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32 * @(#)fdesc_vfsops.c 8.4 (Berkeley) 1/21/94
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/filedesc.h>
44 #include <sys/kernel.h>
46 #include <sys/mutex.h>
47 #include <sys/malloc.h>
48 #include <sys/mount.h>
50 #include <sys/resourcevar.h>
51 #include <sys/vnode.h>
53 #include <fs/fdescfs/fdesc.h>
55 static MALLOC_DEFINE(M_FDESCMNT, "FDESC mount", "FDESC mount structure");
57 static vfs_mount_t fdesc_mount;
58 static vfs_unmount_t fdesc_unmount;
59 static vfs_statfs_t fdesc_statfs;
60 static vfs_root_t fdesc_root;
63 * Mount the per-process file descriptors (/dev/fd)
66 fdesc_mount(struct mount *mp, struct thread *td)
69 struct fdescmount *fmp;
75 if (mp->mnt_flag & (MNT_UPDATE | MNT_ROOTFS))
78 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp, td);
82 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
83 M_FDESCMNT, M_WAITOK); /* XXX */
85 rvp->v_vflag |= VV_ROOT;
87 /* XXX -- don't mark as local to work around fts() problems */
88 /*mp->mnt_flag |= MNT_LOCAL;*/
89 mp->mnt_data = (qaddr_t) fmp;
92 vfs_mountedfrom(mp, "fdescfs");
97 fdesc_unmount(mp, mntflags, td)
105 if (mntflags & MNT_FORCE)
109 * Clear out buffer cache. I don't think we
110 * ever get anything cached at this level at the
111 * moment, but who knows...
113 * There is 1 extra root vnode reference corresponding
116 if ((error = vflush(mp, 1, flags, td)) != 0)
120 * Finally, throw away the fdescmount structure
122 free(mp->mnt_data, M_FDESCMNT); /* XXX */
129 fdesc_root(mp, flags, vpp, td)
138 * Return locked reference to root.
140 vp = VFSTOFDESC(mp)->f_root;
142 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
148 fdesc_statfs(mp, sbp, td)
153 struct filedesc *fdp;
160 * Compute number of free file descriptors.
161 * [ Strange results will ensue if the open file
162 * limit is ever reduced below the current number
165 PROC_LOCK(td->td_proc);
166 lim = lim_cur(td->td_proc, RLIMIT_NOFILE);
167 PROC_UNLOCK(td->td_proc);
168 fdp = td->td_proc->p_fd;
169 FILEDESC_LOCK_FAST(fdp);
170 last = min(fdp->fd_nfiles, lim);
172 for (i = fdp->fd_freefile; i < last; i++)
173 if (fdp->fd_ofiles[i] == NULL)
177 * Adjust for the fact that the fdesc array may not
178 * have been fully allocated yet.
180 if (fdp->fd_nfiles < lim)
181 freefd += (lim - fdp->fd_nfiles);
182 FILEDESC_UNLOCK_FAST(fdp);
185 sbp->f_bsize = DEV_BSIZE;
186 sbp->f_iosize = DEV_BSIZE;
187 sbp->f_blocks = 2; /* 1K to keep df happy */
190 sbp->f_files = lim + 1; /* Allow for "." */
191 sbp->f_ffree = freefd; /* See comments above */
195 static struct vfsops fdesc_vfsops = {
196 .vfs_init = fdesc_init,
197 .vfs_mount = fdesc_mount,
198 .vfs_root = fdesc_root,
199 .vfs_statfs = fdesc_statfs,
200 .vfs_unmount = fdesc_unmount,
203 VFS_SET(fdesc_vfsops, fdescfs, VFCF_SYNTHETIC);