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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 1.22 2005/06/06 15:09:38 drhodus 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>
52 #include <sys/fcntl.h>
56 #include <sys/thread2.h>
58 #include <vfs/ufs/quota.h>
59 #include <vfs/ufs/inode.h>
60 #include <vfs/ufs/ufsmount.h>
61 #include <vfs/ufs/ufs_extern.h>
62 #include <vfs/ufs/fs.h>
63 #include <vfs/ufs/ffs_extern.h>
66 #include "mfs_extern.h"
68 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
71 extern struct vop_ops *mfs_vnode_vops;
73 static int mfs_mount (struct mount *mp,
74 char *path, caddr_t data, struct thread *td);
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 *);
82 d_strategy_t mfsstrategy;
84 #define MFS_CDEV_MAJOR 253
86 static struct cdevsw mfs_cdevsw = {
88 /* maj */ MFS_CDEV_MAJOR,
96 /* write */ physwrite,
100 /* strategy */ mfsstrategy,
106 * mfs vfs operations.
108 static struct vfsops mfs_vfsops = {
125 VFS_SET(mfs_vfsops, mfs, 0);
128 * We allow the underlying MFS block device to be opened and read.
131 mfsopen(dev_t dev, int flags, int mode, struct thread *td)
141 mfsclose(dev_t dev, int flags, int mode, struct thread *td)
147 mfsstrategy(struct buf *bp)
149 struct mfsnode *mfsp;
151 if ((mfsp = bp->b_dev->si_drv1) != NULL) {
152 off_t boff = (off_t)bp->b_blkno << DEV_BSHIFT;
153 off_t eoff = boff + bp->b_bcount;
155 if (eoff <= mfsp->mfs_size) {
156 bufq_insert_tail(&mfsp->buf_queue, bp);
157 wakeup((caddr_t)mfsp);
158 } else if (boff < mfsp->mfs_size) {
159 bp->b_bcount = mfsp->mfs_size - boff;
160 bufq_insert_tail(&mfsp->buf_queue, bp);
161 wakeup((caddr_t)mfsp);
162 } else if (boff == mfsp->mfs_size) {
163 bp->b_resid = bp->b_bcount;
166 bp->b_error = EINVAL;
171 bp->b_flags |= B_ERROR;
179 * Called when mounting local physical media
183 * mp mount point structure
184 * path NULL (flag for root mount!!!)
187 * p process (user credentials check [statfs])
190 * mp mount point structure
191 * path path to mount point
192 * data pointer to argument struct in user space
193 * ndp mount point namei() return (used for
194 * credentials on reload), reused to look
196 * p process (user credentials check)
199 * !0 error number (errno.h)
204 * mount point is locked
206 * mount point is locked
209 * A NULL path can be used for a flag since the mount
210 * system call will fail with EFAULT in copyinstr in
211 * namei() if it is a genuine NULL from the user.
215 mfs_mount(struct mount *mp, char *path, caddr_t data, struct thread *td)
218 struct mfs_args args;
219 struct ufsmount *ump;
221 struct mfsnode *mfsp;
228 * Use NULL path to flag a root mount
233 * Mounting root file system
238 panic("mfs_mount: mount MFS as root: not configured!");
243 * Mounting non-root file system or updating a file system
247 /* copy in user arguments*/
248 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
252 * If updating, check whether changing from read-only to
253 * read/write; if there is no device name, that's all we do.
255 if (mp->mnt_flag & MNT_UPDATE) {
263 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
265 if (mp->mnt_flag & MNT_FORCE)
267 err = ffs_flushfiles(mp, flags, td);
271 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR))
273 /* if not updating name...*/
274 if (args.fspec == 0) {
276 * Process export requests. Jumping to "success"
277 * will return the vfs_export() error code.
279 err = vfs_export(mp, &ump->um_export, &args.export);
283 /* XXX MFS does not support name updating*/
287 * Do the MALLOC before the getnewvnode since doing so afterward
288 * might cause a bogus v_data pointer to get dereferenced
289 * elsewhere if MALLOC should block.
291 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
293 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops, &devvp, 0, 0);
295 FREE(mfsp, M_MFSNODE);
299 minnum = (curproc->p_pid & 0xFF) |
300 ((curproc->p_pid & ~0xFF) << 8);
302 devvp->v_type = VCHR;
303 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600,
304 "MFS%d", minnum >> 16);
305 /* It is not clear that these will get initialized otherwise */
306 dev->si_bsize_phys = DEV_BSIZE;
307 dev->si_iosize_max = DFLTPHYS;
309 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum));
310 devvp->v_data = mfsp;
311 mfsp->mfs_baseoff = args.base;
312 mfsp->mfs_size = args.size;
313 mfsp->mfs_vnode = devvp;
314 mfsp->mfs_dev = reference_dev(dev);
316 mfsp->mfs_active = 1;
317 bufq_init(&mfsp->buf_queue);
319 /* Save "mounted from" info for mount point (NULL pad)*/
320 copyinstr( args.fspec, /* device name*/
321 mp->mnt_stat.f_mntfromname, /* save area*/
322 MNAMELEN - 1, /* max size*/
323 &size); /* real size*/
324 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
327 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) {
328 mfsp->mfs_active = 0;
333 * Initialize FS stat information in mount struct; uses
334 * mp->mnt_stat.f_mntfromname.
336 * This code is common to root and non-root mounts
338 (void) VFS_STATFS(mp, &mp->mnt_stat, td);
342 error_2: /* error with devvp held*/
344 /* release devvp before failing*/
347 error_1: /* no state to back out*/
354 * Used to grab the process and keep it in the kernel to service
355 * memory filesystem I/O requests.
357 * Loop servicing I/O requests.
358 * Copy the requested data into or out of the memory filesystem
363 mfs_start(struct mount *mp, int flags, struct thread *td)
365 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
366 struct mfsnode *mfsp = VTOMFS(vp);
371 * We must prevent the system from trying to swap
372 * out or kill ( when swap space is low, see vm/pageout.c ) the
373 * process. A deadlock can occur if the process is swapped out,
374 * and the system can loop trying to kill the unkillable ( while
375 * references exist ) MFS process when swap space is low.
380 while (mfsp->mfs_active) {
384 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) {
385 bufq_remove(&mfsp->buf_queue, bp);
395 * If a non-ignored signal is received, try to unmount.
396 * If that fails, clear the signal (it has been "processed"),
397 * otherwise we will loop here, as tsleep will always return
401 * Note that dounmount() may fail if work was queued after
402 * we slept. We have to jump hoops here to make sure that we
403 * process any buffers after the sleep, before we dounmount()
407 if (dounmount(mp, 0, td) != 0) {
408 KKASSERT(td->td_proc);
409 sig = CURSIG(td->td_proc);
411 SIGDELSET(td->td_proc->p_siglist, sig);
414 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0))
415 gotsig++; /* try to unmount in next pass */
418 v_release_rdev(vp); /* hack because we do not implement CLOSE */
419 /* XXX destroy/release devvp */
424 * Get file system statistics.
427 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
431 error = ffs_statfs(mp, sbp, td);
432 sbp->f_type = mp->mnt_vfc->vfc_typenum;
437 * Memory based filesystem initialization.
440 mfs_init(struct vfsconf *vfsp)
442 cdevsw_add(&mfs_cdevsw, 0, 0);