On Mon, Nov 18, 2024 at 03:52:55PM -0800, Catherine Hoang wrote:
> Add support for the new atomic_write_unit_min, atomic_write_unit_max, and
> atomic_write_segments_max fields in statx for xfs_io. In order to support builds
> against old kernel headers, define our own internal statx structs. If the
> system's struct statx does not have the required atomic write fields, override
> the struct definitions with the internal definitions in statx.h.
>
> Signed-off-by: Catherine Hoang <catherine.hoang@xxxxxxxxxx>
> ---
> configure.ac | 1 +
> include/builddefs.in | 4 ++++
> io/stat.c | 7 +++++++
> io/statx.h | 23 ++++++++++++++++++++++-
> m4/package_libcdev.m4 | 20 ++++++++++++++++++++
> 5 files changed, 54 insertions(+), 1 deletion(-)
>
> diff --git a/configure.ac b/configure.ac
> index 33b01399..0b1ef3c3 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -146,6 +146,7 @@ AC_HAVE_COPY_FILE_RANGE
> AC_NEED_INTERNAL_FSXATTR
> AC_NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG
> AC_NEED_INTERNAL_FSCRYPT_POLICY_V2
> +AC_NEED_INTERNAL_STATX
> AC_HAVE_GETFSMAP
> AC_HAVE_MAP_SYNC
> AC_HAVE_DEVMAPPER
> diff --git a/include/builddefs.in b/include/builddefs.in
> index 1647d2cd..cbc9ab0c 100644
> --- a/include/builddefs.in
> +++ b/include/builddefs.in
> @@ -96,6 +96,7 @@ HAVE_COPY_FILE_RANGE = @have_copy_file_range@
> NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@
> NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG = @need_internal_fscrypt_add_key_arg@
> NEED_INTERNAL_FSCRYPT_POLICY_V2 = @need_internal_fscrypt_policy_v2@
> +NEED_INTERNAL_STATX = @need_internal_statx@
> HAVE_GETFSMAP = @have_getfsmap@
> HAVE_MAP_SYNC = @have_map_sync@
> HAVE_DEVMAPPER = @have_devmapper@
> @@ -130,6 +131,9 @@ endif
> ifeq ($(NEED_INTERNAL_FSCRYPT_POLICY_V2),yes)
> PCFLAGS+= -DOVERRIDE_SYSTEM_FSCRYPT_POLICY_V2
> endif
> +ifeq ($(NEED_INTERNAL_STATX),yes)
> +PCFLAGS+= -DOVERRIDE_SYSTEM_STATX
> +endif
> ifeq ($(HAVE_GETFSMAP),yes)
> PCFLAGS+= -DHAVE_GETFSMAP
> endif
> diff --git a/io/stat.c b/io/stat.c
> index 0f5618f6..7d1c1c93 100644
> --- a/io/stat.c
> +++ b/io/stat.c
> @@ -6,6 +6,10 @@
> * Portions of statx support written by David Howells (dhowells@xxxxxxxxxx)
> */
>
> +#ifdef OVERRIDE_SYSTEM_STATX
> +#define statx sys_statx
> +#endif
> +
> #include "command.h"
> #include "input.h"
> #include "init.h"
> @@ -347,6 +351,9 @@ dump_raw_statx(struct statx *stx)
> printf("stat.rdev_minor = %u\n", stx->stx_rdev_minor);
> printf("stat.dev_major = %u\n", stx->stx_dev_major);
> printf("stat.dev_minor = %u\n", stx->stx_dev_minor);
> + printf("stat.atomic_write_unit_min = %lld\n", (long long)stx->stx_atomic_write_unit_min);
> + printf("stat.atomic_write_unit_max = %lld\n", (long long)stx->stx_atomic_write_unit_max);
> + printf("stat.atomic_write_segments_max = %lld\n", (long long)stx->stx_atomic_write_segments_max);
> return 0;
> }
>
> diff --git a/io/statx.h b/io/statx.h
> index c6625ac4..d151f732 100644
> --- a/io/statx.h
> +++ b/io/statx.h
> @@ -61,6 +61,7 @@ struct statx_timestamp {
> __s32 tv_nsec;
> __s32 __reserved;
> };
> +#endif
>
> /*
> * Structures for the extended file attribute retrieval system call
> @@ -99,6 +100,8 @@ struct statx_timestamp {
> * will have values installed for compatibility purposes so that stat() and
> * co. can be emulated in userspace.
> */
> +#if !defined STATX_TYPE || defined OVERRIDE_SYSTEM_STATX
Is there any place where STATX_TYPE is not defined but
OVERRIDE_SYSTEM_STATX will *also* not be defined?
I think the m4 macro you added sets need_internal_statx=yes for old
systems where there's no STATX_TYPE, because there won't be a struct
statx, let alone atomic_write_* fields in it, right?
--D
> +#undef statx
> struct statx {
> /* 0x00 */
> __u32 stx_mask; /* What results were written [uncond] */
> @@ -126,10 +129,23 @@ struct statx {
> __u32 stx_dev_major; /* ID of device containing file [uncond] */
> __u32 stx_dev_minor;
> /* 0x90 */
> - __u64 __spare2[14]; /* Spare space for future expansion */
> + __u64 stx_mnt_id;
> + __u32 stx_dio_mem_align; /* Memory buffer alignment for direct I/O */
> + __u32 stx_dio_offset_align; /* File offset alignment for direct I/O */
> + /* 0xa0 */
> + __u64 stx_subvol; /* Subvolume identifier */
> + __u32 stx_atomic_write_unit_min; /* Min atomic write unit in bytes */
> + __u32 stx_atomic_write_unit_max; /* Max atomic write unit in bytes */
> + /* 0xb0 */
> + __u32 stx_atomic_write_segments_max; /* Max atomic write segment count */
> + __u32 __spare1[1];
> + /* 0xb8 */
> + __u64 __spare3[9]; /* Spare space for future expansion */
> /* 0x100 */
> };
> +#endif
>
> +#ifndef STATX_TYPE
> /*
> * Flags to be stx_mask
> *
> @@ -174,4 +190,9 @@ struct statx {
> #define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */
>
> #endif /* STATX_TYPE */
> +
> +#ifndef STATX_WRITE_ATOMIC
> +#define STATX_WRITE_ATOMIC 0x00010000U /* Want/got atomic_write_* fields */
> +#endif
> +
> #endif /* XFS_IO_STATX_H */
> diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
> index 6de8b33e..bc8a49a9 100644
> --- a/m4/package_libcdev.m4
> +++ b/m4/package_libcdev.m4
> @@ -98,6 +98,26 @@ AC_DEFUN([AC_NEED_INTERNAL_FSCRYPT_POLICY_V2],
> AC_SUBST(need_internal_fscrypt_policy_v2)
> ])
>
> +#
> +# Check if we need to override the system struct statx with
> +# the internal definition. This /only/ happens if the system
> +# actually defines struct statx /and/ the system definition
> +# is missing certain fields.
> +#
> +AC_DEFUN([AC_NEED_INTERNAL_STATX],
> + [ AC_CHECK_TYPE(struct statx,
> + [
> + AC_CHECK_MEMBER(struct statx.stx_atomic_write_unit_min,
> + ,
> + need_internal_statx=yes,
> + [#include <linux/stat.h>]
> + )
> + ],,
> + [#include <linux/stat.h>]
> + )
> + AC_SUBST(need_internal_statx)
> + ])
> +
> #
> # Check if we have a FS_IOC_GETFSMAP ioctl (Linux)
> #
> --
> 2.34.1
>
>
