xfs: don't block on buffer read errors (ec53d1db) · Commits · 戴 / test

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>

fs/xfs/linux-2.6/xfs_buf.c

+15 −4

Original line number	Diff line number	Diff line
		@@ -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);
		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);
		}
		}

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