示例#1
0
文件: fs.c 项目: mkrufky/linux
int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
{
	struct jffs2_full_dnode *old_metadata, *new_metadata;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	struct jffs2_raw_inode *ri;
	union jffs2_device_node dev;
	unsigned char *mdata = NULL;
	int mdatalen = 0;
	unsigned int ivalid;
	uint32_t alloclen;
	int ret;
	int alloc_type = ALLOC_NORMAL;

	jffs2_dbg(1, "%s(): ino #%lu\n", __func__, inode->i_ino);

	/* Special cases - we don't want more than one data node
	   for these types on the medium at any time. So setattr
	   must read the original data associated with the node
	   (i.e. the device numbers or the target name) and write
	   it out again with the appropriate data attached */
	if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
		/* For these, we don't actually need to read the old node */
		mdatalen = jffs2_encode_dev(&dev, inode->i_rdev);
		mdata = (char *)&dev;
		jffs2_dbg(1, "%s(): Writing %d bytes of kdev_t\n",
			  __func__, mdatalen);
	} else if (S_ISLNK(inode->i_mode)) {
		mutex_lock(&f->sem);
		mdatalen = f->metadata->size;
		mdata = kmalloc(f->metadata->size, GFP_USER);
		if (!mdata) {
			mutex_unlock(&f->sem);
			return -ENOMEM;
		}
		ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
		if (ret) {
			mutex_unlock(&f->sem);
			kfree(mdata);
			return ret;
		}
		mutex_unlock(&f->sem);
		jffs2_dbg(1, "%s(): Writing %d bytes of symlink target\n",
			  __func__, mdatalen);
	}

	ri = jffs2_alloc_raw_inode();
	if (!ri) {
		if (S_ISLNK(inode->i_mode))
			kfree(mdata);
		return -ENOMEM;
	}

	ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &alloclen,
				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
	if (ret) {
		jffs2_free_raw_inode(ri);
		if (S_ISLNK(inode->i_mode))
			 kfree(mdata);
		return ret;
	}
	mutex_lock(&f->sem);
	ivalid = iattr->ia_valid;

	ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
	ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen);
	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));

	ri->ino = cpu_to_je32(inode->i_ino);
	ri->version = cpu_to_je32(++f->highest_version);

	ri->uid = cpu_to_je16((ivalid & ATTR_UID)?
		from_kuid(&init_user_ns, iattr->ia_uid):i_uid_read(inode));
	ri->gid = cpu_to_je16((ivalid & ATTR_GID)?
		from_kgid(&init_user_ns, iattr->ia_gid):i_gid_read(inode));

	if (ivalid & ATTR_MODE)
		ri->mode = cpu_to_jemode(iattr->ia_mode);
	else
		ri->mode = cpu_to_jemode(inode->i_mode);


	ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size);
	ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode->i_atime));
	ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode->i_mtime));
	ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode->i_ctime));

	ri->offset = cpu_to_je32(0);
	ri->csize = ri->dsize = cpu_to_je32(mdatalen);
	ri->compr = JFFS2_COMPR_NONE;
	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
		/* It's an extension. Make it a hole node */
		ri->compr = JFFS2_COMPR_ZERO;
		ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size);
		ri->offset = cpu_to_je32(inode->i_size);
	} else if (ivalid & ATTR_SIZE && !iattr->ia_size) {
		/* For truncate-to-zero, treat it as deletion because
		   it'll always be obsoleting all previous nodes */
		alloc_type = ALLOC_DELETION;
	}
	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
	if (mdatalen)
		ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
	else
		ri->data_crc = cpu_to_je32(0);

	new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, alloc_type);
	if (S_ISLNK(inode->i_mode))
		kfree(mdata);

	if (IS_ERR(new_metadata)) {
		jffs2_complete_reservation(c);
		jffs2_free_raw_inode(ri);
		mutex_unlock(&f->sem);
		return PTR_ERR(new_metadata);
	}
	/* It worked. Update the inode */
	inode->i_atime = ITIME(je32_to_cpu(ri->atime));
	inode->i_ctime = ITIME(je32_to_cpu(ri->ctime));
	inode->i_mtime = ITIME(je32_to_cpu(ri->mtime));
	inode->i_mode = jemode_to_cpu(ri->mode);
	i_uid_write(inode, je16_to_cpu(ri->uid));
	i_gid_write(inode, je16_to_cpu(ri->gid));


	old_metadata = f->metadata;

	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
		jffs2_truncate_fragtree (c, &f->fragtree, iattr->ia_size);

	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
		jffs2_add_full_dnode_to_inode(c, f, new_metadata);
		inode->i_size = iattr->ia_size;
		inode->i_blocks = (inode->i_size + 511) >> 9;
		f->metadata = NULL;
	} else {
示例#2
0
static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, dev_t rdev)
{
	struct jffs2_inode_info *f, *dir_f;
	struct jffs2_sb_info *c;
	struct inode *inode;
	struct jffs2_raw_inode *ri;
	struct jffs2_raw_dirent *rd;
	struct jffs2_full_dnode *fn;
	struct jffs2_full_dirent *fd;
	int namelen;
	union jffs2_device_node dev;
	int devlen = 0;
	uint32_t alloclen;
	int ret;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	ri = jffs2_alloc_raw_inode();
	if (!ri)
		return -ENOMEM;

	c = JFFS2_SB_INFO(dir_i->i_sb);

	if (S_ISBLK(mode) || S_ISCHR(mode))
		devlen = jffs2_encode_dev(&dev, rdev);

	/* Try to reserve enough space for both node and dirent.
	 * Just the node will do for now, though
	 */
	namelen = dentry->d_name.len;
	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);

	if (ret) {
		jffs2_free_raw_inode(ri);
		return ret;
	}

	inode = jffs2_new_inode(dir_i, mode, ri);

	if (IS_ERR(inode)) {
		jffs2_free_raw_inode(ri);
		jffs2_complete_reservation(c);
		return PTR_ERR(inode);
	}
	inode->i_op = &jffs2_file_inode_operations;
	init_special_inode(inode, inode->i_mode, rdev);

	f = JFFS2_INODE_INFO(inode);

	ri->dsize = ri->csize = cpu_to_je32(devlen);
	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));

	ri->compr = JFFS2_COMPR_NONE;
	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));

	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);

	jffs2_free_raw_inode(ri);

	if (IS_ERR(fn)) {
		/* Eeek. Wave bye bye */
		mutex_unlock(&f->sem);
		jffs2_complete_reservation(c);
		ret = PTR_ERR(fn);
		goto fail;
	}
	/* No data here. Only a metadata node, which will be
	   obsoleted by the first data write
	*/
	f->metadata = fn;
	mutex_unlock(&f->sem);

	jffs2_complete_reservation(c);

	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
	if (ret)
		goto fail;

	ret = jffs2_init_acl_post(inode);
	if (ret)
		goto fail;

	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
	if (ret)
		goto fail;

	rd = jffs2_alloc_raw_dirent();
	if (!rd) {
		/* Argh. Now we treat it like a normal delete */
		jffs2_complete_reservation(c);
		ret = -ENOMEM;
		goto fail;
	}

	dir_f = JFFS2_INODE_INFO(dir_i);
	mutex_lock(&dir_f->sem);

	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));

	rd->pino = cpu_to_je32(dir_i->i_ino);
	rd->version = cpu_to_je32(++dir_f->highest_version);
	rd->ino = cpu_to_je32(inode->i_ino);
	rd->mctime = cpu_to_je32(get_seconds());
	rd->nsize = namelen;

	/* XXX: This is ugly. */
	rd->type = (mode & S_IFMT) >> 12;

	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));

	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);

	if (IS_ERR(fd)) {
		/* dirent failed to write. Delete the inode normally
		   as if it were the final unlink() */
		jffs2_complete_reservation(c);
		jffs2_free_raw_dirent(rd);
		mutex_unlock(&dir_f->sem);
		ret = PTR_ERR(fd);
		goto fail;
	}

	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));

	jffs2_free_raw_dirent(rd);

	/* Link the fd into the inode's list, obsoleting an old
	   one if necessary. */
	jffs2_add_fd_to_list(c, fd, &dir_f->dents);

	mutex_unlock(&dir_f->sem);
	jffs2_complete_reservation(c);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	return 0;

 fail:
	iget_failed(inode);
	return ret;
}