This fixes a WARN backtrace in mark_buffer_dirty() that occurs during unmount when the underlying block device is removed. This bug has been seen on System Z when removing all paths from a multipath-backed ext3 mount; on System P when injecting enough PCI EEH errors to make the SCSI controller go offline; and similar warnings have been seen (and patched) with ext2/ext4. 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: Darrick J. Wong <djwong@xxxxxxxxxx> --- fs/ext3/super.c | 24 +++++++++++++++++++++++- fs/jbd/journal.c | 30 ++++++++++++++++++++++++++++-- 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 5dbf4db..5a19796 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -2361,6 +2361,21 @@ static int ext3_commit_super(struct super_block *sb, if (!sbh) return error; + + 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 "ext3: previous I/O error to " + "superblock detected for %s.\n", sb->s_id); + clear_buffer_write_io_error(sbh); + set_buffer_uptodate(sbh); + } /* * If the file system is mounted read-only, don't update the * superblock write time. This avoids updating the superblock @@ -2377,8 +2392,15 @@ static int ext3_commit_super(struct super_block *sb, es->s_free_inodes_count = cpu_to_le32(ext3_count_free_inodes(sb)); BUFFER_TRACE(sbh, "marking dirty"); mark_buffer_dirty(sbh); - if (sync) + if (sync) { error = sync_dirty_buffer(sbh); + if (buffer_write_io_error(sbh)) { + printk(KERN_ERR "ext3: I/O error while writing " + "superblock for %s.\n", sb->s_id); + clear_buffer_write_io_error(sbh); + set_buffer_uptodate(sbh); + } + } return error; } diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c index 2c4b1f1..8bfd226 100644 --- a/fs/jbd/journal.c +++ b/fs/jbd/journal.c @@ -84,6 +84,7 @@ EXPORT_SYMBOL(journal_force_commit); static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); static void __journal_abort_soft (journal_t *journal, int errno); +static const char *journal_dev_name(journal_t *journal, char *buffer); /* * Helper function used to manage commit timeouts @@ -1010,6 +1011,23 @@ void journal_update_superblock(journal_t *journal, int wait) goto out; } + if (buffer_write_io_error(bh)) { + char b[BDEVNAME_SIZE]; + /* + * Oh, dear. A previous attempt to write the journal + * 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 "JBD: previous I/O error detected " + "for journal superblock update for %s.\n", + journal_dev_name(journal, b)); + clear_buffer_write_io_error(bh); + set_buffer_uptodate(bh); + } + spin_lock(&journal->j_state_lock); jbd_debug(1,"JBD: updating superblock (start %u, seq %d, errno %d)\n", journal->j_tail, journal->j_tail_sequence, journal->j_errno); @@ -1021,9 +1039,17 @@ void journal_update_superblock(journal_t *journal, int wait) BUFFER_TRACE(bh, "marking dirty"); mark_buffer_dirty(bh); - if (wait) + if (wait) { sync_dirty_buffer(bh); - else + if (buffer_write_io_error(bh)) { + char b[BDEVNAME_SIZE]; + printk(KERN_ERR "JBD: I/O error detected " + "when updating journal superblock for %s.\n", + journal_dev_name(journal, b)); + clear_buffer_write_io_error(bh); + set_buffer_uptodate(bh); + } + } else write_dirty_buffer(bh, WRITE); out: -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html