The ioctl definitions for XFS_IOC_SWAPEXT, XFS_IOC_FSBULKSTAT and XFS_IOC_FSBULKSTAT_SINGLE are part of libxfs and based on time_t.
The definition for time_t differs between current kernels and coming 32-bit libc variants that define it as 64-bit. For most ioctls, that means the kernel has to be able to handle two different command codes based on the different structure sizes.
The same solution could be applied for XFS_IOC_SWAPEXT, but it would not work for XFS_IOC_FSBULKSTAT and XFS_IOC_FSBULKSTAT_SINGLE because the structure with the time_t is passed through an indirect pointer, and the command number itself is based on struct xfs_fsop_bulkreq, which does not differ based on time_t.
This means any solution that can be applied requires a change of the ABI definition in the xfs_fs.h header file, as well as doing the same change in any user application that contains a copy of this header.
The usual solution would be to define a replacement structure and use conditional compilation for the ioctl command codes to use one or the other, such as
#define XFS_IOC_FSBULKSTAT_OLD _IOWR('X', 101, struct xfs_fsop_bulkreq) #define XFS_IOC_FSBULKSTAT_NEW _IOWR('X', 129, struct xfs_fsop_bulkreq) #define XFS_IOC_FSBULKSTAT ((sizeof(time_t) == sizeof(__kernel_long_t)) ? \ XFS_IOC_FSBULKSTAT_OLD : XFS_IOC_FSBULKSTAT_NEW)
After this, the kernel would be able to implement both XFS_IOC_FSBULKSTAT_OLD and XFS_IOC_FSBULKSTAT_NEW handlers on 32-bit architectures with the correct ABI for either definition of time_t.
However, as long as two observations are true, a much simpler solution can be used:
1. xfsprogs is the only user space project that has a copy of this header 2. xfsprogs already has a replacement for all three affected ioctl commands, based on the xfs_bulkstat structure to pass 64-bit timestamps regardless of the architecture
Based on those assumptions, changing xfs_bstime to use __kernel_long_t instead of time_t in both the kernel and in xfsprogs preserves the current ABI for any libc definition of time_t and solves the problem of passing 64-bit timestamps to 32-bit user space.
If either of the two assumptions is invalid, more discussion is needed for coming up with a way to fix as much of the affected user space code as possible.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- fs/xfs/libxfs/xfs_fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index e9371a8e0e26..4c4330f6e653 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -324,7 +324,7 @@ typedef struct xfs_growfs_rt { * Structures returned from ioctl XFS_IOC_FSBULKSTAT & XFS_IOC_FSBULKSTAT_SINGLE */ typedef struct xfs_bstime { - time_t tv_sec; /* seconds */ + __kernel_long_t tv_sec; /* seconds */ __s32 tv_nsec; /* and nanoseconds */ } xfs_bstime_t;