/* * Network block device - make block devices work over TCP * * Note that you can not swap over this thing, yet. Seems to work but * deadlocks sometimes - you can not swap over TCP in general. * * Copyright 1997-2000 Pavel Machek <pavel@ucw.cz> * Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com> * * This file is released under GPLv2 or later. * * (part of code stolen from loop.c) */ #include <linux/major.h> #include <linux/blkdev.h>#include <linux/module.h>#include <linux/init.h>#include <linux/sched.h>#include <linux/fs.h>#include <linux/bio.h>#include <linux/stat.h>#include <linux/errno.h>#include <linux/file.h>#include <linux/ioctl.h>#include <linux/compiler.h>#include <linux/err.h>#include <linux/kernel.h>#include <net/sock.h> #include <asm/uaccess.h>#include <asm/system.h>#include <asm/types.h> #include <linux/nbd.h> #define LO_MAGIC 0x68797548 #ifdef NDEBUG#define dprintk(flags, fmt...)#else /* NDEBUG */#define dprintk(flags, fmt...) do { \ if (debugflags & (flags)) printk(KERN_DEBUG fmt); \} while (0)#define DBG_IOCTL 0x0004#define DBG_INIT 0x0010#define DBG_EXIT 0x0020#define DBG_BLKDEV 0x0100#define DBG_RX 0x0200#define DBG_TX 0x0400static unsigned int debugflags;#endif /* NDEBUG */ static unsigned int nbds_max = 16;static struct nbd_device nbd_dev[MAX_NBD]; /* * Use just one lock (or at most 1 per NIC). Two arguments for this: * 1. Each NIC is essentially a synchronization point for all servers * accessed through that NIC so there's no need to have more locks * than NICs anyway. * 2. More locks lead to more "Dirty cache line bouncing" which will slow * down each lock to the point where they're actually slower than just * a single lock. * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! */static DEFINE_SPINLOCK(nbd_lock); #ifndef NDEBUGstatic const char *ioctl_cmd_to_ascii(int cmd){ switch (cmd) { case NBD_SET_SOCK: return "set-sock"; case NBD_SET_BLKSIZE: return "set-blksize"; case NBD_SET_SIZE: return "set-size"; case NBD_DO_IT: return "do-it"; case NBD_CLEAR_SOCK: return "clear-sock"; case NBD_CLEAR_QUE: return "clear-que"; case NBD_PRINT_DEBUG: return "print-debug"; case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; case NBD_DISCONNECT: return "disconnect"; case BLKROSET: return "set-read-only"; case BLKFLSBUF: return "flush-buffer-cache"; } return "unknown";} static const char *nbdcmd_to_ascii(int cmd){ switch (cmd) { case NBD_CMD_READ: return "read"; case NBD_CMD_WRITE: return "write"; case NBD_CMD_DISC: return "disconnect"; } return "invalid";}#endif /* NDEBUG */ static void nbd_end_request(struct request *req){ int uptodate = (req->errors == 0) ? 1 : 0; request_queue_t *q = req->q; unsigned long flags; dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, req, uptodate? "done": "failed"); spin_lock_irqsave(q->queue_lock, flags); if (!end_that_request_first(req, uptodate, req->nr_sectors)) { end_that_request_last(req, uptodate); } spin_unlock_irqrestore(q->queue_lock, flags);} /* * Send or receive packet. */static int sock_xmit(struct socket *sock, int send, void *buf, int size, int msg_flags){ int result; struct msghdr msg; struct kvec iov; unsigned long flags; sigset_t oldset; /* Allow interception of SIGKILL only * Don't allow other signals to interrupt the transmission */ spin_lock_irqsave(¤t->sighand->siglock, flags); oldset = current->blocked; sigfillset(¤t->blocked); sigdelsetmask(¤t->blocked, sigmask(SIGKILL)); recalc_sigpending(); spin_unlock_irqrestore(¤t->sighand->siglock, flags); do { sock->sk->sk_allocation = GFP_NOIO; iov.iov_base = buf; iov.iov_len = size; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = msg_flags | MSG_NOSIGNAL; if (send) result = kernel_sendmsg(sock, &msg, &iov, 1, size); else result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); if (signal_pending(current)) { siginfo_t info; spin_lock_irqsave(¤t->sighand->siglock, flags); printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", current->pid, current->comm, dequeue_signal(current, ¤t->blocked, &info)); spin_unlock_irqrestore(¤t->sighand->siglock, flags); result = -EINTR; break; } if (result <= 0) { if (result == 0) result = -EPIPE; /* short read */ break; } size -= result; buf += result; } while (size > 0); spin_lock_irqsave(¤t->sighand->siglock, flags); current->blocked = oldset; recalc_sigpending(); spin_unlock_irqrestore(¤t->sighand->siglock, flags); return result;} static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, int flags){ int result; void *kaddr = kmap(bvec->bv_page); result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); kunmap(bvec->bv_page); return result;} static int nbd_send_req(struct nbd_device *lo, struct request *req){ int result, i, flags; struct nbd_request request; unsigned long size = req->nr_sectors << 9; struct socket *sock = lo->sock; request.magic = htonl(NBD_REQUEST_MAGIC); request.type = htonl(nbd_cmd(req)); request.from = cpu_to_be64((u64) req->sector << 9); request.len = htonl(size); memcpy(request.handle, &req, sizeof(req)); dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", lo->disk->disk_name, req, nbdcmd_to_ascii(nbd_cmd(req)), (unsigned long long)req->sector << 9, req->nr_sectors << 9); result = sock_xmit(sock, 1, &request, sizeof(request), (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0); if (result <= 0) { printk(KERN_ERR "%s: Send control failed (result %d)\n", lo->disk->disk_name, result); goto error_out; } if (nbd_cmd(req) == NBD_CMD_WRITE) { struct bio *bio; /* * we are really probing at internals to determine * whether to set MSG_MORE or not... */ rq_for_each_bio(bio, req) { struct bio_vec *bvec; bio_for_each_segment(bvec, bio, i) { flags = 0; if ((i < (bio->bi_vcnt - 1)) || bio->bi_next) flags = MSG_MORE; dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", lo->disk->disk_name, req, bvec->bv_len); result = sock_send_bvec(sock, bvec, flags); if (result <= 0) { printk(KERN_ERR "%s: Send data failed (result %d)\n", lo->disk->disk_name, result); goto error_out; } } } } return 0; error_out: return 1;} static struct request *nbd_find_request(struct nbd_device *lo, char *handle){ struct request *req; struct list_head *tmp; struct request *xreq; int err; memcpy(&xreq, handle, sizeof(xreq)); err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); if (unlikely(err)) goto out; spin_lock(&lo->queue_lock); list_for_each(tmp, &lo->queue_head) { req = list_entry(tmp, struct request, queuelist); if (req != xreq) continue; list_del_init(&req->queuelist); spin_unlock(&lo->queue_lock); return req; } spin_unlock(&lo->queue_lock); err = -ENOENT; out: return ERR_PTR(err);} static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec){ int result; void *kaddr = kmap(bvec->bv_page); result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len, MSG_WAITALL); kunmap(bvec->bv_page); return result;} /* NULL returned = something went wrong, inform userspace */static struct request *nbd_read_stat(struct nbd_device *lo){ int result; struct nbd_reply reply; struct request *req; struct socket *sock = lo->sock; reply.magic = 0; result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL); if (result <= 0) { printk(KERN_ERR "%s: Receive control failed (result %d)\n", lo->disk->disk_name, result); goto harderror; } if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", lo->disk->disk_name, (unsigned long)ntohl(reply.magic)); result = -EPROTO; goto harderror; } req = nbd_find_request(lo, reply.handle); if (unlikely(IS_ERR(req))) { result = PTR_ERR(req); if (result != -ENOENT) goto harderror; printk(KERN_ERR "%s: Unexpected reply (%p)\n", lo->disk->disk_name, reply.handle); result = -EBADR; goto harderror; } if (ntohl(reply.error)) { printk(KERN_ERR "%s: Other side returned error (%d)\n", lo->disk->disk_name, ntohl(reply.error)); req->errors++; return req; } dprintk(DBG_RX, "%s: request %p: got reply\n", lo->disk->disk_name, req); if (nbd_cmd(req) == NBD_CMD_READ) { int i; struct bio *bio; rq_for_each_bio(bio, req) { struct bio_vec *bvec; bio_for_each_segment(bvec, bio, i) { result = sock_recv_bvec(sock, bvec); if (result <= 0) { printk(KERN_ERR "%s: Receive data failed (result %d)\n", lo->disk->disk_name, result); req->errors++; return req; } dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", lo->disk->disk_name, req, bvec->bv_len); } } } return req;harderror: lo->harderror = result; return NULL;} static ssize_t pid_show(struct gendisk *disk, char *page){ return sprintf(page, "%ld\n", (long) ((struct nbd_device *)disk->private_data)->pid);} static struct disk_attribute pid_attr = { .attr = { .name = "pid", .mode = S_IRUGO }, .show = pid_show,}; static void nbd_do_it(struct nbd_device *lo){ struct request *req; BUG_ON(lo->magic != LO_MAGIC); lo->pid = current->pid; sysfs_create_file(&lo->disk->kobj, &pid_attr.attr); while ((req = nbd_read_stat(lo)) != NULL) nbd_end_request(req); sysfs_remove_file(&lo->disk->kobj, &pid_attr.attr); return;} static void nbd_clear_que(struct nbd_device *lo){ struct request *req; BUG_ON(lo->magic != LO_MAGIC); /* * Because we have set lo->sock to NULL under the tx_lock, all * modifications to the list must have completed by now. For * the same reason, the active_req must be NULL. * * As a consequence, we don't need to take the spin lock while * purging the list here. */ BUG_ON(lo->sock); BUG_ON(lo->active_req); while (!list_empty(&lo->queue_head)) { req = list_entry(lo->queue_head.next, struct request, queuelist); list_del_init(&req->queuelist); req->errors++; nbd_end_request(req); }} /* * We always wait for result of write, for now. It would be nice to make it optional * in future * if ((req->cmd == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } */ static void do_nbd_request(request_queue_t * q){ struct request *req; while ((req = elv_next_request(q)) != NULL) { struct nbd_device *lo; blkdev_dequeue_request(req); dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", req->rq_disk->disk_name, req, req->cmd_type); if (!blk_fs_request(req)) goto error_out; lo = req->rq_disk->private_data; BUG_ON(lo->magic != LO_MAGIC); nbd_cmd(req) = NBD_CMD_READ; if (rq_data_dir(req) == WRITE) { nbd_cmd(req) = NBD_CMD_WRITE; if (lo->flags & NBD_READ_ONLY) { printk(KERN_ERR "%s: Write on read-only\n", lo->disk->disk_name); goto error_out; } } req->errors = 0; spin_unlock_irq(q->queue_lock); mutex_lock(&lo->tx_lock); if (unlikely(!lo->sock)) { mutex_unlock(&lo->tx_lock); printk(KERN_ERR "%s: Attempted send on closed socket\n", lo->disk->disk_name); req->errors++; nbd_end_request(req); spin_lock_irq(q->queue_lock); continue; } lo->active_req = req; if (nbd_send_req(lo, req) != 0) { printk(KERN_ERR "%s: Request send failed\n", lo->disk->disk_name); req->errors++; nbd_end_request(req); } else { spin_lock(&lo->queue_lock); list_add(&req->queuelist, &lo->queue_head); spin_unlock(&lo->queue_lock); } lo->active_req = NULL; mutex_unlock(&lo->tx_lock); wake_up_all(&lo->active_wq); spin_lock_irq(q->queue_lock); continue; error_out: req->errors++; spin_unlock(q->queue_lock); nbd_end_request(req); spin_lock(q->queue_lock); } return;} static int nbd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg){ struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; int error; struct request sreq ; if (!capable(CAP_SYS_ADMIN)) return -EPERM; BUG_ON(lo->magic != LO_MAGIC); Lines 1–500 of 719. 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/* * Network block device - make block devices work over TCP * * Note that you can not swap over this thing, yet. Seems to work but * deadlocks sometimes - you can not swap over TCP in general. * * Copyright 1997-2000 Pavel Machek <pavel@ucw.cz> * Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com> * * This file is released under GPLv2 or later. * * (part of code stolen from loop.c) */ #include <linux/major.h> #include <linux/blkdev.h> #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/fs.h> #include <linux/bio.h> #include <linux/stat.h> #include <linux/errno.h> #include <linux/file.h> #include <linux/ioctl.h> #include <linux/compiler.h> #include <linux/err.h> #include <linux/kernel.h> #include <net/sock.h> #include <asm/uaccess.h> #include <asm/system.h> #include <asm/types.h> #include <linux/nbd.h> #define LO_MAGIC 0x68797548 #ifdef NDEBUG #define dprintk(flags, fmt...) #else /* NDEBUG */ #define dprintk(flags, fmt...) do { \ if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ } while (0) #define DBG_IOCTL 0x0004 #define DBG_INIT 0x0010 #define DBG_EXIT 0x0020 #define DBG_BLKDEV 0x0100 #define DBG_RX 0x0200 #define DBG_TX 0x0400 static unsigned int debugflags; #endif /* NDEBUG */ static unsigned int nbds_max = 16; static struct nbd_device nbd_dev[MAX_NBD]; /* * Use just one lock (or at most 1 per NIC). Two arguments for this: * 1. Each NIC is essentially a synchronization point for all servers * accessed through that NIC so there's no need to have more locks * than NICs anyway. * 2. More locks lead to more "Dirty cache line bouncing" which will slow * down each lock to the point where they're actually slower than just * a single lock. * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! */ static DEFINE_SPINLOCK(nbd_lock); #ifndef NDEBUG static const char *ioctl_cmd_to_ascii(int cmd) { switch (cmd) { case NBD_SET_SOCK: return "set-sock"; case NBD_SET_BLKSIZE: return "set-blksize"; case NBD_SET_SIZE: return "set-size"; case NBD_DO_IT: return "do-it"; case NBD_CLEAR_SOCK: return "clear-sock"; case NBD_CLEAR_QUE: return "clear-que"; case NBD_PRINT_DEBUG: return "print-debug"; case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; case NBD_DISCONNECT: return "disconnect"; case BLKROSET: return "set-read-only"; case BLKFLSBUF: return "flush-buffer-cache"; } return "unknown"; } static const char *nbdcmd_to_ascii(int cmd) { switch (cmd) { case NBD_CMD_READ: return "read"; case NBD_CMD_WRITE: return "write"; case NBD_CMD_DISC: return "disconnect"; } return "invalid"; } #endif /* NDEBUG */ static void nbd_end_request(struct request *req) { int uptodate = (req->errors == 0) ? 1 : 0; request_queue_t *q = req->q; unsigned long flags; dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, req, uptodate? "done": "failed"); spin_lock_irqsave(q->queue_lock, flags); if (!end_that_request_first(req, uptodate, req->nr_sectors)) { end_that_request_last(req, uptodate); } spin_unlock_irqrestore(q->queue_lock, flags); } /* * Send or receive packet. */ static int sock_xmit(struct socket *sock, int send, void *buf, int size, int msg_flags) { int result; struct msghdr msg; struct kvec iov; unsigned long flags; sigset_t oldset; /* Allow interception of SIGKILL only * Don't allow other signals to interrupt the transmission */ spin_lock_irqsave(¤t->sighand->siglock, flags); oldset = current->blocked; sigfillset(¤t->blocked); sigdelsetmask(¤t->blocked, sigmask(SIGKILL)); recalc_sigpending(); spin_unlock_irqrestore(¤t->sighand->siglock, flags); do { sock->sk->sk_allocation = GFP_NOIO; iov.iov_base = buf; iov.iov_len = size; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = msg_flags | MSG_NOSIGNAL; if (send) result = kernel_sendmsg(sock, &msg, &iov, 1, size); else result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); if (signal_pending(current)) { siginfo_t info; spin_lock_irqsave(¤t->sighand->siglock, flags); printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", current->pid, current->comm, dequeue_signal(current, ¤t->blocked, &info)); spin_unlock_irqrestore(¤t->sighand->siglock, flags); result = -EINTR; break; } if (result <= 0) { if (result == 0) result = -EPIPE; /* short read */ break; } size -= result; buf += result; } while (size > 0); spin_lock_irqsave(¤t->sighand->siglock, flags); current->blocked = oldset; recalc_sigpending(); spin_unlock_irqrestore(¤t->sighand->siglock, flags); return result; } static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, int flags) { int result; void *kaddr = kmap(bvec->bv_page); result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); kunmap(bvec->bv_page); return result; } static int nbd_send_req(struct nbd_device *lo, struct request *req) { int result, i, flags; struct nbd_request request; unsigned long size = req->nr_sectors << 9; struct socket *sock = lo->sock; request.magic = htonl(NBD_REQUEST_MAGIC); request.type = htonl(nbd_cmd(req)); request.from = cpu_to_be64((u64) req->sector << 9); request.len = htonl(size); memcpy(request.handle, &req, sizeof(req)); dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", lo->disk->disk_name, req, nbdcmd_to_ascii(nbd_cmd(req)), (unsigned long long)req->sector << 9, req->nr_sectors << 9); result = sock_xmit(sock, 1, &request, sizeof(request), (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0); if (result <= 0) { printk(KERN_ERR "%s: Send control failed (result %d)\n", lo->disk->disk_name, result); goto error_out; } if (nbd_cmd(req) == NBD_CMD_WRITE) { struct bio *bio; /* * we are really probing at internals to determine * whether to set MSG_MORE or not... */ rq_for_each_bio(bio, req) { struct bio_vec *bvec; bio_for_each_segment(bvec, bio, i) { flags = 0; if ((i < (bio->bi_vcnt - 1)) || bio->bi_next) flags = MSG_MORE; dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", lo->disk->disk_name, req, bvec->bv_len); result = sock_send_bvec(sock, bvec, flags); if (result <= 0) { printk(KERN_ERR "%s: Send data failed (result %d)\n", lo->disk->disk_name, result); goto error_out; } } } } return 0; error_out: return 1; } static struct request *nbd_find_request(struct nbd_device *lo, char *handle) { struct request *req; struct list_head *tmp; struct request *xreq; int err; memcpy(&xreq, handle, sizeof(xreq)); err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); if (unlikely(err)) goto out; spin_lock(&lo->queue_lock); list_for_each(tmp, &lo->queue_head) { req = list_entry(tmp, struct request, queuelist); if (req != xreq) continue; list_del_init(&req->queuelist); spin_unlock(&lo->queue_lock); return req; } spin_unlock(&lo->queue_lock); err = -ENOENT; out: return ERR_PTR(err); } static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec) { int result; void *kaddr = kmap(bvec->bv_page); result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len, MSG_WAITALL); kunmap(bvec->bv_page); return result; } /* NULL returned = something went wrong, inform userspace */ static struct request *nbd_read_stat(struct nbd_device *lo) { int result; struct nbd_reply reply; struct request *req; struct socket *sock = lo->sock; reply.magic = 0; result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL); if (result <= 0) { printk(KERN_ERR "%s: Receive control failed (result %d)\n", lo->disk->disk_name, result); goto harderror; } if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", lo->disk->disk_name, (unsigned long)ntohl(reply.magic)); result = -EPROTO; goto harderror; } req = nbd_find_request(lo, reply.handle); if (unlikely(IS_ERR(req))) { result = PTR_ERR(req); if (result != -ENOENT) goto harderror; printk(KERN_ERR "%s: Unexpected reply (%p)\n", lo->disk->disk_name, reply.handle); result = -EBADR; goto harderror; } if (ntohl(reply.error)) { printk(KERN_ERR "%s: Other side returned error (%d)\n", lo->disk->disk_name, ntohl(reply.error)); req->errors++; return req; } dprintk(DBG_RX, "%s: request %p: got reply\n", lo->disk->disk_name, req); if (nbd_cmd(req) == NBD_CMD_READ) { int i; struct bio *bio; rq_for_each_bio(bio, req) { struct bio_vec *bvec; bio_for_each_segment(bvec, bio, i) { result = sock_recv_bvec(sock, bvec); if (result <= 0) { printk(KERN_ERR "%s: Receive data failed (result %d)\n", lo->disk->disk_name, result); req->errors++; return req; } dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", lo->disk->disk_name, req, bvec->bv_len); } } } return req; harderror: lo->harderror = result; return NULL; } static ssize_t pid_show(struct gendisk *disk, char *page) { return sprintf(page, "%ld\n", (long) ((struct nbd_device *)disk->private_data)->pid); } static struct disk_attribute pid_attr = { .attr = { .name = "pid", .mode = S_IRUGO }, .show = pid_show, }; static void nbd_do_it(struct nbd_device *lo) { struct request *req; BUG_ON(lo->magic != LO_MAGIC); lo->pid = current->pid; sysfs_create_file(&lo->disk->kobj, &pid_attr.attr); while ((req = nbd_read_stat(lo)) != NULL) nbd_end_request(req); sysfs_remove_file(&lo->disk->kobj, &pid_attr.attr); return; } static void nbd_clear_que(struct nbd_device *lo) { struct request *req; BUG_ON(lo->magic != LO_MAGIC); /* * Because we have set lo->sock to NULL under the tx_lock, all * modifications to the list must have completed by now. For * the same reason, the active_req must be NULL. * * As a consequence, we don't need to take the spin lock while * purging the list here. */ BUG_ON(lo->sock); BUG_ON(lo->active_req); while (!list_empty(&lo->queue_head)) { req = list_entry(lo->queue_head.next, struct request, queuelist); list_del_init(&req->queuelist); req->errors++; nbd_end_request(req); } } /* * We always wait for result of write, for now. It would be nice to make it optional * in future * if ((req->cmd == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } */ static void do_nbd_request(request_queue_t * q) { struct request *req; while ((req = elv_next_request(q)) != NULL) { struct nbd_device *lo; blkdev_dequeue_request(req); dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", req->rq_disk->disk_name, req, req->cmd_type); if (!blk_fs_request(req)) goto error_out; lo = req->rq_disk->private_data; BUG_ON(lo->magic != LO_MAGIC); nbd_cmd(req) = NBD_CMD_READ; if (rq_data_dir(req) == WRITE) { nbd_cmd(req) = NBD_CMD_WRITE; if (lo->flags & NBD_READ_ONLY) { printk(KERN_ERR "%s: Write on read-only\n", lo->disk->disk_name); goto error_out; } } req->errors = 0; spin_unlock_irq(q->queue_lock); mutex_lock(&lo->tx_lock); if (unlikely(!lo->sock)) { mutex_unlock(&lo->tx_lock); printk(KERN_ERR "%s: Attempted send on closed socket\n", lo->disk->disk_name); req->errors++; nbd_end_request(req); spin_lock_irq(q->queue_lock); continue; } lo->active_req = req; if (nbd_send_req(lo, req) != 0) { printk(KERN_ERR "%s: Request send failed\n", lo->disk->disk_name); req->errors++; nbd_end_request(req); } else { spin_lock(&lo->queue_lock); list_add(&req->queuelist, &lo->queue_head); spin_unlock(&lo->queue_lock); } lo->active_req = NULL; mutex_unlock(&lo->tx_lock); wake_up_all(&lo->active_wq); spin_lock_irq(q->queue_lock); continue; error_out: req->errors++; spin_unlock(q->queue_lock); nbd_end_request(req); spin_lock(q->queue_lock); } return; } static int nbd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; int error; struct request sreq ; if (!capable(CAP_SYS_ADMIN)) return -EPERM; BUG_ON(lo->magic != LO_MAGIC);