ext2: avoid WARN() messages when failing to write to the superblock

This fixes a common warning reported by kerneloops.org

[Kernel summit hacking hour]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 1388802b7803..f9cb54a585ce 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -1105,9 +1105,30 @@ failed_sbi:
         return ret;
 }
 
+static void ext2_clear_super_error(struct super_block *sb)
+{
+        struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
+
+        if (buffer_write_io_error(sbh)) {
+                /*
+                 * Oh, dear.  A previous attempt to write the
+                 * superblock failed.  This could happen because the
+                 * USB device was yanked out.  Or it could happen to
+                 * be a transient write error and maybe the block will
+                 * be remapped.  Nothing we can do but to retry the
+                 * write and hope for the best.
+                 */
+                printk(KERN_ERR "EXT2-fs: %s previous I/O error to "
+                       "superblock detected", sb->s_id);
+                clear_buffer_write_io_error(sbh);
+                set_buffer_uptodate(sbh);
+        }
+}
+
 static void ext2_commit_super (struct super_block * sb,
                                struct ext2_super_block * es)
 {
+        ext2_clear_super_error(sb);
         es->s_wtime = cpu_to_le32(get_seconds());
         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
         sb->s_dirt = 0;
@@ -1115,6 +1136,7 @@ static void ext2_commit_super (struct super_block * sb,
 
 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
 {
+        ext2_clear_super_error(sb);
         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
         es->s_wtime = cpu_to_le32(get_seconds());