block: get rid of blk_integrity_revalidate()

Commit 25520d55cd ("block: Inline blk_integrity in struct gendisk")
introduced blk_integrity_revalidate(), which seems to assume ownership
of the stable pages flag and unilaterally clears it if no blk_integrity
profile is registered:

    if (bi->profile)
            disk->queue->backing_dev_info->capabilities |=
                    BDI_CAP_STABLE_WRITES;
    else
            disk->queue->backing_dev_info->capabilities &=
                    ~BDI_CAP_STABLE_WRITES;

It's called from revalidate_disk() and rescan_partitions(), making it
impossible to enable stable pages for drivers that support partitions
and don't use blk_integrity: while the call in revalidate_disk() can be
trivially worked around (see zram, which doesn't support partitions and
hence gets away with zram_revalidate_disk()), rescan_partitions() can
be triggered from userspace at any time.  This breaks rbd, where the
ceph messenger is responsible for generating/verifying CRCs.

Since blk_integrity_{un,}register() "must" be used for (un)registering
the integrity profile with the block layer, move BDI_CAP_STABLE_WRITES
setting there.  This way drivers that call blk_integrity_register() and
use integrity infrastructure won't interfere with drivers that don't
but still want stable pages.

Fixes: 25520d55cd ("block: Inline blk_integrity in struct gendisk")
Cc: "Martin K. Petersen" <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Mike Snitzer <[email protected]>
Cc: [email protected] # 4.4+, needs backporting
Tested-by: Dan Williams <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Ilya Dryomov 2017-04-18 18:43:20 +02:00 • committed by Jens Axboe
commit 19b7ccf865
4 changed files with 2 additions and 21 deletions

View file

@ -417,7 +417,7 @@ void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template
bi->tuple_size = template->tuple_size;
bi->tag_size = template->tag_size;
blk_integrity_revalidate(disk);
disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
}
EXPORT_SYMBOL(blk_integrity_register);
@ -430,26 +430,11 @@ EXPORT_SYMBOL(blk_integrity_register);
*/
void blk_integrity_unregister(struct gendisk *disk)
{
blk_integrity_revalidate(disk);
disk->queue->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
memset(&disk->queue->integrity, 0, sizeof(struct blk_integrity));
}
EXPORT_SYMBOL(blk_integrity_unregister);
void blk_integrity_revalidate(struct gendisk *disk)
{
struct blk_integrity *bi = &disk->queue->integrity;
if (!(disk->flags & GENHD_FL_UP))
return;
if (bi->profile)
disk->queue->backing_dev_info->capabilities |=
BDI_CAP_STABLE_WRITES;
else
disk->queue->backing_dev_info->capabilities &=
~BDI_CAP_STABLE_WRITES;
}
void blk_integrity_add(struct gendisk *disk)
{
if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,