cregit-Linux how code gets into the kernel

Release 4.7 drivers/block/nbd.c

Directory: drivers/block
/*
 * 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, 2008 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/mutex.h>
#include <linux/compiler.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/net.h>
#include <linux/kthread.h>
#include <linux/types.h>
#include <linux/debugfs.h>

#include <asm/uaccess.h>
#include <asm/types.h>

#include <linux/nbd.h>


struct nbd_device {
	
u32 flags;
	
struct socket * sock;	/* If == NULL, device is not ready, yet */
	
int magic;

	
spinlock_t queue_lock;
	
struct list_head queue_head;	/* Requests waiting result */
	
struct request *active_req;
	
wait_queue_head_t active_wq;
	
struct list_head waiting_queue;	/* Requests to be sent */
	
wait_queue_head_t waiting_wq;

	
struct mutex tx_lock;
	
struct gendisk *disk;
	
int blksize;
	
loff_t bytesize;
	
int xmit_timeout;
	
bool timedout;
	
bool disconnect; /* a disconnect has been requested by user */

	
struct timer_list timeout_timer;
	/* protects initialization and shutdown of the socket */
	
spinlock_t sock_lock;
	
struct task_struct *task_recv;
	
struct task_struct *task_send;

#if IS_ENABLED(CONFIG_DEBUG_FS)
	
struct dentry *dbg_dir;
#endif
};

#if IS_ENABLED(CONFIG_DEBUG_FS)

static struct dentry *nbd_dbg_dir;
#endif


#define nbd_name(nbd) ((nbd)->disk->disk_name)


#define NBD_MAGIC 0x68797548


static unsigned int nbds_max = 16;

static struct nbd_device *nbd_dev;

static int max_part;

/*
 * 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);


static inline struct device *nbd_to_dev(struct nbd_device *nbd) { return disk_to_dev(nbd->disk); }

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markus pargmannmarkus pargmann1463.64%150.00%
andrew mortonandrew morton836.36%150.00%
Total22100.00%2100.00%


static bool nbd_is_connected(struct nbd_device *nbd) { return !!nbd->task_recv; }

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markus pargmannmarkus pargmann18100.00%1100.00%
Total18100.00%1100.00%


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"; case NBD_CMD_FLUSH: return "flush"; case NBD_CMD_TRIM: return "trim/discard"; } return "invalid"; }

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PersonTokensPropCommitsCommitProp
andrew mortonandrew morton3876.00%133.33%
paul clementspaul clements612.00%133.33%
alex blighalex bligh612.00%133.33%
Total50100.00%3100.00%


static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev) { bdev->bd_inode->i_size = 0; set_capacity(nbd->disk, 0); kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann49100.00%1100.00%
Total49100.00%1100.00%


static void nbd_size_update(struct nbd_device *nbd, struct block_device *bdev) { if (!nbd_is_connected(nbd)) return; bdev->bd_inode->i_size = nbd->bytesize; set_capacity(nbd->disk, nbd->bytesize >> 9); kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); }

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PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann61100.00%1100.00%
Total61100.00%1100.00%


static int nbd_size_set(struct nbd_device *nbd, struct block_device *bdev, int blocksize, int nr_blocks) { int ret; ret = set_blocksize(bdev, blocksize); if (ret) return ret; nbd->blksize = blocksize; nbd->bytesize = (loff_t)blocksize * (loff_t)nr_blocks; nbd_size_update(nbd, bdev); return 0; }

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PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann71100.00%1100.00%
Total71100.00%1100.00%


static void nbd_end_request(struct nbd_device *nbd, struct request *req) { int error = req->errors ? -EIO : 0; struct request_queue *q = req->q; unsigned long flags; dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", req, error ? "failed" : "done"); spin_lock_irqsave(q->queue_lock, flags); __blk_end_request_all(req, error); spin_unlock_irqrestore(q->queue_lock, flags); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig5464.29%116.67%
markus pargmannmarkus pargmann1113.10%116.67%
andrew mortonandrew morton910.71%116.67%
kiyoshi uedakiyoshi ueda78.33%116.67%
jens axboejens axboe22.38%116.67%
tejun heotejun heo11.19%116.67%
Total84100.00%6100.00%

/* * Forcibly shutdown the socket causing all listeners to error */
static void sock_shutdown(struct nbd_device *nbd) { spin_lock_irq(&nbd->sock_lock); if (!nbd->sock) { spin_unlock_irq(&nbd->sock_lock); return; } dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n"); kernel_sock_shutdown(nbd->sock, SHUT_RDWR); sockfd_put(nbd->sock); nbd->sock = NULL; spin_unlock_irq(&nbd->sock_lock); del_timer(&nbd->timeout_timer); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann4349.43%342.86%
paul clementspaul clements3135.63%114.29%
americo wangamerico wang66.90%114.29%
wanlong gaowanlong gao55.75%114.29%
trond myklebusttrond myklebust22.30%114.29%
Total87100.00%7100.00%


static void nbd_xmit_timeout(unsigned long arg) { struct nbd_device *nbd = (struct nbd_device *)arg; unsigned long flags; if (list_empty(&nbd->queue_head)) return; spin_lock_irqsave(&nbd->sock_lock, flags); nbd->timedout = true; if (nbd->sock) kernel_sock_shutdown(nbd->sock, SHUT_RDWR); spin_unlock_irqrestore(&nbd->sock_lock, flags); dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n"); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann6371.59%480.00%
paul clementspaul clements2528.41%120.00%
Total88100.00%5100.00%

/* * Send or receive packet. */
static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, int msg_flags) { struct socket *sock = nbd->sock; int result; struct msghdr msg; struct kvec iov; unsigned long pflags = current->flags; if (unlikely(!sock)) { dev_err(disk_to_dev(nbd->disk), "Attempted %s on closed socket in sock_xmit\n", (send ? "send" : "recv")); return -EINVAL; } current->flags |= PF_MEMALLOC; do { sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; 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, msg.msg_flags); if (result <= 0) { if (result == 0) result = -EPIPE; /* short read */ break; } size -= result; buf += result; } while (size > 0); tsk_restore_flags(current, pflags, PF_MEMALLOC); if (!send && nbd->xmit_timeout) mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout); return result; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git12949.05%318.75%
mike snitzermike snitzer2710.27%16.25%
mel gormanmel gorman259.51%16.25%
markus pargmannmarkus pargmann238.75%16.25%
andrew mortonandrew morton176.46%212.50%
al viroal viro134.94%16.25%
paul clementspaul clements93.42%16.25%
linus torvaldslinus torvalds72.66%212.50%
americo wangamerico wang62.28%16.25%
namhyung kimnamhyung kim31.14%16.25%
wanlong gaowanlong gao31.14%16.25%
david s. millerdavid s. miller10.38%16.25%
Total263100.00%16100.00%


static inline int sock_send_bvec(struct nbd_device *nbd, struct bio_vec *bvec, int flags) { int result; void *kaddr = kmap(bvec->bv_page); result = sock_xmit(nbd, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); kunmap(bvec->bv_page); return result; }

Contributors

PersonTokensPropCommitsCommitProp
lou langholtzlou langholtz5990.77%125.00%
andrew mortonandrew morton34.62%125.00%
wanlong gaowanlong gao23.08%125.00%
paul clementspaul clements11.54%125.00%
Total65100.00%4100.00%

/* always call with the tx_lock held */
static int nbd_send_req(struct nbd_device *nbd, struct request *req) { int result, flags; struct nbd_request request; unsigned long size = blk_rq_bytes(req); u32 type; if (req->cmd_type == REQ_TYPE_DRV_PRIV) type = NBD_CMD_DISC; else if (req->cmd_flags & REQ_DISCARD) type = NBD_CMD_TRIM; else if (req->cmd_flags & REQ_FLUSH) type = NBD_CMD_FLUSH; else if (rq_data_dir(req) == WRITE) type = NBD_CMD_WRITE; else type = NBD_CMD_READ; memset(&request, 0, sizeof(request)); request.magic = htonl(NBD_REQUEST_MAGIC); request.type = htonl(type); if (type != NBD_CMD_FLUSH && type != NBD_CMD_DISC) { request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); request.len = htonl(size); } memcpy(request.handle, &req, sizeof(req)); dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", req, nbdcmd_to_ascii(type), (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); result = sock_xmit(nbd, 1, &request, sizeof(request), (type == NBD_CMD_WRITE) ? MSG_MORE : 0); if (result <= 0) { dev_err(disk_to_dev(nbd->disk), "Send control failed (result %d)\n", result); return -EIO; } if (type == NBD_CMD_WRITE) { struct req_iterator iter; struct bio_vec bvec; /* * we are really probing at internals to determine * whether to set MSG_MORE or not... */ rq_for_each_segment(bvec, req, iter) { flags = 0; if (!rq_iter_last(bvec, iter)) flags = MSG_MORE; dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", req, bvec.bv_len); result = sock_send_bvec(nbd, &bvec, flags); if (result <= 0) { dev_err(disk_to_dev(nbd->disk), "Send data failed (result %d)\n", result); return -EIO; } } } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git11731.88%313.04%
christoph hellwigchristoph hellwig6617.98%14.35%
linus torvaldslinus torvalds4211.44%28.70%
andrew mortonandrew morton4211.44%313.04%
markus pargmannmarkus pargmann205.45%28.70%
hani benhabileshani benhabiles174.63%14.35%
tejun heotejun heo123.27%28.70%
americo wangamerico wang123.27%14.35%
neil brownneil brown123.27%14.35%
wanlong gaowanlong gao71.91%14.35%
alex blighalex bligh61.63%14.35%
paul clementspaul clements51.36%14.35%
dave jonesdave jones51.36%14.35%
kent overstreetkent overstreet30.82%28.70%
lou langholtzlou langholtz10.27%14.35%
Total367100.00%23100.00%


static struct request *nbd_find_request(struct nbd_device *nbd, struct request *xreq) { struct request *req, *tmp; int err; err = wait_event_interruptible(nbd->active_wq, nbd->active_req != xreq); if (unlikely(err)) return ERR_PTR(err); spin_lock(&nbd->queue_lock); list_for_each_entry_safe(req, tmp, &nbd->queue_head, queuelist) { if (req != xreq) continue; list_del_init(&req->queuelist); spin_unlock(&nbd->queue_lock); return req; } spin_unlock(&nbd->queue_lock); return ERR_PTR(-ENOENT); }

Contributors

PersonTokensPropCommitsCommitProp
dave jonesdave jones6857.63%228.57%
herbert xuherbert xu2622.03%114.29%
cheng renquancheng renquan97.63%228.57%
markus pargmannmarkus pargmann86.78%114.29%
wanlong gaowanlong gao75.93%114.29%
Total118100.00%7100.00%


static inline int sock_recv_bvec(struct nbd_device *nbd, struct bio_vec *bvec) { int result; void *kaddr = kmap(bvec->bv_page); result = sock_xmit(nbd, 0, kaddr + bvec->bv_offset, bvec->bv_len, MSG_WAITALL); kunmap(bvec->bv_page); return result; }

Contributors

PersonTokensPropCommitsCommitProp
lou langholtzlou langholtz5690.32%125.00%
andrew mortonandrew morton34.84%125.00%
wanlong gaowanlong gao23.23%125.00%
paul clementspaul clements11.61%125.00%
Total62100.00%4100.00%

/* NULL returned = something went wrong, inform userspace */
static struct request *nbd_read_stat(struct nbd_device *nbd) { int result; struct nbd_reply reply; struct request *req; reply.magic = 0; result = sock_xmit(nbd, 0, &reply, sizeof(reply), MSG_WAITALL); if (result <= 0) { dev_err(disk_to_dev(nbd->disk), "Receive control failed (result %d)\n", result); return ERR_PTR(result); } if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", (unsigned long)ntohl(reply.magic)); return ERR_PTR(-EPROTO); } req = nbd_find_request(nbd, *(struct request **)reply.handle); if (IS_ERR(req)) { result = PTR_ERR(req); if (result != -ENOENT) return ERR_PTR(result); dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%p)\n", reply.handle); return ERR_PTR(-EBADR); } if (ntohl(reply.error)) { dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", ntohl(reply.error)); req->errors++; return req; } dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", req); if (rq_data_dir(req) != WRITE) { struct req_iterator iter; struct bio_vec bvec; rq_for_each_segment(bvec, req, iter) { result = sock_recv_bvec(nbd, &bvec); if (result <= 0) { dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", result); req->errors++; return req; } dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n", req, bvec.bv_len); } } return req; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git10130.70%28.70%
andrew mortonandrew morton5617.02%313.04%
michal feixmichal feix3911.85%28.70%
markus pargmannmarkus pargmann3410.33%28.70%
americo wangamerico wang309.12%14.35%
herbert xuherbert xu175.17%14.35%
lou langholtzlou langholtz113.34%14.35%
wanlong gaowanlong gao113.34%14.35%
linus torvaldslinus torvalds82.43%417.39%
cheng renquancheng renquan72.13%14.35%
neil brownneil brown51.52%14.35%
dave jonesdave jones41.22%14.35%
christoph hellwigchristoph hellwig30.91%14.35%
kent overstreetkent overstreet20.61%14.35%
adrian bunkadrian bunk10.30%14.35%
Total329100.00%23100.00%


static ssize_t pid_show(struct device *dev, struct device_attribute *attr, char *buf) { struct gendisk *disk = dev_to_disk(dev); struct nbd_device *nbd = (struct nbd_device *)disk->private_data; return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv)); }

Contributors

PersonTokensPropCommitsCommitProp
paul clementspaul clements2338.98%133.33%
kay sieverskay sievers1830.51%133.33%
markus pargmannmarkus pargmann1830.51%133.33%
Total59100.00%3100.00%

static struct device_attribute pid_attr = { .attr = { .name = "pid", .mode = S_IRUGO}, .show = pid_show, };
static int nbd_thread_recv(struct nbd_device *nbd, struct block_device *bdev) { struct request *req; int ret; BUG_ON(nbd->magic != NBD_MAGIC); sk_set_memalloc(nbd->sock->sk); nbd->task_recv = current; ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr); if (ret) { dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); nbd->task_recv = NULL; return ret; } nbd_size_update(nbd, bdev); while (1) { req = nbd_read_stat(nbd); if (IS_ERR(req)) { ret = PTR_ERR(req); break; } nbd_end_request(nbd, req); } nbd_size_clear(nbd, bdev); device_remove_file(disk_to_dev(nbd->disk), &pid_attr); nbd->task_recv = NULL; return ret; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann6640.49%635.29%
americo wangamerico wang2917.79%317.65%
pre-gitpre-git2314.11%15.88%
paul clementspaul clements127.36%15.88%
andrew mortonandrew morton95.52%15.88%
mel gormanmel gorman95.52%15.88%
wanlong gaowanlong gao84.91%15.88%
pavel machekpavel machek31.84%15.88%
tejun heotejun heo31.84%15.88%
adrian bunkadrian bunk10.61%15.88%
Total163100.00%17100.00%


static void nbd_clear_que(struct nbd_device *nbd) { struct request *req; BUG_ON(nbd->magic != NBD_MAGIC); /* * Because we have set nbd->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(nbd->sock); BUG_ON(nbd->active_req); while (!list_empty(&nbd->queue_head)) { req = list_entry(nbd->queue_head.next, struct request, queuelist); list_del_init(&req->queuelist); req->errors++; nbd_end_request(nbd, req); } while (!list_empty(&nbd->waiting_queue)) { req = list_entry(nbd->waiting_queue.next, struct request, queuelist); list_del_init(&req->queuelist); req->errors++; nbd_end_request(nbd, req); } dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n"); }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git5033.33%323.08%
paul clementspaul clements4731.33%17.69%
dave jonesdave jones1711.33%215.38%
markus pargmannmarkus pargmann1610.67%215.38%
herbert xuherbert xu85.33%17.69%
wanlong gaowanlong gao85.33%17.69%
pavel machekpavel machek21.33%17.69%
linus torvaldslinus torvalds10.67%17.69%
adrian bunkadrian bunk10.67%17.69%
Total150100.00%13100.00%


static void nbd_handle_req(struct nbd_device *nbd, struct request *req) { if (req->cmd_type != REQ_TYPE_FS) goto error_out; if (rq_data_dir(req) == WRITE && (nbd->flags & NBD_FLAG_READ_ONLY)) { dev_err(disk_to_dev(nbd->disk), "Write on read-only\n"); goto error_out; } req->errors = 0; mutex_lock(&nbd->tx_lock); if (unlikely(!nbd->sock)) { mutex_unlock(&nbd->tx_lock); dev_err(disk_to_dev(nbd->disk), "Attempted send on closed socket\n"); goto error_out; } nbd->active_req = req; if (nbd->xmit_timeout && list_empty_careful(&nbd->queue_head)) mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout); if (nbd_send_req(nbd, req) != 0) { dev_err(disk_to_dev(nbd->disk), "Request send failed\n"); req->errors++; nbd_end_request(nbd, req); } else { spin_lock(&nbd->queue_lock); list_add_tail(&req->queuelist, &nbd->queue_head); spin_unlock(&nbd->queue_lock); } nbd->active_req = NULL; mutex_unlock(&nbd->tx_lock); wake_up_all(&nbd->active_wq); return; error_out: req->errors++; nbd_end_request(nbd, req); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu5020.00%13.70%
markus pargmannmarkus pargmann3212.80%27.41%
pre-gitpre-git2911.60%414.81%
alan coxalan cox2710.80%13.70%
americo wangamerico wang187.20%13.70%
laurent vivierlaurent vivier187.20%13.70%
wanlong gaowanlong gao156.00%13.70%
andrew mortonandrew morton156.00%27.41%
paul clementspaul clements145.60%311.11%
linus torvaldslinus torvalds104.00%13.70%
christoph hellwigchristoph hellwig62.40%27.41%
pavel machekpavel machek41.60%27.41%
al viroal viro31.20%13.70%
ingo molnaringo molnar31.20%13.70%
dave jonesdave jones31.20%13.70%
jens axboejens axboe20.80%27.41%
chetan lokechetan loke10.40%13.70%
Total250100.00%27100.00%


static int nbd_thread_send(void *data) { struct nbd_device *nbd = data; struct request *req; nbd->task_send = current; set_user_nice(current, MIN_NICE); while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) { /* wait for something to do */ wait_event_interruptible(nbd->waiting_wq, kthread_should_stop() || !list_empty(&nbd->waiting_queue)); /* extract request */ if (list_empty(&nbd->waiting_queue)) continue; spin_lock_irq(&nbd->queue_lock); req = list_entry(nbd->waiting_queue.next, struct request, queuelist); list_del_init(&req->queuelist); spin_unlock_irq(&nbd->queue_lock); /* handle request */ nbd_handle_req(nbd, req); } nbd->task_send = NULL; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
laurent vivierlaurent vivier10977.30%112.50%
markus pargmannmarkus pargmann139.22%225.00%
wanlong gaowanlong gao96.38%112.50%
pre-gitpre-git74.96%225.00%
linus torvaldslinus torvalds21.42%112.50%
dongsheng yangdongsheng yang10.71%112.50%
Total141100.00%8100.00%

/* * We always wait for result of write, for now. It would be nice to make it optional * in future * if ((rq_data_dir(req) == WRITE) && (nbd->flags & NBD_WRITE_NOCHK)) * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } */
static void nbd_request_handler(struct request_queue *q) __releases(q->queue_lock) __acquires(q->queue_lock) { struct request *req; while ((req = blk_fetch_request(q)) != NULL) { struct nbd_device *nbd; spin_unlock_irq(q->queue_lock); nbd = req->rq_disk->private_data; BUG_ON(nbd->magic != NBD_MAGIC); dev_dbg(nbd_to_dev(nbd), "request %p: dequeued (flags=%x)\n", req, req->cmd_type); if (unlikely(!nbd->sock)) { dev_err_ratelimited(disk_to_dev(nbd->disk), "Attempted send on closed socket\n"); req->errors++; nbd_end_request(nbd, req); spin_lock_irq(q->queue_lock); continue; } spin_lock_irq(&nbd->queue_lock); list_add_tail(&req->queuelist, &nbd->waiting_queue); spin_unlock_irq(&nbd->queue_lock); wake_up(&nbd->waiting_wq); spin_lock_irq(q->queue_lock); } }

Contributors

PersonTokensPropCommitsCommitProp
laurent vivierlaurent vivier8045.45%18.33%
paul clementspaul clements3419.32%18.33%
markus pargmannmarkus pargmann1910.80%216.67%
alex elderalex elder126.82%18.33%
wanlong gaowanlong gao105.68%18.33%
pre-gitpre-git84.55%216.67%
linus torvaldslinus torvalds63.41%18.33%
americo wangamerico wang52.84%18.33%
dan streetmandan streetman10.57%18.33%
tejun heotejun heo10.57%18.33%
Total176100.00%12100.00%


static int nbd_set_socket(struct nbd_device *nbd, struct socket *sock) { int ret = 0; spin_lock_irq(&nbd->sock_lock); if (nbd->sock) { ret = -EBUSY; goto out; } nbd->sock = sock; out: spin_unlock_irq(&nbd->sock_lock); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann64100.00%1100.00%
Total64100.00%1100.00%

/* Reset all properties of an NBD device */
static void nbd_reset(struct nbd_device *nbd) { nbd->disconnect = false; nbd->timedout = false; nbd->blksize = 1024; nbd->bytesize = 0; set_capacity(nbd->disk, 0); nbd->flags = 0; nbd->xmit_timeout = 0; queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); del_timer_sync(&nbd->timeout_timer); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann75100.00%1100.00%
Total75100.00%1100.00%


static void nbd_bdev_reset(struct block_device *bdev) { set_device_ro(bdev, false); bdev->bd_inode->i_size = 0; if (max_part > 0) { blkdev_reread_part(bdev); bdev->bd_invalidated = 1; } }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann45100.00%1100.00%
Total45100.00%1100.00%


static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev) { if (nbd->flags & NBD_FLAG_READ_ONLY) set_device_ro(bdev, true); if (nbd->flags & NBD_FLAG_SEND_TRIM) queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); if (nbd->flags & NBD_FLAG_SEND_FLUSH) blk_queue_write_cache(nbd->disk->queue, true, false); else blk_queue_write_cache(nbd->disk->queue, false, false); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann7790.59%150.00%
jens axboejens axboe89.41%150.00%
Total85100.00%2100.00%

static int nbd_dev_dbg_init(struct nbd_device *nbd); static void nbd_dev_dbg_close(struct nbd_device *nbd); /* Must be called with tx_lock held */
static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, unsigned int cmd, unsigned long arg) { switch (cmd) { case NBD_DISCONNECT: { struct request sreq; dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); if (!nbd->sock) return -EINVAL; mutex_unlock(&nbd->tx_lock); fsync_bdev(bdev); mutex_lock(&nbd->tx_lock); blk_rq_init(NULL, &sreq); sreq.cmd_type = REQ_TYPE_DRV_PRIV; /* Check again after getting mutex back. */ if (!nbd->sock) return -EINVAL; nbd->disconnect = true; nbd_send_req(nbd, &sreq); return 0; } case NBD_CLEAR_SOCK: sock_shutdown(nbd); nbd_clear_que(nbd); BUG_ON(!list_empty(&nbd->queue_head)); BUG_ON(!list_empty(&nbd->waiting_queue)); kill_bdev(bdev); return 0; case NBD_SET_SOCK: { int err; struct socket *sock = sockfd_lookup(arg, &err); if (!sock) return err; err = nbd_set_socket(nbd, sock); if (!err && max_part) bdev->bd_invalidated = 1; return err; } case NBD_SET_BLKSIZE: { loff_t bsize = div_s64(nbd->bytesize, arg); return nbd_size_set(nbd, bdev, arg, bsize); } case NBD_SET_SIZE: return nbd_size_set(nbd, bdev, nbd->blksize, arg / nbd->blksize); case NBD_SET_SIZE_BLOCKS: return nbd_size_set(nbd, bdev, nbd->blksize, arg); case NBD_SET_TIMEOUT: nbd->xmit_timeout = arg * HZ; if (arg) mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout); else del_timer_sync(&nbd->timeout_timer); return 0; case NBD_SET_FLAGS: nbd->flags = arg; return 0; case NBD_DO_IT: { struct task_struct *thread; int error; if (nbd->task_recv) return -EBUSY; if (!nbd->sock) return -EINVAL; mutex_unlock(&nbd->tx_lock); nbd_parse_flags(nbd, bdev); thread = kthread_run(nbd_thread_send, nbd, "%s", nbd_name(nbd)); if (IS_ERR(thread)) { mutex_lock(&nbd->tx_lock); return PTR_ERR(thread); } nbd_dev_dbg_init(nbd); error = nbd_thread_recv(nbd, bdev); nbd_dev_dbg_close(nbd); kthread_stop(thread); mutex_lock(&nbd->tx_lock); sock_shutdown(nbd); nbd_clear_que(nbd); kill_bdev(bdev); nbd_bdev_reset(bdev); if (nbd->disconnect) /* user requested, ignore socket errors */ error = 0; if (nbd->timedout) error = -ETIMEDOUT; nbd_reset(nbd); return error; } case NBD_CLEAR_QUE: /* * This is for compatibility only. The queue is always cleared * by NBD_DO_IT or NBD_CLEAR_SOCK. */ return 0; case NBD_PRINT_DEBUG: dev_info(disk_to_dev(nbd->disk), "next = %p, prev = %p, head = %p\n", nbd->queue_head.next, nbd->queue_head.prev, &nbd->queue_head); return 0; } return -ENOTTY; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann12422.10%1224.00%
pre-gitpre-git12121.57%612.00%
pavel machekpavel machek5810.34%24.00%
paul clementspaul clements529.27%510.00%
paolo bonzinipaolo bonzini458.02%24.00%
laurent vivierlaurent vivier386.77%24.00%
wanlong gaowanlong gao295.17%12.00%
andrew mortonandrew morton284.99%510.00%
al viroal viro234.10%510.00%
americo wangamerico wang152.67%24.00%
alan coxalan cox91.60%12.00%
fujita tomonorifujita tomonori81.43%12.00%
arnd bergmannarnd bergmann30.53%12.00%
herbert xuherbert xu20.36%12.00%
alex blighalex bligh20.36%12.00%
kees cookkees cook20.36%12.00%
jens axboejens axboe10.18%12.00%
christoph hellwigchristoph hellwig10.18%12.00%
Total561100.00%50100.00%


static int nbd_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { struct nbd_device *nbd = bdev->bd_disk->private_data; int error; if (!capable(CAP_SYS_ADMIN)) return -EPERM; BUG_ON(nbd->magic != NBD_MAGIC); mutex_lock(&nbd->tx_lock); error = __nbd_ioctl(bdev, nbd, cmd, arg); mutex_unlock(&nbd->tx_lock); return error; }

Contributors

PersonTokensPropCommitsCommitProp
pavel machekpavel machek7887.64%125.00%
wanlong gaowanlong gao66.74%125.00%
arnd bergmannarnd bergmann33.37%125.00%
pre-gitpre-git22.25%125.00%
Total89100.00%4100.00%

static const struct block_device_operations nbd_fops = { .owner = THIS_MODULE, .ioctl = nbd_ioctl, .compat_ioctl = nbd_ioctl, }; #if IS_ENABLED(CONFIG_DEBUG_FS)
static int nbd_dbg_tasks_show(struct seq_file *s, void *unused) { struct nbd_device *nbd = s->private; if (nbd->task_recv) seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv)); if (nbd->task_send) seq_printf(s, "send: %d\n", task_pid_nr(nbd->task_send)); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann4567.16%112.50%
sven wegenersven wegener913.43%112.50%
pre-gitpre-git913.43%225.00%
laurent vivierlaurent vivier11.49%112.50%
adrian bunkadrian bunk11.49%112.50%
linus torvaldslinus torvalds11.49%112.50%
al viroal viro11.49%112.50%
Total67100.00%8100.00%


static int nbd_dbg_tasks_open(struct inode *inode, struct file *file) { return single_open(file, nbd_dbg_tasks_show, inode->i_private); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann2796.43%150.00%
namhyung kimnamhyung kim13.57%150.00%
Total28100.00%2100.00%

static const struct file_operations nbd_dbg_tasks_ops = { .open = nbd_dbg_tasks_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, };
static int nbd_dbg_flags_show(struct seq_file *s, void *unused) { struct nbd_device *nbd = s->private; u32 flags = nbd->flags; seq_printf(s, "Hex: 0x%08x\n\n", flags); seq_puts(s, "Known flags:\n"); if (flags & NBD_FLAG_HAS_FLAGS) seq_puts(s, "NBD_FLAG_HAS_FLAGS\n"); if (flags & NBD_FLAG_READ_ONLY) seq_puts(s, "NBD_FLAG_READ_ONLY\n"); if (flags & NBD_FLAG_SEND_FLUSH) seq_puts(s, "NBD_FLAG_SEND_FLUSH\n"); if (flags & NBD_FLAG_SEND_TRIM) seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann8987.25%120.00%
sudip mukherjeesudip mukherjee65.88%120.00%
namhyung kimnamhyung kim43.92%240.00%
laurent vivierlaurent vivier32.94%120.00%
Total102100.00%5100.00%


static int nbd_dbg_flags_open(struct inode *inode, struct file *file) { return single_open(file, nbd_dbg_flags_show, inode->i_private); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann28100.00%1100.00%
Total28100.00%1100.00%

static const struct file_operations nbd_dbg_flags_ops = { .open = nbd_dbg_flags_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, };
static int nbd_dev_dbg_init(struct nbd_device *nbd) { struct dentry *dir; if (!nbd_dbg_dir) return -EIO; dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); if (!dir) { dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n", nbd_name(nbd)); return -EIO; } nbd->dbg_dir = dir; debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout); debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize); debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann142100.00%2100.00%
Total142100.00%2100.00%


static void nbd_dev_dbg_close(struct nbd_device *nbd) { debugfs_remove_recursive(nbd->dbg_dir); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann18100.00%1100.00%
Total18100.00%1100.00%


static int nbd_dbg_init(void) { struct dentry *dbg_dir; dbg_dir = debugfs_create_dir("nbd", NULL); if (!dbg_dir) return -EIO; nbd_dbg_dir = dbg_dir; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann38100.00%2100.00%
Total38100.00%2100.00%


static void nbd_dbg_close(void) { debugfs_remove_recursive(nbd_dbg_dir); }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann13100.00%1100.00%
Total13100.00%1100.00%

#else /* IS_ENABLED(CONFIG_DEBUG_FS) */
static int nbd_dev_dbg_init(struct nbd_device *nbd) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann14100.00%1100.00%
Total14100.00%1100.00%


static void nbd_dev_dbg_close(struct nbd_device *nbd) { }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann10100.00%1100.00%
Total10100.00%1100.00%


static int nbd_dbg_init(void) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann11100.00%1100.00%
Total11100.00%1100.00%


static void nbd_dbg_close(void) { }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann7100.00%1100.00%
Total7100.00%1100.00%

#endif /* * And here should be modules and kernel interface * (Just smiley confuses emacs :-) */
static int __init nbd_init(void) { int err = -ENOMEM; int i; int part_shift; BUILD_BUG_ON(sizeof(struct nbd_request) != 28); if (max_part < 0) { printk(KERN_ERR "nbd: max_part must be >= 0\n"); return -EINVAL; } part_shift = 0; if (max_part > 0) { part_shift = fls(max_part); /* * Adjust max_part according to part_shift as it is exported * to user space so that user can know the max number of * partition kernel should be able to manage. * * Note that -1 is required because partition 0 is reserved * for the whole disk. */ max_part = (1UL << part_shift) - 1; } if ((1UL << part_shift) > DISK_MAX_PARTS) return -EINVAL; if (nbds_max > 1UL << (MINORBITS - part_shift)) return -EINVAL; nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); if (!nbd_dev) return -ENOMEM; for (i = 0; i < nbds_max; i++) { struct gendisk *disk = alloc_disk(1 << part_shift); if (!disk) goto out; nbd_dev[i].disk = disk; /* * The new linux 2.5 block layer implementation requires * every gendisk to have its very own request_queue struct. * These structs are big so we dynamically allocate them. */ disk->queue = blk_init_queue(nbd_request_handler, &nbd_lock); if (!disk->queue) { put_disk(disk); goto out; } /* * Tell the block layer that we are not a rotational device */ queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue); disk->queue->limits.discard_granularity = 512; blk_queue_max_discard_sectors(disk->queue, UINT_MAX); disk->queue->limits.discard_zeroes_data = 0; blk_queue_max_hw_sectors(disk->queue, 65536); disk->queue->limits.max_sectors = 256; } if (register_blkdev(NBD_MAJOR, "nbd")) { err = -EIO; goto out; } printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); nbd_dbg_init(); for (i = 0; i < nbds_max; i++) { struct gendisk *disk = nbd_dev[i].disk; nbd_dev[i].magic = NBD_MAGIC; INIT_LIST_HEAD(&nbd_dev[i].waiting_queue); spin_lock_init(&nbd_dev[i].queue_lock); spin_lock_init(&nbd_dev[i].sock_lock); INIT_LIST_HEAD(&nbd_dev[i].queue_head); mutex_init(&nbd_dev[i].tx_lock); init_timer(&nbd_dev[i].timeout_timer); nbd_dev[i].timeout_timer.function = nbd_xmit_timeout; nbd_dev[i].timeout_timer.data = (unsigned long)&nbd_dev[i]; init_waitqueue_head(&nbd_dev[i].active_wq); init_waitqueue_head(&nbd_dev[i].waiting_wq); disk->major = NBD_MAJOR; disk->first_minor = i << part_shift; disk->fops = &nbd_fops; disk->private_data = &nbd_dev[i]; sprintf(disk->disk_name, "nbd%d", i); nbd_reset(&nbd_dev[i]); add_disk(disk); } return 0; out: while (i--) { blk_cleanup_queue(nbd_dev[i].disk->queue); put_disk(nbd_dev[i].disk); } kfree(nbd_dev); return err; }

Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann19034.11%615.38%
al viroal viro11420.47%615.38%
pre-gitpre-git7112.75%615.38%
lou langholtzlou langholtz397.00%12.56%
paul clementspaul clements335.92%25.13%
laurent vivierlaurent vivier264.67%25.13%
michal belczykmichal belczyk193.41%12.56%
herbert xuherbert xu111.97%12.56%
dave jonesdave jones111.97%12.56%
jens axboejens axboe111.97%37.69%
mike snitzermike snitzer91.62%12.56%
christoph hellwigchristoph hellwig71.26%25.13%
sudip mukherjeesudip mukherjee50.90%12.56%
sven wegenersven wegener50.90%12.56%
lars marowsky-breelars marowsky-bree20.36%12.56%
anton altaparmakovanton altaparmakov10.18%12.56%
wanlong gaowanlong gao10.18%12.56%
andrew mortonandrew morton10.18%12.56%
ingo molnaringo molnar10.18%12.56%
Total557100.00%39100.00%


static void __exit nbd_cleanup(void) { int i; nbd_dbg_close(); for (i = 0; i < nbds_max; i++) { struct gendisk *disk = nbd_dev[i].disk; nbd_dev[i].magic = 0; if (disk) { del_gendisk(disk); blk_cleanup_queue(disk->queue); put_disk(disk); } } unregister_blkdev(NBD_MAJOR, "nbd"); kfree(nbd_dev); printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); }

Contributors

PersonTokensPropCommitsCommitProp
lou langholtzlou langholtz2728.72%17.69%
al viroal viro2425.53%215.38%
pre-gitpre-git1617.02%323.08%
lars marowsky-breelars marowsky-bree1010.64%17.69%
sven wegenersven wegener55.32%17.69%
andrew mortonandrew morton55.32%215.38%
markus pargmannmarkus pargmann33.19%17.69%
linus torvaldslinus torvalds33.19%17.69%
christoph hellwigchristoph hellwig11.06%17.69%
Total94100.00%13100.00%

module_init(nbd_init); module_exit(nbd_cleanup); MODULE_DESCRIPTION("Network Block Device"); MODULE_LICENSE("GPL"); module_param(nbds_max, int, 0444); MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); module_param(max_part, int, 0444); MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)");

Overall Contributors

PersonTokensPropCommitsCommitProp
markus pargmannmarkus pargmann181235.27%2314.56%
pre-gitpre-git73614.33%1912.03%
paul clementspaul clements3216.25%106.33%
laurent vivierlaurent vivier3005.84%21.27%
andrew mortonandrew morton2384.63%95.70%
lou langholtzlou langholtz1943.78%10.63%
al viroal viro1833.56%116.96%
pavel machekpavel machek1472.86%53.16%
christoph hellwigchristoph hellwig1382.69%53.16%
wanlong gaowanlong gao1252.43%10.63%
herbert xuherbert xu1232.39%10.63%
americo wangamerico wang1212.36%42.53%
dave jonesdave jones1082.10%21.27%
linus torvaldslinus torvalds1082.10%95.70%
paolo bonzinipaolo bonzini450.88%21.27%
michal feixmichal feix390.76%21.27%
mike snitzermike snitzer360.70%21.27%
alan coxalan cox360.70%10.63%
mel gormanmel gorman340.66%10.63%
lars marowsky-breelars marowsky-bree340.66%10.63%
jens axboejens axboe240.47%74.43%
tejun heotejun heo200.39%53.16%
michal belczykmichal belczyk190.37%10.63%
kay sieverskay sievers190.37%10.63%
sven wegenersven wegener190.37%10.63%
neil brownneil brown170.33%10.63%
hani benhabileshani benhabiles170.33%10.63%
cheng renquancheng renquan160.31%21.27%
alex blighalex bligh140.27%10.63%
alex elderalex elder120.23%10.63%
sudip mukherjeesudip mukherjee110.21%10.63%
arnd bergmannarnd bergmann100.19%31.90%
namhyung kimnamhyung kim80.16%31.90%
fujita tomonorifujita tomonori80.16%10.63%
kiyoshi uedakiyoshi ueda70.14%10.63%
trond myklebusttrond myklebust50.10%10.63%
kent overstreetkent overstreet50.10%21.27%
ingo molnaringo molnar40.08%10.63%
thomas gleixnerthomas gleixner40.08%10.63%
rusty russellrusty russell40.08%10.63%
adrian bunkadrian bunk40.08%21.27%
arnaldo carvalho de meloarnaldo carvalho de melo30.06%10.63%
kees cookkees cook20.04%10.63%
david s. millerdavid s. miller20.04%21.27%
chetan lokechetan loke10.02%10.63%
dongsheng yangdongsheng yang10.02%10.63%
dan streetmandan streetman10.02%10.63%
anton altaparmakovanton altaparmakov10.02%10.63%
alexey dobriyanalexey dobriyan10.02%10.63%
Total5137100.00%158100.00%
Directory: drivers/block
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{% endraw %}