include/sys/vfs_dispatch.h

   1 /*
   2  * Copyright 2017 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifndef _SYS_VFS_DISPATCH_H
  18 #define _SYS_VFS_DISPATCH_H
  19
  20 #include <sys/vfs.h>
  21 #include <sys/stdbool.h>
  22 #include <sys/fem.h>
  23
  24 /*
  25  * Ideally these static inlines could be just inline statements in the
  26  * corresponding fsop_*() functions.  Unfortunately, fem gets in the way and
  27  * we have to make these to centralize the damage.
  28  *
  29  * See comment in sys/vnode_dispatch.h for more details and an example.
  30  */
  31
  32 #define VFS_DISPATCH(fname, opname, vheadname, args, callargs)          \
  33 static inline int fname args                                            \
  34 {                                                                       \
  35         if (check_fem && vfs->vfs_femhead != NULL)                      \
  36                 return vheadname callargs;                              \
  37         if (vfs->vfs_op->opname == NULL)                                \
  38                 return ENOSYS;                                          \
  39         return vfs->vfs_op->opname callargs;                            \
  40 }
  41
  42 VFS_DISPATCH(fsop_mount_dispatch, vfs_mount, fshead_mount,
  43     (struct vfs *vfs, struct vnode *mvnode, struct mounta *uap, cred_t *cr,
  44      bool check_fem),
  45     (vfs, mvnode, uap, cr))
  46 VFS_DISPATCH(fsop_unmount_dispatch, vfs_unmount, fshead_unmount,
  47     (struct vfs *vfs, int flag, cred_t *cr, bool check_fem),
  48     (vfs, flag, cr))
  49 VFS_DISPATCH(fsop_root_dispatch, vfs_root, fshead_root,
  50     (struct vfs *vfs, struct vnode **vnode, bool check_fem),
  51     (vfs, vnode))
  52 VFS_DISPATCH(fsop_statfs_dispatch, vfs_statvfs, fshead_statvfs,
  53     (struct vfs *vfs, statvfs64_t *sp, bool check_fem),
  54     (vfs, sp))
  55
  56 /* no-op by default, so it is hand-coded */
  57 static inline int fsop_sync_dispatch(struct vfs *vfs, short flag, cred_t *cr,
  58                                      bool check_fem)
  59 {
  60         if (check_fem && vfs->vfs_femhead != NULL)
  61                 return fshead_sync(vfs, flag, cr);
  62
  63         if (vfs->vfs_op->vfs_sync == NULL)
  64                 return 0;
  65
  66         return vfs->vfs_op->vfs_sync(vfs, flag, cr);
  67 }
  68
  69 VFS_DISPATCH(fsop_vget_dispatch, vfs_vget, fshead_vget,
  70     (struct vfs *vfs, struct vnode **vnode, fid_t *fid, bool check_fem),
  71     (vfs, vnode, fid))
  72 VFS_DISPATCH(fsop_mountroot_dispatch, vfs_mountroot, fshead_mountroot,
  73     (struct vfs *vfs, enum whymountroot reason, bool check_fem),
  74     (vfs, reason))
  75
  76 /* returns void, so it is hand-coded */
  77 static inline void fsop_freefs_dispatch(struct vfs *vfs, bool check_fem)
  78 {
  79         if (check_fem && vfs->vfs_femhead != NULL)
  80                 fshead_freevfs(vfs);
  81         else if (vfs->vfs_op->vfs_freevfs != NULL)
  82                 vfs->vfs_op->vfs_freevfs(vfs);
  83 }
  84
  85 VFS_DISPATCH(fsop_vnstate_dispatch, vfs_vnstate, fshead_vnstate,
  86     (struct vfs *vfs, struct vnode *vnode, vntrans_t nstate, bool check_fem),
  87     (vfs, vnode, nstate))
  88
  89 #undef VFS_DISPATCH
  90
  91 #endif