linux.git/net/9p/client.c, branch v3.12

Merge tag 'for-linus-3.12-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

2013-09-11T19:34:13+00:00

Pull 9p updates from Eric Van Hensbergen:
 "Minor 9p fixes and tweaks for 3.12 merge window

  The first fixes namespace issues which causes a kernel NULL pointer
  dereference, the second fixes uevent handling to work better with
  udev, and the third switches some code to use srlcpy instead of
  strncpy in order to be safer.

  All changes have been baking in for-next for at least 2 weeks"

* tag 'for-linus-3.12-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  fs/9p: avoid accessing utsname after namespace has been torn down
  9p: send uevent after adding/removing mount_tag attribute
  fs: 9p: use strlcpy instead of strncpy

fs/9p: avoid accessing utsname after namespace has been torn down

2013-08-26T15:28:46+00:00

During trinity fuzzing in a kvmtool guest, I stumbled across the
following:

Unable to handle kernel NULL pointer dereference at virtual address 00000004
PC is at v9fs_file_do_lock+0xc8/0x1a0
LR is at v9fs_file_do_lock+0x48/0x1a0
[] (v9fs_file_do_lock+0xc8/0x1a0) from [] (locks_remove_flock+0x8c/0x124)
[] (locks_remove_flock+0x8c/0x124) from [] (__fput+0x58/0x1e4)
[] (__fput+0x58/0x1e4) from [] (task_work_run+0xac/0xe8)
[] (task_work_run+0xac/0xe8) from [] (do_exit+0x6bc/0x8d8)
[] (do_exit+0x6bc/0x8d8) from [] (do_group_exit+0x3c/0xb0)
[] (do_group_exit+0x3c/0xb0) from [] (__wake_up_parent+0x0/0x18)

I believe this is due to an attempt to access utsname()->nodename, after
exit_task_namespaces() has been called, leaving current->nsproxy->uts_ns
as NULL and causing the above dereference.

A similar issue was fixed for lockd in 9a1b6bf818e7 ("LOCKD: Don't call
utsname()->nodename from nlmclnt_setlockargs"), so this patch attempts
something similar for 9pfs.

Cc: Eric Van Hensbergen 
Cc: Ron Minnich 
Cc: Latchesar Ionkov 
Cc: Trond Myklebust 
Signed-off-by: Will Deacon 
Signed-off-by: Eric Van Hensbergen

9p: client: remove unused code and any reference to "cancelled" function

2013-07-30T22:54:28+00:00

This patch reverts commit

80b45261a0b263536b043c5ccfc4ba4fc27c2acc

which was implementing a 'cancelled' functionality to notify that
a cancelled request will not be replied.

This implementation was not used anywhere and therefore removed.

Signed-off-by: Andi Shyti 
Signed-off-by: David S. Miller

9P: Add cancelled() to the transport functions.

2013-07-08T03:18:18+00:00

RDMA needs to post a buffer for each incoming reply.
Hence it needs to keep count of these and needs to be
aware of whether a flushed request has received a reply
or not.

This patch adds the cancelled() callback to the transport modules.
It is called when RFLUSH has been received and that the corresponding
request will never receive a reply.

Signed-off-by: Simon Derr 
Signed-off-by: Eric Van Hensbergen

9P/RDMA: count posted buffers without a pending request

2013-07-08T03:04:36+00:00

In rdma_request():

If an error occurs between posting the recv and the send,
there will be a reply context posted without a pending
request.
Since there is no way to "un-post" it, we remember it and
skip post_recv() for the next request.

Signed-off-by: Simon Derr 
Signed-off-by: Eric Van Hensbergen

9pnet: refactor struct p9_fcall alloc code

2013-07-08T03:02:27+00:00

Signed-off-by: Simon Derr 
Signed-off-by: Eric Van Hensbergen

9P: Fix fcall allocation for rdma

2013-07-08T03:02:26+00:00

The current code assumes that when a request in the request array
does have a tc, it also has a rc.

This is normally true, but not always : when using RDMA, req->rc
will temporarily be set to NULL after the request has been sent.
That is usually OK though, as when the reply arrives, req->rc will be
reassigned to a sane value before the request is recycled.

But there is a catch : if the request is flushed, the reply will never
arrive, and req->rc will be NULL, but not req->tc.

This patch fixes p9_tag_alloc to take this into account.

Signed-off-by: Simon Derr 
Signed-off-by: Eric Van Hensbergen

net/9p: Handle error in zero copy request correctly for 9p2000.u

2013-05-28T14:28:42+00:00

For zero copy request, error will be encoded in the user space buffer.
So copy the error code correctly using copy_from_user. Here we use the
extra bytes we allocate for zero copy request. If total error details
are more than P9_ZC_HDR_SZ - 7 bytes, we return -EFAULT. The patch also
avoid a memory allocation in the error path.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Eric Van Hensbergen

net/9p: Use virtio transpart as the default transport

2013-05-28T14:28:42+00:00

Make the default 9p experience better by defaulting to virtio transport if present.
These days most of the users are using 9p in a virtualized setup

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Eric Van Hensbergen

net/9p: Make 9P2000.L the default protocol for 9p file system

2013-05-28T14:28:42+00:00

If we dont' specify a protocol version default to 9P2000.L. 9P2000.L
have better support for posix semantic and is where all the recent development
is happening.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Eric Van Hensbergen