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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Benjamin Coddington](/assets/img/avatar_default.png)
Since moving to memalloc_nofs_save/restore, SUNRPC has stopped setting the GFP_NOIO flag on sk_allocation which the networking system uses to decide when it is safe to use current->task_frag. The results of this are unexpected corruption in task_frag when SUNRPC is involved in memory reclaim. The corruption can be seen in crashes, but the root cause is often difficult to ascertain as a crashing machine's stack trace will have no evidence of being near NFS or SUNRPC code. I believe this problem to be much more pervasive than reports to the community may indicate. Fix this by having kernel users of sockets that may corrupt task_frag due to reclaim set sk_use_task_frag = false. Preemptively correcting this situation for users that still set sk_allocation allows them to convert to memalloc_nofs_save/restore without the same unexpected corruptions that are sure to follow, unlikely to show up in testing, and difficult to bisect. CC: Philipp Reisner <philipp.reisner@linbit.com> CC: Lars Ellenberg <lars.ellenberg@linbit.com> CC: "Christoph Böhmwalder" <christoph.boehmwalder@linbit.com> CC: Jens Axboe <axboe@kernel.dk> CC: Josef Bacik <josef@toxicpanda.com> CC: Keith Busch <kbusch@kernel.org> CC: Christoph Hellwig <hch@lst.de> CC: Sagi Grimberg <sagi@grimberg.me> CC: Lee Duncan <lduncan@suse.com> CC: Chris Leech <cleech@redhat.com> CC: Mike Christie <michael.christie@oracle.com> CC: "James E.J. Bottomley" <jejb@linux.ibm.com> CC: "Martin K. Petersen" <martin.petersen@oracle.com> CC: Valentina Manea <valentina.manea.m@gmail.com> CC: Shuah Khan <shuah@kernel.org> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: David Howells <dhowells@redhat.com> CC: Marc Dionne <marc.dionne@auristor.com> CC: Steve French <sfrench@samba.org> CC: Christine Caulfield <ccaulfie@redhat.com> CC: David Teigland <teigland@redhat.com> CC: Mark Fasheh <mark@fasheh.com> CC: Joel Becker <jlbec@evilplan.org> CC: Joseph Qi <joseph.qi@linux.alibaba.com> CC: Eric Van Hensbergen <ericvh@gmail.com> CC: Latchesar Ionkov <lucho@ionkov.net> CC: Dominique Martinet <asmadeus@codewreck.org> CC: Ilya Dryomov <idryomov@gmail.com> CC: Xiubo Li <xiubli@redhat.com> CC: Chuck Lever <chuck.lever@oracle.com> CC: Jeff Layton <jlayton@kernel.org> CC: Trond Myklebust <trond.myklebust@hammerspace.com> CC: Anna Schumaker <anna@kernel.org> CC: Steffen Klassert <steffen.klassert@secunet.com> CC: Herbert Xu <herbert@gondor.apana.org.au> Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2587 lines
64 KiB
C
2587 lines
64 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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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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* (part of code stolen from loop.c)
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*/
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#define pr_fmt(fmt) "nbd: " fmt
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#include <linux/major.h>
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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/completion.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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#define CREATE_TRACE_POINTS
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#include <trace/events/nbd.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 struct workqueue_struct *nbd_del_wq;
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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_RT_TIMEDOUT 0
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#define NBD_RT_DISCONNECT_REQUESTED 1
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#define NBD_RT_DISCONNECTED 2
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#define NBD_RT_HAS_PID_FILE 3
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#define NBD_RT_HAS_CONFIG_REF 4
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#define NBD_RT_BOUND 5
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#define NBD_RT_DISCONNECT_ON_CLOSE 6
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#define NBD_RT_HAS_BACKEND_FILE 7
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#define NBD_DESTROY_ON_DISCONNECT 0
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#define NBD_DISCONNECT_REQUESTED 1
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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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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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unsigned int blksize_bits;
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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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static inline unsigned int nbd_blksize(struct nbd_config *config)
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{
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return 1u << config->blksize_bits;
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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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struct workqueue_struct *recv_workq;
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struct work_struct remove_work;
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struct list_head list;
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struct task_struct *task_setup;
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unsigned long flags;
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pid_t pid; /* pid of nbd-client, if attached */
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char *backend;
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};
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#define NBD_CMD_REQUEUED 1
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/*
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* This flag will be set if nbd_queue_rq() succeed, and will be checked and
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* cleared in completion. Both setting and clearing of the flag are protected
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* by cmd->lock.
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*/
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#define NBD_CMD_INFLIGHT 2
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struct nbd_cmd {
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struct nbd_device *nbd;
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struct mutex lock;
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int index;
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int cookie;
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int retries;
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blk_status_t status;
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unsigned long flags;
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u32 cmd_cookie;
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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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#define nbd_name(nbd) ((nbd)->disk->disk_name)
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#define NBD_DEF_BLKSIZE_BITS 10
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static unsigned int nbds_max = 16;
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static int max_part = 16;
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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 void nbd_disconnect_and_put(struct nbd_device *nbd);
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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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static void nbd_requeue_cmd(struct nbd_cmd *cmd)
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{
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struct request *req = blk_mq_rq_from_pdu(cmd);
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if (!test_and_set_bit(NBD_CMD_REQUEUED, &cmd->flags))
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blk_mq_requeue_request(req, true);
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}
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#define NBD_COOKIE_BITS 32
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static u64 nbd_cmd_handle(struct nbd_cmd *cmd)
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{
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struct request *req = blk_mq_rq_from_pdu(cmd);
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u32 tag = blk_mq_unique_tag(req);
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u64 cookie = cmd->cmd_cookie;
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return (cookie << NBD_COOKIE_BITS) | tag;
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}
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static u32 nbd_handle_to_tag(u64 handle)
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{
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return (u32)handle;
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}
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static u32 nbd_handle_to_cookie(u64 handle)
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{
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return (u32)(handle >> NBD_COOKIE_BITS);
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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", nbd->pid);
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}
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static const struct device_attribute pid_attr = {
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.attr = { .name = "pid", .mode = 0444},
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.show = pid_show,
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};
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static ssize_t backend_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, "%s\n", nbd->backend ?: "");
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}
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static const struct device_attribute backend_attr = {
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.attr = { .name = "backend", .mode = 0444},
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.show = backend_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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del_gendisk(disk);
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put_disk(disk);
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blk_mq_free_tag_set(&nbd->tag_set);
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/*
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* Remove from idr after del_gendisk() completes, so if the same ID is
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* reused, the following add_disk() will succeed.
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*/
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mutex_lock(&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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destroy_workqueue(nbd->recv_workq);
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kfree(nbd);
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}
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static void nbd_dev_remove_work(struct work_struct *work)
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{
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nbd_dev_remove(container_of(work, struct nbd_device, remove_work));
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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_test(&nbd->refs))
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return;
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/* Call del_gendisk() asynchrounously to prevent deadlock */
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if (test_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags))
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queue_work(nbd_del_wq, &nbd->remove_work);
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else
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nbd_dev_remove(nbd);
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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_RT_DISCONNECTED, &config->runtime_flags) ||
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test_bit(NBD_RT_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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if (atomic_dec_return(&nbd->config->live_connections) == 0) {
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if (test_and_clear_bit(NBD_RT_DISCONNECT_REQUESTED,
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&nbd->config->runtime_flags)) {
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set_bit(NBD_RT_DISCONNECTED,
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&nbd->config->runtime_flags);
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dev_info(nbd_to_dev(nbd),
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"Disconnected due to user request.\n");
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}
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}
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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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static int nbd_set_size(struct nbd_device *nbd, loff_t bytesize,
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loff_t blksize)
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{
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if (!blksize)
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blksize = 1u << NBD_DEF_BLKSIZE_BITS;
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if (blk_validate_block_size(blksize))
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return -EINVAL;
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nbd->config->bytesize = bytesize;
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nbd->config->blksize_bits = __ffs(blksize);
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if (!nbd->pid)
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return 0;
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if (nbd->config->flags & NBD_FLAG_SEND_TRIM) {
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nbd->disk->queue->limits.discard_granularity = blksize;
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blk_queue_max_discard_sectors(nbd->disk->queue, UINT_MAX);
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}
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blk_queue_logical_block_size(nbd->disk->queue, blksize);
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blk_queue_physical_block_size(nbd->disk->queue, blksize);
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if (max_part)
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set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
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if (!set_capacity_and_notify(nbd->disk, bytesize >> 9))
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kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
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return 0;
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}
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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);
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dev_dbg(nbd_to_dev(cmd->nbd), "request %p: %s\n", req,
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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_RT_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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}
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static u32 req_to_nbd_cmd_type(struct request *req)
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{
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switch (req_op(req)) {
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case REQ_OP_DISCARD:
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return NBD_CMD_TRIM;
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case REQ_OP_FLUSH:
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return NBD_CMD_FLUSH;
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case REQ_OP_WRITE:
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return NBD_CMD_WRITE;
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case REQ_OP_READ:
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return NBD_CMD_READ;
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default:
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return U32_MAX;
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}
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}
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static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req)
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{
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struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
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struct nbd_device *nbd = cmd->nbd;
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struct nbd_config *config;
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if (!mutex_trylock(&cmd->lock))
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return BLK_EH_RESET_TIMER;
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if (!test_bit(NBD_CMD_INFLIGHT, &cmd->flags)) {
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mutex_unlock(&cmd->lock);
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return BLK_EH_DONE;
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}
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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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__clear_bit(NBD_CMD_INFLIGHT, &cmd->flags);
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mutex_unlock(&cmd->lock);
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goto done;
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}
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config = nbd->config;
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if (config->num_connections > 1 ||
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(config->num_connections == 1 && nbd->tag_set.timeout)) {
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dev_err_ratelimited(nbd_to_dev(nbd),
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"Connection timed out, retrying (%d/%d alive)\n",
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atomic_read(&config->live_connections),
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config->num_connections);
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/*
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* Hooray we have more connections, requeue this IO, the submit
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* path will put it on a real connection. Or if only one
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* connection is configured, the submit path will wait util
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* a new connection is reconfigured or util dead timeout.
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*/
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if (config->socks) {
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if (cmd->index < config->num_connections) {
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struct nbd_sock *nsock =
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config->socks[cmd->index];
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mutex_lock(&nsock->tx_lock);
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/* We can have multiple outstanding requests, so
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* we don't want to mark the nsock dead if we've
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* already reconnected with a new socket, so
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* only mark it dead if its the same socket we
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* were sent out on.
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*/
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if (cmd->cookie == nsock->cookie)
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nbd_mark_nsock_dead(nbd, nsock, 1);
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mutex_unlock(&nsock->tx_lock);
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}
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mutex_unlock(&cmd->lock);
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nbd_requeue_cmd(cmd);
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nbd_config_put(nbd);
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return BLK_EH_DONE;
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}
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|
}
|
|
|
|
if (!nbd->tag_set.timeout) {
|
|
/*
|
|
* Userspace sets timeout=0 to disable socket disconnection,
|
|
* so just warn and reset the timer.
|
|
*/
|
|
struct nbd_sock *nsock = config->socks[cmd->index];
|
|
cmd->retries++;
|
|
dev_info(nbd_to_dev(nbd), "Possible stuck request %p: control (%s@%llu,%uB). Runtime %u seconds\n",
|
|
req, nbdcmd_to_ascii(req_to_nbd_cmd_type(req)),
|
|
(unsigned long long)blk_rq_pos(req) << 9,
|
|
blk_rq_bytes(req), (req->timeout / HZ) * cmd->retries);
|
|
|
|
mutex_lock(&nsock->tx_lock);
|
|
if (cmd->cookie != nsock->cookie) {
|
|
nbd_requeue_cmd(cmd);
|
|
mutex_unlock(&nsock->tx_lock);
|
|
mutex_unlock(&cmd->lock);
|
|
nbd_config_put(nbd);
|
|
return BLK_EH_DONE;
|
|
}
|
|
mutex_unlock(&nsock->tx_lock);
|
|
mutex_unlock(&cmd->lock);
|
|
nbd_config_put(nbd);
|
|
return BLK_EH_RESET_TIMER;
|
|
}
|
|
|
|
dev_err_ratelimited(nbd_to_dev(nbd), "Connection timed out\n");
|
|
set_bit(NBD_RT_TIMEDOUT, &config->runtime_flags);
|
|
cmd->status = BLK_STS_IOERR;
|
|
__clear_bit(NBD_CMD_INFLIGHT, &cmd->flags);
|
|
mutex_unlock(&cmd->lock);
|
|
sock_shutdown(nbd);
|
|
nbd_config_put(nbd);
|
|
done:
|
|
blk_mq_complete_request(req);
|
|
return BLK_EH_DONE;
|
|
}
|
|
|
|
/*
|
|
* Send or receive packet. Return a positive value on success and
|
|
* negtive value on failue, and never return 0.
|
|
*/
|
|
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;
|
|
sock->sk->sk_use_task_frag = false;
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Different settings for sk->sk_sndtimeo can result in different return values
|
|
* if there is a signal pending when we enter sendmsg, because reasons?
|
|
*/
|
|
static inline int was_interrupted(int result)
|
|
{
|
|
return result == -ERESTARTSYS || result == -EINTR;
|
|
}
|
|
|
|
/* 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;
|
|
u64 handle;
|
|
u32 type;
|
|
u32 nbd_cmd_flags = 0;
|
|
int sent = nsock->sent, skip = 0;
|
|
|
|
iov_iter_kvec(&from, ITER_SOURCE, &iov, 1, sizeof(request));
|
|
|
|
type = req_to_nbd_cmd_type(req);
|
|
if (type == U32_MAX)
|
|
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);
|
|
|
|
/* initialize handle for tracing purposes */
|
|
handle = nbd_cmd_handle(cmd);
|
|
|
|
goto send_pages;
|
|
}
|
|
iov_iter_advance(&from, sent);
|
|
} else {
|
|
cmd->cmd_cookie++;
|
|
}
|
|
cmd->index = index;
|
|
cmd->cookie = nsock->cookie;
|
|
cmd->retries = 0;
|
|
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);
|
|
}
|
|
handle = nbd_cmd_handle(cmd);
|
|
memcpy(request.handle, &handle, sizeof(handle));
|
|
|
|
trace_nbd_send_request(&request, nbd->index, blk_mq_rq_from_pdu(cmd));
|
|
|
|
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, index, 1, &from,
|
|
(type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent);
|
|
trace_nbd_header_sent(req, handle);
|
|
if (result < 0) {
|
|
if (was_interrupted(result)) {
|
|
/* 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;
|
|
}
|
|
set_bit(NBD_CMD_REQUEUED, &cmd->flags);
|
|
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",
|
|
req, bvec.bv_len);
|
|
iov_iter_bvec(&from, ITER_SOURCE, &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 (was_interrupted(result)) {
|
|
/* We've already sent the header, we
|
|
* have no choice but to set pending and
|
|
* return BUSY.
|
|
*/
|
|
nsock->pending = req;
|
|
nsock->sent = sent;
|
|
set_bit(NBD_CMD_REQUEUED, &cmd->flags);
|
|
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:
|
|
trace_nbd_payload_sent(req, handle);
|
|
nsock->pending = NULL;
|
|
nsock->sent = 0;
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_read_reply(struct nbd_device *nbd, int index,
|
|
struct nbd_reply *reply)
|
|
{
|
|
struct kvec iov = {.iov_base = reply, .iov_len = sizeof(*reply)};
|
|
struct iov_iter to;
|
|
int result;
|
|
|
|
reply->magic = 0;
|
|
iov_iter_kvec(&to, ITER_DEST, &iov, 1, sizeof(*reply));
|
|
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
|
|
if (result < 0) {
|
|
if (!nbd_disconnected(nbd->config))
|
|
dev_err(disk_to_dev(nbd->disk),
|
|
"Receive control failed (result %d)\n", result);
|
|
return 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 -EPROTO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* NULL returned = something went wrong, inform userspace */
|
|
static struct nbd_cmd *nbd_handle_reply(struct nbd_device *nbd, int index,
|
|
struct nbd_reply *reply)
|
|
{
|
|
int result;
|
|
struct nbd_cmd *cmd;
|
|
struct request *req = NULL;
|
|
u64 handle;
|
|
u16 hwq;
|
|
u32 tag;
|
|
int ret = 0;
|
|
|
|
memcpy(&handle, reply->handle, sizeof(handle));
|
|
tag = nbd_handle_to_tag(handle);
|
|
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);
|
|
}
|
|
trace_nbd_header_received(req, handle);
|
|
cmd = blk_mq_rq_to_pdu(req);
|
|
|
|
mutex_lock(&cmd->lock);
|
|
if (!test_bit(NBD_CMD_INFLIGHT, &cmd->flags)) {
|
|
dev_err(disk_to_dev(nbd->disk), "Suspicious reply %d (status %u flags %lu)",
|
|
tag, cmd->status, cmd->flags);
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
if (cmd->index != index) {
|
|
dev_err(disk_to_dev(nbd->disk), "Unexpected reply %d from different sock %d (expected %d)",
|
|
tag, index, cmd->index);
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
if (cmd->cmd_cookie != nbd_handle_to_cookie(handle)) {
|
|
dev_err(disk_to_dev(nbd->disk), "Double reply on req %p, cmd_cookie %u, handle cookie %u\n",
|
|
req, cmd->cmd_cookie, nbd_handle_to_cookie(handle));
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
if (cmd->status != BLK_STS_OK) {
|
|
dev_err(disk_to_dev(nbd->disk), "Command already handled %p\n",
|
|
req);
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
if (test_bit(NBD_CMD_REQUEUED, &cmd->flags)) {
|
|
dev_err(disk_to_dev(nbd->disk), "Raced with timeout on req %p\n",
|
|
req);
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
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;
|
|
goto out;
|
|
}
|
|
|
|
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;
|
|
struct iov_iter to;
|
|
|
|
rq_for_each_segment(bvec, req, iter) {
|
|
iov_iter_bvec(&to, ITER_DEST, &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, 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(nbd->config)) {
|
|
cmd->status = BLK_STS_IOERR;
|
|
goto out;
|
|
}
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
|
|
req, bvec.bv_len);
|
|
}
|
|
}
|
|
out:
|
|
trace_nbd_payload_received(req, handle);
|
|
mutex_unlock(&cmd->lock);
|
|
return ret ? ERR_PTR(ret) : 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 request_queue *q = nbd->disk->queue;
|
|
struct nbd_sock *nsock;
|
|
struct nbd_cmd *cmd;
|
|
struct request *rq;
|
|
|
|
while (1) {
|
|
struct nbd_reply reply;
|
|
|
|
if (nbd_read_reply(nbd, args->index, &reply))
|
|
break;
|
|
|
|
/*
|
|
* Grab .q_usage_counter so request pool won't go away, then no
|
|
* request use-after-free is possible during nbd_handle_reply().
|
|
* If queue is frozen, there won't be any inflight requests, we
|
|
* needn't to handle the incoming garbage message.
|
|
*/
|
|
if (!percpu_ref_tryget(&q->q_usage_counter)) {
|
|
dev_err(disk_to_dev(nbd->disk), "%s: no io inflight\n",
|
|
__func__);
|
|
break;
|
|
}
|
|
|
|
cmd = nbd_handle_reply(nbd, args->index, &reply);
|
|
if (IS_ERR(cmd)) {
|
|
percpu_ref_put(&q->q_usage_counter);
|
|
break;
|
|
}
|
|
|
|
rq = blk_mq_rq_from_pdu(cmd);
|
|
if (likely(!blk_should_fake_timeout(rq->q))) {
|
|
bool complete;
|
|
|
|
mutex_lock(&cmd->lock);
|
|
complete = __test_and_clear_bit(NBD_CMD_INFLIGHT,
|
|
&cmd->flags);
|
|
mutex_unlock(&cmd->lock);
|
|
if (complete)
|
|
blk_mq_complete_request(rq);
|
|
}
|
|
percpu_ref_put(&q->q_usage_counter);
|
|
}
|
|
|
|
nsock = config->socks[args->index];
|
|
mutex_lock(&nsock->tx_lock);
|
|
nbd_mark_nsock_dead(nbd, nsock, 1);
|
|
mutex_unlock(&nsock->tx_lock);
|
|
|
|
nbd_config_put(nbd);
|
|
atomic_dec(&config->recv_threads);
|
|
wake_up(&config->recv_wq);
|
|
kfree(args);
|
|
}
|
|
|
|
static bool nbd_clear_req(struct request *req, void *data)
|
|
{
|
|
struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
|
|
|
|
/* don't abort one completed request */
|
|
if (blk_mq_request_completed(req))
|
|
return true;
|
|
|
|
mutex_lock(&cmd->lock);
|
|
if (!__test_and_clear_bit(NBD_CMD_INFLIGHT, &cmd->flags)) {
|
|
mutex_unlock(&cmd->lock);
|
|
return true;
|
|
}
|
|
cmd->status = BLK_STS_IOERR;
|
|
mutex_unlock(&cmd->lock);
|
|
|
|
blk_mq_complete_request(req);
|
|
return true;
|
|
}
|
|
|
|
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_RT_DISCONNECTED, &config->runtime_flags))
|
|
return new_index;
|
|
|
|
if (config->num_connections <= 1) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Dead connection, failed to find a fallback\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 (!wait_event_timeout(config->conn_wait,
|
|
test_bit(NBD_RT_DISCONNECTED,
|
|
&config->runtime_flags) ||
|
|
atomic_read(&config->live_connections) > 0,
|
|
config->dead_conn_timeout))
|
|
return 0;
|
|
|
|
return !test_bit(NBD_RT_DISCONNECTED, &config->runtime_flags);
|
|
}
|
|
|
|
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.
|
|
*/
|
|
blk_mq_start_request(req);
|
|
if (unlikely(nsock->pending && nsock->pending != req)) {
|
|
nbd_requeue_cmd(cmd);
|
|
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);
|
|
/*
|
|
* Access to this flag is protected by cmd->lock, thus it's safe to set
|
|
* the flag after nbd_send_cmd() succeed to send request to server.
|
|
*/
|
|
if (!ret)
|
|
__set_bit(NBD_CMD_INFLIGHT, &cmd->flags);
|
|
else if (ret == -EAGAIN) {
|
|
dev_err_ratelimited(disk_to_dev(nbd->disk),
|
|
"Request send failed, requeueing\n");
|
|
nbd_mark_nsock_dead(nbd, nsock, 1);
|
|
nbd_requeue_cmd(cmd);
|
|
ret = 0;
|
|
}
|
|
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.
|
|
*/
|
|
mutex_lock(&cmd->lock);
|
|
clear_bit(NBD_CMD_REQUEUED, &cmd->flags);
|
|
|
|
/* 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;
|
|
mutex_unlock(&cmd->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct socket *nbd_get_socket(struct nbd_device *nbd, unsigned long fd,
|
|
int *err)
|
|
{
|
|
struct socket *sock;
|
|
|
|
*err = 0;
|
|
sock = sockfd_lookup(fd, err);
|
|
if (!sock)
|
|
return NULL;
|
|
|
|
if (sock->ops->shutdown == sock_no_shutdown) {
|
|
dev_err(disk_to_dev(nbd->disk), "Unsupported socket: shutdown callout must be supported.\n");
|
|
*err = -EINVAL;
|
|
sockfd_put(sock);
|
|
return NULL;
|
|
}
|
|
|
|
return sock;
|
|
}
|
|
|
|
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 = nbd_get_socket(nbd, arg, &err);
|
|
if (!sock)
|
|
return err;
|
|
|
|
/*
|
|
* We need to make sure we don't get any errant requests while we're
|
|
* reallocating the ->socks array.
|
|
*/
|
|
blk_mq_freeze_queue(nbd->disk->queue);
|
|
|
|
if (!netlink && !nbd->task_setup &&
|
|
!test_bit(NBD_RT_BOUND, &config->runtime_flags))
|
|
nbd->task_setup = current;
|
|
|
|
if (!netlink &&
|
|
(nbd->task_setup != current ||
|
|
test_bit(NBD_RT_BOUND, &config->runtime_flags))) {
|
|
dev_err(disk_to_dev(nbd->disk),
|
|
"Device being setup by another task");
|
|
err = -EBUSY;
|
|
goto put_socket;
|
|
}
|
|
|
|
nsock = kzalloc(sizeof(*nsock), GFP_KERNEL);
|
|
if (!nsock) {
|
|
err = -ENOMEM;
|
|
goto put_socket;
|
|
}
|
|
|
|
socks = krealloc(config->socks, (config->num_connections + 1) *
|
|
sizeof(struct nbd_sock *), GFP_KERNEL);
|
|
if (!socks) {
|
|
kfree(nsock);
|
|
err = -ENOMEM;
|
|
goto put_socket;
|
|
}
|
|
|
|
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);
|
|
blk_mq_unfreeze_queue(nbd->disk->queue);
|
|
|
|
return 0;
|
|
|
|
put_socket:
|
|
blk_mq_unfreeze_queue(nbd->disk->queue);
|
|
sockfd_put(sock);
|
|
return err;
|
|
}
|
|
|
|
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 = nbd_get_socket(nbd, 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_RT_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(nbd->recv_workq, &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 nbd_device *nbd)
|
|
{
|
|
if (disk_openers(nbd->disk) > 1)
|
|
return;
|
|
set_capacity(nbd->disk, 0);
|
|
}
|
|
|
|
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_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, ITER_SOURCE, &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_RT_DISCONNECT_REQUESTED, &config->runtime_flags);
|
|
set_bit(NBD_DISCONNECT_REQUESTED, &nbd->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);
|
|
invalidate_disk(nbd->disk);
|
|
if (nbd->config->bytesize)
|
|
kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
|
|
if (test_and_clear_bit(NBD_RT_HAS_PID_FILE,
|
|
&config->runtime_flags))
|
|
device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
|
|
nbd->pid = 0;
|
|
if (test_and_clear_bit(NBD_RT_HAS_BACKEND_FILE,
|
|
&config->runtime_flags)) {
|
|
device_remove_file(disk_to_dev(nbd->disk), &backend_attr);
|
|
kfree(nbd->backend);
|
|
nbd->backend = 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;
|
|
nbd->disk->queue->limits.discard_granularity = 0;
|
|
blk_queue_max_discard_sectors(nbd->disk->queue, 0);
|
|
|
|
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->pid)
|
|
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->pid = task_pid_nr(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 for pid!\n");
|
|
return error;
|
|
}
|
|
set_bit(NBD_RT_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);
|
|
/*
|
|
* If num_connections is m (2 < m),
|
|
* and NO.1 ~ NO.n(1 < n < m) kzallocs are successful.
|
|
* But NO.(n + 1) failed. We still have n recv threads.
|
|
* So, add flush_workqueue here to prevent recv threads
|
|
* dropping the last config_refs and trying to destroy
|
|
* the workqueue from inside the workqueue.
|
|
*/
|
|
if (i)
|
|
flush_workqueue(nbd->recv_workq);
|
|
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(nbd->recv_workq, &args->work);
|
|
}
|
|
return nbd_set_size(nbd, config->bytesize, nbd_blksize(config));
|
|
}
|
|
|
|
static int nbd_start_device_ioctl(struct nbd_device *nbd)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
int ret;
|
|
|
|
ret = nbd_start_device(nbd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (max_part)
|
|
set_bit(GD_NEED_PART_SCAN, &nbd->disk->state);
|
|
mutex_unlock(&nbd->config_lock);
|
|
ret = wait_event_interruptible(config->recv_wq,
|
|
atomic_read(&config->recv_threads) == 0);
|
|
if (ret) {
|
|
sock_shutdown(nbd);
|
|
nbd_clear_que(nbd);
|
|
}
|
|
|
|
flush_workqueue(nbd->recv_workq);
|
|
mutex_lock(&nbd->config_lock);
|
|
nbd_bdev_reset(nbd);
|
|
/* user requested, ignore socket errors */
|
|
if (test_bit(NBD_RT_DISCONNECT_REQUESTED, &config->runtime_flags))
|
|
ret = 0;
|
|
if (test_bit(NBD_RT_TIMEDOUT, &config->runtime_flags))
|
|
ret = -ETIMEDOUT;
|
|
return ret;
|
|
}
|
|
|
|
static void nbd_clear_sock_ioctl(struct nbd_device *nbd,
|
|
struct block_device *bdev)
|
|
{
|
|
nbd_clear_sock(nbd);
|
|
__invalidate_device(bdev, true);
|
|
nbd_bdev_reset(nbd);
|
|
if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF,
|
|
&nbd->config->runtime_flags))
|
|
nbd_config_put(nbd);
|
|
}
|
|
|
|
static void nbd_set_cmd_timeout(struct nbd_device *nbd, u64 timeout)
|
|
{
|
|
nbd->tag_set.timeout = timeout * HZ;
|
|
if (timeout)
|
|
blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
|
|
else
|
|
blk_queue_rq_timeout(nbd->disk->queue, 30 * HZ);
|
|
}
|
|
|
|
/* 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;
|
|
loff_t bytesize;
|
|
|
|
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:
|
|
return nbd_set_size(nbd, config->bytesize, arg);
|
|
case NBD_SET_SIZE:
|
|
return nbd_set_size(nbd, arg, nbd_blksize(config));
|
|
case NBD_SET_SIZE_BLOCKS:
|
|
if (check_shl_overflow(arg, config->blksize_bits, &bytesize))
|
|
return -EINVAL;
|
|
return nbd_set_size(nbd, bytesize, nbd_blksize(config));
|
|
case NBD_SET_TIMEOUT:
|
|
nbd_set_cmd_timeout(nbd, arg);
|
|
return 0;
|
|
|
|
case NBD_SET_FLAGS:
|
|
config->flags = arg;
|
|
return 0;
|
|
case NBD_DO_IT:
|
|
return nbd_start_device_ioctl(nbd);
|
|
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_RT_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;
|
|
|
|
if (!try_module_get(THIS_MODULE))
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
config = kzalloc(sizeof(struct nbd_config), GFP_NOFS);
|
|
if (!config) {
|
|
module_put(THIS_MODULE);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
atomic_set(&config->recv_threads, 0);
|
|
init_waitqueue_head(&config->recv_wq);
|
|
init_waitqueue_head(&config->conn_wait);
|
|
config->blksize_bits = NBD_DEF_BLKSIZE_BITS;
|
|
atomic_set(&config->live_connections, 0);
|
|
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_alloc_config();
|
|
if (IS_ERR(config)) {
|
|
ret = PTR_ERR(config);
|
|
mutex_unlock(&nbd->config_lock);
|
|
goto out;
|
|
}
|
|
nbd->config = config;
|
|
refcount_set(&nbd->config_refs, 1);
|
|
refcount_inc(&nbd->refs);
|
|
mutex_unlock(&nbd->config_lock);
|
|
if (max_part)
|
|
set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
|
|
} else if (nbd_disconnected(nbd->config)) {
|
|
if (max_part)
|
|
set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
|
|
}
|
|
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;
|
|
|
|
if (test_bit(NBD_RT_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) &&
|
|
disk_openers(disk) == 0)
|
|
nbd_disconnect_and_put(nbd);
|
|
|
|
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->pid)
|
|
seq_printf(s, "recv: %d\n", nbd->pid);
|
|
|
|
return 0;
|
|
}
|
|
|
|
DEFINE_SHOW_ATTRIBUTE(nbd_dbg_tasks);
|
|
|
|
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;
|
|
}
|
|
|
|
DEFINE_SHOW_ATTRIBUTE(nbd_dbg_flags);
|
|
|
|
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_fops);
|
|
debugfs_create_u64("size_bytes", 0444, dir, &config->bytesize);
|
|
debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout);
|
|
debugfs_create_u32("blocksize_bits", 0444, dir, &config->blksize_bits);
|
|
debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_fops);
|
|
|
|
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;
|
|
cmd->flags = 0;
|
|
mutex_init(&cmd->lock);
|
|
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 struct nbd_device *nbd_dev_add(int index, unsigned int refs)
|
|
{
|
|
struct nbd_device *nbd;
|
|
struct gendisk *disk;
|
|
int err = -ENOMEM;
|
|
|
|
nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL);
|
|
if (!nbd)
|
|
goto out;
|
|
|
|
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_BLOCKING;
|
|
nbd->tag_set.driver_data = nbd;
|
|
INIT_WORK(&nbd->remove_work, nbd_dev_remove_work);
|
|
nbd->backend = NULL;
|
|
|
|
err = blk_mq_alloc_tag_set(&nbd->tag_set);
|
|
if (err)
|
|
goto out_free_nbd;
|
|
|
|
mutex_lock(&nbd_index_mutex);
|
|
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;
|
|
}
|
|
nbd->index = index;
|
|
mutex_unlock(&nbd_index_mutex);
|
|
if (err < 0)
|
|
goto out_free_tags;
|
|
|
|
disk = blk_mq_alloc_disk(&nbd->tag_set, NULL);
|
|
if (IS_ERR(disk)) {
|
|
err = PTR_ERR(disk);
|
|
goto out_free_idr;
|
|
}
|
|
nbd->disk = disk;
|
|
|
|
nbd->recv_workq = alloc_workqueue("nbd%d-recv",
|
|
WQ_MEM_RECLAIM | WQ_HIGHPRI |
|
|
WQ_UNBOUND, 0, nbd->index);
|
|
if (!nbd->recv_workq) {
|
|
dev_err(disk_to_dev(nbd->disk), "Could not allocate knbd recv work queue.\n");
|
|
err = -ENOMEM;
|
|
goto out_err_disk;
|
|
}
|
|
|
|
/*
|
|
* Tell the block layer that we are not a rotational device
|
|
*/
|
|
blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
|
|
blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue);
|
|
disk->queue->limits.discard_granularity = 0;
|
|
blk_queue_max_discard_sectors(disk->queue, 0);
|
|
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);
|
|
/*
|
|
* Start out with a zero references to keep other threads from using
|
|
* this device until it is fully initialized.
|
|
*/
|
|
refcount_set(&nbd->refs, 0);
|
|
INIT_LIST_HEAD(&nbd->list);
|
|
disk->major = NBD_MAJOR;
|
|
disk->first_minor = index << part_shift;
|
|
disk->minors = 1 << part_shift;
|
|
disk->fops = &nbd_fops;
|
|
disk->private_data = nbd;
|
|
sprintf(disk->disk_name, "nbd%d", index);
|
|
err = add_disk(disk);
|
|
if (err)
|
|
goto out_free_work;
|
|
|
|
/*
|
|
* Now publish the device.
|
|
*/
|
|
refcount_set(&nbd->refs, refs);
|
|
nbd_total_devices++;
|
|
return nbd;
|
|
|
|
out_free_work:
|
|
destroy_workqueue(nbd->recv_workq);
|
|
out_err_disk:
|
|
put_disk(disk);
|
|
out_free_idr:
|
|
mutex_lock(&nbd_index_mutex);
|
|
idr_remove(&nbd_index_idr, index);
|
|
mutex_unlock(&nbd_index_mutex);
|
|
out_free_tags:
|
|
blk_mq_free_tag_set(&nbd->tag_set);
|
|
out_free_nbd:
|
|
kfree(nbd);
|
|
out:
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static struct nbd_device *nbd_find_get_unused(void)
|
|
{
|
|
struct nbd_device *nbd;
|
|
int id;
|
|
|
|
lockdep_assert_held(&nbd_index_mutex);
|
|
|
|
idr_for_each_entry(&nbd_index_idr, nbd, id) {
|
|
if (refcount_read(&nbd->config_refs) ||
|
|
test_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags))
|
|
continue;
|
|
if (refcount_inc_not_zero(&nbd->refs))
|
|
return nbd;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Netlink interface. */
|
|
static const 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},
|
|
[NBD_ATTR_BACKEND_IDENTIFIER] = { .type = NLA_STRING},
|
|
};
|
|
|
|
static const 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 const 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_size_set(struct genl_info *info, struct nbd_device *nbd)
|
|
{
|
|
struct nbd_config *config = nbd->config;
|
|
u64 bsize = nbd_blksize(config);
|
|
u64 bytes = config->bytesize;
|
|
|
|
if (info->attrs[NBD_ATTR_SIZE_BYTES])
|
|
bytes = nla_get_u64(info->attrs[NBD_ATTR_SIZE_BYTES]);
|
|
|
|
if (info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES])
|
|
bsize = nla_get_u64(info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]);
|
|
|
|
if (bytes != config->bytesize || bsize != nbd_blksize(config))
|
|
return nbd_set_size(nbd, bytes, bsize);
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
struct nbd_device *nbd;
|
|
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]);
|
|
|
|
/*
|
|
* Too big first_minor can cause duplicate creation of
|
|
* sysfs files/links, since index << part_shift might overflow, or
|
|
* MKDEV() expect that the max bits of first_minor is 20.
|
|
*/
|
|
if (index < 0 || index > MINORMASK >> part_shift) {
|
|
pr_err("illegal input index %d\n", index);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (!info->attrs[NBD_ATTR_SOCKETS]) {
|
|
pr_err("must specify at least one socket\n");
|
|
return -EINVAL;
|
|
}
|
|
if (!info->attrs[NBD_ATTR_SIZE_BYTES]) {
|
|
pr_err("must specify a size in bytes for the device\n");
|
|
return -EINVAL;
|
|
}
|
|
again:
|
|
mutex_lock(&nbd_index_mutex);
|
|
if (index == -1) {
|
|
nbd = nbd_find_get_unused();
|
|
} else {
|
|
nbd = idr_find(&nbd_index_idr, index);
|
|
if (nbd) {
|
|
if ((test_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags) &&
|
|
test_bit(NBD_DISCONNECT_REQUESTED, &nbd->flags)) ||
|
|
!refcount_inc_not_zero(&nbd->refs)) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
pr_err("device at index %d is going down\n",
|
|
index);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
}
|
|
mutex_unlock(&nbd_index_mutex);
|
|
|
|
if (!nbd) {
|
|
nbd = nbd_dev_add(index, 2);
|
|
if (IS_ERR(nbd)) {
|
|
pr_err("failed to add new device\n");
|
|
return PTR_ERR(nbd);
|
|
}
|
|
}
|
|
|
|
mutex_lock(&nbd->config_lock);
|
|
if (refcount_read(&nbd->config_refs)) {
|
|
mutex_unlock(&nbd->config_lock);
|
|
nbd_put(nbd);
|
|
if (index == -1)
|
|
goto again;
|
|
pr_err("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_alloc_config();
|
|
if (IS_ERR(config)) {
|
|
mutex_unlock(&nbd->config_lock);
|
|
nbd_put(nbd);
|
|
pr_err("couldn't allocate config\n");
|
|
return PTR_ERR(config);
|
|
}
|
|
nbd->config = config;
|
|
refcount_set(&nbd->config_refs, 1);
|
|
set_bit(NBD_RT_BOUND, &config->runtime_flags);
|
|
|
|
ret = nbd_genl_size_set(info, nbd);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (info->attrs[NBD_ATTR_TIMEOUT])
|
|
nbd_set_cmd_timeout(nbd,
|
|
nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]));
|
|
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) {
|
|
/*
|
|
* We have 1 ref to keep the device around, and then 1
|
|
* ref for our current operation here, which will be
|
|
* inherited by the config. If we already have
|
|
* DESTROY_ON_DISCONNECT set then we know we don't have
|
|
* that extra ref already held so we don't need the
|
|
* put_dev.
|
|
*/
|
|
if (!test_and_set_bit(NBD_DESTROY_ON_DISCONNECT,
|
|
&nbd->flags))
|
|
put_dev = true;
|
|
} else {
|
|
if (test_and_clear_bit(NBD_DESTROY_ON_DISCONNECT,
|
|
&nbd->flags))
|
|
refcount_inc(&nbd->refs);
|
|
}
|
|
if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
|
|
set_bit(NBD_RT_DISCONNECT_ON_CLOSE,
|
|
&config->runtime_flags);
|
|
}
|
|
}
|
|
|
|
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) {
|
|
pr_err("socks must be embedded in a SOCK_ITEM attr\n");
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX,
|
|
attr,
|
|
nbd_sock_policy,
|
|
info->extack);
|
|
if (ret != 0) {
|
|
pr_err("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);
|
|
if (ret)
|
|
goto out;
|
|
if (info->attrs[NBD_ATTR_BACKEND_IDENTIFIER]) {
|
|
nbd->backend = nla_strdup(info->attrs[NBD_ATTR_BACKEND_IDENTIFIER],
|
|
GFP_KERNEL);
|
|
if (!nbd->backend) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
ret = device_create_file(disk_to_dev(nbd->disk), &backend_attr);
|
|
if (ret) {
|
|
dev_err(disk_to_dev(nbd->disk),
|
|
"device_create_file failed for backend!\n");
|
|
goto out;
|
|
}
|
|
set_bit(NBD_RT_HAS_BACKEND_FILE, &config->runtime_flags);
|
|
out:
|
|
mutex_unlock(&nbd->config_lock);
|
|
if (!ret) {
|
|
set_bit(NBD_RT_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 void nbd_disconnect_and_put(struct nbd_device *nbd)
|
|
{
|
|
mutex_lock(&nbd->config_lock);
|
|
nbd_disconnect(nbd);
|
|
sock_shutdown(nbd);
|
|
wake_up(&nbd->config->conn_wait);
|
|
/*
|
|
* Make sure recv thread has finished, we can safely call nbd_clear_que()
|
|
* to cancel the inflight I/Os.
|
|
*/
|
|
flush_workqueue(nbd->recv_workq);
|
|
nbd_clear_que(nbd);
|
|
nbd->task_setup = NULL;
|
|
mutex_unlock(&nbd->config_lock);
|
|
|
|
if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF,
|
|
&nbd->config->runtime_flags))
|
|
nbd_config_put(nbd);
|
|
}
|
|
|
|
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]) {
|
|
pr_err("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);
|
|
pr_err("couldn't find device at index %d\n", index);
|
|
return -EINVAL;
|
|
}
|
|
if (!refcount_inc_not_zero(&nbd->refs)) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
pr_err("device at index %d is going down\n", index);
|
|
return -EINVAL;
|
|
}
|
|
mutex_unlock(&nbd_index_mutex);
|
|
if (!refcount_inc_not_zero(&nbd->config_refs))
|
|
goto put_nbd;
|
|
nbd_disconnect_and_put(nbd);
|
|
nbd_config_put(nbd);
|
|
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 = 0;
|
|
bool put_dev = false;
|
|
|
|
if (!netlink_capable(skb, CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (!info->attrs[NBD_ATTR_INDEX]) {
|
|
pr_err("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);
|
|
pr_err("couldn't find a device at index %d\n", index);
|
|
return -EINVAL;
|
|
}
|
|
if (nbd->backend) {
|
|
if (info->attrs[NBD_ATTR_BACKEND_IDENTIFIER]) {
|
|
if (nla_strcmp(info->attrs[NBD_ATTR_BACKEND_IDENTIFIER],
|
|
nbd->backend)) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
dev_err(nbd_to_dev(nbd),
|
|
"backend image doesn't match with %s\n",
|
|
nbd->backend);
|
|
return -EINVAL;
|
|
}
|
|
} else {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
dev_err(nbd_to_dev(nbd), "must specify backend\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (!refcount_inc_not_zero(&nbd->refs)) {
|
|
mutex_unlock(&nbd_index_mutex);
|
|
pr_err("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_RT_BOUND, &config->runtime_flags) ||
|
|
!nbd->pid) {
|
|
dev_err(nbd_to_dev(nbd),
|
|
"not configured, cannot reconfigure\n");
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
ret = nbd_genl_size_set(info, nbd);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (info->attrs[NBD_ATTR_TIMEOUT])
|
|
nbd_set_cmd_timeout(nbd,
|
|
nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]));
|
|
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,
|
|
&nbd->flags))
|
|
put_dev = true;
|
|
} else {
|
|
if (test_and_clear_bit(NBD_DESTROY_ON_DISCONNECT,
|
|
&nbd->flags))
|
|
refcount_inc(&nbd->refs);
|
|
}
|
|
|
|
if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
|
|
set_bit(NBD_RT_DISCONNECT_ON_CLOSE,
|
|
&config->runtime_flags);
|
|
} else {
|
|
clear_bit(NBD_RT_DISCONNECT_ON_CLOSE,
|
|
&config->runtime_flags);
|
|
}
|
|
}
|
|
|
|
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) {
|
|
pr_err("socks must be embedded in a SOCK_ITEM attr\n");
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX,
|
|
attr,
|
|
nbd_sock_policy,
|
|
info->extack);
|
|
if (ret != 0) {
|
|
pr_err("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_small_ops nbd_connect_genl_ops[] = {
|
|
{
|
|
.cmd = NBD_CMD_CONNECT,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = nbd_genl_connect,
|
|
},
|
|
{
|
|
.cmd = NBD_CMD_DISCONNECT,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = nbd_genl_disconnect,
|
|
},
|
|
{
|
|
.cmd = NBD_CMD_RECONFIGURE,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = nbd_genl_reconfigure,
|
|
},
|
|
{
|
|
.cmd = NBD_CMD_STATUS,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.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,
|
|
.small_ops = nbd_connect_genl_ops,
|
|
.n_small_ops = ARRAY_SIZE(nbd_connect_genl_ops),
|
|
.resv_start_op = NBD_CMD_STATUS + 1,
|
|
.maxattr = NBD_ATTR_MAX,
|
|
.policy = nbd_attr_policy,
|
|
.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_noflag(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_noflag(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);
|
|
ret = genlmsg_reply(reply, info);
|
|
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) {
|
|
pr_err("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;
|
|
|
|
if (register_blkdev(NBD_MAJOR, "nbd"))
|
|
return -EIO;
|
|
|
|
nbd_del_wq = alloc_workqueue("nbd-del", WQ_UNBOUND, 0);
|
|
if (!nbd_del_wq) {
|
|
unregister_blkdev(NBD_MAJOR, "nbd");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (genl_register_family(&nbd_genl_family)) {
|
|
destroy_workqueue(nbd_del_wq);
|
|
unregister_blkdev(NBD_MAJOR, "nbd");
|
|
return -EINVAL;
|
|
}
|
|
nbd_dbg_init();
|
|
|
|
for (i = 0; i < nbds_max; i++)
|
|
nbd_dev_add(i, 1);
|
|
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;
|
|
|
|
/* Skip nbd that is being removed asynchronously */
|
|
if (refcount_read(&nbd->refs))
|
|
list_add_tail(&nbd->list, list);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit nbd_cleanup(void)
|
|
{
|
|
struct nbd_device *nbd;
|
|
LIST_HEAD(del_list);
|
|
|
|
/*
|
|
* Unregister netlink interface prior to waiting
|
|
* for the completion of netlink commands.
|
|
*/
|
|
genl_unregister_family(&nbd_genl_family);
|
|
|
|
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->config_refs))
|
|
pr_err("possibly leaking nbd_config (ref %d)\n",
|
|
refcount_read(&nbd->config_refs));
|
|
if (refcount_read(&nbd->refs) != 1)
|
|
pr_err("possibly leaking a device\n");
|
|
nbd_put(nbd);
|
|
}
|
|
|
|
/* Also wait for nbd_dev_remove_work() completes */
|
|
destroy_workqueue(nbd_del_wq);
|
|
|
|
idr_destroy(&nbd_index_idr);
|
|
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)");
|