Don't decrement bi_size in bio_endio
The only caller of bio_endio that does not pass the full bi_size
is end_that_request_first. Also, no ->bi_end_io method is really
interested in bi_size being decremented.
So move the decrement and related code into ll_rw_blk and merge it
with order_bio_endio to form req_bio_endio which does endio functionality
specific to request completion.
As some ->bi_end_io methods do check bi_size of 0, we set it thus for
now, but that will go in the next patch.
Signed-off-by: Neil Brown <neilb@suse.de>
### Diffstat output
./block/ll_rw_blk.c | 42 +++++++++++++++++++++++++++---------------
./fs/bio.c | 23 +++++++++++------------
2 files changed, 38 insertions(+), 27 deletions(-)
diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index dfe0948..b55ed0d 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -527,22 +527,36 @@
return 1;
}
-static int ordered_bio_endio(struct request *rq, struct bio *bio,
- unsigned int nbytes, int error)
+static void req_bio_endio(struct request *rq, struct bio *bio,
+ unsigned int nbytes, int error)
{
struct request_queue *q = rq->q;
- if (&q->bar_rq != rq)
- return 0;
+ if (&q->bar_rq != rq) {
+ if (error)
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+ error = -EIO;
- /*
- * Okay, this is the barrier request in progress, just
- * record the error;
- */
- if (error && !q->orderr)
- q->orderr = error;
+ if (unlikely(nbytes > bio->bi_size)) {
+ printk("%s: want %u bytes done, only %u left\n",
+ __FUNCTION__, nbytes, bio->bi_size);
+ nbytes = bio->bi_size;
+ }
- return 1;
+ bio->bi_size -= nbytes;
+ bio->bi_sector += (nbytes >> 9);
+ if (bio->bi_size == 0)
+ bio_endio(bio, bio->bi_size, error);
+ } else {
+
+ /*
+ * Okay, this is the barrier request in progress, just
+ * record the error;
+ */
+ if (error && !q->orderr)
+ q->orderr = error;
+ }
}
/**
@@ -3388,8 +3402,7 @@
if (nr_bytes >= bio->bi_size) {
req->bio = bio->bi_next;
nbytes = bio->bi_size;
- if (!ordered_bio_endio(req, bio, nbytes, error))
- bio_endio(bio, nbytes, error);
+ req_bio_endio(req, bio, nbytes, error);
next_idx = 0;
bio_nbytes = 0;
} else {
@@ -3444,8 +3457,7 @@
* if the request wasn't completed, update state
*/
if (bio_nbytes) {
- if (!ordered_bio_endio(req, bio, bio_nbytes, error))
- bio_endio(bio, bio_nbytes, error);
+ req_bio_endio(req, bio, bio_nbytes, error);
bio->bi_idx += next_idx;
bio_iovec(bio)->bv_offset += nr_bytes;
bio_iovec(bio)->bv_len -= nr_bytes;
diff --git a/fs/bio.c b/fs/bio.c
index 5720b94..3adecd6 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1006,13 +1006,14 @@
* @error: error, if any
*
* Description:
- * bio_endio() will end I/O on @bytes_done number of bytes. This may be
- * just a partial part of the bio, or it may be the whole bio. bio_endio()
- * is the preferred way to end I/O on a bio, it takes care of decrementing
- * bi_size and clearing BIO_UPTODATE on error. @error is 0 on success, and
- * and one of the established -Exxxx (-EIO, for instance) error values in
- * case something went wrong. Noone should call bi_end_io() directly on
- * a bio unless they own it and thus know that it has an end_io function.
+ * bio_endio() will end I/O on @bytes_done number of bytes. This
+ * must always be the whole (remaining) bio. bio_endio() is the
+ * preferred way to end I/O on a bio, it takes care of clearing
+ * BIO_UPTODATE on error. @error is 0 on success, and and one of the
+ * established -Exxxx (-EIO, for instance) error values in case
+ * something went wrong. Noone should call bi_end_io() directly on a
+ * bio unless they own it and thus know that it has an end_io
+ * function.
**/
void bio_endio(struct bio *bio, unsigned int bytes_done, int error)
{
@@ -1021,16 +1022,14 @@
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
error = -EIO;
- if (unlikely(bytes_done > bio->bi_size)) {
+ if (unlikely(bytes_done != bio->bi_size)) {
printk("%s: want %u bytes done, only %u left\n", __FUNCTION__,
bytes_done, bio->bi_size);
bytes_done = bio->bi_size;
}
- bio->bi_size -= bytes_done;
- bio->bi_sector += (bytes_done >> 9);
-
- if (bio->bi_size && bio->bi_end_io)
+ bio->bi_size = 0; /* expected by some callees - will be removed */
+ if (bio->bi_end_io)
bio->bi_end_io(bio, bytes_done, error);
}