[PATCH 02/15] block: refactor disk_update_readahead

Christoph Hellwig
2024-01-22T17:36:56Z

Factor out a blk_apply_bdi_limits limits helper that can be used with
an explicit queue_limits argument, which will be useful later.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-settings.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 06ea91e51b8b2e..e872b0e168525e 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -85,6 +85,17 @@ void blk_set_stacking_limits(struct queue_limits *lim)
}
EXPORT_SYMBOL(blk_set_stacking_limits);

+static void blk_apply_bdi_limits(struct backing_dev_info *bdi,
+ struct queue_limits *lim)
+{
+ /*
+ * For read-ahead of large files to be effective, we need to read ahead
+ * at least twice the optimal I/O size.
+ */
+ bdi->ra_pages = max(lim->io_opt * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
+ bdi->io_pages = lim->max_sectors >> (PAGE_SHIFT - 9);
+}
+
/**
* blk_queue_bounce_limit - set bounce buffer limit for queue
* @q: the request queue for the device
@@ -393,15 +404,7 @@ EXPORT_SYMBOL(blk_queue_alignment_offset);

void disk_update_readahead(struct gendisk *disk)
{
- struct request_queue *q = disk->queue;
-
- /*
- * For read-ahead of large files to be effective, we need to read ahead
- * at least twice the optimal I/O size.
- */
- disk->bdi->ra_pages =
- max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
- disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9);
+ blk_apply_bdi_limits(disk->bdi, &disk->queue->limits);
}
EXPORT_SYMBOL_GPL(disk_update_readahead);

--
2.39.2