| Message ID | 20211021014020.482242-2-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs-progs: cleanup related to btrfs super block | expand |
On Thu, Oct 21, 2021 at 09:40:18AM +0800, Qu Wenruo wrote: > Just like kernel change, pad struct btrfs_super_block to 4096 bytes. > > Signed-off-by: Qu Wenruo <wqu@suse.com> > --- > kernel-shared/ctree.h | 7 +++++++ > kernel-shared/disk-io.h | 3 --- > 2 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h > index 563ea50b3587..6451690ce4fa 100644 > --- a/kernel-shared/ctree.h > +++ b/kernel-shared/ctree.h > @@ -406,6 +406,9 @@ struct btrfs_root_backup { > u8 unused_8[10]; > } __attribute__ ((__packed__)); > > +#define BTRFS_SUPER_INFO_OFFSET SZ_64K > +#define BTRFS_SUPER_INFO_SIZE 4096 > + > /* > * the super block basically lists the main trees of the FS > * it currently lacks any block count etc etc > @@ -456,8 +459,12 @@ struct btrfs_super_block { > __le64 reserved[28]; > u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE]; > struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS]; > + /* Padded to 4096 bytes */ > + u8 padding[565]; > } __attribute__ ((__packed__)); > > +static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE); Using static_assert breaks build on musl (you can verify that by running ci/ci-build-musl if you have docker installed and set up). There already is macro BUILD_ASSERT used in ioctl.h, eventually we can copy the static_assert from kernel or use _Static_assert directly.
On 2021/10/21 20:40, David Sterba wrote: > On Thu, Oct 21, 2021 at 09:40:18AM +0800, Qu Wenruo wrote: >> Just like kernel change, pad struct btrfs_super_block to 4096 bytes. >> >> Signed-off-by: Qu Wenruo <wqu@suse.com> >> --- >> kernel-shared/ctree.h | 7 +++++++ >> kernel-shared/disk-io.h | 3 --- >> 2 files changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h >> index 563ea50b3587..6451690ce4fa 100644 >> --- a/kernel-shared/ctree.h >> +++ b/kernel-shared/ctree.h >> @@ -406,6 +406,9 @@ struct btrfs_root_backup { >> u8 unused_8[10]; >> } __attribute__ ((__packed__)); >> >> +#define BTRFS_SUPER_INFO_OFFSET SZ_64K >> +#define BTRFS_SUPER_INFO_SIZE 4096 >> + >> /* >> * the super block basically lists the main trees of the FS >> * it currently lacks any block count etc etc >> @@ -456,8 +459,12 @@ struct btrfs_super_block { >> __le64 reserved[28]; >> u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE]; >> struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS]; >> + /* Padded to 4096 bytes */ >> + u8 padding[565]; >> } __attribute__ ((__packed__)); >> >> +static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE); > > Using static_assert breaks build on musl (you can verify that by running > ci/ci-build-musl if you have docker installed and set up). > > There already is macro BUILD_ASSERT used in ioctl.h, eventually we can > copy the static_assert from kernel or use _Static_assert directly. > Mind to fix that on your side? As I don't yet have any building environment for musl to verify the failure or fix. Thanks, Qu
diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h index 563ea50b3587..6451690ce4fa 100644 --- a/kernel-shared/ctree.h +++ b/kernel-shared/ctree.h @@ -406,6 +406,9 @@ struct btrfs_root_backup { u8 unused_8[10]; } __attribute__ ((__packed__)); +#define BTRFS_SUPER_INFO_OFFSET SZ_64K +#define BTRFS_SUPER_INFO_SIZE 4096 + /* * the super block basically lists the main trees of the FS * it currently lacks any block count etc etc @@ -456,8 +459,12 @@ struct btrfs_super_block { __le64 reserved[28]; u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE]; struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS]; + /* Padded to 4096 bytes */ + u8 padding[565]; } __attribute__ ((__packed__)); +static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE); + /* * Compat flags that we support. If any incompat flags are set other than the * ones specified below then we will fail to mount diff --git a/kernel-shared/disk-io.h b/kernel-shared/disk-io.h index e113d842c906..823e5af37e75 100644 --- a/kernel-shared/disk-io.h +++ b/kernel-shared/disk-io.h @@ -23,9 +23,6 @@ #include "kernel-shared/ctree.h" #include "kernel-lib/sizes.h" -#define BTRFS_SUPER_INFO_OFFSET SZ_64K -#define BTRFS_SUPER_INFO_SIZE 4096 - #define BTRFS_SUPER_MIRROR_MAX 3 #define BTRFS_SUPER_MIRROR_SHIFT 12
Just like kernel change, pad struct btrfs_super_block to 4096 bytes. Signed-off-by: Qu Wenruo <wqu@suse.com> --- kernel-shared/ctree.h | 7 +++++++ kernel-shared/disk-io.h | 3 --- 2 files changed, 7 insertions(+), 3 deletions(-)