xref: /freebsd/share/man/man9/VOP_COPY_FILE_RANGE.9 (revision 716fd348e01c5f2ba125f878a634a753436c2994)
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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.Fc
50.Sh DESCRIPTION
51This entry point copies a byte range from one regular file to another
52or within one file in a single file system.
53.Fa invp
54and
55.Fa outvp
56can refer to the same file.
57For this case, the byte ranges defined by
58.Fa *inoff ,
59.Fa *outoff and
60.Fa *len
61will not overlap.
62.Pp
63The arguments are:
64.Bl -tag -width ioflag
65.It Fa invp
66The vnode of the input file.
67.It Fa inoff
68A pointer to the file offset for the input file.
69.It Fa outvp
70The vnode of the output file.
71.It Fa outoff
72A pointer to the file offset for the output file.
73.It Fa len
74A pointer to the byte count for the copy.
75.It Fa flags
76Flags, should be set to 0 for now.
77.It Fa incred
78The credentials used to read
79.Fa invp .
80.It Fa outcred
81The credentials used to write
82.Fa outvp .
83.It Fa fsize_td
84The thread pointer to be passed to vn_rlimit_fsize().
85This will be
86.Dv NULL
87for a server thread without limits, such as for the NFS
88server or
89.Dv curthread
90otherwise.
91.El
92.Pp
93On entry and on return, the
94.Fa inoff
95and
96.Fa outoff
97arguments point to the locations of the file offsets.
98These file offsets should be updated by the number of bytes copied.
99The
100.Fa len
101argument points to the location that stores the number of bytes
102to be copied.
103Upon a successful return
104.Fa len
105will be updated to the number of bytes actually copied.
106Normally, this will be the number of bytes requested to be copied,
107however a copy of fewer bytes than requested is permitted.
108This does not necessarily indicate that the copy reached EOF on the input file.
109However, if the value pointed to by the
110.Fa len
111argument is zero upon a successful return,
112it indicates that the offset pointed to by
113.Fa inoff
114is at or beyond EOF on the input file.
115.Sh LOCKS
116The vnode are unlocked on entry and must be unlocked on return.
117The byte ranges for both
118.Fa invp
119and
120.Fa outvp
121should be range locked when this call is done.
122.Sh RETURN VALUES
123Zero is returned on success, otherwise an error code is returned.
124.Sh ERRORS
125.Bl -tag -width Er
126.It Bq Er EFBIG
127If the copy exceeds the process's file size limit or the maximum file size
128for the file system
129.Fa invp
130and
131.Fa outvp
132reside on.
133.It Bq Er EINTR
134A signal interrupted the VOP call before it could be completed.
135.It Bq Er EIO
136An I/O error occurred while reading/writing the files.
137.It Bq Er EINTEGRITY
138Corrupted data was detected while reading/writing the files.
139.It Bq Er ENOSPC
140The file system is full.
141.El
142.Sh SEE ALSO
143.Xr vn_rdwr 9 ,
144.Xr vnode 9
145