug is a lack of tcp_push() at the end of a
splice(pipe -> socket) call, and possibly very slow or erratic TCP
sessions.

We should both test sd->total_len and fact that another fragment
is in the pipe (pipe->nrbufs > 1)

Many thanks to Willy for providing very clear bug report, bisection
and test programs.

Reported-by: Willy Tarreau 
Bisected-by: Willy Tarreau 
Tested-by: Willy Tarreau 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

nilfs2: fix fix very long mount time issue

2013-02-20T03:15:25+00:00

commit a9bae189542e71f91e61a4428adf6e5a7dfe8063 upstream.

There exists a situation when GC can work in background alone without
any other filesystem activity during significant time.

The nilfs_clean_segments() method calls nilfs_segctor_construct() that
updates superblocks in the case of NILFS_SC_SUPER_ROOT and
THE_NILFS_DISCONTINUED flags are set.  But when GC is working alone the
nilfs_clean_segments() is called with unset THE_NILFS_DISCONTINUED flag.
As a result, the update of superblocks doesn't occurred all this time
and in the case of SPOR superblocks keep very old values of last super
root placement.

SYMPTOMS:

Trying to mount a NILFS2 volume after SPOR in such environment ends with
very long mounting time (it can achieve about several hours in some
cases).

REPRODUCING PATH:

1. It needs to use external USB HDD, disable automount and doesn't
   make any additional filesystem activity on the NILFS2 volume.

2. Generate temporary file with size about 100 - 500 GB (for example,
   dd if=/dev/zero of= bs=1073741824 count=200).  The size of
   file defines duration of GC working.

3. Then it needs to delete file.

4. Start GC manually by means of command "nilfs-clean -p 0".  When you
   start GC by means of such way then, at the end, superblocks is updated
   by once.  So, for simulation of SPOR, it needs to wait sometime (15 -
   40 minutes) and simply switch off USB HDD manually.

5. Switch on USB HDD again and try to mount NILFS2 volume.  As a
   result, NILFS2 volume will mount during very long time.

REPRODUCIBILITY: 100%

FIX:

This patch adds checking that superblocks need to update and set
THE_NILFS_DISCONTINUED flag before nilfs_clean_segments() call.

Reported-by: Sergey Alexandrov 
Signed-off-by: Vyacheslav Dubeyko 
Tested-by: Vyacheslav Dubeyko 
Acked-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

NFSv4.1: Handle NFS4ERR_DELAY when resetting the NFSv4.1 session

2013-02-06T04:33:51+00:00

commit c489ee290bdbbace6bb63ebe6ebd4dd605819495 upstream.

NFS4ERR_DELAY is a legal reply when we call DESTROY_SESSION. It
usually means that the server is busy handling an unfinished RPC
request. Just sleep for a second and then retry.
We also need to be able to handle the NFS4ERR_BACK_CHAN_BUSY return
value. If the NFS server has outstanding callbacks, we just want to
similarly sleep & retry.

Signed-off-by: Trond Myklebust 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

NFS: Don't silently fail setattr() requests on mountpoints

2013-02-06T04:33:51+00:00

commit ab225417825963b6dc66be7ea80f94ac1378dfdf upstream.

Ensure that any setattr and getattr requests for junctions and/or
mountpoints are sent to the server. Ever since commit
0ec26fd0698 (vfs: automount should ignore LOOKUP_FOLLOW), we have
silently dropped any setattr requests to a server-side mountpoint.
For referrals, we have silently dropped both getattr and setattr
requests.

This patch restores the original behaviour for setattr on mountpoints,
and tries to do the same for referrals, provided that we have a
filehandle...

Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

xfs: Fix possible use-after-free with AIO

2013-02-06T04:33:49+00:00

commit 4b05d09c18d9aa62d2e7fb4b057f54e5a38963f5 upstream.

Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.

CC: xfs@oss.sgi.com
CC: Ben Myers 
Signed-off-by: Jan Kara 
Reviewed-by: Ben Myers 
Signed-off-by: Ben Myers 
Signed-off-by: Ben Hutchings

fs/cifs/cifs_dfs_ref.c: fix potential memory leakage

2013-02-06T04:33:42+00:00

commit 10b8c7dff5d3633b69e77f57d404dab54ead3787 upstream.

When it goes to error through line 144, the memory allocated to *devname is
not freed, and the caller doesn't free it either in line 250. So we free the
memroy of *devname in function cifs_compose_mount_options() when it goes to
error.

Signed-off-by: Cong Ding 
Reviewed-by: Jeff Layton 
Signed-off-by: Steve French 
Signed-off-by: Ben Hutchings

epoll: prevent missed events on EPOLL_CTL_MOD

2013-01-16T01:13:22+00:00

commit 128dd1759d96ad36c379240f8b9463e8acfd37a1 upstream.

EPOLL_CTL_MOD sets the interest mask before calling f_op->poll() to
ensure events are not missed.  Since the modifications to the interest
mask are not protected by the same lock as ep_poll_callback, we need to
ensure the change is visible to other CPUs calling ep_poll_callback.

We also need to ensure f_op->poll() has an up-to-date view of past
events which occured before we modified the interest mask.  So this
barrier also pairs with the barrier in wq_has_sleeper().

This should guarantee either ep_poll_callback or f_op->poll() (or both)
will notice the readiness of a recently-ready/modified item.

This issue was encountered by Andreas Voellmy and Junchang(Jason) Wang in:
http://thread.gmane.org/gmane.linux.kernel/1408782/

Signed-off-by: Eric Wong 
Cc: Hans Verkuil 
Cc: Jiri Olsa 
Cc: Jonathan Corbet 
Cc: Al Viro 
Cc: Davide Libenzi 
Cc: Hans de Goede 
Cc: Mauro Carvalho Chehab 
Cc: David Miller 
Cc: Eric Dumazet 
Cc: Andrew Morton 
Cc: Andreas Voellmy 
Tested-by: "Junchang(Jason) Wang" 
Cc: netdev@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

udf: don't increment lenExtents while writing to a hole

2013-01-16T01:13:21+00:00

commit fb719c59bdb4fca86ee1fd1f42ab3735ca12b6b2 upstream.

Incrementing lenExtents even while writing to a hole is bad
for performance as calls to udf_discard_prealloc and
udf_truncate_tail_extent would not return from start if
isize != lenExtents

Signed-off-by: Namjae Jeon 
Signed-off-by: Ashish Sangwan 
Signed-off-by: Jan Kara 
Signed-off-by: Ben Hutchings

nfs: fix null checking in nfs_get_option_str()

2013-01-16T01:13:19+00:00

commit e25fbe380c4e3c09afa98bcdcd9d3921443adab8 upstream.

The following null pointer check is broken.

	*option = match_strdup(args);
	return !option;

The pointer `option' must be non-null, and thus `!option' is always false.
Use `!*option' instead.

The bug was introduced in commit c5cb09b6f8 ("Cleanup: Factor out some
cut-and-paste code.").

Signed-off-by: Xi Wang 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

cifs: adjust sequence number downward after signing NT_CANCEL request

2013-01-16T01:13:13+00:00

commit 31efee60f489c759c341454d755a9fd13de8c03d upstream.

When a call goes out, the signing code adjusts the sequence number
upward by two to account for the request and the response. An NT_CANCEL
however doesn't get a response of its own, it just hurries the server
along to get it to respond to the original request more quickly.
Therefore, we must adjust the sequence number back down by one after
signing a NT_CANCEL request.

Reported-by: Tim Perry 
Signed-off-by: Jeff Layton 
Signed-off-by: Steve French 
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings