xref: /freebsd/share/man/man9/VOP_COPY_FILE_RANGE.9 (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
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26.Dd March 30, 2020
27.Dt VOP_COPY_FILE_RANGE 9
28.Os
29.Sh NAME
30.Nm VOP_COPY_FILE_RANGE
31.Nd copy a byte range within a file or from one file to another in a single
32file system or between multiple file systems
33.Sh SYNOPSIS
34.In sys/param.h
35.In sys/vnode.h
36.Ft int
37.Fo VOP_COPY_FILE_RANGE
38.Fa "struct vnode *invp"
39.Fa "off_t *inoff"
40.Fa "struct vnode *outvp"
41.Fa "off_t *outoff"
42.Fa "size_t *len"
43.Fa "unsigned int flags"
44.Fa "struct ucred *incred"
45.Fa "struct ucred *outcred"
46.Fa "struct thread *fsize_td"
47.Fc
48.Sh DESCRIPTION
49This entry point copies a byte range from one regular file to another
50or within one file in a single file system.
51.Fa invp
52and
53.Fa outvp
54can refer to the same file.
55For this case, the byte ranges defined by
56.Fa *inoff ,
57.Fa *outoff and
58.Fa *len
59will not overlap.
60.Pp
61The arguments are:
62.Bl -tag -width ioflag
63.It Fa invp
64The vnode of the input file.
65.It Fa inoff
66A pointer to the file offset for the input file.
67.It Fa outvp
68The vnode of the output file.
69.It Fa outoff
70A pointer to the file offset for the output file.
71.It Fa len
72A pointer to the byte count for the copy.
73.It Fa flags
74Flags, should be set to 0 for now.
75.It Fa incred
76The credentials used to read
77.Fa invp .
78.It Fa outcred
79The credentials used to write
80.Fa outvp .
81.It Fa fsize_td
82The thread pointer to be passed to vn_rlimit_fsize().
83This will be
84.Dv NULL
85for a server thread without limits, such as for the NFS
86server or
87.Dv curthread
88otherwise.
89.El
90.Pp
91On entry and on return, the
92.Fa inoff
93and
94.Fa outoff
95arguments point to the locations of the file offsets.
96These file offsets should be updated by the number of bytes copied.
97The
98.Fa len
99argument points to the location that stores the number of bytes
100to be copied.
101Upon a successful return
102.Fa len
103will be updated to the number of bytes actually copied.
104Normally, this will be the number of bytes requested to be copied,
105however a copy of fewer bytes than requested is permitted.
106This does not necessarily indicate that the copy reached EOF on the input file.
107However, if the value pointed to by the
108.Fa len
109argument is zero upon a successful return,
110it indicates that the offset pointed to by
111.Fa inoff
112is at or beyond EOF on the input file.
113.Sh LOCKS
114The vnode are unlocked on entry and must be unlocked on return.
115The byte ranges for both
116.Fa invp
117and
118.Fa outvp
119should be range locked when this call is done.
120.Sh RETURN VALUES
121Zero is returned on success, otherwise an error code is returned.
122.Sh ERRORS
123.Bl -tag -width Er
124.It Bq Er EFBIG
125If the copy exceeds the process's file size limit or the maximum file size
126for the file system
127.Fa invp
128and
129.Fa outvp
130reside on.
131.It Bq Er EINTR
132A signal interrupted the VOP call before it could be completed.
133.It Bq Er EIO
134An I/O error occurred while reading/writing the files.
135.It Bq Er EINTEGRITY
136Corrupted data was detected while reading/writing the files.
137.It Bq Er ENOSPC
138The file system is full.
139.El
140.Sh SEE ALSO
141.Xr vn_rdwr 9 ,
142.Xr vnode 9
143