VOP_COPY_FILE_RANGE(9)                       FreeBSD Kernel Developer's Manual

NAME
     VOP_COPY_FILE_RANGE - copy a byte range from one file to another or
     within one file in a single file system

SYNOPSIS
     #include <sys/param.h>
     #include <sys/vnode.h>

     int
     VOP_COPY_FILE_RANGE(struct vnode *invp, off_t *inoff,
         struct vnode *outvp, off_t *outoff, size_t *len, unsigned int flags,
         struct ucred *incred, struct ucred *outcred,
         struct thread *fsize_td);

DESCRIPTION
     This entry point copies a byte range from one regular file to another or
     within one file in a single file system.  invp and outvp can refer to the
     same file.  For this case, the byte ranges defined by *inoff, *outoff and
     *len will not overlap.

     The arguments are:

     invp    The vnode of the input file.

     inoff   A pointer to the file offset for the input file.

     outvp   The vnode of the output file.

     outoff  A pointer to the file offset for the output file.

     len     A pointer to the byte count for the copy.

     flags   Flags, should be set to 0 for now.

     incred  The credentials used to read invp.

     outcred
             The credentials used to write outvp.

     fsize_td
             The thread pointer to be passed to vn_rlimit_fsize().  This will
             be NULL for a server thread without limits, such as for the NFS
             server or curthread otherwise.

     On entry and on return, the inoff and outoff arguments point to the
     locations of the file offsets.  These file offsets should be updated by
     the number of bytes copied.  The len argument points to the location that
     stores the number of bytes to be copied.  Upon a successful return len
     will be updated to the number of bytes actually copied.  Normally, this
     will be the number of bytes requested to be copied, however a copy of
     fewer bytes than requested is permitted.  This does not necessarily
     indicate that the copy reached EOF on the input file.  However, if the
     value pointed to by the len argument is zero upon a successful return, it
     indicates that the offset pointed to by inoff is at or beyond EOF on the
     input file.

LOCKS
     The vnode are unlocked on entry and must be unlocked on return.  The byte
     ranges for both invp and outvp should be range locked when this call is
     done.

RETURN VALUES
     Zero is returned on success, otherwise an error code is returned.

ERRORS
     [EFBIG]            If the copy exceeds the process's file size limit or
                        the maximum file size for the file system invp and
                        outvp reside on.

     [EINTR]            A signal interrupted the VOP call before it could be
                        completed.

     [EIO]              An I/O error occurred while reading/writing the files.

     [EINTEGRITY]       Corrupted data was detected while reading/writing the
                        files.

     [ENOSPC]           The file system is full.

SEE ALSO
     vn_rdwr(9), vnode(9)

FreeBSD 13.1-RELEASE-p6         March 30, 2020         FreeBSD 13.1-RELEASE-p6