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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 1.14 2004/05/13 23:49:26 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>
55 #include <vfs/ufs/quota.h>
56 #include <vfs/ufs/inode.h>
57 #include <vfs/ufs/ufsmount.h>
58 #include <vfs/ufs/ufs_extern.h>
59 #include <vfs/ufs/fs.h>
60 #include <vfs/ufs/ffs_extern.h>
63 #include "mfs_extern.h"
65 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
68 static int mfs_minor; /* used for building internal dev_t */
70 extern vop_t **mfs_vnodeop_p;
72 static int mfs_mount (struct mount *mp,
73 char *path, caddr_t data, struct nameidata *ndp,
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 *);
80 #define MFS_CDEV_MAJOR 253
82 static struct cdevsw mfs_cdevsw = {
84 /* maj */ MFS_CDEV_MAJOR,
92 /* write */ physwrite,
96 /* strategy */ nostrategy,
102 * mfs vfs operations.
104 static struct vfsops mfs_vfsops = {
121 VFS_SET(mfs_vfsops, mfs, 0);
127 * Called when mounting local physical media
131 * mp mount point structure
132 * path NULL (flag for root mount!!!)
135 * p process (user credentials check [statfs])
138 * mp mount point structure
139 * path path to mount point
140 * data pointer to argument struct in user space
141 * ndp mount point namei() return (used for
142 * credentials on reload), reused to look
144 * p process (user credentials check)
147 * !0 error number (errno.h)
152 * mount point is locked
154 * mount point is locked
157 * A NULL path can be used for a flag since the mount
158 * system call will fail with EFAULT in copyinstr in
159 * namei() if it is a genuine NULL from the user.
163 mfs_mount(struct mount *mp, char *path, caddr_t data, struct nameidata *ndp,
167 struct mfs_args args;
168 struct ufsmount *ump;
170 struct mfsnode *mfsp;
176 * Use NULL path to flag a root mount
181 * Mounting root file system
186 panic("mfs_mount: mount MFS as root: not configured!");
191 * Mounting non-root file system or updating a file system
195 /* copy in user arguments*/
196 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
200 * If updating, check whether changing from read-only to
201 * read/write; if there is no device name, that's all we do.
203 if (mp->mnt_flag & MNT_UPDATE) {
211 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
213 if (mp->mnt_flag & MNT_FORCE)
215 err = ffs_flushfiles(mp, flags, td);
219 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR))
221 /* if not updating name...*/
222 if (args.fspec == 0) {
224 * Process export requests. Jumping to "success"
225 * will return the vfs_export() error code.
227 err = vfs_export(mp, &ump->um_export, &args.export);
231 /* XXX MFS does not support name updating*/
235 * Do the MALLOC before the getnewvnode since doing so afterward
236 * might cause a bogus v_data pointer to get dereferenced
237 * elsewhere if MALLOC should block.
239 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
241 err = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp);
243 FREE(mfsp, M_MFSNODE);
246 devvp->v_type = VCHR;
247 dev = make_dev(&mfs_cdevsw, mfs_minor, 0, 0, 0, "MFS%d", mfs_minor);
248 /* It is not clear that these will get initialized otherwise */
249 dev->si_bsize_phys = DEV_BSIZE;
250 dev->si_iosize_max = DFLTPHYS;
251 addaliasu(devvp, makeudev(253, mfs_minor++));
252 devvp->v_data = mfsp;
253 mfsp->mfs_baseoff = args.base;
254 mfsp->mfs_size = args.size;
255 mfsp->mfs_vnode = devvp;
257 mfsp->mfs_active = 1;
258 bufq_init(&mfsp->buf_queue);
261 * Since this is a new mount, we want the names for
262 * the device and the mount point copied in. If an
263 * error occurs, the mountpoint is discarded by the
266 /* Save "last mounted on" info for mount point (NULL pad)*/
267 copyinstr( path, /* mount point*/
268 mp->mnt_stat.f_mntonname, /* save area*/
269 MNAMELEN - 1, /* max size*/
270 &size); /* real size*/
271 bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
273 /* Save "mounted from" info for mount point (NULL pad)*/
274 copyinstr( args.fspec, /* device name*/
275 mp->mnt_stat.f_mntfromname, /* save area*/
276 MNAMELEN - 1, /* max size*/
277 &size); /* real size*/
278 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
280 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) {
281 mfsp->mfs_active = 0;
286 * Initialize FS stat information in mount struct; uses both
287 * mp->mnt_stat.f_mntonname and mp->mnt_stat.f_mntfromname
289 * This code is common to root and non-root mounts
291 (void) VFS_STATFS(mp, &mp->mnt_stat, td);
295 error_2: /* error with devvp held*/
297 /* release devvp before failing*/
300 error_1: /* no state to back out*/
307 * Used to grab the process and keep it in the kernel to service
308 * memory filesystem I/O requests.
310 * Loop servicing I/O requests.
311 * Copy the requested data into or out of the memory filesystem
316 mfs_start(struct mount *mp, int flags, struct thread *td)
318 struct vnode *vp = VFSTOUFS(mp)->um_devvp;
319 struct mfsnode *mfsp = VTOMFS(vp);
324 * We must prevent the system from trying to swap
325 * out or kill ( when swap space is low, see vm/pageout.c ) the
326 * process. A deadlock can occur if the process is swapped out,
327 * and the system can loop trying to kill the unkillable ( while
328 * references exist ) MFS process when swap space is low.
333 while (mfsp->mfs_active) {
338 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) {
339 bufq_remove(&mfsp->buf_queue, bp);
349 * If a non-ignored signal is received, try to unmount.
350 * If that fails, clear the signal (it has been "processed"),
351 * otherwise we will loop here, as tsleep will always return
355 * Note that dounmount() may fail if work was queued after
356 * we slept. We have to jump hoops here to make sure that we
357 * process any buffers after the sleep, before we dounmount()
361 if (dounmount(mp, 0, td) != 0) {
362 KKASSERT(td->td_proc);
363 sig = CURSIG(td->td_proc);
365 SIGDELSET(td->td_proc->p_siglist, sig);
368 else if (tsleep((caddr_t)vp, PCATCH, "mfsidl", 0))
369 gotsig++; /* try to unmount in next pass */
376 * Get file system statistics.
379 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
383 error = ffs_statfs(mp, sbp, td);
384 sbp->f_type = mp->mnt_vfc->vfc_typenum;
389 * Memory based filesystem initialization.
392 mfs_init(struct vfsconf *vfsp)
394 cdevsw_add(&mfs_cdevsw);