staging: erofs: harden inode lookup for 32-bit platforms (2abd7814) · Commits · 戴 / test

drivers/staging/erofs/inode.c

+36 −1

Original line number	Diff line number	Diff line
		@@ -232,10 +232,45 @@ out_unlock:
		return err;
		}

		/*
		* erofs nid is 64bits, but i_ino is 'unsigned long', therefore
		* we should do more for 32-bit platform to find the right inode.
		*/
		#if BITS_PER_LONG == 32
		static int erofs_ilookup_test_actor(struct inode inode, void opaque)
		{
		const erofs_nid_t nid = (erofs_nid_t )opaque;

		return EROFS_V(inode)->nid == nid;
		}

		static int erofs_iget_set_actor(struct inode inode, void opaque)
		{
		const erofs_nid_t nid = (erofs_nid_t )opaque;

		inode->i_ino = erofs_inode_hash(nid);
		return 0;
		}
		#endif

		static inline struct inode erofs_iget_locked(struct super_block sb,
		erofs_nid_t nid)
		{
		const unsigned long hashval = erofs_inode_hash(nid);

		#if BITS_PER_LONG >= 64
		/* it is safe to use iget_locked for >= 64-bit platform */
		return iget_locked(sb, hashval);
		#else
		return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
		erofs_iget_set_actor, &nid);
		#endif
		}

		struct inode erofs_iget(struct super_block sb,
		erofs_nid_t nid, bool isdir)
		{
		struct inode *inode = iget_locked(sb, nid);
		struct inode *inode = erofs_iget_locked(sb, nid);

		if (unlikely(inode == NULL))
		return ERR_PTR(-ENOMEM);

+9 −0

Original line number	Diff line number	Diff line
		@@ -517,6 +517,15 @@ erofs_get_inline_page(struct inode *inode,
		}

		/* inode.c */
		static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
		{
		#if BITS_PER_LONG == 32
		return (nid >> 32) ^ (nid & 0xffffffff);
		#else
		return nid;
		#endif
		}

		extern struct inode erofs_iget(struct super_block sb,
		erofs_nid_t nid, bool dir);