jbd2: Add barrier not supported test to journal_wait_on_commit_record

Xen doesn't report that barriers are not supported until buffer I/O is
reported as completed, instead of when the buffer I/O is submitted.
Add a check and a fallback codepath to journal_wait_on_commit_record()
to detect this case, so that attempts to mount ext4 filesystems on
LVM/devicemapper devices on Xen guests don't blow up with an "Aborting
journal on device XXX"; "Remounting filesystem read-only" error.

Thanks to Andreas Sundstrom for reporting this issue.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
This commit is contained in:
Theodore Ts'o 2009-01-05 21:34:13 -05:00
parent 0390131ba8
commit fd98496f46
1 changed files with 25 additions and 2 deletions

View File

@ -25,6 +25,7 @@
#include <linux/crc32.h>
#include <linux/writeback.h>
#include <linux/backing-dev.h>
#include <linux/bio.h>
/*
* Default IO end handler for temporary BJ_IO buffer_heads.
@ -168,12 +169,34 @@ static int journal_submit_commit_record(journal_t *journal,
* This function along with journal_submit_commit_record
* allows to write the commit record asynchronously.
*/
static int journal_wait_on_commit_record(struct buffer_head *bh)
static int journal_wait_on_commit_record(journal_t *journal,
struct buffer_head *bh)
{
int ret = 0;
retry:
clear_buffer_dirty(bh);
wait_on_buffer(bh);
if (buffer_eopnotsupp(bh) && (journal->j_flags & JBD2_BARRIER)) {
printk(KERN_WARNING
"JBD2: wait_on_commit_record: sync failed on %s - "
"disabling barriers\n", journal->j_devname);
spin_lock(&journal->j_state_lock);
journal->j_flags &= ~JBD2_BARRIER;
spin_unlock(&journal->j_state_lock);
lock_buffer(bh);
clear_buffer_dirty(bh);
set_buffer_uptodate(bh);
bh->b_end_io = journal_end_buffer_io_sync;
ret = submit_bh(WRITE_SYNC, bh);
if (ret) {
unlock_buffer(bh);
return ret;
}
goto retry;
}
if (unlikely(!buffer_uptodate(bh)))
ret = -EIO;
@ -799,7 +822,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
__jbd2_journal_abort_hard(journal);
}
if (!err && !is_journal_aborted(journal))
err = journal_wait_on_commit_record(cbh);
err = journal_wait_on_commit_record(journal, cbh);
if (err)
jbd2_journal_abort(journal, err);