5 files changed, 262 insertions, 63 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 12accb08fe02..9f203ef4da61 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -23,6 +23,8 @@
 #include <linux/module.h>
 #include <linux/rwsem.h>
 #include <asm/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
 
 #include "gfs2.h"
 #include "incore.h"
@@ -40,14 +42,22 @@ struct gfs2_gl_hash_bucket {
         struct hlist_head hb_list;
 };
 
+struct glock_iter {
+        int hash;                     /* hash bucket index         */
+        struct gfs2_sbd *sdp;         /* incore superblock         */
+        struct gfs2_glock *gl;        /* current glock struct      */
+        struct hlist_head *hb_list;   /* current hash bucket ptr   */
+        struct seq_file *seq;         /* sequence file for debugfs */
+        char string[512];             /* scratch space             */
+};
+
 typedef void (*glock_examiner) (struct gfs2_glock * gl);
 
 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
-static int dump_glock(struct gfs2_glock *gl);
-static int dump_inode(struct gfs2_inode *ip);
 static void gfs2_glock_xmote_th(struct gfs2_holder *gh);
 static void gfs2_glock_drop_th(struct gfs2_glock *gl);
 static DECLARE_RWSEM(gfs2_umount_flush_sem);
+static struct dentry *gfs2_root;
 
 #define GFS2_GL_HASH_SHIFT      15
 #define GFS2_GL_HASH_SIZE       (1 << GFS2_GL_HASH_SHIFT)
@@ -1109,6 +1119,20 @@ find_holder_by_owner(struct list_head *head, struct task_struct *owner)
         return NULL;
 }
 
+static void print_dbg(struct glock_iter *gi, const char *fmt, ...)
+{
+        va_list args;
+
+        va_start(args, fmt);
+        if (gi) {
+                vsprintf(gi->string, fmt, args);
+                seq_printf(gi->seq, gi->string);
+        }
+        else
+                vprintk(fmt, args);
+        va_end(args);
+}
+
 /**
  * add_to_queue - Add a holder to the wait queue (but look for recursion)
  * @gh: the holder structure to add
@@ -1849,31 +1873,32 @@ void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
  * Returns: 0 on success, -ENOBUFS when we run out of space
  */
 
-static int dump_holder(char *str, struct gfs2_holder *gh)
+static int dump_holder(struct glock_iter *gi, char *str,
+                       struct gfs2_holder *gh)
 {
         unsigned int x;
-        int error = -ENOBUFS;
 
-        printk(KERN_INFO "  %s\n", str);
-        printk(KERN_INFO "    owner = %ld\n",
+        print_dbg(gi, "  %s\n", str);
+        print_dbg(gi, "    owner = %ld\n",
                    (gh->gh_owner) ? (long)gh->gh_owner->pid : -1);
-        printk(KERN_INFO "    gh_state = %u\n", gh->gh_state);
-        printk(KERN_INFO "    gh_flags =");
+        print_dbg(gi, "    gh_state = %u\n", gh->gh_state);
+        print_dbg(gi, "    gh_flags =");
         for (x = 0; x < 32; x++)
                 if (gh->gh_flags & (1 << x))
-                        printk(" %u", x);
-        printk(" \n");
-        printk(KERN_INFO "    error = %d\n", gh->gh_error);
-        printk(KERN_INFO "    gh_iflags =");
+                        print_dbg(gi, " %u", x);
+        print_dbg(gi, " \n");
+        print_dbg(gi, "    error = %d\n", gh->gh_error);
+        print_dbg(gi, "    gh_iflags =");
         for (x = 0; x < 32; x++)
                 if (test_bit(x, &gh->gh_iflags))
-                        printk(" %u", x);
-        printk(" \n");
-        print_symbol(KERN_INFO "    initialized at: %s\n", gh->gh_ip);
-
-        error = 0;
+                        print_dbg(gi, " %u", x);
+        print_dbg(gi, " \n");
+        if (gi)
+                print_dbg(gi, "    initialized at: 0x%x\n", gh->gh_ip);
+        else
+                print_symbol(KERN_INFO "    initialized at: %s\n", gh->gh_ip);
 
-        return error;
+        return 0;
 }
 
 /**
@@ -1883,25 +1908,20 @@ static int dump_holder(char *str, struct gfs2_holder *gh)
  * Returns: 0 on success, -ENOBUFS when we run out of space
  */
 
-static int dump_inode(struct gfs2_inode *ip)
+static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip)
 {
         unsigned int x;
-        int error = -ENOBUFS;
 
-        printk(KERN_INFO "  Inode:\n");
-        printk(KERN_INFO "    num = %llu %llu\n",
-                    (unsigned long long)ip->i_num.no_formal_ino,
-                    (unsigned long long)ip->i_num.no_addr);
-        printk(KERN_INFO "    type = %u\n", IF2DT(ip->i_inode.i_mode));
-        printk(KERN_INFO "    i_flags =");
+        print_dbg(gi, "  Inode:\n");
+        print_dbg(gi, "    num = %llu/%llu\n",
+                    ip->i_num.no_formal_ino, ip->i_num.no_addr);
+        print_dbg(gi, "    type = %u\n", IF2DT(ip->i_inode.i_mode));
+        print_dbg(gi, "    i_flags =");
         for (x = 0; x < 32; x++)
                 if (test_bit(x, &ip->i_flags))
-                        printk(" %u", x);
-        printk(" \n");
-
-        error = 0;
-
-        return error;
+                        print_dbg(gi, " %u", x);
+        print_dbg(gi, " \n");
+        return 0;
 }
 
 /**
@@ -1912,7 +1932,7 @@ static int dump_inode(struct gfs2_inode *ip)
  * Returns: 0 on success, -ENOBUFS when we run out of space
  */
 
-static int dump_glock(struct gfs2_glock *gl)
+static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl)
 {
         struct gfs2_holder *gh;
         unsigned int x;
@@ -1920,66 +1940,66 @@ static int dump_glock(struct gfs2_glock *gl)
 
         spin_lock(&gl->gl_spin);
 
-        printk(KERN_INFO "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type,
-               (unsigned long long)gl->gl_name.ln_number);
-        printk(KERN_INFO "  gl_flags =");
+        print_dbg(gi, "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type,
+                   (unsigned long long)gl->gl_name.ln_number);
+        print_dbg(gi, "  gl_flags =");
         for (x = 0; x < 32; x++) {
                 if (test_bit(x, &gl->gl_flags))
-                        printk(" %u", x);
-        }
-        printk(" \n");
-        printk(KERN_INFO "  gl_ref = %d\n", atomic_read(&gl->gl_ref));
-        printk(KERN_INFO "  gl_state = %u\n", gl->gl_state);
-        printk(KERN_INFO "  gl_owner = %s\n", gl->gl_owner->comm);
-        print_symbol(KERN_INFO "  gl_ip = %s\n", gl->gl_ip);
-        printk(KERN_INFO "  req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no");
-        printk(KERN_INFO "  req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no");
-        printk(KERN_INFO "  lvb_count = %d\n", atomic_read(&gl->gl_lvb_count));
-        printk(KERN_INFO "  object = %s\n", (gl->gl_object) ? "yes" : "no");
-        printk(KERN_INFO "  le = %s\n",
+                        print_dbg(gi, " %u", x);
+        }
+        print_dbg(gi, " \n");
+        print_dbg(gi, "  gl_ref = %d\n", atomic_read(&gl->gl_ref));
+        print_dbg(gi, "  gl_state = %u\n", gl->gl_state);
+        print_dbg(gi, "  gl_owner = %s\n", gl->gl_owner->comm);
+        print_dbg(gi, "  gl_ip = %lu\n", gl->gl_ip);
+        print_dbg(gi, "  req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no");
+        print_dbg(gi, "  req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no");
+        print_dbg(gi, "  lvb_count = %d\n", atomic_read(&gl->gl_lvb_count));
+        print_dbg(gi, "  object = %s\n", (gl->gl_object) ? "yes" : "no");
+        print_dbg(gi, "  le = %s\n",
                    (list_empty(&gl->gl_le.le_list)) ? "no" : "yes");
-        printk(KERN_INFO "  reclaim = %s\n",
-                    (list_empty(&gl->gl_reclaim)) ? "no" : "yes");
+        print_dbg(gi, "  reclaim = %s\n",
+                   (list_empty(&gl->gl_reclaim)) ? "no" : "yes");
         if (gl->gl_aspace)
-                printk(KERN_INFO "  aspace = 0x%p nrpages = %lu\n", gl->gl_aspace,
-                       gl->gl_aspace->i_mapping->nrpages);
+                print_dbg(gi, "  aspace = 0x%p nrpages = %lu\n", gl->gl_aspace,
+                           gl->gl_aspace->i_mapping->nrpages);
         else
-                printk(KERN_INFO "  aspace = no\n");
-        printk(KERN_INFO "  ail = %d\n", atomic_read(&gl->gl_ail_count));
+                print_dbg(gi, "  aspace = no\n");
+        print_dbg(gi, "  ail = %d\n", atomic_read(&gl->gl_ail_count));
         if (gl->gl_req_gh) {
-                error = dump_holder("Request", gl->gl_req_gh);
+                error = dump_holder(gi, "Request", gl->gl_req_gh);
                 if (error)
                         goto out;
         }
         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
-                error = dump_holder("Holder", gh);
+                error = dump_holder(gi, "Holder", gh);
                 if (error)
                         goto out;
         }
         list_for_each_entry(gh, &gl->gl_waiters1, gh_list) {
-                error = dump_holder("Waiter1", gh);
+                error = dump_holder(gi, "Waiter1", gh);
                 if (error)
                         goto out;
         }
         list_for_each_entry(gh, &gl->gl_waiters2, gh_list) {
-                error = dump_holder("Waiter2", gh);
+                error = dump_holder(gi, "Waiter2", gh);
                 if (error)
                         goto out;
         }
         list_for_each_entry(gh, &gl->gl_waiters3, gh_list) {
-                error = dump_holder("Waiter3", gh);
+                error = dump_holder(gi, "Waiter3", gh);
                 if (error)
                         goto out;
         }
         if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) {
                 if (!test_bit(GLF_LOCK, &gl->gl_flags) &&
-                    list_empty(&gl->gl_holders)) {
-                        error = dump_inode(gl->gl_object);
+                        list_empty(&gl->gl_holders)) {
+                        error = dump_inode(gi, gl->gl_object);
                         if (error)
                                 goto out;
                 } else {
                         error = -ENOBUFS;
-                        printk(KERN_INFO "  Inode: busy\n");
+                        print_dbg(gi, "  Inode: busy\n");
                 }
         }
 
@@ -2014,7 +2034,7 @@ static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
                         if (gl->gl_sbd != sdp)
                                 continue;
 
-                        error = dump_glock(gl);
+                        error = dump_glock(NULL, gl);
                         if (error)
                                 break;
                 }
@@ -2043,3 +2063,171 @@ int __init gfs2_glock_init(void)
         return 0;
 }
 
+static int gfs2_glock_iter_next(struct glock_iter *gi)
+{
+        while (1) {
+                if (!gi->hb_list) {  /* If we don't have a hash bucket yet */
+                        gi->hb_list = &gl_hash_table[gi->hash].hb_list;
+                        if (hlist_empty(gi->hb_list)) {
+                                gi->hash++;
+                                gi->hb_list = NULL;
+                                if (gi->hash >= GFS2_GL_HASH_SIZE)
+                                        return 1;
+                                else
+                                        continue;
+                        }
+                        if (!hlist_empty(gi->hb_list)) {
+                                gi->gl = list_entry(gi->hb_list->first,
+                                                    struct gfs2_glock,
+                                                    gl_list);
+                        }
+                } else {
+                        if (gi->gl->gl_list.next == NULL) {
+                                gi->hash++;
+                                gi->hb_list = NULL;
+                                continue;
+                        }
+                        gi->gl = list_entry(gi->gl->gl_list.next,
+                                            struct gfs2_glock, gl_list);
+                }
+                if (gi->gl)
+                        break;
+        }
+        return 0;
+}
+
+static void gfs2_glock_iter_free(struct glock_iter *gi)
+{
+        kfree(gi);
+}
+
+static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp)
+{
+        struct glock_iter *gi;
+
+        gi = kmalloc(sizeof (*gi), GFP_KERNEL);
+        if (!gi)
+                return NULL;
+
+        gi->sdp = sdp;
+        gi->hash = 0;
+        gi->gl = NULL;
+        gi->hb_list = NULL;
+        gi->seq = NULL;
+        memset(gi->string, 0, sizeof(gi->string));
+
+        if (gfs2_glock_iter_next(gi)) {
+                gfs2_glock_iter_free(gi);
+                return NULL;
+        }
+
+        return gi;
+}
+
+static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos)
+{
+        struct glock_iter *gi;
+        loff_t n = *pos;
+
+        gi = gfs2_glock_iter_init(file->private);
+        if (!gi)
+                return NULL;
+
+        while (n--) {
+                if (gfs2_glock_iter_next(gi)) {
+                        gfs2_glock_iter_free(gi);
+                        return NULL;
+                }
+        }
+
+        return gi;
+}
+
+static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr,
+                                 loff_t *pos)
+{
+        struct glock_iter *gi = iter_ptr;
+
+        (*pos)++;
+
+        if (gfs2_glock_iter_next(gi)) {
+                gfs2_glock_iter_free(gi);
+                return NULL;
+        }
+
+        return gi;
+}
+
+static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr)
+{
+        /* nothing for now */
+}
+
+static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
+{
+        struct glock_iter *gi = iter_ptr;
+
+        gi->seq = file;
+        dump_glock(gi, gi->gl);
+
+        return 0;
+}
+
+static struct seq_operations gfs2_glock_seq_ops = {
+        .start = gfs2_glock_seq_start,
+        .next  = gfs2_glock_seq_next,
+        .stop  = gfs2_glock_seq_stop,
+        .show  = gfs2_glock_seq_show,
+};
+
+static int gfs2_debugfs_open(struct inode *inode, struct file *file)
+{
+        struct seq_file *seq;
+        int ret;
+
+        ret = seq_open(file, &gfs2_glock_seq_ops);
+        if (ret)
+                return ret;
+
+        seq = file->private_data;
+        seq->private = inode->i_private;
+
+        return 0;
+}
+
+static const struct file_operations gfs2_debug_fops = {
+        .owner   = THIS_MODULE,
+        .open    = gfs2_debugfs_open,
+        .read    = seq_read,
+        .llseek  = seq_lseek,
+        .release = seq_release
+};
+
+int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
+{
+        sdp->debugfs_dentry = debugfs_create_file(sdp->sd_table_name,
+                                                  S_IFREG | S_IRUGO,
+                                                  gfs2_root, sdp,
+                                                  &gfs2_debug_fops);
+        if (!sdp->debugfs_dentry)
+                return -ENOMEM;
+
+        return 0;
+}
+
+void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
+{
+        if (sdp->debugfs_dentry)
+                debugfs_remove(sdp->debugfs_dentry);
+}
+
+int gfs2_register_debugfs(void)
+{
+        gfs2_root = debugfs_create_dir("gfs2", NULL);
+        return gfs2_root ? 0 : -ENOMEM;
+}
+
+void gfs2_unregister_debugfs(void)
+{
+        debugfs_remove(gfs2_root);
+}
diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h
index f50e40ceca43..d7cef7408728 100644
--- a/fs/gfs2/glock.h
+++ b/fs/gfs2/glock.h
@@ -135,5 +135,9 @@ void gfs2_scand_internal(struct gfs2_sbd *sdp);
 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
 
 int __init gfs2_glock_init(void);
+int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
+void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
+int gfs2_register_debugfs(void);
+void gfs2_unregister_debugfs(void);
 
 #endif /* __GLOCK_DOT_H__ */
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 49f0dbf40d86..7555261d911f 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -611,6 +611,7 @@ struct gfs2_sbd {
 
         unsigned long sd_last_warning;
         struct vfsmount *sd_gfs2mnt;
+        struct dentry *debugfs_dentry; /* for debugfs */
 };
 
 #endif /* __INCORE_DOT_H__ */
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index 6e8a59809abf..218395371dbe 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -103,6 +103,8 @@ static int __init init_gfs2_fs(void)
         if (error)
                 goto fail_unregister;
 
+        gfs2_register_debugfs();
+
         printk("GFS2 (built %s %s) installed\n", __DATE__, __TIME__);
 
         return 0;
@@ -130,6 +132,7 @@ fail:
 
 static void __exit exit_gfs2_fs(void)
 {
+        gfs2_unregister_debugfs();
         unregister_filesystem(&gfs2_fs_type);
         unregister_filesystem(&gfs2meta_fs_type);
 
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index ee54cb667083..ecb8b18de0ee 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -690,6 +690,8 @@ static int fill_super(struct super_block *sb, void *data, int silent)
         if (error)
                 goto fail;
 
+        gfs2_create_debugfs_file(sdp);
+
         error = gfs2_sys_fs_add(sdp);
         if (error)
                 goto fail;
@@ -896,6 +898,7 @@ error:
 
 static void gfs2_kill_sb(struct super_block *sb)
 {
+        gfs2_delete_debugfs_file(sb->s_fs_info);
         kill_block_super(sb);
 }