From 47dd67532303803a87f43195e088b3b4bcf0454d Mon Sep 17 00:00:00 2001 From: Luis Chamberlain Date: Fri, 21 Feb 2025 14:38:22 -0800 Subject: [PATCH] block/bdev: lift block size restrictions to 64k 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 Reviewed-by: "Matthew Wilcox (Oracle)" Signed-off-by: Luis Chamberlain Link: https://lore.kernel.org/r/20250221223823.1680616-8-mcgrof@kernel.org Signed-off-by: Christian Brauner --- block/bdev.c | 3 +-- include/linux/blkdev.h | 8 +++++++- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/block/bdev.c b/block/bdev.c index 8aadf1f23cb4a..22806ce11e1de 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 248416ecd01c9..a97428e8bbbea 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -267,10 +267,16 @@ 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; -- 2.47.3