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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 1.40 2007/05/09 00:53:35 dillon Exp $
39 #include <sys/param.h>
40 #include <sys/systm.h>
42 #include <sys/device.h>
43 #include <sys/kernel.h>
46 #include <sys/mount.h>
47 #include <sys/signalvar.h>
48 #include <sys/signal2.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");
75 extern struct vop_ops
*mfs_vnode_vops_p
;
77 static int mfs_mount (struct mount
*mp
,
78 char *path
, caddr_t data
, struct ucred
*td
);
79 static int mfs_start (struct mount
*mp
, int flags
);
80 static int mfs_statfs (struct mount
*mp
, struct statfs
*sbp
,
82 static int mfs_init (struct vfsconf
*);
86 d_strategy_t mfsstrategy
;
88 static struct dev_ops mfs_ops
= {
89 { "MFS", -1, D_DISK
},
94 .d_strategy
= mfsstrategy
,
100 static struct vfsops mfs_vfsops
= {
101 .vfs_mount
= mfs_mount
,
102 .vfs_start
= mfs_start
,
103 .vfs_unmount
= ffs_unmount
,
104 .vfs_root
= ufs_root
,
105 .vfs_quotactl
= ufs_quotactl
,
106 .vfs_statfs
= mfs_statfs
,
107 .vfs_sync
= ffs_sync
,
108 .vfs_vget
= ffs_vget
,
109 .vfs_fhtovp
= ffs_fhtovp
,
110 .vfs_checkexp
= ufs_check_export
,
111 .vfs_vptofh
= ffs_vptofh
,
115 VFS_SET(mfs_vfsops
, mfs
, 0);
118 * We allow the underlying MFS block device to be opened and read.
121 mfsopen(struct dev_open_args
*ap
)
123 cdev_t dev
= ap
->a_head
.a_dev
;
125 if (ap
->a_oflags
& FWRITE
)
133 mfsclose(struct dev_close_args
*ap
)
139 mfsstrategy(struct dev_strategy_args
*ap
)
141 cdev_t dev
= ap
->a_head
.a_dev
;
142 struct bio
*bio
= ap
->a_bio
;
143 struct buf
*bp
= bio
->bio_buf
;
144 off_t boff
= bio
->bio_offset
;
145 off_t eoff
= boff
+ bp
->b_bcount
;
146 struct mfsnode
*mfsp
;
148 if ((mfsp
= dev
->si_drv1
) == NULL
) {
154 if (eoff
> mfsp
->mfs_size
) {
155 if (boff
> mfsp
->mfs_size
|| (bp
->b_flags
& B_BNOCLIP
))
158 * Return EOF by completing the I/O with 0 bytes transfered.
159 * Set B_INVAL to indicate that any data in the buffer is not
162 if (boff
== mfsp
->mfs_size
) {
163 bp
->b_resid
= bp
->b_bcount
;
164 bp
->b_flags
|= B_INVAL
;
167 bp
->b_bcount
= mfsp
->mfs_size
- boff
;
173 bioq_insert_tail(&mfsp
->bio_queue
, bio
);
174 wakeup((caddr_t
)mfsp
);
178 * Failure conditions on bio
181 bp
->b_error
= EINVAL
;
183 bp
->b_flags
|= B_ERROR
| B_INVAL
;
192 * Called when mounting local physical media
196 * mp mount point structure
197 * path NULL (flag for root mount!!!)
200 * p process (user credentials check [statfs])
203 * mp mount point structure
204 * path path to mount point
205 * data pointer to argument struct in user space
206 * ndp mount point namei() return (used for
207 * credentials on reload), reused to look
209 * p process (user credentials check)
212 * !0 error number (errno.h)
217 * mount point is locked
219 * mount point is locked
222 * A NULL path can be used for a flag since the mount
223 * system call will fail with EFAULT in copyinstr in
224 * namei() if it is a genuine NULL from the user.
228 mfs_mount(struct mount
*mp
, char *path
, caddr_t data
, struct ucred
*cred
)
231 struct mfs_args args
;
232 struct ufsmount
*ump
;
234 struct mfsnode
*mfsp
;
241 * Use NULL path to flag a root mount
246 * Mounting root file system
251 panic("mfs_mount: mount MFS as root: not configured!");
256 * Mounting non-root file system or updating a file system
260 /* copy in user arguments*/
261 if ((err
= copyin(data
, (caddr_t
)&args
, sizeof (struct mfs_args
))) != 0)
265 * If updating, check whether changing from read-only to
266 * read/write; if there is no device name, that's all we do.
268 if (mp
->mnt_flag
& MNT_UPDATE
) {
276 if (fs
->fs_ronly
== 0 && (mp
->mnt_flag
& MNT_RDONLY
)) {
278 if (mp
->mnt_flag
& MNT_FORCE
)
280 err
= ffs_flushfiles(mp
, flags
);
284 if (fs
->fs_ronly
&& (mp
->mnt_kern_flag
& MNTK_WANTRDWR
)) {
285 /* XXX reopen the device vnode read-write */
288 /* if not updating name...*/
289 if (args
.fspec
== 0) {
291 * Process export requests. Jumping to "success"
292 * will return the vfs_export() error code.
294 err
= vfs_export(mp
, &ump
->um_export
, &args
.export
);
298 /* XXX MFS does not support name updating*/
302 * Do the MALLOC before the getnewvnode since doing so afterward
303 * might cause a bogus v_data pointer to get dereferenced
304 * elsewhere if MALLOC should block.
306 MALLOC(mfsp
, struct mfsnode
*, sizeof *mfsp
, M_MFSNODE
, M_WAITOK
);
308 err
= getspecialvnode(VT_MFS
, NULL
, &mfs_vnode_vops_p
, &devvp
, 0, 0);
310 FREE(mfsp
, M_MFSNODE
);
314 minnum
= (curproc
->p_pid
& 0xFF) |
315 ((curproc
->p_pid
& ~0xFF) << 8);
317 devvp
->v_type
= VCHR
;
318 dev
= make_dev(&mfs_ops
, minnum
, UID_ROOT
, GID_WHEEL
, 0600,
319 "MFS%d", minnum
>> 16);
320 /* It is not clear that these will get initialized otherwise */
321 dev
->si_bsize_phys
= DEV_BSIZE
;
322 dev
->si_iosize_max
= DFLTPHYS
;
324 addaliasu(devvp
, mfs_ops
.head
.maj
, minnum
);
325 devvp
->v_data
= mfsp
;
326 mfsp
->mfs_baseoff
= args
.base
;
327 mfsp
->mfs_size
= args
.size
;
328 mfsp
->mfs_vnode
= devvp
;
329 mfsp
->mfs_dev
= reference_dev(dev
);
330 mfsp
->mfs_td
= curthread
;
331 mfsp
->mfs_active
= 1;
332 bioq_init(&mfsp
->bio_queue
);
335 * Our 'block' device must be backed by a VM object. Theoretically
336 * we could use the anonymous memory VM object supplied by userland,
337 * but it would be somewhat of a complex task to deal with it
338 * that way since it would result in I/O requests which supply
339 * the VM pages from our own object.
341 * vnode_pager_alloc() is typically called when a VM object is
342 * being referenced externally. We have to undo the refs for
343 * the self reference between vnode and object.
345 vnode_pager_alloc(devvp
, args
.size
, 0, 0);
347 --devvp
->v_object
->ref_count
;
349 /* Save "mounted from" info for mount point (NULL pad)*/
350 copyinstr( args
.fspec
, /* device name*/
351 mp
->mnt_stat
.f_mntfromname
, /* save area*/
352 MNAMELEN
- 1, /* max size*/
353 &size
); /* real size*/
354 bzero( mp
->mnt_stat
.f_mntfromname
+ size
, MNAMELEN
- size
);
357 if ((err
= ffs_mountfs(devvp
, mp
, M_MFSNODE
)) != 0) {
358 mfsp
->mfs_active
= 0;
363 * Initialize FS stat information in mount struct; uses
364 * mp->mnt_stat.f_mntfromname.
366 * This code is common to root and non-root mounts
368 VFS_STATFS(mp
, &mp
->mnt_stat
, cred
);
372 error_2
: /* error with devvp held*/
374 /* release devvp before failing*/
377 error_1
: /* no state to back out*/
384 * Used to grab the process and keep it in the kernel to service
385 * memory filesystem I/O requests.
387 * Loop servicing I/O requests.
388 * Copy the requested data into or out of the memory filesystem
393 mfs_start(struct mount
*mp
, int flags
)
395 struct vnode
*vp
= VFSTOUFS(mp
)->um_devvp
;
396 struct mfsnode
*mfsp
= VTOMFS(vp
);
400 thread_t td
= curthread
;
403 * We must prevent the system from trying to swap
404 * out or kill ( when swap space is low, see vm/pageout.c ) the
405 * process. A deadlock can occur if the process is swapped out,
406 * and the system can loop trying to kill the unkillable ( while
407 * references exist ) MFS process when swap space is low.
414 while (mfsp
->mfs_active
) {
417 while ((bio
= bioq_first(&mfsp
->bio_queue
)) != NULL
) {
418 bioq_remove(&mfsp
->bio_queue
, bio
);
429 * If a non-ignored signal is received, try to unmount.
430 * If that fails, clear the signal (it has been "processed"),
431 * otherwise we will loop here, as tsleep will always return
435 * Note that dounmount() may fail if work was queued after
436 * we slept. We have to jump hoops here to make sure that we
437 * process any buffers after the sleep, before we dounmount()
441 if (dounmount(mp
, 0) != 0) {
442 KKASSERT(td
->td_proc
);
443 sig
= CURSIG(td
->td_lwp
);
445 lwp_delsig(td
->td_lwp
, sig
);
448 else if (tsleep((caddr_t
)mfsp
, PCATCH
, "mfsidl", 0))
449 gotsig
++; /* try to unmount in next pass */
452 v_release_rdev(vp
); /* hack because we do not implement CLOSE */
453 /* XXX destroy/release devvp */
458 * Get file system statistics.
461 mfs_statfs(struct mount
*mp
, struct statfs
*sbp
, struct ucred
*cred
)
465 error
= ffs_statfs(mp
, sbp
, cred
);
466 sbp
->f_type
= mp
->mnt_vfc
->vfc_typenum
;
471 * Memory based filesystem initialization.
474 mfs_init(struct vfsconf
*vfsp
)
476 dev_ops_add(&mfs_ops
, 0, 0);