fs: Add initial atomic write support info to statx

Extend statx system call to return additional info for atomic write support
support for a file.

Helper function generic_fill_statx_atomic_writes() can be used by FSes to
fill in the relevant statx fields. For now atomic_write_segments_max will
always be 1, otherwise some rules would need to be imposed on iovec length
and alignment, which we don't want now.

Signed-off-by: Prasad Singamsetty <prasad.singamsetty@oracle.com>
jpg: relocate bdev support to another patch
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20240620125359.2684798-5-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Prasad Singamsetty
2024-06-20 12:53:53 +00:00
committed by Jens Axboe
parent c34fc6f26a
commit 0f9ca80fa4
4 changed files with 50 additions and 2 deletions
+10 -2
View File
@@ -126,9 +126,15 @@ struct statx {
__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 */
__u64 stx_subvol; /* Subvolume identifier */
/* 0xa0 */
__u64 __spare3[11]; /* Spare space for future expansion */
__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 */
};
@@ -157,6 +163,7 @@ struct statx {
#define STATX_DIOALIGN 0x00002000U /* Want/got direct I/O alignment info */
#define STATX_MNT_ID_UNIQUE 0x00004000U /* Want/got extended stx_mount_id */
#define STATX_SUBVOL 0x00008000U /* Want/got stx_subvol */
#define STATX_WRITE_ATOMIC 0x00010000U /* Want/got atomic_write_* fields */
#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */
@@ -192,6 +199,7 @@ struct statx {
#define STATX_ATTR_MOUNT_ROOT 0x00002000 /* Root of a mount */
#define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */
#define STATX_ATTR_DAX 0x00200000 /* File is currently in DAX state */
#define STATX_ATTR_WRITE_ATOMIC 0x00400000 /* File supports atomic write operations */
#endif /* _UAPI_LINUX_STAT_H */