Convert /proc/swaps to use seq_file API

diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index cbafa4129498c0f244299342b3e6d0124f2dd65f..f7a0f3b909f840727340f6366da40fa02ecbb8c8 100644 (file)
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -295,6 +295,18 @@ static struct file_operations proc_partitions_operations = {
        .release        = seq_release,
 };
 
+extern struct seq_operations swaps_op;
+static int swaps_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &swaps_op);
+}
+static struct file_operations proc_swaps_operations = {
+       .open           = swaps_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
 #ifdef CONFIG_MODULES
 extern struct seq_operations modules_op;
 static int modules_open(struct inode *inode, struct file *file)
@@ -503,13 +515,6 @@ static int execdomains_read_proc(char *page, char **start, off_t off,
        return proc_calc_metrics(page, start, off, count, eof, len);
 }
 
-static int swaps_read_proc(char *page, char **start, off_t off,
-                                int count, int *eof, void *data)
-{
-       int len = get_swaparea_info(page);
-       return proc_calc_metrics(page, start, off, count, eof, len);
-}
-
 static int memory_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
 {
@@ -616,7 +621,6 @@ void __init proc_misc_init(void)
                {"rtc",         ds1286_read_proc},
 #endif
                {"locks",       locks_read_proc},
-               {"swaps",       swaps_read_proc},
                {"iomem",       memory_read_proc},
                {"execdomains", execdomains_read_proc},
                {NULL,}
@@ -632,6 +636,7 @@ void __init proc_misc_init(void)
                entry->proc_fops = &proc_kmsg_operations;
        create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations);
        create_seq_entry("partitions", 0, &proc_partitions_operations);
+       create_seq_entry("swaps", 0, &proc_swaps_operations);
 #if !defined(CONFIG_ARCH_S390)
        create_seq_entry("interrupts", 0, &proc_interrupts_operations);
 #endif

diff --git a/mm/swapfile.c b/mm/swapfile.c
index bd308fe5991fdfe9bd20732849eff0a36fec4f84..10483a9dba21291e1ed274b8272c1547121b29d7 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -5,6 +5,7 @@
  *  Swap reorganised 29.12.95, Stephen Tweedie
  */
 
+#include <linux/config.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/kernel_stat.h>
@@ -15,6 +16,7 @@
 #include <linux/shm.h>
 #include <linux/blkdev.h>
 #include <linux/buffer_head.h>
+#include <linux/seq_file.h>
 
 #include <asm/pgtable.h>
 #include <linux/swapops.h>
@@ -1041,46 +1043,92 @@ out:
        return err;
 }
 
-int get_swaparea_info(char *buf)
+#ifdef CONFIG_PROC_FS
+/* iterator */
+static void *swap_start(struct seq_file *swap, loff_t *pos)
 {
-       char * page = (char *) __get_free_page(GFP_KERNEL);
        struct swap_info_struct *ptr = swap_info;
-       int i, len;
+       int i;
+       loff_t l = *pos;
+       char * page = (char *) __get_free_page(GFP_KERNEL);
 
-       if (!page)
-               return -ENOMEM;
+       swap->private = page;   /* save for swap_show */
+       swap_list_lock();
 
-       len = sprintf(buf, "Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
-       for (i = 0 ; i < nr_swapfiles ; i++, ptr++) {
-               int j, usedswap;
-               struct file *file;
-               char *path;
+       if (!page)
+               return ERR_PTR(-ENOMEM);
 
+       for (i = 0; i < nr_swapfiles; i++, ptr++) {
                if (!(ptr->flags & SWP_USED) || !ptr->swap_map)
                        continue;
+               if (!l--)
+                       return ptr;
+       }
 
-               file = ptr->swap_file;
-               path = d_path(file->f_dentry, file->f_vfsmnt, page, PAGE_SIZE);
-               for (j = 0,usedswap = 0; j < ptr->max; ++j)
-                       switch (ptr->swap_map[j]) {
-                               case SWAP_MAP_BAD:
-                               case 0:
-                                       continue;
-                               default:
-                                       usedswap++;
-                       }
-               len += sprintf(buf + len, "%-39s %s\t%d\t%d\t%d\n",
-                              path,
-                              S_ISBLK(file->f_dentry->d_inode->i_mode) ?
-                                       "partition" : "file\t",
-                              ptr->pages << (PAGE_SHIFT - 10),
-                              usedswap << (PAGE_SHIFT - 10),
-                              ptr->prio);
+       return NULL;
+}
+
+static void *swap_next(struct seq_file *swap, void *v, loff_t *pos)
+{
+       struct swap_info_struct *ptr = v;
+       void *endptr = (void *) swap_info + nr_swapfiles * sizeof(struct swap_info_struct);
+
+       for (++ptr; ptr < (struct swap_info_struct *) endptr; ptr++) {
+               if (!(ptr->flags & SWP_USED) || !ptr->swap_map)
+                       continue;
+               ++*pos;
+               return ptr;
        }
-       free_page((unsigned long) page);
-       return len;
+
+       return NULL;
 }
 
+static void swap_stop(struct seq_file *swap, void *v)
+{
+       swap_list_unlock();
+       free_page((unsigned long) swap->private);
+       swap->private = NULL;
+}
+
+static int swap_show(struct seq_file *swap, void *v)
+{
+       struct swap_info_struct *ptr = v;
+       int j, usedswap;
+       struct file *file;
+       char *path;
+
+       if (v == swap_info)
+               seq_puts(swap, "Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
+
+       file = ptr->swap_file;
+       path = d_path(file->f_dentry, file->f_vfsmnt, swap->private, PAGE_SIZE);
+
+       for (j = 0, usedswap = 0; j < ptr->max; ++j)
+               switch (ptr->swap_map[j]) {
+                       case SWAP_MAP_BAD:
+                       case 0:
+                               continue;
+                       default:
+                               usedswap++;
+               }
+       seq_printf(swap, "%-39s %s\t%d\t%d\t%d\n",
+                      path,
+                      S_ISBLK(file->f_dentry->d_inode->i_mode) ?
+                               "partition" : "file\t",
+                      ptr->pages << (PAGE_SHIFT - 10),
+                      usedswap << (PAGE_SHIFT - 10),
+                      ptr->prio);
+       return 0;
+}
+
+struct seq_operations swaps_op = {
+       .start =        swap_start,
+       .next =         swap_next,
+       .stop =         swap_stop,
+       .show =         swap_show
+};
+#endif /* CONFIG_PROC_FS */
+
 /*
  * Written 01/25/92 by Simmule Turner, heavily changed by Linus.
  *