ocfs2: add locking filter debugfs file

Add locking filter debugfs file, which is used to filter lock resources
dump from locking_state debugfs file.  We use d_filter_secs field to
filter lock resources dump, the default d_filter_secs(0) value filters
nothing, otherwise, only dump the last N seconds active lock resources.
This enhancement can avoid dumping lots of old records.  The
d_filter_secs value can be changed via locking_filter file.

[akpm@linux-foundation.org: fix undefined reference to `__udivdi3']
Link: http://lkml.kernel.org/r/20190611015414.27754-2-ghe@suse.com
Signed-off-by: Gang He <ghe@suse.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>	[build-tested]
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 5f696be267e7420cf4db482dfb2899a04be4997e..4089daba4c6fd7afb71af578d6b37c00768f1ffe 100644 (file)
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -2991,6 +2991,8 @@ struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
        kref_init(&dlm_debug->d_refcnt);
        INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
        dlm_debug->d_locking_state = NULL;
+       dlm_debug->d_locking_filter = NULL;
+       dlm_debug->d_filter_secs = 0;
 out:
        return dlm_debug;
 }
@@ -3090,10 +3092,34 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
        int i;
        char *lvb;
        struct ocfs2_lock_res *lockres = v;
+#ifdef CONFIG_OCFS2_FS_STATS
+       u64 now, last;
+       struct ocfs2_dlm_debug *dlm_debug =
+                       ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug;
+#endif
 
        if (!lockres)
                return -EINVAL;
 
+#ifdef CONFIG_OCFS2_FS_STATS
+       if (dlm_debug->d_filter_secs) {
+               now = ktime_to_us(ktime_get_real());
+               if (lockres->l_lock_prmode.ls_last >
+                   lockres->l_lock_exmode.ls_last)
+                       last = lockres->l_lock_prmode.ls_last;
+               else
+                       last = lockres->l_lock_exmode.ls_last;
+               /*
+                * Use d_filter_secs field to filter lock resources dump,
+                * the default d_filter_secs(0) value filters nothing,
+                * otherwise, only dump the last N seconds active lock
+                * resources.
+                */
+               if (div_u64(now - last, 1000000) > dlm_debug->d_filter_secs)
+                       return 0;
+       }
+#endif
+
        seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
 
        if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
@@ -3243,6 +3269,17 @@ static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
                goto out;
        }
 
+       dlm_debug->d_locking_filter = debugfs_create_u32("locking_filter",
+                                               0600,
+                                               osb->osb_debug_root,
+                                               &dlm_debug->d_filter_secs);
+       if (!dlm_debug->d_locking_filter) {
+               ret = -EINVAL;
+               mlog(ML_ERROR,
+                    "Unable to create locking filter debugfs file.\n");
+               goto out;
+       }
+
        ocfs2_get_dlm_debug(dlm_debug);
 out:
        return ret;
@@ -3254,6 +3291,7 @@ static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
 
        if (dlm_debug) {
                debugfs_remove(dlm_debug->d_locking_state);
+               debugfs_remove(dlm_debug->d_locking_filter);
                ocfs2_put_dlm_debug(dlm_debug);
        }
 }

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 5c111eabaa1d0b5fe8b46745c8c48fa657c9fa3d..c7539601555b94bbda097b40bfc12a3364ee5383 100644 (file)
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -223,6 +223,8 @@ struct ocfs2_orphan_scan {
 struct ocfs2_dlm_debug {
        struct kref d_refcnt;
        struct dentry *d_locking_state;
+       struct dentry *d_locking_filter;
+       u32 d_filter_secs;
        struct list_head d_lockres_tracking;
 };