table of contents
VOP_RDWR(9) | Kernel Developer's Manual | VOP_RDWR(9) |
NAME¶
VOP_READ, VOP_WRITE — read or write a fileSYNOPSIS¶
#include <sys/param.h>#include <sys/vnode.h>
#include <sys/uio.h> int
VOP_READ(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred); int
VOP_WRITE(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred);
DESCRIPTION¶
These entry points read or write the contents of a file The arguments are:- vp
- The vnode of the file.
- uio
- The location of the data to be read or written.
- ioflag
- Various flags.
- cnp
- The credentials of the caller.
IO_UNIT
- Do I/O as atomic unit.
IO_APPEND
- Append write to end.
IO_SYNC
- Do I/O synchronously.
IO_NODELOCKED
- Underlying node already locked.
IO_NDELAY
FNDELAY
flag set in file table.IO_VMIO
- Data already in VMIO space.
LOCKS¶
The file should be locked on entry and will still be locked on exit.RETURN VALUES¶
Zero is returned on success, otherwise an error code is returned.ERRORS¶
- [
EFBIG
] - An attempt was made to write a file that exceeds the process's file size limit or the maximum file size.
- [
ENOSPC
] - The file system is full.
- [
EPERM
] - An append-only flag is set on the file, but the caller is attempting to write before the current end of file.
SEE ALSO¶
uiomove(9), vnode(9)AUTHORS¶
This manual page was written by Doug Rabson.July 24, 1996 | Debian |