/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * stack_user.c * * Code which interfaces ocfs2 with fs/dlm and a userspace stack. * * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License as published by the Free Software Foundation, version 2. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */ #include #include #include #include #include #include #include #include #include "stackglue.h" #include /* * The control protocol starts with a handshake. Until the handshake * is complete, the control device will fail all write(2)s. * * The handshake is simple. First, the client reads until EOF. Each line * of output is a supported protocol tag. All protocol tags are a single * character followed by a two hex digit version number. Currently the * only things supported is T01, for "Text-base version 0x01". Next, the * client writes the version they would like to use, including the newline. * Thus, the protocol tag is 'T01\n'. If the version tag written is * unknown, -EINVAL is returned. Once the negotiation is complete, the * client can start sending messages. * * The T01 protocol has three messages. First is the "SETN" message. * It has the following syntax: * * SETN<8-char-hex-nodenum> * * This is 14 characters. * * The "SETN" message must be the first message following the protocol. * It tells ocfs2_control the local node number. * * Next comes the "SETV" message. It has the following syntax: * * SETV<2-char-hex-major><2-char-hex-minor> * * This is 11 characters. * * The "SETV" message sets the filesystem locking protocol version as * negotiated by the client. The client negotiates based on the maximum * version advertised in /sys/fs/ocfs2/max_locking_protocol. The major * number from the "SETV" message must match * ocfs2_user_plugin.sp_max_proto.pv_major, and the minor number * must be less than or equal to ...sp_max_version.pv_minor. * * Once this information has been set, mounts will be allowed. From this * point on, the "DOWN" message can be sent for node down notification. * It has the following syntax: * * DOWN<32-char-cap-hex-uuid><8-char-hex-nodenum> * * eg: * * DOWN 632A924FDD844190BDA93C0DF6B94899 00000001\n * * This is 47 characters. */ /* * Whether or not the client has done the handshake. * For now, we have just one protocol version. */ #define OCFS2_CONTROL_PROTO "T01\n" #define OCFS2_CONTROL_PROTO_LEN 4 /* Handshake states */ #define OCFS2_CONTROL_HANDSHAKE_INVALID (0) #define OCFS2_CONTROL_HANDSHAKE_READ (1) #define OCFS2_CONTROL_HANDSHAKE_PROTOCOL (2) #define OCFS2_CONTROL_HANDSHAKE_VALID (3) /* Messages */ #define OCFS2_CONTROL_MESSAGE_OP_LEN 4 #define OCFS2_CONTROL_MESSAGE_SETNODE_OP "SETN" #define OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN 14 #define OCFS2_CONTROL_MESSAGE_SETVERSION_OP "SETV" #define OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN 11 #define OCFS2_CONTROL_MESSAGE_DOWN_OP "DOWN" #define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47 #define OCFS2_TEXT_UUID_LEN 32 #define OCFS2_CONTROL_MESSAGE_VERNUM_LEN 2 #define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8 #define VERSION_LOCK "version_lock" enum ocfs2_connection_type { WITH_CONTROLD, NO_CONTROLD }; /* * ocfs2_live_connection is refcounted because the filesystem and * miscdevice sides can detach in different order. Let's just be safe. */ struct ocfs2_live_connection { struct list_head oc_list; struct ocfs2_cluster_connection *oc_conn; enum ocfs2_connection_type oc_type; atomic_t oc_this_node; int oc_our_slot; struct dlm_lksb oc_version_lksb; char oc_lvb[DLM_LVB_LEN]; struct completion oc_sync_wait; wait_queue_head_t oc_wait; }; struct ocfs2_control_private { struct list_head op_list; int op_state; int op_this_node; struct ocfs2_protocol_version op_proto; }; /* SETN<8-char-hex-nodenum> */ struct ocfs2_control_message_setn { char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; char space; char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN]; char newline; }; /* SETV<2-char-hex-major><2-char-hex-minor> */ struct ocfs2_control_message_setv { char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; char space1; char major[OCFS2_CONTROL_MESSAGE_VERNUM_LEN]; char space2; char minor[OCFS2_CONTROL_MESSAGE_VERNUM_LEN]; char newline; }; /* DOWN<32-char-cap-hex-uuid><8-char-hex-nodenum> */ struct ocfs2_control_message_down { char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; char space1; char uuid[OCFS2_TEXT_UUID_LEN]; char space2; char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN]; char newline; }; union ocfs2_control_message { char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; struct ocfs2_control_message_setn u_setn; struct ocfs2_control_message_setv u_setv; struct ocfs2_control_message_down u_down; }; static struct ocfs2_stack_plugin ocfs2_user_plugin; static atomic_t ocfs2_control_opened; static int ocfs2_control_this_node = -1; static struct ocfs2_protocol_version running_proto; static LIST_HEAD(ocfs2_live_connection_list); static LIST_HEAD(ocfs2_control_private_list); static DEFINE_MUTEX(ocfs2_control_lock); static inline void ocfs2_control_set_handshake_state(struct file *file, int state) { struct ocfs2_control_private *p = file->private_data; p->op_state = state; } static inline int ocfs2_control_get_handshake_state(struct file *file) { struct ocfs2_control_private *p = file->private_data; return p->op_state; } static struct ocfs2_live_connection *ocfs2_connection_find(const char *name) { size_t len = strlen(name); struct ocfs2_live_connection *c; BUG_ON(!mutex_is_locked(&ocfs2_control_lock)); list_for_each_entry(c, &ocfs2_live_connection_list, oc_list) { if ((c->oc_conn->cc_namelen == len) && !strncmp(c->oc_conn->cc_name, name, len)) return c; } return NULL; } /* * ocfs2_live_connection structures are created underneath the ocfs2 * mount path. Since the VFS prevents multiple calls to * fill_super(), we can't get dupes here. */ static int ocfs2_live_connection_attach(struct ocfs2_cluster_connection *conn, struct ocfs2_live_connection *c) { int rc = 0; mutex_lock(&ocfs2_control_lock); c->oc_conn = conn; if ((c->oc_type == NO_CONTROLD) || atomic_read(&ocfs2_control_opened)) list_add(&c->oc_list, &ocfs2_live_connection_list); else { printk(KERN_ERR "ocfs2: Userspace control daemon is not present\n"); rc = -ESRCH; } mutex_unlock(&ocfs2_control_lock); return rc; } /* * This function disconnects the cluster connection from ocfs2_control. * Afterwards, userspace can't affect the cluster connection. */ static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c) { mutex_lock(&ocfs2_control_lock); list_del_init(&c->oc_list); c->oc_conn = NULL; mutex_unlock(&ocfs2_control_lock); kfree(c); } static int ocfs2_control_cfu(void *target, size_t target_len, const char __user *buf, size_t count) { /* The T01 expects write(2) calls to have exactly one command */ if ((count != target_len) || (count > sizeof(union ocfs2_control_message))) return -EINVAL; if (copy_from_user(target, buf, target_len)) return -EFAULT; return 0; } static ssize_t ocfs2_control_validate_protocol(struct file *file, const char __user *buf, size_t count) { ssize_t ret; char kbuf[OCFS2_CONTROL_PROTO_LEN]; ret = ocfs2_control_cfu(kbuf, OCFS2_CONTROL_PROTO_LEN, buf, count); if (ret) return ret; if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN)) return -EINVAL; ocfs2_control_set_handshake_state(file, OCFS2_CONTROL_HANDSHAKE_PROTOCOL); return count; } static void ocfs2_control_send_down(const char *uuid, int nodenum) { struct ocfs2_live_connection *c; mutex_lock(&ocfs2_control_lock); c = ocfs2_connection_find(uuid); if (c) { BUG_ON(c->oc_conn == NULL); c->oc_conn->cc_recovery_handler(nodenum, c->oc_conn->cc_recovery_data); } mutex_unlock(&ocfs2_control_lock); } /* * Called whenever configuration elements are sent to /dev/ocfs2_control. * If all configuration elements are present, try to set the global * values. If there is a problem, return an error. Skip any missing * elements, and only bump ocfs2_control_opened when we have all elements * and are successful. */ static int ocfs2_control_install_private(struct file *file) { int rc = 0; int set_p = 1; struct ocfs2_control_private *p = file->private_data; BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL); mutex_lock(&ocfs2_control_lock); if (p->op_this_node < 0) { set_p = 0; } else if ((ocfs2_control_this_node >= 0) && (ocfs2_control_this_node != p->op_this_node)) { rc = -EINVAL; goto out_unlock; } if (!p->op_proto.pv_major) { set_p = 0; } else if (!list_empty(&ocfs2_live_connection_list) && ((running_proto.pv_major != p->op_proto.pv_major) || (running_proto.pv_minor != p->op_proto.pv_minor))) { rc = -EINVAL; goto out_unlock; } if (set_p) { ocfs2_control_this_node = p->op_this_node; running_proto.pv_major = p->op_proto.pv_major; running_proto.pv_minor = p->op_proto.pv_minor; } out_unlock: mutex_unlock(&ocfs2_control_lock); if (!rc && set_p) { /* We set the global values successfully */ atomic_inc(&ocfs2_control_opened); ocfs2_control_set_handshake_state(file, OCFS2_CONTROL_HANDSHAKE_VALID); } return rc; } static int ocfs2_control_get_this_node(void) { int rc; mutex_lock(&ocfs2_control_lock); if (ocfs2_control_this_node < 0) rc = -EINVAL; else rc = ocfs2_control_this_node; mutex_unlock(&ocfs2_control_lock); return rc; } static int ocfs2_control_do_setnode_msg(struct file *file, struct ocfs2_control_message_setn *msg) { long nodenum; char *ptr = NULL; struct ocfs2_control_private *p = file->private_data; if (ocfs2_control_get_handshake_state(file) != OCFS2_CONTROL_HANDSHAKE_PROTOCOL) return -EINVAL; if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP, OCFS2_CONTROL_MESSAGE_OP_LEN)) return -EINVAL; if ((msg->space != ' ') || (msg->newline != '\n')) return -EINVAL; msg->space = msg->newline = '\0'; nodenum = simple_strtol(msg->nodestr, &ptr, 16); if (!ptr || *ptr) return -EINVAL; if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) || (nodenum > INT_MAX) || (nodenum < 0)) return -ERANGE; p->op_this_node = nodenum; return ocfs2_control_install_private(file); } static int ocfs2_control_do_setversion_msg(struct file *file, struct ocfs2_control_message_setv *msg) { long major, minor; char *ptr = NULL; struct ocfs2_control_private *p = file->private_data; struct ocfs2_protocol_version *max = &ocfs2_user_plugin.sp_max_proto; if (ocfs2_control_get_handshake_state(file) != OCFS2_CONTROL_HANDSHAKE_PROTOCOL) return -EINVAL; if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP, OCFS2_CONTROL_MESSAGE_OP_LEN)) return -EINVAL; if ((msg->space1 != ' ') || (msg->space2 != ' ') || (msg->newline != '\n')) return -EINVAL; msg->space1 = msg->space2 = msg->newline = '\0'; major = simple_strtol(msg->major, &ptr, 16); if (!ptr || *ptr) return -EINVAL; minor = simple_strtol(msg->minor, &ptr, 16); if (!ptr || *ptr) return -EINVAL; /* * The major must be between 1 and 255, inclusive. The minor * must be between 0 and 255, inclusive. The version passed in * must be within the maximum version supported by the filesystem. */ if ((major == LONG_MIN) || (major == LONG_MAX) || (major > (u8)-1) || (major < 1)) return -ERANGE; if ((minor == LONG_MIN) || (minor == LONG_MAX) || (minor > (u8)-1) || (minor < 0)) return -ERANGE; if ((major != max->pv_major) || (minor > max->pv_minor)) return -EINVAL; p->op_proto.pv_major = major; p->op_proto.pv_minor = minor; return ocfs2_control_install_private(file); } static int ocfs2_control_do_down_msg(struct file *file, struct ocfs2_control_message_down *msg) { long nodenum; char *p = NULL; if (ocfs2_control_get_handshake_state(file) != OCFS2_CONTROL_HANDSHAKE_VALID) return -EINVAL; if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP, OCFS2_CONTROL_MESSAGE_OP_LEN)) return -EINVAL; if ((msg->space1 != ' ') || (msg->space2 != ' ') || (msg->newline != '\n')) return -EINVAL; msg->space1 = msg->space2 = msg->newline = '\0'; nodenum = simple_strtol(msg->nodestr, &p, 16); if (!p || *p) return -EINVAL; if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) || (nodenum > INT_MAX) || (nodenum < 0)) return -ERANGE; ocfs2_control_send_down(msg->uuid, nodenum); return 0; } static ssize_t ocfs2_control_message(struct file *file, const char __user *buf, size_t count) { ssize_t ret; union ocfs2_control_message msg; /* Try to catch padding issues */ WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) != (sizeof(msg.u_down.tag) + sizeof(msg.u_down.space1))); memset(&msg, 0, sizeof(union ocfs2_control_message)); ret = ocfs2_control_cfu(&msg, count, buf, count); if (ret) goto out; if ((count == OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN) && !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP, OCFS2_CONTROL_MESSAGE_OP_LEN)) ret = ocfs2_control_do_setnode_msg(file, &msg.u_setn); else if ((count == OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN) && !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP, OCFS2_CONTROL_MESSAGE_OP_LEN)) ret = ocfs2_control_do_setversion_msg(file, &msg.u_setv); else if ((count == OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN) && !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN_OP, OCFS2_CONTROL_MESSAGE_OP_LEN)) ret = ocfs2_control_do_down_msg(file, &msg.u_down); else ret = -EINVAL; out: return ret ? ret : count; } static ssize_t ocfs2_control_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { ssize_t ret; switch (ocfs2_control_get_handshake_state(file)) { case OCFS2_CONTROL_HANDSHAKE_INVALID: ret = -EINVAL; break; case OCFS2_CONTROL_HANDSHAKE_READ: ret = ocfs2_control_validate_protocol(file, buf, count); break; case OCFS2_CONTROL_HANDSHAKE_PROTOCOL: case OCFS2_CONTROL_HANDSHAKE_VALID: ret = ocfs2_control_message(file, buf, count); break; default: BUG(); ret = -EIO; break; } return ret; } /* * This is a naive version. If we ever have a new protocol, we'll expand * it. Probably using seq_file. */ static ssize_t ocfs2_control_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { ssize_t ret; ret = simple_read_from_buffer(buf, count, ppos, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN); /* Have we read the whole protocol list? */ if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN) ocfs2_control_set_handshake_state(file, OCFS2_CONTROL_HANDSHAKE_READ); return ret; } static int ocfs2_control_release(struct inode *inode, struct file *file) { struct ocfs2_control_private *p = file->private_data; mutex_lock(&ocfs2_control_lock); if (ocfs2_control_get_handshake_state(file) != OCFS2_CONTROL_HANDSHAKE_VALID) goto out; if (atomic_dec_and_test(&ocfs2_control_opened)) { if (!list_empty(&ocfs2_live_connection_list)) { /* XXX: Do bad things! */ printk(KERN_ERR "ocfs2: Unexpected release of ocfs2_control!\n" " Loss of cluster connection requires " "an emergency restart!\n"); emergency_restart(); } /* * Last valid close clears the node number and resets * the locking protocol version */ ocfs2_control_this_node = -1; running_proto.pv_major = 0; running_proto.pv_minor = 0; } out: list_del_init(&p->op_list); file->private_data = NULL; mutex_unlock(&ocfs2_control_lock); kfree(p); return 0; } static int ocfs2_control_open(struct inode *inode, struct file *file) { struct ocfs2_control_private *p; p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL); if (!p) return -ENOMEM; p->op_this_node = -1; mutex_lock(&ocfs2_control_lock); file->private_data = p; list_add(&p->op_list, &ocfs2_control_private_list); mutex_unlock(&ocfs2_control_lock); return 0; } static const struct file_operations ocfs2_control_fops = { .open = ocfs2_control_open, .release = ocfs2_control_release, .read = ocfs2_control_read, .write = ocfs2_control_write, .owner = THIS_MODULE, .llseek = default_llseek, }; static struct miscdevice ocfs2_control_device = { .minor = MISC_DYNAMIC_MINOR, .name = "ocfs2_control", .fops = &ocfs2_control_fops, }; static int ocfs2_control_init(void) { int rc; atomic_set(&ocfs2_control_opened, 0); rc = misc_register(&ocfs2_control_device); if (rc) printk(KERN_ERR "ocfs2: Unable to register ocfs2_control device " "(errno %d)\n", -rc); return rc; } static void ocfs2_control_exit(void) { int rc; rc = misc_deregister(&ocfs2_control_device); if (rc) printk(KERN_ERR "ocfs2: Unable to deregister ocfs2_control device " "(errno %d)\n", -rc); } static void fsdlm_lock_ast_wrapper(void *astarg) { struct ocfs2_dlm_lksb *lksb = astarg; int status = lksb->lksb_fsdlm.sb_status; /* * For now we're punting on the issue of other non-standard errors * where we can't tell if the unlock_ast or lock_ast should be called. * The main "other error" that's possible is EINVAL which means the * function was called with invalid args, which shouldn't be possible * since the caller here is under our control. Other non-standard * errors probably fall into the same category, or otherwise are fatal * which means we can't carry on anyway. */ if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL) lksb->lksb_conn->cc_proto->lp_unlock_ast(lksb, 0); else lksb->lksb_conn->cc_proto->lp_lock_ast(lksb); } static void fsdlm_blocking_ast_wrapper(void *astarg, int level) { struct ocfs2_dlm_lksb *lksb = astarg; lksb->lksb_conn->cc_proto->lp_blocking_ast(lksb, level); } static int user_dlm_lock(struct ocfs2_cluster_connection *conn, int mode, struct ocfs2_dlm_lksb *lksb, u32 flags, void *name, unsigned int namelen) { int ret; if (!lksb->lksb_fsdlm.sb_lvbptr) lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb + sizeof(struct dlm_lksb); ret = dlm_lock(conn->cc_lockspace, mode, &lksb->lksb_fsdlm, flags|DLM_LKF_NODLCKWT, name, namelen, 0, fsdlm_lock_ast_wrapper, lksb, fsdlm_blocking_ast_wrapper); return ret; } static int user_dlm_unlock(struct ocfs2_cluster_connection *conn, struct ocfs2_dlm_lksb *lksb, u32 flags) { int ret; ret = dlm_unlock(conn->cc_lockspace, lksb->lksb_fsdlm.sb_lkid, flags, &lksb->lksb_fsdlm, lksb); return ret; } static int user_dlm_lock_status(struct ocfs2_dlm_lksb *lksb) { return lksb->lksb_fsdlm.sb_status; } static int user_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb) { int invalid = lksb->lksb_fsdlm.sb_flags & DLM_SBF_VALNOTVALID; return !invalid; } static void *user_dlm_lvb(struct ocfs2_dlm_lksb *lksb) { if (!lksb->lksb_fsdlm.sb_lvbptr) lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb + sizeof(struct dlm_lksb); return (void *)(lksb->lksb_fsdlm.sb_lvbptr); } static void user_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb) { } static int user_plock(struct ocfs2_cluster_connection *conn, u64 ino, struct file *file, int cmd, struct file_lock *fl) { /* * This more or less just demuxes the plock request into any * one of three dlm calls. * * Internally, fs/dlm will pass these to a misc device, which * a userspace daemon will read and write to. * * For now, cancel requests (which happen internally only), * are turned into unlocks. Most of this function taken from * gfs2_lock. */ if (cmd == F_CANCELLK) { cmd = F_SETLK; fl->fl_type = F_UNLCK; } if (IS_GETLK(cmd)) return dlm_posix_get(conn->cc_lockspace, ino, file, fl); else if (fl->fl_type == F_UNLCK) return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl); else return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl); } /* * Compare a requested locking protocol version against the current one. * * If the major numbers are different, they are incompatible. * If the current minor is greater than the request, they are incompatible. * If the current minor is less than or equal to the request, they are * compatible, and the requester should run at the current minor version. */ static int fs_protocol_compare(struct ocfs2_protocol_version *existing, struct ocfs2_protocol_version *request) { if (existing->pv_major != request->pv_major) return 1; if (existing->pv_minor > request->pv_minor) return 1; if (existing->pv_minor < request->pv_minor) request->pv_minor = existing->pv_minor; return 0; } static void lvb_to_version(char *lvb, struct ocfs2_protocol_version *ver) { struct ocfs2_protocol_version *pv = (struct ocfs2_protocol_version *)lvb; /* * ocfs2_protocol_version has two u8 variables, so we don't * need any endian conversion. */ ver->pv_major = pv->pv_major; ver->pv_minor = pv->pv_minor; } static void version_to_lvb(struct ocfs2_protocol_version *ver, char *lvb) { struct ocfs2_protocol_version *pv = (struct ocfs2_protocol_version *)lvb; /* * ocfs2_protocol_version has two u8 variables, so we don't * need any endian conversion. */ pv->pv_major = ver->pv_major; pv->pv_minor = ver->pv_minor; } static void sync_wait_cb(void *arg) { struct ocfs2_cluster_connection *conn = arg; struct ocfs2_live_connection *lc = conn->cc_private; complete(&lc->oc_sync_wait); } static int sync_unlock(struct ocfs2_cluster_connection *conn, struct dlm_lksb *lksb, char *name) { int error; struct ocfs2_live_connection *lc = conn->cc_private; error = dlm_unlock(conn->cc_lockspace, lksb->sb_lkid, 0, lksb, conn); if (error) { printk(KERN_ERR "%s lkid %x error %d\n", name, lksb->sb_lkid, error); return error; } wait_for_completion(&lc->oc_sync_wait); if (lksb->sb_status != -DLM_EUNLOCK) { printk(KERN_ERR "%s lkid %x status %d\n", name, lksb->sb_lkid, lksb->sb_status); return -1; } return 0; } static int sync_lock(struct ocfs2_cluster_connection *conn, int mode, uint32_t flags, struct dlm_lksb *lksb, char *name) { int error, status; struct ocfs2_live_connection *lc = conn->cc_private; error = dlm_lock(conn->cc_lockspace, mode, lksb, flags, name, strlen(name), 0, sync_wait_cb, conn, NULL); if (error) { printk(KERN_ERR "%s lkid %x flags %x mode %d error %d\n", name, lksb->sb_lkid, flags, mode, error); return error; } wait_for_completion(&lc->oc_sync_wait); status = lksb->sb_status; if (status && status != -EAGAIN) { printk(KERN_ERR "%s lkid %x flags %x mode %d status %d\n", name, lksb->sb_lkid, flags, mode, status); } return status; } static int version_lock(struct ocfs2_cluster_connection *conn, int mode, int flags) { struct ocfs2_live_connection *lc = conn->cc_private; return sync_lock(conn, mode, flags, &lc->oc_version_lksb, VERSION_LOCK); } static int version_unlock(struct ocfs2_cluster_connection *conn) { struct ocfs2_live_connection *lc = conn->cc_private; return sync_unlock(conn, &lc->oc_version_lksb, VERSION_LOCK); } /* get_protocol_version() * * To exchange ocfs2 versioning, we use the LVB of the version dlm lock. * The algorithm is: * 1. Attempt to take the lock in EX mode (non-blocking). * 2. If successful (which means it is the first mount), write the * version number and downconvert to PR lock. * 3. If unsuccessful (returns -EAGAIN), read the version from the LVB after * taking the PR lock. */ static int get_protocol_version(struct ocfs2_cluster_connection *conn) { int ret; struct ocfs2_live_connection *lc = conn->cc_private; struct ocfs2_protocol_version pv; running_proto.pv_major = ocfs2_user_plugin.sp_max_proto.pv_major; running_proto.pv_minor = ocfs2_user_plugin.sp_max_proto.pv_minor; lc->oc_version_lksb.sb_lvbptr = lc->oc_lvb; ret = version_lock(conn, DLM_LOCK_EX, DLM_LKF_VALBLK|DLM_LKF_NOQUEUE); if (!ret) { conn->cc_version.pv_major = running_proto.pv_major; conn->cc_version.pv_minor = running_proto.pv_minor; version_to_lvb(&running_proto, lc->oc_lvb); version_lock(conn, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_VALBLK); } else if (ret == -EAGAIN) { ret = version_lock(conn, DLM_LOCK_PR, DLM_LKF_VALBLK); if (ret) goto out; lvb_to_version(lc->oc_lvb, &pv); if ((pv.pv_major != running_proto.pv_major) || (pv.pv_minor > running_proto.pv_minor)) { ret = -EINVAL; goto out; } conn->cc_version.pv_major = pv.pv_major; conn->cc_version.pv_minor = pv.pv_minor; } out: return ret; } static void user_recover_prep(void *arg) { } static void user_recover_slot(void *arg, struct dlm_slot *slot) { struct ocfs2_cluster_connection *conn = arg; printk(KERN_INFO "ocfs2: Node %d/%d down. Initiating recovery.\n", slot->nodeid, slot->slot); conn->cc_recovery_handler(slot->nodeid, conn->cc_recovery_data); } static void user_recover_done(void *arg, struct dlm_slot *slots, int num_slots, int our_slot, uint32_t generation) { struct ocfs2_cluster_connection *conn = arg; struct ocfs2_live_connection *lc = conn->cc_private; int i; for (i = 0; i < num_slots; i++) if (slots[i].slot == our_slot) { atomic_set(&lc->oc_this_node, slots[i].nodeid); break; } lc->oc_our_slot = our_slot; wake_up(&lc->oc_wait); } static const struct dlm_lockspace_ops ocfs2_ls_ops = { .recover_prep = user_recover_prep, .recover_slot = user_recover_slot, .recover_done = user_recover_done, }; static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn) { version_unlock(conn); dlm_release_lockspace(conn->cc_lockspace, 2); conn->cc_lockspace = NULL; ocfs2_live_connection_drop(conn->cc_private); conn->cc_private = NULL; return 0; } static int user_cluster_connect(struct ocfs2_cluster_connection *conn) { dlm_lockspace_t *fsdlm; struct ocfs2_live_connection *lc; int rc, ops_rv; BUG_ON(conn == NULL); lc = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL); if (!lc) { rc = -ENOMEM; goto out; } init_waitqueue_head(&lc->oc_wait); init_completion(&lc->oc_sync_wait); atomic_set(&lc->oc_this_node, 0); conn->cc_private = lc; lc->oc_type = NO_CONTROLD; rc = dlm_new_lockspace(conn->cc_name, conn->cc_cluster_name, DLM_LSFL_FS, DLM_LVB_LEN, &ocfs2_ls_ops, conn, &ops_rv, &fsdlm); if (rc) goto out; if (ops_rv == -EOPNOTSUPP) { lc->oc_type = WITH_CONTROLD; printk(KERN_NOTICE "ocfs2: You seem to be using an older " "version of dlm_controld and/or ocfs2-tools." " Please consider upgrading.\n"); } else if (ops_rv) { rc = ops_rv; goto out; } conn->cc_lockspace = fsdlm; rc = ocfs2_live_connection_attach(conn, lc); if (rc) goto out; if (lc->oc_type == NO_CONTROLD) { rc = get_protocol_version(conn); if (rc) { printk(KERN_ERR "ocfs2: Could not determine" " locking version\n"); user_cluster_disconnect(conn); goto out; } wait_event(lc->oc_wait, (atomic_read(&lc->oc_this_node) > 0)); } /* * running_proto must have been set before we allowed any mounts * to proceed. */ if (fs_protocol_compare(&running_proto, &conn->cc_version)) { printk(KERN_ERR "Unable to mount with fs locking protocol version " "%u.%u because negotiated protocol is %u.%u\n", conn->cc_version.pv_major, conn->cc_version.pv_minor, running_proto.pv_major, running_proto.pv_minor); rc = -EPROTO; ocfs2_live_connection_drop(lc); lc = NULL; } out: if (rc) kfree(lc); return rc; } static int user_cluster_this_node(struct ocfs2_cluster_connection *conn, unsigned int *this_node) { int rc; struct ocfs2_live_connection *lc = conn->cc_private; if (lc->oc_type == WITH_CONTROLD) rc = ocfs2_control_get_this_node(); else if (lc->oc_type == NO_CONTROLD) rc = atomic_read(&lc->oc_this_node); else rc = -EINVAL; if (rc < 0) return rc; *this_node = rc; return 0; } static struct ocfs2_stack_operations ocfs2_user_plugin_ops = { .connect = user_cluster_connect, .disconnect = user_cluster_disconnect, .this_node = user_cluster_this_node, .dlm_lock = user_dlm_lock, .dlm_unlock = user_dlm_unlock, .lock_status = user_dlm_lock_status, .lvb_valid = user_dlm_lvb_valid, .lock_lvb = user_dlm_lvb, .plock = user_plock, .dump_lksb = user_dlm_dump_lksb, }; static struct ocfs2_stack_plugin ocfs2_user_plugin = { .sp_name = "user", .sp_ops = &ocfs2_user_plugin_ops, .sp_owner = THIS_MODULE, }; static int __init ocfs2_user_plugin_init(void) { int rc; rc = ocfs2_control_init(); if (!rc) { rc = ocfs2_stack_glue_register(&ocfs2_user_plugin); if (rc) ocfs2_control_exit(); } return rc; } static void __exit ocfs2_user_plugin_exit(void) { ocfs2_stack_glue_unregister(&ocfs2_user_plugin); ocfs2_control_exit(); } MODULE_AUTHOR("Oracle"); MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks"); MODULE_LICENSE("GPL"); module_init(ocfs2_user_plugin_init); module_exit(ocfs2_user_plugin_exit);