block: don't call bio_uninit from bio_endio

Commit b222dd2fdd53 ("block: call bio_uninit in bio_endio") added a call
to bio_uninit in bio_endio to work around callers that use bio_init but
fail to call bio_uninit after they are done to release the resources.
While this is an abuse of the bio_init API we still have quite a few of
those left.  But this early uninit causes a problem for integrity data,
as at least some users need the bio_integrity_payload.  Right now the
only one is the NVMe passthrough which archives this by adding a special
case to skip the freeing if the BIP_INTEGRITY_USER flag is set.

Sort this out by only putting bi_blkg in bio_endio as that is the cause
of the actual leaks - the few users of the crypto context and integrity
data all properly call bio_uninit, usually through bio_put for
dynamically allocated bios.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240702151047.1746127-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bio.c b/block/bio.c
index 4ca3f31ce45fb59825b43c468622855b77d45fe2..68ce75fd9b7c897f96fcb733c0b9b4b9a25e9716 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1630,8 +1630,18 @@ again:
                goto again;
        }
 
-       /* release cgroup info */
-       bio_uninit(bio);
+#ifdef CONFIG_BLK_CGROUP
+       /*
+        * Release cgroup info.  We shouldn't have to do this here, but quite
+        * a few callers of bio_init fail to call bio_uninit, so we cover up
+        * for that here at least for now.
+        */
+       if (bio->bi_blkg) {
+               blkg_put(bio->bi_blkg);
+               bio->bi_blkg = NULL;
+       }
+#endif
+
        if (bio->bi_end_io)
                bio->bi_end_io(bio);
 }