vfs_getnewfsid.9 (ffc0b97fd087519392b19a9d43056d7099b831eb) vfs_getnewfsid.9 (1f620c2ead117e9b4f698560053721d05a6637a3)
1.\"
2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice(s), this list of conditions and the following disclaimer as

--- 17 unchanged lines hidden (view full) ---

26.\"
27.\" $FreeBSD$
28.\"
29.Dd November 21, 2001
30.Dt VFS_GETNEWFSID 9
31.Os
32.Sh NAME
33.Nm vfs_getnewfsid
1.\"
2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice(s), this list of conditions and the following disclaimer as

--- 17 unchanged lines hidden (view full) ---

26.\"
27.\" $FreeBSD$
28.\"
29.Dd November 21, 2001
30.Dt VFS_GETNEWFSID 9
31.Os
32.Sh NAME
33.Nm vfs_getnewfsid
34.Nd "allocate a new fsid"
34.Nd "allocate a new filesystem identifier"
35.Sh SYNOPSIS
36.In sys/param.h
37.In sys/mount.h
38.Ft void
39.Fn vfs_getnewfsid "struct mount *mp"
40.Sh DESCRIPTION
41The
42.Fn vfs_getnewfsid
43function allocates a new filesystem identifier for the mount point given.
44Filesystems typically call
45.Fn vfs_getnewfsid
35.Sh SYNOPSIS
36.In sys/param.h
37.In sys/mount.h
38.Ft void
39.Fn vfs_getnewfsid "struct mount *mp"
40.Sh DESCRIPTION
41The
42.Fn vfs_getnewfsid
43function allocates a new filesystem identifier for the mount point given.
44Filesystems typically call
45.Fn vfs_getnewfsid
46in their mount routine in order to acquire a unique id within the system
46in their mount routine in order to acquire a unique ID within the system
47which can later be used to uniquely identify the filesystem via calls such as
47which can later be used to uniquely identify the filesystem via calls such as
48.Fn vfs_getvfs .
48.Xr vfs_getvfs 9 .
49.Pp
49.Pp
50The actual fsid is made up of two 32 bit integers, that are stored in the statfs
50The actual
51.Vt fsid
52is made up of two 32 bit integers, that are stored in the
53.Vt statfs
51structure of
52.Fa mp .
54structure of
55.Fa mp .
53The first integer is unique in the set of mounted filesystems, while the second holds
54the filesystem type.
56The first integer is unique in the set of mounted filesystems,
57while the second holds the filesystem type.
55.Bd -literal
58.Bd -literal
56 typedef struct fsid {
57 int32_t val[2];
58 } fsid_t;
59typedef struct fsid {
60 int32_t val[2];
61} fsid_t;
59.Ed
60.Sh PSEUDOCODE
61.Bd -literal
62.Ed
63.Sh PSEUDOCODE
64.Bd -literal
62 xxx_mount(struct mount *mp, char *path, caddr_t data, struct nameidata *ndp, struct thread *td)
63 {
64 ...
65 vfs_getnewfsid(mp);
66 ...
67 }
65xxx_mount(struct mount *mp, char *path, caddr_t data,
66 struct nameidata *ndp, struct thread *td)
67{
68 ...
69 vfs_getnewfsid(mp);
70 ...
71}
68.Ed
69.Sh SEE ALSO
70.Xr vfs_getvfs 9
71.Sh AUTHORS
72This man page was written by
73.An Chad David Aq davidc@acns.ab.ca .
72.Ed
73.Sh SEE ALSO
74.Xr vfs_getvfs 9
75.Sh AUTHORS
76This man page was written by
77.An Chad David Aq davidc@acns.ab.ca .