diff options
| author | Qu Wenruo <wqu@suse.com> | 2023-02-17 13:36:58 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-04-17 18:01:14 +0200 |
| commit | a97699d1d610710fb0103addaac3b590716f2de4 (patch) | |
| tree | b47acb103e385484e2f08ba3bf9400d74fccf598 /fs/btrfs/volumes.h | |
| parent | dcb2137c8411d9940ebdfc93bb4de20b7f8fcf42 (diff) | |
btrfs: replace map_lookup->stripe_len by BTRFS_STRIPE_LEN
Currently btrfs doesn't support stripe lengths other than 64KiB.
This is already set in the tree-checker.
There is really no meaning to record that fixed value in map_lookup for
now, and can all be replaced with BTRFS_STRIPE_LEN.
Furthermore we can use the fix stripe length to do the following
optimization:
- Use BTRFS_STRIPE_LEN_SHIFT to replace some 64bit division
Now we only need to do a right shift.
And the value of BTRFS_STRIPE_LEN itself is already too large for bit
shift, thus if we accidentally use BTRFS_STRIPE_LEN to do bit shift,
a compiler warning would be triggered.
Thus this bit shift optimization would be safe.
- Use BTRFS_STRIPE_LEN_MASK to calculate the offset inside a stripe
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/volumes.h')
| -rw-r--r-- | fs/btrfs/volumes.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 7e51f2238f72..9f397b4c1b4f 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -17,7 +17,11 @@ extern struct mutex uuid_mutex; -#define BTRFS_STRIPE_LEN SZ_64K +#define BTRFS_STRIPE_LEN SZ_64K +#define BTRFS_STRIPE_LEN_SHIFT (16) +#define BTRFS_STRIPE_LEN_MASK (BTRFS_STRIPE_LEN - 1) + +static_assert(const_ilog2(BTRFS_STRIPE_LEN) == BTRFS_STRIPE_LEN_SHIFT); /* Used by sanity check for btrfs_raid_types. */ #define const_ffs(n) (__builtin_ctzll(n) + 1) @@ -446,7 +450,6 @@ struct map_lookup { u64 type; int io_align; int io_width; - u32 stripe_len; int num_stripes; int sub_stripes; int verified_stripes; /* For mount time dev extent verification */ |