VNFILEOPS(9) BSD Kernel Developer's Manual VNFILEOPS(9)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 descrip‐
tor 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 opera‐
tion 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 mem‐
ory 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 speci‐
fied 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 appropri‐
ate 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 mem‐
ory 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.
SEE ALSOfile(9), intro(9), vnode(9), vnodeops(9), vnsubr(9)BSD April 9, 2008 BSD
