diff options
| -rw-r--r-- | fs/ocfs2/stack_user.c | 222 |
1 files changed, 173 insertions, 49 deletions
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c index a5e58e2b9d5..43e6105369c 100644 --- a/fs/ocfs2/stack_user.c +++ b/fs/ocfs2/stack_user.c @@ -40,8 +40,18 @@ * unknown, -EINVAL is returned. Once the negotiation is complete, the * client can start sending messages. * - * The T01 protocol only has one message, "DOWN". It has the following - * syntax: + * The T01 protocol only has two 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. + * + * Once the local node number has been set, 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> * @@ -58,11 +68,18 @@ */ #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_VALID (2) -#define OCFS2_CONTROL_MESSAGE_DOWN "DOWN" -#define OCFS2_CONTROL_MESSAGE_DOWN_LEN 4 +#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_DOWN_OP "DOWN" #define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47 #define OCFS2_TEXT_UUID_LEN 32 #define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8 @@ -79,9 +96,35 @@ struct ocfs2_live_connection { struct ocfs2_control_private { struct list_head op_list; int op_state; + int op_this_node; +}; + +/* 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; +}; + +/* 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_down u_down; }; static atomic_t ocfs2_control_opened; +static int ocfs2_control_this_node = -1; static LIST_HEAD(ocfs2_live_connection_list); static LIST_HEAD(ocfs2_control_private_list); @@ -166,38 +209,37 @@ static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c) kfree(c); } -static ssize_t ocfs2_control_cfu(void *target, size_t target_len, - const char __user *buf, size_t count) +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) + if ((count != target_len) || + (count > sizeof(union ocfs2_control_message))) return -EINVAL; if (copy_from_user(target, buf, target_len)) return -EFAULT; - return count; + return 0; } -static ssize_t ocfs2_control_validate_handshake(struct file *file, - const char __user *buf, - size_t count) +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 != count) + if (ret) return ret; if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN)) return -EINVAL; - atomic_inc(&ocfs2_control_opened); ocfs2_control_set_handshake_state(file, - OCFS2_CONTROL_HANDSHAKE_VALID); - + OCFS2_CONTROL_HANDSHAKE_PROTOCOL); return count; } @@ -219,45 +261,92 @@ static void ocfs2_control_send_down(const char *uuid, mutex_unlock(&ocfs2_control_lock); } -/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */ -struct ocfs2_control_message_down { - char tag[OCFS2_CONTROL_MESSAGE_DOWN_LEN]; - char space1; - char uuid[OCFS2_TEXT_UUID_LEN]; - char space2; - char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN]; - char newline; -}; +/* + * Called whenever configuration elements are sent to /dev/ocfs2_control. + * If all configuration elements are present, try to set the global + * values. If not, return -EAGAIN. If there is a problem, return a + * different error. + */ +static int ocfs2_control_install_private(struct file *file) +{ + int rc = 0; + int set_p = 1; + struct ocfs2_control_private *p = file->private_data; -static ssize_t ocfs2_control_message(struct file *file, - const char __user *buf, - size_t count) + BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL); + + if (p->op_this_node < 0) + set_p = 0; + + mutex_lock(&ocfs2_control_lock); + if (ocfs2_control_this_node < 0) { + if (set_p) + ocfs2_control_this_node = p->op_this_node; + } else if (ocfs2_control_this_node != p->op_this_node) + rc = -EINVAL; + 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_do_setnode_msg(struct file *file, + struct ocfs2_control_message_setn *msg) { - ssize_t ret; - char *p = NULL; long nodenum; - struct ocfs2_control_message_down msg; + char *ptr = NULL; + struct ocfs2_control_private *p = file->private_data; - /* Try to catch padding issues */ - WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) != - (sizeof(msg.tag) + sizeof(msg.space1))); + if (ocfs2_control_get_handshake_state(file) != + OCFS2_CONTROL_HANDSHAKE_PROTOCOL) + return -EINVAL; - memset(&msg, 0, sizeof(struct ocfs2_control_message_down)); - ret = ocfs2_control_cfu(&msg, OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN, - buf, count); - if (ret != count) - return ret; + 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_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, - strlen(OCFS2_CONTROL_MESSAGE_DOWN))) + if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP, + OCFS2_CONTROL_MESSAGE_OP_LEN)) return -EINVAL; - if ((msg.space1 != ' ') || (msg.space2 != ' ') || - (msg.newline != '\n')) + if ((msg->space1 != ' ') || (msg->space2 != ' ') || + (msg->newline != '\n')) return -EINVAL; - msg.space1 = msg.space2 = msg.newline = '\0'; + msg->space1 = msg->space2 = msg->newline = '\0'; - nodenum = simple_strtol(msg.nodestr, &p, 16); + nodenum = simple_strtol(msg->nodestr, &p, 16); if (!p || *p) return -EINVAL; @@ -265,9 +354,40 @@ static ssize_t ocfs2_control_message(struct file *file, (nodenum > INT_MAX) || (nodenum < 0)) return -ERANGE; - ocfs2_control_send_down(msg.uuid, nodenum); + ocfs2_control_send_down(msg->uuid, nodenum); - return count; + 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_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, @@ -283,10 +403,11 @@ static ssize_t ocfs2_control_write(struct file *file, break; case OCFS2_CONTROL_HANDSHAKE_READ: - ret = ocfs2_control_validate_handshake(file, buf, - count); + 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; @@ -350,6 +471,8 @@ static int ocfs2_control_release(struct inode *inode, struct file *file) "an emergency restart!\n"); emergency_restart(); } + /* Last valid close clears the node number */ + ocfs2_control_this_node = -1; } out: @@ -370,6 +493,7 @@ static int ocfs2_control_open(struct inode *inode, struct file *file) 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; |