vnfileops(9) - NetBSD Manual Pages

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VNFILEOPS(9)           NetBSD 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

     This section describes places within the NetBSD source tree where actual
     code implementing or using the vnode framework can be found.  All path-
     names are relative to /usr/src.

     The high-level convenience functions are implemented within the file
     sys/kern/vfs_vnops.c.


SEE ALSO

     file(9), intro(9), vnode(9), vnodeops(9), vnsubr(9)

NetBSD 5.1                       April 9, 2008                      NetBSD 5.1