| Message ID | 20250108085900.GA27227@lst.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | statx.2: document STATX_DIO_READ_ALIGN | expand |
On Wed, Jan 08, 2025 at 09:59:00AM +0100, Christoph Hellwig wrote: > Document the new STATX_DIO_READ_ALIGN flag and the new > stx_dio_read_offset_align field guarded by it. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > man/man2/statx.2 | 26 +++++++++++++++++++++++++- > 1 file changed, 25 insertions(+), 1 deletion(-) > > diff --git a/man/man2/statx.2 b/man/man2/statx.2 > index c5b5a28ec2f1..8ef6a1cfb1c0 100644 > --- a/man/man2/statx.2 > +++ b/man/man2/statx.2 > @@ -76,6 +76,9 @@ struct statx { > __u32 stx_atomic_write_unit_min; > __u32 stx_atomic_write_unit_max; > __u32 stx_atomic_write_segments_max; > + > + /* File offset alignment for direct I/O reads */ > + __u32 stx_dio_read_offset_align; > }; > .EE > .in > @@ -261,7 +264,7 @@ STATX_BTIME Want stx_btime > STATX_ALL The same as STATX_BASIC_STATS | STATX_BTIME. > It is deprecated and should not be used. > STATX_MNT_ID Want stx_mnt_id (since Linux 5.8) > -STATX_DIOALIGN Want stx_dio_mem_align and stx_dio_offset_align > +STATX_DIOALIGN Want stx_dio_mem_align and stx_dio_offset_align. > (since Linux 6.1; support varies by filesystem) > STATX_MNT_ID_UNIQUE Want unique stx_mnt_id (since Linux 6.8) > STATX_SUBVOL Want stx_subvol > @@ -270,6 +273,8 @@ STATX_WRITE_ATOMIC Want stx_atomic_write_unit_min, > stx_atomic_write_unit_max, > and stx_atomic_write_segments_max. > (since Linux 6.11; support varies by filesystem) > +STATX_DIO_READ_ALIGN Want stx_dio_read_offset_align. > + (since Linux 6.14; support varies by filesystem) > .TE > .in > .P > @@ -467,6 +472,25 @@ This will only be nonzero if > .I stx_dio_mem_align > is nonzero, and vice versa. > .TP > +.I stx_dio_read_offset_align > +The alignment (in bytes) required for file offsets and I/O segment lengths for > +direct I/O reads > +.RB ( O_DIRECT ) > +on this file. > +If zero the limit in nit: add a comma here (really a dependent clause) to make it clearer that 'zero' isn't being used as a verb here: "If zero, the limit in..." > +.I stx_dio_offset_align > +applies for reads as well. > +If non-zero this value must be smaller than Same here. "If non-zero, this value..." With that fixed, Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> --D > +.I stx_dio_offset_align > +which must be provided by the file system. > +The memory alignment in > +.I stx_dio_mem_align > +is not affected by this value. > +.IP > +.B STATX_DIO_READ_ALIGN > +.RI ( stx_dio_offset_align ) > +is supported by xfs on regular files since Linux 6.14. > +.TP > .I stx_subvol > Subvolume number of the current file. > .IP > -- > 2.45.2 > >
diff --git a/man/man2/statx.2 b/man/man2/statx.2 index c5b5a28ec2f1..8ef6a1cfb1c0 100644 --- a/man/man2/statx.2 +++ b/man/man2/statx.2 @@ -76,6 +76,9 @@ struct statx { __u32 stx_atomic_write_unit_min; __u32 stx_atomic_write_unit_max; __u32 stx_atomic_write_segments_max; + + /* File offset alignment for direct I/O reads */ + __u32 stx_dio_read_offset_align; }; .EE .in @@ -261,7 +264,7 @@ STATX_BTIME Want stx_btime STATX_ALL The same as STATX_BASIC_STATS | STATX_BTIME. It is deprecated and should not be used. STATX_MNT_ID Want stx_mnt_id (since Linux 5.8) -STATX_DIOALIGN Want stx_dio_mem_align and stx_dio_offset_align +STATX_DIOALIGN Want stx_dio_mem_align and stx_dio_offset_align. (since Linux 6.1; support varies by filesystem) STATX_MNT_ID_UNIQUE Want unique stx_mnt_id (since Linux 6.8) STATX_SUBVOL Want stx_subvol @@ -270,6 +273,8 @@ STATX_WRITE_ATOMIC Want stx_atomic_write_unit_min, stx_atomic_write_unit_max, and stx_atomic_write_segments_max. (since Linux 6.11; support varies by filesystem) +STATX_DIO_READ_ALIGN Want stx_dio_read_offset_align. + (since Linux 6.14; support varies by filesystem) .TE .in .P @@ -467,6 +472,25 @@ This will only be nonzero if .I stx_dio_mem_align is nonzero, and vice versa. .TP +.I stx_dio_read_offset_align +The alignment (in bytes) required for file offsets and I/O segment lengths for +direct I/O reads +.RB ( O_DIRECT ) +on this file. +If zero the limit in +.I stx_dio_offset_align +applies for reads as well. +If non-zero this value must be smaller than +.I stx_dio_offset_align +which must be provided by the file system. +The memory alignment in +.I stx_dio_mem_align +is not affected by this value. +.IP +.B STATX_DIO_READ_ALIGN +.RI ( stx_dio_offset_align ) +is supported by xfs on regular files since Linux 6.14. +.TP .I stx_subvol Subvolume number of the current file. .IP
Document the new STATX_DIO_READ_ALIGN flag and the new stx_dio_read_offset_align field guarded by it. Signed-off-by: Christoph Hellwig <hch@lst.de> --- man/man2/statx.2 | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-)