[git patches] Ocfs2 fixes

From: Mark Fasheh
Date: Mon Jun 16 2008 - 16:13:03 EST


This reverts a portion of the 'user-stack' unmount behavior back to how we
have traditionally handled unmount notification - via usermode callout to a
small helper application. Well, 'revert' is probably the wrong term. The
user-stack code explicitly never called the helper because we incorrectly
thought that an umount.ocfs2 might be able to do the work of tracking
final-unmount. As it turns out, that's not really possible (bind-mounts in
particular made this difficult) so we're going to go with the tried-and-true
umount handling for all Ocfs2 cluster stacks.


Please pull from 'upstream-linus' branch of
git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2.git upstream-linus

to receive the following updates:

fs/ocfs2/cluster/nodemanager.c | 74 +------------------------
fs/ocfs2/cluster/nodemanager.h | 4 -
fs/ocfs2/stack_o2cb.c | 41 +-------------
fs/ocfs2/stack_user.c | 3 +-
fs/ocfs2/stackglue.c | 119 +++++++++++++++++++++++++++++++++++++++-
fs/ocfs2/stackglue.h | 19 +-----
6 files changed, 123 insertions(+), 137 deletions(-)

Joel Becker (3):
ocfs2: Move the hb_ctl_path sysctl into the stack glue.
ocfs2: Move the call of ocfs2_hb_ctl into the stack glue.
ocfs2: Remove ->hangup() from stack glue operations.

diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index cf9401e..cfdb08b 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -21,7 +21,6 @@

#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/sysctl.h>
#include <linux/configfs.h>

#include "tcp.h"
@@ -36,65 +35,6 @@
* cluster references throughout where nodes are looked up */
struct o2nm_cluster *o2nm_single_cluster = NULL;

-#define OCFS2_MAX_HB_CTL_PATH 256
-static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl";
-
-static ctl_table ocfs2_nm_table[] = {
- {
- .ctl_name = 1,
- .procname = "hb_ctl_path",
- .data = ocfs2_hb_ctl_path,
- .maxlen = OCFS2_MAX_HB_CTL_PATH,
- .mode = 0644,
- .proc_handler = &proc_dostring,
- .strategy = &sysctl_string,
- },
- { .ctl_name = 0 }
-};
-
-static ctl_table ocfs2_mod_table[] = {
- {
- .ctl_name = FS_OCFS2_NM,
- .procname = "nm",
- .data = NULL,
- .maxlen = 0,
- .mode = 0555,
- .child = ocfs2_nm_table
- },
- { .ctl_name = 0}
-};
-
-static ctl_table ocfs2_kern_table[] = {
- {
- .ctl_name = FS_OCFS2,
- .procname = "ocfs2",
- .data = NULL,
- .maxlen = 0,
- .mode = 0555,
- .child = ocfs2_mod_table
- },
- { .ctl_name = 0}
-};
-
-static ctl_table ocfs2_root_table[] = {
- {
- .ctl_name = CTL_FS,
- .procname = "fs",
- .data = NULL,
- .maxlen = 0,
- .mode = 0555,
- .child = ocfs2_kern_table
- },
- { .ctl_name = 0 }
-};
-
-static struct ctl_table_header *ocfs2_table_header = NULL;
-
-const char *o2nm_get_hb_ctl_path(void)
-{
- return ocfs2_hb_ctl_path;
-}
-EXPORT_SYMBOL_GPL(o2nm_get_hb_ctl_path);

struct o2nm_node *o2nm_get_node_by_num(u8 node_num)
{
@@ -941,9 +881,6 @@ void o2nm_undepend_this_node(void)

static void __exit exit_o2nm(void)
{
- if (ocfs2_table_header)
- unregister_sysctl_table(ocfs2_table_header);
-
/* XXX sync with hb callbacks and shut down hb? */
o2net_unregister_hb_callbacks();
configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
@@ -964,16 +901,9 @@ static int __init init_o2nm(void)
if (ret)
goto out;

- ocfs2_table_header = register_sysctl_table(ocfs2_root_table);
- if (!ocfs2_table_header) {
- printk(KERN_ERR "nodemanager: unable to register sysctl\n");
- ret = -ENOMEM; /* or something. */
- goto out_o2net;
- }
-
ret = o2net_register_hb_callbacks();
if (ret)
- goto out_sysctl;
+ goto out_o2net;

config_group_init(&o2nm_cluster_group.cs_subsys.su_group);
mutex_init(&o2nm_cluster_group.cs_subsys.su_mutex);
@@ -990,8 +920,6 @@ static int __init init_o2nm(void)
configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
out_callbacks:
o2net_unregister_hb_callbacks();
-out_sysctl:
- unregister_sysctl_table(ocfs2_table_header);
out_o2net:
o2net_exit();
out:
diff --git a/fs/ocfs2/cluster/nodemanager.h b/fs/ocfs2/cluster/nodemanager.h
index 7c86036..c992ea0 100644
--- a/fs/ocfs2/cluster/nodemanager.h
+++ b/fs/ocfs2/cluster/nodemanager.h
@@ -33,10 +33,6 @@
#include <linux/configfs.h>
#include <linux/rbtree.h>

-#define FS_OCFS2_NM 1
-
-const char *o2nm_get_hb_ctl_path(void);
-
struct o2nm_node {
spinlock_t nd_lock;
struct config_item nd_item;
diff --git a/fs/ocfs2/stack_o2cb.c b/fs/ocfs2/stack_o2cb.c
index bbd1667..fcd120f 100644
--- a/fs/ocfs2/stack_o2cb.c
+++ b/fs/ocfs2/stack_o2cb.c
@@ -317,8 +317,7 @@ out:
return rc;
}

-static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn,
- int hangup_pending)
+static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn)
{
struct dlm_ctxt *dlm = conn->cc_lockspace;
struct o2dlm_private *priv = conn->cc_private;
@@ -333,43 +332,6 @@ static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn,
return 0;
}

-static void o2hb_stop(const char *group)
-{
- int ret;
- char *argv[5], *envp[3];
-
- argv[0] = (char *)o2nm_get_hb_ctl_path();
- argv[1] = "-K";
- argv[2] = "-u";
- argv[3] = (char *)group;
- argv[4] = NULL;
-
- mlog(0, "Run: %s %s %s %s\n", argv[0], argv[1], argv[2], argv[3]);
-
- /* minimal command environment taken from cpu_run_sbin_hotplug */
- envp[0] = "HOME=/";
- envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
- envp[2] = NULL;
-
- ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
- if (ret < 0)
- mlog_errno(ret);
-}
-
-/*
- * Hangup is a hack for tools compatibility. Older ocfs2-tools software
- * expects the filesystem to call "ocfs2_hb_ctl" during unmount. This
- * happens regardless of whether the DLM got started, so we can't do it
- * in ocfs2_cluster_disconnect(). We bring the o2hb_stop() function into
- * the glue and provide a "hangup" API for super.c to call.
- *
- * Other stacks will eventually provide a NULL ->hangup() pointer.
- */
-static void o2cb_cluster_hangup(const char *group, int grouplen)
-{
- o2hb_stop(group);
-}
-
static int o2cb_cluster_this_node(unsigned int *node)
{
int node_num;
@@ -388,7 +350,6 @@ static int o2cb_cluster_this_node(unsigned int *node)
static struct ocfs2_stack_operations o2cb_stack_ops = {
.connect = o2cb_cluster_connect,
.disconnect = o2cb_cluster_disconnect,
- .hangup = o2cb_cluster_hangup,
.this_node = o2cb_cluster_this_node,
.dlm_lock = o2cb_dlm_lock,
.dlm_unlock = o2cb_dlm_unlock,
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index 6b97d11..c021280 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -816,8 +816,7 @@ out:
return rc;
}

-static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn,
- int hangup_pending)
+static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
{
dlm_release_lockspace(conn->cc_lockspace, 2);
conn->cc_lockspace = NULL;
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
index 119f60c..10e149a 100644
--- a/fs/ocfs2/stackglue.c
+++ b/fs/ocfs2/stackglue.c
@@ -26,6 +26,7 @@
#include <linux/fs.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
+#include <linux/sysctl.h>

#include "ocfs2_fs.h"

@@ -33,11 +34,13 @@

#define OCFS2_STACK_PLUGIN_O2CB "o2cb"
#define OCFS2_STACK_PLUGIN_USER "user"
+#define OCFS2_MAX_HB_CTL_PATH 256

static struct ocfs2_locking_protocol *lproto;
static DEFINE_SPINLOCK(ocfs2_stack_lock);
static LIST_HEAD(ocfs2_stack_list);
static char cluster_stack_name[OCFS2_STACK_LABEL_LEN + 1];
+static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl";

/*
* The stack currently in use. If not null, active_stack->sp_count > 0,
@@ -349,7 +352,7 @@ int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,

BUG_ON(conn == NULL);

- ret = active_stack->sp_ops->disconnect(conn, hangup_pending);
+ ret = active_stack->sp_ops->disconnect(conn);

/* XXX Should we free it anyway? */
if (!ret) {
@@ -362,13 +365,48 @@ int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
}
EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect);

+/*
+ * Leave the group for this filesystem. This is executed by a userspace
+ * program (stored in ocfs2_hb_ctl_path).
+ */
+static void ocfs2_leave_group(const char *group)
+{
+ int ret;
+ char *argv[5], *envp[3];
+
+ argv[0] = ocfs2_hb_ctl_path;
+ argv[1] = "-K";
+ argv[2] = "-u";
+ argv[3] = (char *)group;
+ argv[4] = NULL;
+
+ /* minimal command environment taken from cpu_run_sbin_hotplug */
+ envp[0] = "HOME=/";
+ envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+ envp[2] = NULL;
+
+ ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ if (ret < 0) {
+ printk(KERN_ERR
+ "ocfs2: Error %d running user helper "
+ "\"%s %s %s %s\"\n",
+ ret, argv[0], argv[1], argv[2], argv[3]);
+ }
+}
+
+/*
+ * Hangup is a required post-umount. ocfs2-tools software expects the
+ * filesystem to call "ocfs2_hb_ctl" during unmount. This happens
+ * regardless of whether the DLM got started, so we can't do it
+ * in ocfs2_cluster_disconnect(). The ocfs2_leave_group() function does
+ * the actual work.
+ */
void ocfs2_cluster_hangup(const char *group, int grouplen)
{
BUG_ON(group == NULL);
BUG_ON(group[grouplen] != '\0');

- if (active_stack->sp_ops->hangup)
- active_stack->sp_ops->hangup(group, grouplen);
+ ocfs2_leave_group(group);

/* cluster_disconnect() was called with hangup_pending==1 */
ocfs2_stack_driver_put();
@@ -548,10 +586,83 @@ error:
return ret;
}

+/*
+ * Sysctl bits
+ *
+ * The sysctl lives at /proc/sys/fs/ocfs2/nm/hb_ctl_path. The 'nm' doesn't
+ * make as much sense in a multiple cluster stack world, but it's safer
+ * and easier to preserve the name.
+ */
+
+#define FS_OCFS2_NM 1
+
+static ctl_table ocfs2_nm_table[] = {
+ {
+ .ctl_name = 1,
+ .procname = "hb_ctl_path",
+ .data = ocfs2_hb_ctl_path,
+ .maxlen = OCFS2_MAX_HB_CTL_PATH,
+ .mode = 0644,
+ .proc_handler = &proc_dostring,
+ .strategy = &sysctl_string,
+ },
+ { .ctl_name = 0 }
+};
+
+static ctl_table ocfs2_mod_table[] = {
+ {
+ .ctl_name = FS_OCFS2_NM,
+ .procname = "nm",
+ .data = NULL,
+ .maxlen = 0,
+ .mode = 0555,
+ .child = ocfs2_nm_table
+ },
+ { .ctl_name = 0}
+};
+
+static ctl_table ocfs2_kern_table[] = {
+ {
+ .ctl_name = FS_OCFS2,
+ .procname = "ocfs2",
+ .data = NULL,
+ .maxlen = 0,
+ .mode = 0555,
+ .child = ocfs2_mod_table
+ },
+ { .ctl_name = 0}
+};
+
+static ctl_table ocfs2_root_table[] = {
+ {
+ .ctl_name = CTL_FS,
+ .procname = "fs",
+ .data = NULL,
+ .maxlen = 0,
+ .mode = 0555,
+ .child = ocfs2_kern_table
+ },
+ { .ctl_name = 0 }
+};
+
+static struct ctl_table_header *ocfs2_table_header = NULL;
+
+
+/*
+ * Initialization
+ */
+
static int __init ocfs2_stack_glue_init(void)
{
strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB);

+ ocfs2_table_header = register_sysctl_table(ocfs2_root_table);
+ if (!ocfs2_table_header) {
+ printk(KERN_ERR
+ "ocfs2 stack glue: unable to register sysctl\n");
+ return -ENOMEM; /* or something. */
+ }
+
return ocfs2_sysfs_init();
}

@@ -559,6 +670,8 @@ static void __exit ocfs2_stack_glue_exit(void)
{
lproto = NULL;
ocfs2_sysfs_exit();
+ if (ocfs2_table_header)
+ unregister_sysctl_table(ocfs2_table_header);
}

MODULE_AUTHOR("Oracle");
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index 005e4f1..db56281 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -134,22 +134,10 @@ struct ocfs2_stack_operations {
* 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.
+ * Once this call returns, the stack glue will be dropping this
+ * connection's reference on the module.
*/
- 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);
+ int (*disconnect)(struct ocfs2_cluster_connection *conn);

/*
* ->this_node() returns the cluster's unique identifier for the
@@ -258,4 +246,5 @@ void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto)
/* 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 */
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