Merge remote-tracking branch 'origin/upstream-f2fs-stable-linux-4.4.y' into android-4.4

6944da0a68ca treewide: Use array_size in f2fs_kvzalloc()
f15443db99c3 treewide: Use array_size() in f2fs_kzalloc()
3ea03ea4bd09 treewide: Use array_size() in f2fs_kmalloc()
c41203299a52 overflow.h: Add allocation size calculation helpers
d400752f547f f2fs: fix to clear FI_VOLATILE_FILE correctly
853e7339b634 f2fs: let sync node IO interrupt async one
6a4540cf1984 f2fs: don't change wbc->sync_mode
588ecdfd7d02 f2fs: fix to update mtime correctly
1ae5aadab191 fs: f2fs: insert space around that ':' and ', '
39ee53e22320 fs: f2fs: add missing blank lines after declarations
d5b4710fcf38 fs: f2fs: changed variable type of offset "unsigned" to "loff_t"
c35da89531b3 f2fs: clean up symbol namespace
fcf37e16f3cb f2fs: make set_de_type() static
5d1633aa1071 f2fs: make __f2fs_write_data_pages() static
cc8093af7c42 f2fs: fix to avoid accessing cross the boundary
b7f559467095 f2fs: fix to let caller retry allocating block address
e48fcd857657 disable loading f2fs module on PAGE_SIZE > 4KB
02afc275a5bd f2fs: fix error path of move_data_page
0291bd36d076 f2fs: don't drop dentry pages after fs shutdown
a1259450b6db f2fs: fix to avoid race during access gc_thread pointer
d2e0f2f786a6 f2fs: clean up with clear_radix_tree_dirty_tag
c74034518fdc f2fs: fix to don't trigger writeback during recovery
e72a2cca82d8 f2fs: clear discard_wake earlier
b25a1872e9a5 f2fs: let discard thread wait a little longer if dev is busy
b125dfb20d18 f2fs: avoid stucking GC due to atomic write
405909e7f532 f2fs: introduce sbi->gc_mode to determine the policy
1f62e4702a34 f2fs: keep migration IO order in LFS mode
c4408c238722 f2fs: fix to wait page writeback during revoking atomic write
9db5be4af890 f2fs: Fix deadlock in shutdown ioctl
ed74404955cd f2fs: detect synchronous writeback more earlier
91e7d9d2ddbf mm: remove nr_pages argument from pagevec_lookup_{,range}_tag()
feb94dc82928 ceph: use pagevec_lookup_range_nr_tag()
f3aa4a25b8b0 mm: add variant of pagevec_lookup_range_tag() taking number of pages
8914877e374a mm: use pagevec_lookup_range_tag() in write_cache_pages()
26778b87a006 mm: use pagevec_lookup_range_tag() in __filemap_fdatawait_range()
94f1b99298bd nilfs2: use pagevec_lookup_range_tag()
160355d69f46 gfs2: use pagevec_lookup_range_tag()
564108e83a74 f2fs: use find_get_pages_tag() for looking up single page
6cf6fb8645ff f2fs: simplify page iteration loops
a05d8a6a2bde f2fs: use pagevec_lookup_range_tag()
18a4848ffded ext4: use pagevec_lookup_range_tag()
1c7be24f65cd ceph: use pagevec_lookup_range_tag()
e25fadabb5c7 btrfs: use pagevec_lookup_range_tag()
bf9510b162c4 mm: implement find_get_pages_range_tag()
461247b21fde f2fs: clean up with is_valid_blkaddr()
a5d0ccbc189a f2fs: fix to initialize min_mtime with ULLONG_MAX
9bb4d22cf5de f2fs: fix to let checkpoint guarantee atomic page persistence
cdcf2b3e2559 f2fs: fix to initialize i_current_depth according to inode type
331ae0c25b44 Revert "f2fs: add ovp valid_blocks check for bg gc victim to fg_gc"
2494cc7c0bcd f2fs: don't drop any page on f2fs_cp_error() case
0037c639e63d f2fs: fix spelling mistake: "extenstion" -> "extension"
2bba5b8eb867 f2fs: enhance sanity_check_raw_super() to avoid potential overflows
9bb86b63dc0f f2fs: treat volatile file's data as hot one
2cf64590361e f2fs: introduce release_discard_addr() for cleanup
03279ce90b46 f2fs: fix potential overflow
f46eddc4da48 f2fs: rename dio_rwsem to i_gc_rwsem
bb015824532c f2fs: move mnt_want_write_file after range check
8bb9a8da75d1 f2fs: fix missing clear FI_NO_PREALLOC in some error case
cb38cc4e1d02 f2fs: enforce fsync_mode=strict for renamed directory
26bf4e8a96aa f2fs: sanity check for total valid node blocks
78f8b0f46fa2 f2fs: sanity check on sit entry
ab758ada220f f2fs: avoid bug_on on corrupted inode
1a5d1966c0ca f2fs: give message and set need_fsck given broken node id
b025f6dfc018 f2fs: clean up commit_inmem_pages()
7aff5c69da4c f2fs: do not check F2FS_INLINE_DOTS in recover
23d00b02878e f2fs: remove duplicated dquot_initialize and fix error handling
937f4ef79e25 f2fs: stop issue discard if something wrong with f2fs
a6d74bb282ad f2fs: fix return value in f2fs_ioc_commit_atomic_write
258489ec5220 f2fs: allocate hot_data for atomic write more strictly
aa857e0f3b09 f2fs: check if inmem_pages list is empty correctly
9d77ded0a71d f2fs: fix race in between GC and atomic open
0d17eb90b56a f2fs: change le32 to le16 of f2fs_inode->i_extra_size
ea2813111f1f f2fs: check cur_valid_map_mir & raw_sit block count when flush sit entries
9190cadf38db f2fs: correct return value of f2fs_trim_fs
17f85d070886 f2fs: fix to show missing bits in FS_IOC_GETFLAGS
3e90db63fcfc f2fs: remove unneeded F2FS_PROJINHERIT_FL
298032d4d4a6 f2fs: don't use GFP_ZERO for page caches
fdf61219dc25 f2fs: issue all big range discards in umount process
cd79eb2b5e45 f2fs: remove redundant block plug
ec034d0f14ca f2fs: remove unmatched zero_user_segment when convert inline dentry
71aaced0e1ee f2fs: introduce private inode status mapping
e7724207f71e fscrypt: log the crypto algorithm implementations
4cbda579cd3d crypto: api - Add crypto_type_has_alg helper
b24dcaae8753 crypto: skcipher - Add low-level skcipher interface
a9146e423547 crypto: skcipher - Add helper to retrieve driver name
a0ca4bdf4744 crypto: skcipher - Add default key size helper
eb13e0b69296 fscrypt: add Speck128/256 support
27a0e77380a3 fscrypt: only derive the needed portion of the key
f68a71fa8f77 fscrypt: separate key lookup from key derivation
52359cf4fd6d fscrypt: use a common logging function
ff8e7c745e2b fscrypt: remove internal key size constants
7149dd4d39b5 fscrypt: remove unnecessary check for non-logon key type
56446c91422e fscrypt: make fscrypt_operations.max_namelen an integer
f572a22ef9a5 fscrypt: drop empty name check from fname_decrypt()
0077eff1d2e3 fscrypt: drop max_namelen check from fname_decrypt()
3f7af9d27fd6 fscrypt: don't special-case EOPNOTSUPP from fscrypt_get_encryption_info()
52c51f7b7bde fscrypt: don't clear flags on crypto transform
89b7fb82982f fscrypt: remove stale comment from fscrypt_d_revalidate()
d56de4e926ad fscrypt: remove error messages for skcipher_request_alloc() failure
f68d3b84aef1 fscrypt: remove unnecessary NULL check when allocating skcipher
fb10231825e9 fscrypt: clean up after fscrypt_prepare_lookup() conversions
39b144490606 fscrypt: use unbound workqueue for decryption

Change-Id: Ied79ecd97385c05ef26e6b7b24d250eee9ec4e47
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>

8 files changed, 532 insertions, 33 deletions

diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h
index 2cf7a61ece59..ce6619c339fe 100644
--- a/include/crypto/internal/skcipher.h
+++ b/include/crypto/internal/skcipher.h
@@ -19,12 +19,46 @@
 
 struct rtattr;
 
+struct skcipher_instance {
+	void (*free)(struct skcipher_instance *inst);
+	union {
+		struct {
+			char head[offsetof(struct skcipher_alg, base)];
+			struct crypto_instance base;
+		} s;
+		struct skcipher_alg alg;
+	};
+};
+
 struct crypto_skcipher_spawn {
 	struct crypto_spawn base;
 };
 
 extern const struct crypto_type crypto_givcipher_type;
 
+static inline struct crypto_instance *skcipher_crypto_instance(
+	struct skcipher_instance *inst)
+{
+	return &inst->s.base;
+}
+
+static inline struct skcipher_instance *skcipher_alg_instance(
+	struct crypto_skcipher *skcipher)
+{
+	return container_of(crypto_skcipher_alg(skcipher),
+			    struct skcipher_instance, alg);
+}
+
+static inline void *skcipher_instance_ctx(struct skcipher_instance *inst)
+{
+	return crypto_instance_ctx(skcipher_crypto_instance(inst));
+}
+
+static inline void skcipher_request_complete(struct skcipher_request *req, int err)
+{
+	req->base.complete(&req->base, err);
+}
+
 static inline void crypto_set_skcipher_spawn(
 	struct crypto_skcipher_spawn *spawn, struct crypto_instance *inst)
 {
@@ -33,6 +67,8 @@ static inline void crypto_set_skcipher_spawn(
 
 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 			 u32 type, u32 mask);
+int crypto_grab_skcipher2(struct crypto_skcipher_spawn *spawn,
+			  const char *name, u32 type, u32 mask);
 
 struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask);
 
@@ -47,6 +83,12 @@ static inline struct crypto_alg *crypto_skcipher_spawn_alg(
 	return spawn->base.alg;
 }
 
+static inline struct skcipher_alg *crypto_spawn_skcipher_alg(
+	struct crypto_skcipher_spawn *spawn)
+{
+	return container_of(spawn->base.alg, struct skcipher_alg, base);
+}
+
 static inline struct crypto_ablkcipher *crypto_spawn_skcipher(
 	struct crypto_skcipher_spawn *spawn)
 {
@@ -55,6 +97,25 @@ static inline struct crypto_ablkcipher *crypto_spawn_skcipher(
 				 crypto_skcipher_mask(0)));
 }
 
+static inline struct crypto_skcipher *crypto_spawn_skcipher2(
+	struct crypto_skcipher_spawn *spawn)
+{
+	return crypto_spawn_tfm2(&spawn->base);
+}
+
+static inline void crypto_skcipher_set_reqsize(
+	struct crypto_skcipher *skcipher, unsigned int reqsize)
+{
+	skcipher->reqsize = reqsize;
+}
+
+int crypto_register_skcipher(struct skcipher_alg *alg);
+void crypto_unregister_skcipher(struct skcipher_alg *alg);
+int crypto_register_skciphers(struct skcipher_alg *algs, int count);
+void crypto_unregister_skciphers(struct skcipher_alg *algs, int count);
+int skcipher_register_instance(struct crypto_template *tmpl,
+			       struct skcipher_instance *inst);
+
 int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req);
 int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req);
 const char *crypto_default_geniv(const struct crypto_alg *alg);
@@ -122,5 +183,31 @@ static inline u32 skcipher_request_flags(struct skcipher_request *req)
 	return req->base.flags;
 }
 
+static inline unsigned int crypto_skcipher_alg_min_keysize(
+	struct skcipher_alg *alg)
+{
+	if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER)
+		return alg->base.cra_blkcipher.min_keysize;
+
+	if (alg->base.cra_ablkcipher.encrypt)
+		return alg->base.cra_ablkcipher.min_keysize;
+
+	return alg->min_keysize;
+}
+
+static inline unsigned int crypto_skcipher_alg_max_keysize(
+	struct skcipher_alg *alg)
+{
+	if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER)
+		return alg->base.cra_blkcipher.max_keysize;
+
+	if (alg->base.cra_ablkcipher.encrypt)
+		return alg->base.cra_ablkcipher.max_keysize;
+
+	return alg->max_keysize;
+}
+
 #endif	/* _CRYPTO_INTERNAL_SKCIPHER_H */
 
diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h
index fd8742a40ff3..5c90d3edf975 100644
--- a/include/crypto/skcipher.h
+++ b/include/crypto/skcipher.h
@@ -60,12 +60,80 @@ struct crypto_skcipher {
 
 	unsigned int ivsize;
 	unsigned int reqsize;
-
-	bool has_setkey;
+	unsigned int keysize;
 
 	struct crypto_tfm base;
 };
 
+/**
+ * struct skcipher_alg - symmetric key cipher definition
+ * @min_keysize: Minimum key size supported by the transformation. This is the
+ *		 smallest key length supported by this transformation algorithm.
+ *		 This must be set to one of the pre-defined values as this is
+ *		 not hardware specific. Possible values for this field can be
+ *		 found via git grep "_MIN_KEY_SIZE" include/crypto/
+ * @max_keysize: Maximum key size supported by the transformation. This is the
+ *		 largest key length supported by this transformation algorithm.
+ *		 This must be set to one of the pre-defined values as this is
+ *		 not hardware specific. Possible values for this field can be
+ *		 found via git grep "_MAX_KEY_SIZE" include/crypto/
+ * @setkey: Set key for the transformation. This function is used to either
+ *	    program a supplied key into the hardware or store the key in the
+ *	    transformation context for programming it later. Note that this
+ *	    function does modify the transformation context. This function can
+ *	    be called multiple times during the existence of the transformation
+ *	    object, so one must make sure the key is properly reprogrammed into
+ *	    the hardware. This function is also responsible for checking the key
+ *	    length for validity. In case a software fallback was put in place in
+ *	    the @cra_init call, this function might need to use the fallback if
+ *	    the algorithm doesn't support all of the key sizes.
+ * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt
+ *	     the supplied scatterlist containing the blocks of data. The crypto
+ *	     API consumer is responsible for aligning the entries of the
+ *	     scatterlist properly and making sure the chunks are correctly
+ *	     sized. In case a software fallback was put in place in the
+ *	     @cra_init call, this function might need to use the fallback if
+ *	     the algorithm doesn't support all of the key sizes. In case the
+ *	     key was stored in transformation context, the key might need to be
+ *	     re-programmed into the hardware in this function. This function
+ *	     shall not modify the transformation context, as this function may
+ *	     be called in parallel with the same transformation object.
+ * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt
+ *	     and the conditions are exactly the same.
+ * @init: Initialize the cryptographic transformation object. This function
+ *	  is used to initialize the cryptographic transformation object.
+ *	  This function is called only once at the instantiation time, right
+ *	  after the transformation context was allocated. In case the
+ *	  cryptographic hardware has some special requirements which need to
+ *	  be handled by software, this function shall check for the precise
+ *	  requirement of the transformation and put any software fallbacks
+ *	  in place.
+ * @exit: Deinitialize the cryptographic transformation object. This is a
+ *	  counterpart to @init, used to remove various changes set in
+ *	  @init.
+ * @ivsize: IV size applicable for transformation. The consumer must provide an
+ *	    IV of exactly that size to perform the encrypt or decrypt operation.
+ * @chunksize: Equal to the block size except for stream ciphers such as
+ *	       CTR where it is set to the underlying block size.
+ *
+ * All fields except @ivsize are mandatory and must be filled.
+ */
+struct skcipher_alg {
+	int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
+	              unsigned int keylen);
+	int (*encrypt)(struct skcipher_request *req);
+	int (*decrypt)(struct skcipher_request *req);
+	int (*init)(struct crypto_skcipher *tfm);
+	void (*exit)(struct crypto_skcipher *tfm);
+
+	unsigned int min_keysize;
+	unsigned int max_keysize;
+	unsigned int ivsize;
+	unsigned int chunksize;
+
+	struct crypto_alg base;
+};
+
 #define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
 	char __##name##_desc[sizeof(struct skcipher_request) + \
 		crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
@@ -233,6 +301,43 @@ static inline int crypto_has_skcipher(const char *alg_name, u32 type,
 }
 
 /**
+ * crypto_has_skcipher2() - Search for the availability of an skcipher.
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	      skcipher
+ * @type: specifies the type of the skcipher
+ * @mask: specifies the mask for the skcipher
+ *
+ * Return: true when the skcipher is known to the kernel crypto API; false
+ *	   otherwise
+ */
+int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask);
+
+static inline const char *crypto_skcipher_driver_name(
+	struct crypto_skcipher *tfm)
+{
+	return crypto_tfm_alg_name(crypto_skcipher_tfm(tfm));
+}
+
+static inline struct skcipher_alg *crypto_skcipher_alg(
+	struct crypto_skcipher *tfm)
+{
+	return container_of(crypto_skcipher_tfm(tfm)->__crt_alg,
+			    struct skcipher_alg, base);
+}
+
+static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg)
+{
+	if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER)
+		return alg->base.cra_blkcipher.ivsize;
+
+	if (alg->base.cra_ablkcipher.encrypt)
+		return alg->base.cra_ablkcipher.ivsize;
+
+	return alg->ivsize;
+}
+
+/**
  * crypto_skcipher_ivsize() - obtain IV size
  * @tfm: cipher handle
  *
@@ -246,6 +351,36 @@ static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
 	return tfm->ivsize;
 }
 
+static inline unsigned int crypto_skcipher_alg_chunksize(
+	struct skcipher_alg *alg)
+{
+	if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER)
+		return alg->base.cra_blocksize;
+
+	if (alg->base.cra_ablkcipher.encrypt)
+		return alg->base.cra_blocksize;
+
+	return alg->chunksize;
+}
+
+/**
+ * crypto_skcipher_chunksize() - obtain chunk size
+ * @tfm: cipher handle
+ *
+ * The block size is set to one for ciphers such as CTR.  However,
+ * you still need to provide incremental updates in multiples of
+ * the underlying block size as the IV does not have sub-block
+ * granularity.  This is known in this API as the chunk size.
+ *
+ * Return: chunk size in bytes
+ */
+static inline unsigned int crypto_skcipher_chunksize(
+	struct crypto_skcipher *tfm)
+{
+	return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
+}
+
 /**
  * crypto_skcipher_blocksize() - obtain block size of cipher
  * @tfm: cipher handle
@@ -309,7 +444,13 @@ static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
 
 static inline bool crypto_skcipher_has_setkey(struct crypto_skcipher *tfm)
 {
-	return tfm->has_setkey;
+	return tfm->keysize;
+}
+
+static inline unsigned int crypto_skcipher_default_keysize(
+	struct crypto_skcipher *tfm)
+{
+	return tfm->keysize;
 }
 
 /**
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index b7c1e1a7ebac..d7c8b37b2e95 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -48,6 +48,7 @@
 #define CRYPTO_ALG_TYPE_AEAD		0x00000003
 #define CRYPTO_ALG_TYPE_BLKCIPHER	0x00000004
 #define CRYPTO_ALG_TYPE_ABLKCIPHER	0x00000005
+#define CRYPTO_ALG_TYPE_SKCIPHER	0x00000005
 #define CRYPTO_ALG_TYPE_GIVCIPHER	0x00000006
 #define CRYPTO_ALG_TYPE_DIGEST		0x00000008
 #define CRYPTO_ALG_TYPE_HASH		0x00000008
diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h
index 44bd4fbd3ec5..e2729c6d9829 100644
--- a/include/linux/fscrypt_notsupp.h
+++ b/include/linux/fscrypt_notsupp.h
@@ -67,16 +67,6 @@ static inline void fscrypt_restore_control_page(struct page *page)
 	return;
 }
 
-static inline void fscrypt_set_d_op(struct dentry *dentry)
-{
-	return;
-}
-
-static inline void fscrypt_set_encrypted_dentry(struct dentry *dentry)
-{
-	return;
-}
-
 /* policy.c */
 static inline int fscrypt_ioctl_set_policy(struct file *filp,
 					   const void __user *arg)
diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h
index 9d1857302b73..46b62d82b6d6 100644
--- a/include/linux/fscrypt_supp.h
+++ b/include/linux/fscrypt_supp.h
@@ -28,7 +28,7 @@ struct fscrypt_operations {
 	int (*set_context)(struct inode *, const void *, size_t, void *);
 	bool (*dummy_context)(struct inode *);
 	bool (*empty_dir)(struct inode *);
-	unsigned (*max_namelen)(struct inode *);
+	unsigned int max_namelen;
 };
 
 struct fscrypt_ctx {
@@ -74,20 +74,6 @@ static inline struct page *fscrypt_control_page(struct page *page)
 
 extern void fscrypt_restore_control_page(struct page *);
 
-extern const struct dentry_operations fscrypt_d_ops;
-
-static inline void fscrypt_set_d_op(struct dentry *dentry)
-{
-	d_set_d_op(dentry, &fscrypt_d_ops);
-}
-
-static inline void fscrypt_set_encrypted_dentry(struct dentry *dentry)
-{
-	spin_lock(&dentry->d_lock);
-	dentry->d_flags |= DCACHE_ENCRYPTED_WITH_KEY;
-	spin_unlock(&dentry->d_lock);
-}
-
 /* policy.c */
 extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
 extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
diff --git a/include/linux/overflow.h b/include/linux/overflow.h
new file mode 100644
index 000000000000..8712ff70995f
--- /dev/null
+++ b/include/linux/overflow.h
@@ -0,0 +1,278 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+#ifndef __LINUX_OVERFLOW_H
+#define __LINUX_OVERFLOW_H
+
+#include <linux/compiler.h>
+
+/*
+ * In the fallback code below, we need to compute the minimum and
+ * maximum values representable in a given type. These macros may also
+ * be useful elsewhere, so we provide them outside the
+ * COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW block.
+ *
+ * It would seem more obvious to do something like
+ *
+ * #define type_min(T) (T)(is_signed_type(T) ? (T)1 << (8*sizeof(T)-1) : 0)
+ * #define type_max(T) (T)(is_signed_type(T) ? ((T)1 << (8*sizeof(T)-1)) - 1 : ~(T)0)
+ *
+ * Unfortunately, the middle expressions, strictly speaking, have
+ * undefined behaviour, and at least some versions of gcc warn about
+ * the type_max expression (but not if -fsanitize=undefined is in
+ * effect; in that case, the warning is deferred to runtime...).
+ *
+ * The slightly excessive casting in type_min is to make sure the
+ * macros also produce sensible values for the exotic type _Bool. [The
+ * overflow checkers only almost work for _Bool, but that's
+ * a-feature-not-a-bug, since people shouldn't be doing arithmetic on
+ * _Bools. Besides, the gcc builtins don't allow _Bool* as third
+ * argument.]
+ *
+ * Idea stolen from
+ * https://mail-index.netbsd.org/tech-misc/2007/02/05/0000.html -
+ * credit to Christian Biere.
+ */
+#define is_signed_type(type)       (((type)(-1)) < (type)1)
+#define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type)))
+#define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T)))
+#define type_min(T) ((T)((T)-type_max(T)-(T)1))
+
+
+#ifdef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW
+/*
+ * For simplicity and code hygiene, the fallback code below insists on
+ * a, b and *d having the same type (similar to the min() and max()
+ * macros), whereas gcc's type-generic overflow checkers accept
+ * different types. Hence we don't just make check_add_overflow an
+ * alias for __builtin_add_overflow, but add type checks similar to
+ * below.
+ */
+#define check_add_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	__builtin_add_overflow(__a, __b, __d);	\
+})
+
+#define check_sub_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	__builtin_sub_overflow(__a, __b, __d);	\
+})
+
+#define check_mul_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	__builtin_mul_overflow(__a, __b, __d);	\
+})
+
+#else
+
+
+/* Checking for unsigned overflow is relatively easy without causing UB. */
+#define __unsigned_add_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = __a + __b;			\
+	*__d < __a;				\
+})
+#define __unsigned_sub_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = __a - __b;			\
+	__a < __b;				\
+})
+/*
+ * If one of a or b is a compile-time constant, this avoids a division.
+ */
+#define __unsigned_mul_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);				\
+	typeof(b) __b = (b);				\
+	typeof(d) __d = (d);				\
+	(void) (&__a == &__b);				\
+	(void) (&__a == __d);				\
+	*__d = __a * __b;				\
+	__builtin_constant_p(__b) ?			\
+	  __b > 0 && __a > type_max(typeof(__a)) / __b : \
+	  __a > 0 && __b > type_max(typeof(__b)) / __a;	 \
+})
+
+/*
+ * For signed types, detecting overflow is much harder, especially if
+ * we want to avoid UB. But the interface of these macros is such that
+ * we must provide a result in *d, and in fact we must produce the
+ * result promised by gcc's builtins, which is simply the possibly
+ * wrapped-around value. Fortunately, we can just formally do the
+ * operations in the widest relevant unsigned type (u64) and then
+ * truncate the result - gcc is smart enough to generate the same code
+ * with and without the (u64) casts.
+ */
+
+/*
+ * Adding two signed integers can overflow only if they have the same
+ * sign, and overflow has happened iff the result has the opposite
+ * sign.
+ */
+#define __signed_add_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = (u64)__a + (u64)__b;		\
+	(((~(__a ^ __b)) & (*__d ^ __a))	\
+		& type_min(typeof(__a))) != 0;	\
+})
+
+/*
+ * Subtraction is similar, except that overflow can now happen only
+ * when the signs are opposite. In this case, overflow has happened if
+ * the result has the opposite sign of a.
+ */
+#define __signed_sub_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = (u64)__a - (u64)__b;		\
+	((((__a ^ __b)) & (*__d ^ __a))		\
+		& type_min(typeof(__a))) != 0;	\
+})
+
+/*
+ * Signed multiplication is rather hard. gcc always follows C99, so
+ * division is truncated towards 0. This means that we can write the
+ * overflow check like this:
+ *
+ * (a > 0 && (b > MAX/a || b < MIN/a)) ||
+ * (a < -1 && (b > MIN/a || b < MAX/a) ||
+ * (a == -1 && b == MIN)
+ *
+ * The redundant casts of -1 are to silence an annoying -Wtype-limits
+ * (included in -Wextra) warning: When the type is u8 or u16, the
+ * __b_c_e in check_mul_overflow obviously selects
+ * __unsigned_mul_overflow, but unfortunately gcc still parses this
+ * code and warns about the limited range of __b.
+ */
+
+#define __signed_mul_overflow(a, b, d) ({				\
+	typeof(a) __a = (a);						\
+	typeof(b) __b = (b);						\
+	typeof(d) __d = (d);						\
+	typeof(a) __tmax = type_max(typeof(a));				\
+	typeof(a) __tmin = type_min(typeof(a));				\
+	(void) (&__a == &__b);						\
+	(void) (&__a == __d);						\
+	*__d = (u64)__a * (u64)__b;					\
+	(__b > 0   && (__a > __tmax/__b || __a < __tmin/__b)) ||	\
+	(__b < (typeof(__b))-1  && (__a > __tmin/__b || __a < __tmax/__b)) || \
+	(__b == (typeof(__b))-1 && __a == __tmin);			\
+})
+
+
+#define check_add_overflow(a, b, d)					\
+	__builtin_choose_expr(is_signed_type(typeof(a)),		\
+			__signed_add_overflow(a, b, d),			\
+			__unsigned_add_overflow(a, b, d))
+
+#define check_sub_overflow(a, b, d)					\
+	__builtin_choose_expr(is_signed_type(typeof(a)),		\
+			__signed_sub_overflow(a, b, d),			\
+			__unsigned_sub_overflow(a, b, d))
+
+#define check_mul_overflow(a, b, d)					\
+	__builtin_choose_expr(is_signed_type(typeof(a)),		\
+			__signed_mul_overflow(a, b, d),			\
+			__unsigned_mul_overflow(a, b, d))
+
+
+#endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */
+
+/**
+ * array_size() - Calculate size of 2-dimensional array.
+ *
+ * @a: dimension one
+ * @b: dimension two
+ *
+ * Calculates size of 2-dimensional array: @a * @b.
+ *
+ * Returns: number of bytes needed to represent the array or SIZE_MAX on
+ * overflow.
+ */
+static inline __must_check size_t array_size(size_t a, size_t b)
+{
+	size_t bytes;
+
+	if (check_mul_overflow(a, b, &bytes))
+		return SIZE_MAX;
+
+	return bytes;
+}
+
+/**
+ * array3_size() - Calculate size of 3-dimensional array.
+ *
+ * @a: dimension one
+ * @b: dimension two
+ * @c: dimension three
+ *
+ * Calculates size of 3-dimensional array: @a * @b * @c.
+ *
+ * Returns: number of bytes needed to represent the array or SIZE_MAX on
+ * overflow.
+ */
+static inline __must_check size_t array3_size(size_t a, size_t b, size_t c)
+{
+	size_t bytes;
+
+	if (check_mul_overflow(a, b, &bytes))
+		return SIZE_MAX;
+	if (check_mul_overflow(bytes, c, &bytes))
+		return SIZE_MAX;
+
+	return bytes;
+}
+
+static inline __must_check size_t __ab_c_size(size_t n, size_t size, size_t c)
+{
+	size_t bytes;
+
+	if (check_mul_overflow(n, size, &bytes))
+		return SIZE_MAX;
+	if (check_add_overflow(bytes, c, &bytes))
+		return SIZE_MAX;
+
+	return bytes;
+}
+
+/**
+ * struct_size() - Calculate size of structure with trailing array.
+ * @p: Pointer to the structure.
+ * @member: Name of the array member.
+ * @n: Number of elements in the array.
+ *
+ * Calculates size of memory needed for structure @p followed by an
+ * array of @n @member elements.
+ *
+ * Return: number of bytes needed or SIZE_MAX on overflow.
+ */
+#define struct_size(p, member, n)					\
+	__ab_c_size(n,							\
+		    sizeof(*(p)->member) + __must_be_array((p)->member),\
+		    sizeof(*(p)))
+
+#endif /* __LINUX_OVERFLOW_H */
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 771774e13f10..443a063e6af8 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -359,8 +359,16 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
 			unsigned int nr_pages, struct page **pages);
 unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
 			       unsigned int nr_pages, struct page **pages);
-unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
-			int tag, unsigned int nr_pages, struct page **pages);
+unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
+			pgoff_t end, int tag, unsigned int nr_pages,
+			struct page **pages);
+static inline unsigned find_get_pages_tag(struct address_space *mapping,
+			pgoff_t *index, int tag, unsigned int nr_pages,
+			struct page **pages)
+{
+	return find_get_pages_range_tag(mapping, index, (pgoff_t)-1, tag,
+					nr_pages, pages);
+}
 
 struct page *grab_cache_page_write_begin(struct address_space *mapping,
 			pgoff_t index, unsigned flags);
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
index b45d391b4540..cead4419f933 100644
--- a/include/linux/pagevec.h
+++ b/include/linux/pagevec.h
@@ -29,9 +29,17 @@ unsigned pagevec_lookup_entries(struct pagevec *pvec,
 void pagevec_remove_exceptionals(struct pagevec *pvec);
 unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
 		pgoff_t start, unsigned nr_pages);
-unsigned pagevec_lookup_tag(struct pagevec *pvec,
-		struct address_space *mapping, pgoff_t *index, int tag,
-		unsigned nr_pages);
+unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
+		struct address_space *mapping, pgoff_t *index, pgoff_t end,
+		int tag);
+unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec,
+		struct address_space *mapping, pgoff_t *index, pgoff_t end,
+		int tag, unsigned max_pages);
+static inline unsigned pagevec_lookup_tag(struct pagevec *pvec,
+		struct address_space *mapping, pgoff_t *index, int tag)
+{
+	return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag);
+}
 
 static inline void pagevec_init(struct pagevec *pvec, int cold)
 {