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path: root/net/9p/trans_xen.c
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2017-10-23net/9p: Switch to wait_event_killable()Tuomas Tynkkynen
Because userspace gets Very Unhappy when calls like stat() and execve() return -EINTR on 9p filesystem mounts. For instance, when bash is looking in PATH for things to execute and some SIGCHLD interrupts stat(), bash can throw a spurious 'command not found' since it doesn't retry the stat(). In practice, hitting the problem is rare and needs a really slow/bogged down 9p server. Cc: stable@vger.kernel.org Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-18xen/9pfs: p9_trans_xen_init and p9_trans_xen_exit can be staticWei Yongjun
Fixes the following sparse warnings: net/9p/trans_xen.c:528:5: warning: symbol 'p9_trans_xen_init' was not declared. Should it be static? net/9p/trans_xen.c:540:6: warning: symbol 'p9_trans_xen_exit' was not declared. Should it be static? Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-05-18xen/9pfs: fix return value check in xen_9pfs_front_probe()Wei Yongjun
In case of error, the function xenbus_read() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). Fixes: 71ebd71921e4 ("xen/9pfs: connect to the backend") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-05-02xen/9pfs: initialize len to 0 to detect xenbus_read errorsStefano Stabellini
In order to use "len" to check for xenbus_read errors properly, we need to initialize len to 0 before passing it to xenbus_read. CC: dan.carpenter@oracle.com CC: jgross@suse.com CC: boris.ostrovsky@oracle.com CC: Eric Van Hensbergen <ericvh@gmail.com> CC: Ron Minnich <rminnich@sandia.gov> CC: Latchesar Ionkov <lucho@ionkov.net> CC: v9fs-developer@lists.sourceforge.net Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02xen/9pfs: receive responsesStefano Stabellini
Upon receiving a notification from the backend, schedule the p9_xen_response work_struct. p9_xen_response checks if any responses are available, if so, it reads them one by one, calling p9_client_cb to send them up to the 9p layer (p9_client_cb completes the request). Handle the ring following the Xen 9pfs specification. CC: groug@kaod.org CC: jgross@suse.com CC: Eric Van Hensbergen <ericvh@gmail.com> CC: Ron Minnich <rminnich@sandia.gov> CC: Latchesar Ionkov <lucho@ionkov.net> CC: v9fs-developer@lists.sourceforge.net Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02xen/9pfs: send requests to the backendStefano Stabellini
Implement struct p9_trans_module create and close functions by looking at the available Xen 9pfs frontend-backend connections. We don't expect many frontend-backend connections, thus walking a list is OK. Send requests to the backend by copying each request to one of the available rings (each frontend-backend connection comes with multiple rings). Handle the ring and notifications following the 9pfs specification. If there are not enough free bytes on the ring for the request, wait on the wait_queue: the backend will send a notification after consuming more requests. CC: groug@kaod.org CC: jgross@suse.com CC: Eric Van Hensbergen <ericvh@gmail.com> CC: Ron Minnich <rminnich@sandia.gov> CC: Latchesar Ionkov <lucho@ionkov.net> CC: v9fs-developer@lists.sourceforge.net Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02xen/9pfs: connect to the backendStefano Stabellini
Implement functions to handle the xenbus handshake. Upon connection, allocate the rings according to the protocol specification. Initialize a work_struct and a wait_queue. The work_struct will be used to schedule work upon receiving an event channel notification from the backend. The wait_queue will be used to wait when the ring is full and we need to send a new request. CC: groug@kaod.org CC: boris.ostrovsky@oracle.com CC: jgross@suse.com CC: Eric Van Hensbergen <ericvh@gmail.com> CC: Ron Minnich <rminnich@sandia.gov> CC: Latchesar Ionkov <lucho@ionkov.net> CC: v9fs-developer@lists.sourceforge.net Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02xen/9pfs: introduce Xen 9pfs transport driverStefano Stabellini
Introduce the Xen 9pfs transport driver: add struct xenbus_driver to register as a xenbus driver and add struct p9_trans_module to register as v9fs driver. All functions are empty stubs for now. CC: groug@kaod.org CC: jgross@suse.com CC: Eric Van Hensbergen <ericvh@gmail.com> CC: Ron Minnich <rminnich@sandia.gov> CC: Latchesar Ionkov <lucho@ionkov.net> CC: v9fs-developer@lists.sourceforge.net Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>