From: Joel Becker Date: Fri, 1 Feb 2008 23:03:57 +0000 (-0800) Subject: ocfs2: Break out stackglue into modules. X-Git-Tag: v2.6.26-rc1~1143^2~42 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=286eaa95c5c5915a6b72cc3f0a2534161fd7928b;p=linux-2.6 ocfs2: Break out stackglue into modules. We define the ocfs2_stack_plugin structure to represent a stack driver. The o2cb stack code is split into stack_o2cb.c. This becomes the ocfs2_stack_o2cb.ko module. The stackglue generic functions are similarly split into the ocfs2_stackglue.ko module. This module now provides an interface to register drivers. The ocfs2_stack_o2cb driver registers itself. As part of this interface, ocfs2_stackglue can load drivers on demand. This is accomplished in ocfs2_cluster_connect(). ocfs2_cluster_disconnect() is now notified when a _hangup() is pending. If a hangup is pending, it will not release the driver module and will let _hangup() do that. Signed-off-by: Joel Becker --- diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile index 8e86195fed..b734254329 100644 --- a/fs/ocfs2/Makefile +++ b/fs/ocfs2/Makefile @@ -2,7 +2,7 @@ EXTRA_CFLAGS += -Ifs/ocfs2 EXTRA_CFLAGS += -DCATCH_BH_JBD_RACES -obj-$(CONFIG_OCFS2_FS) += ocfs2.o +obj-$(CONFIG_OCFS2_FS) += ocfs2.o ocfs2_stackglue.o ocfs2_stack_o2cb.o ocfs2-objs := \ alloc.o \ @@ -24,8 +24,6 @@ ocfs2-objs := \ namei.o \ resize.o \ slot_map.o \ - stackglue.o \ - stack_o2cb.o \ suballoc.o \ super.o \ symlink.o \ @@ -33,5 +31,8 @@ ocfs2-objs := \ uptodate.o \ ver.o +ocfs2_stackglue-objs := stackglue.o +ocfs2_stack_o2cb-objs := stack_o2cb.o + obj-$(CONFIG_OCFS2_FS) += cluster/ obj-$(CONFIG_OCFS2_FS) += dlm/ diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 8a9c84909b..f62a9e4fc3 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -2641,7 +2641,7 @@ int ocfs2_dlm_init(struct ocfs2_super *osb) mlog_errno(status); mlog(ML_ERROR, "could not find this host's node number\n"); - ocfs2_cluster_disconnect(conn); + ocfs2_cluster_disconnect(conn, 0); goto bail; } @@ -2663,7 +2663,8 @@ bail: return status; } -void ocfs2_dlm_shutdown(struct ocfs2_super *osb) +void ocfs2_dlm_shutdown(struct ocfs2_super *osb, + int hangup_pending) { mlog_entry_void(); @@ -2683,7 +2684,7 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb) ocfs2_lock_res_free(&osb->osb_super_lockres); ocfs2_lock_res_free(&osb->osb_rename_lockres); - ocfs2_cluster_disconnect(osb->cconn); + ocfs2_cluster_disconnect(osb->cconn, hangup_pending); osb->cconn = NULL; ocfs2_dlm_shutdown_debug(osb); diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h index 34b7598a0d..2bb01f09c1 100644 --- a/fs/ocfs2/dlmglue.h +++ b/fs/ocfs2/dlmglue.h @@ -58,7 +58,7 @@ struct ocfs2_meta_lvb { #define OCFS2_LOCK_NONBLOCK (0x04) int ocfs2_dlm_init(struct ocfs2_super *osb); -void ocfs2_dlm_shutdown(struct ocfs2_super *osb); +void ocfs2_dlm_shutdown(struct ocfs2_super *osb, int hangup_pending); void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res); void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, enum ocfs2_lock_type type, diff --git a/fs/ocfs2/stack_o2cb.c b/fs/ocfs2/stack_o2cb.c index c9bc3541a3..ac1d74c63b 100644 --- a/fs/ocfs2/stack_o2cb.c +++ b/fs/ocfs2/stack_o2cb.c @@ -18,7 +18,7 @@ */ #include -#include +#include /* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */ #include @@ -33,6 +33,8 @@ struct o2dlm_private { struct dlm_eviction_cb op_eviction_cb; }; +static struct ocfs2_stack_plugin o2cb_stack; + /* These should be identical */ #if (DLM_LOCK_IV != LKM_IVMODE) # error Lock modes do not match @@ -158,23 +160,23 @@ static int dlm_status_to_errno(enum dlm_status status) static void o2dlm_lock_ast_wrapper(void *astarg) { - BUG_ON(stack_glue_lproto == NULL); + BUG_ON(o2cb_stack.sp_proto == NULL); - stack_glue_lproto->lp_lock_ast(astarg); + o2cb_stack.sp_proto->lp_lock_ast(astarg); } static void o2dlm_blocking_ast_wrapper(void *astarg, int level) { - BUG_ON(stack_glue_lproto == NULL); + BUG_ON(o2cb_stack.sp_proto == NULL); - stack_glue_lproto->lp_blocking_ast(astarg, level); + o2cb_stack.sp_proto->lp_blocking_ast(astarg, level); } static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status) { int error = dlm_status_to_errno(status); - BUG_ON(stack_glue_lproto == NULL); + BUG_ON(o2cb_stack.sp_proto == NULL); /* * In o2dlm, you can get both the lock_ast() for the lock being @@ -190,7 +192,7 @@ static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status) if (status == DLM_CANCELGRANT) return; - stack_glue_lproto->lp_unlock_ast(astarg, error); + o2cb_stack.sp_proto->lp_unlock_ast(astarg, error); } static int o2cb_dlm_lock(struct ocfs2_cluster_connection *conn, @@ -267,6 +269,7 @@ static int o2cb_cluster_connect(struct ocfs2_cluster_connection *conn) struct dlm_protocol_version dlm_version; BUG_ON(conn == NULL); + BUG_ON(o2cb_stack.sp_proto == NULL); /* for now we only have one cluster/node, make sure we see it * in the heartbeat universe */ @@ -314,7 +317,8 @@ out: return rc; } -static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn) +static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn, + int hangup_pending) { struct dlm_ctxt *dlm = conn->cc_lockspace; struct o2dlm_private *priv = conn->cc_private; @@ -393,3 +397,24 @@ struct ocfs2_stack_operations o2cb_stack_ops = { .dump_lksb = o2cb_dump_lksb, }; +static struct ocfs2_stack_plugin o2cb_stack = { + .sp_name = "o2cb", + .sp_ops = &o2cb_stack_ops, + .sp_owner = THIS_MODULE, +}; + +static int __init o2cb_stack_init(void) +{ + return ocfs2_stack_glue_register(&o2cb_stack); +} + +static void __exit o2cb_stack_exit(void) +{ + ocfs2_stack_glue_unregister(&o2cb_stack); +} + +MODULE_AUTHOR("Oracle"); +MODULE_DESCRIPTION("ocfs2 driver for the classic o2cb stack"); +MODULE_LICENSE("GPL"); +module_init(o2cb_stack_init); +module_exit(o2cb_stack_exit); diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c index e197367b6b..1978c9cff0 100644 --- a/fs/ocfs2/stackglue.c +++ b/fs/ocfs2/stackglue.c @@ -18,17 +18,176 @@ * General Public License for more details. */ +#include +#include +#include #include #include -/* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */ -#include +#include "stackglue.h" -#include "cluster/masklog.h" +static struct ocfs2_locking_protocol *lproto; +static DEFINE_SPINLOCK(ocfs2_stack_lock); +static LIST_HEAD(ocfs2_stack_list); -#include "stackglue.h" +/* + * The stack currently in use. If not null, active_stack->sp_count > 0, + * the module is pinned, and the locking protocol cannot be changed. + */ +static struct ocfs2_stack_plugin *active_stack; + +static struct ocfs2_stack_plugin *ocfs2_stack_lookup(const char *name) +{ + struct ocfs2_stack_plugin *p; + + assert_spin_locked(&ocfs2_stack_lock); + + list_for_each_entry(p, &ocfs2_stack_list, sp_list) { + if (!strcmp(p->sp_name, name)) + return p; + } + + return NULL; +} + +static int ocfs2_stack_driver_request(const char *name) +{ + int rc; + struct ocfs2_stack_plugin *p; + + spin_lock(&ocfs2_stack_lock); + + if (active_stack) { + /* + * If the active stack isn't the one we want, it cannot + * be selected right now. + */ + if (!strcmp(active_stack->sp_name, name)) + rc = 0; + else + rc = -EBUSY; + goto out; + } + + p = ocfs2_stack_lookup(name); + if (!p || !try_module_get(p->sp_owner)) { + rc = -ENOENT; + goto out; + } + + /* Ok, the stack is pinned */ + p->sp_count++; + active_stack = p; + + rc = 0; + +out: + spin_unlock(&ocfs2_stack_lock); + return rc; +} + +/* + * This function looks up the appropriate stack and makes it active. If + * there is no stack, it tries to load it. It will fail if the stack still + * cannot be found. It will also fail if a different stack is in use. + */ +static int ocfs2_stack_driver_get(const char *name) +{ + int rc; + + rc = ocfs2_stack_driver_request(name); + if (rc == -ENOENT) { + request_module("ocfs2_stack_%s", name); + rc = ocfs2_stack_driver_request(name); + } + + if (rc == -ENOENT) { + printk(KERN_ERR + "ocfs2: Cluster stack driver \"%s\" cannot be found\n", + name); + } else if (rc == -EBUSY) { + printk(KERN_ERR + "ocfs2: A different cluster stack driver is in use\n"); + } + + return rc; +} -struct ocfs2_locking_protocol *stack_glue_lproto; +static void ocfs2_stack_driver_put(void) +{ + spin_lock(&ocfs2_stack_lock); + BUG_ON(active_stack == NULL); + BUG_ON(active_stack->sp_count == 0); + + active_stack->sp_count--; + if (!active_stack->sp_count) { + module_put(active_stack->sp_owner); + active_stack = NULL; + } + spin_unlock(&ocfs2_stack_lock); +} + +int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin) +{ + int rc; + + spin_lock(&ocfs2_stack_lock); + if (!ocfs2_stack_lookup(plugin->sp_name)) { + plugin->sp_count = 0; + plugin->sp_proto = lproto; + list_add(&plugin->sp_list, &ocfs2_stack_list); + printk(KERN_INFO "ocfs2: Registered cluster interface %s\n", + plugin->sp_name); + rc = 0; + } else { + printk(KERN_ERR "ocfs2: Stack \"%s\" already registered\n", + plugin->sp_name); + rc = -EEXIST; + } + spin_unlock(&ocfs2_stack_lock); + + return rc; +} +EXPORT_SYMBOL_GPL(ocfs2_stack_glue_register); + +void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin) +{ + struct ocfs2_stack_plugin *p; + + spin_lock(&ocfs2_stack_lock); + p = ocfs2_stack_lookup(plugin->sp_name); + if (p) { + BUG_ON(p != plugin); + BUG_ON(plugin == active_stack); + BUG_ON(plugin->sp_count != 0); + list_del_init(&plugin->sp_list); + printk(KERN_INFO "ocfs2: Unregistered cluster interface %s\n", + plugin->sp_name); + } else { + printk(KERN_ERR "Stack \"%s\" is not registered\n", + plugin->sp_name); + } + spin_unlock(&ocfs2_stack_lock); +} +EXPORT_SYMBOL_GPL(ocfs2_stack_glue_unregister); + +void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto) +{ + struct ocfs2_stack_plugin *p; + + BUG_ON(proto == NULL); + + spin_lock(&ocfs2_stack_lock); + BUG_ON(active_stack != NULL); + + lproto = proto; + list_for_each_entry(p, &ocfs2_stack_list, sp_list) { + p->sp_proto = lproto; + } + + spin_unlock(&ocfs2_stack_lock); +} +EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_locking_protocol); int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn, @@ -39,26 +198,29 @@ int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn, unsigned int namelen, void *astarg) { - BUG_ON(stack_glue_lproto == NULL); + BUG_ON(lproto == NULL); - return o2cb_stack_ops.dlm_lock(conn, mode, lksb, flags, - name, namelen, astarg); + return active_stack->sp_ops->dlm_lock(conn, mode, lksb, flags, + name, namelen, astarg); } +EXPORT_SYMBOL_GPL(ocfs2_dlm_lock); int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn, union ocfs2_dlm_lksb *lksb, u32 flags, void *astarg) { - BUG_ON(stack_glue_lproto == NULL); + BUG_ON(lproto == NULL); - return o2cb_stack_ops.dlm_unlock(conn, lksb, flags, astarg); + return active_stack->sp_ops->dlm_unlock(conn, lksb, flags, astarg); } +EXPORT_SYMBOL_GPL(ocfs2_dlm_unlock); int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb) { - return o2cb_stack_ops.lock_status(lksb); + return active_stack->sp_ops->lock_status(lksb); } +EXPORT_SYMBOL_GPL(ocfs2_dlm_lock_status); /* * Why don't we cast to ocfs2_meta_lvb? The "clean" answer is that we @@ -67,13 +229,15 @@ int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb) */ void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb) { - return o2cb_stack_ops.lock_lvb(lksb); + return active_stack->sp_ops->lock_lvb(lksb); } +EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb); void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb) { - o2cb_stack_ops.dump_lksb(lksb); + active_stack->sp_ops->dump_lksb(lksb); } +EXPORT_SYMBOL_GPL(ocfs2_dlm_dump_lksb); int ocfs2_cluster_connect(const char *group, int grouplen, @@ -107,11 +271,16 @@ int ocfs2_cluster_connect(const char *group, new_conn->cc_recovery_data = recovery_data; /* Start the new connection at our maximum compatibility level */ - new_conn->cc_version = stack_glue_lproto->lp_max_version; + new_conn->cc_version = lproto->lp_max_version; + + /* This will pin the stack driver if successful */ + rc = ocfs2_stack_driver_get("o2cb"); + if (rc) + goto out_free; - rc = o2cb_stack_ops.connect(new_conn); + rc = active_stack->sp_ops->connect(new_conn); if (rc) { - mlog_errno(rc); + ocfs2_stack_driver_put(); goto out_free; } @@ -124,39 +293,60 @@ out_free: out: return rc; } +EXPORT_SYMBOL_GPL(ocfs2_cluster_connect); -int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn) +/* If hangup_pending is 0, the stack driver will be dropped */ +int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn, + int hangup_pending) { int ret; BUG_ON(conn == NULL); - ret = o2cb_stack_ops.disconnect(conn); + ret = active_stack->sp_ops->disconnect(conn, hangup_pending); /* XXX Should we free it anyway? */ - if (!ret) + if (!ret) { kfree(conn); + if (!hangup_pending) + ocfs2_stack_driver_put(); + } return ret; } +EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect); void ocfs2_cluster_hangup(const char *group, int grouplen) { BUG_ON(group == NULL); BUG_ON(group[grouplen] != '\0'); - o2cb_stack_ops.hangup(group, grouplen); + active_stack->sp_ops->hangup(group, grouplen); + + /* cluster_disconnect() was called with hangup_pending==1 */ + ocfs2_stack_driver_put(); } +EXPORT_SYMBOL_GPL(ocfs2_cluster_hangup); int ocfs2_cluster_this_node(unsigned int *node) { - return o2cb_stack_ops.this_node(node); + return active_stack->sp_ops->this_node(node); } +EXPORT_SYMBOL_GPL(ocfs2_cluster_this_node); -void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto) + +static int __init ocfs2_stack_glue_init(void) { - BUG_ON(proto != NULL); + return 0; +} - stack_glue_lproto = proto; +static void __exit ocfs2_stack_glue_exit(void) +{ + lproto = NULL; } +MODULE_AUTHOR("Oracle"); +MODULE_DESCRIPTION("ocfs2 cluter stack glue layer"); +MODULE_LICENSE("GPL"); +module_init(ocfs2_stack_glue_init); +module_exit(ocfs2_stack_glue_exit); diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h index 083632215d..c96c8bb768 100644 --- a/fs/ocfs2/stackglue.h +++ b/fs/ocfs2/stackglue.h @@ -119,14 +119,21 @@ struct ocfs2_stack_operations { * Once ->disconnect() has returned, the connection structure will * be freed. Thus, a stack must not return from ->disconnect() * until it will no longer reference the conn pointer. + * + * If hangup_pending is zero, ocfs2_cluster_disconnect() will also + * be dropping the reference on the module. */ - int (*disconnect)(struct ocfs2_cluster_connection *conn); + int (*disconnect)(struct ocfs2_cluster_connection *conn, + int hangup_pending); /* * ocfs2_cluster_hangup() exists for compatibility with older * ocfs2 tools. Only the classic stack really needs it. As such * ->hangup() is not required of all stacks. See the comment by * ocfs2_cluster_hangup() for more details. + * + * Note that ocfs2_cluster_hangup() can only be called if + * hangup_pending was passed to ocfs2_cluster_disconnect(). */ void (*hangup)(const char *group, int grouplen); @@ -184,13 +191,32 @@ struct ocfs2_stack_operations { void (*dump_lksb)(union ocfs2_dlm_lksb *lksb); }; +/* + * Each stack plugin must describe itself by registering a + * ocfs2_stack_plugin structure. This is only seen by stackglue and the + * stack driver. + */ +struct ocfs2_stack_plugin { + char *sp_name; + struct ocfs2_stack_operations *sp_ops; + struct module *sp_owner; + + /* These are managed by the stackglue code. */ + struct list_head sp_list; + unsigned int sp_count; + struct ocfs2_locking_protocol *sp_proto; +}; + + +/* Used by the filesystem */ int ocfs2_cluster_connect(const char *group, int grouplen, void (*recovery_handler)(int node_num, void *recovery_data), void *recovery_data, struct ocfs2_cluster_connection **conn); -int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn); +int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn, + int hangup_pending); void ocfs2_cluster_hangup(const char *group, int grouplen); int ocfs2_cluster_this_node(unsigned int *node); @@ -212,6 +238,8 @@ void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb); void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto); -extern struct ocfs2_locking_protocol *stack_glue_lproto; -extern struct ocfs2_stack_operations o2cb_stack_ops; + +/* Used by stack plugins */ +int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin); +void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin); #endif /* STACKGLUE_H */ diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index b4a02a0066..e27a0d47ea 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -1186,7 +1186,7 @@ leave: static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err) { - int tmp; + int tmp, hangup_needed = 0; struct ocfs2_super *osb = NULL; char nodestr[8]; @@ -1225,19 +1225,21 @@ static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err) ocfs2_release_system_inodes(osb); - if (osb->cconn) - ocfs2_dlm_shutdown(osb); - - debugfs_remove(osb->osb_debug_root); - /* - * This is a small hack to move ocfs2_hb_ctl into stackglue. * If we're dismounting due to mount error, mount.ocfs2 will clean * up heartbeat. If we're a local mount, there is no heartbeat. * If we failed before we got a uuid_str yet, we can't stop * heartbeat. Otherwise, do it. */ if (!mnt_err && !ocfs2_mount_local(osb) && osb->uuid_str) + hangup_needed = 1; + + if (osb->cconn) + ocfs2_dlm_shutdown(osb, hangup_needed); + + debugfs_remove(osb->osb_debug_root); + + if (hangup_needed) ocfs2_cluster_hangup(osb->uuid_str, strlen(osb->uuid_str)); atomic_set(&osb->vol_state, VOLUME_DISMOUNTED);