xref: /freebsd/share/man/man9/VOP_DEALLOCATE.9 (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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30.Dd August 25, 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 "int ioflag"
46.Fa "struct ucred *cred"
47.Fc
48.Sh DESCRIPTION
49This VOP call zeroes/deallocates storage for an offset range in a file.
50It is used to implement the
51.Xr fspacectl 2
52system call.
53.Pp
54Its arguments are:
55.Bl -tag -width offset
56.It Fa vp
57The vnode of the file.
58.It Fa offset
59The start of the range to deallocate storage in the file.
60.It Fa len
61The length of the range to deallocate storage in the file.
62.It Fa flags
63The flags of this call.
64This should be set to 0 for now.
65.It Fa ioflag
66Directives and hints to be given to the file system.
67.It Fa cred
68The credentials of the caller.
69.El
70.Pp
71.Fa *offset
72and
73.Fa *len
74are updated to reflect the portion of the range that
75still needs to be zeroed/deallocated on return.
76Partial result is considered a successful operation.
77For a non-partial successful completion,
78.Fa *len
79is updated to be the value 0, and
80.Fa *offset
81is incremented by the number of bytes zeroed before the end-of-file.
82.Sh LOCKS
83The vnode should be locked on entry and will still be locked on exit.
84.Sh RETURN VALUES
85Zero is returned if the call is successful, otherwise an appropriate
86error code is returned.
87.Sh ERRORS
88.Bl -tag -width Er
89.It Bq Er EINVAL
90Invalid
91.Fa offset , len
92or
93.Fa flags
94parameters are passed into this VOP call.
95.It Bq Er ENODEV
96The vnode type is not supported by this VOP call.
97.It Bq Er ENOSPC
98The file system is full.
99.It Bq Er EPERM
100An append-only flag is set on the file, but the caller is attempting to
101zero before the current end of file.
102.El
103.Sh SEE ALSO
104.Xr vnode 9
105.Sh AUTHORS
106.Nm
107and this manual page was written by
108.An Ka Ho Ng Aq Mt khng@FreeBSD.org
109under sponsorship from the FreeBSD Foundation.
110