block: Replace bi_integrity with bi_special
For commands like REQ_COPY we need a way to pass extra information along
with each bio. Like integrity metadata this information must be
available at the bottom of the stack so bi_private does not suffice.
Rename the existing bi_integrity field to bi_special and make it a union
so we can have different bio extensions for each class of command.
We previously used bi_integrity != NULL as a way to identify whether a
bio had integrity metadata or not. Introduce a REQ_INTEGRITY to be the
indicator now that bi_special can contain different things.
In addition, bio_integrity(bio) will now return a pointer to the
integrity payload (when applicable).
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/Documentation/block/data-integrity.txt b/Documentation/block/data-integrity.txt
index b4eacf4..4d4de8b 100644
--- a/Documentation/block/data-integrity.txt
+++ b/Documentation/block/data-integrity.txt
@@ -129,11 +129,11 @@
4.1 BIO
The data integrity patches add a new field to struct bio when
-CONFIG_BLK_DEV_INTEGRITY is enabled. bio->bi_integrity is a pointer
-to a struct bip which contains the bio integrity payload. Essentially
-a bip is a trimmed down struct bio which holds a bio_vec containing
-the integrity metadata and the required housekeeping information (bvec
-pool, vector count, etc.)
+CONFIG_BLK_DEV_INTEGRITY is enabled. bio_integrity(bio) returns a
+pointer to a struct bip which contains the bio integrity payload.
+Essentially a bip is a trimmed down struct bio which holds a bio_vec
+containing the integrity metadata and the required housekeeping
+information (bvec pool, vector count, etc.)
A kernel subsystem can enable data integrity protection on a bio by
calling bio_integrity_alloc(bio). This will allocate and attach the