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33 * @(#)mfs_vfsops.c 8.11 (Berkeley) 6/19/95
34 * $FreeBSD: src/sys/ufs/mfs/mfs_vfsops.c,v 1.81.2.3 2001/07/04 17:35:21 tegge Exp $
35 * $DragonFly: src/sys/vfs/mfs/mfs_vfsops.c,v 1.11 2003/08/20 09:56:32 rob Exp $
41 #include <sys/param.h>
42 #include <sys/systm.h>
44 #include <sys/kernel.h>
47 #include <sys/mount.h>
48 #include <sys/signalvar.h>
49 #include <sys/vnode.h>
50 #include <sys/malloc.h>
51 #include <sys/linker.h>
55 #include <vfs/ufs/quota.h>
56 #include <vfs/ufs/inode.h>
57 #include <vfs/ufs/ufsmount.h>
58 #include <vfs/ufs/ufs_extern.h>
59 #include <vfs/ufs/fs.h>
60 #include <vfs/ufs/ffs_extern.h>
63 #include "mfs_extern.h"
65 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
68 static int mfs_minor; /* used for building internal dev_t */
70 extern vop_t **mfs_vnodeop_p;
72 static int mfs_mount (struct mount *mp,
73 char *path, caddr_t data, struct nameidata *ndp,
75 static int mfs_start (struct mount *mp, int flags, struct thread *td);
76 static int mfs_statfs (struct mount *mp, struct statfs *sbp,
78 static int mfs_init (struct vfsconf *);
80 #define MFS_CDEV_MAJOR 253
82 static struct cdevsw mfs_cdevsw = {
84 /* maj */ MFS_CDEV_MAJOR,
92 /* write */ physwrite,
96 /* strategy */ nostrategy,
102 * mfs vfs operations.
104 static struct vfsops mfs_vfsops = {
121 VFS_SET(mfs_vfsops, mfs, 0);
127 * Called when mounting local physical media
131 * mp mount point structure
132 * path NULL (flag for root mount!!!)
135 * p process (user credentials check [statfs])
138 * mp mount point structure
139 * path path to mount point
140 * data pointer to argument struct in user space
141 * ndp mount point namei() return (used for
142 * credentials on reload), reused to look
144 * p process (user credentials check)
147 * !0 error number (errno.h)
152 * mount point is locked
154 * mount point is locked
157 * A NULL path can be used for a flag since the mount
158 * system call will fail with EFAULT in copyinstr in
159 * namei() if it is a genuine NULL from the user.
163 mfs_mount(mp, path, data, ndp, td)
167 struct nameidata *ndp;
171 struct mfs_args args;
172 struct ufsmount *ump;
174 struct mfsnode *mfsp;
180 * Use NULL path to flag a root mount
185 * Mounting root file system
190 panic("mfs_mount: mount MFS as root: not configured!");
195 * Mounting non-root file system or updating a file system
199 /* copy in user arguments*/
200 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
204 * If updating, check whether changing from read-only to
205 * read/write; if there is no device name, that's all we do.
207 if (mp->mnt_flag & MNT_UPDATE) {
215 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
217 if (mp->mnt_flag & MNT_FORCE)
219 err = ffs_flushfiles(mp, flags, td);
223 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR))
225 /* if not updating name...*/
226 if (args.fspec == 0) {
228 * Process export requests. Jumping to "success"
229 * will return the vfs_export() error code.
231 err = vfs_export(mp, &ump->um_export, &args.export);
235 /* XXX MFS does not support name updating*/
239 * Do the MALLOC before the getnewvnode since doing so afterward
240 * might cause a bogus v_data pointer to get dereferenced
241 * elsewhere if MALLOC should block.
243 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
245 err = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp);
247 FREE(mfsp, M_MFSNODE);
250 devvp->v_type = VCHR;
251 dev = make_dev(&mfs_cdevsw, mfs_minor, 0, 0, 0, "MFS%d", mfs_minor);
252 /* It is not clear that these will get initialized otherwise */
253 dev->si_bsize_phys = DEV_BSIZE;
254 dev->si_iosize_max = DFLTPHYS;
255 addaliasu(devvp, makeudev(253, mfs_minor++));
256 devvp->v_data = mfsp;
257 mfsp->mfs_baseoff = args.base;
258 mfsp->mfs_size = args.size;
259 mfsp->mfs_vnode = devvp;
261 mfsp->mfs_active = 1;
262 bufq_init(&mfsp->buf_queue);
265 * Since this is a new mount, we want the names for
266 * the device and the mount point copied in. If an
267 * error occurs, the mountpoint is discarded by the
270 /* Save "last mounted on" info for mount point (NULL pad)*/
271 copyinstr( path, /* mount point*/
272 mp->mnt_stat.f_mntonname, /* save area*/
273 MNAMELEN - 1, /* max size*/
274 &size); /* real size*/
275 bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
277 /* Save "mounted from" info for mount point (NULL pad)*/
278 copyinstr( args.fspec, /* device name*/
279 mp->mnt_stat.f_mntfromname, /* save area*/
280 MNAMELEN - 1, /* max size*/
281 &size); /* real size*/
282 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
284 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) {
285 mfsp->mfs_active = 0;
290 * Initialize FS stat information in mount struct; uses both
291 * mp->mnt_stat.f_mntonname and mp->mnt_stat.f_mntfromname
293 * This code is common to root and non-root mounts
295 (void) VFS_STATFS(mp, &mp->mnt_stat, td);
299 error_2: /* error with devvp held*/
301 /* release devvp before failing*/
304 error_1: /* no state to back out*/
311 * Used to grab the process and keep it in the kernel to service
312 * memory filesystem I/O requests.
314 * Loop servicing I/O requests.
315 * Copy the requested data into or out of the memory filesystem
320 mfs_start(struct mount *mp, int flags, struct thread *td)
322 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
323 struct mfsnode *mfsp = VTOMFS(vp);
328 * We must prevent the system from trying to swap
329 * out or kill ( when swap space is low, see vm/pageout.c ) the
330 * process. A deadlock can occur if the process is swapped out,
331 * and the system can loop trying to kill the unkillable ( while
332 * references exist ) MFS process when swap space is low.
337 while (mfsp->mfs_active) {
342 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) {
343 bufq_remove(&mfsp->buf_queue, bp);
353 * If a non-ignored signal is received, try to unmount.
354 * If that fails, clear the signal (it has been "processed"),
355 * otherwise we will loop here, as tsleep will always return
359 * Note that dounmount() may fail if work was queued after
360 * we slept. We have to jump hoops here to make sure that we
361 * process any buffers after the sleep, before we dounmount()
365 if (dounmount(mp, 0, td) != 0) {
366 KKASSERT(td->td_proc);
367 sig = CURSIG(td->td_proc);
369 SIGDELSET(td->td_proc->p_siglist, sig);
372 else if (tsleep((caddr_t)vp, PCATCH, "mfsidl", 0))
373 gotsig++; /* try to unmount in next pass */
379 * Get file system statistics.
382 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
386 error = ffs_statfs(mp, sbp, td);
387 sbp->f_type = mp->mnt_vfc->vfc_typenum;
392 * Memory based filesystem initialization.
396 struct vfsconf *vfsp;
399 cdevsw_add(&mfs_cdevsw);