block: export blk_validate_limits

While block drivers do the validation as part of committing them to the
queue, users that use the limit outside of a block device context have
to validate the limits and fill in the calculated values as well.

So far btrfs is the only user of queue limits without a block device,
and it has gotten away with that more or less by accident.  But with
commit 559218d43ec9 ("block: pre-calculate max_zone_append_sectors")
this became fatal for setups that have small max zone append size,
as it won't be limited now.

Export blk_validate_limits so that it can be called directly from btrfs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20241113084541.34315-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 7d6b296997c2cbc1ab574296ce8b24fc4bafaa28..f1d4dfdc37a71a5401b9742a599070926edb3174 100644 (file)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -222,7 +222,7 @@ unsupported:
  * Check that the limits in lim are valid, initialize defaults for unset
  * values, and cap values based on others where needed.
  */
-static int blk_validate_limits(struct queue_limits *lim)
+int blk_validate_limits(struct queue_limits *lim)
 {
        unsigned int max_hw_sectors;
        unsigned int logical_block_sectors;
@@ -365,6 +365,7 @@ static int blk_validate_limits(struct queue_limits *lim)
                return err;
        return blk_validate_zoned_limits(lim);
 }
+EXPORT_SYMBOL_GPL(blk_validate_limits);
 
 /*
  * Set the default limits for a newly allocated queue.  @lim contains the

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 65f37ae7071260b978ab13365c2711a6dfa0e2ec..cd905afaf51a055805ef8b41ca9b9fe6c9a87f45 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -948,6 +948,7 @@ queue_limits_start_update(struct request_queue *q)
 int queue_limits_commit_update(struct request_queue *q,
                struct queue_limits *lim);
 int queue_limits_set(struct request_queue *q, struct queue_limits *lim);
+int blk_validate_limits(struct queue_limits *lim);
 
 /**
  * queue_limits_cancel_update - cancel an atomic update of queue limits