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share/man/man9/VOP_COPY_FILE_RANGE.9

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				.Dd June 20, 2019
				asomersUnsubmitted Not Done Inline Actions Also update this date when you commit. asomers: Also update this date when you commit.
				.Dt VOP_COPY_FILE_RANGE 9
				.Os
				.Sh NAME
				.Nm VOP_COPY_FILE_RANGE
				.Nd copy a byte range from one regular file to another within a file system
				.Sh SYNOPSIS
				.In sys/param.h
				.In sys/vnode.h
				.Ft int
				.Fo VOP_COPY_FILE_RANGE
				.Fa "struct vnode *invp"
				kibUnsubmitted Done Inline Actions Use .Fo to avoid such long line. kib: Use .Fo to avoid such long line.
				.Fa "off_t *inoff"
				.Fa "struct vnode *outvp"
				.Fa "off_t *outoff"
				.Fa "size_t *len"
				.Fa "unsigned int flags"
				.Fa "struct ucred *incred"
				.Fa "struct ucred *outcred"
				.Fa "struct thread *fsize_td"
				.Sh DESCRIPTION
				This entry point copies a byte range from one regular file to another within a
				file system.
				.Pp
				The arguments are:
				.Bl -tag -width ioflag
				.It Fa invp
				The vnode of the input file.
				.It Fa inoff
				A pointer to the file offset for the input file.
				.It Fa outvp
				The vnode of the output file.
				.It Fa outoff
				A pointer to the file offset for the output file.
				.It Fa len
				A pointer to the number of bytes to be copied.
				.It Fa flags
				Flags, should be set to 0 for now.
				.It Fa incred
				The credentials used to read
				.Fa invp .
				.It Fa outcred
				The credentials used to write
				.Fa outvp .
				.It Fa 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
				asomersUnsubmitted Done Inline Actions NULL should use `.Dv`. asomers: NULL should use `.Dv`.
				server or curthread otherwise.
				asomersUnsubmitted Done Inline Actions `curthread` should also use `.Dv` asomers: `curthread` should also use `.Dv`
				.El
				asomersUnsubmitted Done Inline Actions When the call "is done" or "is made"? asomers: When the call "is done" or "is made"?
				.Pp
				When the call is done, the
				asomersUnsubmitted Done Inline Actions Will the byte ranges be locked on entry? asomers: Will the byte ranges be locked on entry?
				.Fa inoff
				and
				.Fa outoff
				arguments point to the locations of the file offsets.
				These file offsets should be updated by the number of bytes copied.
				asomersUnsubmitted Done Inline Actions This line should probably read "on return", too. asomers: This line should probably read "on return", too.
				The
				.Fa len
				argument points to the location that stores the number of bytes
				to be copied.
				It should be reduced by the number of bytes copied, which implies that
				the value pointed to by
				.Fa len
				will normally be zero for a non-error return.
				However, a copy of less bytes than requested is permitted.
				.Sh LOCKS
				The vnodes are unlocked when the call is done and should be unlocked
				asomersUnsubmitted Done Inline Actions "is done" is ambiguous. Does that refer to before or after? Better to use the terminology used by other VOP man pages: "on entry" and "on return". asomers: "is done" is ambiguous. Does that refer to before or after? Better to use the terminology…
				when the call returns.
				The byte ranges for both
				.Fa invp
				and
				.Fa outvp
				should be range locked when this call is done.
				.Sh RETURN VALUES
				Zero is returned on success, otherwise an error code is returned.
				.Sh ERRORS
				.Bl -tag -width Er
				.It Bq Er EFBIG
				If the copy exceeds the process's file size limit or the maximum file size
				for the file system
				.Fa invp
				and
				.Fa outvp
				reside on.
				.It Bq Er EINTR
				A signal interrupted the VOP call before it could be completed.
				.It Bq Er EIO
				An I/O error occurred while reading/writing the files.
				.It Bq Er ENOSPC
				The file system is full.
				.El
				.Sh SEE ALSO
				.Xr vn_rdwr 9 ,
				.Xr vnode 9