Ejemplo n.º 1
0
int
msdosfs_getattr(void *v)
{
	struct vop_getattr_args *ap = v;
	struct denode *dep = VTODE(ap->a_vp);
	struct msdosfsmount *pmp = dep->de_pmp;
	struct vattr *vap = ap->a_vap;
	struct timespec ts;
	uint32_t fileid;

	getnanotime(&ts);
	DETIMES(dep, &ts, &ts, &ts);
	vap->va_fsid = dep->de_dev;

	/*
	 * The following computation of the fileid must be the same as
	 * that used in msdosfs_readdir() to compute d_fileno. If not,
	 * pwd doesn't work.
	 *
	 * We now use the starting cluster number as the fileid/fileno.
	 * This works for both files and directories (including the root
	 * directory, on FAT32).  Even on FAT32, this will at most be a
	 * 28-bit number, as the high 4 bits of FAT32 cluster numbers
	 * are reserved.
	 *
	 * However, we do need to do something for 0-length files, which
	 * will not have a starting cluster number.
	 *
	 * These files cannot be directories, since (except for /, which
	 * is special-cased anyway) directories contain entries for . and
	 * .., so must have non-zero length.
	 *
	 * In this case, we just create a non-cryptographic hash of the
	 * original fileid calculation, and set the top bit.
	 *
	 * This algorithm has the benefit that all directories, and all
	 * non-zero-length files, will have fileids that are persistent
	 * across mounts and reboots, and that cannot collide (as long
	 * as the filesystem is not corrupt).  Zero-length files will
	 * have fileids that are persistent, but that may collide.  We
	 * will just have to live with that.
	 */
	fileid = dep->de_StartCluster;

	if (dep->de_Attributes & ATTR_DIRECTORY) {
		/* Special-case root */
		if (dep->de_StartCluster == MSDOSFSROOT)
			fileid = FAT32(pmp) ? pmp->pm_rootdirblk : 1;
	} else {
		if (dep->de_FileSize == 0) {
			uint32_t dirsperblk;
			uint64_t fileid64;

			dirsperblk = pmp->pm_BytesPerSec /
			    sizeof(struct direntry);

			fileid64 = (dep->de_dirclust == MSDOSFSROOT) ?
			    roottobn(pmp, 0) : cntobn(pmp, dep->de_dirclust);
			fileid64 *= dirsperblk;
			fileid64 += dep->de_diroffset / sizeof(struct direntry);

			fileid = fileidhash(fileid64);
		}
	}

	vap->va_fileid = fileid;
	vap->va_mode = (S_IXUSR|S_IXGRP|S_IXOTH) | (S_IRUSR|S_IRGRP|S_IROTH) |
	    ((dep->de_Attributes & ATTR_READONLY) ? 0 : (S_IWUSR|S_IWGRP|S_IWOTH));
	vap->va_mode &= dep->de_pmp->pm_mask;
	if (dep->de_Attributes & ATTR_DIRECTORY) {
		vap->va_mode |= S_IFDIR;
		if (pmp->pm_flags & MSDOSFSMNT_ALLOWDIRX) {
			vap->va_mode |= (vap->va_mode & S_IRUSR) ? S_IXUSR : 0;
			vap->va_mode |= (vap->va_mode & S_IRGRP) ? S_IXGRP : 0;
			vap->va_mode |= (vap->va_mode & S_IROTH) ? S_IXOTH : 0;
		}
	}
	vap->va_nlink = 1;
	vap->va_gid = dep->de_pmp->pm_gid;
	vap->va_uid = dep->de_pmp->pm_uid;
	vap->va_rdev = 0;
	vap->va_size = dep->de_FileSize;
	dos2unixtime(dep->de_MDate, dep->de_MTime, 0, &vap->va_mtime);
	if (dep->de_pmp->pm_flags & MSDOSFSMNT_LONGNAME) {
		dos2unixtime(dep->de_ADate, 0, 0, &vap->va_atime);
		dos2unixtime(dep->de_CDate, dep->de_CTime, dep->de_CTimeHundredth, &vap->va_ctime);
	} else {
		vap->va_atime = vap->va_mtime;
		vap->va_ctime = vap->va_mtime;
	}
	vap->va_flags = 0;
	if ((dep->de_Attributes & ATTR_ARCHIVE) == 0)
		vap->va_flags |= SF_ARCHIVED;
	vap->va_gen = 0;
	vap->va_blocksize = dep->de_pmp->pm_bpcluster;
	vap->va_bytes = (dep->de_FileSize + dep->de_pmp->pm_crbomask) &
	    			~(dep->de_pmp->pm_crbomask);
	vap->va_type = ap->a_vp->v_type;
	return (0);
}
Ejemplo n.º 2
0
int
msdosfs_filestat(kvm_t *kd, struct vnode *vp, struct vnstat *vn)
{
	struct denode denode;
	static struct dosmount *mounts;
	struct dosmount *mnt;
	u_long dirsperblk;
	int fileid;

	if (!kvm_read_all(kd, (unsigned long)VTODE(vp), &denode,
	    sizeof(denode))) {
		warnx("can't read denode at %p", (void *)VTODE(vp));
		return (1);
	}

	/*
	 * Find msdosfsmount structure for the vnode's filesystem. Needed
	 * for some filesystem parameters
	 */
	for (mnt = mounts; mnt; mnt = mnt->next)
		if (mnt->kptr == denode.de_pmp)
			break;

	if (!mnt) {
		if ((mnt = malloc(sizeof(struct dosmount))) == NULL) {
			warn("malloc()");
			return (1);
		}
		if (!kvm_read_all(kd, (unsigned long)denode.de_pmp,
		    &mnt->data, sizeof(mnt->data))) {
			free(mnt);
			    warnx("can't read mount info at %p",
			    (void *)denode.de_pmp);
			return (1);
		}
		mnt->next = mounts;
		mounts = mnt;
		mnt->kptr = denode.de_pmp;
	}

	vn->vn_fsid = dev2udev(kd, mnt->data.pm_dev);
	vn->vn_mode = 0555;
	vn->vn_mode |= denode.de_Attributes & ATTR_READONLY ? 0 : 0222;
	vn->vn_mode &= mnt->data.pm_mask;

	/* Distinguish directories and files. No "special" files in FAT. */
	vn->vn_mode |= denode.de_Attributes & ATTR_DIRECTORY ? S_IFDIR : S_IFREG;
	vn->vn_size = denode.de_FileSize;

	/*
	 * XXX -
	 * Culled from msdosfs_vnops.c. There appears to be a problem
	 * here, in that a directory has the same inode number as the first
	 * file in the directory. stat(2) suffers from this problem also, so
	 * I won't try to fix it here.
	 * 
	 * The following computation of the fileid must be the same as that
	 * used in msdosfs_readdir() to compute d_fileno. If not, pwd
	 * doesn't work.
	 */
	dirsperblk = mnt->data.pm_BytesPerSec / sizeof(struct direntry);
	if (denode.de_Attributes & ATTR_DIRECTORY) {
		fileid = cntobn(&mnt->data, denode.de_StartCluster)
		    * dirsperblk;
		if (denode.de_StartCluster == MSDOSFSROOT)
			fileid = 1;
	} else {
		fileid = cntobn(&mnt->data, denode.de_dirclust) * dirsperblk;
		if (denode.de_dirclust == MSDOSFSROOT)
			fileid = roottobn(&mnt->data, 0) * dirsperblk;
		fileid += denode.de_diroffset / sizeof(struct direntry);
	}

	vn->vn_fileid = fileid;
	return (0);
}
Ejemplo n.º 3
0
int
msdosfs_readdir(void *v)
{
	struct vop_readdir_args *ap = v;
	int error = 0;
	int diff;
	long n;
	int blsize;
	long on;
	long lost;
	long count;
	uint32_t dirsperblk;
	uint32_t cn, lbn;
	uint32_t fileno;
	long bias = 0;
	daddr64_t bn;
	struct buf *bp;
	struct denode *dep = VTODE(ap->a_vp);
	struct msdosfsmount *pmp = dep->de_pmp;
	struct direntry *dentp;
	struct dirent dirbuf;
	struct uio *uio = ap->a_uio;
	u_long *cookies = NULL;
	int ncookies = 0;
	off_t offset, wlast = -1;
	int chksum = -1;

#ifdef MSDOSFS_DEBUG
	printf("msdosfs_readdir(): vp %08x, uio %08x, cred %08x, eofflagp %08x\n",
	    ap->a_vp, uio, ap->a_cred, ap->a_eofflag);
#endif

	/*
	 * msdosfs_readdir() won't operate properly on regular files since
	 * it does i/o only with the filesystem vnode, and hence can
	 * retrieve the wrong block from the buffer cache for a plain file.
	 * So, fail attempts to readdir() on a plain file.
	 */
	if ((dep->de_Attributes & ATTR_DIRECTORY) == 0)
		return (ENOTDIR);

	/*
	 * To be safe, initialize dirbuf
	 */
	bzero(dirbuf.d_name, sizeof(dirbuf.d_name));

	/*
	 * If the user buffer is smaller than the size of one dos directory
	 * entry or the file offset is not a multiple of the size of a
	 * directory entry, then we fail the read.
	 */
	count = uio->uio_resid & ~(sizeof(struct direntry) - 1);
	offset = uio->uio_offset;
	if (count < sizeof(struct direntry) ||
	    (offset & (sizeof(struct direntry) - 1)))
		return (EINVAL);
	lost = uio->uio_resid - count;
	uio->uio_resid = count;

	if (ap->a_ncookies) {
		ncookies = uio->uio_resid / sizeof(struct direntry) + 3;
		cookies = malloc(ncookies * sizeof(u_long), M_TEMP, M_WAITOK);
		*ap->a_cookies = cookies;
		*ap->a_ncookies = ncookies;
	}

	dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);

	/*
	 * If they are reading from the root directory then, we simulate
	 * the . and .. entries since these don't exist in the root
	 * directory.  We also set the offset bias to make up for having to
	 * simulate these entries. By this I mean that at file offset 64 we
	 * read the first entry in the root directory that lives on disk.
	 */
	if (dep->de_StartCluster == MSDOSFSROOT
	    || (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)) {
#if 0
		printf("msdosfs_readdir(): going after . or .. in root dir, offset %d\n",
		    offset);
#endif
		bias = 2 * sizeof(struct direntry);
		if (offset < bias) {
			for (n = (int)offset / sizeof(struct direntry);
			     n < 2; n++) {
			        if (FAT32(pmp))
				        dirbuf.d_fileno = pmp->pm_rootdirblk;
				else
				        dirbuf.d_fileno = 1;
				dirbuf.d_type = DT_DIR;
				switch (n) {
				case 0:
					dirbuf.d_namlen = 1;
					strlcpy(dirbuf.d_name, ".",
					    sizeof dirbuf.d_name);
					break;
				case 1:
					dirbuf.d_namlen = 2;
					strlcpy(dirbuf.d_name, "..",
					    sizeof dirbuf.d_name);
					break;
				}
				dirbuf.d_reclen = DIRENT_SIZE(&dirbuf);
				if (uio->uio_resid < dirbuf.d_reclen)
					goto out;
				error = uiomove((caddr_t) &dirbuf,
						dirbuf.d_reclen, uio);
				if (error)
					goto out;
				offset += sizeof(struct direntry);
				if (cookies) {
					*cookies++ = offset;
					if (--ncookies <= 0)
						goto out;
				}
			}
		}
	}

	while (uio->uio_resid > 0) {
		lbn = de_cluster(pmp, offset - bias);
		on = (offset - bias) & pmp->pm_crbomask;
		n = min(pmp->pm_bpcluster - on, uio->uio_resid);
		diff = dep->de_FileSize - (offset - bias);
		if (diff <= 0)
			break;
		n = min(n, diff);
		if ((error = pcbmap(dep, lbn, &bn, &cn, &blsize)) != 0)
			break;
		error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
		if (error) {
			brelse(bp);
			return (error);
		}
		n = min(n, blsize - bp->b_resid);

		/*
		 * Convert from dos directory entries to fs-independent
		 * directory entries.
		 */
		for (dentp = (struct direntry *)(bp->b_data + on);
		     (char *)dentp < bp->b_data + on + n;
		     dentp++, offset += sizeof(struct direntry)) {
#if 0
			printf("rd: dentp %08x prev %08x crnt %08x deName %02x attr %02x\n",
			    dentp, prev, crnt, dentp->deName[0], dentp->deAttributes);
#endif
			/*
			 * If this is an unused entry, we can stop.
			 */
			if (dentp->deName[0] == SLOT_EMPTY) {
				brelse(bp);
				goto out;
			}
			/*
			 * Skip deleted entries.
			 */
			if (dentp->deName[0] == SLOT_DELETED) {
				chksum = -1;
				wlast = -1;
				continue;
			}

			/*
			 * Handle Win95 long directory entries
			 */
			if (dentp->deAttributes == ATTR_WIN95) {
				struct winentry *wep;
				if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
					continue;
				wep = (struct winentry *)dentp;
				chksum = win2unixfn(wep, &dirbuf, chksum);
				if (wep->weCnt & WIN_LAST)
					wlast = offset;
				continue;
			}

			/*
			 * Skip volume labels
			 */
			if (dentp->deAttributes & ATTR_VOLUME) {
				chksum = -1;
				wlast = -1;
				continue;
			}

			/*
			 * This computation of d_fileno must match
			 * the computation of va_fileid in
			 * msdosfs_getattr.
			 */
			fileno = getushort(dentp->deStartCluster);
			if (FAT32(pmp))
			    fileno |= getushort(dentp->deHighClust) << 16;

			if (dentp->deAttributes & ATTR_DIRECTORY) {
				/* Special-case root */
				if (fileno == MSDOSFSROOT)  {
					fileno = FAT32(pmp) ?
					    pmp->pm_rootdirblk : 1;
				}

				dirbuf.d_fileno = fileno;
				dirbuf.d_type = DT_DIR;
			} else {
				if (getulong(dentp->deFileSize) == 0) {
					uint64_t fileno64;

					fileno64 = (cn == MSDOSFSROOT) ?
					    roottobn(pmp, 0) : cntobn(pmp, cn);

					fileno64 *= dirsperblk;
					fileno64 += dentp -
					    (struct direntry *)bp->b_data;

					fileno = fileidhash(fileno64);
				}

				dirbuf.d_fileno = fileno;
				dirbuf.d_type = DT_REG;
			}

			if (chksum != winChksum(dentp->deName))
				dirbuf.d_namlen = dos2unixfn(dentp->deName,
				    (u_char *)dirbuf.d_name,
				    pmp->pm_flags & MSDOSFSMNT_SHORTNAME);
			else
				dirbuf.d_name[dirbuf.d_namlen] = 0;
			chksum = -1;
			dirbuf.d_reclen = DIRENT_SIZE(&dirbuf);
			if (uio->uio_resid < dirbuf.d_reclen) {
				brelse(bp);
				/* Remember long-name offset. */
				if (wlast != -1)
					offset = wlast;
				goto out;
			}
			wlast = -1;
			error = uiomove((caddr_t) &dirbuf,
					dirbuf.d_reclen, uio);
			if (error) {
				brelse(bp);
				goto out;
			}
			if (cookies) {
				*cookies++ = offset + sizeof(struct direntry);
				if (--ncookies <= 0) {
					brelse(bp);
					goto out;
				}
			}
		}
		brelse(bp);
	}

out:
	/* Subtract unused cookies */
	if (ap->a_ncookies)
		*ap->a_ncookies -= ncookies;

	uio->uio_offset = offset;
	uio->uio_resid += lost;
	if (dep->de_FileSize - (offset - bias) <= 0)
		*ap->a_eofflag = 1;
	else
		*ap->a_eofflag = 0;
	return (error);
}