ext2: clear uptodate flag on super block I/O error
This fixes a WARN backtrace in mark_buffer_dirty() that occurs during
unmount when a USB or floppy device is removed. I reported this a kernel
regression, but looks like it might have been there for longer
than that.
The super block update from a previous operation has marked the buffer
as in error, and the flag has to be cleared before doing the update.
(Similar code already exists in ext4).
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 0faf770..1388802 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -1137,8 +1137,24 @@
static int ext2_sync_fs(struct super_block *sb, int wait)
{
struct ext2_super_block *es = EXT2_SB(sb)->s_es;
+ struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
lock_kernel();
+ 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.
+ */
+ ext2_msg(sb, KERN_ERR,
+ "previous I/O error to superblock detected\n");
+ clear_buffer_write_io_error(sbh);
+ set_buffer_uptodate(sbh);
+ }
+
if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
ext2_debug("setting valid to 0\n");
es->s_state &= cpu_to_le16(~EXT2_VALID_FS);