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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 1.32 2006/05/11 08:23:20 swildner Exp $
39 #include <sys/param.h>
40 #include <sys/systm.h>
42 #include <sys/kernel.h>
45 #include <sys/mount.h>
46 #include <sys/signalvar.h>
47 #include <sys/vnode.h>
48 #include <sys/malloc.h>
49 #include <sys/linker.h>
50 #include <sys/fcntl.h>
53 #include <vm/vm_object.h>
54 #include <vm/vm_page.h>
55 #include <vm/vm_pager.h>
56 #include <vm/vnode_pager.h>
59 #include <sys/thread2.h>
61 #include <vfs/ufs/quota.h>
62 #include <vfs/ufs/inode.h>
63 #include <vfs/ufs/ufsmount.h>
64 #include <vfs/ufs/ufs_extern.h>
65 #include <vfs/ufs/fs.h>
66 #include <vfs/ufs/ffs_extern.h>
69 #include "mfs_extern.h"
71 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
74 extern struct vop_ops *mfs_vnode_vops;
76 static int mfs_mount (struct mount *mp,
77 char *path, caddr_t data, struct ucred *td);
78 static int mfs_start (struct mount *mp, int flags);
79 static int mfs_statfs (struct mount *mp, struct statfs *sbp,
81 static int mfs_init (struct vfsconf *);
85 d_strategy_t mfsstrategy;
87 #define MFS_CDEV_MAJOR 253
89 static struct cdevsw mfs_cdevsw = {
91 /* maj */ MFS_CDEV_MAJOR,
99 /* write */ physwrite,
103 /* strategy */ mfsstrategy,
109 * mfs vfs operations.
111 static struct vfsops mfs_vfsops = {
112 .vfs_mount = mfs_mount,
113 .vfs_start = mfs_start,
114 .vfs_unmount = ffs_unmount,
115 .vfs_root = ufs_root,
116 .vfs_quotactl = ufs_quotactl,
117 .vfs_statfs = mfs_statfs,
118 .vfs_sync = ffs_sync,
119 .vfs_vget = ffs_vget,
120 .vfs_fhtovp = ffs_fhtovp,
121 .vfs_checkexp = ufs_check_export,
122 .vfs_vptofh = ffs_vptofh,
126 VFS_SET(mfs_vfsops, mfs, 0);
129 * We allow the underlying MFS block device to be opened and read.
132 mfsopen(dev_t dev, int flags, int mode, struct thread *td)
142 mfsclose(dev_t dev, int flags, int mode, struct thread *td)
148 mfsstrategy(dev_t dev, struct bio *bio)
150 struct buf *bp = bio->bio_buf;
151 off_t boff = bio->bio_offset;
152 off_t eoff = boff + bp->b_bcount;
153 struct mfsnode *mfsp;
155 if ((mfsp = dev->si_drv1) == NULL) {
161 if (eoff > mfsp->mfs_size) {
162 if (boff > mfsp->mfs_size || (bp->b_flags & B_BNOCLIP))
165 * Return EOF by completing the I/O with 0 bytes transfered.
166 * Set B_INVAL to indicate that any data in the buffer is not
169 if (boff == mfsp->mfs_size) {
170 bp->b_resid = bp->b_bcount;
171 bp->b_flags |= B_INVAL;
174 bp->b_bcount = mfsp->mfs_size - boff;
180 bioq_insert_tail(&mfsp->bio_queue, bio);
181 wakeup((caddr_t)mfsp);
185 * Failure conditions on bio
188 bp->b_error = EINVAL;
190 bp->b_flags |= B_ERROR | B_INVAL;
198 * Called when mounting local physical media
202 * mp mount point structure
203 * path NULL (flag for root mount!!!)
206 * p process (user credentials check [statfs])
209 * mp mount point structure
210 * path path to mount point
211 * data pointer to argument struct in user space
212 * ndp mount point namei() return (used for
213 * credentials on reload), reused to look
215 * p process (user credentials check)
218 * !0 error number (errno.h)
223 * mount point is locked
225 * mount point is locked
228 * A NULL path can be used for a flag since the mount
229 * system call will fail with EFAULT in copyinstr in
230 * namei() if it is a genuine NULL from the user.
234 mfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
237 struct mfs_args args;
238 struct ufsmount *ump;
240 struct mfsnode *mfsp;
247 * Use NULL path to flag a root mount
252 * Mounting root file system
257 panic("mfs_mount: mount MFS as root: not configured!");
262 * Mounting non-root file system or updating a file system
266 /* copy in user arguments*/
267 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
271 * If updating, check whether changing from read-only to
272 * read/write; if there is no device name, that's all we do.
274 if (mp->mnt_flag & MNT_UPDATE) {
282 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
284 if (mp->mnt_flag & MNT_FORCE)
286 err = ffs_flushfiles(mp, flags);
290 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
291 /* XXX reopen the device vnode read-write */
294 /* if not updating name...*/
295 if (args.fspec == 0) {
297 * Process export requests. Jumping to "success"
298 * will return the vfs_export() error code.
300 err = vfs_export(mp, &ump->um_export, &args.export);
304 /* XXX MFS does not support name updating*/
308 * Do the MALLOC before the getnewvnode since doing so afterward
309 * might cause a bogus v_data pointer to get dereferenced
310 * elsewhere if MALLOC should block.
312 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
314 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops, &devvp, 0, 0);
316 FREE(mfsp, M_MFSNODE);
320 minnum = (curproc->p_pid & 0xFF) |
321 ((curproc->p_pid & ~0xFF) << 8);
323 devvp->v_type = VCHR;
324 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600,
325 "MFS%d", minnum >> 16);
326 /* It is not clear that these will get initialized otherwise */
327 dev->si_bsize_phys = DEV_BSIZE;
328 dev->si_iosize_max = DFLTPHYS;
330 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum));
331 devvp->v_data = mfsp;
332 mfsp->mfs_baseoff = args.base;
333 mfsp->mfs_size = args.size;
334 mfsp->mfs_vnode = devvp;
335 mfsp->mfs_dev = reference_dev(dev);
336 mfsp->mfs_td = curthread;
337 mfsp->mfs_active = 1;
338 bioq_init(&mfsp->bio_queue);
341 * Our 'block' device must be backed by a VM object. Theoretically
342 * we could use the anonymous memory VM object supplied by userland,
343 * but it would be somewhat of a complex task to deal with it
344 * that way since it would result in I/O requests which supply
345 * the VM pages from our own object.
347 * vnode_pager_alloc() is typically called when a VM object is
348 * being referenced externally. We have to undo the refs for
349 * the self reference between vnode and object.
351 vnode_pager_alloc(devvp, args.size, 0, 0);
353 --devvp->v_object->ref_count;
355 /* Save "mounted from" info for mount point (NULL pad)*/
356 copyinstr( args.fspec, /* device name*/
357 mp->mnt_stat.f_mntfromname, /* save area*/
358 MNAMELEN - 1, /* max size*/
359 &size); /* real size*/
360 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
363 if ((err = ffs_mountfs(devvp, mp, M_MFSNODE)) != 0) {
364 mfsp->mfs_active = 0;
369 * Initialize FS stat information in mount struct; uses
370 * mp->mnt_stat.f_mntfromname.
372 * This code is common to root and non-root mounts
374 VFS_STATFS(mp, &mp->mnt_stat, cred);
378 error_2: /* error with devvp held*/
380 /* release devvp before failing*/
383 error_1: /* no state to back out*/
390 * Used to grab the process and keep it in the kernel to service
391 * memory filesystem I/O requests.
393 * Loop servicing I/O requests.
394 * Copy the requested data into or out of the memory filesystem
399 mfs_start(struct mount *mp, int flags)
401 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
402 struct mfsnode *mfsp = VTOMFS(vp);
406 thread_t td = curthread;
409 * We must prevent the system from trying to swap
410 * out or kill ( when swap space is low, see vm/pageout.c ) the
411 * process. A deadlock can occur if the process is swapped out,
412 * and the system can loop trying to kill the unkillable ( while
413 * references exist ) MFS process when swap space is low.
420 while (mfsp->mfs_active) {
423 while ((bio = bioq_first(&mfsp->bio_queue)) != NULL) {
424 bioq_remove(&mfsp->bio_queue, bio);
435 * If a non-ignored signal is received, try to unmount.
436 * If that fails, clear the signal (it has been "processed"),
437 * otherwise we will loop here, as tsleep will always return
441 * Note that dounmount() may fail if work was queued after
442 * we slept. We have to jump hoops here to make sure that we
443 * process any buffers after the sleep, before we dounmount()
447 if (dounmount(mp, 0) != 0) {
448 KKASSERT(td->td_proc);
449 sig = CURSIG(td->td_proc);
451 SIGDELSET(td->td_proc->p_siglist, sig);
454 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0))
455 gotsig++; /* try to unmount in next pass */
458 v_release_rdev(vp); /* hack because we do not implement CLOSE */
459 /* XXX destroy/release devvp */
464 * Get file system statistics.
467 mfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
471 error = ffs_statfs(mp, sbp, cred);
472 sbp->f_type = mp->mnt_vfc->vfc_typenum;
477 * Memory based filesystem initialization.
480 mfs_init(struct vfsconf *vfsp)
482 cdevsw_add(&mfs_cdevsw, 0, 0);