xfs: don't block on buffer read errors

xfs_buf_read() fails to detect dispatch errors before attempting to
wait on sychronous IO. If there was an error, it will get stuck
forever, waiting for an I/O that was never started. Make sure the
error is detected correctly.

Further, such a failure can leave locked pages in the page cache
which will cause a later operation to hang on the page. Ensure that
we correctly process pages in the buffers when we get a dispatch
error.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Dave Chinner 2010-07-20 17:52:59 +10:00 committed by Alex Elder
parent a4190f90b4
commit ec53d1dbb3

View File

@ -578,9 +578,9 @@ _xfs_buf_read(
XBF_READ_AHEAD | _XBF_RUN_QUEUES);
status = xfs_buf_iorequest(bp);
if (!status && !(flags & XBF_ASYNC))
status = xfs_buf_iowait(bp);
return status;
if (status || XFS_BUF_ISERROR(bp) || (flags & XBF_ASYNC))
return status;
return xfs_buf_iowait(bp);
}
xfs_buf_t *
@ -1280,8 +1280,19 @@ submit_io:
if (size)
goto next_chunk;
} else {
bio_put(bio);
/*
* if we get here, no pages were added to the bio. However,
* we can't just error out here - if the pages are locked then
* we have to unlock them otherwise we can hang on a later
* access to the page.
*/
xfs_buf_ioerror(bp, EIO);
if (bp->b_flags & _XBF_PAGE_LOCKED) {
int i;
for (i = 0; i < bp->b_page_count; i++)
unlock_page(bp->b_pages[i]);
}
bio_put(bio);
}
}