static 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;
	unsigned short dev;
	unsigned char *mdata = NULL;
	int mdatalen = 0;
	unsigned int ivalid;
	uint32_t phys_ofs, alloclen;
	int ret;
	D1(printk(KERN_DEBUG "jffs2_setattr(): ino #%lu\n", inode->i_ino));
	ret = inode_change_ok(inode, iattr);
	if (ret)
		return ret;

	/* 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 */
		dev = old_encode_dev(inode->i_rdev);
		mdata = (char *)&dev;
		mdatalen = sizeof(dev);
		D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of kdev_t\n", mdatalen));
	} else if (S_ISLNK(inode->i_mode)) {
		mdatalen = f->metadata->size;
		mdata = kmalloc(f->metadata->size, GFP_USER);
		if (!mdata)
			return -ENOMEM;
		ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
		if (ret) {
			kfree(mdata);
			return ret;
		}
		D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of symlink target\n", 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, &phys_ofs, &alloclen,
				ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
	if (ret) {
		jffs2_free_raw_inode(ri);
		if (S_ISLNK(inode->i_mode & S_IFMT))
			 kfree(mdata);
		return ret;
	}
	down(&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)?iattr->ia_uid:inode->i_uid);
	ri->gid = cpu_to_je16((ivalid & ATTR_GID)?iattr->ia_gid:inode->i_gid);

	if (ivalid & ATTR_MODE)
		if (iattr->ia_mode & S_ISGID &&
		    !in_group_p(je16_to_cpu(ri->gid)) && !capable(CAP_FSETID))
			ri->mode = cpu_to_jemode(iattr->ia_mode & ~S_ISGID);
		else
			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);
	}
	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, phys_ofs, ALLOC_NORMAL);
	if (S_ISLNK(inode->i_mode))
		kfree(mdata);

	if (IS_ERR(new_metadata)) {
		jffs2_complete_reservation(c);
		jffs2_free_raw_inode(ri);
		up(&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);
	inode->i_uid = je16_to_cpu(ri->uid);
	inode->i_gid = 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;
		f->metadata = NULL;
	} else {
		f->metadata = new_metadata;
	}
	if (old_metadata) {
		jffs2_mark_node_obsolete(c, old_metadata->raw);
		jffs2_free_full_dnode(old_metadata);
	}
	jffs2_free_raw_inode(ri);

	up(&f->sem);
	jffs2_complete_reservation(c);

	/* We have to do the vmtruncate() without f->sem held, since
	   some pages may be locked and waiting for it in readpage().
	   We are protected from a simultaneous write() extending i_size
	   back past iattr->ia_size, because do_truncate() holds the
	   generic inode semaphore. */
	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
		vmtruncate(inode, iattr->ia_size);

	return 0;
}
Example #2
0
static int jffs2_prepare_write (struct file *filp, struct page *pg,
				unsigned start, unsigned end)
{
	struct inode *inode = pg->mapping->host;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
	int ret = 0;

	D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));

	if (pageofs > inode->i_size) {
		/* Make new hole frag from old EOF to new page */
		struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
		struct jffs2_raw_inode ri;
		struct jffs2_full_dnode *fn;
		uint32_t phys_ofs, alloc_len;

		D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
			  (unsigned int)inode->i_size, pageofs));

		ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len,
					ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
		if (ret)
			return ret;

		down(&f->sem);
		memset(&ri, 0, sizeof(ri));

		ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
		ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
		ri.totlen = cpu_to_je32(sizeof(ri));
		ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));

		ri.ino = cpu_to_je32(f->inocache->ino);
		ri.version = cpu_to_je32(++f->highest_version);
		ri.mode = cpu_to_jemode(inode->i_mode);
		ri.uid = cpu_to_je16(inode->i_uid);
		ri.gid = cpu_to_je16(inode->i_gid);
		ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
		ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
		ri.offset = cpu_to_je32(inode->i_size);
		ri.dsize = cpu_to_je32(pageofs - inode->i_size);
		ri.csize = cpu_to_je32(0);
		ri.compr = JFFS2_COMPR_ZERO;
		ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
		ri.data_crc = cpu_to_je32(0);

		fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);

		if (IS_ERR(fn)) {
			ret = PTR_ERR(fn);
			jffs2_complete_reservation(c);
			up(&f->sem);
			return ret;
		}
		ret = jffs2_add_full_dnode_to_inode(c, f, fn);
		if (f->metadata) {
			jffs2_mark_node_obsolete(c, f->metadata->raw);
			jffs2_free_full_dnode(f->metadata);
			f->metadata = NULL;
		}
		if (ret) {
			D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
			jffs2_mark_node_obsolete(c, fn->raw);
			jffs2_free_full_dnode(fn);
			jffs2_complete_reservation(c);
			up(&f->sem);
			return ret;
		}
		jffs2_complete_reservation(c);
		inode->i_size = pageofs;
		up(&f->sem);
	}

	/* Read in the page if it wasn't already present, unless it's a whole page */
	if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
		down(&f->sem);
		ret = jffs2_do_readpage_nolock(inode, pg);
		up(&f->sem);
	}
	D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
	return ret;
}
Example #3
0
File: file.c Project: 020gzh/linux
static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	struct page *pg;
	struct inode *inode = mapping->host;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	pgoff_t index = pos >> PAGE_SHIFT;
	uint32_t pageofs = index << PAGE_SHIFT;
	int ret = 0;

	pg = grab_cache_page_write_begin(mapping, index, flags);
	if (!pg)
		return -ENOMEM;
	*pagep = pg;

	jffs2_dbg(1, "%s()\n", __func__);

	if (pageofs > inode->i_size) {
		/* Make new hole frag from old EOF to new page */
		struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
		struct jffs2_raw_inode ri;
		struct jffs2_full_dnode *fn;
		uint32_t alloc_len;

		jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
			  (unsigned int)inode->i_size, pageofs);

		ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
					  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
		if (ret)
			goto out_page;

		mutex_lock(&f->sem);
		memset(&ri, 0, sizeof(ri));

		ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
		ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
		ri.totlen = cpu_to_je32(sizeof(ri));
		ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));

		ri.ino = cpu_to_je32(f->inocache->ino);
		ri.version = cpu_to_je32(++f->highest_version);
		ri.mode = cpu_to_jemode(inode->i_mode);
		ri.uid = cpu_to_je16(i_uid_read(inode));
		ri.gid = cpu_to_je16(i_gid_read(inode));
		ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
		ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
		ri.offset = cpu_to_je32(inode->i_size);
		ri.dsize = cpu_to_je32(pageofs - inode->i_size);
		ri.csize = cpu_to_je32(0);
		ri.compr = JFFS2_COMPR_ZERO;
		ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
		ri.data_crc = cpu_to_je32(0);

		fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);

		if (IS_ERR(fn)) {
			ret = PTR_ERR(fn);
			jffs2_complete_reservation(c);
			mutex_unlock(&f->sem);
			goto out_page;
		}
		ret = jffs2_add_full_dnode_to_inode(c, f, fn);
		if (f->metadata) {
			jffs2_mark_node_obsolete(c, f->metadata->raw);
			jffs2_free_full_dnode(f->metadata);
			f->metadata = NULL;
		}
		if (ret) {
			jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n",
				  ret);
			jffs2_mark_node_obsolete(c, fn->raw);
			jffs2_free_full_dnode(fn);
			jffs2_complete_reservation(c);
			mutex_unlock(&f->sem);
			goto out_page;
		}
		jffs2_complete_reservation(c);
		inode->i_size = pageofs;
		mutex_unlock(&f->sem);
	}

	/*
	 * Read in the page if it wasn't already present. Cannot optimize away
	 * the whole page write case until jffs2_write_end can handle the
	 * case of a short-copy.
	 */
	if (!PageUptodate(pg)) {
		mutex_lock(&f->sem);
		ret = jffs2_do_readpage_nolock(inode, pg);
		mutex_unlock(&f->sem);
		if (ret)
			goto out_page;
	}
	jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
	return ret;

out_page:
	unlock_page(pg);
	put_page(pg);
	return ret;
}