On 16.10.2017 11:22, Qu Wenruo wrote:
> Since commit c11e36a29e84 ("Btrfs-progs: Do not force mixed block group
> creation unless '-M' option is specified"), mkfs no longer use mixed
> block group unless specified manually.
>
> This breaks the minimal device size calculation, which only considered
> mixed block group use case.
>
> This patch enhances minimal device size calculation for mkfs, by using
> different minimal stripe length (calculated from code) for different
> profiles, and use them to calculate minimal device size.
>
> Reported-by: Wesley Aptekar-Cassels <W.Aptekar@xxxxxxxxx>
> Fixes: c11e36a29e84 ("Btrfs-progs: Do not force mixed block group creation unless '-M' option is specified")
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
> Reviewed-by: Lu Fengqi <lufq.fnst@xxxxxxxxxxxxxx>
> ---
> v2:
> Rebased on the cleanup patch.
> ---
> mkfs/common.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++------
> mkfs/common.h | 4 ++--
> mkfs/main.c | 3 ++-
> 3 files changed, 65 insertions(+), 10 deletions(-)
>
> diff --git a/mkfs/common.c b/mkfs/common.c
> index 71318b10fa51..2c400f44dbf3 100644
> --- a/mkfs/common.c
> +++ b/mkfs/common.c
> @@ -438,12 +438,6 @@ out:
> return ret;
> }
>
> -u64 btrfs_min_dev_size(u32 nodesize)
> -{
> - return 2 * (BTRFS_MKFS_SYSTEM_GROUP_SIZE +
> - btrfs_min_global_blk_rsv_size(nodesize));
> -}
> -
> /*
> * Btrfs minimum size calculation is complicated, it should include at least:
> * 1. system group size
> @@ -454,11 +448,71 @@ u64 btrfs_min_dev_size(u32 nodesize)
> * To avoid the overkill calculation, (system group + global block rsv) * 2
> * for *EACH* device should be good enough.
> */
> -u64 btrfs_min_global_blk_rsv_size(u32 nodesize)
> +static u64 btrfs_min_global_blk_rsv_size(u32 nodesize)
> {
> return (u64)nodesize << 10;
> }
>
> +u64 btrfs_min_dev_size(u32 nodesize, int mixed, u64 meta_profile,
> + u64 data_profile)
> +{
> + u64 reserved = 0;
> + u64 meta_size;
> + u64 data_size;
> +
> + if (mixed)
> + return 2 * (BTRFS_MKFS_SYSTEM_GROUP_SIZE +
> + btrfs_min_global_blk_rsv_size(nodesize));
Make mixed a boolean if it's only ever used as such .
> +
> + /*
> + * minimal size calculation is complex due to several factors:
> + * 1) Temporary chunk resue
^ reuse?
> + * If specified chunk profile is SINGLE, we can resue
> + * temporary chunks, no need to alloc new chunks.
> + *
> + * 2) Different minimal chunk size for different profile
> + * For initial sys chunk, chunk size is fixed to 4M.
> + * For single profile, minimal chunk size is 8M for all.
> + * For other profiles, minimal chunk and stripe size
> + * differs from 8M to 64M.
^ range
> + *
> + * To calculate it a little easier, here we assume we don't
> + * reuse any temporary chunk, and calculate the size all
> + * by ourselves.
> + *
> + * Temporary chunks sizes are always fixed:
> + * One initial sys chunk, one SINGLE meta, and one SINGLE data.
> + * The latter two are all 8M, accroding to @calc_size of
> + * btrfs_alloc_chunk().
> + */
> + reserved += BTRFS_MKFS_SYSTEM_GROUP_SIZE + SZ_8M * 2;
> +
> + /*
> + * For real chunks, we need to refer different sizes:
> + * For SINGLE, it's still fixed to 8M (@calc_size).
> + * For other profiles, refer to max(@min_stripe_size, @calc_size).
> + *
> + * And use the stripe size to calculate its physical used space.
> + */
> + if (meta_profile & BTRFS_BLOCK_GROUP_PROFILE_MASK)
> + meta_size = SZ_8M + SZ_32M;
> + else
> + meta_size = SZ_8M + SZ_8M;
> + /* Only metadata put 2 stripes into one disk */
> + if (meta_profile & BTRFS_BLOCK_GROUP_DUP)
> + meta_size *= 2;
> + reserved += meta_size;
> +
> + if (data_profile & BTRFS_BLOCK_GROUP_PROFILE_MASK)
> + data_size = SZ_64M;
> + else
> + data_size = SZ_8M;
> + if (data_profile & BTRFS_BLOCK_GROUP_DUP)
> + data_size *= 2;
> + reserved += data_size;
> + return reserved;
> +}
> +
> #define isoctal(c) (((c) & ~7) == '0')
>
> static inline void translate(char *f, char *t)
> diff --git a/mkfs/common.h b/mkfs/common.h
> index 3757e9e7fd0a..e9e3b3eb43a6 100644
> --- a/mkfs/common.h
> +++ b/mkfs/common.h
> @@ -66,8 +66,8 @@ struct btrfs_mkfs_config {
> };
>
> int make_btrfs(int fd, struct btrfs_mkfs_config *cfg);
> -u64 btrfs_min_dev_size(u32 nodesize);
> -u64 btrfs_min_global_blk_rsv_size(u32 nodesize);
> +u64 btrfs_min_dev_size(u32 nodesize, int mixed, u64 meta_profile,
> + u64 data_profile);
> int test_minimum_size(const char *file, u64 min_dev_size);
> int is_vol_small(const char *file);
> int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
> diff --git a/mkfs/main.c b/mkfs/main.c
> index 97c2d133f3c5..80e6089c37a1 100644
> --- a/mkfs/main.c
> +++ b/mkfs/main.c
> @@ -1647,7 +1647,8 @@ int main(int argc, char **argv)
> goto error;
> }
>
> - min_dev_size = btrfs_min_dev_size(nodesize);
> + min_dev_size = btrfs_min_dev_size(nodesize, mixed, metadata_profile,
> + data_profile);
> /* Check device/block_count after the nodesize is determined */
> if (block_count && block_count < min_dev_size) {
> error("size %llu is too small to make a usable filesystem",
>
--
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