kernel/git/stable/linux.git/net/9p/client.c, branch linux-5.18.y

net/9p: Initialize the iounit field during fid creation

2022-08-17T12:42:24+00:00

[ Upstream commit aa7aeee169480e98cf41d83c01290a37e569be6d ] Ensure that the fid's iounit field is set to zero when a new fid is created. Certain 9P operations, such as OPEN and CREATE, allow the server to reply with an iounit size which the client code assigns to the p9_fid struct shortly after the fid is created by p9_fid_create(). On the other hand, an XATTRWALK operation doesn't allow for the server to specify an iounit value. The iounit field of the newly allocated p9_fid struct remained uninitialized in that case. Depending on allocation patterns, the iounit value could have been something reasonable that was carried over from previously freed fids or, in the worst case, could have been arbitrary values from non-fid related usages of the memory location. The bug was detected in the Windows Subsystem for Linux 2 (WSL2) kernel after the uninitialized iounit field resulted in the typical sequence of two getxattr(2) syscalls, one to get the size of an xattr and another after allocating a sufficiently sized buffer to fit the xattr value, to hit an unexpected ERANGE error in the second call to getxattr(2). An uninitialized iounit field would sometimes force rsize to be smaller than the xattr value size in p9_client_read_once() and the 9P server in WSL refused to chunk up the READ on the attr_fid and, instead, returned ERANGE to the client. The virtfs server in QEMU seems happy to chunk up the READ and this problem goes undetected there. Link: https://lkml.kernel.org/r/20220710141402.803295-1-tyhicks@linux.microsoft.com Fixes: ebf46264a004 ("fs/9p: Add support user. xattr") Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks Reviewed-by: Christian Schoenebeck Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

9p: Add client parameter to p9_req_put()

2022-08-17T12:42:06+00:00

[ Upstream commit 8b11ff098af42b1fa57fc817daadd53c8b244a0c ] This is to aid in adding mempools, in the next patch. Link: https://lkml.kernel.org/r/20220704014243.153050-2-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet Cc: Eric Van Hensbergen Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

9p: Drop kref usage

2022-08-17T12:42:06+00:00

[ Upstream commit 6cda12864cb0f99810a5809e11e3ee5b102c9a47 ] An upcoming patch is going to require passing the client through p9_req_put() -> p9_req_free(), but that's awkward with the kref indirection - so this patch switches to using refcount_t directly. Link: https://lkml.kernel.org/r/20220704014243.153050-1-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet Cc: Eric Van Hensbergen Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

net/9p: show error message if user 'msize' cannot be satisfied

2022-01-10T01:00:09+00:00

If user supplied a large value with the 'msize' option, then client would silently limit that 'msize' value to the maximum value supported by transport. That's a bit confusing for users of not having any indication why the preferred 'msize' value could not be satisfied. Link: https://lkml.kernel.org/r/783ba37c1566dd715b9a67d437efa3b77e3cd1a7.1640870037.git.linux_oss@crudebyte.com Reported-by: Vivek Goyal Signed-off-by: Christian Schoenebeck Signed-off-by: Dominique Martinet

9p: fix a bunch of checkpatch warnings

2021-11-04T12:04:25+00:00

Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but seemingly stopped halfway -- take over and do most of it. This is still missing net/9p/trans* and net/9p/protocol.c for a later time... Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet

9p: fix file headers

2021-11-03T08:45:04+00:00

- add missing SPDX-License-Identifier - remove (sometimes incorrect) file name from file header Link: http://lkml.kernel.org/r/20211102134608.1588018-2-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet

9p/net: fix missing error check in p9_check_errors

2021-11-03T00:49:54+00:00

Link: https://lkml.kernel.org/r/99338965-d36c-886e-cd0e-1d8fff2b4746@gmail.com Reported-by: syzbot+06472778c97ed94af66d@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet

net/9p: increase default msize to 128k

2021-09-04T23:36:44+00:00

Let's raise the default msize value to 128k. The 'msize' option defines the maximum message size allowed for any message being transmitted (in both directions) between 9p server and 9p client during a 9p session. Currently the default 'msize' is just 8k, which is way too conservative. Such a small 'msize' value has quite a negative performance impact, because individual 9p messages have to be split up far too often into numerous smaller messages to fit into this message size limitation. A default value of just 8k also has a much higher probablity of hitting short-read issues like: https://gitlab.com/qemu-project/qemu/-/issues/409 Unfortunately user feedback showed that many 9p users are not aware that this option even exists, nor the negative impact it might have if it is too low. Link: http://lkml.kernel.org/r/61ea0f0faaaaf26dd3c762eabe4420306ced21b9.1630770829.git.linux_oss@crudebyte.com Link: https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg01003.html Signed-off-by: Christian Schoenebeck Signed-off-by: Dominique Martinet

net/9p: use macro to define default msize

2021-09-04T23:36:44+00:00

Use a macro to define the default value for the 'msize' option at one place instead of using two separate integer literals. Link: http://lkml.kernel.org/r/28bb651ae0349a7d57e8ddc92c1bd5e62924a912.1630770829.git.linux_oss@crudebyte.com Signed-off-by: Christian Schoenebeck Signed-off-by: Dominique Martinet

net: 9p: Correct function names in the kerneldoc comments

2021-03-29T00:56:56+00:00

Fix the following W=1 kernel build warning(s): net/9p/client.c:133: warning: expecting prototype for parse_options(). Prototype was for parse_opts() instead net/9p/client.c:269: warning: expecting prototype for p9_req_alloc(). Prototype was for p9_tag_alloc() instead Reported-by: Hulk Robot Signed-off-by: Xiongfeng Wang Signed-off-by: David S. Miller