NAME
vnfileops,
vn_closefile, vn_fcntl,
vn_ioctl, vn_read,
vn_poll, vn_statfile,
vn_write —
vnode file descriptor
operations
SYNOPSIS
#include
<sys/param.h>
#include <sys/file.h>
#include <sys/vnode.h>
int
vn_closefile(file_t
*fp);
int
vn_fcntl(file_t
*fp, u_int com,
void *data);
int
vn_ioctl(file_t
*fp, u_long com,
void *data);
int
vn_read(file_t
*fp, off_t *offset,
struct uio *uio,
kauth_cred_t cred,
int flags);
int
vn_poll(file_t
*fp, int
events);
int
vn_statfile(file_t
*fp, struct stat
*sb);
int
vn_write(file_t
*fp, off_t *offset,
struct uio *uio,
kauth_cred_t cred,
int flags);
DESCRIPTION
The functions described in this page are the vnode-specific file descriptor operations. They should only be accessed through the opaque function pointers in the file entries (see file(9)). They are described here only for completeness.
FUNCTIONS
vn_closefile(fp, l)- Common code for a file table vnode close operation. The file is described
by fp and l is the calling
lwp.
vn_closefile() simply calls vn_close(9) with the appropriate arguments. vn_fcntl(fp, com, data, l)- Common code for a file table vnode
fcntl(2) operation. The file is specified by
fp. The argument l is the
calling lwp.
vn_fcntl() simply locks the vnode and invokes the vnode operation VOP_FCNTL(9) with the command com and buffer data. The vnode is unlocked on return. If the operation is successful zero is returned, otherwise an appropriate error is returned. vn_ioctl(fp, com, data, l)- Common code for a file table vnode ioctl operation. The file is specified
by fp. The argument l is the
calling lwp
vn_ioctl() simply locks the vnode and invokes the vnode operation VOP_IOCTL(9) with the command com and buffer data. The vnode is unlocked on return. If the operation is successful zero is returned, otherwise an appropriate error is returned. vn_read(fp, offset, uio, cred, flags)- Common code for a file table vnode read. The argument fp is the file structure, The argument offset is the offset into the file. The argument uio is the uio structure describing the memory to read into. The caller's credentials are specified in cred. The flags argument can define FOF_UPDATE_OFFSET to update the read position in the file. If the operation is successful zero is returned, otherwise an appropriate error is returned.
vn_poll(fp, events, l)- Common code for a file table vnode poll operation.
vn_poll() simply calls VOP_POLL(9) with the events events and the calling lwp l. The function returns a bitmask of available events. vn_statfile(fp, sb, l)- Common code for a stat operation. The file descriptor is specified by the
argument fp and sb is the
buffer to return the stat information. The argument
l is the calling lwp.
vn_statfile() basically calls the vnode operation VOP_GETATTR(9) and transfer the contents of a vattr structure into a struct stat. If the operation is successful zero is returned, otherwise an appropriate error code is returned. vn_write(fp, offset, uio, cred, flags)- Common code for a file table vnode write. The argument fp is the file structure, The argument offset is the offset into the file. The argument uio is the uio structure describing the memory to read from. The caller's credentials are specified in cred. The flags argument can define FOF_UPDATE_OFFSET to update the read position in the file. If the operation is successful zero is returned, otherwise an appropriate error is returned.
CODE REFERENCES
The high-level convenience functions are implemented within the file sys/kern/vfs_vnops.c.