[PATCH] percpu counter data type changes to suppport more than 2**31 ext3 free blocks counter

The percpu counter data type are changed in this set of patches to support
more users like ext3 who need more than 32 bit to store the free blocks
total in the filesystem.

- Generic perpcu counters data type changes.  The size of the global counter
  and local counter were explictly specified using s64 and s32.  The global
  counter is changed from long to s64, while the local counter is changed from
  long to s32, so we could avoid doing 64 bit update in most cases.

- Users of the percpu counters are updated to make use of the new
  percpu_counter_init() routine now taking an additional parameter to allow
  users to pass the initial value of the global counter.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 19 insertions, 17 deletions

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 1a198b3985c9..a60cc6ec130f 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -1580,9 +1580,6 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
                 goto failed_mount;
         }
 
-        percpu_counter_init(&sbi->s_freeblocks_counter);
-        percpu_counter_init(&sbi->s_freeinodes_counter);
-        percpu_counter_init(&sbi->s_dirs_counter);
         bgl_lock_init(&sbi->s_blockgroup_lock);
 
         for (i = 0; i < db_count; i++) {
@@ -1602,6 +1599,14 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
         sbi->s_gdb_count = db_count;
         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
         spin_lock_init(&sbi->s_next_gen_lock);
+
+        percpu_counter_init(&sbi->s_freeblocks_counter,
+                ext3_count_free_blocks(sb));
+        percpu_counter_init(&sbi->s_freeinodes_counter,
+                ext3_count_free_inodes(sb));
+        percpu_counter_init(&sbi->s_dirs_counter,
+                ext3_count_dirs(sb));
+
         /* per fileystem reservation list head & lock */
         spin_lock_init(&sbi->s_rsv_window_lock);
         sbi->s_rsv_window_root = RB_ROOT;
@@ -1640,16 +1645,16 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
         if (!test_opt(sb, NOLOAD) &&
             EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
                 if (ext3_load_journal(sb, es, journal_devnum))
-                        goto failed_mount2;
+                        goto failed_mount3;
         } else if (journal_inum) {
                 if (ext3_create_journal(sb, es, journal_inum))
-                        goto failed_mount2;
+                        goto failed_mount3;
         } else {
                 if (!silent)
                         printk (KERN_ERR
                                 "ext3: No journal on filesystem on %s\n",
                                 sb->s_id);
-                goto failed_mount2;
+                goto failed_mount3;
         }
 
         /* We have now updated the journal if required, so we can
@@ -1672,7 +1677,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
                     (sbi->s_journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)) {
                         printk(KERN_ERR "EXT3-fs: Journal does not support "
                                "requested data journaling mode\n");
-                        goto failed_mount3;
+                        goto failed_mount4;
                 }
         default:
                 break;
@@ -1695,13 +1700,13 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
         if (!sb->s_root) {
                 printk(KERN_ERR "EXT3-fs: get root inode failed\n");
                 iput(root);
-                goto failed_mount3;
+                goto failed_mount4;
         }
         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
                 dput(sb->s_root);
                 sb->s_root = NULL;
                 printk(KERN_ERR "EXT3-fs: corrupt root inode, run e2fsck\n");
-                goto failed_mount3;
+                goto failed_mount4;
         }
 
         ext3_setup_super (sb, es, sb->s_flags & MS_RDONLY);
@@ -1724,13 +1729,6 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
                 test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
                 "writeback");
 
-        percpu_counter_mod(&sbi->s_freeblocks_counter,
-                ext3_count_free_blocks(sb));
-        percpu_counter_mod(&sbi->s_freeinodes_counter,
-                ext3_count_free_inodes(sb));
-        percpu_counter_mod(&sbi->s_dirs_counter,
-                ext3_count_dirs(sb));
-
         lock_kernel();
         return 0;
 
@@ -1740,8 +1738,12 @@ cantfind_ext3:
                        sb->s_id);
         goto failed_mount;
 
-failed_mount3:
+failed_mount4:
         journal_destroy(sbi->s_journal);
+failed_mount3:
+        percpu_counter_destroy(&sbi->s_freeblocks_counter);
+        percpu_counter_destroy(&sbi->s_freeinodes_counter);
+        percpu_counter_destroy(&sbi->s_dirs_counter);
 failed_mount2:
         for (i = 0; i < db_count; i++)
                 brelse(sbi->s_group_desc[i]);