xref: /freebsd/share/man/man9/VOP_DEALLOCATE.9 (revision 1f88aa09417f1cfb3929fd37531b1ab51213c2d6)
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30.Dd May 11, 2021
31.Dt VOP_DEALLOCATE 9
32.Os
33.Sh NAME
34.Nm VOP_DEALLOCATE
35.Nd zero and/or deallocate storage from a file
36.Sh SYNOPSIS
37.In sys/param.h
38.In sys/vnode.h
39.Ft int
40.Fo VOP_DEALLOCATE
41.Fa "struct vnode *vp"
42.Fa "off_t *offset"
43.Fa "off_t *len"
44.Fa "int flags"
45.Fa "struct ucred *cred"
46.Fc
47.Sh DESCRIPTION
48This VOP call zeroes/deallocates storage for an offset range in a file.
49It is used to implement the
50.Xr fspacectl 2
51system call.
52.Pp
53Its arguments are:
54.Bl -tag -width offset
55.It Fa vp
56The vnode of the file.
57.It Fa offset
58The start of the range to deallocate storage in the file.
59.It Fa len
60The length of the range to deallocate storage in the file.
61.It Fa flags
62The flags of this call.
63This should be set to 0 for now.
64.It Fa cred
65The credentials of the caller.
66.El
67.Pp
68.Fa *offset
69and
70.Fa *len
71are updated to reflect the portion of the range that
72still needs to be zeroed/deallocated on return.
73Partial result is considered a successful operation.
74.Sh LOCKS
75The vnode should be locked on entry and will still be locked on exit.
76.Sh RETURN VALUES
77Zero is returned if the call is successful, otherwise an appropriate
78error code is returned.
79.Sh ERRORS
80.Bl -tag -width Er
81.It Bq Er EINVAL
82Invalid
83.Fa offset , len
84or
85.Fa flags
86parameters are passed into this VOP call.
87.It Bq Er ENODEV
88The vnode type is not supported by this VOP call.
89.It Bq Er ENOSPC
90The file system is full.
91.It Bq Er EPERM
92An append-only flag is set on the file, but the caller is attempting to
93zero before the current end of file.
94.El
95.Sh SEE ALSO
96.Xr vnode 9
97.Sh AUTHORS
98.Nm
99and this manual page was written by
100.An Ka Ho Ng Aq Mt khng@FreeBSD.org
101under sponsorship from the FreeBSD Foundation.
102