The assumption that the fid cannot be used by any other operation is
wrong. At least, nothing prevents a misbehaving client to create a
file with a given fid, and to pass this fid to some other operation
at the same time (ie, without waiting for the response to the creation
request). The call to v9fs_path_copy() performed by the worker thread
after the file was created can race with any access to the fid path
performed by some other thread. This causes use-after-free issues that
can be detected by ASAN with a custom 9p client.
Unlike other operations that only read the fid path, v9fs_co_open2()
does modify it. It should hence take the write lock.
Cc: P J P <ppandit@redhat.com>
Reported-by: zhibin hu <noirfate@gmail.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
This patchset adds the throttle support for the 9p-local driver.
For now this functionality can be enabled only through qemu cli options.
QMP interface and support to other drivers need further extensions.
To make it simple for other 9p drivers, the throttle code has been put in
separate files.
Signed-off-by: Pradeep Jagadeesh <pradeep.jagadeesh@huawei.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
(pass extra NULL CoMutex * argument to qemu_co_queue_wait(),
added options to qemu-options.hx, Greg Kurz)
Signed-off-by: Greg Kurz <groug@kaod.org>
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>
Most of the 9p code is now virtio agnostic. This patch does a final cleanup:
- drop references to Virtio from the header comments
- fix includes
Also drop a couple of leading empty lines while here.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-18-git-send-email-peter.maydell@linaro.org
Those two files are not virtio specific. Rename them to use generic
names.
Fix includes in various C files. Change define guards and comments in
header files.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
The coroutine files are currently referenced by the block-obj-y
variable. The coroutine functionality though is already used by
more than just the block code. eg migration code uses coroutine
yield. In the future the I/O channel code will also use the
coroutine yield functionality. Since the coroutine code is nicely
self-contained it can be easily built as part of the libqemuutil.a
library, making it widely available.
The headers are also moved into include/qemu, instead of the
include/block directory, since they are now part of the util
codebase, and the impl was never in the block/ directory
either.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently we fail getattr request altogether if we can't read
P9_STATS_GEN for some reason. It breaks valid use cases:
E.g let's assume we have non-readable directory with execution bit set
on host and we export it to client over 9p On host we can chdir into
directory, but not open directory on read and list content.
But if client will try to call getattr (as part of chdir(2)) for the
directory it will fail with -EACCES. It happens because we try to open
the directory on read to call ioctl(FS_IOC_GETVERSION), it fails and we
return the error code to client.
It's excessive. The solution is to make P9_STATS_GEN failure non-fatal
for getattr request. Just don't set P9_STATS_GEN flag in result mask on
failure.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
9P optionally uses the FS_IOC_GETVERSION ioctl to get information about
a file's version (sometimes called generation number).
The code checks for supported filesystems at mount time, but some paths
may come from other mounted filesystems.
Change it to treat unsupported paths the same as unsupported
filesystems, returning 0 in both cases.
Note: ENOTTY is the error code for an unsupported ioctl.
This fix allows booting a linux kernel with the same / filesystem as the
host; otherwise the boot fails when mounting devtmpfs.
Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This enable us to do passthrough equivalent security model on NFS directory.
NFS server mostly do root squashing and don't support xattr. Hence we cannot
use 'passthrough' or 'mapped' security model
Also added "mapped-xattr" security to indicate earlier "mapped" security model
Older name is still supported.
POSIX rules regarding ctime update on chmod are not followed by this security model.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Fsdriver callback that operate on file descriptor need to
differentiate between directory fd and file fd.
Based on the original patch from Sassan Panahinejad <sassan@sassan.me.uk>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
To implement synthetic file system in Qemu we may not really
require file descriptor and Dir *. Make generic code use
V9fsFidOpenState instead.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This patch use file system specific ioctl for getting i_generation
value. Not all file system support the ioctl. So we add an export
specific extended operation and assign right callback for the
file system that support i_generation ioctl
["M. Mohan Kumar" <mohan@in.ibm.com> we can do ioctl only for
regular files and directories on the server]
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Add a new context flag PATHNAME_FSCONTEXT and indicate whether
the fs driver track fid using path names. Also add a private
pointer that help us to track fs driver specific values in there
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This enables us to add handles to track fids later. The
V9fsPath added is similar to V9fsString except that the
size include the NULL byte also.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
On rename we take the write lock and this ensure path
doesn't change as we operate on them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
