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327 commits

Author SHA1 Message Date
Peter Maydell
c7f1cf01b8 This pull request fixes a 2.9 regression and a long standing bug that can
cause 9p clients to hang. Other patches are minor enhancements.
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Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

This pull request fixes a 2.9 regression and a long standing bug that can
cause 9p clients to hang. Other patches are minor enhancements.

# gpg: Signature made Wed 25 Jan 2017 10:12:27 GMT
# gpg:                using DSA key 0x02FC3AEB0101DBC2
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg:                 aka "Greg Kurz <groug@free.fr>"
# gpg:                 aka "Greg Kurz <gkurz@fr.ibm.com>"
# gpg:                 aka "Greg Kurz <gkurz@linux.vnet.ibm.com>"
# gpg:                 aka "Gregory Kurz (Groug) <groug@free.fr>"
# gpg:                 aka "Gregory Kurz (Cimai Technology) <gkurz@cimai.com>"
# gpg:                 aka "Gregory Kurz (Meiosys Technology) <gkurz@meiosys.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 2BD4 3B44 535E C0A7 9894  DBA2 02FC 3AEB 0101 DBC2

* remotes/gkurz/tags/for-upstream:
  9pfs: fix offset error in v9fs_xattr_read()
  9pfs: local: trivial cosmetic fix in pwritev op
  9pfs: fix off-by-one error in PDU free list
  tests: virtio-9p: improve error reporting
  9pfs: add missing coroutine_fn annotations

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-01-25 17:54:14 +00:00
Greg Kurz
fa0eb5c512 9pfs: fix offset error in v9fs_xattr_read()
The current code tries to copy `read_count' bytes starting at offset
`offset' from a `read_count`-sized iovec. This causes v9fs_pack() to
fail with ENOBUFS.

Since the PDU iovec is already partially filled with `offset' bytes,
let's skip them when creating `qiov_full' and have v9fs_pack() to
copy the whole of it. Moreover, this is consistent with the other
places where v9fs_init_qiov_from_pdu() is called.

This fixes commit "bcb8998fac16 9pfs: call v9fs_init_qiov_from_pdu
before v9fs_pack".

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-01-25 09:34:35 +01:00
Greg Kurz
6fe76acc2d 9pfs: local: trivial cosmetic fix in pwritev op
Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-25 09:34:35 +01:00
Greg Kurz
0d78289c3d 9pfs: fix off-by-one error in PDU free list
The server can handle MAX_REQ - 1 PDUs at a time and the virtio-9p
device has a MAX_REQ sized virtqueue. If the client manages to fill
up the virtqueue, pdu_alloc() will fail and the request won't be
processed without any notice to the client (it actually causes the
linux 9p client to hang).

This has been there since the beginning (commit 9f10751365 "virtio-9p:
Add a virtio 9p device to qemu"), but it needs an agressive workload to
run in the guest to show up.

We actually allocate MAX_REQ PDUs and I see no reason not to link them
all into the free list, so let's fix the init loop.

Reported-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-25 09:34:35 +01:00
Greg Kurz
a1bf8b7414 9pfs: add missing coroutine_fn annotations
Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-25 09:34:35 +01:00
Ashijeet Acharya
fe44dc9180 migration: disallow migrate_add_blocker during migration
If a migration is already in progress and somebody attempts
to add a migration blocker, this should rightly fail.

Add an errp parameter and a retcode return value to migrate_add_blocker.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Ashijeet Acharya <ashijeetacharya@gmail.com>
Message-Id: <1484566314-3987-5-git-send-email-ashijeetacharya@gmail.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  Merged with recent 'Allow invtsc migration' change
2017-01-24 18:00:30 +00:00
Greg Kurz
baecbde6d7 9pfs: fix P9_NOTAG and P9_NOFID macros
The u16 and u32 types don't exist in QEMU common headers. It never broke
build because these two macros aren't use by the current code, but this
is about to change with the future addition of functional tests for 9P.

Also, these should have enclosing parenthesis to be usable in any
syntactical situation.

As suggested by Eric Blake, let's use UINT16_MAX and UINT32_MAX to address
both issues.

Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-03 17:28:44 +01:00
Greg Kurz
f2b58c4375 9pfs: fix crash when fsdev is missing
If the user passes -device virtio-9p without the corresponding -fsdev, QEMU
dereferences a NULL pointer and crashes.

This is a 2.8 regression introduced by commit 702dbcc274.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
2017-01-03 17:28:44 +01:00
Stefano Stabellini
88da0b0301 9pfs: introduce init_out/in_iov_from_pdu
Not all 9pfs transports share memory between request and response. For
those who don't, it is necessary to know how much memory is required in
the response.

Split the existing init_iov_from_pdu function in two:
init_out_iov_from_pdu (for writes) and init_in_iov_from_pdu (for reads).
init_in_iov_from_pdu takes an additional size parameter to specify the
memory required for the response message.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-03 17:28:44 +01:00
Stefano Stabellini
bcb8998fac 9pfs: call v9fs_init_qiov_from_pdu before v9fs_pack
v9fs_xattr_read should not access VirtQueueElement elems directly.
Move v9fs_init_qiov_from_pdu up in the file and call
v9fs_init_qiov_from_pdu before v9fs_pack. Use v9fs_pack on the new
iovec.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-03 17:28:44 +01:00
Stefano Stabellini
ea83441cc4 9pfs: introduce transport specific callbacks
Don't call virtio functions from 9pfs generic code, use generic function
callbacks instead.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-03 17:28:44 +01:00
Stefano Stabellini
583f21f8b9 9pfs: move pdus to V9fsState
pdus are initialized and used in 9pfs common code. Move the array from
V9fsVirtioState to V9fsState.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2017-01-03 17:28:44 +01:00
Li Qiang
898ae90a44 9pfs: add cleanup operation for proxy backend driver
In the init operation of proxy backend dirver, it allocates a
V9fsProxy struct and some other resources. We should free these
resources when the 9pfs device is unrealized. This is what this
patch does.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-23 13:53:34 +01:00
Li Qiang
971f406b77 9pfs: add cleanup operation for handle backend driver
In the init operation of handle backend dirver, it allocates a
handle_data struct and opens a mount file. We should free these
resources when the 9pfs device is unrealized. This is what this
patch does.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-23 13:53:34 +01:00
Li Qiang
702dbcc274 9pfs: add cleanup operation in FileOperations
Currently, the backend of VirtFS doesn't have a cleanup
function. This will lead resource leak issues if the backed
driver allocates resources. This patch addresses this issue.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-23 13:53:34 +01:00
Li Qiang
4774718e5c 9pfs: adjust the order of resource cleanup in device unrealize
Unrealize should undo things that were set during realize in
reverse order. So should do in the error path in realize.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-23 13:53:34 +01:00
Greg Kurz
79decce35b 9pfs: drop excessive error message from virtfs_reset()
The virtfs_reset() function is called either when the virtio-9p device
gets reset, or when the client starts a new 9P session. In both cases,
if it finds fids from a previous session, the following is printed in
the monitor:

9pfs:virtfs_reset: One or more uncluncked fids found during reset

For example, if a linux guest with a mounted 9P share is reset from the
monitor with system_reset, the message will be printed. This is excessive
since these fids are now clunked and the state is clean.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-11-01 12:03:03 +01:00
Greg Kurz
49dd946bb5 9pfs: don't BUG_ON() if fid is already opened
A buggy or malicious guest could pass the id of an already opened fid and
cause QEMU to abort. Let's return EINVAL to the guest instead.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-11-01 12:03:02 +01:00
Greg Kurz
dd654e0365 9pfs: xattrcreate requires non-opened fids
The xattrcreate operation only makes sense on a freshly cloned fid
actually, since any open state would be leaked because of the fid_type
change. This is indeed what the linux kernel client does:

	fid = clone_fid(fid);
	[...]
	retval = p9_client_xattrcreate(fid, name, value_len, flags);

This patch also reverts commit ff55e94d23 since we are sure that a fid
with type P9_FID_NONE doesn't have a previously allocated xattr.

Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-01 12:03:02 +01:00
Greg Kurz
3b79ef2cf4 9pfs: limit xattr size in xattrcreate
We shouldn't allow guests to create extended attribute with arbitrary sizes.
On linux hosts, the limit is XATTR_SIZE_MAX. Let's use it.

Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-01 12:03:02 +01:00
Li Qiang
7e55d65c56 9pfs: fix integer overflow issue in xattr read/write
The v9fs_xattr_read() and v9fs_xattr_write() are passed a guest
originated offset: they must ensure this offset does not go beyond
the size of the extended attribute that was set in v9fs_xattrcreate().
Unfortunately, the current code implement these checks with unsafe
calculations on 32 and 64 bit values, which may allow a malicious
guest to cause OOB access anyway.

Fix this by comparing the offset and the xattr size, which are
both uint64_t, before trying to compute the effective number of bytes
to read or write.

Suggested-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-By: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-01 12:03:01 +01:00
Li Qiang
8495f9ad26 9pfs: convert 'len/copied_len' field in V9fsXattr to the type of uint64_t
The 'len' in V9fsXattr comes from the 'size' argument in setxattr()
function in guest. The setxattr() function's declaration is this:

int setxattr(const char *path, const char *name,
             const void *value, size_t size, int flags);

and 'size' is treated as u64 in linux kernel client code:

int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
                          u64 attr_size, int flags)

So the 'len' should have an type of 'uint64_t'.
The 'copied_len' in V9fsXattr is used to account for copied bytes, it
should also have an type of 'uint64_t'.

Suggested-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-01 12:03:01 +01:00
Li Qiang
dd28fbbc2e 9pfs: add xattrwalk_fid field in V9fsXattr struct
Currently, 9pfs sets the 'copied_len' field in V9fsXattr
to -1 to tag xattr walk fid. As the 'copied_len' is also
used to account for copied bytes, this may make confusion. This patch
add a bool 'xattrwalk_fid' to tag the xattr walk fid.

Suggested-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-11-01 12:00:40 +01:00
Li Qiang
fdfcc9aeea 9pfs: fix memory leak in v9fs_write
If an error occurs when marshalling the transfer length to the guest, the
v9fs_write() function doesn't free an IO vector, thus leading to a memory
leak. This patch fixes the issue.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Greg Kurz <groug@kaod.org>
[groug, rephrased the changelog]
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Li Qiang
4c1586787f 9pfs: fix memory leak in v9fs_link
The v9fs_link() function keeps a reference on the source fid object. This
causes a memory leak since the reference never goes down to 0. This patch
fixes the issue.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Greg Kurz <groug@kaod.org>
[groug, rephrased the changelog]
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Li Qiang
ff55e94d23 9pfs: fix memory leak in v9fs_xattrcreate
The 'fs.xattr.value' field in V9fsFidState object doesn't consider the
situation that this field has been allocated previously. Every time, it
will be allocated directly. This leads to a host memory leak issue if
the client sends another Txattrcreate message with the same fid number
before the fid from the previous time got clunked.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Greg Kurz <groug@kaod.org>
[groug, updated the changelog to indicate how the leak can occur]
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Li Qiang
eb68760285 9pfs: fix information leak in xattr read
9pfs uses g_malloc() to allocate the xattr memory space, if the guest
reads this memory before writing to it, this will leak host heap memory
to the guest. This patch avoid this.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Greg Kurz
0e44a0fd3f virtio-9p: add reset handler
Virtio devices should implement the VirtIODevice->reset() function to
perform necessary cleanup actions and to bring the device to a quiescent
state.

In the case of the virtio-9p device, this means:
- emptying the list of active PDUs (i.e. draining all in-flight I/O)
- freeing all fids (i.e. close open file descriptors and free memory)

That's what this patch does.

The reset handler first waits for all active PDUs to complete. Since
completion happens in the QEMU global aio context, we just have to
loop around aio_poll() until the active list is empty.

The freeing part involves some actions to be performed on the backend,
like closing file descriptors or flushing extended attributes to the
underlying filesystem. The virtfs_reset() function already does the
job: it calls free_fid() for all open fids not involved in an ongoing
I/O operation. We are sure this is the case since we have drained
the PDU active list.

The current code implements all backend accesses with coroutines, but we
want to stay synchronous on the reset path. We can either change the
current code to be able to run when not in coroutine context, or create
a coroutine context and wait for virtfs_reset() to complete. This patch
goes for the latter because it results in simpler code.

Note that we also need to create a dummy PDU because it is also an API
to pass the FsContext pointer to all backend callbacks.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-17 14:13:58 +02:00
Greg Kurz
f74e27bf0f 9pfs: only free completed request if not flushed
If a PDU has a flush request pending, the current code calls pdu_free()
twice:

1) pdu_complete()->pdu_free() with pdu->cancelled set, which does nothing

2) v9fs_flush()->pdu_free() with pdu->cancelled cleared, which moves the
   PDU back to the free list.

This works but it complexifies the logic of pdu_free().

With this patch, pdu_complete() only calls pdu_free() if no flush request
is pending, i.e. qemu_co_queue_next() returns false.

Since pdu_free() is now supposed to be called with pdu->cancelled cleared,
the check in pdu_free() is dropped and replaced by an assertion.

Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Greg Kurz
6868a420c5 9pfs: drop useless check in pdu_free()
Out of the three users of pdu_free(), none ever passes a NULL pointer to
this function.

Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Greg Kurz
8440e22ec1 9pfs: use coroutine_fn annotation in hw/9pfs/9p.[ch]
All these functions either call the v9fs_co_* functions which have the
coroutine_fn annotation, or pdu_complete() which calls qemu_co_queue_next().

Let's mark them to make it obvious they execute in coroutine context.

Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Greg Kurz
5bdade6621 9pfs: use coroutine_fn annotation in hw/9pfs/co*.[ch]
All these functions use the v9fs_co_run_in_worker() macro, and thus always
call qemu_coroutine_self() and qemu_coroutine_yield().

Let's mark them to make it obvious they execute in coroutine context.

Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Greg Kurz
bc70a5925f 9pfs: fsdev: drop useless extern annotation for functions
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Li Qiang
e95c9a493a 9pfs: fix potential host memory leak in v9fs_read
In 9pfs read dispatch function, it doesn't free two QEMUIOVector
object thus causing potential memory leak. This patch avoid this.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Li Qiang
ba42ebb863 9pfs: allocate space for guest originated empty strings
If a guest sends an empty string paramater to any 9P operation, the current
code unmarshals it into a V9fsString equal to { .size = 0, .data = NULL }.

This is unfortunate because it can cause NULL pointer dereference to happen
at various locations in the 9pfs code. And we don't want to check str->data
everywhere we pass it to strcmp() or any other function which expects a
dereferenceable pointer.

This patch enforces the allocation of genuine C empty strings instead, so
callers don't have to bother.

Out of all v9fs_iov_vunmarshal() users, only v9fs_xattrwalk() checks if
the returned string is empty. It now uses v9fs_string_size() since
name.data cannot be NULL anymore.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
[groug, rewritten title and changelog,
 fix empty string check in v9fs_xattrwalk()]
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-10-17 14:13:58 +02:00
Halil Pasic
5705653ff8 virtio: cleanup VMSTATE_VIRTIO_DEVICE
Now all the usages of the old version of VMSTATE_VIRTIO_DEVICE are gone,
so we can get rid of the conditionals, and the old macro.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 02:21:43 +03:00
Halil Pasic
dcaf8dda4b virtio-9p: convert VMSTATE_VIRTIO_DEVICE
Use the new VMSTATE_VIRTIO_DEVICE macro.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 02:21:42 +03:00
Greg Kurz
d3d74d6fe0 virtio-9p: handle handle_9p_output() error
A broken guest may send a request without providing buffers for the reply
or for the request itself, and virtqueue_pop() will return an element with
either in_num == 0 or out_num == 0.

All 9P requests are expected to start with the following 7-byte header:

            uint32_t size_le;
            uint8_t id;
            uint16_t tag_le;

If iov_to_buf() fails to return these 7 bytes, then something is wrong in
the guest.

In both cases, it is wrong to crash QEMU, since the root cause lies in the
guest.

This patch hence does the following:
- keep the check of in_num since pdu_complete() assumes it has enough
  space to store the reply and we will send something broken to the guest
- let iov_to_buf() handle out_num == 0, since it will return 0 just like
  if the guest had provided an zero-sized buffer.
- call virtio_error() to inform the guest that the device is now broken,
  instead of aborting
- detach the request from the virtqueue and free it

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 01:16:59 +03:00
Greg Kurz
e8582891cb virtio-9p: add parentheses to sizeof operator
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 01:16:58 +03:00
Greg Kurz
13fd08e631 9pfs: fix potential segfault during walk
If the call to fid_to_qid() returns an error, we will call v9fs_path_free()
on uninitialized paths.

It is a regression introduced by the following commit:

56f101ecce 9pfs: handle walk of ".." in the root directory

Let's fix this by initializing dpath and path before calling fid_to_qid().

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[groug: updated the changelog to indicate this is regression and to provide
        the offending commit SHA1]
Signed-off-by: Greg Kurz <groug@kaod.org>
2016-09-19 11:39:48 +02:00
Greg Kurz
e3e83f2e21 9pfs: introduce v9fs_path_sprintf() helper
This helper is similar to v9fs_string_sprintf(), but it includes the
terminating NUL character in the size field.

This is to avoid doing v9fs_string_sprintf((V9fsString *) &path) and
then bumping the size.

Affected users are changed to use this new helper.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
2016-09-16 08:56:15 +02:00
Greg Kurz
abdf008640 9pfs: drop useless v9fs_string_null() function
The v9fs_string_null() function just calls v9fs_string_free(). Also it
only has 4 users, whereas v9fs_string_free() has 87.

This patch converts users to call directly v9fs_string_free() and drops
the useless function.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
2016-09-16 08:56:15 +02:00
Greg Kurz
da4bc86c54 9pfs: drop duplicate line in proxy backend
This double free did not cause harm because v9fs_string_free() sets
str->data to NULL and g_free(NULL) is valid.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
2016-09-16 08:56:14 +02:00
Greg Kurz
799fe087e4 9pfs: drop unused fmt strings in the proxy backend
The v9fs_request() function doesn't use its fmt argument: it passes literal
format strings to proxy_marshal() for all commands.

This patch simply drops the unused fmt argument and updates all callers
accordingly.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
2016-09-16 08:56:14 +02:00
Greg Kurz
56f101ecce 9pfs: handle walk of ".." in the root directory
The 9P spec at http://man.cat-v.org/plan_9/5/intro says:

All directories must support walks to the directory .. (dot-dot) meaning
parent directory, although by convention directories contain no explicit
entry for .. or . (dot).  The parent of the root directory of a server's
tree is itself.

This means that a client cannot walk further than the root directory
exported by the server. In other words, if the client wants to walk
"/.." or "/foo/../..", the server should answer like the request was
to walk "/".

This patch just does that:
- we cache the QID of the root directory at attach time
- during the walk we compare the QID of each path component with the root
  QID to detect if we're in a "/.." situation
- if so, we skip the current component and go to the next one

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-30 19:23:00 +01:00
Greg Kurz
805b5d98c6 9pfs: forbid . and .. in file names
According to the 9P spec http://man.cat-v.org/plan_9/5/open about the
create request:

The names . and .. are special; it is illegal to create files with these
names.

This patch causes the create and lcreate requests to fail with EINVAL if
the file name is either "." or "..".

Even if it isn't explicitly written in the spec, this patch extends the
checking to all requests that may cause a directory entry to be created:

    - mknod
    - rename
    - renameat
    - mkdir
    - link
    - symlink

The unlinkat request also gets patched for consistency (even if
rmdir("foo/..") is expected to fail according to POSIX.1-2001).

The various error values come from the linux manual pages.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-30 19:21:56 +01:00
Greg Kurz
fff39a7ad0 9pfs: forbid illegal path names
Empty path components don't make sense for most commands and may cause
undefined behavior, depending on the backend.

Also, the walk request described in the 9P spec [1] clearly shows that
the client is supposed to send individual path components: the official
linux client never sends portions of path containing the / character for
example.

Moreover, the 9P spec [2] also states that a system can decide to restrict
the set of supported characters used in path components, with an explicit
mention "to remove slashes from name components".

This patch introduces a new name_is_illegal() helper that checks the
names sent by the client are not empty and don't contain unwanted chars.
Since 9pfs is only supported on linux hosts, only the / character is
checked at the moment. When support for other hosts (AKA. win32) is added,
other chars may need to be blacklisted as well.

If a client sends an illegal path component, the request will fail and
ENOENT is returned to the client.

[1] http://man.cat-v.org/plan_9/5/walk
[2] http://man.cat-v.org/plan_9/5/intro

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-30 19:21:39 +01:00
Laurent Vivier
e723b87103 trace-events: fix first line comment in trace-events
Documentation is docs/tracing.txt instead of docs/trace-events.txt.

find . -name trace-events -exec \
     sed -i "s?See docs/trace-events.txt for syntax documentation.?See docs/tracing.txt for syntax documentation.?" \
     {} \;

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-id: 1470669081-17860-1-git-send-email-lvivier@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-12 10:36:01 +01:00
Dr. David Alan Gilbert
18e0e5b240 9pfs: Wrap in vmstate
Forcibly convert it to a vmstate wrapper;  proper conversion
comes later.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-21 20:44:20 +03:00
Paolo Bonzini
0b8b8753e4 coroutine: move entry argument to qemu_coroutine_create
In practice the entry argument is always known at creation time, and
it is confusing that sometimes qemu_coroutine_enter is used with a
non-NULL argument to re-enter a coroutine (this happens in
block/sheepdog.c and tests/test-coroutine.c).  So pass the opaque value
at creation time, for consistency with e.g. aio_bh_new.

Mostly done with the following semantic patch:

@ entry1 @
expression entry, arg, co;
@@
- co = qemu_coroutine_create(entry);
+ co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry2 @
expression entry, arg;
identifier co;
@@
- Coroutine *co = qemu_coroutine_create(entry);
+ Coroutine *co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry3 @
expression entry, arg;
@@
- qemu_coroutine_enter(qemu_coroutine_create(entry), arg);
+ qemu_coroutine_enter(qemu_coroutine_create(entry, arg));

@ reentry @
expression co;
@@
- qemu_coroutine_enter(co, NULL);
+ qemu_coroutine_enter(co);

except for the aforementioned few places where the semantic patch
stumbled (as expected) and for test_co_queue, which would otherwise
produce an uninitialized variable warning.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13 13:26:02 +02:00