The 9P2000 protocol requires the authentication and permission checks to be
done in the file server. For that reason every user that accesses the file
server tree has to authenticate and attach to the server separately.
Multiple users can share the same connection to the server.
Currently v9fs does a single attach and executes all I/O operations as a
single user. This makes using v9fs in multiuser environment unsafe as it
depends on the client doing the permission checking.
This patch improves the 9P2000 support by allowing every user to attach
separately. The patch defines three modes of access (new mount option
'access'):
- attach-per-user (access=user) (default mode for 9P2000.u)
If a user tries to access a file served by v9fs for the first time, v9fs
sends an attach command to the server (Tattach) specifying the user. If
the attach succeeds, the user can access the v9fs tree.
As there is no uname->uid (string->integer) mapping yet, this mode works
only with the 9P2000.u dialect.
- allow only one user to access the tree (access=<uid>)
Only the user with uid can access the v9fs tree. Other users that attempt
to access it will get EPERM error.
- do all operations as a single user (access=any) (default for 9P2000)
V9fs does a single attach and all operations are done as a single user.
If this mode is selected, the v9fs behavior is identical with the current
one.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This patch abstracts out the interfaces to underlying transports so that
new transports can be added as modules. This should also allow kernel
configuration of transports without ifdef-hell.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
When buf_check_overflow() returns != 0 we will hit kfree(ERR_PTR(err))
and it will not be happy about it.
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
On 7/22/07, Adrian Bunk <bunk@stusta.de> wrote:
The Coverity checker spotted the following use-after-free
in net/9p/mux.c:
<-- snip -->
...
struct p9_conn *p9_conn_create(struct p9_transport *trans, int msize,
unsigned char *extended)
{
...
if (!m->tagpool) {
kfree(m);
return ERR_PTR(PTR_ERR(m->tagpool));
}
...
<-- snip -->
Also spotted was a leak of the same structure further down in the function.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
When buf_check_overflow() returns != 0 we will hit kfree(ERR_PTR(err)) and
it will not be happy about it.
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The recent 9p commit: bd238fb431 that
supposedly only moved files also introduced a new 9p sysctl interface
that did not properly register it's sysctl binary numbers.
And since it was only for debugging clearly did not need a binary fast
path in any case. So this patch just remove the binary numbers.
See Documentation/sysctl/ctl_unnumbered.txt for more details.
While I was at it I cleaned up the sysctl initializers a little as
well so there is less to read.
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
umounting partitions after heavy activity would sometimes trigger a
segmentation violation. This fix appears to remove that problem.
Fix originally provided by Latchesar Ionkov.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
If trans->write returns 0, p9_write_work goes through the error path, but
sets the error code to zero.
This patch sets the error code to EREMOTEIO if trans->write returns zero
value.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
This patchset moves non-filesystem interfaces of v9fs from fs/9p to net/9p.
It moves the transport, packet marshalling and connection layers to net/9p
leaving only the VFS related files in fs/9p. This work is being done in
preparation for in-kernel 9p servers as well as alternate 9p clients (other
than VFS).
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
