ext3 inode accounting fix

PATCH New Andrew Morton 1 participant 1 message Nov 7, 2002

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Andrew Morton

author

2002-11-07 03:16 UTC #0 lore raw

PATCH 1/1 ext3 inode accounting fix

ext3 in the 2.5.46 kernel is double-counting inodes in the per-blockgroup accounting structures. When a blockgroup fills up this triggers a consistency check and the filesystem is remounted read-only.

There is no data loss, but all ext3 filesystems which have been mounted
read/write under the 2.5.46 kernel will have incorrect accounting. They
must be fixed with a fsck. If this is not done, the filesystem will be remounted read-only at some time in the future - when a blockgroup runs out of inodes and the consistency check detects the error.

Step 1: patch the 2.5.46 kernel with the below fix

Step 2: reboot into the new kernel, forcing a fsck against all ext3
filesystems.

Alternatively, wait for 2.5.47 and then fsck all filesystems. The problem only manifests if all of a blockgroup's inodes are consumed, and that is rare.

fs/ext3/ialloc.c renamed from fs/ext3/ialloc.c~ext3-inodes-count-fix +3 ~~-16~~

@@ -227,11 +227,6 @@ static int find_group_dir(struct super_b
 	}
 	if (!best_desc)
 		return -1;
-	best_desc->bg_free_inodes_count =
-		cpu_to_le16(le16_to_cpu(best_desc->bg_free_inodes_count) - 1);
-	best_desc->bg_used_dirs_count =
-		cpu_to_le16(le16_to_cpu(best_desc->bg_used_dirs_count) + 1);
-	mark_buffer_dirty(best_bh);
 	return best_group;
 }

@@ -355,14 +350,7 @@ fallback:
 	}
 
 	return -1;
-
 found:
-	desc->bg_free_inodes_count =
-		cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) - 1);
-	desc->bg_used_dirs_count =
-		cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) + 1);
-	sbi->s_dir_count++;
-	mark_buffer_dirty(bh);
 	return group;
 }

@@ -410,9 +398,6 @@ static int find_group_other(struct super
 	return -1;
 
 found:
-	desc->bg_free_inodes_count =
-		cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) - 1);
-	mark_buffer_dirty(bh);
 	return group;
 }

@@ -521,9 +506,11 @@ repeat:
 	if (err) goto fail;
 	gdp->bg_free_inodes_count =
 		cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
-	if (S_ISDIR(mode))
+	if (S_ISDIR(mode)) {
 		gdp->bg_used_dirs_count =
 			cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
+		EXT3_SB(sb)->s_dir_count++;
+	}
 	BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
 	err = ext3_journal_dirty_metadata(handle, bh2);
 	if (err) goto fail;