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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 1.27 2006/04/01 20:46:53 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 <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(dev_t dev, struct bio *bio)
147 struct buf *bp = bio->bio_buf;
148 struct mfsnode *mfsp;
150 if ((mfsp = dev->si_drv1) != NULL) {
151 off_t boff = bio->bio_offset;
152 off_t eoff = boff + bp->b_bcount;
155 bp->b_error = EINVAL;
157 } else if (eoff <= mfsp->mfs_size) {
158 bioq_insert_tail(&mfsp->bio_queue, bio);
159 wakeup((caddr_t)mfsp);
160 } else if (boff < mfsp->mfs_size) {
161 bp->b_bcount = mfsp->mfs_size - boff;
162 bioq_insert_tail(&mfsp->bio_queue, bio);
163 wakeup((caddr_t)mfsp);
164 } else if (boff == mfsp->mfs_size) {
165 bp->b_resid = bp->b_bcount;
168 bp->b_error = EINVAL;
173 bp->b_flags |= B_ERROR;
181 * Called when mounting local physical media
185 * mp mount point structure
186 * path NULL (flag for root mount!!!)
189 * p process (user credentials check [statfs])
192 * mp mount point structure
193 * path path to mount point
194 * data pointer to argument struct in user space
195 * ndp mount point namei() return (used for
196 * credentials on reload), reused to look
198 * p process (user credentials check)
201 * !0 error number (errno.h)
206 * mount point is locked
208 * mount point is locked
211 * A NULL path can be used for a flag since the mount
212 * system call will fail with EFAULT in copyinstr in
213 * namei() if it is a genuine NULL from the user.
217 mfs_mount(struct mount *mp, char *path, caddr_t data, struct thread *td)
220 struct mfs_args args;
221 struct ufsmount *ump;
223 struct mfsnode *mfsp;
230 * Use NULL path to flag a root mount
235 * Mounting root file system
240 panic("mfs_mount: mount MFS as root: not configured!");
245 * Mounting non-root file system or updating a file system
249 /* copy in user arguments*/
250 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
254 * If updating, check whether changing from read-only to
255 * read/write; if there is no device name, that's all we do.
257 if (mp->mnt_flag & MNT_UPDATE) {
265 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
267 if (mp->mnt_flag & MNT_FORCE)
269 err = ffs_flushfiles(mp, flags, td);
273 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
274 /* XXX reopen the device vnode read-write */
277 /* if not updating name...*/
278 if (args.fspec == 0) {
280 * Process export requests. Jumping to "success"
281 * will return the vfs_export() error code.
283 err = vfs_export(mp, &ump->um_export, &args.export);
287 /* XXX MFS does not support name updating*/
291 * Do the MALLOC before the getnewvnode since doing so afterward
292 * might cause a bogus v_data pointer to get dereferenced
293 * elsewhere if MALLOC should block.
295 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
297 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops, &devvp, 0, 0);
299 FREE(mfsp, M_MFSNODE);
303 minnum = (curproc->p_pid & 0xFF) |
304 ((curproc->p_pid & ~0xFF) << 8);
306 devvp->v_type = VCHR;
307 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600,
308 "MFS%d", minnum >> 16);
309 /* It is not clear that these will get initialized otherwise */
310 dev->si_bsize_phys = DEV_BSIZE;
311 dev->si_iosize_max = DFLTPHYS;
313 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum));
314 devvp->v_data = mfsp;
315 mfsp->mfs_baseoff = args.base;
316 mfsp->mfs_size = args.size;
317 mfsp->mfs_vnode = devvp;
318 mfsp->mfs_dev = reference_dev(dev);
320 mfsp->mfs_active = 1;
321 bioq_init(&mfsp->bio_queue);
323 /* Save "mounted from" info for mount point (NULL pad)*/
324 copyinstr( args.fspec, /* device name*/
325 mp->mnt_stat.f_mntfromname, /* save area*/
326 MNAMELEN - 1, /* max size*/
327 &size); /* real size*/
328 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
331 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) {
332 mfsp->mfs_active = 0;
337 * Initialize FS stat information in mount struct; uses
338 * mp->mnt_stat.f_mntfromname.
340 * This code is common to root and non-root mounts
342 VFS_STATFS(mp, &mp->mnt_stat, td);
346 error_2: /* error with devvp held*/
348 /* release devvp before failing*/
351 error_1: /* no state to back out*/
358 * Used to grab the process and keep it in the kernel to service
359 * memory filesystem I/O requests.
361 * Loop servicing I/O requests.
362 * Copy the requested data into or out of the memory filesystem
367 mfs_start(struct mount *mp, int flags, struct thread *td)
369 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
370 struct mfsnode *mfsp = VTOMFS(vp);
376 * We must prevent the system from trying to swap
377 * out or kill ( when swap space is low, see vm/pageout.c ) the
378 * process. A deadlock can occur if the process is swapped out,
379 * and the system can loop trying to kill the unkillable ( while
380 * references exist ) MFS process when swap space is low.
385 while (mfsp->mfs_active) {
388 while ((bio = bioq_first(&mfsp->bio_queue)) != NULL) {
389 bioq_remove(&mfsp->bio_queue, bio);
400 * If a non-ignored signal is received, try to unmount.
401 * If that fails, clear the signal (it has been "processed"),
402 * otherwise we will loop here, as tsleep will always return
406 * Note that dounmount() may fail if work was queued after
407 * we slept. We have to jump hoops here to make sure that we
408 * process any buffers after the sleep, before we dounmount()
412 if (dounmount(mp, 0, td) != 0) {
413 KKASSERT(td->td_proc);
414 sig = CURSIG(td->td_proc);
416 SIGDELSET(td->td_proc->p_siglist, sig);
419 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0))
420 gotsig++; /* try to unmount in next pass */
423 v_release_rdev(vp); /* hack because we do not implement CLOSE */
424 /* XXX destroy/release devvp */
429 * Get file system statistics.
432 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
436 error = ffs_statfs(mp, sbp, td);
437 sbp->f_type = mp->mnt_vfc->vfc_typenum;
442 * Memory based filesystem initialization.
445 mfs_init(struct vfsconf *vfsp)
447 cdevsw_add(&mfs_cdevsw, 0, 0);