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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 1.15 2004/05/19 22:53:04 dillon 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 <vfs/ufs/quota.h>
57 #include <vfs/ufs/inode.h>
58 #include <vfs/ufs/ufsmount.h>
59 #include <vfs/ufs/ufs_extern.h>
60 #include <vfs/ufs/fs.h>
61 #include <vfs/ufs/ffs_extern.h>
64 #include "mfs_extern.h"
66 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
69 extern vop_t **mfs_vnodeop_p;
71 static int mfs_mount (struct mount *mp,
72 char *path, caddr_t data, struct nameidata *ndp,
74 static int mfs_start (struct mount *mp, int flags, struct thread *td);
75 static int mfs_statfs (struct mount *mp, struct statfs *sbp,
77 static int mfs_init (struct vfsconf *);
81 d_strategy_t mfsstrategy;
83 #define MFS_CDEV_MAJOR 253
85 static struct cdevsw mfs_cdevsw = {
87 /* maj */ MFS_CDEV_MAJOR,
95 /* write */ physwrite,
99 /* strategy */ mfsstrategy,
105 * mfs vfs operations.
107 static struct vfsops mfs_vfsops = {
124 VFS_SET(mfs_vfsops, mfs, 0);
127 * We allow the underlying MFS block device to be opened and read.
130 mfsopen(dev_t dev, int flags, int mode, struct thread *td)
140 mfsclose(dev_t dev, int flags, int mode, struct thread *td)
146 mfsstrategy(struct buf *bp)
148 struct mfsnode *mfsp;
150 if ((mfsp = bp->b_dev->si_drv1) != NULL) {
151 off_t boff = (off_t)bp->b_blkno << DEV_BSHIFT;
152 off_t eoff = boff + bp->b_bcount;
154 if (eoff <= mfsp->mfs_size) {
155 bufq_insert_tail(&mfsp->buf_queue, bp);
156 wakeup((caddr_t)mfsp);
157 } else if (boff < mfsp->mfs_size) {
158 bp->b_bcount = mfsp->mfs_size - boff;
159 bufq_insert_tail(&mfsp->buf_queue, bp);
160 wakeup((caddr_t)mfsp);
161 } else if (boff == mfsp->mfs_size) {
162 bp->b_resid = bp->b_bcount;
165 bp->b_error = EINVAL;
170 bp->b_flags |= B_ERROR;
178 * Called when mounting local physical media
182 * mp mount point structure
183 * path NULL (flag for root mount!!!)
186 * p process (user credentials check [statfs])
189 * mp mount point structure
190 * path path to mount point
191 * data pointer to argument struct in user space
192 * ndp mount point namei() return (used for
193 * credentials on reload), reused to look
195 * p process (user credentials check)
198 * !0 error number (errno.h)
203 * mount point is locked
205 * mount point is locked
208 * A NULL path can be used for a flag since the mount
209 * system call will fail with EFAULT in copyinstr in
210 * namei() if it is a genuine NULL from the user.
214 mfs_mount(struct mount *mp, char *path, caddr_t data, struct nameidata *ndp,
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 = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp);
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);
320 * Since this is a new mount, we want the names for
321 * the device and the mount point copied in. If an
322 * error occurs, the mountpoint is discarded by the
325 /* Save "last mounted on" info for mount point (NULL pad)*/
326 copyinstr( path, /* mount point*/
327 mp->mnt_stat.f_mntonname, /* save area*/
328 MNAMELEN - 1, /* max size*/
329 &size); /* real size*/
330 bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
332 /* Save "mounted from" info for mount point (NULL pad)*/
333 copyinstr( args.fspec, /* device name*/
334 mp->mnt_stat.f_mntfromname, /* save area*/
335 MNAMELEN - 1, /* max size*/
336 &size); /* real size*/
337 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
339 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) {
340 mfsp->mfs_active = 0;
345 * Initialize FS stat information in mount struct; uses both
346 * mp->mnt_stat.f_mntonname and mp->mnt_stat.f_mntfromname
348 * This code is common to root and non-root mounts
350 (void) VFS_STATFS(mp, &mp->mnt_stat, td);
354 error_2: /* error with devvp held*/
356 /* release devvp before failing*/
359 error_1: /* no state to back out*/
366 * Used to grab the process and keep it in the kernel to service
367 * memory filesystem I/O requests.
369 * Loop servicing I/O requests.
370 * Copy the requested data into or out of the memory filesystem
375 mfs_start(struct mount *mp, int flags, struct thread *td)
377 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
378 struct mfsnode *mfsp = VTOMFS(vp);
383 * We must prevent the system from trying to swap
384 * out or kill ( when swap space is low, see vm/pageout.c ) the
385 * process. A deadlock can occur if the process is swapped out,
386 * and the system can loop trying to kill the unkillable ( while
387 * references exist ) MFS process when swap space is low.
392 while (mfsp->mfs_active) {
397 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) {
398 bufq_remove(&mfsp->buf_queue, bp);
408 * If a non-ignored signal is received, try to unmount.
409 * If that fails, clear the signal (it has been "processed"),
410 * otherwise we will loop here, as tsleep will always return
414 * Note that dounmount() may fail if work was queued after
415 * we slept. We have to jump hoops here to make sure that we
416 * process any buffers after the sleep, before we dounmount()
420 if (dounmount(mp, 0, td) != 0) {
421 KKASSERT(td->td_proc);
422 sig = CURSIG(td->td_proc);
424 SIGDELSET(td->td_proc->p_siglist, sig);
427 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0))
428 gotsig++; /* try to unmount in next pass */
431 v_release_rdev(vp); /* hack because we do not implement CLOSE */
432 /* XXX destroy/release devvp */
437 * Get file system statistics.
440 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
444 error = ffs_statfs(mp, sbp, td);
445 sbp->f_type = mp->mnt_vfc->vfc_typenum;
450 * Memory based filesystem initialization.
453 mfs_init(struct vfsconf *vfsp)
455 cdevsw_add(&mfs_cdevsw, 0, 0);