diff mbox series

[v2,7/8] block/bdev: lift block size restrictions to 64k

Message ID 20250204231209.429356-8-mcgrof@kernel.org (mailing list archive)
State New
Headers show
Series enable bs > ps for block devices | expand

Commit Message

Luis Chamberlain Feb. 4, 2025, 11:12 p.m. UTC 
We now can support blocksizes larger than PAGE_SIZE, so in theory
we should be able to lift the restriction up to the max supported page
cache order. However bound ourselves to what we can currently validate
and test. Through blktests and fstest we can validate up to 64k today.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 block/bdev.c           | 3 +--
 include/linux/blkdev.h | 9 ++++++++-
 2 files changed, 9 insertions(+), 3 deletions(-)

Comments

Matthew Wilcox Feb. 17, 2025, 10:01 p.m. UTC | #1 
On Tue, Feb 04, 2025 at 03:12:08PM -0800, Luis Chamberlain wrote:
> We now can support blocksizes larger than PAGE_SIZE, so in theory
> we should be able to lift the restriction up to the max supported page
> cache order. However bound ourselves to what we can currently validate
> and test. Through blktests and fstest we can validate up to 64k today.
> 
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 248416ecd01c..a89513302977 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -26,6 +26,7 @@
>  #include <linux/xarray.h>
>  #include <linux/file.h>
>  #include <linux/lockdep.h>
> +#include <linux/pagemap.h>

We can drop this until we actually use 

> + * We should strive for 1 << (PAGE_SHIFT + MAX_PAGECACHE_ORDER)

right?  I don't see anything else that needs this include.
diff mbox series

Patch

diff --git a/block/bdev.c b/block/bdev.c
index 8aadf1f23cb4..22806ce11e1d 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -183,8 +183,7 @@  int sb_set_blocksize(struct super_block *sb, int size)
 {
 	if (set_blocksize(sb->s_bdev_file, size))
 		return 0;
-	/* If we get here, we know size is power of two
-	 * and it's value is between 512 and PAGE_SIZE */
+	/* If we get here, we know size is validated */
 	sb->s_blocksize = size;
 	sb->s_blocksize_bits = blksize_bits(size);
 	return sb->s_blocksize;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 248416ecd01c..a89513302977 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -26,6 +26,7 @@ 
 #include <linux/xarray.h>
 #include <linux/file.h>
 #include <linux/lockdep.h>
+#include <linux/pagemap.h>
 
 struct module;
 struct request_queue;
@@ -267,10 +268,16 @@  static inline dev_t disk_devt(struct gendisk *disk)
 	return MKDEV(disk->major, disk->first_minor);
 }
 
+/*
+ * We should strive for 1 << (PAGE_SHIFT + MAX_PAGECACHE_ORDER)
+ * however we constrain this to what we can validate and test.
+ */
+#define BLK_MAX_BLOCK_SIZE      SZ_64K
+
 /* blk_validate_limits() validates bsize, so drivers don't usually need to */
 static inline int blk_validate_block_size(unsigned long bsize)
 {
-	if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
+	if (bsize < 512 || bsize > BLK_MAX_BLOCK_SIZE || !is_power_of_2(bsize))
 		return -EINVAL;
 
 	return 0;