6e60a3bbb4
Christoph made it so that if we return'ed BLK_STS_RESOURCE whenever we
got ERESTARTSYS from sending our packets we'd return BLK_STS_OK, which
means we'd never requeue and just hang. We really need to return the
right value from the upper layer.
Fixes: fc17b6534e
("blk-mq: switch ->queue_rq return value to blk_status_t")
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2160 lines
53 KiB
C
2160 lines
53 KiB
C
/*
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* Network block device - make block devices work over TCP
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*
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* Note that you can not swap over this thing, yet. Seems to work but
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* deadlocks sometimes - you can not swap over TCP in general.
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*
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* Copyright 1997-2000, 2008 Pavel Machek <pavel@ucw.cz>
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* Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com>
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*
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* This file is released under GPLv2 or later.
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*
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* (part of code stolen from loop.c)
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*/
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#include <linux/major.h>
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|
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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/sched/mm.h>
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#include <linux/fs.h>
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#include <linux/bio.h>
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#include <linux/stat.h>
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#include <linux/errno.h>
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#include <linux/file.h>
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#include <linux/ioctl.h>
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#include <linux/mutex.h>
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#include <linux/compiler.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <net/sock.h>
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#include <linux/net.h>
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#include <linux/kthread.h>
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#include <linux/types.h>
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#include <linux/debugfs.h>
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#include <linux/blk-mq.h>
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#include <linux/uaccess.h>
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#include <asm/types.h>
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#include <linux/nbd.h>
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#include <linux/nbd-netlink.h>
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#include <net/genetlink.h>
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static DEFINE_IDR(nbd_index_idr);
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static DEFINE_MUTEX(nbd_index_mutex);
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static int nbd_total_devices = 0;
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struct nbd_sock {
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struct socket *sock;
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struct mutex tx_lock;
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struct request *pending;
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int sent;
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bool dead;
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int fallback_index;
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int cookie;
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};
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struct recv_thread_args {
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struct work_struct work;
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struct nbd_device *nbd;
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int index;
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};
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struct link_dead_args {
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struct work_struct work;
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int index;
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};
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#define NBD_TIMEDOUT 0
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#define NBD_DISCONNECT_REQUESTED 1
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#define NBD_DISCONNECTED 2
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#define NBD_HAS_PID_FILE 3
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#define NBD_HAS_CONFIG_REF 4
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#define NBD_BOUND 5
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#define NBD_DESTROY_ON_DISCONNECT 6
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struct nbd_config {
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u32 flags;
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unsigned long runtime_flags;
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u64 dead_conn_timeout;
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|
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struct nbd_sock **socks;
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int num_connections;
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atomic_t live_connections;
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wait_queue_head_t conn_wait;
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atomic_t recv_threads;
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wait_queue_head_t recv_wq;
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loff_t blksize;
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loff_t bytesize;
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#if IS_ENABLED(CONFIG_DEBUG_FS)
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struct dentry *dbg_dir;
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#endif
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};
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struct nbd_device {
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struct blk_mq_tag_set tag_set;
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int index;
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refcount_t config_refs;
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refcount_t refs;
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struct nbd_config *config;
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struct mutex config_lock;
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struct gendisk *disk;
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|
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struct list_head list;
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struct task_struct *task_recv;
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struct task_struct *task_setup;
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};
|
|
|
|
struct nbd_cmd {
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struct nbd_device *nbd;
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int index;
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int cookie;
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struct completion send_complete;
|
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blk_status_t status;
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};
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|
|
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#if IS_ENABLED(CONFIG_DEBUG_FS)
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static struct dentry *nbd_dbg_dir;
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#endif
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|
|
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#define nbd_name(nbd) ((nbd)->disk->disk_name)
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|
|
#define NBD_MAGIC 0x68797548
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|
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static unsigned int nbds_max = 16;
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static int max_part = 16;
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static struct workqueue_struct *recv_workqueue;
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static int part_shift;
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static int nbd_dev_dbg_init(struct nbd_device *nbd);
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static void nbd_dev_dbg_close(struct nbd_device *nbd);
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static void nbd_config_put(struct nbd_device *nbd);
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static void nbd_connect_reply(struct genl_info *info, int index);
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static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info);
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static void nbd_dead_link_work(struct work_struct *work);
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static inline struct device *nbd_to_dev(struct nbd_device *nbd)
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{
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return disk_to_dev(nbd->disk);
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}
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|
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|
static const char *nbdcmd_to_ascii(int cmd)
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|
{
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switch (cmd) {
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case NBD_CMD_READ: return "read";
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case NBD_CMD_WRITE: return "write";
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case NBD_CMD_DISC: return "disconnect";
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case NBD_CMD_FLUSH: return "flush";
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case NBD_CMD_TRIM: return "trim/discard";
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}
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return "invalid";
|
|
}
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|
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|
static ssize_t pid_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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|
{
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struct gendisk *disk = dev_to_disk(dev);
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struct nbd_device *nbd = (struct nbd_device *)disk->private_data;
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return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv));
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}
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|
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static const struct device_attribute pid_attr = {
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.attr = { .name = "pid", .mode = S_IRUGO},
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.show = pid_show,
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};
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static void nbd_dev_remove(struct nbd_device *nbd)
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{
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struct gendisk *disk = nbd->disk;
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if (disk) {
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del_gendisk(disk);
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blk_cleanup_queue(disk->queue);
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blk_mq_free_tag_set(&nbd->tag_set);
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disk->private_data = NULL;
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put_disk(disk);
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}
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kfree(nbd);
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}
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static void nbd_put(struct nbd_device *nbd)
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{
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if (refcount_dec_and_mutex_lock(&nbd->refs,
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&nbd_index_mutex)) {
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idr_remove(&nbd_index_idr, nbd->index);
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mutex_unlock(&nbd_index_mutex);
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nbd_dev_remove(nbd);
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}
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}
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static int nbd_disconnected(struct nbd_config *config)
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{
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return test_bit(NBD_DISCONNECTED, &config->runtime_flags) ||
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test_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags);
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}
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static void nbd_mark_nsock_dead(struct nbd_device *nbd, struct nbd_sock *nsock,
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int notify)
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{
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|
if (!nsock->dead && notify && !nbd_disconnected(nbd->config)) {
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struct link_dead_args *args;
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args = kmalloc(sizeof(struct link_dead_args), GFP_NOIO);
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if (args) {
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|
INIT_WORK(&args->work, nbd_dead_link_work);
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args->index = nbd->index;
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queue_work(system_wq, &args->work);
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}
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}
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if (!nsock->dead) {
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kernel_sock_shutdown(nsock->sock, SHUT_RDWR);
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atomic_dec(&nbd->config->live_connections);
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}
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nsock->dead = true;
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nsock->pending = NULL;
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nsock->sent = 0;
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}
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|
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|
static void nbd_size_clear(struct nbd_device *nbd)
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{
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if (nbd->config->bytesize) {
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set_capacity(nbd->disk, 0);
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kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
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}
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}
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static void nbd_size_update(struct nbd_device *nbd)
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{
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struct nbd_config *config = nbd->config;
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blk_queue_logical_block_size(nbd->disk->queue, config->blksize);
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blk_queue_physical_block_size(nbd->disk->queue, config->blksize);
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set_capacity(nbd->disk, config->bytesize >> 9);
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kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
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}
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static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize,
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loff_t nr_blocks)
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|
{
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|
struct nbd_config *config = nbd->config;
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config->blksize = blocksize;
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config->bytesize = blocksize * nr_blocks;
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nbd_size_update(nbd);
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}
|
|
|
|
static void nbd_complete_rq(struct request *req)
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|
{
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|
struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
|
|
|
|
dev_dbg(nbd_to_dev(cmd->nbd), "request %p: %s\n", cmd,
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cmd->status ? "failed" : "done");
|
|
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|
blk_mq_end_request(req, cmd->status);
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}
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|
/*
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|
* Forcibly shutdown the socket causing all listeners to error
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*/
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static void sock_shutdown(struct nbd_device *nbd)
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|
{
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|
struct nbd_config *config = nbd->config;
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int i;
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|
if (config->num_connections == 0)
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return;
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if (test_and_set_bit(NBD_DISCONNECTED, &config->runtime_flags))
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return;
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for (i = 0; i < config->num_connections; i++) {
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struct nbd_sock *nsock = config->socks[i];
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mutex_lock(&nsock->tx_lock);
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nbd_mark_nsock_dead(nbd, nsock, 0);
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mutex_unlock(&nsock->tx_lock);
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}
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dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n");
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}
|
|
|
|
static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
|
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bool reserved)
|
|
{
|
|
struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
|
|
struct nbd_device *nbd = cmd->nbd;
|
|
struct nbd_config *config;
|
|
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|
if (!refcount_inc_not_zero(&nbd->config_refs)) {
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cmd->status = BLK_STS_TIMEOUT;
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|
return BLK_EH_HANDLED;
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|
}
|
|
|
|
/* If we are waiting on our dead timer then we could get timeout
|
|
* callbacks for our request. For this we just want to reset the timer
|
|
* and let the queue side take care of everything.
|
|
*/
|
|
if (!completion_done(&cmd->send_complete)) {
|
|
nbd_config_put(nbd);
|
|
return BLK_EH_RESET_TIMER;
|
|
}
|
|
config = nbd->config;
|
|
|
|
if (config->num_connections > 1) {
|
|
dev_err_ratelimited(nbd_to_dev(nbd),
|
|
"Connection timed out, retrying\n");
|
|
/*
|
|
* Hooray we have more connections, requeue this IO, the submit
|
|
* path will put it on a real connection.
|
|
*/
|
|
if (config->socks && config->num_connections > 1) {
|
|
if (cmd->index < config->num_connections) {
|
|
struct nbd_sock *nsock =
|
|
config->socks[cmd->index];
|
|
mutex_lock(&nsock->tx_lock);
|
|
/* We can have multiple outstanding requests, so
|
|
* we don't want to mark the nsock dead if we've
|
|
* already reconnected with a new socket, so
|
|
* only mark it dead if its the same socket we
|
|
* were sent out on.
|
|
*/
|
|
if (cmd->cookie == nsock->cookie)
|
|
nbd_mark_nsock_dead(nbd, nsock, 1);
|
|
mutex_unlock(&nsock->tx_lock);
|
|
}
|
|
blk_mq_requeue_request(req, true);
|
|
nbd_config_put(nbd);
|
|
return BLK_EH_NOT_HANDLED;
|
|
}
|
|
} else {
|
|
dev_err_ratelimited(nbd_to_dev(nbd),
|
|
"Connection timed out\n");
|
|
}
|
|
set_bit(NBD_TIMEDOUT, &config->runtime_flags);
|
|
cmd->status = BLK_STS_IOERR;
|
|
sock_shutdown(nbd);
|
|
nbd_config_put(nbd);
|
|
|
|
return BLK_EH_HANDLED;
|
|
}
|
|
|
|
/*
|
|
* Send or receive packet.
|
|
*/
|
|
static int sock_xmit(struct nbd_device *nbd, int index, int send,
|
|
struct iov_iter *iter, int msg_flags, int *sent)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
struct socket *sock = config->socks[index]->sock;
|
|
int result;
|
|
struct msghdr msg;
|
|
unsigned int noreclaim_flag;
|
|
|
|
if (unlikely(!sock)) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Attempted %s on closed socket in sock_xmit\n",
|
|
(send ? "send" : "recv"));
|
|
return -EINVAL;
|
|
}
|
|
|
|
msg.msg_iter = *iter;
|
|
|
|
noreclaim_flag = memalloc_noreclaim_save();
|
|
do {
|
|
sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
|
|
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 = sock_sendmsg(sock, &msg);
|
|
else
|
|
result = sock_recvmsg(sock, &msg, msg.msg_flags);
|
|
|
|
if (result <= 0) {
|
|
if (result == 0)
|
|
result = -EPIPE; /* short read */
|
|
break;
|
|
}
|
|
if (sent)
|
|
*sent += result;
|
|
} while (msg_data_left(&msg));
|
|
|
|
memalloc_noreclaim_restore(noreclaim_flag);
|
|
|
|
return result;
|
|
}
|
|
|
|
/* always call with the tx_lock held */
|
|
static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
|
|
{
|
|
struct request *req = blk_mq_rq_from_pdu(cmd);
|
|
struct nbd_config *config = nbd->config;
|
|
struct nbd_sock *nsock = config->socks[index];
|
|
int result;
|
|
struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)};
|
|
struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};
|
|
struct iov_iter from;
|
|
unsigned long size = blk_rq_bytes(req);
|
|
struct bio *bio;
|
|
u32 type;
|
|
u32 nbd_cmd_flags = 0;
|
|
u32 tag = blk_mq_unique_tag(req);
|
|
int sent = nsock->sent, skip = 0;
|
|
|
|
iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));
|
|
|
|
switch (req_op(req)) {
|
|
case REQ_OP_DISCARD:
|
|
type = NBD_CMD_TRIM;
|
|
break;
|
|
case REQ_OP_FLUSH:
|
|
type = NBD_CMD_FLUSH;
|
|
break;
|
|
case REQ_OP_WRITE:
|
|
type = NBD_CMD_WRITE;
|
|
break;
|
|
case REQ_OP_READ:
|
|
type = NBD_CMD_READ;
|
|
break;
|
|
default:
|
|
return -EIO;
|
|
}
|
|
|
|
if (rq_data_dir(req) == WRITE &&
|
|
(config->flags & NBD_FLAG_READ_ONLY)) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Write on read-only\n");
|
|
return -EIO;
|
|
}
|
|
|
|
if (req->cmd_flags & REQ_FUA)
|
|
nbd_cmd_flags |= NBD_CMD_FLAG_FUA;
|
|
|
|
/* We did a partial send previously, and we at least sent the whole
|
|
* request struct, so just go and send the rest of the pages in the
|
|
* request.
|
|
*/
|
|
if (sent) {
|
|
if (sent >= sizeof(request)) {
|
|
skip = sent - sizeof(request);
|
|
goto send_pages;
|
|
}
|
|
iov_iter_advance(&from, sent);
|
|
}
|
|
cmd->index = index;
|
|
cmd->cookie = nsock->cookie;
|
|
request.type = htonl(type | nbd_cmd_flags);
|
|
if (type != NBD_CMD_FLUSH) {
|
|
request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
|
|
request.len = htonl(size);
|
|
}
|
|
memcpy(request.handle, &tag, sizeof(tag));
|
|
|
|
dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",
|
|
cmd, nbdcmd_to_ascii(type),
|
|
(unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
|
|
result = sock_xmit(nbd, index, 1, &from,
|
|
(type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent);
|
|
if (result <= 0) {
|
|
if (result == -ERESTARTSYS) {
|
|
/* If we havne't sent anything we can just return BUSY,
|
|
* however if we have sent something we need to make
|
|
* sure we only allow this req to be sent until we are
|
|
* completely done.
|
|
*/
|
|
if (sent) {
|
|
nsock->pending = req;
|
|
nsock->sent = sent;
|
|
}
|
|
return BLK_STS_RESOURCE;
|
|
}
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Send control failed (result %d)\n", result);
|
|
return -EAGAIN;
|
|
}
|
|
send_pages:
|
|
if (type != NBD_CMD_WRITE)
|
|
goto out;
|
|
|
|
bio = req->bio;
|
|
while (bio) {
|
|
struct bio *next = bio->bi_next;
|
|
struct bvec_iter iter;
|
|
struct bio_vec bvec;
|
|
|
|
bio_for_each_segment(bvec, bio, iter) {
|
|
bool is_last = !next && bio_iter_last(bvec, iter);
|
|
int flags = is_last ? 0 : MSG_MORE;
|
|
|
|
dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
|
|
cmd, bvec.bv_len);
|
|
iov_iter_bvec(&from, ITER_BVEC | WRITE,
|
|
&bvec, 1, bvec.bv_len);
|
|
if (skip) {
|
|
if (skip >= iov_iter_count(&from)) {
|
|
skip -= iov_iter_count(&from);
|
|
continue;
|
|
}
|
|
iov_iter_advance(&from, skip);
|
|
skip = 0;
|
|
}
|
|
result = sock_xmit(nbd, index, 1, &from, flags, &sent);
|
|
if (result <= 0) {
|
|
if (result == -ERESTARTSYS) {
|
|
/* We've already sent the header, we
|
|
* have no choice but to set pending and
|
|
* return BUSY.
|
|
*/
|
|
nsock->pending = req;
|
|
nsock->sent = sent;
|
|
return BLK_STS_RESOURCE;
|
|
}
|
|
dev_err(disk_to_dev(nbd->disk),
|
|
"Send data failed (result %d)\n",
|
|
result);
|
|
return -EAGAIN;
|
|
}
|
|
/*
|
|
* The completion might already have come in,
|
|
* so break for the last one instead of letting
|
|
* the iterator do it. This prevents use-after-free
|
|
* of the bio.
|
|
*/
|
|
if (is_last)
|
|
break;
|
|
}
|
|
bio = next;
|
|
}
|
|
out:
|
|
nsock->pending = NULL;
|
|
nsock->sent = 0;
|
|
return 0;
|
|
}
|
|
|
|
/* NULL returned = something went wrong, inform userspace */
|
|
static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
int result;
|
|
struct nbd_reply reply;
|
|
struct nbd_cmd *cmd;
|
|
struct request *req = NULL;
|
|
u16 hwq;
|
|
u32 tag;
|
|
struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)};
|
|
struct iov_iter to;
|
|
|
|
reply.magic = 0;
|
|
iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply));
|
|
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
|
|
if (result <= 0) {
|
|
if (!nbd_disconnected(config))
|
|
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);
|
|
}
|
|
|
|
memcpy(&tag, reply.handle, sizeof(u32));
|
|
|
|
hwq = blk_mq_unique_tag_to_hwq(tag);
|
|
if (hwq < nbd->tag_set.nr_hw_queues)
|
|
req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq],
|
|
blk_mq_unique_tag_to_tag(tag));
|
|
if (!req || !blk_mq_request_started(req)) {
|
|
dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n",
|
|
tag, req);
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
cmd = blk_mq_rq_to_pdu(req);
|
|
if (ntohl(reply.error)) {
|
|
dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
|
|
ntohl(reply.error));
|
|
cmd->status = BLK_STS_IOERR;
|
|
return cmd;
|
|
}
|
|
|
|
dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd);
|
|
if (rq_data_dir(req) != WRITE) {
|
|
struct req_iterator iter;
|
|
struct bio_vec bvec;
|
|
|
|
rq_for_each_segment(bvec, req, iter) {
|
|
iov_iter_bvec(&to, ITER_BVEC | READ,
|
|
&bvec, 1, bvec.bv_len);
|
|
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
|
|
if (result <= 0) {
|
|
dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
|
|
result);
|
|
/*
|
|
* If we've disconnected or we only have 1
|
|
* connection then we need to make sure we
|
|
* complete this request, otherwise error out
|
|
* and let the timeout stuff handle resubmitting
|
|
* this request onto another connection.
|
|
*/
|
|
if (nbd_disconnected(config) ||
|
|
config->num_connections <= 1) {
|
|
cmd->status = BLK_STS_IOERR;
|
|
return cmd;
|
|
}
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
|
|
cmd, bvec.bv_len);
|
|
}
|
|
} else {
|
|
/* See the comment in nbd_queue_rq. */
|
|
wait_for_completion(&cmd->send_complete);
|
|
}
|
|
return cmd;
|
|
}
|
|
|
|
static void recv_work(struct work_struct *work)
|
|
{
|
|
struct recv_thread_args *args = container_of(work,
|
|
struct recv_thread_args,
|
|
work);
|
|
struct nbd_device *nbd = args->nbd;
|
|
struct nbd_config *config = nbd->config;
|
|
struct nbd_cmd *cmd;
|
|
|
|
while (1) {
|
|
cmd = nbd_read_stat(nbd, args->index);
|
|
if (IS_ERR(cmd)) {
|
|
struct nbd_sock *nsock = config->socks[args->index];
|
|
|
|
mutex_lock(&nsock->tx_lock);
|
|
nbd_mark_nsock_dead(nbd, nsock, 1);
|
|
mutex_unlock(&nsock->tx_lock);
|
|
break;
|
|
}
|
|
|
|
blk_mq_complete_request(blk_mq_rq_from_pdu(cmd));
|
|
}
|
|
atomic_dec(&config->recv_threads);
|
|
wake_up(&config->recv_wq);
|
|
nbd_config_put(nbd);
|
|
kfree(args);
|
|
}
|
|
|
|
static void nbd_clear_req(struct request *req, void *data, bool reserved)
|
|
{
|
|
struct nbd_cmd *cmd;
|
|
|
|
if (!blk_mq_request_started(req))
|
|
return;
|
|
cmd = blk_mq_rq_to_pdu(req);
|
|
cmd->status = BLK_STS_IOERR;
|
|
blk_mq_complete_request(req);
|
|
}
|
|
|
|
static void nbd_clear_que(struct nbd_device *nbd)
|
|
{
|
|
blk_mq_quiesce_queue(nbd->disk->queue);
|
|
blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL);
|
|
blk_mq_unquiesce_queue(nbd->disk->queue);
|
|
dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n");
|
|
}
|
|
|
|
static int find_fallback(struct nbd_device *nbd, int index)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
int new_index = -1;
|
|
struct nbd_sock *nsock = config->socks[index];
|
|
int fallback = nsock->fallback_index;
|
|
|
|
if (test_bit(NBD_DISCONNECTED, &config->runtime_flags))
|
|
return new_index;
|
|
|
|
if (config->num_connections <= 1) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Attempted send on invalid socket\n");
|
|
return new_index;
|
|
}
|
|
|
|
if (fallback >= 0 && fallback < config->num_connections &&
|
|
!config->socks[fallback]->dead)
|
|
return fallback;
|
|
|
|
if (nsock->fallback_index < 0 ||
|
|
nsock->fallback_index >= config->num_connections ||
|
|
config->socks[nsock->fallback_index]->dead) {
|
|
int i;
|
|
for (i = 0; i < config->num_connections; i++) {
|
|
if (i == index)
|
|
continue;
|
|
if (!config->socks[i]->dead) {
|
|
new_index = i;
|
|
break;
|
|
}
|
|
}
|
|
nsock->fallback_index = new_index;
|
|
if (new_index < 0) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Dead connection, failed to find a fallback\n");
|
|
return new_index;
|
|
}
|
|
}
|
|
new_index = nsock->fallback_index;
|
|
return new_index;
|
|
}
|
|
|
|
static int wait_for_reconnect(struct nbd_device *nbd)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
if (!config->dead_conn_timeout)
|
|
return 0;
|
|
if (test_bit(NBD_DISCONNECTED, &config->runtime_flags))
|
|
return 0;
|
|
wait_event_interruptible_timeout(config->conn_wait,
|
|
atomic_read(&config->live_connections),
|
|
config->dead_conn_timeout);
|
|
return atomic_read(&config->live_connections);
|
|
}
|
|
|
|
static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
|
|
{
|
|
struct request *req = blk_mq_rq_from_pdu(cmd);
|
|
struct nbd_device *nbd = cmd->nbd;
|
|
struct nbd_config *config;
|
|
struct nbd_sock *nsock;
|
|
int ret;
|
|
|
|
if (!refcount_inc_not_zero(&nbd->config_refs)) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Socks array is empty\n");
|
|
return -EINVAL;
|
|
}
|
|
config = nbd->config;
|
|
|
|
if (index >= config->num_connections) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Attempted send on invalid socket\n");
|
|
nbd_config_put(nbd);
|
|
return -EINVAL;
|
|
}
|
|
cmd->status = BLK_STS_OK;
|
|
again:
|
|
nsock = config->socks[index];
|
|
mutex_lock(&nsock->tx_lock);
|
|
if (nsock->dead) {
|
|
int old_index = index;
|
|
index = find_fallback(nbd, index);
|
|
mutex_unlock(&nsock->tx_lock);
|
|
if (index < 0) {
|
|
if (wait_for_reconnect(nbd)) {
|
|
index = old_index;
|
|
goto again;
|
|
}
|
|
/* All the sockets should already be down at this point,
|
|
* we just want to make sure that DISCONNECTED is set so
|
|
* any requests that come in that were queue'ed waiting
|
|
* for the reconnect timer don't trigger the timer again
|
|
* and instead just error out.
|
|
*/
|
|
sock_shutdown(nbd);
|
|
nbd_config_put(nbd);
|
|
return -EIO;
|
|
}
|
|
goto again;
|
|
}
|
|
|
|
/* Handle the case that we have a pending request that was partially
|
|
* transmitted that _has_ to be serviced first. We need to call requeue
|
|
* here so that it gets put _after_ the request that is already on the
|
|
* dispatch list.
|
|
*/
|
|
if (unlikely(nsock->pending && nsock->pending != req)) {
|
|
blk_mq_requeue_request(req, true);
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
/*
|
|
* Some failures are related to the link going down, so anything that
|
|
* returns EAGAIN can be retried on a different socket.
|
|
*/
|
|
ret = nbd_send_cmd(nbd, cmd, index);
|
|
if (ret == -EAGAIN) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Request send failed trying another connection\n");
|
|
nbd_mark_nsock_dead(nbd, nsock, 1);
|
|
mutex_unlock(&nsock->tx_lock);
|
|
goto again;
|
|
}
|
|
out:
|
|
mutex_unlock(&nsock->tx_lock);
|
|
nbd_config_put(nbd);
|
|
return ret;
|
|
}
|
|
|
|
static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
|
|
const struct blk_mq_queue_data *bd)
|
|
{
|
|
struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
|
|
int ret;
|
|
|
|
/*
|
|
* Since we look at the bio's to send the request over the network we
|
|
* need to make sure the completion work doesn't mark this request done
|
|
* before we are done doing our send. This keeps us from dereferencing
|
|
* freed data if we have particularly fast completions (ie we get the
|
|
* completion before we exit sock_xmit on the last bvec) or in the case
|
|
* that the server is misbehaving (or there was an error) before we're
|
|
* done sending everything over the wire.
|
|
*/
|
|
init_completion(&cmd->send_complete);
|
|
blk_mq_start_request(bd->rq);
|
|
|
|
/* We can be called directly from the user space process, which means we
|
|
* could possibly have signals pending so our sendmsg will fail. In
|
|
* this case we need to return that we are busy, otherwise error out as
|
|
* appropriate.
|
|
*/
|
|
ret = nbd_handle_cmd(cmd, hctx->queue_num);
|
|
if (ret < 0)
|
|
ret = BLK_STS_IOERR;
|
|
else if (!ret)
|
|
ret = BLK_STS_OK;
|
|
complete(&cmd->send_complete);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
|
|
bool netlink)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
struct socket *sock;
|
|
struct nbd_sock **socks;
|
|
struct nbd_sock *nsock;
|
|
int err;
|
|
|
|
sock = sockfd_lookup(arg, &err);
|
|
if (!sock)
|
|
return err;
|
|
|
|
if (!netlink && !nbd->task_setup &&
|
|
!test_bit(NBD_BOUND, &config->runtime_flags))
|
|
nbd->task_setup = current;
|
|
|
|
if (!netlink &&
|
|
(nbd->task_setup != current ||
|
|
test_bit(NBD_BOUND, &config->runtime_flags))) {
|
|
dev_err(disk_to_dev(nbd->disk),
|
|
"Device being setup by another task");
|
|
sockfd_put(sock);
|
|
return -EBUSY;
|
|
}
|
|
|
|
socks = krealloc(config->socks, (config->num_connections + 1) *
|
|
sizeof(struct nbd_sock *), GFP_KERNEL);
|
|
if (!socks) {
|
|
sockfd_put(sock);
|
|
return -ENOMEM;
|
|
}
|
|
nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL);
|
|
if (!nsock) {
|
|
sockfd_put(sock);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
config->socks = socks;
|
|
|
|
nsock->fallback_index = -1;
|
|
nsock->dead = false;
|
|
mutex_init(&nsock->tx_lock);
|
|
nsock->sock = sock;
|
|
nsock->pending = NULL;
|
|
nsock->sent = 0;
|
|
nsock->cookie = 0;
|
|
socks[config->num_connections++] = nsock;
|
|
atomic_inc(&config->live_connections);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
struct socket *sock, *old;
|
|
struct recv_thread_args *args;
|
|
int i;
|
|
int err;
|
|
|
|
sock = sockfd_lookup(arg, &err);
|
|
if (!sock)
|
|
return err;
|
|
|
|
args = kzalloc(sizeof(*args), GFP_KERNEL);
|
|
if (!args) {
|
|
sockfd_put(sock);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
for (i = 0; i < config->num_connections; i++) {
|
|
struct nbd_sock *nsock = config->socks[i];
|
|
|
|
if (!nsock->dead)
|
|
continue;
|
|
|
|
mutex_lock(&nsock->tx_lock);
|
|
if (!nsock->dead) {
|
|
mutex_unlock(&nsock->tx_lock);
|
|
continue;
|
|
}
|
|
sk_set_memalloc(sock->sk);
|
|
if (nbd->tag_set.timeout)
|
|
sock->sk->sk_sndtimeo = nbd->tag_set.timeout;
|
|
atomic_inc(&config->recv_threads);
|
|
refcount_inc(&nbd->config_refs);
|
|
old = nsock->sock;
|
|
nsock->fallback_index = -1;
|
|
nsock->sock = sock;
|
|
nsock->dead = false;
|
|
INIT_WORK(&args->work, recv_work);
|
|
args->index = i;
|
|
args->nbd = nbd;
|
|
nsock->cookie++;
|
|
mutex_unlock(&nsock->tx_lock);
|
|
sockfd_put(old);
|
|
|
|
clear_bit(NBD_DISCONNECTED, &config->runtime_flags);
|
|
|
|
/* We take the tx_mutex in an error path in the recv_work, so we
|
|
* need to queue_work outside of the tx_mutex.
|
|
*/
|
|
queue_work(recv_workqueue, &args->work);
|
|
|
|
atomic_inc(&config->live_connections);
|
|
wake_up(&config->conn_wait);
|
|
return 0;
|
|
}
|
|
sockfd_put(sock);
|
|
kfree(args);
|
|
return -ENOSPC;
|
|
}
|
|
|
|
static void nbd_bdev_reset(struct block_device *bdev)
|
|
{
|
|
if (bdev->bd_openers > 1)
|
|
return;
|
|
bd_set_size(bdev, 0);
|
|
if (max_part > 0) {
|
|
blkdev_reread_part(bdev);
|
|
bdev->bd_invalidated = 1;
|
|
}
|
|
}
|
|
|
|
static void nbd_parse_flags(struct nbd_device *nbd)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
if (config->flags & NBD_FLAG_READ_ONLY)
|
|
set_disk_ro(nbd->disk, true);
|
|
else
|
|
set_disk_ro(nbd->disk, false);
|
|
if (config->flags & NBD_FLAG_SEND_TRIM)
|
|
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
|
|
if (config->flags & NBD_FLAG_SEND_FLUSH) {
|
|
if (config->flags & NBD_FLAG_SEND_FUA)
|
|
blk_queue_write_cache(nbd->disk->queue, true, true);
|
|
else
|
|
blk_queue_write_cache(nbd->disk->queue, true, false);
|
|
}
|
|
else
|
|
blk_queue_write_cache(nbd->disk->queue, false, false);
|
|
}
|
|
|
|
static void send_disconnects(struct nbd_device *nbd)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
struct nbd_request request = {
|
|
.magic = htonl(NBD_REQUEST_MAGIC),
|
|
.type = htonl(NBD_CMD_DISC),
|
|
};
|
|
struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};
|
|
struct iov_iter from;
|
|
int i, ret;
|
|
|
|
for (i = 0; i < config->num_connections; i++) {
|
|
struct nbd_sock *nsock = config->socks[i];
|
|
|
|
iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));
|
|
mutex_lock(&nsock->tx_lock);
|
|
ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
|
|
if (ret <= 0)
|
|
dev_err(disk_to_dev(nbd->disk),
|
|
"Send disconnect failed %d\n", ret);
|
|
mutex_unlock(&nsock->tx_lock);
|
|
}
|
|
}
|
|
|
|
static int nbd_disconnect(struct nbd_device *nbd)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
|
|
dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n");
|
|
set_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags);
|
|
send_disconnects(nbd);
|
|
return 0;
|
|
}
|
|
|
|
static void nbd_clear_sock(struct nbd_device *nbd)
|
|
{
|
|
sock_shutdown(nbd);
|
|
nbd_clear_que(nbd);
|
|
nbd->task_setup = NULL;
|
|
}
|
|
|
|
static void nbd_config_put(struct nbd_device *nbd)
|
|
{
|
|
if (refcount_dec_and_mutex_lock(&nbd->config_refs,
|
|
&nbd->config_lock)) {
|
|
struct nbd_config *config = nbd->config;
|
|
nbd_dev_dbg_close(nbd);
|
|
nbd_size_clear(nbd);
|
|
if (test_and_clear_bit(NBD_HAS_PID_FILE,
|
|
&config->runtime_flags))
|
|
device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
|
|
nbd->task_recv = NULL;
|
|
nbd_clear_sock(nbd);
|
|
if (config->num_connections) {
|
|
int i;
|
|
for (i = 0; i < config->num_connections; i++) {
|
|
sockfd_put(config->socks[i]->sock);
|
|
kfree(config->socks[i]);
|
|
}
|
|
kfree(config->socks);
|
|
}
|
|
kfree(nbd->config);
|
|
nbd->config = NULL;
|
|
|
|
nbd->tag_set.timeout = 0;
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
|
|
|
|
mutex_unlock(&nbd->config_lock);
|
|
nbd_put(nbd);
|
|
module_put(THIS_MODULE);
|
|
}
|
|
}
|
|
|
|
static int nbd_start_device(struct nbd_device *nbd)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
int num_connections = config->num_connections;
|
|
int error = 0, i;
|
|
|
|
if (nbd->task_recv)
|
|
return -EBUSY;
|
|
if (!config->socks)
|
|
return -EINVAL;
|
|
if (num_connections > 1 &&
|
|
!(config->flags & NBD_FLAG_CAN_MULTI_CONN)) {
|
|
dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections);
|
|
nbd->task_recv = current;
|
|
|
|
nbd_parse_flags(nbd);
|
|
|
|
error = device_create_file(disk_to_dev(nbd->disk), &pid_attr);
|
|
if (error) {
|
|
dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n");
|
|
return error;
|
|
}
|
|
set_bit(NBD_HAS_PID_FILE, &config->runtime_flags);
|
|
|
|
nbd_dev_dbg_init(nbd);
|
|
for (i = 0; i < num_connections; i++) {
|
|
struct recv_thread_args *args;
|
|
|
|
args = kzalloc(sizeof(*args), GFP_KERNEL);
|
|
if (!args) {
|
|
sock_shutdown(nbd);
|
|
return -ENOMEM;
|
|
}
|
|
sk_set_memalloc(config->socks[i]->sock->sk);
|
|
if (nbd->tag_set.timeout)
|
|
config->socks[i]->sock->sk->sk_sndtimeo =
|
|
nbd->tag_set.timeout;
|
|
atomic_inc(&config->recv_threads);
|
|
refcount_inc(&nbd->config_refs);
|
|
INIT_WORK(&args->work, recv_work);
|
|
args->nbd = nbd;
|
|
args->index = i;
|
|
queue_work(recv_workqueue, &args->work);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *bdev)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
int ret;
|
|
|
|
ret = nbd_start_device(nbd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
bd_set_size(bdev, config->bytesize);
|
|
if (max_part)
|
|
bdev->bd_invalidated = 1;
|
|
mutex_unlock(&nbd->config_lock);
|
|
ret = wait_event_interruptible(config->recv_wq,
|
|
atomic_read(&config->recv_threads) == 0);
|
|
if (ret)
|
|
sock_shutdown(nbd);
|
|
mutex_lock(&nbd->config_lock);
|
|
bd_set_size(bdev, 0);
|
|
/* user requested, ignore socket errors */
|
|
if (test_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags))
|
|
ret = 0;
|
|
if (test_bit(NBD_TIMEDOUT, &config->runtime_flags))
|
|
ret = -ETIMEDOUT;
|
|
return ret;
|
|
}
|
|
|
|
static void nbd_clear_sock_ioctl(struct nbd_device *nbd,
|
|
struct block_device *bdev)
|
|
{
|
|
sock_shutdown(nbd);
|
|
kill_bdev(bdev);
|
|
nbd_bdev_reset(bdev);
|
|
if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
|
|
&nbd->config->runtime_flags))
|
|
nbd_config_put(nbd);
|
|
}
|
|
|
|
/* Must be called with config_lock held */
|
|
static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
|
|
switch (cmd) {
|
|
case NBD_DISCONNECT:
|
|
return nbd_disconnect(nbd);
|
|
case NBD_CLEAR_SOCK:
|
|
nbd_clear_sock_ioctl(nbd, bdev);
|
|
return 0;
|
|
case NBD_SET_SOCK:
|
|
return nbd_add_socket(nbd, arg, false);
|
|
case NBD_SET_BLKSIZE:
|
|
nbd_size_set(nbd, arg,
|
|
div_s64(config->bytesize, arg));
|
|
return 0;
|
|
case NBD_SET_SIZE:
|
|
nbd_size_set(nbd, config->blksize,
|
|
div_s64(arg, config->blksize));
|
|
return 0;
|
|
case NBD_SET_SIZE_BLOCKS:
|
|
nbd_size_set(nbd, config->blksize, arg);
|
|
return 0;
|
|
case NBD_SET_TIMEOUT:
|
|
if (arg) {
|
|
nbd->tag_set.timeout = arg * HZ;
|
|
blk_queue_rq_timeout(nbd->disk->queue, arg * HZ);
|
|
}
|
|
return 0;
|
|
|
|
case NBD_SET_FLAGS:
|
|
config->flags = arg;
|
|
return 0;
|
|
case NBD_DO_IT:
|
|
return nbd_start_device_ioctl(nbd, bdev);
|
|
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:
|
|
/*
|
|
* For compatibility only, we no longer keep a list of
|
|
* outstanding requests.
|
|
*/
|
|
return 0;
|
|
}
|
|
return -ENOTTY;
|
|
}
|
|
|
|
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;
|
|
struct nbd_config *config = nbd->config;
|
|
int error = -EINVAL;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
/* The block layer will pass back some non-nbd ioctls in case we have
|
|
* special handling for them, but we don't so just return an error.
|
|
*/
|
|
if (_IOC_TYPE(cmd) != 0xab)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&nbd->config_lock);
|
|
|
|
/* Don't allow ioctl operations on a nbd device that was created with
|
|
* netlink, unless it's DISCONNECT or CLEAR_SOCK, which are fine.
|
|
*/
|
|
if (!test_bit(NBD_BOUND, &config->runtime_flags) ||
|
|
(cmd == NBD_DISCONNECT || cmd == NBD_CLEAR_SOCK))
|
|
error = __nbd_ioctl(bdev, nbd, cmd, arg);
|
|
else
|
|
dev_err(nbd_to_dev(nbd), "Cannot use ioctl interface on a netlink controlled device.\n");
|
|
mutex_unlock(&nbd->config_lock);
|
|
return error;
|
|
}
|
|
|
|
static struct nbd_config *nbd_alloc_config(void)
|
|
{
|
|
struct nbd_config *config;
|
|
|
|
config = kzalloc(sizeof(struct nbd_config), GFP_NOFS);
|
|
if (!config)
|
|
return NULL;
|
|
atomic_set(&config->recv_threads, 0);
|
|
init_waitqueue_head(&config->recv_wq);
|
|
init_waitqueue_head(&config->conn_wait);
|
|
config->blksize = 1024;
|
|
atomic_set(&config->live_connections, 0);
|
|
try_module_get(THIS_MODULE);
|
|
return config;
|
|
}
|
|
|
|
static int nbd_open(struct block_device *bdev, fmode_t mode)
|
|
{
|
|
struct nbd_device *nbd;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&nbd_index_mutex);
|
|
nbd = bdev->bd_disk->private_data;
|
|
if (!nbd) {
|
|
ret = -ENXIO;
|
|
goto out;
|
|
}
|
|
if (!refcount_inc_not_zero(&nbd->refs)) {
|
|
ret = -ENXIO;
|
|
goto out;
|
|
}
|
|
if (!refcount_inc_not_zero(&nbd->config_refs)) {
|
|
struct nbd_config *config;
|
|
|
|
mutex_lock(&nbd->config_lock);
|
|
if (refcount_inc_not_zero(&nbd->config_refs)) {
|
|
mutex_unlock(&nbd->config_lock);
|
|
goto out;
|
|
}
|
|
config = nbd->config = nbd_alloc_config();
|
|
if (!config) {
|
|
ret = -ENOMEM;
|
|
mutex_unlock(&nbd->config_lock);
|
|
goto out;
|
|
}
|
|
refcount_set(&nbd->config_refs, 1);
|
|
refcount_inc(&nbd->refs);
|
|
mutex_unlock(&nbd->config_lock);
|
|
}
|
|
out:
|
|
mutex_unlock(&nbd_index_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static void nbd_release(struct gendisk *disk, fmode_t mode)
|
|
{
|
|
struct nbd_device *nbd = disk->private_data;
|
|
nbd_config_put(nbd);
|
|
nbd_put(nbd);
|
|
}
|
|
|
|
static const struct block_device_operations nbd_fops =
|
|
{
|
|
.owner = THIS_MODULE,
|
|
.open = nbd_open,
|
|
.release = nbd_release,
|
|
.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));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_dbg_tasks_open(struct inode *inode, struct file *file)
|
|
{
|
|
return single_open(file, nbd_dbg_tasks_show, inode->i_private);
|
|
}
|
|
|
|
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->config->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_FUA)
|
|
seq_puts(s, "NBD_FLAG_SEND_FUA\n");
|
|
if (flags & NBD_FLAG_SEND_TRIM)
|
|
seq_puts(s, "NBD_FLAG_SEND_TRIM\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_dbg_flags_open(struct inode *inode, struct file *file)
|
|
{
|
|
return single_open(file, nbd_dbg_flags_show, inode->i_private);
|
|
}
|
|
|
|
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;
|
|
struct nbd_config *config = nbd->config;
|
|
|
|
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;
|
|
}
|
|
config->dbg_dir = dir;
|
|
|
|
debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
|
|
debugfs_create_u64("size_bytes", 0444, dir, &config->bytesize);
|
|
debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout);
|
|
debugfs_create_u64("blocksize", 0444, dir, &config->blksize);
|
|
debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void nbd_dev_dbg_close(struct nbd_device *nbd)
|
|
{
|
|
debugfs_remove_recursive(nbd->config->dbg_dir);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
static void nbd_dbg_close(void)
|
|
{
|
|
debugfs_remove_recursive(nbd_dbg_dir);
|
|
}
|
|
|
|
#else /* IS_ENABLED(CONFIG_DEBUG_FS) */
|
|
|
|
static int nbd_dev_dbg_init(struct nbd_device *nbd)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void nbd_dev_dbg_close(struct nbd_device *nbd)
|
|
{
|
|
}
|
|
|
|
static int nbd_dbg_init(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void nbd_dbg_close(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
static int nbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
|
|
unsigned int hctx_idx, unsigned int numa_node)
|
|
{
|
|
struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq);
|
|
cmd->nbd = set->driver_data;
|
|
return 0;
|
|
}
|
|
|
|
static const struct blk_mq_ops nbd_mq_ops = {
|
|
.queue_rq = nbd_queue_rq,
|
|
.complete = nbd_complete_rq,
|
|
.init_request = nbd_init_request,
|
|
.timeout = nbd_xmit_timeout,
|
|
};
|
|
|
|
static int nbd_dev_add(int index)
|
|
{
|
|
struct nbd_device *nbd;
|
|
struct gendisk *disk;
|
|
struct request_queue *q;
|
|
int err = -ENOMEM;
|
|
|
|
nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL);
|
|
if (!nbd)
|
|
goto out;
|
|
|
|
disk = alloc_disk(1 << part_shift);
|
|
if (!disk)
|
|
goto out_free_nbd;
|
|
|
|
if (index >= 0) {
|
|
err = idr_alloc(&nbd_index_idr, nbd, index, index + 1,
|
|
GFP_KERNEL);
|
|
if (err == -ENOSPC)
|
|
err = -EEXIST;
|
|
} else {
|
|
err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL);
|
|
if (err >= 0)
|
|
index = err;
|
|
}
|
|
if (err < 0)
|
|
goto out_free_disk;
|
|
|
|
nbd->index = index;
|
|
nbd->disk = disk;
|
|
nbd->tag_set.ops = &nbd_mq_ops;
|
|
nbd->tag_set.nr_hw_queues = 1;
|
|
nbd->tag_set.queue_depth = 128;
|
|
nbd->tag_set.numa_node = NUMA_NO_NODE;
|
|
nbd->tag_set.cmd_size = sizeof(struct nbd_cmd);
|
|
nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
|
|
BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING;
|
|
nbd->tag_set.driver_data = nbd;
|
|
|
|
err = blk_mq_alloc_tag_set(&nbd->tag_set);
|
|
if (err)
|
|
goto out_free_idr;
|
|
|
|
q = blk_mq_init_queue(&nbd->tag_set);
|
|
if (IS_ERR(q)) {
|
|
err = PTR_ERR(q);
|
|
goto out_free_tags;
|
|
}
|
|
disk->queue = q;
|
|
|
|
/*
|
|
* 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);
|
|
blk_queue_max_segment_size(disk->queue, UINT_MAX);
|
|
blk_queue_max_segments(disk->queue, USHRT_MAX);
|
|
blk_queue_max_hw_sectors(disk->queue, 65536);
|
|
disk->queue->limits.max_sectors = 256;
|
|
|
|
mutex_init(&nbd->config_lock);
|
|
refcount_set(&nbd->config_refs, 0);
|
|
refcount_set(&nbd->refs, 1);
|
|
INIT_LIST_HEAD(&nbd->list);
|
|
disk->major = NBD_MAJOR;
|
|
disk->first_minor = index << part_shift;
|
|
disk->fops = &nbd_fops;
|
|
disk->private_data = nbd;
|
|
sprintf(disk->disk_name, "nbd%d", index);
|
|
add_disk(disk);
|
|
nbd_total_devices++;
|
|
return index;
|
|
|
|
out_free_tags:
|
|
blk_mq_free_tag_set(&nbd->tag_set);
|
|
out_free_idr:
|
|
idr_remove(&nbd_index_idr, index);
|
|
out_free_disk:
|
|
put_disk(disk);
|
|
out_free_nbd:
|
|
kfree(nbd);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static int find_free_cb(int id, void *ptr, void *data)
|
|
{
|
|
struct nbd_device *nbd = ptr;
|
|
struct nbd_device **found = data;
|
|
|
|
if (!refcount_read(&nbd->config_refs)) {
|
|
*found = nbd;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Netlink interface. */
|
|
static struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = {
|
|
[NBD_ATTR_INDEX] = { .type = NLA_U32 },
|
|
[NBD_ATTR_SIZE_BYTES] = { .type = NLA_U64 },
|
|
[NBD_ATTR_BLOCK_SIZE_BYTES] = { .type = NLA_U64 },
|
|
[NBD_ATTR_TIMEOUT] = { .type = NLA_U64 },
|
|
[NBD_ATTR_SERVER_FLAGS] = { .type = NLA_U64 },
|
|
[NBD_ATTR_CLIENT_FLAGS] = { .type = NLA_U64 },
|
|
[NBD_ATTR_SOCKETS] = { .type = NLA_NESTED},
|
|
[NBD_ATTR_DEAD_CONN_TIMEOUT] = { .type = NLA_U64 },
|
|
[NBD_ATTR_DEVICE_LIST] = { .type = NLA_NESTED},
|
|
};
|
|
|
|
static struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = {
|
|
[NBD_SOCK_FD] = { .type = NLA_U32 },
|
|
};
|
|
|
|
/* We don't use this right now since we don't parse the incoming list, but we
|
|
* still want it here so userspace knows what to expect.
|
|
*/
|
|
static struct nla_policy __attribute__((unused))
|
|
nbd_device_policy[NBD_DEVICE_ATTR_MAX + 1] = {
|
|
[NBD_DEVICE_INDEX] = { .type = NLA_U32 },
|
|
[NBD_DEVICE_CONNECTED] = { .type = NLA_U8 },
|
|
};
|
|
|
|
static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
struct nbd_device *nbd = NULL;
|
|
struct nbd_config *config;
|
|
int index = -1;
|
|
int ret;
|
|
bool put_dev = false;
|
|
|
|
if (!netlink_capable(skb, CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (info->attrs[NBD_ATTR_INDEX])
|
|
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
|
|
if (!info->attrs[NBD_ATTR_SOCKETS]) {
|
|
printk(KERN_ERR "nbd: must specify at least one socket\n");
|
|
return -EINVAL;
|
|
}
|
|
if (!info->attrs[NBD_ATTR_SIZE_BYTES]) {
|
|
printk(KERN_ERR "nbd: must specify a size in bytes for the device\n");
|
|
return -EINVAL;
|
|
}
|
|
again:
|
|
mutex_lock(&nbd_index_mutex);
|
|
if (index == -1) {
|
|
ret = idr_for_each(&nbd_index_idr, &find_free_cb, &nbd);
|
|
if (ret == 0) {
|
|
int new_index;
|
|
new_index = nbd_dev_add(-1);
|
|
if (new_index < 0) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
printk(KERN_ERR "nbd: failed to add new device\n");
|
|
return ret;
|
|
}
|
|
nbd = idr_find(&nbd_index_idr, new_index);
|
|
}
|
|
} else {
|
|
nbd = idr_find(&nbd_index_idr, index);
|
|
if (!nbd) {
|
|
ret = nbd_dev_add(index);
|
|
if (ret < 0) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
printk(KERN_ERR "nbd: failed to add new device\n");
|
|
return ret;
|
|
}
|
|
nbd = idr_find(&nbd_index_idr, index);
|
|
}
|
|
}
|
|
if (!nbd) {
|
|
printk(KERN_ERR "nbd: couldn't find device at index %d\n",
|
|
index);
|
|
mutex_unlock(&nbd_index_mutex);
|
|
return -EINVAL;
|
|
}
|
|
if (!refcount_inc_not_zero(&nbd->refs)) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
if (index == -1)
|
|
goto again;
|
|
printk(KERN_ERR "nbd: device at index %d is going down\n",
|
|
index);
|
|
return -EINVAL;
|
|
}
|
|
mutex_unlock(&nbd_index_mutex);
|
|
|
|
mutex_lock(&nbd->config_lock);
|
|
if (refcount_read(&nbd->config_refs)) {
|
|
mutex_unlock(&nbd->config_lock);
|
|
nbd_put(nbd);
|
|
if (index == -1)
|
|
goto again;
|
|
printk(KERN_ERR "nbd: nbd%d already in use\n", index);
|
|
return -EBUSY;
|
|
}
|
|
if (WARN_ON(nbd->config)) {
|
|
mutex_unlock(&nbd->config_lock);
|
|
nbd_put(nbd);
|
|
return -EINVAL;
|
|
}
|
|
config = nbd->config = nbd_alloc_config();
|
|
if (!nbd->config) {
|
|
mutex_unlock(&nbd->config_lock);
|
|
nbd_put(nbd);
|
|
printk(KERN_ERR "nbd: couldn't allocate config\n");
|
|
return -ENOMEM;
|
|
}
|
|
refcount_set(&nbd->config_refs, 1);
|
|
set_bit(NBD_BOUND, &config->runtime_flags);
|
|
|
|
if (info->attrs[NBD_ATTR_SIZE_BYTES]) {
|
|
u64 bytes = nla_get_u64(info->attrs[NBD_ATTR_SIZE_BYTES]);
|
|
nbd_size_set(nbd, config->blksize,
|
|
div64_u64(bytes, config->blksize));
|
|
}
|
|
if (info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]) {
|
|
u64 bsize =
|
|
nla_get_u64(info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]);
|
|
nbd_size_set(nbd, bsize, div64_u64(config->bytesize, bsize));
|
|
}
|
|
if (info->attrs[NBD_ATTR_TIMEOUT]) {
|
|
u64 timeout = nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]);
|
|
nbd->tag_set.timeout = timeout * HZ;
|
|
blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
|
|
}
|
|
if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
|
|
config->dead_conn_timeout =
|
|
nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
|
|
config->dead_conn_timeout *= HZ;
|
|
}
|
|
if (info->attrs[NBD_ATTR_SERVER_FLAGS])
|
|
config->flags =
|
|
nla_get_u64(info->attrs[NBD_ATTR_SERVER_FLAGS]);
|
|
if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
|
|
u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
|
|
if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
|
|
set_bit(NBD_DESTROY_ON_DISCONNECT,
|
|
&config->runtime_flags);
|
|
put_dev = true;
|
|
}
|
|
}
|
|
|
|
if (info->attrs[NBD_ATTR_SOCKETS]) {
|
|
struct nlattr *attr;
|
|
int rem, fd;
|
|
|
|
nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS],
|
|
rem) {
|
|
struct nlattr *socks[NBD_SOCK_MAX+1];
|
|
|
|
if (nla_type(attr) != NBD_SOCK_ITEM) {
|
|
printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = nla_parse_nested(socks, NBD_SOCK_MAX, attr,
|
|
nbd_sock_policy, info->extack);
|
|
if (ret != 0) {
|
|
printk(KERN_ERR "nbd: error processing sock list\n");
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (!socks[NBD_SOCK_FD])
|
|
continue;
|
|
fd = (int)nla_get_u32(socks[NBD_SOCK_FD]);
|
|
ret = nbd_add_socket(nbd, fd, true);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
}
|
|
ret = nbd_start_device(nbd);
|
|
out:
|
|
mutex_unlock(&nbd->config_lock);
|
|
if (!ret) {
|
|
set_bit(NBD_HAS_CONFIG_REF, &config->runtime_flags);
|
|
refcount_inc(&nbd->config_refs);
|
|
nbd_connect_reply(info, nbd->index);
|
|
}
|
|
nbd_config_put(nbd);
|
|
if (put_dev)
|
|
nbd_put(nbd);
|
|
return ret;
|
|
}
|
|
|
|
static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
struct nbd_device *nbd;
|
|
int index;
|
|
|
|
if (!netlink_capable(skb, CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (!info->attrs[NBD_ATTR_INDEX]) {
|
|
printk(KERN_ERR "nbd: must specify an index to disconnect\n");
|
|
return -EINVAL;
|
|
}
|
|
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
|
|
mutex_lock(&nbd_index_mutex);
|
|
nbd = idr_find(&nbd_index_idr, index);
|
|
if (!nbd) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
printk(KERN_ERR "nbd: couldn't find device at index %d\n",
|
|
index);
|
|
return -EINVAL;
|
|
}
|
|
if (!refcount_inc_not_zero(&nbd->refs)) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
printk(KERN_ERR "nbd: device at index %d is going down\n",
|
|
index);
|
|
return -EINVAL;
|
|
}
|
|
mutex_unlock(&nbd_index_mutex);
|
|
if (!refcount_inc_not_zero(&nbd->config_refs)) {
|
|
nbd_put(nbd);
|
|
return 0;
|
|
}
|
|
mutex_lock(&nbd->config_lock);
|
|
nbd_disconnect(nbd);
|
|
mutex_unlock(&nbd->config_lock);
|
|
if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
|
|
&nbd->config->runtime_flags))
|
|
nbd_config_put(nbd);
|
|
nbd_config_put(nbd);
|
|
nbd_put(nbd);
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
struct nbd_device *nbd = NULL;
|
|
struct nbd_config *config;
|
|
int index;
|
|
int ret = -EINVAL;
|
|
bool put_dev = false;
|
|
|
|
if (!netlink_capable(skb, CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (!info->attrs[NBD_ATTR_INDEX]) {
|
|
printk(KERN_ERR "nbd: must specify a device to reconfigure\n");
|
|
return -EINVAL;
|
|
}
|
|
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
|
|
mutex_lock(&nbd_index_mutex);
|
|
nbd = idr_find(&nbd_index_idr, index);
|
|
if (!nbd) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
printk(KERN_ERR "nbd: couldn't find a device at index %d\n",
|
|
index);
|
|
return -EINVAL;
|
|
}
|
|
if (!refcount_inc_not_zero(&nbd->refs)) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
printk(KERN_ERR "nbd: device at index %d is going down\n",
|
|
index);
|
|
return -EINVAL;
|
|
}
|
|
mutex_unlock(&nbd_index_mutex);
|
|
|
|
if (!refcount_inc_not_zero(&nbd->config_refs)) {
|
|
dev_err(nbd_to_dev(nbd),
|
|
"not configured, cannot reconfigure\n");
|
|
nbd_put(nbd);
|
|
return -EINVAL;
|
|
}
|
|
|
|
mutex_lock(&nbd->config_lock);
|
|
config = nbd->config;
|
|
if (!test_bit(NBD_BOUND, &config->runtime_flags) ||
|
|
!nbd->task_recv) {
|
|
dev_err(nbd_to_dev(nbd),
|
|
"not configured, cannot reconfigure\n");
|
|
goto out;
|
|
}
|
|
|
|
if (info->attrs[NBD_ATTR_TIMEOUT]) {
|
|
u64 timeout = nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]);
|
|
nbd->tag_set.timeout = timeout * HZ;
|
|
blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
|
|
}
|
|
if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
|
|
config->dead_conn_timeout =
|
|
nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
|
|
config->dead_conn_timeout *= HZ;
|
|
}
|
|
if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
|
|
u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
|
|
if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
|
|
if (!test_and_set_bit(NBD_DESTROY_ON_DISCONNECT,
|
|
&config->runtime_flags))
|
|
put_dev = true;
|
|
} else {
|
|
if (test_and_clear_bit(NBD_DESTROY_ON_DISCONNECT,
|
|
&config->runtime_flags))
|
|
refcount_inc(&nbd->refs);
|
|
}
|
|
}
|
|
|
|
if (info->attrs[NBD_ATTR_SOCKETS]) {
|
|
struct nlattr *attr;
|
|
int rem, fd;
|
|
|
|
nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS],
|
|
rem) {
|
|
struct nlattr *socks[NBD_SOCK_MAX+1];
|
|
|
|
if (nla_type(attr) != NBD_SOCK_ITEM) {
|
|
printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = nla_parse_nested(socks, NBD_SOCK_MAX, attr,
|
|
nbd_sock_policy, info->extack);
|
|
if (ret != 0) {
|
|
printk(KERN_ERR "nbd: error processing sock list\n");
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (!socks[NBD_SOCK_FD])
|
|
continue;
|
|
fd = (int)nla_get_u32(socks[NBD_SOCK_FD]);
|
|
ret = nbd_reconnect_socket(nbd, fd);
|
|
if (ret) {
|
|
if (ret == -ENOSPC)
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
dev_info(nbd_to_dev(nbd), "reconnected socket\n");
|
|
}
|
|
}
|
|
out:
|
|
mutex_unlock(&nbd->config_lock);
|
|
nbd_config_put(nbd);
|
|
nbd_put(nbd);
|
|
if (put_dev)
|
|
nbd_put(nbd);
|
|
return ret;
|
|
}
|
|
|
|
static const struct genl_ops nbd_connect_genl_ops[] = {
|
|
{
|
|
.cmd = NBD_CMD_CONNECT,
|
|
.policy = nbd_attr_policy,
|
|
.doit = nbd_genl_connect,
|
|
},
|
|
{
|
|
.cmd = NBD_CMD_DISCONNECT,
|
|
.policy = nbd_attr_policy,
|
|
.doit = nbd_genl_disconnect,
|
|
},
|
|
{
|
|
.cmd = NBD_CMD_RECONFIGURE,
|
|
.policy = nbd_attr_policy,
|
|
.doit = nbd_genl_reconfigure,
|
|
},
|
|
{
|
|
.cmd = NBD_CMD_STATUS,
|
|
.policy = nbd_attr_policy,
|
|
.doit = nbd_genl_status,
|
|
},
|
|
};
|
|
|
|
static const struct genl_multicast_group nbd_mcast_grps[] = {
|
|
{ .name = NBD_GENL_MCAST_GROUP_NAME, },
|
|
};
|
|
|
|
static struct genl_family nbd_genl_family __ro_after_init = {
|
|
.hdrsize = 0,
|
|
.name = NBD_GENL_FAMILY_NAME,
|
|
.version = NBD_GENL_VERSION,
|
|
.module = THIS_MODULE,
|
|
.ops = nbd_connect_genl_ops,
|
|
.n_ops = ARRAY_SIZE(nbd_connect_genl_ops),
|
|
.maxattr = NBD_ATTR_MAX,
|
|
.mcgrps = nbd_mcast_grps,
|
|
.n_mcgrps = ARRAY_SIZE(nbd_mcast_grps),
|
|
};
|
|
|
|
static int populate_nbd_status(struct nbd_device *nbd, struct sk_buff *reply)
|
|
{
|
|
struct nlattr *dev_opt;
|
|
u8 connected = 0;
|
|
int ret;
|
|
|
|
/* This is a little racey, but for status it's ok. The
|
|
* reason we don't take a ref here is because we can't
|
|
* take a ref in the index == -1 case as we would need
|
|
* to put under the nbd_index_mutex, which could
|
|
* deadlock if we are configured to remove ourselves
|
|
* once we're disconnected.
|
|
*/
|
|
if (refcount_read(&nbd->config_refs))
|
|
connected = 1;
|
|
dev_opt = nla_nest_start(reply, NBD_DEVICE_ITEM);
|
|
if (!dev_opt)
|
|
return -EMSGSIZE;
|
|
ret = nla_put_u32(reply, NBD_DEVICE_INDEX, nbd->index);
|
|
if (ret)
|
|
return -EMSGSIZE;
|
|
ret = nla_put_u8(reply, NBD_DEVICE_CONNECTED,
|
|
connected);
|
|
if (ret)
|
|
return -EMSGSIZE;
|
|
nla_nest_end(reply, dev_opt);
|
|
return 0;
|
|
}
|
|
|
|
static int status_cb(int id, void *ptr, void *data)
|
|
{
|
|
struct nbd_device *nbd = ptr;
|
|
return populate_nbd_status(nbd, (struct sk_buff *)data);
|
|
}
|
|
|
|
static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
struct nlattr *dev_list;
|
|
struct sk_buff *reply;
|
|
void *reply_head;
|
|
size_t msg_size;
|
|
int index = -1;
|
|
int ret = -ENOMEM;
|
|
|
|
if (info->attrs[NBD_ATTR_INDEX])
|
|
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
|
|
|
|
mutex_lock(&nbd_index_mutex);
|
|
|
|
msg_size = nla_total_size(nla_attr_size(sizeof(u32)) +
|
|
nla_attr_size(sizeof(u8)));
|
|
msg_size *= (index == -1) ? nbd_total_devices : 1;
|
|
|
|
reply = genlmsg_new(msg_size, GFP_KERNEL);
|
|
if (!reply)
|
|
goto out;
|
|
reply_head = genlmsg_put_reply(reply, info, &nbd_genl_family, 0,
|
|
NBD_CMD_STATUS);
|
|
if (!reply_head) {
|
|
nlmsg_free(reply);
|
|
goto out;
|
|
}
|
|
|
|
dev_list = nla_nest_start(reply, NBD_ATTR_DEVICE_LIST);
|
|
if (index == -1) {
|
|
ret = idr_for_each(&nbd_index_idr, &status_cb, reply);
|
|
if (ret) {
|
|
nlmsg_free(reply);
|
|
goto out;
|
|
}
|
|
} else {
|
|
struct nbd_device *nbd;
|
|
nbd = idr_find(&nbd_index_idr, index);
|
|
if (nbd) {
|
|
ret = populate_nbd_status(nbd, reply);
|
|
if (ret) {
|
|
nlmsg_free(reply);
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
nla_nest_end(reply, dev_list);
|
|
genlmsg_end(reply, reply_head);
|
|
genlmsg_reply(reply, info);
|
|
ret = 0;
|
|
out:
|
|
mutex_unlock(&nbd_index_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static void nbd_connect_reply(struct genl_info *info, int index)
|
|
{
|
|
struct sk_buff *skb;
|
|
void *msg_head;
|
|
int ret;
|
|
|
|
skb = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
|
|
if (!skb)
|
|
return;
|
|
msg_head = genlmsg_put_reply(skb, info, &nbd_genl_family, 0,
|
|
NBD_CMD_CONNECT);
|
|
if (!msg_head) {
|
|
nlmsg_free(skb);
|
|
return;
|
|
}
|
|
ret = nla_put_u32(skb, NBD_ATTR_INDEX, index);
|
|
if (ret) {
|
|
nlmsg_free(skb);
|
|
return;
|
|
}
|
|
genlmsg_end(skb, msg_head);
|
|
genlmsg_reply(skb, info);
|
|
}
|
|
|
|
static void nbd_mcast_index(int index)
|
|
{
|
|
struct sk_buff *skb;
|
|
void *msg_head;
|
|
int ret;
|
|
|
|
skb = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
|
|
if (!skb)
|
|
return;
|
|
msg_head = genlmsg_put(skb, 0, 0, &nbd_genl_family, 0,
|
|
NBD_CMD_LINK_DEAD);
|
|
if (!msg_head) {
|
|
nlmsg_free(skb);
|
|
return;
|
|
}
|
|
ret = nla_put_u32(skb, NBD_ATTR_INDEX, index);
|
|
if (ret) {
|
|
nlmsg_free(skb);
|
|
return;
|
|
}
|
|
genlmsg_end(skb, msg_head);
|
|
genlmsg_multicast(&nbd_genl_family, skb, 0, 0, GFP_KERNEL);
|
|
}
|
|
|
|
static void nbd_dead_link_work(struct work_struct *work)
|
|
{
|
|
struct link_dead_args *args = container_of(work, struct link_dead_args,
|
|
work);
|
|
nbd_mcast_index(args->index);
|
|
kfree(args);
|
|
}
|
|
|
|
static int __init nbd_init(void)
|
|
{
|
|
int i;
|
|
|
|
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;
|
|
recv_workqueue = alloc_workqueue("knbd-recv",
|
|
WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
|
|
if (!recv_workqueue)
|
|
return -ENOMEM;
|
|
|
|
if (register_blkdev(NBD_MAJOR, "nbd")) {
|
|
destroy_workqueue(recv_workqueue);
|
|
return -EIO;
|
|
}
|
|
|
|
if (genl_register_family(&nbd_genl_family)) {
|
|
unregister_blkdev(NBD_MAJOR, "nbd");
|
|
destroy_workqueue(recv_workqueue);
|
|
return -EINVAL;
|
|
}
|
|
nbd_dbg_init();
|
|
|
|
mutex_lock(&nbd_index_mutex);
|
|
for (i = 0; i < nbds_max; i++)
|
|
nbd_dev_add(i);
|
|
mutex_unlock(&nbd_index_mutex);
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_exit_cb(int id, void *ptr, void *data)
|
|
{
|
|
struct list_head *list = (struct list_head *)data;
|
|
struct nbd_device *nbd = ptr;
|
|
|
|
list_add_tail(&nbd->list, list);
|
|
return 0;
|
|
}
|
|
|
|
static void __exit nbd_cleanup(void)
|
|
{
|
|
struct nbd_device *nbd;
|
|
LIST_HEAD(del_list);
|
|
|
|
nbd_dbg_close();
|
|
|
|
mutex_lock(&nbd_index_mutex);
|
|
idr_for_each(&nbd_index_idr, &nbd_exit_cb, &del_list);
|
|
mutex_unlock(&nbd_index_mutex);
|
|
|
|
while (!list_empty(&del_list)) {
|
|
nbd = list_first_entry(&del_list, struct nbd_device, list);
|
|
list_del_init(&nbd->list);
|
|
if (refcount_read(&nbd->refs) != 1)
|
|
printk(KERN_ERR "nbd: possibly leaking a device\n");
|
|
nbd_put(nbd);
|
|
}
|
|
|
|
idr_destroy(&nbd_index_idr);
|
|
genl_unregister_family(&nbd_genl_family);
|
|
destroy_workqueue(recv_workqueue);
|
|
unregister_blkdev(NBD_MAJOR, "nbd");
|
|
}
|
|
|
|
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: 16)");
|