vfs: Add ioflag to VOP_DEALLOCATE(9)

[khng]

Summary

The addition of ioflag allows callers passing
IO_SYNC/IO_DATASYNC/IO_DIRECT down to the file system implementation.
The vop_stddeallocate fallback implementation is updated to pass the
ioflag to the file system implementation.
vn_deallocate(9) internally is also changed to pass ioflag to the
VOP_DEALLOCATE call.

Sponsored by: The FreeBSD Foundation

[kib]

sys/kern/vfs_vnops.c

3457

I suggest you to commit rename ioflg->ioflag as a preliminary change.

3473

Fix style: there should be spaces around '|'.

3554

!= 0

3555

!= 0

3563

() != 0

[khng]

Styles.

[kib]

sys/kern/vfs_vnops.c

3564

This ioflag calculation block was copied/pasted from vn_write(). Put it into a helper used in both places.

[khng]

• IO_SYNC and/or IO_DATASYNC ends up in a helper.
• Move IO_NODELOCKED | IO_RANGELOCKED style fix to D31505

[kib]

sys/kern/vfs_vnops.c

1143

Didn't previous version also handled O_DIRECT?

1145

I do not see why making the invocation of the helper more complicated. Move calculation of mp into it, as you see mp is cleared on the next line.

[khng]

• Let vn_fspacectl check O_DIRECT as well
• style

[khng]

Move mp = into the helper.

[khng]

get_sync_ioflag -> get_write_ioflag: Move IO_DIRECT checking into the helper.

[markj]

share/man/man9/vn_deallocate.9

70

Just copy the definition from VOP_DEALLOCATE?

79–80

sys/kern/vfs_vnops.c

1142–1146

Why not handle FNONBLOCK in the helper too?

[kib]

It is useful to extract get_write_ioflags() into separate commit. For instance, it can be merged to stable branches independently of other fspacectl changes.

sys/kern/vfs_vnops.c

930

() != 0

933

Same.

942

Same

[khng]

Dedicated commit for:

• vfs: Add get_write_ioflag handler to calculate ioflag

• Styles

[kib]

I asked for a commit that _only_ introduces get_write_ioflag() and replaces existing place(s) with it. Addition of flags anywhere is clearly a different change.

[khng]

• Separate get_write_ioflag commit (This currently calculates IO_DIRECT/IO_SYNC/IO_DATASYNC). I do not introduce IO_NDELAY calculation because it is clearly not going to be used by vn_fspacectl yet even it is harmless to just let it passthrough for now.