From d4b95eef4dc4a59bcd42bdf783638a2eaa57b4c8 Mon Sep 17 00:00:00 2001 From: Joel Becker Date: Wed, 20 Feb 2008 15:39:44 -0800 Subject: ocfs2: Add the 'set version' message to the ocfs2_control device. 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. Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c index 43e6105..de982c1 100644 --- a/fs/ocfs2/stack_user.c +++ b/fs/ocfs2/stack_user.c @@ -40,7 +40,7 @@ * unknown, -EINVAL is returned. Once the negotiation is complete, the * client can start sending messages. * - * The T01 protocol only has two messages. First is the "SETN" message. + * The T01 protocol has three messages. First is the "SETN" message. * It has the following syntax: * * SETN<8-char-hex-nodenum> @@ -50,8 +50,22 @@ * 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: + * 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 + * user_stack.sp_proto->lp_max_version.pv_major, and the minor number + * must be less than or equal to ...->lp_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> * @@ -79,9 +93,12 @@ #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 /* @@ -97,6 +114,7 @@ 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> */ @@ -107,6 +125,16 @@ struct ocfs2_control_message_setn { 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]; @@ -120,11 +148,13 @@ struct ocfs2_control_message_down { 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 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); @@ -264,8 +294,9 @@ static void ocfs2_control_send_down(const char *uuid, /* * 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. + * 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) { @@ -275,15 +306,32 @@ static int ocfs2_control_install_private(struct file *file) BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL); - if (p->op_this_node < 0) + 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; + } - 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) + 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) { @@ -327,6 +375,56 @@ static int ocfs2_control_do_setnode_msg(struct file *file, 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 = + &user_stack.sp_proto->lp_max_version; + + 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) { @@ -379,6 +477,10 @@ static ssize_t ocfs2_control_message(struct file *file, !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)) @@ -471,8 +573,13 @@ static int ocfs2_control_release(struct inode *inode, struct file *file) "an emergency restart!\n"); emergency_restart(); } - /* Last valid close clears the node number */ + /* + * 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_major = 0; } out: -- cgit v0.10.2