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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 1.28 2006/04/02 01:35:34 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>
55 #include <vm/vm_object.h>
56 #include <vm/vm_page.h>
57 #include <vm/vm_pager.h>
58 #include <vm/vnode_pager.h>
61 #include <sys/thread2.h>
63 #include <vfs/ufs/quota.h>
64 #include <vfs/ufs/inode.h>
65 #include <vfs/ufs/ufsmount.h>
66 #include <vfs/ufs/ufs_extern.h>
67 #include <vfs/ufs/fs.h>
68 #include <vfs/ufs/ffs_extern.h>
71 #include "mfs_extern.h"
73 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
76 extern struct vop_ops *mfs_vnode_vops;
78 static int mfs_mount (struct mount *mp,
79 char *path, caddr_t data, struct thread *td);
80 static int mfs_start (struct mount *mp, int flags, struct thread *td);
81 static int mfs_statfs (struct mount *mp, struct statfs *sbp,
83 static int mfs_init (struct vfsconf *);
87 d_strategy_t mfsstrategy;
89 #define MFS_CDEV_MAJOR 253
91 static struct cdevsw mfs_cdevsw = {
93 /* maj */ MFS_CDEV_MAJOR,
101 /* write */ physwrite,
105 /* strategy */ mfsstrategy,
111 * mfs vfs operations.
113 static struct vfsops mfs_vfsops = {
114 .vfs_mount = mfs_mount,
115 .vfs_start = mfs_start,
116 .vfs_unmount = ffs_unmount,
117 .vfs_root = ufs_root,
118 .vfs_quotactl = ufs_quotactl,
119 .vfs_statfs = mfs_statfs,
120 .vfs_sync = ffs_sync,
121 .vfs_vget = ffs_vget,
122 .vfs_fhtovp = ffs_fhtovp,
123 .vfs_checkexp = ufs_check_export,
124 .vfs_vptofh = ffs_vptofh,
128 VFS_SET(mfs_vfsops, mfs, 0);
131 * We allow the underlying MFS block device to be opened and read.
134 mfsopen(dev_t dev, int flags, int mode, struct thread *td)
144 mfsclose(dev_t dev, int flags, int mode, struct thread *td)
150 mfsstrategy(dev_t dev, struct bio *bio)
152 struct buf *bp = bio->bio_buf;
153 struct mfsnode *mfsp;
155 if ((mfsp = dev->si_drv1) != NULL) {
156 off_t boff = bio->bio_offset;
157 off_t eoff = boff + bp->b_bcount;
160 bp->b_error = EINVAL;
162 } else if (eoff <= mfsp->mfs_size) {
163 bioq_insert_tail(&mfsp->bio_queue, bio);
164 wakeup((caddr_t)mfsp);
165 } else if (boff < mfsp->mfs_size) {
166 bp->b_bcount = mfsp->mfs_size - boff;
167 bioq_insert_tail(&mfsp->bio_queue, bio);
168 wakeup((caddr_t)mfsp);
169 } else if (boff == mfsp->mfs_size) {
170 bp->b_resid = bp->b_bcount;
173 bp->b_error = EINVAL;
178 bp->b_flags |= B_ERROR;
186 * Called when mounting local physical media
190 * mp mount point structure
191 * path NULL (flag for root mount!!!)
194 * p process (user credentials check [statfs])
197 * mp mount point structure
198 * path path to mount point
199 * data pointer to argument struct in user space
200 * ndp mount point namei() return (used for
201 * credentials on reload), reused to look
203 * p process (user credentials check)
206 * !0 error number (errno.h)
211 * mount point is locked
213 * mount point is locked
216 * A NULL path can be used for a flag since the mount
217 * system call will fail with EFAULT in copyinstr in
218 * namei() if it is a genuine NULL from the user.
222 mfs_mount(struct mount *mp, char *path, caddr_t data, struct thread *td)
225 struct mfs_args args;
226 struct ufsmount *ump;
228 struct mfsnode *mfsp;
235 * Use NULL path to flag a root mount
240 * Mounting root file system
245 panic("mfs_mount: mount MFS as root: not configured!");
250 * Mounting non-root file system or updating a file system
254 /* copy in user arguments*/
255 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
259 * If updating, check whether changing from read-only to
260 * read/write; if there is no device name, that's all we do.
262 if (mp->mnt_flag & MNT_UPDATE) {
270 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
272 if (mp->mnt_flag & MNT_FORCE)
274 err = ffs_flushfiles(mp, flags, td);
278 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
279 /* XXX reopen the device vnode read-write */
282 /* if not updating name...*/
283 if (args.fspec == 0) {
285 * Process export requests. Jumping to "success"
286 * will return the vfs_export() error code.
288 err = vfs_export(mp, &ump->um_export, &args.export);
292 /* XXX MFS does not support name updating*/
296 * Do the MALLOC before the getnewvnode since doing so afterward
297 * might cause a bogus v_data pointer to get dereferenced
298 * elsewhere if MALLOC should block.
300 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
302 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops, &devvp, 0, 0);
304 FREE(mfsp, M_MFSNODE);
308 minnum = (curproc->p_pid & 0xFF) |
309 ((curproc->p_pid & ~0xFF) << 8);
311 devvp->v_type = VCHR;
312 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600,
313 "MFS%d", minnum >> 16);
314 /* It is not clear that these will get initialized otherwise */
315 dev->si_bsize_phys = DEV_BSIZE;
316 dev->si_iosize_max = DFLTPHYS;
318 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum));
319 devvp->v_data = mfsp;
320 mfsp->mfs_baseoff = args.base;
321 mfsp->mfs_size = args.size;
322 mfsp->mfs_vnode = devvp;
323 mfsp->mfs_dev = reference_dev(dev);
325 mfsp->mfs_active = 1;
326 bioq_init(&mfsp->bio_queue);
329 * Our 'block' device must be backed by a VM object. Theoretically
330 * we could use the anonymous memory VM object supplied by userland,
331 * but it would be somewhat of a complex task to deal with it
332 * that way since it would result in I/O requests which supply
333 * the VM pages from our own object.
335 * vnode_pager_alloc() is typically called when a VM object is
336 * being referenced externally. We have to undo the refs for
337 * the self reference between vnode and object.
339 vnode_pager_alloc(devvp, args.size, 0, 0);
341 --devvp->v_object->ref_count;
343 /* Save "mounted from" info for mount point (NULL pad)*/
344 copyinstr( args.fspec, /* device name*/
345 mp->mnt_stat.f_mntfromname, /* save area*/
346 MNAMELEN - 1, /* max size*/
347 &size); /* real size*/
348 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
351 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) {
352 mfsp->mfs_active = 0;
357 * Initialize FS stat information in mount struct; uses
358 * mp->mnt_stat.f_mntfromname.
360 * This code is common to root and non-root mounts
362 VFS_STATFS(mp, &mp->mnt_stat, td);
366 error_2: /* error with devvp held*/
368 /* release devvp before failing*/
371 error_1: /* no state to back out*/
378 * Used to grab the process and keep it in the kernel to service
379 * memory filesystem I/O requests.
381 * Loop servicing I/O requests.
382 * Copy the requested data into or out of the memory filesystem
387 mfs_start(struct mount *mp, int flags, struct thread *td)
389 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
390 struct mfsnode *mfsp = VTOMFS(vp);
396 * We must prevent the system from trying to swap
397 * out or kill ( when swap space is low, see vm/pageout.c ) the
398 * process. A deadlock can occur if the process is swapped out,
399 * and the system can loop trying to kill the unkillable ( while
400 * references exist ) MFS process when swap space is low.
405 while (mfsp->mfs_active) {
408 while ((bio = bioq_first(&mfsp->bio_queue)) != NULL) {
409 bioq_remove(&mfsp->bio_queue, bio);
420 * If a non-ignored signal is received, try to unmount.
421 * If that fails, clear the signal (it has been "processed"),
422 * otherwise we will loop here, as tsleep will always return
426 * Note that dounmount() may fail if work was queued after
427 * we slept. We have to jump hoops here to make sure that we
428 * process any buffers after the sleep, before we dounmount()
432 if (dounmount(mp, 0, td) != 0) {
433 KKASSERT(td->td_proc);
434 sig = CURSIG(td->td_proc);
436 SIGDELSET(td->td_proc->p_siglist, sig);
439 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0))
440 gotsig++; /* try to unmount in next pass */
443 v_release_rdev(vp); /* hack because we do not implement CLOSE */
444 /* XXX destroy/release devvp */
449 * Get file system statistics.
452 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
456 error = ffs_statfs(mp, sbp, td);
457 sbp->f_type = mp->mnt_vfc->vfc_typenum;
462 * Memory based filesystem initialization.
465 mfs_init(struct vfsconf *vfsp)
467 cdevsw_add(&mfs_cdevsw, 0, 0);