xref: /freebsd/share/man/man9/VOP_ALLOCATE.9 (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
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28.Dd November 8, 2021
29.Dt VOP_ALLOCATE 9
30.Os
31.Sh NAME
32.Nm VOP_ALLOCATE
33.Nd allocate storage for a file
34.Sh SYNOPSIS
35.In sys/param.h
36.In sys/vnode.h
37.Ft int
38.Fo VOP_ALLOCATE
39.Fa "struct vnode *vp"
40.Fa "off_t *offset"
41.Fa "off_t *len"
42.Fa "int ioflag"
43.Fa "struct ucred *cred"
44.Fc
45.Sh DESCRIPTION
46This call allocates storage for a range of offsets in a file.
47It is used to implement the
48.Xr posix_fallocate
49system call.
50.Pp
51Its arguments are:
52.Bl -tag -width offset
53.It Fa vp
54The vnode of the file.
55.It Fa offset
56The start of the range to allocate storage for in the file.
57.It Fa len
58The length of the range to allocate storage for in the file.
59.It Fa ioflag
60Directives and hints to be given to the file system.
61.It Fa cred
62The credentials of the caller.
63.El
64.Pp
65The
66.Fa offset
67and
68.Fa len
69arguments are updated to reflect the portion of the range that
70still needs to be allocated on return.
71A partial allocation is considered a successful operation.
72The file's contents are not changed.
73.Sh LOCKS
74The file should be exclusively locked on entry and will still be locked on exit.
75.Sh RETURN VALUES
76Zero is returned if the call is successful, otherwise an appropriate
77error code is returned.
78.Sh ERRORS
79.Bl -tag -width Er
80.It Bq Er EFBIG
81An attempt was made to write a file that exceeds the process's file size
82limit or the maximum file size.
83.It Bq Er ENOSPC
84The file system is full.
85.It Bq Er EPERM
86An append-only flag is set on the file, but the caller is attempting to
87write before the current end of file.
88.El
89.Sh SEE ALSO
90.Xr vnode 9 ,
91.Xr VOP_READ 9 ,
92.Xr VOP_WRITE 9
93