fs/squashfs/namei.c

Source file repositories/reference/linux-study-clean/fs/squashfs/namei.c

File Facts

System
Linux kernel
Corpus path
fs/squashfs/namei.c
Extension
.c
Size
6843 bytes
Lines
233
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

while (dir_count--) {
			/*
			 * Read directory entry.
			 */
			err = squashfs_read_metadata(dir->i_sb, dire, &block,
					&offset, sizeof(*dire));
			if (err < 0)
				goto read_failure;

			size = le16_to_cpu(dire->size) + 1;

			/* size should never be larger than SQUASHFS_NAME_LEN */
			if (size > SQUASHFS_NAME_LEN)
				goto data_error;

			err = squashfs_read_metadata(dir->i_sb, dire->name,
					&block, &offset, size);
			if (err < 0)
				goto read_failure;

			length += sizeof(*dire) + size;

			if (name[0] < dire->name[0])
				goto exit_lookup;

			if (len == size && !strncmp(name, dire->name, len)) {
				unsigned int blk, off, ino_num;
				long long ino;
				blk = le32_to_cpu(dirh.start_block);
				off = le16_to_cpu(dire->offset);
				ino_num = le32_to_cpu(dirh.inode_number) +
					(short) le16_to_cpu(dire->inode_number);
				ino = SQUASHFS_MKINODE(blk, off);

				TRACE("calling squashfs_iget for directory "
					"entry %s, inode  %x:%x, %d\n", name,
					blk, off, ino_num);

				inode = squashfs_iget(dir->i_sb, ino, ino_num);
				goto exit_lookup;
			}
		}
	}

exit_lookup:
	kfree(dire);
	return d_splice_alias(inode, dentry);

data_error:
	err = -EIO;

read_failure:
	ERROR("Unable to read directory block [%llx:%x]\n",
		squashfs_i(dir)->start + msblk->directory_table,
		squashfs_i(dir)->offset);
failed:
	kfree(dire);
	return ERR_PTR(err);
}


const struct inode_operations squashfs_dir_inode_ops = {
	.lookup = squashfs_lookup,
	.listxattr = squashfs_listxattr
};

Annotation

Implementation Notes