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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 1.23 2005/07/26 15:43:35 hmp 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 = {
109 .vfs_mount = mfs_mount,
110 .vfs_start = mfs_start,
111 .vfs_unmount = ffs_unmount,
112 .vfs_root = ufs_root,
113 .vfs_quotactl = ufs_quotactl,
114 .vfs_statfs = mfs_statfs,
115 .vfs_sync = ffs_sync,
116 .vfs_vget = ffs_vget,
117 .vfs_fhtovp = ffs_fhtovp,
118 .vfs_checkexp = ufs_check_export,
119 .vfs_vptofh = ffs_vptofh,
123 VFS_SET(mfs_vfsops, mfs, 0);
126 * We allow the underlying MFS block device to be opened and read.
129 mfsopen(dev_t dev, int flags, int mode, struct thread *td)
139 mfsclose(dev_t dev, int flags, int mode, struct thread *td)
145 mfsstrategy(struct buf *bp)
147 struct mfsnode *mfsp;
149 if ((mfsp = bp->b_dev->si_drv1) != NULL) {
150 off_t boff = (off_t)bp->b_blkno << DEV_BSHIFT;
151 off_t eoff = boff + bp->b_bcount;
153 if (eoff <= mfsp->mfs_size) {
154 bufq_insert_tail(&mfsp->buf_queue, bp);
155 wakeup((caddr_t)mfsp);
156 } else if (boff < mfsp->mfs_size) {
157 bp->b_bcount = mfsp->mfs_size - boff;
158 bufq_insert_tail(&mfsp->buf_queue, bp);
159 wakeup((caddr_t)mfsp);
160 } else if (boff == mfsp->mfs_size) {
161 bp->b_resid = bp->b_bcount;
164 bp->b_error = EINVAL;
169 bp->b_flags |= B_ERROR;
177 * Called when mounting local physical media
181 * mp mount point structure
182 * path NULL (flag for root mount!!!)
185 * p process (user credentials check [statfs])
188 * mp mount point structure
189 * path path to mount point
190 * data pointer to argument struct in user space
191 * ndp mount point namei() return (used for
192 * credentials on reload), reused to look
194 * p process (user credentials check)
197 * !0 error number (errno.h)
202 * mount point is locked
204 * mount point is locked
207 * A NULL path can be used for a flag since the mount
208 * system call will fail with EFAULT in copyinstr in
209 * namei() if it is a genuine NULL from the user.
213 mfs_mount(struct mount *mp, char *path, caddr_t data, struct thread *td)
216 struct mfs_args args;
217 struct ufsmount *ump;
219 struct mfsnode *mfsp;
226 * Use NULL path to flag a root mount
231 * Mounting root file system
236 panic("mfs_mount: mount MFS as root: not configured!");
241 * Mounting non-root file system or updating a file system
245 /* copy in user arguments*/
246 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
250 * If updating, check whether changing from read-only to
251 * read/write; if there is no device name, that's all we do.
253 if (mp->mnt_flag & MNT_UPDATE) {
261 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
263 if (mp->mnt_flag & MNT_FORCE)
265 err = ffs_flushfiles(mp, flags, td);
269 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR))
271 /* if not updating name...*/
272 if (args.fspec == 0) {
274 * Process export requests. Jumping to "success"
275 * will return the vfs_export() error code.
277 err = vfs_export(mp, &ump->um_export, &args.export);
281 /* XXX MFS does not support name updating*/
285 * Do the MALLOC before the getnewvnode since doing so afterward
286 * might cause a bogus v_data pointer to get dereferenced
287 * elsewhere if MALLOC should block.
289 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
291 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops, &devvp, 0, 0);
293 FREE(mfsp, M_MFSNODE);
297 minnum = (curproc->p_pid & 0xFF) |
298 ((curproc->p_pid & ~0xFF) << 8);
300 devvp->v_type = VCHR;
301 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600,
302 "MFS%d", minnum >> 16);
303 /* It is not clear that these will get initialized otherwise */
304 dev->si_bsize_phys = DEV_BSIZE;
305 dev->si_iosize_max = DFLTPHYS;
307 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum));
308 devvp->v_data = mfsp;
309 mfsp->mfs_baseoff = args.base;
310 mfsp->mfs_size = args.size;
311 mfsp->mfs_vnode = devvp;
312 mfsp->mfs_dev = reference_dev(dev);
314 mfsp->mfs_active = 1;
315 bufq_init(&mfsp->buf_queue);
317 /* Save "mounted from" info for mount point (NULL pad)*/
318 copyinstr( args.fspec, /* device name*/
319 mp->mnt_stat.f_mntfromname, /* save area*/
320 MNAMELEN - 1, /* max size*/
321 &size); /* real size*/
322 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
325 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) {
326 mfsp->mfs_active = 0;
331 * Initialize FS stat information in mount struct; uses
332 * mp->mnt_stat.f_mntfromname.
334 * This code is common to root and non-root mounts
336 (void) VFS_STATFS(mp, &mp->mnt_stat, td);
340 error_2: /* error with devvp held*/
342 /* release devvp before failing*/
345 error_1: /* no state to back out*/
352 * Used to grab the process and keep it in the kernel to service
353 * memory filesystem I/O requests.
355 * Loop servicing I/O requests.
356 * Copy the requested data into or out of the memory filesystem
361 mfs_start(struct mount *mp, int flags, struct thread *td)
363 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
364 struct mfsnode *mfsp = VTOMFS(vp);
369 * We must prevent the system from trying to swap
370 * out or kill ( when swap space is low, see vm/pageout.c ) the
371 * process. A deadlock can occur if the process is swapped out,
372 * and the system can loop trying to kill the unkillable ( while
373 * references exist ) MFS process when swap space is low.
378 while (mfsp->mfs_active) {
382 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) {
383 bufq_remove(&mfsp->buf_queue, bp);
393 * If a non-ignored signal is received, try to unmount.
394 * If that fails, clear the signal (it has been "processed"),
395 * otherwise we will loop here, as tsleep will always return
399 * Note that dounmount() may fail if work was queued after
400 * we slept. We have to jump hoops here to make sure that we
401 * process any buffers after the sleep, before we dounmount()
405 if (dounmount(mp, 0, td) != 0) {
406 KKASSERT(td->td_proc);
407 sig = CURSIG(td->td_proc);
409 SIGDELSET(td->td_proc->p_siglist, sig);
412 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0))
413 gotsig++; /* try to unmount in next pass */
416 v_release_rdev(vp); /* hack because we do not implement CLOSE */
417 /* XXX destroy/release devvp */
422 * Get file system statistics.
425 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
429 error = ffs_statfs(mp, sbp, td);
430 sbp->f_type = mp->mnt_vfc->vfc_typenum;
435 * Memory based filesystem initialization.
438 mfs_init(struct vfsconf *vfsp)
440 cdevsw_add(&mfs_cdevsw, 0, 0);