diff options
| -rw-r--r-- | drivers/hv/hv_fcopy.c | 194 |
1 files changed, 46 insertions, 148 deletions
diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c index d1475e6aa9ac..6a8ec9fb0869 100644 --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -19,17 +19,13 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#include <linux/semaphore.h> -#include <linux/fs.h> #include <linux/nls.h> #include <linux/workqueue.h> -#include <linux/cdev.h> #include <linux/hyperv.h> #include <linux/sched.h> -#include <linux/uaccess.h> -#include <linux/miscdevice.h> #include "hyperv_vmbus.h" +#include "hv_utils_transport.h" #define WIN8_SRV_MAJOR 1 #define WIN8_SRV_MINOR 1 @@ -53,18 +49,19 @@ static struct { int state; /* hvutil_device_state */ int recv_len; /* number of bytes received. */ struct hv_fcopy_hdr *fcopy_msg; /* current message */ - struct hv_start_fcopy message; /* sent to daemon */ struct vmbus_channel *recv_channel; /* chn we got the request */ u64 recv_req_id; /* request ID. */ void *fcopy_context; /* for the channel callback */ - struct semaphore read_sema; } fcopy_transaction; -static void fcopy_send_data(void); static void fcopy_respond_to_host(int error); +static void fcopy_send_data(struct work_struct *dummy); static void fcopy_timeout_func(struct work_struct *dummy); static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func); +static DECLARE_WORK(fcopy_send_work, fcopy_send_data); +static const char fcopy_devname[] = "vmbus/hv_fcopy"; static u8 *recv_buffer; +static struct hvutil_transport *hvt; static void fcopy_timeout_func(struct work_struct *dummy) { @@ -78,17 +75,6 @@ static void fcopy_timeout_func(struct work_struct *dummy) if (fcopy_transaction.state > HVUTIL_READY) fcopy_transaction.state = HVUTIL_READY; - /* In the case the user-space daemon crashes, hangs or is killed, we - * need to down the semaphore, otherwise, after the daemon starts next - * time, the obsolete data in fcopy_transaction.message or - * fcopy_transaction.fcopy_msg will be used immediately. - * - * NOTE: fcopy_read() happens to get the semaphore (very rare)? We're - * still OK, because we've reported the failure to the host. - */ - if (down_trylock(&fcopy_transaction.read_sema)) - ; - hv_poll_channel(fcopy_transaction.fcopy_context, hv_fcopy_onchannelcallback); } @@ -115,11 +101,13 @@ static int fcopy_handle_handshake(u32 version) return 0; } -static void fcopy_send_data(void) +static void fcopy_send_data(struct work_struct *dummy) { - struct hv_start_fcopy *smsg_out = &fcopy_transaction.message; + struct hv_start_fcopy smsg_out; int operation = fcopy_transaction.fcopy_msg->operation; struct hv_start_fcopy *smsg_in; + void *out_src; + int rc, out_len; /* * The strings sent from the host are encoded in @@ -134,26 +122,39 @@ static void fcopy_send_data(void) switch (operation) { case START_FILE_COPY: - memset(smsg_out, 0, sizeof(struct hv_start_fcopy)); - smsg_out->hdr.operation = operation; + out_len = sizeof(struct hv_start_fcopy); + memset(&smsg_out, 0, out_len); + smsg_out.hdr.operation = operation; smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg; utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH, UTF16_LITTLE_ENDIAN, - (__u8 *)smsg_out->file_name, W_MAX_PATH - 1); + (__u8 *)&smsg_out.file_name, W_MAX_PATH - 1); utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH, UTF16_LITTLE_ENDIAN, - (__u8 *)smsg_out->path_name, W_MAX_PATH - 1); + (__u8 *)&smsg_out.path_name, W_MAX_PATH - 1); - smsg_out->copy_flags = smsg_in->copy_flags; - smsg_out->file_size = smsg_in->file_size; + smsg_out.copy_flags = smsg_in->copy_flags; + smsg_out.file_size = smsg_in->file_size; + out_src = &smsg_out; break; default: + out_src = fcopy_transaction.fcopy_msg; + out_len = fcopy_transaction.recv_len; break; } - up(&fcopy_transaction.read_sema); + + fcopy_transaction.state = HVUTIL_USERSPACE_REQ; + rc = hvutil_transport_send(hvt, out_src, out_len); + if (rc) { + pr_debug("FCP: failed to communicate to the daemon: %d\n", rc); + if (cancel_delayed_work_sync(&fcopy_timeout_work)) { + fcopy_respond_to_host(HV_E_FAIL); + fcopy_transaction.state = HVUTIL_READY; + } + } return; } @@ -255,8 +256,8 @@ void hv_fcopy_onchannelcallback(void *context) /* * Send the information to the user-level daemon. */ + schedule_work(&fcopy_send_work); schedule_delayed_work(&fcopy_timeout_work, 5*HZ); - fcopy_send_data(); return; } icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; @@ -264,69 +265,16 @@ void hv_fcopy_onchannelcallback(void *context) VM_PKT_DATA_INBAND, 0); } -/* - * Create a char device that can support read/write for passing - * the payload. - */ - -static ssize_t fcopy_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos) -{ - void *src; - size_t copy_size; - int operation; - - /* - * Wait until there is something to be read. - */ - if (down_interruptible(&fcopy_transaction.read_sema)) - return -EINTR; - - /* - * The channel may be rescinded and in this case, we will wakeup the - * the thread blocked on the semaphore and we will use the state to - * correctly handle this case. - */ - if (fcopy_transaction.state != HVUTIL_HOSTMSG_RECEIVED) - return -ENODEV; - - operation = fcopy_transaction.fcopy_msg->operation; - - if (operation == START_FILE_COPY) { - src = &fcopy_transaction.message; - copy_size = sizeof(struct hv_start_fcopy); - if (count < copy_size) - return 0; - } else { - src = fcopy_transaction.fcopy_msg; - copy_size = sizeof(struct hv_do_fcopy); - if (count < copy_size) - return 0; - } - if (copy_to_user(buf, src, copy_size)) - return -EFAULT; - - fcopy_transaction.state = HVUTIL_USERSPACE_REQ; - - return copy_size; -} - -static ssize_t fcopy_write(struct file *file, const char __user *buf, - size_t count, loff_t *ppos) +/* Callback when data is received from userspace */ +static int fcopy_on_msg(void *msg, int len) { - int response = 0; + int *val = (int *)msg; - if (count != sizeof(int)) + if (len != sizeof(int)) return -EINVAL; - if (copy_from_user(&response, buf, sizeof(int))) - return -EFAULT; - - if (fcopy_transaction.state == HVUTIL_DEVICE_INIT) { - if (fcopy_handle_handshake(response)) - return -EINVAL; - return sizeof(int); - } + if (fcopy_transaction.state == HVUTIL_DEVICE_INIT) + return fcopy_handle_handshake(*val); if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ) return -EINVAL; @@ -337,78 +285,24 @@ static ssize_t fcopy_write(struct file *file, const char __user *buf, */ if (cancel_delayed_work_sync(&fcopy_timeout_work)) { fcopy_transaction.state = HVUTIL_USERSPACE_RECV; - fcopy_respond_to_host(response); + fcopy_respond_to_host(*val); fcopy_transaction.state = HVUTIL_READY; hv_poll_channel(fcopy_transaction.fcopy_context, hv_fcopy_onchannelcallback); } - return sizeof(int); -} - -static int fcopy_open(struct inode *inode, struct file *f) -{ - /* - * The user level daemon that will open this device is - * really an extension of this driver. We can have only - * active open at a time. - */ - if (fcopy_transaction.state != HVUTIL_DEVICE_INIT) - return -EBUSY; - return 0; } -/* XXX: there are still some tricky corner cases, e.g., - * In an SMP guest, when fcopy_release() runs between - * schedule_delayed_work() and fcopy_send_data(), there is - * still a chance an obsolete message will be queued. - */ -static int fcopy_release(struct inode *inode, struct file *f) +static void fcopy_on_reset(void) { /* * The daemon has exited; reset the state. */ fcopy_transaction.state = HVUTIL_DEVICE_INIT; - if (cancel_delayed_work_sync(&fcopy_timeout_work)) { - /* We haven't up()-ed the semaphore(very rare)? */ - if (down_trylock(&fcopy_transaction.read_sema)) - ; + if (cancel_delayed_work_sync(&fcopy_timeout_work)) fcopy_respond_to_host(HV_E_FAIL); - } - return 0; -} - - -static const struct file_operations fcopy_fops = { - .owner = THIS_MODULE, - .read = fcopy_read, - .write = fcopy_write, - .release = fcopy_release, - .open = fcopy_open, -}; - -static struct miscdevice fcopy_misc = { - .minor = MISC_DYNAMIC_MINOR, - .name = "vmbus/hv_fcopy", - .fops = &fcopy_fops, -}; - -static int fcopy_dev_init(void) -{ - return misc_register(&fcopy_misc); -} - -static void fcopy_dev_deinit(void) -{ - - /* - * Signal the semaphore as the device is - * going away. - */ - up(&fcopy_transaction.read_sema); - misc_deregister(&fcopy_misc); } int hv_fcopy_init(struct hv_util_service *srv) @@ -422,14 +316,18 @@ int hv_fcopy_init(struct hv_util_service *srv) * has registered. */ fcopy_transaction.state = HVUTIL_DEVICE_INIT; - sema_init(&fcopy_transaction.read_sema, 0); - return fcopy_dev_init(); + hvt = hvutil_transport_init(fcopy_devname, 0, 0, + fcopy_on_msg, fcopy_on_reset); + if (!hvt) + return -EFAULT; + + return 0; } void hv_fcopy_deinit(void) { fcopy_transaction.state = HVUTIL_DEVICE_DYING; cancel_delayed_work_sync(&fcopy_timeout_work); - fcopy_dev_deinit(); + hvutil_transport_destroy(hvt); } |