an issue of ext4

["Zhang, Hongchao" <hongchao.zhang@intel.com>]

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Hi,

in ext4_fill_super, the variables related to statfs should be initialized after journal recovery is completed.
otherwise, if a large number of blocks were being allocated before the filesystem crashed, then the blocks
and inode counters may become negative during use and report incorrect values to statfs call.

Thanks
Hongchao

[-- Attachment #2: statfs-issue.patch --]
[-- Type: application/octet-stream, Size: 1737 bytes --]

diff -p -u linux-3.13.5.orig/fs/ext4/super.c linux-3.13.5/fs/ext4/super.c
--- linux-3.13.5.orig/fs/ext4/super.c
+++ linux-3.13.5/fs/ext4/super.c
@@ -3871,27 +3871,6 @@ static int ext4_fill_super(struct super_
 	/* Register extent status tree shrinker */
 	ext4_es_register_shrinker(sbi);
 
-	err = percpu_counter_init(&sbi->s_freeclusters_counter,
-			ext4_count_free_clusters(sb));
-	if (!err) {
-		err = percpu_counter_init(&sbi->s_freeinodes_counter,
-				ext4_count_free_inodes(sb));
-	}
-	if (!err) {
-		err = percpu_counter_init(&sbi->s_dirs_counter,
-				ext4_count_dirs(sb));
-	}
-	if (!err) {
-		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
-	}
-	if (!err) {
-		err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
-	}
-	if (err) {
-		ext4_msg(sb, KERN_ERR, "insufficient memory");
-		goto failed_mount3;
-	}
-
 	sbi->s_stripe = ext4_get_stripe_size(sbi);
 	sbi->s_extent_max_zeroout_kb = 32;
 
@@ -3948,6 +3927,27 @@ static int ext4_fill_super(struct super_
 		goto no_journal;
 	}
 
+	err = percpu_counter_init(&sbi->s_freeclusters_counter,
+			ext4_count_free_clusters(sb));
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_freeinodes_counter,
+				ext4_count_free_inodes(sb));
+	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_dirs_counter,
+				ext4_count_dirs(sb));
+	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
+	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
+	}
+	if (err) {
+		ext4_msg(sb, KERN_ERR, "insufficient memory");
+		goto failed_mount3;
+	}
+
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
 				       JBD2_FEATURE_INCOMPAT_64BIT)) {