This is a note to let you know that I've just added the patch titled
rbd: fix I/O error propagation for reads
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rbd-fix-i-o-error-propagation-for-reads.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 17c1cc1d9293a568a00545469078e29555cc7f39 Mon Sep 17 00:00:00 2001
From: Josh Durgin <josh.durgin@xxxxxxxxxxx>
Date: Mon, 26 Aug 2013 17:55:38 -0700
Subject: rbd: fix I/O error propagation for reads
From: Josh Durgin <josh.durgin@xxxxxxxxxxx>
commit 17c1cc1d9293a568a00545469078e29555cc7f39 upstream.
When a request returns an error, the driver needs to report the entire
extent of the request as completed. Writes already did this, since
they always set xferred = length, but reads were skipping that step if
an error other than -ENOENT occurred. Instead, rbd would end up
passing 0 xferred to blk_end_request(), which would always report
needing more data. This resulted in an assert failing when more data
was required by the block layer, but all the object requests were
done:
[ 1868.719077] rbd: obj_request read result -108 xferred 0
[ 1868.719077]
[ 1868.719518] end_request: I/O error, dev rbd1, sector 0
[ 1868.719739]
[ 1868.719739] Assertion failure in rbd_img_obj_callback() at line 1736:
[ 1868.719739]
[ 1868.719739] rbd_assert(more ^ (which == img_request->obj_request_count));
Without this assert, reads that hit errors would hang forever, since
the block layer considered them incomplete.
Fixes: http://tracker.ceph.com/issues/5647
Signed-off-by: Josh Durgin <josh.durgin@xxxxxxxxxxx>
Reviewed-by: Alex Elder <alex.elder@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/rbd.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1565,11 +1565,12 @@ rbd_img_obj_request_read_callback(struct
obj_request, obj_request->img_request, obj_request->result,
xferred, length);
/*
- * ENOENT means a hole in the image. We zero-fill the
- * entire length of the request. A short read also implies
- * zero-fill to the end of the request. Either way we
- * update the xferred count to indicate the whole request
- * was satisfied.
+ * ENOENT means a hole in the image. We zero-fill the entire
+ * length of the request. A short read also implies zero-fill
+ * to the end of the request. An error requires the whole
+ * length of the request to be reported finished with an error
+ * to the block layer. In each case we update the xferred
+ * count to indicate the whole request was satisfied.
*/
rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
if (obj_request->result == -ENOENT) {
@@ -1578,14 +1579,13 @@ rbd_img_obj_request_read_callback(struct
else
zero_pages(obj_request->pages, 0, length);
obj_request->result = 0;
- obj_request->xferred = length;
} else if (xferred < length && !obj_request->result) {
if (obj_request->type == OBJ_REQUEST_BIO)
zero_bio_chain(obj_request->bio_list, xferred);
else
zero_pages(obj_request->pages, xferred, length);
- obj_request->xferred = length;
}
+ obj_request->xferred = length;
obj_request_done_set(obj_request);
}
Patches currently in stable-queue which might be from josh.durgin@xxxxxxxxxxx are
queue-3.10/rbd-fix-i-o-error-propagation-for-reads.patch
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