[PATCH 15/45] block: change the hash used for looking up block devices

Christoph Hellwig
2020-11-28T22:11:07Z

Adding the minor to the major creates tons of pointless conflicts. Just
use the dev_t itself, which is 32-bits and thus is guaranteed to fit
into ino_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
---
fs/block_dev.c | 26 ++------------------------
1 file changed, 2 insertions(+), 24 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index c5755150c6be62..d707ab376da86e 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -863,35 +863,12 @@ void __init bdev_cache_init(void)
blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */
}

-/*
- * Most likely _very_ bad one - but then it's hardly critical for small
- * /dev and can be fixed when somebody will need really large one.
- * Keep in mind that it will be fed through icache hash function too.
- */
-static inline unsigned long hash(dev_t dev)
-{
- return MAJOR(dev)+MINOR(dev);
-}
-
-static int bdev_test(struct inode *inode, void *data)
-{
- return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data;
-}
-
-static int bdev_set(struct inode *inode, void *data)
-{
- BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data;
- return 0;
-}
-
static struct block_device *bdget(dev_t dev)
{
struct block_device *bdev;
struct inode *inode;

- inode = iget5_locked(blockdev_superblock, hash(dev),
- bdev_test, bdev_set, &dev);
-
+ inode = iget_locked(blockdev_superblock, dev);
if (!inode)
return NULL;

@@ -903,6 +880,7 @@ static struct block_device *bdget(dev_t dev)
bdev->bd_super = NULL;
bdev->bd_inode = inode;
bdev->bd_part_count = 0;
+ bdev->bd_dev = dev;
inode->i_mode = S_IFBLK;
inode->i_rdev = dev;
inode->i_bdev = bdev;
--
2.29.2