3 files changed, 62 insertions, 80 deletions

diff --git a/fs/locks.c b/fs/locks.c
index c17bc00b1e8d..7f9a3ea47418 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2066,134 +2066,114 @@ int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
 
 EXPORT_SYMBOL_GPL(vfs_cancel_lock);
 
-static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx)
+#ifdef CONFIG_PROC_FS
+#include <linux/seq_file.h>
+
+static void lock_get_status(struct seq_file *f, struct file_lock *fl,
+                                                        int id, char *pfx)
 {
         struct inode *inode = NULL;
 
         if (fl->fl_file != NULL)
                 inode = fl->fl_file->f_path.dentry->d_inode;
 
-        out += sprintf(out, "%d:%s ", id, pfx);
+        seq_printf(f, "%d:%s ", id, pfx);
         if (IS_POSIX(fl)) {
-                out += sprintf(out, "%6s %s ",
+                seq_printf(f, "%6s %s ",
                              (fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ",
                              (inode == NULL) ? "*NOINODE*" :
                              mandatory_lock(inode) ? "MANDATORY" : "ADVISORY ");
         } else if (IS_FLOCK(fl)) {
                 if (fl->fl_type & LOCK_MAND) {
-                        out += sprintf(out, "FLOCK  MSNFS     ");
+                        seq_printf(f, "FLOCK  MSNFS     ");
                 } else {
-                        out += sprintf(out, "FLOCK  ADVISORY  ");
+                        seq_printf(f, "FLOCK  ADVISORY  ");
                 }
         } else if (IS_LEASE(fl)) {
-                out += sprintf(out, "LEASE  ");
+                seq_printf(f, "LEASE  ");
                 if (fl->fl_type & F_INPROGRESS)
-                        out += sprintf(out, "BREAKING  ");
+                        seq_printf(f, "BREAKING  ");
                 else if (fl->fl_file)
-                        out += sprintf(out, "ACTIVE    ");
+                        seq_printf(f, "ACTIVE    ");
                 else
-                        out += sprintf(out, "BREAKER   ");
+                        seq_printf(f, "BREAKER   ");
         } else {
-                out += sprintf(out, "UNKNOWN UNKNOWN  ");
+                seq_printf(f, "UNKNOWN UNKNOWN  ");
         }
         if (fl->fl_type & LOCK_MAND) {
-                out += sprintf(out, "%s ",
+                seq_printf(f, "%s ",
                                (fl->fl_type & LOCK_READ)
                                ? (fl->fl_type & LOCK_WRITE) ? "RW   " : "READ "
                                : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE ");
         } else {
-                out += sprintf(out, "%s ",
+                seq_printf(f, "%s ",
                                (fl->fl_type & F_INPROGRESS)
                                ? (fl->fl_type & F_UNLCK) ? "UNLCK" : "READ "
                                : (fl->fl_type & F_WRLCK) ? "WRITE" : "READ ");
         }
         if (inode) {
 #ifdef WE_CAN_BREAK_LSLK_NOW
-                out += sprintf(out, "%d %s:%ld ", fl->fl_pid,
+                seq_printf(f, "%d %s:%ld ", fl->fl_pid,
                                 inode->i_sb->s_id, inode->i_ino);
 #else
                 /* userspace relies on this representation of dev_t ;-( */
-                out += sprintf(out, "%d %02x:%02x:%ld ", fl->fl_pid,
+                seq_printf(f, "%d %02x:%02x:%ld ", fl->fl_pid,
                                 MAJOR(inode->i_sb->s_dev),
                                 MINOR(inode->i_sb->s_dev), inode->i_ino);
 #endif
         } else {
-                out += sprintf(out, "%d <none>:0 ", fl->fl_pid);
+                seq_printf(f, "%d <none>:0 ", fl->fl_pid);
         }
         if (IS_POSIX(fl)) {
                 if (fl->fl_end == OFFSET_MAX)
-                        out += sprintf(out, "%Ld EOF\n", fl->fl_start);
+                        seq_printf(f, "%Ld EOF\n", fl->fl_start);
                 else
-                        out += sprintf(out, "%Ld %Ld\n", fl->fl_start,
-                                        fl->fl_end);
+                        seq_printf(f, "%Ld %Ld\n", fl->fl_start, fl->fl_end);
         } else {
-                out += sprintf(out, "0 EOF\n");
+                seq_printf(f, "0 EOF\n");
         }
 }
 
-static void move_lock_status(char **p, off_t* pos, off_t offset)
+static int locks_show(struct seq_file *f, void *v)
 {
-        int len;
-        len = strlen(*p);
-        if(*pos >= offset) {
-                /* the complete line is valid */
-                *p += len;
-                *pos += len;
-                return;
-        }
-        if(*pos+len > offset) {
-                /* use the second part of the line */
-                int i = offset-*pos;
-                memmove(*p,*p+i,len-i);
-                *p += len-i;
-                *pos += len;
-                return;
-        }
-        /* discard the complete line */
-        *pos += len;
-}
+        struct file_lock *fl, *bfl;
 
-/**
- *      get_locks_status        -       reports lock usage in /proc/locks
- *      @buffer: address in userspace to write into
- *      @start: ?
- *      @offset: how far we are through the buffer
- *      @length: how much to read
- */
+        fl = list_entry(v, struct file_lock, fl_link);
 
-int get_locks_status(char *buffer, char **start, off_t offset, int length)
-{
-        struct file_lock *fl;
-        char *q = buffer;
-        off_t pos = 0;
-        int i = 0;
+        lock_get_status(f, fl, (long)f->private, "");
 
-        lock_kernel();
-        list_for_each_entry(fl, &file_lock_list, fl_link) {
-                struct file_lock *bfl;
+        list_for_each_entry(bfl, &fl->fl_block, fl_block)
+                lock_get_status(f, bfl, (long)f->private, " ->");
 
-                lock_get_status(q, fl, ++i, "");
-                move_lock_status(&q, &pos, offset);
+        f->private++;
+        return 0;
+}
 
-                if(pos >= offset+length)
-                        goto done;
+static void *locks_start(struct seq_file *f, loff_t *pos)
+{
+        lock_kernel();
+        f->private = (void *)1;
+        return seq_list_start(&file_lock_list, *pos);
+}
 
-                list_for_each_entry(bfl, &fl->fl_block, fl_block) {
-                        lock_get_status(q, bfl, i, " ->");
-                        move_lock_status(&q, &pos, offset);
+static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
+{
+        return seq_list_next(v, &file_lock_list, pos);
+}
 
-                        if(pos >= offset+length)
-                                goto done;
-                }
-        }
-done:
+static void locks_stop(struct seq_file *f, void *v)
+{
         unlock_kernel();
-        *start = buffer;
-        if(q-buffer < length)
-                return (q-buffer);
-        return length;
 }
 
+struct seq_operations locks_seq_operations = {
+        .start  = locks_start,
+        .next   = locks_next,
+        .stop   = locks_stop,
+        .show   = locks_show,
+};
+#endif
+
 /**
  *      lock_may_read - checks that the region is free of locks
  *      @inode: the inode that is being read
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index bee251cb87c8..c9d6d5f400ad 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -66,7 +66,6 @@ extern int get_stram_list(char *);
 extern int get_filesystem_list(char *);
 extern int get_exec_domain_list(char *);
 extern int get_dma_list(char *);
-extern int get_locks_status (char *, char **, off_t, int);
 
 static int proc_calc_metrics(char *page, char **start, off_t off,
                                  int count, int *eof, int len)
@@ -617,16 +616,18 @@ static int cmdline_read_proc(char *page, char **start, off_t off,
         return proc_calc_metrics(page, start, off, count, eof, len);
 }
 
-static int locks_read_proc(char *page, char **start, off_t off,
-                                 int count, int *eof, void *data)
+static int locks_open(struct inode *inode, struct file *filp)
 {
-        int len = get_locks_status(page, start, off, count);
-
-        if (len < count)
-                *eof = 1;
-        return len;
+        return seq_open(filp, &locks_seq_operations);
 }
 
+static const struct file_operations proc_locks_operations = {
+        .open           = locks_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release,
+};
+
 static int execdomains_read_proc(char *page, char **start, off_t off,
                                  int count, int *eof, void *data)
 {
@@ -684,7 +685,6 @@ void __init proc_misc_init(void)
 #endif
                 {"filesystems", filesystems_read_proc},
                 {"cmdline",     cmdline_read_proc},
-                {"locks",       locks_read_proc},
                 {"execdomains", execdomains_read_proc},
                 {NULL,}
         };
@@ -702,6 +702,7 @@ void __init proc_misc_init(void)
                         entry->proc_fops = &proc_kmsg_operations;
         }
 #endif
+        create_seq_entry("locks", 0, &proc_locks_operations);
         create_seq_entry("devices", 0, &proc_devinfo_operations);
         create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations);
 #ifdef CONFIG_BLOCK
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f5075e0e7301..4f1e8cebea78 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -883,6 +883,7 @@ extern int vfs_setlease(struct file *, long, struct file_lock **);
 extern int lease_modify(struct file_lock **, int);
 extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
 extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
+extern struct seq_operations locks_seq_operations;
 
 struct fasync_struct {
         int     magic;