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

     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 8.3                       April 9, 2008                      NetBSD 8.3