xref: /freebsd/share/man/man9/VOP_COPY_FILE_RANGE.9 (revision 6be3386466ab79a84b48429ae66244f21526d3df)
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26.\" $FreeBSD$
27.\"
28.Dd March 30, 2020
29.Dt VOP_COPY_FILE_RANGE 9
30.Os
31.Sh NAME
32.Nm VOP_COPY_FILE_RANGE
33.Nd copy a byte range from one file to another or within one file
34in a single file system
35.Sh SYNOPSIS
36.In sys/param.h
37.In sys/vnode.h
38.Ft int
39.Fo VOP_COPY_FILE_RANGE
40.Fa "struct vnode *invp"
41.Fa "off_t *inoff"
42.Fa "struct vnode *outvp"
43.Fa "off_t *outoff"
44.Fa "size_t *len"
45.Fa "unsigned int flags"
46.Fa "struct ucred *incred"
47.Fa "struct ucred *outcred"
48.Fa "struct thread *fsize_td"
49.Sh DESCRIPTION
50This entry point copies a byte range from one regular file to another
51or within one file in a single file system.
52.Fa invp
53and
54.Fa outvp
55can refer to the same file.
56For this case, the byte ranges defined by
57.Fa *inoff ,
58.Fa *outoff and
59.Fa *len
60will not overlap.
61.Pp
62The arguments are:
63.Bl -tag -width ioflag
64.It Fa invp
65The vnode of the input file.
66.It Fa inoff
67A pointer to the file offset for the input file.
68.It Fa outvp
69The vnode of the output file.
70.It Fa outoff
71A pointer to the file offset for the output file.
72.It Fa len
73A pointer to the byte count for the copy.
74.It Fa flags
75Flags, should be set to 0 for now.
76.It Fa incred
77The credentials used to read
78.Fa invp .
79.It Fa outcred
80The credentials used to write
81.Fa outvp .
82.It Fa fsize_td
83The thread pointer to be passed to vn_rlimit_fsize().
84This will be
85.Dv NULL
86for a server thread without limits, such as for the NFS
87server or
88.Dv curthread
89otherwise.
90.El
91.Pp
92On entry and on return, the
93.Fa inoff
94and
95.Fa outoff
96arguments point to the locations of the file offsets.
97These file offsets should be updated by the number of bytes copied.
98The
99.Fa len
100argument points to the location that stores the number of bytes
101to be copied.
102Upon a successful return
103.Fa len
104will be updated to the number of bytes actually copied.
105Normally, this will be the number of bytes requested to be copied,
106however a copy of fewer bytes than requested is permitted.
107This does not necessarily indicate that the copy reached EOF on the input file.
108However, if the value pointed to by the
109.Fa len
110argument is zero upon a successful return,
111it indicates that the offset pointed to by
112.Fa inoff
113is at or beyond EOF on the input file.
114.Sh LOCKS
115The vnode are unlocked on entry and must be unlocked on return.
116The byte ranges for both
117.Fa invp
118and
119.Fa outvp
120should be range locked when this call is done.
121.Sh RETURN VALUES
122Zero is returned on success, otherwise an error code is returned.
123.Sh ERRORS
124.Bl -tag -width Er
125.It Bq Er EFBIG
126If the copy exceeds the process's file size limit or the maximum file size
127for the file system
128.Fa invp
129and
130.Fa outvp
131reside on.
132.It Bq Er EINTR
133A signal interrupted the VOP call before it could be completed.
134.It Bq Er EIO
135An I/O error occurred while reading/writing the files.
136.It Bq Er EINTEGRITY
137Corrupted data was detected while reading/writing the files.
138.It Bq Er ENOSPC
139The file system is full.
140.El
141.Sh SEE ALSO
142.Xr vn_rdwr 9 ,
143.Xr vnode 9
144