diff options
Diffstat (limited to 'fs/ocfs2/stack_user.c')
| -rw-r--r-- | fs/ocfs2/stack_user.c | 1134 |
1 files changed, 1134 insertions, 0 deletions
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c new file mode 100644 index 000000000..2768eb1da --- /dev/null +++ b/fs/ocfs2/stack_user.c @@ -0,0 +1,1134 @@ +/* -*- 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 <linux/module.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/reboot.h> +#include <linux/sched.h> +#include <asm/uaccess.h> + +#include "stackglue.h" + +#include <linux/dlm_plock.h> + +/* + * 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<space><8-char-hex-nodenum><newline> + * + * 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<space><2-char-hex-major><space><2-char-hex-minor><newline> + * + * 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<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> + * + * 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<space><8-char-hex-nodenum><newline> */ +struct ocfs2_control_message_setn { + char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; + char space; + char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN]; + char newline; +}; + +/* SETV<space><2-char-hex-major><space><2-char-hex-minor><newline> */ +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<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */ +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) + return -ENOMEM; + + 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); |