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SubjectRe: [PATCH V3 02/17] Squashfs: directory lookup operations
Hi Phillip.

One possible 'show-stopper' below and couple trivials.

On Mon, Jan 05, 2009 at 11:08:23AM +0000, Phillip Lougher (phillip@lougher.demon.co.uk) wrote:
> +static int get_dir_index_using_name(struct super_block *sb,
> + u64 *next_block, int *next_offset, u64 index_start,
> + int index_offset, int i_count, const char *name,
> + int len)
> +{
> + struct squashfs_sb_info *msblk = sb->s_fs_info;
> + int i, size, length = 0, err;
> + struct squashfs_dir_index *index;
> + char *str;
> +
> + TRACE("Entered get_dir_index_using_name, i_count %d\n", i_count);
> +
> + index = kmalloc(sizeof(*index) + SQUASHFS_NAME_LEN * 2 + 2, GFP_KERNEL);
> + if (index == NULL) {
> + ERROR("Failed to allocate squashfs_dir_index\n");
> + goto out;
> + }
> +
> + str = &index->name[SQUASHFS_NAME_LEN + 1];
> + strncpy(str, name, len);
> + str[len] = '\0';
> +
> + for (i = 0; i < i_count; i++) {
> + err = squashfs_read_metadata(sb, index, &index_start,
> + &index_offset, sizeof(*index));
> + if (err < 0)
> + break;
> +
> +

Double new line. Code-style purists will scream when see this.
This was a show-stopper.

> + size = le32_to_cpu(index->size) + 1;
> +
> + err = squashfs_read_metadata(sb, index->name, &index_start,
> + &index_offset, size);
> + if (err < 0)
> + break;
> +
> + index->name[size] = '\0';
> +
> + if (strcmp(index->name, str) > 0)
> + break;
> +
> + length = le32_to_cpu(index->index);
> + *next_block = le32_to_cpu(index->start_block) +
> + msblk->directory_table;
> + }
> +
> + *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE;
> + kfree(index);
> +
> +out:
> + /*
> + * Return index (f_pos) of the looked up metadata block. Translate
> + * from internal f_pos to external f_pos which is offset by 3 because
> + * we invent "." and ".." entries which are not actually stored in the
> + * directory.
> + */
> + return length + 3;
> +}
> +
> +

Another double new-line show-stopper.

> +static struct dentry *squashfs_lookup(struct inode *dir, struct dentry *dentry,
> + struct nameidata *nd)
> +{
> + const unsigned char *name = dentry->d_name.name;
> + int len = dentry->d_name.len;
> + struct inode *inode = NULL;
> + struct squashfs_sb_info *msblk = dir->i_sb->s_fs_info;
> + struct squashfs_dir_header dirh;
> + struct squashfs_dir_entry *dire;
> + u64 block = squashfs_i(dir)->start + msblk->directory_table;
> + int offset = squashfs_i(dir)->offset;
> + int err, length = 0, dir_count, size;
> +
> + TRACE("Entered squashfs_lookup [%llx:%x]\n", block, offset);
> +
> + dire = kmalloc(sizeof(*dire) + SQUASHFS_NAME_LEN + 1, GFP_KERNEL);
> + if (dire == NULL) {
> + ERROR("Failed to allocate squashfs_dir_entry\n");
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + if (len > SQUASHFS_NAME_LEN) {
> + err = -ENAMETOOLONG;
> + goto failed;
> + }
> +
> + length = get_dir_index_using_name(dir->i_sb, &block, &offset,
> + squashfs_i(dir)->dir_idx_start,
> + squashfs_i(dir)->dir_idx_offset,
> + squashfs_i(dir)->dir_idx_cnt, name, len);
> +

You do not check the return value here.
Plus dir entry allocation can be done after above len check.
This one is trivial.

--
Evgeniy Polyakov


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