Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
"This merge request includes the dax-4.0-iomap-pmd branch which is
needed for both ext4 and xfs dax changes to use iomap for DAX. It also
includes the fscrypt branch which is needed for ubifs encryption work
as well as ext4 encryption and fscrypt cleanups.

Lots of cleanups and bug fixes, especially making sure ext4 is robust
against maliciously corrupted file systems --- especially maliciously
corrupted xattr blocks and a maliciously corrupted superblock. Also
fix ext4 support for 64k block sizes so it works well on ppcle. Fixed
mbcache so we don't miss some common xattr blocks that can be merged"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (86 commits)
dax: Fix sleep in atomic contex in grab_mapping_entry()
fscrypt: Rename FS_WRITE_PATH_FL to FS_CTX_HAS_BOUNCE_BUFFER_FL
fscrypt: Delay bounce page pool allocation until needed
fscrypt: Cleanup page locking requirements for fscrypt_{decrypt,encrypt}_page()
fscrypt: Cleanup fscrypt_{decrypt,encrypt}_page()
fscrypt: Never allocate fscrypt_ctx on in-place encryption
fscrypt: Use correct index in decrypt path.
fscrypt: move the policy flags and encryption mode definitions to uapi header
fscrypt: move non-public structures and constants to fscrypt_private.h
fscrypt: unexport fscrypt_initialize()
fscrypt: rename get_crypt_info() to fscrypt_get_crypt_info()
fscrypto: move ioctl processing more fully into common code
fscrypto: remove unneeded Kconfig dependencies
MAINTAINERS: fscrypto: recommend linux-fsdevel for fscrypto patches
ext4: do not perform data journaling when data is encrypted
ext4: return -ENOMEM instead of success
ext4: reject inodes with negative size
ext4: remove another test in ext4_alloc_file_blocks()
Documentation: fix description of ext4's block_validity mount option
ext4: fix checks for data=ordered and journal_async_commit options
...

Documentation/filesystems/dax.txt

···
 Filesystem support consists of
 - adding support to mark inodes as being DAX by setting the S_DAX flag in
   i_flags
-- implementing the direct_IO address space operation, and calling
-  dax_do_io() instead of blockdev_direct_IO() if S_DAX is set
+- implementing ->read_iter and ->write_iter operations which use dax_iomap_rw()
+  when inode has S_DAX flag set
 - implementing an mmap file operation for DAX files which sets the
   VM_MIXEDMAP and VM_HUGEPAGE flags on the VMA, and setting the vm_ops to
-  include handlers for fault, pmd_fault and page_mkwrite (which should
-  probably call dax_fault(), dax_pmd_fault() and dax_mkwrite(), passing the
-  appropriate get_block() callback)
-- calling dax_truncate_page() instead of block_truncate_page() for DAX files
-- calling dax_zero_page_range() instead of zero_user() for DAX files
+  include handlers for fault, pmd_fault, page_mkwrite, pfn_mkwrite. These
+  handlers should probably call dax_iomap_fault() (for fault and page_mkwrite
+  handlers), dax_iomap_pmd_fault(), dax_pfn_mkwrite() passing the appropriate
+  iomap operations.
+- calling iomap_zero_range() passing appropriate iomap operations instead of
+  block_truncate_page() for DAX files
 - ensuring that there is sufficient locking between reads, writes,
   truncates and page faults
 
-The get_block() callback passed to the DAX functions may return
-uninitialised extents.  If it does, it must ensure that simultaneous
-calls to get_block() (for example by a page-fault racing with a read()
-or a write()) work correctly.
+The iomap handlers for allocating blocks must make sure that allocated blocks
+are zeroed out and converted to written extents before being returned to avoid
+exposure of uninitialized data through mmap.
 
 These filesystems may be used for inspiration:
 - ext2: see Documentation/filesystems/ext2.txt

Documentation/filesystems/ext4.txt

···
 			interoperability  with  older kernels which only
 			store and expect 16-bit values.
 
-block_validity		This options allows to enables/disables the in-kernel
+block_validity(*)	These options enable or disable the in-kernel
 noblock_validity	facility for tracking filesystem metadata blocks
-			within internal data structures. This allows multi-
-			block allocator and other routines to quickly locate
-			extents which might overlap with filesystem metadata
-			blocks. This option is intended for debugging
-			purposes and since it negatively affects the
-			performance, it is off by default.
+			within internal data structures.  This allows multi-
+			block allocator and other routines to notice
+			bugs or corrupted allocation bitmaps which cause
+			blocks to be allocated which overlap with
+			filesystem metadata blocks.
 
 dioread_lock		Controls whether or not ext4 should use the DIO read
 dioread_nolock		locking. If the dioread_nolock option is specified

MAINTAINERS

···
 FS-CRYPTO: FILE SYSTEM LEVEL ENCRYPTION SUPPORT
 M:	Theodore Y. Ts'o <[e-mail]>
 M:	Jaegeuk Kim <[e-mail]>
+L:	[e-mail]
 S:	Supported
 F:	fs/crypto/
 F:	include/linux/fscrypto.h

fs/Kconfig

···
 	depends on FS_DAX
 	depends on ZONE_DEVICE
 	depends on TRANSPARENT_HUGEPAGE
-	depends on BROKEN
 
 endif # BLOCK
 

fs/crypto/Kconfig

···
 	select CRYPTO_XTS
 	select CRYPTO_CTS
 	select CRYPTO_CTR
-	select CRYPTO_SHA256
 	select KEYS
-	select ENCRYPTED_KEYS
 	help
 	  Enable encryption of files and directories.  This
 	  feature is similar to ecryptfs, but it is more memory

fs/crypto/crypto.c

···
 #include <linux/bio.h>
 #include <linux/dcache.h>
 #include <linux/namei.h>
-#include <linux/fscrypto.h>
+#include "fscrypt_private.h"
 
 static unsigned int num_prealloc_crypto_pages = 32;
 static unsigned int num_prealloc_crypto_ctxs = 128;
···
 {
 	unsigned long flags;
 
-	if (ctx->flags & FS_WRITE_PATH_FL && ctx->w.bounce_page) {
+	if (ctx->flags & FS_CTX_HAS_BOUNCE_BUFFER_FL && ctx->w.bounce_page) {
 		mempool_free(ctx->w.bounce_page, fscrypt_bounce_page_pool);
 		ctx->w.bounce_page = NULL;
 	}
···
  * Return: An allocated and initialized encryption context on success; error
  * value or NULL otherwise.
  */
-struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode, gfp_t gfp_flags)
+struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode, gfp_t gfp_flags)
 {
 	struct fscrypt_ctx *ctx = NULL;
 	struct fscrypt_info *ci = inode->i_crypt_info;
···
 	} else {
 		ctx->flags &= ~FS_CTX_REQUIRES_FREE_ENCRYPT_FL;
 	}
-	ctx->flags &= ~FS_WRITE_PATH_FL;
+	ctx->flags &= ~FS_CTX_HAS_BOUNCE_BUFFER_FL;
 	return ctx;
 }
 EXPORT_SYMBOL(fscrypt_get_ctx);
···
 	FS_ENCRYPT,
 } fscrypt_direction_t;
 
-static int do_page_crypto(struct inode *inode,
-			fscrypt_direction_t rw, pgoff_t index,
+static int do_page_crypto(const struct inode *inode,
+			fscrypt_direction_t rw, u64 lblk_num,
 			struct page *src_page, struct page *dest_page,
+			unsigned int len, unsigned int offs,
 			gfp_t gfp_flags)
 {
 	struct {
···
 	struct fscrypt_info *ci = inode->i_crypt_info;
 	struct crypto_skcipher *tfm = ci->ci_ctfm;
 	int res = 0;
+
+	BUG_ON(len == 0);
 
 	req = skcipher_request_alloc(tfm, gfp_flags);
 	if (!req) {
···
 		page_crypt_complete, &ecr);
 
 	BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE);
-	xts_tweak.index = cpu_to_le64(index);
+	xts_tweak.index = cpu_to_le64(lblk_num);
 	memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding));
 
 	sg_init_table(&dst, 1);
-	sg_set_page(&dst, dest_page, PAGE_SIZE, 0);
+	sg_set_page(&dst, dest_page, len, offs);
 	sg_init_table(&src, 1);
-	sg_set_page(&src, src_page, PAGE_SIZE, 0);
-	skcipher_request_set_crypt(req, &src, &dst, PAGE_SIZE, &xts_tweak);
+	sg_set_page(&src, src_page, len, offs);
+	skcipher_request_set_crypt(req, &src, &dst, len, &xts_tweak);
 	if (rw == FS_DECRYPT)
 		res = crypto_skcipher_decrypt(req);
 	else
···
 	ctx->w.bounce_page = mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
 	if (ctx->w.bounce_page == NULL)
 		return ERR_PTR(-ENOMEM);
-	ctx->flags |= FS_WRITE_PATH_FL;
+	ctx->flags |= FS_CTX_HAS_BOUNCE_BUFFER_FL;
 	return ctx->w.bounce_page;
 }
 
 /**
  * fscypt_encrypt_page() - Encrypts a page
- * @inode:          The inode for which the encryption should take place
- * @plaintext_page: The page to encrypt. Must be locked.
- * @gfp_flags:      The gfp flag for memory allocation
+ * @inode:     The inode for which the encryption should take place
+ * @page:      The page to encrypt. Must be locked for bounce-page
+ *             encryption.
+ * @len:       Length of data to encrypt in @page and encrypted
+ *             data in returned page.
+ * @offs:      Offset of data within @page and returned
+ *             page holding encrypted data.
+ * @lblk_num:  Logical block number. This must be unique for multiple
+ *             calls with same inode, except when overwriting
+ *             previously written data.
+ * @gfp_flags: The gfp flag for memory allocation
  *
- * Allocates a ciphertext page and encrypts plaintext_page into it using the ctx
- * encryption context.
+ * Encrypts @page using the ctx encryption context. Performs encryption
+ * either in-place or into a newly allocated bounce page.
+ * Called on the page write path.
  *
- * Called on the page write path.  The caller must call
+ * Bounce page allocation is the default.
+ * In this case, the contents of @page are encrypted and stored in an
+ * allocated bounce page. @page has to be locked and the caller must call
  * fscrypt_restore_control_page() on the returned ciphertext page to
  * release the bounce buffer and the encryption context.
  *
- * Return: An allocated page with the encrypted content on success. Else, an
+ * In-place encryption is used by setting the FS_CFLG_OWN_PAGES flag in
+ * fscrypt_operations. Here, the input-page is returned with its content
+ * encrypted.
+ *
+ * Return: A page with the encrypted content on success. Else, an
  * error value or NULL.
  */
-struct page *fscrypt_encrypt_page(struct inode *inode,
-				struct page *plaintext_page, gfp_t gfp_flags)
+struct page *fscrypt_encrypt_page(const struct inode *inode,
+				struct page *page,
+				unsigned int len,
+				unsigned int offs,
+				u64 lblk_num, gfp_t gfp_flags)
+
 {
 	struct fscrypt_ctx *ctx;
-	struct page *ciphertext_page = NULL;
+	struct page *ciphertext_page = page;
 	int err;
 
-	BUG_ON(!PageLocked(plaintext_page));
+	BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0);
+
+	if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) {
+		/* with inplace-encryption we just encrypt the page */
+		err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
+					page, ciphertext_page,
+					len, offs, gfp_flags);
+		if (err)
+			return ERR_PTR(err);
+
+		return ciphertext_page;
+	}
+
+	BUG_ON(!PageLocked(page));
 
 	ctx = fscrypt_get_ctx(inode, gfp_flags);
 	if (IS_ERR(ctx))
···
 	if (IS_ERR(ciphertext_page))
 		goto errout;
 
-	ctx->w.control_page = plaintext_page;
-	err = do_page_crypto(inode, FS_ENCRYPT, plaintext_page->index,
-					plaintext_page, ciphertext_page,
-					gfp_flags);
+	ctx->w.control_page = page;
+	err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
+					page, ciphertext_page,
+					len, offs, gfp_flags);
 	if (err) {
 		ciphertext_page = ERR_PTR(err);
 		goto errout;
···
 EXPORT_SYMBOL(fscrypt_encrypt_page);
 
 /**
- * f2crypt_decrypt_page() - Decrypts a page in-place
- * @page: The page to decrypt. Must be locked.
+ * fscrypt_decrypt_page() - Decrypts a page in-place
+ * @inode:     The corresponding inode for the page to decrypt.
+ * @page:      The page to decrypt. Must be locked in case
+ *             it is a writeback page (FS_CFLG_OWN_PAGES unset).
+ * @len:       Number of bytes in @page to be decrypted.
+ * @offs:      Start of data in @page.
+ * @lblk_num:  Logical block number.
  *
  * Decrypts page in-place using the ctx encryption context.
  *
···
  *
  * Return: Zero on success, non-zero otherwise.
  */
-int fscrypt_decrypt_page(struct page *page)
+int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
+			unsigned int len, unsigned int offs, u64 lblk_num)
 {
-	BUG_ON(!PageLocked(page));
+	if (!(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES))
+		BUG_ON(!PageLocked(page));
 
-	return do_page_crypto(page->mapping->host,
-			FS_DECRYPT, page->index, page, page, GFP_NOFS);
+	return do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page, len,
+			offs, GFP_NOFS);
 }
 EXPORT_SYMBOL(fscrypt_decrypt_page);
 
-int fscrypt_zeroout_range(struct inode *inode, pgoff_t lblk,
+int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 				sector_t pblk, unsigned int len)
 {
 	struct fscrypt_ctx *ctx;
···
 	while (len--) {
 		err = do_page_crypto(inode, FS_ENCRYPT, lblk,
 					ZERO_PAGE(0), ciphertext_page,
-					GFP_NOFS);
+					PAGE_SIZE, 0, GFP_NOFS);
 		if (err)
 			goto errout;
 
···
 
 	bio_for_each_segment_all(bv, bio, i) {
 		struct page *page = bv->bv_page;
-		int ret = fscrypt_decrypt_page(page);
+		int ret = fscrypt_decrypt_page(page->mapping->host, page,
+				PAGE_SIZE, 0, page->index);
 
 		if (ret) {
 			WARN_ON_ONCE(1);
···
 
 /**
  * fscrypt_initialize() - allocate major buffers for fs encryption.
+ * @cop_flags:  fscrypt operations flags
  *
  * We only call this when we start accessing encrypted files, since it
  * results in memory getting allocated that wouldn't otherwise be used.
  *
  * Return: Zero on success, non-zero otherwise.
  */
-int fscrypt_initialize(void)
+int fscrypt_initialize(unsigned int cop_flags)
 {
 	int i, res = -ENOMEM;
 
-	if (fscrypt_bounce_page_pool)
+	/*
+	 * No need to allocate a bounce page pool if there already is one or
+	 * this FS won't use it.
+	 */
+	if (cop_flags & FS_CFLG_OWN_PAGES || fscrypt_bounce_page_pool)
 		return 0;
 
 	mutex_lock(&fscrypt_init_mutex);
···
 	mutex_unlock(&fscrypt_init_mutex);
 	return res;
 }
-EXPORT_SYMBOL(fscrypt_initialize);
 
 /**
  * fscrypt_init() - Set up for fs encryption.

fs/crypto/fname.c

···
 
 #include <linux/scatterlist.h>
 #include <linux/ratelimit.h>
-#include <linux/fscrypto.h>
+#include "fscrypt_private.h"
 
 /**
  * fname_crypt_complete() - completion callback for filename crypto
···
 	return cp - dst;
 }
 
-u32 fscrypt_fname_encrypted_size(struct inode *inode, u32 ilen)
+u32 fscrypt_fname_encrypted_size(const struct inode *inode, u32 ilen)
 {
 	int padding = 32;
 	struct fscrypt_info *ci = inode->i_crypt_info;
···
  * Allocates an output buffer that is sufficient for the crypto operation
  * specified by the context and the direction.
  */
-int fscrypt_fname_alloc_buffer(struct inode *inode,
+int fscrypt_fname_alloc_buffer(const struct inode *inode,
 				u32 ilen, struct fscrypt_str *crypto_str)
 {
 	unsigned int olen = fscrypt_fname_encrypted_size(inode, ilen);
···
 		fname->disk_name.len = iname->len;
 		return 0;
 	}
-	ret = get_crypt_info(dir);
+	ret = fscrypt_get_crypt_info(dir);
 	if (ret && ret != -EOPNOTSUPP)
 		return ret;
 

fs/crypto/fscrypt_private.h

···
+/*
+ * fscrypt_private.h
+ *
+ * Copyright (C) 2015, Google, Inc.
+ *
+ * This contains encryption key functions.
+ *
+ * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
+ */
+
+#ifndef _FSCRYPT_PRIVATE_H
+#define _FSCRYPT_PRIVATE_H
+
+#include <linux/fscrypto.h>
+
+#define FS_FNAME_CRYPTO_DIGEST_SIZE	32
+
+/* Encryption parameters */
+#define FS_XTS_TWEAK_SIZE		16
+#define FS_AES_128_ECB_KEY_SIZE		16
+#define FS_AES_256_GCM_KEY_SIZE		32
+#define FS_AES_256_CBC_KEY_SIZE		32
+#define FS_AES_256_CTS_KEY_SIZE		32
+#define FS_AES_256_XTS_KEY_SIZE		64
+#define FS_MAX_KEY_SIZE			64
+
+#define FS_KEY_DESC_PREFIX		"fscrypt:"
+#define FS_KEY_DESC_PREFIX_SIZE		8
+
+#define FS_KEY_DERIVATION_NONCE_SIZE		16
+
+/**
+ * Encryption context for inode
+ *
+ * Protector format:
+ *  1 byte: Protector format (1 = this version)
+ *  1 byte: File contents encryption mode
+ *  1 byte: File names encryption mode
+ *  1 byte: Flags
+ *  8 bytes: Master Key descriptor
+ *  16 bytes: Encryption Key derivation nonce
+ */
+struct fscrypt_context {
+	u8 format;
+	u8 contents_encryption_mode;
+	u8 filenames_encryption_mode;
+	u8 flags;
+	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
+	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
+} __packed;
+
+#define FS_ENCRYPTION_CONTEXT_FORMAT_V1		1
+
+/* This is passed in from userspace into the kernel keyring */
+struct fscrypt_key {
+	u32 mode;
+	u8 raw[FS_MAX_KEY_SIZE];
+	u32 size;
+} __packed;
+
+/*
+ * A pointer to this structure is stored in the file system's in-core
+ * representation of an inode.
+ */
+struct fscrypt_info {
+	u8 ci_data_mode;
+	u8 ci_filename_mode;
+	u8 ci_flags;
+	struct crypto_skcipher *ci_ctfm;
+	struct key *ci_keyring_key;
+	u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
+};
+
+#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL		0x00000001
+#define FS_CTX_HAS_BOUNCE_BUFFER_FL		0x00000002
+
+struct fscrypt_completion_result {
+	struct completion completion;
+	int res;
+};
+
+#define DECLARE_FS_COMPLETION_RESULT(ecr) \
+	struct fscrypt_completion_result ecr = { \
+		COMPLETION_INITIALIZER((ecr).completion), 0 }
+
+
+/* crypto.c */
+int fscrypt_initialize(unsigned int cop_flags);
+
+/* keyinfo.c */
+extern int fscrypt_get_crypt_info(struct inode *);
+
+#endif /* _FSCRYPT_PRIVATE_H */

fs/crypto/keyinfo.c

···
 
 #include <keys/user-type.h>
 #include <linux/scatterlist.h>
-#include <linux/fscrypto.h>
+#include "fscrypt_private.h"
 
 static void derive_crypt_complete(struct crypto_async_request *req, int rc)
 {
···
 	kmem_cache_free(fscrypt_info_cachep, ci);
 }
 
-int get_crypt_info(struct inode *inode)
+int fscrypt_get_crypt_info(struct inode *inode)
 {
 	struct fscrypt_info *crypt_info;
 	struct fscrypt_context ctx;
···
 	u8 *raw_key = NULL;
 	int res;
 
-	res = fscrypt_initialize();
+	res = fscrypt_initialize(inode->i_sb->s_cop->flags);
 	if (res)
 		return res;
 
···
 		 (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
 					       (1 << KEY_FLAG_REVOKED) |
 					       (1 << KEY_FLAG_DEAD)))))
-		return get_crypt_info(inode);
+		return fscrypt_get_crypt_info(inode);
 	return 0;
 }
 EXPORT_SYMBOL(fscrypt_get_encryption_info);

fs/crypto/policy.c

···
 
 #include <linux/random.h>
 #include <linux/string.h>
-#include <linux/fscrypto.h>
 #include <linux/mount.h>
+#include "fscrypt_private.h"
 
 static int inode_has_encryption_context(struct inode *inode)
 {
···
 	return inode->i_sb->s_cop->set_context(inode, &ctx, sizeof(ctx), NULL);
 }
 
-int fscrypt_process_policy(struct file *filp,
-				const struct fscrypt_policy *policy)
+int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
 {
+	struct fscrypt_policy policy;
 	struct inode *inode = file_inode(filp);
 	int ret;
+
+	if (copy_from_user(&policy, arg, sizeof(policy)))
+		return -EFAULT;
 
 	if (!inode_owner_or_capable(inode))
 		return -EACCES;
 
-	if (policy->version != 0)
+	if (policy.version != 0)
 		return -EINVAL;
 
 	ret = mnt_want_write_file(filp);
···
 			ret = -ENOTEMPTY;
 		else
 			ret = create_encryption_context_from_policy(inode,
-								    policy);
+								    &policy);
 	} else if (!is_encryption_context_consistent_with_policy(inode,
-								 policy)) {
+								 &policy)) {
 		printk(KERN_WARNING
 		       "%s: Policy inconsistent with encryption context\n",
 		       __func__);
···
 	mnt_drop_write_file(filp);
 	return ret;
 }
-EXPORT_SYMBOL(fscrypt_process_policy);
+EXPORT_SYMBOL(fscrypt_ioctl_set_policy);
 
-int fscrypt_get_policy(struct inode *inode, struct fscrypt_policy *policy)
+int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
 {
+	struct inode *inode = file_inode(filp);
 	struct fscrypt_context ctx;
+	struct fscrypt_policy policy;
 	int res;
 
 	if (!inode->i_sb->s_cop->get_context ||
···
 	if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1)
 		return -EINVAL;
 
-	policy->version = 0;
-	policy->contents_encryption_mode = ctx.contents_encryption_mode;
-	policy->filenames_encryption_mode = ctx.filenames_encryption_mode;
-	policy->flags = ctx.flags;
-	memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor,
+	policy.version = 0;
+	policy.contents_encryption_mode = ctx.contents_encryption_mode;
+	policy.filenames_encryption_mode = ctx.filenames_encryption_mode;
+	policy.flags = ctx.flags;
+	memcpy(policy.master_key_descriptor, ctx.master_key_descriptor,
 				FS_KEY_DESCRIPTOR_SIZE);
+
+	if (copy_to_user(arg, &policy, sizeof(policy)))
+		return -EFAULT;
 	return 0;
 }
-EXPORT_SYMBOL(fscrypt_get_policy);
+EXPORT_SYMBOL(fscrypt_ioctl_get_policy);
 
 int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
 {

fs/dax.c

···
 #include <linux/iomap.h>
 #include "internal.h"
 
-/*
- * We use lowest available bit in exceptional entry for locking, other two
- * bits to determine entry type. In total 3 special bits.
- */
-#define RADIX_DAX_SHIFT	(RADIX_TREE_EXCEPTIONAL_SHIFT + 3)
-#define RADIX_DAX_PTE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
-#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
-#define RADIX_DAX_TYPE_MASK (RADIX_DAX_PTE | RADIX_DAX_PMD)
-#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_TYPE_MASK)
-#define RADIX_DAX_SECTOR(entry) (((unsigned long)entry >> RADIX_DAX_SHIFT))
-#define RADIX_DAX_ENTRY(sector, pmd) ((void *)((unsigned long)sector << \
-		RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE) | \
-		RADIX_TREE_EXCEPTIONAL_ENTRY))
-
 /* We choose 4096 entries - same as per-zone page wait tables */
 #define DAX_WAIT_TABLE_BITS 12
 #define DAX_WAIT_TABLE_ENTRIES (1 << DAX_WAIT_TABLE_BITS)
 
-wait_queue_head_t wait_table[DAX_WAIT_TABLE_ENTRIES];
+static wait_queue_head_t wait_table[DAX_WAIT_TABLE_ENTRIES];
 
 static int __init init_dax_wait_table(void)
 {
···
 	return 0;
 }
 fs_initcall(init_dax_wait_table);
-
-static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping,
-					      pgoff_t index)
-{
-	unsigned long hash = hash_long((unsigned long)mapping ^ index,
-				       DAX_WAIT_TABLE_BITS);
-	return wait_table + hash;
-}
 
 static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax)
 {
···
 	blk_queue_exit(bdev->bd_queue);
 }
 
+static int dax_is_pmd_entry(void *entry)
+{
+	return (unsigned long)entry & RADIX_DAX_PMD;
+}
+
+static int dax_is_pte_entry(void *entry)
+{
+	return !((unsigned long)entry & RADIX_DAX_PMD);
+}
+
+static int dax_is_zero_entry(void *entry)
+{
+	return (unsigned long)entry & RADIX_DAX_HZP;
+}
+
+static int dax_is_empty_entry(void *entry)
+{
+	return (unsigned long)entry & RADIX_DAX_EMPTY;
+}
+
 struct page *read_dax_sector(struct block_device *bdev, sector_t n)
 {
 	struct page *page = alloc_pages(GFP_KERNEL, 0);
···
 	return page;
 }
 
-static bool buffer_written(struct buffer_head *bh)
-{
-	return buffer_mapped(bh) && !buffer_unwritten(bh);
-}
-
-/*
- * When ext4 encounters a hole, it returns without modifying the buffer_head
- * which means that we can't trust b_size.  To cope with this, we set b_state
- * to 0 before calling get_block and, if any bit is set, we know we can trust
- * b_size.  Unfortunate, really, since ext4 knows precisely how long a hole is
- * and would save us time calling get_block repeatedly.
- */
-static bool buffer_size_valid(struct buffer_head *bh)
-{
-	return bh->b_state != 0;
-}
-
-
-static sector_t to_sector(const struct buffer_head *bh,
-		const struct inode *inode)
-{
-	sector_t sector = bh->b_blocknr << (inode->i_blkbits - 9);
-
-	return sector;
-}
-
-static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
-		      loff_t start, loff_t end, get_block_t get_block,
-		      struct buffer_head *bh)
-{
-	loff_t pos = start, max = start, bh_max = start;
-	bool hole = false;
-	struct block_device *bdev = NULL;
-	int rw = iov_iter_rw(iter), rc;
-	long map_len = 0;
-	struct blk_dax_ctl dax = {
-		.addr = ERR_PTR(-EIO),
-	};
-	unsigned blkbits = inode->i_blkbits;
-	sector_t file_blks = (i_size_read(inode) + (1 << blkbits) - 1)
-								>> blkbits;
-
-	if (rw == READ)
-		end = min(end, i_size_read(inode));
-
-	while (pos < end) {
-		size_t len;
-		if (pos == max) {
-			long page = pos >> PAGE_SHIFT;
-			sector_t block = page << (PAGE_SHIFT - blkbits);
-			unsigned first = pos - (block << blkbits);
-			long size;
-
-			if (pos == bh_max) {
-				bh->b_size = PAGE_ALIGN(end - pos);
-				bh->b_state = 0;
-				rc = get_block(inode, block, bh, rw == WRITE);
-				if (rc)
-					break;
-				if (!buffer_size_valid(bh))
-					bh->b_size = 1 << blkbits;
-				bh_max = pos - first + bh->b_size;
-				bdev = bh->b_bdev;
-				/*
-				 * We allow uninitialized buffers for writes
-				 * beyond EOF as those cannot race with faults
-				 */
-				WARN_ON_ONCE(
-					(buffer_new(bh) && block < file_blks) ||
-					(rw == WRITE && buffer_unwritten(bh)));
-			} else {
-				unsigned done = bh->b_size -
-						(bh_max - (pos - first));
-				bh->b_blocknr += done >> blkbits;
-				bh->b_size -= done;
-			}
-
-			hole = rw == READ && !buffer_written(bh);
-			if (hole) {
-				size = bh->b_size - first;
-			} else {
-				dax_unmap_atomic(bdev, &dax);
-				dax.sector = to_sector(bh, inode);
-				dax.size = bh->b_size;
-				map_len = dax_map_atomic(bdev, &dax);
-				if (map_len < 0) {
-					rc = map_len;
-					break;
-				}
-				dax.addr += first;
-				size = map_len - first;
-			}
-			/*
-			 * pos + size is one past the last offset for IO,
-			 * so pos + size can overflow loff_t at extreme offsets.
-			 * Cast to u64 to catch this and get the true minimum.
-			 */
-			max = min_t(u64, pos + size, end);
-		}
-
-		if (iov_iter_rw(iter) == WRITE) {
-			len = copy_from_iter_pmem(dax.addr, max - pos, iter);
-		} else if (!hole)
-			len = copy_to_iter((void __force *) dax.addr, max - pos,
-					iter);
-		else
-			len = iov_iter_zero(max - pos, iter);
-
-		if (!len) {
-			rc = -EFAULT;
-			break;
-		}
-
-		pos += len;
-		if (!IS_ERR(dax.addr))
-			dax.addr += len;
-	}
-
-	dax_unmap_atomic(bdev, &dax);
-
-	return (pos == start) ? rc : pos - start;
-}
-
-/**
- * dax_do_io - Perform I/O to a DAX file
- * @iocb: The control block for this I/O
- * @inode: The file which the I/O is directed at
- * @iter: The addresses to do I/O from or to
- * @get_block: The filesystem method used to translate file offsets to blocks
- * @end_io: A filesystem callback for I/O completion
- * @flags: See below
- *
- * This function uses the same locking scheme as do_blockdev_direct_IO:
- * If @flags has DIO_LOCKING set, we assume that the i_mutex is held by the
- * caller for writes.  For reads, we take and release the i_mutex ourselves.
- * If DIO_LOCKING is not set, the filesystem takes care of its own locking.
- * As with do_blockdev_direct_IO(), we increment i_dio_count while the I/O
- * is in progress.
- */
-ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode,
-		  struct iov_iter *iter, get_block_t get_block,
-		  dio_iodone_t end_io, int flags)
-{
-	struct buffer_head bh;
-	ssize_t retval = -EINVAL;
-	loff_t pos = iocb->ki_pos;
-	loff_t end = pos + iov_iter_count(iter);
-
-	memset(&bh, 0, sizeof(bh));
-	bh.b_bdev = inode->i_sb->s_bdev;
-
-	if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ)
-		inode_lock(inode);
-
-	/* Protects against truncate */
-	if (!(flags & DIO_SKIP_DIO_COUNT))
-		inode_dio_begin(inode);
-
-	retval = dax_io(inode, iter, pos, end, get_block, &bh);
-
-	if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ)
-		inode_unlock(inode);
-
-	if (end_io) {
-		int err;
-
-		err = end_io(iocb, pos, retval, bh.b_private);
-		if (err)
-			retval = err;
-	}
-
-	if (!(flags & DIO_SKIP_DIO_COUNT))
-		inode_dio_end(inode);
-	return retval;
-}
-EXPORT_SYMBOL_GPL(dax_do_io);
-
 /*
  * DAX radix tree locking
  */
 struct exceptional_entry_key {
 	struct address_space *mapping;
-	unsigned long index;
+	pgoff_t entry_start;
 };
 
 struct wait_exceptional_entry_queue {
 	wait_queue_t wait;
 	struct exceptional_entry_key key;
 };
+
+static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping,
+		pgoff_t index, void *entry, struct exceptional_entry_key *key)
+{
+	unsigned long hash;
+
+	/*
+	 * If 'entry' is a PMD, align the 'index' that we use for the wait
+	 * queue to the start of that PMD.  This ensures that all offsets in
+	 * the range covered by the PMD map to the same bit lock.
+	 */
+	if (dax_is_pmd_entry(entry))
+		index &= ~((1UL << (PMD_SHIFT - PAGE_SHIFT)) - 1);
+
+	key->mapping = mapping;
+	key->entry_start = index;
+
+	hash = hash_long((unsigned long)mapping ^ index, DAX_WAIT_TABLE_BITS);
+	return wait_table + hash;
+}
 
 static int wake_exceptional_entry_func(wait_queue_t *wait, unsigned int mode,
 				       int sync, void *keyp)
···
 		container_of(wait, struct wait_exceptional_entry_queue, wait);
 
 	if (key->mapping != ewait->key.mapping ||
-	    key->index != ewait->key.index)
+	    key->entry_start != ewait->key.entry_start)
 		return 0;
 	return autoremove_wake_function(wait, mode, sync, NULL);
 }
···
 static void *get_unlocked_mapping_entry(struct address_space *mapping,
 					pgoff_t index, void ***slotp)
 {
-	void *ret, **slot;
+	void *entry, **slot;
 	struct wait_exceptional_entry_queue ewait;
-	wait_queue_head_t *wq = dax_entry_waitqueue(mapping, index);
+	wait_queue_head_t *wq;
 
 	init_wait(&ewait.wait);
 	ewait.wait.func = wake_exceptional_entry_func;
-	ewait.key.mapping = mapping;
-	ewait.key.index = index;
 
 	for (;;) {
-		ret = __radix_tree_lookup(&mapping->page_tree, index, NULL,
+		entry = __radix_tree_lookup(&mapping->page_tree, index, NULL,
 					  &slot);
-		if (!ret || !radix_tree_exceptional_entry(ret) ||
+		if (!entry || !radix_tree_exceptional_entry(entry) ||
 		    !slot_locked(mapping, slot)) {
 			if (slotp)
 				*slotp = slot;
-			return ret;
+			return entry;
 		}
+
+		wq = dax_entry_waitqueue(mapping, index, entry, &ewait.key);
 		prepare_to_wait_exclusive(wq, &ewait.wait,
 					  TASK_UNINTERRUPTIBLE);
 		spin_unlock_irq(&mapping->tree_lock);
···
 		finish_wait(wq, &ewait.wait);
 		spin_lock_irq(&mapping->tree_lock);
 	}
-}
-
-/*
- * Find radix tree entry at given index. If it points to a page, return with
- * the page locked. If it points to the exceptional entry, return with the
- * radix tree entry locked. If the radix tree doesn't contain given index,
- * create empty exceptional entry for the index and return with it locked.
- *
- * Note: Unlike filemap_fault() we don't honor FAULT_FLAG_RETRY flags. For
- * persistent memory the benefit is doubtful. We can add that later if we can
- * show it helps.
- */
-static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index)
-{
-	void *ret, **slot;
-
-restart:
-	spin_lock_irq(&mapping->tree_lock);
-	ret = get_unlocked_mapping_entry(mapping, index, &slot);
-	/* No entry for given index? Make sure radix tree is big enough. */
-	if (!ret) {
-		int err;
-
-		spin_unlock_irq(&mapping->tree_lock);
-		err = radix_tree_preload(
-				mapping_gfp_mask(mapping) & ~__GFP_HIGHMEM);
-		if (err)
-			return ERR_PTR(err);
-		ret = (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY |
-			       RADIX_DAX_ENTRY_LOCK);
-		spin_lock_irq(&mapping->tree_lock);
-		err = radix_tree_insert(&mapping->page_tree, index, ret);
-		radix_tree_preload_end();
-		if (err) {
-			spin_unlock_irq(&mapping->tree_lock);
-			/* Someone already created the entry? */
-			if (err == -EEXIST)
-				goto restart;
-			return ERR_PTR(err);
-		}
-		/* Good, we have inserted empty locked entry into the tree. */
-		mapping->nrexceptional++;
-		spin_unlock_irq(&mapping->tree_lock);
-		return ret;
-	}
-	/* Normal page in radix tree? */
-	if (!radix_tree_exceptional_entry(ret)) {
-		struct page *page = ret;
-
-		get_page(page);
-		spin_unlock_irq(&mapping->tree_lock);
-		lock_page(page);
-		/* Page got truncated? Retry... */
-		if (unlikely(page->mapping != mapping)) {
-			unlock_page(page);
-			put_page(page);
-			goto restart;
-		}
-		return page;
-	}
-	ret = lock_slot(mapping, slot);
-	spin_unlock_irq(&mapping->tree_lock);
-	return ret;
-}
-
-void dax_wake_mapping_entry_waiter(struct address_space *mapping,
-				   pgoff_t index, bool wake_all)
-{
-	wait_queue_head_t *wq = dax_entry_waitqueue(mapping, index);
-
-	/*
-	 * Checking for locked entry and prepare_to_wait_exclusive() happens
-	 * under mapping->tree_lock, ditto for entry handling in our callers.
-	 * So at this point all tasks that could have seen our entry locked
-	 * must be in the waitqueue and the following check will see them.
-	 */
-	if (waitqueue_active(wq)) {
-		struct exceptional_entry_key key;
-
-		key.mapping = mapping;
-		key.index = index;
-		__wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key);
-	}
-}
-
-void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index)
-{
-	void *ret, **slot;
-
-	spin_lock_irq(&mapping->tree_lock);
-	ret = __radix_tree_lookup(&mapping->page_tree, index, NULL, &slot);
-	if (WARN_ON_ONCE(!ret || !radix_tree_exceptional_entry(ret) ||
-			 !slot_locked(mapping, slot))) {
-		spin_unlock_irq(&mapping->tree_lock);
-		return;
-	}
-	unlock_slot(mapping, slot);
-	spin_unlock_irq(&mapping->tree_lock);
-	dax_wake_mapping_entry_waiter(mapping, index, false);
 }
 
 static void put_locked_mapping_entry(struct address_space *mapping,
···
 		return;
 
 	/* We have to wake up next waiter for the radix tree entry lock */
-	dax_wake_mapping_entry_waiter(mapping, index, false);
+	dax_wake_mapping_entry_waiter(mapping, index, entry, false);
+}
+
+/*
+ * Find radix tree entry at given index. If it points to a page, return with
+ * the page locked. If it points to the exceptional entry, return with the
+ * radix tree entry locked. If the radix tree doesn't contain given index,
+ * create empty exceptional entry for the index and return with it locked.
+ *
+ * When requesting an entry with size RADIX_DAX_PMD, grab_mapping_entry() will
+ * either return that locked entry or will return an error.  This error will
+ * happen if there are any 4k entries (either zero pages or DAX entries)
+ * within the 2MiB range that we are requesting.
+ *
+ * We always favor 4k entries over 2MiB entries. There isn't a flow where we
+ * evict 4k entries in order to 'upgrade' them to a 2MiB entry.  A 2MiB
+ * insertion will fail if it finds any 4k entries already in the tree, and a
+ * 4k insertion will cause an existing 2MiB entry to be unmapped and
+ * downgraded to 4k entries.  This happens for both 2MiB huge zero pages as
+ * well as 2MiB empty entries.
+ *
+ * The exception to this downgrade path is for 2MiB DAX PMD entries that have
+ * real storage backing them.  We will leave these real 2MiB DAX entries in
+ * the tree, and PTE writes will simply dirty the entire 2MiB DAX entry.
+ *
+ * Note: Unlike filemap_fault() we don't honor FAULT_FLAG_RETRY flags. For
+ * persistent memory the benefit is doubtful. We can add that later if we can
+ * show it helps.
+ */
+static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
+		unsigned long size_flag)
+{
+	bool pmd_downgrade = false; /* splitting 2MiB entry into 4k entries? */
+	void *entry, **slot;
+
+restart:
+	spin_lock_irq(&mapping->tree_lock);
+	entry = get_unlocked_mapping_entry(mapping, index, &slot);
+
+	if (entry) {
+		if (size_flag & RADIX_DAX_PMD) {
+			if (!radix_tree_exceptional_entry(entry) ||
+			    dax_is_pte_entry(entry)) {
+				put_unlocked_mapping_entry(mapping, index,
+						entry);
+				entry = ERR_PTR(-EEXIST);
+				goto out_unlock;
+			}
+		} else { /* trying to grab a PTE entry */
+			if (radix_tree_exceptional_entry(entry) &&
+			    dax_is_pmd_entry(entry) &&
+			    (dax_is_zero_entry(entry) ||
+			     dax_is_empty_entry(entry))) {
+				pmd_downgrade = true;
+			}
+		}
+	}
+
+	/* No entry for given index? Make sure radix tree is big enough. */
+	if (!entry || pmd_downgrade) {
+		int err;
+
+		if (pmd_downgrade) {
+			/*
+			 * Make sure 'entry' remains valid while we drop
+			 * mapping->tree_lock.
+			 */
+			entry = lock_slot(mapping, slot);
+		}
+
+		spin_unlock_irq(&mapping->tree_lock);
+		/*
+		 * Besides huge zero pages the only other thing that gets
+		 * downgraded are empty entries which don't need to be
+		 * unmapped.
+		 */
+		if (pmd_downgrade && dax_is_zero_entry(entry))
+			unmap_mapping_range(mapping,
+				(index << PAGE_SHIFT) & PMD_MASK, PMD_SIZE, 0);
+
+		err = radix_tree_preload(
+				mapping_gfp_mask(mapping) & ~__GFP_HIGHMEM);
+		if (err) {
+			if (pmd_downgrade)
+				put_locked_mapping_entry(mapping, index, entry);
+			return ERR_PTR(err);
+		}
+		spin_lock_irq(&mapping->tree_lock);
+
+		if (pmd_downgrade) {
+			radix_tree_delete(&mapping->page_tree, index);
+			mapping->nrexceptional--;
+			dax_wake_mapping_entry_waiter(mapping, index, entry,
+					true);
+		}
+
+		entry = dax_radix_locked_entry(0, size_flag | RADIX_DAX_EMPTY);
+
+		err = __radix_tree_insert(&mapping->page_tree, index,
+				dax_radix_order(entry), entry);
+		radix_tree_preload_end();
+		if (err) {
+			spin_unlock_irq(&mapping->tree_lock);
+			/*
+			 * Someone already created the entry?  This is a
+			 * normal failure when inserting PMDs in a range
+			 * that already contains PTEs.  In that case we want
+			 * to return -EEXIST immediately.
+			 */
+			if (err == -EEXIST && !(size_flag & RADIX_DAX_PMD))
+				goto restart;
+			/*
+			 * Our insertion of a DAX PMD entry failed, most
+			 * likely because it collided with a PTE sized entry
+			 * at a different index in the PMD range.  We haven't
+			 * inserted anything into the radix tree and have no
+			 * waiters to wake.
+			 */
+			return ERR_PTR(err);
+		}
+		/* Good, we have inserted empty locked entry into the tree. */
+		mapping->nrexceptional++;
+		spin_unlock_irq(&mapping->tree_lock);
+		return entry;
+	}
+	/* Normal page in radix tree? */
+	if (!radix_tree_exceptional_entry(entry)) {
+		struct page *page = entry;
+
+		get_page(page);
+		spin_unlock_irq(&mapping->tree_lock);
+		lock_page(page);
+		/* Page got truncated? Retry... */
+		if (unlikely(page->mapping != mapping)) {
+			unlock_page(page);
+			put_page(page);
+			goto restart;
+		}
+		return page;
+	}
+	entry = lock_slot(mapping, slot);
+ out_unlock:
+	spin_unlock_irq(&mapping->tree_lock);
+	return entry;
+}
+
+/*
+ * We do not necessarily hold the mapping->tree_lock when we call this
+ * function so it is possible that 'entry' is no longer a valid item in the
+ * radix tree.  This is okay because all we really need to do is to find the
+ * correct waitqueue where tasks might be waiting for that old 'entry' and
+ * wake them.
+ */
+void dax_wake_mapping_entry_waiter(struct address_space *mapping,
+		pgoff_t index, void *entry, bool wake_all)
+{
+	struct exceptional_entry_key key;
+	wait_queue_head_t *wq;
+
+	wq = dax_entry_waitqueue(mapping, index, entry, &key);
+
+	/*
+	 * Checking for locked entry and prepare_to_wait_exclusive() happens
+	 * under mapping->tree_lock, ditto for entry handling in our callers.
+	 * So at this point all tasks that could have seen our entry locked
+	 * must be in the waitqueue and the following check will see them.
+	 */
+	if (waitqueue_active(wq))
+		__wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key);
+}
+
+void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index)
+{
+	void *entry, **slot;
+
+	spin_lock_irq(&mapping->tree_lock);
+	entry = __radix_tree_lookup(&mapping->page_tree, index, NULL, &slot);
+	if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry) ||
+			 !slot_locked(mapping, slot))) {
+		spin_unlock_irq(&mapping->tree_lock);
+		return;
+	}
+	unlock_slot(mapping, slot);
+	spin_unlock_irq(&mapping->tree_lock);
+	dax_wake_mapping_entry_waiter(mapping, index, entry, false);
 }
 
 /*
···
 	radix_tree_delete(&mapping->page_tree, index);
 	mapping->nrexceptional--;
 	spin_unlock_irq(&mapping->tree_lock);
-	dax_wake_mapping_entry_waiter(mapping, index, true);
+	dax_wake_mapping_entry_waiter(mapping, index, entry, true);
 
 	return 1;
 }
···
 	return 0;
 }
 
-#define DAX_PMD_INDEX(page_index) (page_index & (PMD_MASK >> PAGE_SHIFT))
-
+/*
+ * By this point grab_mapping_entry() has ensured that we have a locked entry
+ * of the appropriate size so we don't have to worry about downgrading PMDs to
+ * PTEs.  If we happen to be trying to insert a PTE and there is a PMD
+ * already in the tree, we will skip the insertion and just dirty the PMD as
+ * appropriate.
+ */
 static void *dax_insert_mapping_entry(struct address_space *mapping,
 				      struct vm_fault *vmf,
-				      void *entry, sector_t sector)
+				      void *entry, sector_t sector,
+				      unsigned long flags)
 {
 	struct radix_tree_root *page_tree = &mapping->page_tree;
 	int error = 0;
···
 		error = radix_tree_preload(vmf->gfp_mask & ~__GFP_HIGHMEM);
 		if (error)
 			return ERR_PTR(error);
+	} else if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_HZP)) {
+		/* replacing huge zero page with PMD block mapping */
+		unmap_mapping_range(mapping,
+			(vmf->pgoff << PAGE_SHIFT) & PMD_MASK, PMD_SIZE, 0);
 	}
 
 	spin_lock_irq(&mapping->tree_lock);
-	new_entry = (void *)((unsigned long)RADIX_DAX_ENTRY(sector, false) |
-		       RADIX_DAX_ENTRY_LOCK);
+	new_entry = dax_radix_locked_entry(sector, flags);
+
 	if (hole_fill) {
 		__delete_from_page_cache(entry, NULL);
 		/* Drop pagecache reference */
 		put_page(entry);
-		error = radix_tree_insert(page_tree, index, new_entry);
+		error = __radix_tree_insert(page_tree, index,
+				dax_radix_order(new_entry), new_entry);
 		if (error) {
 			new_entry = ERR_PTR(error);
 			goto unlock;
 		}
 		mapping->nrexceptional++;
-	} else {
+	} else if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) {
+		/*
+		 * Only swap our new entry into the radix tree if the current
+		 * entry is a zero page or an empty entry.  If a normal PTE or
+		 * PMD entry is already in the tree, we leave it alone.  This
+		 * means that if we are trying to insert a PTE and the
+		 * existing entry is a PMD, we will just leave the PMD in the
+		 * tree and dirty it if necessary.
+		 */
 		struct radix_tree_node *node;
 		void **slot;
 		void *ret;
···
 		struct address_space *mapping, pgoff_t index, void *entry)
 {
 	struct radix_tree_root *page_tree = &mapping->page_tree;
-	int type = RADIX_DAX_TYPE(entry);
 	struct radix_tree_node *node;
 	struct blk_dax_ctl dax;
 	void **slot;
···
 	if (!radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))
 		goto unlock;
 
-	if (WARN_ON_ONCE(type != RADIX_DAX_PTE && type != RADIX_DAX_PMD)) {
+	if (WARN_ON_ONCE(dax_is_empty_entry(entry) ||
+				dax_is_zero_entry(entry))) {
 		ret = -EIO;
 		goto unlock;
 	}
 
-	dax.sector = RADIX_DAX_SECTOR(entry);
-	dax.size = (type == RADIX_DAX_PMD ? PMD_SIZE : PAGE_SIZE);
+	/*
+	 * Even if dax_writeback_mapping_range() was given a wbc->range_start
+	 * in the middle of a PMD, the 'index' we are given will be aligned to
+	 * the start index of the PMD, as will the sector we pull from
+	 * 'entry'.  This allows us to flush for PMD_SIZE and not have to
+	 * worry about partial PMD writebacks.
+	 */
+	dax.sector = dax_radix_sector(entry);
+	dax.size = PAGE_SIZE << dax_radix_order(entry);
 	spin_unlock_irq(&mapping->tree_lock);
 
 	/*
···
 		struct block_device *bdev, struct writeback_control *wbc)
 {
 	struct inode *inode = mapping->host;
-	pgoff_t start_index, end_index, pmd_index;
+	pgoff_t start_index, end_index;
 	pgoff_t indices[PAGEVEC_SIZE];
 	struct pagevec pvec;
 	bool done = false;
 	int i, ret = 0;
-	void *entry;
 
 	if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT))
 		return -EIO;
···
 
 	start_index = wbc->range_start >> PAGE_SHIFT;
 	end_index = wbc->range_end >> PAGE_SHIFT;
-	pmd_index = DAX_PMD_INDEX(start_index);
-
-	rcu_read_lock();
-	entry = radix_tree_lookup(&mapping->page_tree, pmd_index);
-	rcu_read_unlock();
-
-	/* see if the start of our range is covered by a PMD entry */
-	if (entry && RADIX_DAX_TYPE(entry) == RADIX_DAX_PMD)
-		start_index = pmd_index;
 
 	tag_pages_for_writeback(mapping, start_index, end_index);
 
···
 		return PTR_ERR(dax.addr);
 	dax_unmap_atomic(bdev, &dax);
 
-	ret = dax_insert_mapping_entry(mapping, vmf, entry, dax.sector);
+	ret = dax_insert_mapping_entry(mapping, vmf, entry, dax.sector, 0);
 	if (IS_ERR(ret))
 		return PTR_ERR(ret);
 	*entryp = ret;
 
 	return vm_insert_mixed(vma, vaddr, dax.pfn);
 }
-
-/**
- * dax_fault - handle a page fault on a DAX file
- * @vma: The virtual memory area where the fault occurred
- * @vmf: The description of the fault
- * @get_block: The filesystem method used to translate file offsets to blocks
- *
- * When a page fault occurs, filesystems may call this helper in their
- * fault handler for DAX files. dax_fault() assumes the caller has done all
- * the necessary locking for the page fault to proceed successfully.
- */
-int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
-			get_block_t get_block)
-{
-	struct file *file = vma->vm_file;
-	struct address_space *mapping = file->f_mapping;
-	struct inode *inode = mapping->host;
-	void *entry;
-	struct buffer_head bh;
-	unsigned long vaddr = (unsigned long)vmf->virtual_address;
-	unsigned blkbits = inode->i_blkbits;
-	sector_t block;
-	pgoff_t size;
-	int error;
-	int major = 0;
-
-	/*
-	 * Check whether offset isn't beyond end of file now. Caller is supposed
-	 * to hold locks serializing us with truncate / punch hole so this is
-	 * a reliable test.
-	 */
-	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	if (vmf->pgoff >= size)
-		return VM_FAULT_SIGBUS;
-
-	memset(&bh, 0, sizeof(bh));
-	block = (sector_t)vmf->pgoff << (PAGE_SHIFT - blkbits);
-	bh.b_bdev = inode->i_sb->s_bdev;
-	bh.b_size = PAGE_SIZE;
-
-	entry = grab_mapping_entry(mapping, vmf->pgoff);
-	if (IS_ERR(entry)) {
-		error = PTR_ERR(entry);
-		goto out;
-	}
-
-	error = get_block(inode, block, &bh, 0);
-	if (!error && (bh.b_size < PAGE_SIZE))
-		error = -EIO;		/* fs corruption? */
-	if (error)
-		goto unlock_entry;
-
-	if (vmf->cow_page) {
-		struct page *new_page = vmf->cow_page;
-		if (buffer_written(&bh))
-			error = copy_user_dax(bh.b_bdev, to_sector(&bh, inode),
-					bh.b_size, new_page, vaddr);
-		else
-			clear_user_highpage(new_page, vaddr);
-		if (error)
-			goto unlock_entry;
-		if (!radix_tree_exceptional_entry(entry)) {
-			vmf->page = entry;
-			return VM_FAULT_LOCKED;
-		}
-		vmf->entry = entry;
-		return VM_FAULT_DAX_LOCKED;
-	}
-
-	if (!buffer_mapped(&bh)) {
-		if (vmf->flags & FAULT_FLAG_WRITE) {
-			error = get_block(inode, block, &bh, 1);
-			count_vm_event(PGMAJFAULT);
-			mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
-			major = VM_FAULT_MAJOR;
-			if (!error && (bh.b_size < PAGE_SIZE))
-				error = -EIO;
-			if (error)
-				goto unlock_entry;
-		} else {
-			return dax_load_hole(mapping, entry, vmf);
-		}
-	}
-
-	/* Filesystem should not return unwritten buffers to us! */
-	WARN_ON_ONCE(buffer_unwritten(&bh) || buffer_new(&bh));
-	error = dax_insert_mapping(mapping, bh.b_bdev, to_sector(&bh, inode),
-			bh.b_size, &entry, vma, vmf);
- unlock_entry:
-	put_locked_mapping_entry(mapping, vmf->pgoff, entry);
- out:
-	if (error == -ENOMEM)
-		return VM_FAULT_OOM | major;
-	/* -EBUSY is fine, somebody else faulted on the same PTE */
-	if ((error < 0) && (error != -EBUSY))
-		return VM_FAULT_SIGBUS | major;
-	return VM_FAULT_NOPAGE | major;
-}
-EXPORT_SYMBOL_GPL(dax_fault);
-
-#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
-/*
- * The 'colour' (ie low bits) within a PMD of a page offset.  This comes up
- * more often than one might expect in the below function.
- */
-#define PG_PMD_COLOUR	((PMD_SIZE >> PAGE_SHIFT) - 1)
-
-static void __dax_dbg(struct buffer_head *bh, unsigned long address,
-		const char *reason, const char *fn)
-{
-	if (bh) {
-		char bname[BDEVNAME_SIZE];
-		bdevname(bh->b_bdev, bname);
-		pr_debug("%s: %s addr: %lx dev %s state %lx start %lld "
-			"length %zd fallback: %s\n", fn, current->comm,
-			address, bname, bh->b_state, (u64)bh->b_blocknr,
-			bh->b_size, reason);
-	} else {
-		pr_debug("%s: %s addr: %lx fallback: %s\n", fn,
-			current->comm, address, reason);
-	}
-}
-
-#define dax_pmd_dbg(bh, address, reason)	__dax_dbg(bh, address, reason, "dax_pmd")
-
-/**
- * dax_pmd_fault - handle a PMD fault on a DAX file
- * @vma: The virtual memory area where the fault occurred
- * @vmf: The description of the fault
- * @get_block: The filesystem method used to translate file offsets to blocks
- *
- * When a page fault occurs, filesystems may call this helper in their
- * pmd_fault handler for DAX files.
- */
-int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
-		pmd_t *pmd, unsigned int flags, get_block_t get_block)
-{
-	struct file *file = vma->vm_file;
-	struct address_space *mapping = file->f_mapping;
-	struct inode *inode = mapping->host;
-	struct buffer_head bh;
-	unsigned blkbits = inode->i_blkbits;
-	unsigned long pmd_addr = address & PMD_MASK;
-	bool write = flags & FAULT_FLAG_WRITE;
-	struct block_device *bdev;
-	pgoff_t size, pgoff;
-	sector_t block;
-	int result = 0;
-	bool alloc = false;
-
-	/* dax pmd mappings require pfn_t_devmap() */
-	if (!IS_ENABLED(CONFIG_FS_DAX_PMD))
-		return VM_FAULT_FALLBACK;
-
-	/* Fall back to PTEs if we're going to COW */
-	if (write && !(vma->vm_flags & VM_SHARED)) {
-		split_huge_pmd(vma, pmd, address);
-		dax_pmd_dbg(NULL, address, "cow write");
-		return VM_FAULT_FALLBACK;
-	}
-	/* If the PMD would extend outside the VMA */
-	if (pmd_addr < vma->vm_start) {
-		dax_pmd_dbg(NULL, address, "vma start unaligned");
-		return VM_FAULT_FALLBACK;
-	}
-	if ((pmd_addr + PMD_SIZE) > vma->vm_end) {
-		dax_pmd_dbg(NULL, address, "vma end unaligned");
-		return VM_FAULT_FALLBACK;
-	}
-
-	pgoff = linear_page_index(vma, pmd_addr);
-	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	if (pgoff >= size)
-		return VM_FAULT_SIGBUS;
-	/* If the PMD would cover blocks out of the file */
-	if ((pgoff | PG_PMD_COLOUR) >= size) {
-		dax_pmd_dbg(NULL, address,
-				"offset + huge page size > file size");
-		return VM_FAULT_FALLBACK;
-	}
-
-	memset(&bh, 0, sizeof(bh));
-	bh.b_bdev = inode->i_sb->s_bdev;
-	block = (sector_t)pgoff << (PAGE_SHIFT - blkbits);
-
-	bh.b_size = PMD_SIZE;
-
-	if (get_block(inode, block, &bh, 0) != 0)
-		return VM_FAULT_SIGBUS;
-
-	if (!buffer_mapped(&bh) && write) {
-		if (get_block(inode, block, &bh, 1) != 0)
-			return VM_FAULT_SIGBUS;
-		alloc = true;
-		WARN_ON_ONCE(buffer_unwritten(&bh) || buffer_new(&bh));
-	}
-
-	bdev = bh.b_bdev;
-
-	/*
-	 * If the filesystem isn't willing to tell us the length of a hole,
-	 * just fall back to PTEs.  Calling get_block 512 times in a loop
-	 * would be silly.
-	 */
-	if (!buffer_size_valid(&bh) || bh.b_size < PMD_SIZE) {
-		dax_pmd_dbg(&bh, address, "allocated block too small");
-		return VM_FAULT_FALLBACK;
-	}
-
-	/*
-	 * If we allocated new storage, make sure no process has any
-	 * zero pages covering this hole
-	 */
-	if (alloc) {
-		loff_t lstart = pgoff << PAGE_SHIFT;
-		loff_t lend = lstart + PMD_SIZE - 1; /* inclusive */
-
-		truncate_pagecache_range(inode, lstart, lend);
-	}
-
-	if (!write && !buffer_mapped(&bh)) {
-		spinlock_t *ptl;
-		pmd_t entry;
-		struct page *zero_page = mm_get_huge_zero_page(vma->vm_mm);
-
-		if (unlikely(!zero_page)) {
-			dax_pmd_dbg(&bh, address, "no zero page");
-			goto fallback;
-		}
-
-		ptl = pmd_lock(vma->vm_mm, pmd);
-		if (!pmd_none(*pmd)) {
-			spin_unlock(ptl);
-			dax_pmd_dbg(&bh, address, "pmd already present");
-			goto fallback;
-		}
-
-		dev_dbg(part_to_dev(bdev->bd_part),
-				"%s: %s addr: %lx pfn: <zero> sect: %llx\n",
-				__func__, current->comm, address,
-				(unsigned long long) to_sector(&bh, inode));
-
-		entry = mk_pmd(zero_page, vma->vm_page_prot);
-		entry = pmd_mkhuge(entry);
-		set_pmd_at(vma->vm_mm, pmd_addr, pmd, entry);
-		result = VM_FAULT_NOPAGE;
-		spin_unlock(ptl);
-	} else {
-		struct blk_dax_ctl dax = {
-			.sector = to_sector(&bh, inode),
-			.size = PMD_SIZE,
-		};
-		long length = dax_map_atomic(bdev, &dax);
-
-		if (length < 0) {
-			dax_pmd_dbg(&bh, address, "dax-error fallback");
-			goto fallback;
-		}
-		if (length < PMD_SIZE) {
-			dax_pmd_dbg(&bh, address, "dax-length too small");
-			dax_unmap_atomic(bdev, &dax);
-			goto fallback;
-		}
-		if (pfn_t_to_pfn(dax.pfn) & PG_PMD_COLOUR) {
-			dax_pmd_dbg(&bh, address, "pfn unaligned");
-			dax_unmap_atomic(bdev, &dax);
-			goto fallback;
-		}
-
-		if (!pfn_t_devmap(dax.pfn)) {
-			dax_unmap_atomic(bdev, &dax);
-			dax_pmd_dbg(&bh, address, "pfn not in memmap");
-			goto fallback;
-		}
-		dax_unmap_atomic(bdev, &dax);
-
-		/*
-		 * For PTE faults we insert a radix tree entry for reads, and
-		 * leave it clean.  Then on the first write we dirty the radix
-		 * tree entry via the dax_pfn_mkwrite() path.  This sequence
-		 * allows the dax_pfn_mkwrite() call to be simpler and avoid a
-		 * call into get_block() to translate the pgoff to a sector in
-		 * order to be able to create a new radix tree entry.
-		 *
-		 * The PMD path doesn't have an equivalent to
-		 * dax_pfn_mkwrite(), though, so for a read followed by a
-		 * write we traverse all the way through dax_pmd_fault()
-		 * twice.  This means we can just skip inserting a radix tree
-		 * entry completely on the initial read and just wait until
-		 * the write to insert a dirty entry.
-		 */
-		if (write) {
-			/*
-			 * We should insert radix-tree entry and dirty it here.
-			 * For now this is broken...
-			 */
-		}
-
-		dev_dbg(part_to_dev(bdev->bd_part),
-				"%s: %s addr: %lx pfn: %lx sect: %llx\n",
-				__func__, current->comm, address,
-				pfn_t_to_pfn(dax.pfn),
-				(unsigned long long) dax.sector);
-		result |= vmf_insert_pfn_pmd(vma, address, pmd,
-				dax.pfn, write);
-	}
-
- out:
-	return result;
-
- fallback:
-	count_vm_event(THP_FAULT_FALLBACK);
-	result = VM_FAULT_FALLBACK;
-	goto out;
-}
-EXPORT_SYMBOL_GPL(dax_pmd_fault);
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 /**
  * dax_pfn_mkwrite - handle first write to DAX page
···
 }
 EXPORT_SYMBOL_GPL(__dax_zero_page_range);
 
-/**
- * dax_zero_page_range - zero a range within a page of a DAX file
- * @inode: The file being truncated
- * @from: The file offset that is being truncated to
- * @length: The number of bytes to zero
- * @get_block: The filesystem method used to translate file offsets to blocks
- *
- * This function can be called by a filesystem when it is zeroing part of a
- * page in a DAX file.  This is intended for hole-punch operations.  If
- * you are truncating a file, the helper function dax_truncate_page() may be
- * more convenient.
- */
-int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length,
-							get_block_t get_block)
-{
-	struct buffer_head bh;
-	pgoff_t index = from >> PAGE_SHIFT;
-	unsigned offset = from & (PAGE_SIZE-1);
-	int err;
-
-	/* Block boundary? Nothing to do */
-	if (!length)
-		return 0;
-	BUG_ON((offset + length) > PAGE_SIZE);
-
-	memset(&bh, 0, sizeof(bh));
-	bh.b_bdev = inode->i_sb->s_bdev;
-	bh.b_size = PAGE_SIZE;
-	err = get_block(inode, index, &bh, 0);
-	if (err < 0 || !buffer_written(&bh))
-		return err;
-
-	return __dax_zero_page_range(bh.b_bdev, to_sector(&bh, inode),
-			offset, length);
-}
-EXPORT_SYMBOL_GPL(dax_zero_page_range);
-
-/**
- * dax_truncate_page - handle a partial page being truncated in a DAX file
- * @inode: The file being truncated
- * @from: The file offset that is being truncated to
- * @get_block: The filesystem method used to translate file offsets to blocks
- *
- * Similar to block_truncate_page(), this function can be called by a
- * filesystem when it is truncating a DAX file to handle the partial page.
- */
-int dax_truncate_page(struct inode *inode, loff_t from, get_block_t get_block)
-{
-	unsigned length = PAGE_ALIGN(from) - from;
-	return dax_zero_page_range(inode, from, length, get_block);
-}
-EXPORT_SYMBOL_GPL(dax_truncate_page);
-
 #ifdef CONFIG_FS_IOMAP
+static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
+{
+	return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
+}
+
 static loff_t
-iomap_dax_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
+dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 		struct iomap *iomap)
 {
 	struct iov_iter *iter = data;
···
 		struct blk_dax_ctl dax = { 0 };
 		ssize_t map_len;
 
-		dax.sector = iomap->blkno +
-			(((pos & PAGE_MASK) - iomap->offset) >> 9);
+		dax.sector = dax_iomap_sector(iomap, pos);
 		dax.size = (length + offset + PAGE_SIZE - 1) & PAGE_MASK;
 		map_len = dax_map_atomic(iomap->bdev, &dax);
 		if (map_len < 0) {
···
 }
 
 /**
- * iomap_dax_rw - Perform I/O to a DAX file
+ * dax_iomap_rw - Perform I/O to a DAX file
  * @iocb:	The control block for this I/O
  * @iter:	The addresses to do I/O from or to
  * @ops:	iomap ops passed from the file system
···
  * and evicting any page cache pages in the region under I/O.
  */
 ssize_t
-iomap_dax_rw(struct kiocb *iocb, struct iov_iter *iter,
+dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
 		struct iomap_ops *ops)
 {
 	struct address_space *mapping = iocb->ki_filp->f_mapping;
···
 
 	while (iov_iter_count(iter)) {
 		ret = iomap_apply(inode, pos, iov_iter_count(iter), flags, ops,
-				iter, iomap_dax_actor);
+				iter, dax_iomap_actor);
 		if (ret <= 0)
 			break;
 		pos += ret;
···
 	iocb->ki_pos += done;
 	return done ? done : ret;
 }
-EXPORT_SYMBOL_GPL(iomap_dax_rw);
+EXPORT_SYMBOL_GPL(dax_iomap_rw);
 
 /**
- * iomap_dax_fault - handle a page fault on a DAX file
+ * dax_iomap_fault - handle a page fault on a DAX file
  * @vma: The virtual memory area where the fault occurred
  * @vmf: The description of the fault
  * @ops: iomap ops passed from the file system
···
  * or mkwrite handler for DAX files. Assumes the caller has done all the
  * necessary locking for the page fault to proceed successfully.
  */
-int iomap_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
+int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 			struct iomap_ops *ops)
 {
 	struct address_space *mapping = vma->vm_file->f_mapping;
···
 	loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
 	sector_t sector;
 	struct iomap iomap = { 0 };
-	unsigned flags = 0;
+	unsigned flags = IOMAP_FAULT;
 	int error, major = 0;
+	int locked_status = 0;
 	void *entry;
 
 	/*
···
 	if (pos >= i_size_read(inode))
 		return VM_FAULT_SIGBUS;
 
-	entry = grab_mapping_entry(mapping, vmf->pgoff);
+	entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
 	if (IS_ERR(entry)) {
 		error = PTR_ERR(entry);
 		goto out;
···
 		goto unlock_entry;
 	if (WARN_ON_ONCE(iomap.offset + iomap.length < pos + PAGE_SIZE)) {
 		error = -EIO;		/* fs corruption? */
-		goto unlock_entry;
+		goto finish_iomap;
 	}
 
-	sector = iomap.blkno + (((pos & PAGE_MASK) - iomap.offset) >> 9);
+	sector = dax_iomap_sector(&iomap, pos);
 
 	if (vmf->cow_page) {
 		switch (iomap.type) {
···
 		}
 
 		if (error)
-			goto unlock_entry;
+			goto finish_iomap;
 		if (!radix_tree_exceptional_entry(entry)) {
 			vmf->page = entry;
-			return VM_FAULT_LOCKED;
+			locked_status = VM_FAULT_LOCKED;
+		} else {
+			vmf->entry = entry;
+			locked_status = VM_FAULT_DAX_LOCKED;
 		}
-		vmf->entry = entry;
-		return VM_FAULT_DAX_LOCKED;
+		goto finish_iomap;
 	}
 
 	switch (iomap.type) {
···
 		break;
 	case IOMAP_UNWRITTEN:
 	case IOMAP_HOLE:
-		if (!(vmf->flags & FAULT_FLAG_WRITE))
-			return dax_load_hole(mapping, entry, vmf);
+		if (!(vmf->flags & FAULT_FLAG_WRITE)) {
+			locked_status = dax_load_hole(mapping, entry, vmf);
+			break;
+		}
 		/*FALLTHRU*/
 	default:
 		WARN_ON_ONCE(1);
···
 		break;
 	}
 
+ finish_iomap:
+	if (ops->iomap_end) {
+		if (error) {
+			/* keep previous error */
+			ops->iomap_end(inode, pos, PAGE_SIZE, 0, flags,
+					&iomap);
+		} else {
+			error = ops->iomap_end(inode, pos, PAGE_SIZE,
+					PAGE_SIZE, flags, &iomap);
+		}
+	}
  unlock_entry:
-	put_locked_mapping_entry(mapping, vmf->pgoff, entry);
+	if (!locked_status || error)
+		put_locked_mapping_entry(mapping, vmf->pgoff, entry);
  out:
 	if (error == -ENOMEM)
 		return VM_FAULT_OOM | major;
 	/* -EBUSY is fine, somebody else faulted on the same PTE */
 	if (error < 0 && error != -EBUSY)
 		return VM_FAULT_SIGBUS | major;
+	if (locked_status) {
+		WARN_ON_ONCE(error); /* -EBUSY from ops->iomap_end? */
+		return locked_status;
+	}
 	return VM_FAULT_NOPAGE | major;
 }
-EXPORT_SYMBOL_GPL(iomap_dax_fault);
+EXPORT_SYMBOL_GPL(dax_iomap_fault);
+
+#ifdef CONFIG_FS_DAX_PMD
+/*
+ * The 'colour' (ie low bits) within a PMD of a page offset.  This comes up
+ * more often than one might expect in the below functions.
+ */
+#define PG_PMD_COLOUR	((PMD_SIZE >> PAGE_SHIFT) - 1)
+
+static int dax_pmd_insert_mapping(struct vm_area_struct *vma, pmd_t *pmd,
+		struct vm_fault *vmf, unsigned long address,
+		struct iomap *iomap, loff_t pos, bool write, void **entryp)
+{
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	struct block_device *bdev = iomap->bdev;
+	struct blk_dax_ctl dax = {
+		.sector = dax_iomap_sector(iomap, pos),
+		.size = PMD_SIZE,
+	};
+	long length = dax_map_atomic(bdev, &dax);
+	void *ret;
+
+	if (length < 0) /* dax_map_atomic() failed */
+		return VM_FAULT_FALLBACK;
+	if (length < PMD_SIZE)
+		goto unmap_fallback;
+	if (pfn_t_to_pfn(dax.pfn) & PG_PMD_COLOUR)
+		goto unmap_fallback;
+	if (!pfn_t_devmap(dax.pfn))
+		goto unmap_fallback;
+
+	dax_unmap_atomic(bdev, &dax);
+
+	ret = dax_insert_mapping_entry(mapping, vmf, *entryp, dax.sector,
+			RADIX_DAX_PMD);
+	if (IS_ERR(ret))
+		return VM_FAULT_FALLBACK;
+	*entryp = ret;
+
+	return vmf_insert_pfn_pmd(vma, address, pmd, dax.pfn, write);
+
+ unmap_fallback:
+	dax_unmap_atomic(bdev, &dax);
+	return VM_FAULT_FALLBACK;
+}
+
+static int dax_pmd_load_hole(struct vm_area_struct *vma, pmd_t *pmd,
+		struct vm_fault *vmf, unsigned long address,
+		struct iomap *iomap, void **entryp)
+{
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	unsigned long pmd_addr = address & PMD_MASK;
+	struct page *zero_page;
+	spinlock_t *ptl;
+	pmd_t pmd_entry;
+	void *ret;
+
+	zero_page = mm_get_huge_zero_page(vma->vm_mm);
+
+	if (unlikely(!zero_page))
+		return VM_FAULT_FALLBACK;
+
+	ret = dax_insert_mapping_entry(mapping, vmf, *entryp, 0,
+			RADIX_DAX_PMD | RADIX_DAX_HZP);
+	if (IS_ERR(ret))
+		return VM_FAULT_FALLBACK;
+	*entryp = ret;
+
+	ptl = pmd_lock(vma->vm_mm, pmd);
+	if (!pmd_none(*pmd)) {
+		spin_unlock(ptl);
+		return VM_FAULT_FALLBACK;
+	}
+
+	pmd_entry = mk_pmd(zero_page, vma->vm_page_prot);
+	pmd_entry = pmd_mkhuge(pmd_entry);
+	set_pmd_at(vma->vm_mm, pmd_addr, pmd, pmd_entry);
+	spin_unlock(ptl);
+	return VM_FAULT_NOPAGE;
+}
+
+int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address,
+		pmd_t *pmd, unsigned int flags, struct iomap_ops *ops)
+{
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	unsigned long pmd_addr = address & PMD_MASK;
+	bool write = flags & FAULT_FLAG_WRITE;
+	unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT;
+	struct inode *inode = mapping->host;
+	int result = VM_FAULT_FALLBACK;
+	struct iomap iomap = { 0 };
+	pgoff_t max_pgoff, pgoff;
+	struct vm_fault vmf;
+	void *entry;
+	loff_t pos;
+	int error;
+
+	/* Fall back to PTEs if we're going to COW */
+	if (write && !(vma->vm_flags & VM_SHARED))
+		goto fallback;
+
+	/* If the PMD would extend outside the VMA */
+	if (pmd_addr < vma->vm_start)
+		goto fallback;
+	if ((pmd_addr + PMD_SIZE) > vma->vm_end)
+		goto fallback;
+
+	/*
+	 * Check whether offset isn't beyond end of file now. Caller is
+	 * supposed to hold locks serializing us with truncate / punch hole so
+	 * this is a reliable test.
+	 */
+	pgoff = linear_page_index(vma, pmd_addr);
+	max_pgoff = (i_size_read(inode) - 1) >> PAGE_SHIFT;
+
+	if (pgoff > max_pgoff)
+		return VM_FAULT_SIGBUS;
+
+	/* If the PMD would extend beyond the file size */
+	if ((pgoff | PG_PMD_COLOUR) > max_pgoff)
+		goto fallback;
+
+	/*
+	 * grab_mapping_entry() will make sure we get a 2M empty entry, a DAX
+	 * PMD or a HZP entry.  If it can't (because a 4k page is already in
+	 * the tree, for instance), it will return -EEXIST and we just fall
+	 * back to 4k entries.
+	 */
+	entry = grab_mapping_entry(mapping, pgoff, RADIX_DAX_PMD);
+	if (IS_ERR(entry))
+		goto fallback;
+
+	/*
+	 * Note that we don't use iomap_apply here.  We aren't doing I/O, only
+	 * setting up a mapping, so really we're using iomap_begin() as a way
+	 * to look up our filesystem block.
+	 */
+	pos = (loff_t)pgoff << PAGE_SHIFT;
+	error = ops->iomap_begin(inode, pos, PMD_SIZE, iomap_flags, &iomap);
+	if (error)
+		goto unlock_entry;
+	if (iomap.offset + iomap.length < pos + PMD_SIZE)
+		goto finish_iomap;
+
+	vmf.pgoff = pgoff;
+	vmf.flags = flags;
+	vmf.gfp_mask = mapping_gfp_mask(mapping) | __GFP_IO;
+
+	switch (iomap.type) {
+	case IOMAP_MAPPED:
+		result = dax_pmd_insert_mapping(vma, pmd, &vmf, address,
+				&iomap, pos, write, &entry);
+		break;
+	case IOMAP_UNWRITTEN:
+	case IOMAP_HOLE:
+		if (WARN_ON_ONCE(write))
+			goto finish_iomap;
+		result = dax_pmd_load_hole(vma, pmd, &vmf, address, &iomap,
+				&entry);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+
+ finish_iomap:
+	if (ops->iomap_end) {
+		if (result == VM_FAULT_FALLBACK) {
+			ops->iomap_end(inode, pos, PMD_SIZE, 0, iomap_flags,
+					&iomap);
+		} else {
+			error = ops->iomap_end(inode, pos, PMD_SIZE, PMD_SIZE,
+					iomap_flags, &iomap);
+			if (error)
+				result = VM_FAULT_FALLBACK;
+		}
+	}
+ unlock_entry:
+	put_locked_mapping_entry(mapping, pgoff, entry);
+ fallback:
+	if (result == VM_FAULT_FALLBACK) {
+		split_huge_pmd(vma, pmd, address);
+		count_vm_event(THP_FAULT_FALLBACK);
+	}
+	return result;
+}
+EXPORT_SYMBOL_GPL(dax_iomap_pmd_fault);
+#endif /* CONFIG_FS_DAX_PMD */
 #endif /* CONFIG_FS_IOMAP */

fs/ext2/file.c

···
 		return 0; /* skip atime */
 
 	inode_lock_shared(inode);
-	ret = iomap_dax_rw(iocb, to, &ext2_iomap_ops);
+	ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);
 	inode_unlock_shared(inode);
 
 	file_accessed(iocb->ki_filp);
···
 	if (ret)
 		goto out_unlock;
 
-	ret = iomap_dax_rw(iocb, from, &ext2_iomap_ops);
+	ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops);
 	if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
 		i_size_write(inode, iocb->ki_pos);
 		mark_inode_dirty(inode);
···
 	}
 	down_read(&ei->dax_sem);
 
-	ret = iomap_dax_fault(vma, vmf, &ext2_iomap_ops);
+	ret = dax_iomap_fault(vma, vmf, &ext2_iomap_ops);
 
 	up_read(&ei->dax_sem);
 	if (vmf->flags & FAULT_FLAG_WRITE)
-		sb_end_pagefault(inode->i_sb);
-	return ret;
-}
-
-static int ext2_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
-						pmd_t *pmd, unsigned int flags)
-{
-	struct inode *inode = file_inode(vma->vm_file);
-	struct ext2_inode_info *ei = EXT2_I(inode);
-	int ret;
-
-	if (flags & FAULT_FLAG_WRITE) {
-		sb_start_pagefault(inode->i_sb);
-		file_update_time(vma->vm_file);
-	}
-	down_read(&ei->dax_sem);
-
-	ret = dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block);
-
-	up_read(&ei->dax_sem);
-	if (flags & FAULT_FLAG_WRITE)
 		sb_end_pagefault(inode->i_sb);
 	return ret;
 }
···
 
 static const struct vm_operations_struct ext2_dax_vm_ops = {
 	.fault		= ext2_dax_fault,
-	.pmd_fault	= ext2_dax_pmd_fault,
+	/*
+	 * .pmd_fault is not supported for DAX because allocation in ext2
+	 * cannot be reliably aligned to huge page sizes and so pmd faults
+	 * will always fail and fail back to regular faults.
+	 */
 	.page_mkwrite	= ext2_dax_fault,
 	.pfn_mkwrite	= ext2_dax_pfn_mkwrite,
 };
···
 
 	file_accessed(file);
 	vma->vm_ops = &ext2_dax_vm_ops;
-	vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
+	vma->vm_flags |= VM_MIXEDMAP;
 	return 0;
 }
 #else

fs/ext2/inode.c

···
 	.iomap_begin		= ext2_iomap_begin,
 	.iomap_end		= ext2_iomap_end,
 };
+#else
+/* Define empty ops for !CONFIG_FS_DAX case to avoid ugly ifdefs */
+struct iomap_ops ext2_iomap_ops;
 #endif /* CONFIG_FS_DAX */
 
 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
···
 
 	inode_dio_wait(inode);
 
-	if (IS_DAX(inode))
-		error = dax_truncate_page(inode, newsize, ext2_get_block);
-	else if (test_opt(inode->i_sb, NOBH))
+	if (IS_DAX(inode)) {
+		error = iomap_zero_range(inode, newsize,
+					 PAGE_ALIGN(newsize) - newsize, NULL,
+					 &ext2_iomap_ops);
+	} else if (test_opt(inode->i_sb, NOBH))
 		error = nobh_truncate_page(inode->i_mapping,
 				newsize, ext2_get_block);
 	else

fs/ext4/Kconfig

···
 	select CRC16
 	select CRYPTO
 	select CRYPTO_CRC32C
+	select FS_IOMAP if FS_DAX
 	help
 	  This is the next generation of the ext3 filesystem.
 

fs/ext4/acl.c

···
 			error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
 			if (error)
 				return error;
-			inode->i_ctime = ext4_current_time(inode);
+			inode->i_ctime = current_time(inode);
 			ext4_mark_inode_dirty(handle, inode);
 		}
 		break;

fs/ext4/ext4.h

···
 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
 
 #define EXT4_FL_USER_VISIBLE		0x304BDFFF /* User visible flags */
-#define EXT4_FL_USER_MODIFIABLE		0x204380FF /* User modifiable flags */
+#define EXT4_FL_USER_MODIFIABLE		0x204BC0FF /* User modifiable flags */
 
+/* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */
 #define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
 					 EXT4_IMMUTABLE_FL | \
 					 EXT4_APPEND_FL | \
···
 	return container_of(inode, struct ext4_inode_info, vfs_inode);
 }
 
-static inline struct timespec ext4_current_time(struct inode *inode)
-{
-	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
-		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
-}
-
 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
 {
 	return ino == EXT4_ROOT_INO ||
···
 					      struct ext4_group_desc *gdp);
 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
 
-static inline int ext4_sb_has_crypto(struct super_block *sb)
-{
-	return ext4_has_feature_encrypt(sb);
-}
-
 static inline bool ext4_encrypted_inode(struct inode *inode)
 {
 	return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
···
 #define fscrypt_pullback_bio_page	fscrypt_notsupp_pullback_bio_page
 #define fscrypt_restore_control_page	fscrypt_notsupp_restore_control_page
 #define fscrypt_zeroout_range		fscrypt_notsupp_zeroout_range
-#define fscrypt_process_policy		fscrypt_notsupp_process_policy
-#define fscrypt_get_policy		fscrypt_notsupp_get_policy
+#define fscrypt_ioctl_set_policy	fscrypt_notsupp_ioctl_set_policy
+#define fscrypt_ioctl_get_policy	fscrypt_notsupp_ioctl_get_policy
 #define fscrypt_has_permitted_context	fscrypt_notsupp_has_permitted_context
 #define fscrypt_inherit_context		fscrypt_notsupp_inherit_context
 #define fscrypt_get_encryption_info	fscrypt_notsupp_get_encryption_info
···
 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
 int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
 			     struct buffer_head *bh_result, int create);
-int ext4_dax_get_block(struct inode *inode, sector_t iblock,
-		       struct buffer_head *bh_result, int create);
 int ext4_get_block(struct inode *inode, sector_t iblock,
 		   struct buffer_head *bh_result, int create);
 int ext4_dio_get_block(struct inode *inode, sector_t iblock,
···
 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
 extern int ext4_inode_attach_jinode(struct inode *inode);
 extern int ext4_can_truncate(struct inode *inode);
-extern void ext4_truncate(struct inode *);
+extern int ext4_truncate(struct inode *);
 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
 extern void ext4_set_inode_flags(struct inode *);
···
 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 			       struct ext4_map_blocks *map, int flags);
-extern void ext4_ext_truncate(handle_t *, struct inode *);
+extern int ext4_ext_truncate(handle_t *, struct inode *);
 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
 				 ext4_lblk_t end);
 extern void ext4_ext_init(struct super_block *);
···
 	}
 }
 
-static inline bool ext4_aligned_io(struct inode *inode, loff_t off, loff_t len)
-{
-	int blksize = 1 << inode->i_blkbits;
-
-	return IS_ALIGNED(off, blksize) && IS_ALIGNED(len, blksize);
-}
+extern struct iomap_ops ext4_iomap_ops;
 
 #endif	/* __KERNEL__ */
 

fs/ext4/ext4_jbd2.h

···
 		return EXT4_INODE_WRITEBACK_DATA_MODE;	/* writeback */
 	/* We do not support data journalling with delayed allocation */
 	if (!S_ISREG(inode->i_mode) ||
-	    test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
+	    test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
+	    (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
+	    !test_opt(inode->i_sb, DELALLOC))) {
+		/* We do not support data journalling for encrypted data */
+		if (S_ISREG(inode->i_mode) && ext4_encrypted_inode(inode))
+			return EXT4_INODE_ORDERED_DATA_MODE;  /* ordered */
 		return EXT4_INODE_JOURNAL_DATA_MODE;	/* journal data */
-	if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
-	    !test_opt(inode->i_sb, DELALLOC))
-		return EXT4_INODE_JOURNAL_DATA_MODE;	/* journal data */
+	}
 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 		return EXT4_INODE_ORDERED_DATA_MODE;	/* ordered */
 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 		return EXT4_INODE_WRITEBACK_DATA_MODE;	/* writeback */
-	else
-		BUG();
+	BUG();
 }
 
 static inline int ext4_should_journal_data(struct inode *inode)

fs/ext4/extents.c

···
 	return err ? err : allocated;
 }
 
-void ext4_ext_truncate(handle_t *handle, struct inode *inode)
+int ext4_ext_truncate(handle_t *handle, struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
 	ext4_lblk_t last_block;
···
 
 	/* we have to know where to truncate from in crash case */
 	EXT4_I(inode)->i_disksize = inode->i_size;
-	ext4_mark_inode_dirty(handle, inode);
+	err = ext4_mark_inode_dirty(handle, inode);
+	if (err)
+		return err;
 
 	last_block = (inode->i_size + sb->s_blocksize - 1)
 			>> EXT4_BLOCK_SIZE_BITS(sb);
···
 		congestion_wait(BLK_RW_ASYNC, HZ/50);
 		goto retry;
 	}
-	if (err) {
-		ext4_std_error(inode->i_sb, err);
-		return;
-	}
-	err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
-	ext4_std_error(inode->i_sb, err);
+	if (err)
+		return err;
+	return ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
 }
 
 static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
···
 		/*
 		 * Recalculate credits when extent tree depth changes.
 		 */
-		if (depth >= 0 && depth != ext_depth(inode)) {
+		if (depth != ext_depth(inode)) {
 			credits = ext4_chunk_trans_blocks(inode, len);
 			depth = ext_depth(inode);
 		}
···
 		map.m_lblk += ret;
 		map.m_len = len = len - ret;
 		epos = (loff_t)map.m_lblk << inode->i_blkbits;
-		inode->i_ctime = ext4_current_time(inode);
+		inode->i_ctime = current_time(inode);
 		if (new_size) {
 			if (epos > new_size)
 				epos = new_size;
···
 		}
 		/* Now release the pages and zero block aligned part of pages */
 		truncate_pagecache_range(inode, start, end - 1);
-		inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+		inode->i_mtime = inode->i_ctime = current_time(inode);
 
 		ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
 					     flags, mode);
···
 		goto out_dio;
 	}
 
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	if (new_size) {
 		ext4_update_inode_size(inode, new_size);
 	} else {
···
 	up_write(&EXT4_I(inode)->i_data_sem);
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 
 out_stop:
···
 	/* Expand file to avoid data loss if there is error while shifting */
 	inode->i_size += len;
 	EXT4_I(inode)->i_disksize += len;
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ret = ext4_mark_inode_dirty(handle, inode);
 	if (ret)
 		goto out_stop;

fs/ext4/file.c

···
 #include "xattr.h"
 #include "acl.h"
 
+#ifdef CONFIG_FS_DAX
+static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	ssize_t ret;
+
+	inode_lock_shared(inode);
+	/*
+	 * Recheck under inode lock - at this point we are sure it cannot
+	 * change anymore
+	 */
+	if (!IS_DAX(inode)) {
+		inode_unlock_shared(inode);
+		/* Fallback to buffered IO in case we cannot support DAX */
+		return generic_file_read_iter(iocb, to);
+	}
+	ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops);
+	inode_unlock_shared(inode);
+
+	file_accessed(iocb->ki_filp);
+	return ret;
+}
+#endif
+
+static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	if (!iov_iter_count(to))
+		return 0; /* skip atime */
+
+#ifdef CONFIG_FS_DAX
+	if (IS_DAX(file_inode(iocb->ki_filp)))
+		return ext4_dax_read_iter(iocb, to);
+#endif
+	return generic_file_read_iter(iocb, to);
+}
+
 /*
  * Called when an inode is released. Note that this is different
  * from ext4_file_open: open gets called at every open, but release
···
 	return 0;
 }
 
+/* Is IO overwriting allocated and initialized blocks? */
+static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len)
+{
+	struct ext4_map_blocks map;
+	unsigned int blkbits = inode->i_blkbits;
+	int err, blklen;
+
+	if (pos + len > i_size_read(inode))
+		return false;
+
+	map.m_lblk = pos >> blkbits;
+	map.m_len = EXT4_MAX_BLOCKS(len, pos, blkbits);
+	blklen = map.m_len;
+
+	err = ext4_map_blocks(NULL, inode, &map, 0);
+	/*
+	 * 'err==len' means that all of the blocks have been preallocated,
+	 * regardless of whether they have been initialized or not. To exclude
+	 * unwritten extents, we need to check m_flags.
+	 */
+	return err == blklen && (map.m_flags & EXT4_MAP_MAPPED);
+}
+
+static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	ssize_t ret;
+
+	ret = generic_write_checks(iocb, from);
+	if (ret <= 0)
+		return ret;
+	/*
+	 * If we have encountered a bitmap-format file, the size limit
+	 * is smaller than s_maxbytes, which is for extent-mapped files.
+	 */
+	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+		if (iocb->ki_pos >= sbi->s_bitmap_maxbytes)
+			return -EFBIG;
+		iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
+	}
+	return iov_iter_count(from);
+}
+
+#ifdef CONFIG_FS_DAX
+static ssize_t
+ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	ssize_t ret;
+	bool overwrite = false;
+
+	inode_lock(inode);
+	ret = ext4_write_checks(iocb, from);
+	if (ret <= 0)
+		goto out;
+	ret = file_remove_privs(iocb->ki_filp);
+	if (ret)
+		goto out;
+	ret = file_update_time(iocb->ki_filp);
+	if (ret)
+		goto out;
+
+	if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) {
+		overwrite = true;
+		downgrade_write(&inode->i_rwsem);
+	}
+	ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
+out:
+	if (!overwrite)
+		inode_unlock(inode);
+	else
+		inode_unlock_shared(inode);
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
+	return ret;
+}
+#endif
+
 static ssize_t
 ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
···
 	int overwrite = 0;
 	ssize_t ret;
 
+#ifdef CONFIG_FS_DAX
+	if (IS_DAX(inode))
+		return ext4_dax_write_iter(iocb, from);
+#endif
+
 	inode_lock(inode);
-	ret = generic_write_checks(iocb, from);
+	ret = ext4_write_checks(iocb, from);
 	if (ret <= 0)
 		goto out;
 
···
 		ext4_unwritten_wait(inode);
 	}
 
-	/*
-	 * If we have encountered a bitmap-format file, the size limit
-	 * is smaller than s_maxbytes, which is for extent-mapped files.
-	 */
-	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
-		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-
-		if (iocb->ki_pos >= sbi->s_bitmap_maxbytes) {
-			ret = -EFBIG;
-			goto out;
-		}
-		iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
-	}
-
 	iocb->private = &overwrite;
-	if (o_direct) {
-		size_t length = iov_iter_count(from);
-		loff_t pos = iocb->ki_pos;
-
-		/* check whether we do a DIO overwrite or not */
-		if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
-		    pos + length <= i_size_read(inode)) {
-			struct ext4_map_blocks map;
-			unsigned int blkbits = inode->i_blkbits;
-			int err, len;
-
-			map.m_lblk = pos >> blkbits;
-			map.m_len = EXT4_MAX_BLOCKS(length, pos, blkbits);
-			len = map.m_len;
-
-			err = ext4_map_blocks(NULL, inode, &map, 0);
-			/*
-			 * 'err==len' means that all of blocks has
-			 * been preallocated no matter they are
-			 * initialized or not.  For excluding
-			 * unwritten extents, we need to check
-			 * m_flags.  There are two conditions that
-			 * indicate for initialized extents.  1) If we
-			 * hit extent cache, EXT4_MAP_MAPPED flag is
-			 * returned; 2) If we do a real lookup,
-			 * non-flags are returned.  So we should check
-			 * these two conditions.
-			 */
-			if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
-				overwrite = 1;
-		}
-	}
+	/* Check whether we do a DIO overwrite or not */
+	if (o_direct && ext4_should_dioread_nolock(inode) && !unaligned_aio &&
+	    ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from)))
+		overwrite = 1;
 
 	ret = __generic_file_write_iter(iocb, from);
 	inode_unlock(inode);
···
 	if (IS_ERR(handle))
 		result = VM_FAULT_SIGBUS;
 	else
-		result = dax_fault(vma, vmf, ext4_dax_get_block);
+		result = dax_iomap_fault(vma, vmf, &ext4_iomap_ops);
 
 	if (write) {
 		if (!IS_ERR(handle))
···
 
 	if (IS_ERR(handle))
 		result = VM_FAULT_SIGBUS;
-	else
-		result = dax_pmd_fault(vma, addr, pmd, flags,
-					 ext4_dax_get_block);
+	else {
+		result = dax_iomap_pmd_fault(vma, addr, pmd, flags,
+					     &ext4_iomap_ops);
+	}
 
 	if (write) {
 		if (!IS_ERR(handle))
···
 
 const struct file_operations ext4_file_operations = {
 	.llseek		= ext4_llseek,
-	.read_iter	= generic_file_read_iter,
+	.read_iter	= ext4_file_read_iter,
 	.write_iter	= ext4_file_write_iter,
 	.unlocked_ioctl = ext4_ioctl,
 #ifdef CONFIG_COMPAT

fs/ext4/ialloc.c

···
 	/* This is the optimal IO size (for stat), not the fs block size */
 	inode->i_blocks = 0;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
-						       ext4_current_time(inode);
+						       current_time(inode);
 
 	memset(ei->i_data, 0, sizeof(ei->i_data));
 	ei->i_dir_start_lookup = 0;
···
 	}
 
 	if (encrypt) {
-		/* give pointer to avoid set_context with journal ops. */
-		err = fscrypt_inherit_context(dir, inode, &encrypt, true);
+		err = fscrypt_inherit_context(dir, inode, handle, true);
 		if (err)
 			goto fail_free_drop;
 	}

fs/ext4/inline.c

···
 	EXT4_I(inode)->i_inline_size = len + EXT4_MIN_INLINE_DATA_SIZE;
 	ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
 	ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA);
+	/*
+	 * Propagate changes to inode->i_flags as well - e.g. S_DAX may
+	 * get cleared
+	 */
+	ext4_set_inode_flags(inode);
 	get_bh(is.iloc.bh);
 	error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
 
···
 
 	len -= EXT4_MIN_INLINE_DATA_SIZE;
 	value = kzalloc(len, GFP_NOFS);
-	if (!value)
+	if (!value) {
+		error = -ENOMEM;
 		goto out;
+	}
 
 	error = ext4_xattr_ibody_get(inode, i.name_index, i.name,
 				     value, len);
···
 		}
 	}
 	ext4_clear_inode_flag(inode, EXT4_INODE_INLINE_DATA);
+	/*
+	 * Propagate changes to inode->i_flags as well - e.g. S_DAX may
+	 * get set.
+	 */
+	ext4_set_inode_flags(inode);
 
 	get_bh(is.iloc.bh);
 	error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
···
 	 * happen is that the times are slightly out of date
 	 * and/or different from the directory change time.
 	 */
-	dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
+	dir->i_mtime = dir->i_ctime = current_time(dir);
 	ext4_update_dx_flag(dir);
 	dir->i_version++;
 	ext4_mark_inode_dirty(handle, dir);
···
 	if (inode->i_nlink)
 		ext4_orphan_del(handle, inode);
 
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);

fs/ext4/inode.c

···
 #include <linux/printk.h>
 #include <linux/slab.h>
 #include <linux/bitops.h>
+#include <linux/iomap.h>
 
 #include "ext4_jbd2.h"
 #include "xattr.h"
···
 			csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum,
 					   csum_size);
 			offset += csum_size;
-			csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset,
-					   EXT4_INODE_SIZE(inode->i_sb) -
-					   offset);
 		}
+		csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset,
+				   EXT4_INODE_SIZE(inode->i_sb) - offset);
 	}
 
 	return csum;
···
 			     "couldn't mark inode dirty (err %d)", err);
 		goto stop_handle;
 	}
-	if (inode->i_blocks)
-		ext4_truncate(inode);
+	if (inode->i_blocks) {
+		err = ext4_truncate(inode);
+		if (err) {
+			ext4_error(inode->i_sb,
+				   "couldn't truncate inode %lu (err %d)",
+				   inode->i_ino, err);
+			goto stop_handle;
+		}
+	}
 
 	/*
 	 * ext4_ext_truncate() doesn't reserve any slop when it
···
 		ext4_update_bh_state(bh, map.m_flags);
 		bh->b_size = inode->i_sb->s_blocksize * map.m_len;
 		ret = 0;
+	} else if (ret == 0) {
+		/* hole case, need to fill in bh->b_size */
+		bh->b_size = inode->i_sb->s_blocksize * map.m_len;
 	}
 	return ret;
 }
···
 	if (unlikely(err))
 		page_zero_new_buffers(page, from, to);
 	else if (decrypt)
-		err = fscrypt_decrypt_page(page);
+		err = fscrypt_decrypt_page(page->mapping->host, page,
+				PAGE_SIZE, 0, page->index);
 	return err;
 }
 #endif
···
 
 	index = pos >> PAGE_SHIFT;
 
-	if (ext4_nonda_switch(inode->i_sb)) {
+	if (ext4_nonda_switch(inode->i_sb) ||
+	    S_ISLNK(inode->i_mode)) {
 		*fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
 		return ext4_write_begin(file, mapping, pos,
 					len, flags, pagep, fsdata);
···
 }
 
 #ifdef CONFIG_FS_DAX
-/*
- * Get block function for DAX IO and mmap faults. It takes care of converting
- * unwritten extents to written ones and initializes new / converted blocks
- * to zeros.
- */
-int ext4_dax_get_block(struct inode *inode, sector_t iblock,
-		       struct buffer_head *bh_result, int create)
+static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+			    unsigned flags, struct iomap *iomap)
 {
+	unsigned int blkbits = inode->i_blkbits;
+	unsigned long first_block = offset >> blkbits;
+	unsigned long last_block = (offset + length - 1) >> blkbits;
+	struct ext4_map_blocks map;
 	int ret;
 
-	ext4_debug("inode %lu, create flag %d\n", inode->i_ino, create);
-	if (!create)
-		return _ext4_get_block(inode, iblock, bh_result, 0);
+	if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
+		return -ERANGE;
 
-	ret = ext4_get_block_trans(inode, iblock, bh_result,
-				   EXT4_GET_BLOCKS_PRE_IO |
-				   EXT4_GET_BLOCKS_CREATE_ZERO);
-	if (ret < 0)
-		return ret;
+	map.m_lblk = first_block;
+	map.m_len = last_block - first_block + 1;
 
-	if (buffer_unwritten(bh_result)) {
+	if (!(flags & IOMAP_WRITE)) {
+		ret = ext4_map_blocks(NULL, inode, &map, 0);
+	} else {
+		int dio_credits;
+		handle_t *handle;
+		int retries = 0;
+
+		/* Trim mapping request to maximum we can map at once for DIO */
+		if (map.m_len > DIO_MAX_BLOCKS)
+			map.m_len = DIO_MAX_BLOCKS;
+		dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
+retry:
 		/*
-		 * We are protected by i_mmap_sem or i_mutex so we know block
-		 * cannot go away from under us even though we dropped
-		 * i_data_sem. Convert extent to written and write zeros there.
+		 * Either we allocate blocks and then we don't get unwritten
+		 * extent so we have reserved enough credits, or the blocks
+		 * are already allocated and unwritten and in that case
+		 * extent conversion fits in the credits as well.
 		 */
-		ret = ext4_get_block_trans(inode, iblock, bh_result,
-					   EXT4_GET_BLOCKS_CONVERT |
-					   EXT4_GET_BLOCKS_CREATE_ZERO);
-		if (ret < 0)
+		handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
+					    dio_credits);
+		if (IS_ERR(handle))
+			return PTR_ERR(handle);
+
+		ret = ext4_map_blocks(handle, inode, &map,
+				      EXT4_GET_BLOCKS_CREATE_ZERO);
+		if (ret < 0) {
+			ext4_journal_stop(handle);
+			if (ret == -ENOSPC &&
+			    ext4_should_retry_alloc(inode->i_sb, &retries))
+				goto retry;
 			return ret;
+		}
+
+		/*
+		 * If we added blocks beyond i_size, we need to make sure they
+		 * will get truncated if we crash before updating i_size in
+		 * ext4_iomap_end(). For faults we don't need to do that (and
+		 * even cannot because for orphan list operations inode_lock is
+		 * required) - if we happen to instantiate block beyond i_size,
+		 * it is because we race with truncate which has already added
+		 * the inode to the orphan list.
+		 */
+		if (!(flags & IOMAP_FAULT) && first_block + map.m_len >
+		    (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) {
+			int err;
+
+			err = ext4_orphan_add(handle, inode);
+			if (err < 0) {
+				ext4_journal_stop(handle);
+				return err;
+			}
+		}
+		ext4_journal_stop(handle);
+	}
+
+	iomap->flags = 0;
+	iomap->bdev = inode->i_sb->s_bdev;
+	iomap->offset = first_block << blkbits;
+
+	if (ret == 0) {
+		iomap->type = IOMAP_HOLE;
+		iomap->blkno = IOMAP_NULL_BLOCK;
+		iomap->length = (u64)map.m_len << blkbits;
+	} else {
+		if (map.m_flags & EXT4_MAP_MAPPED) {
+			iomap->type = IOMAP_MAPPED;
+		} else if (map.m_flags & EXT4_MAP_UNWRITTEN) {
+			iomap->type = IOMAP_UNWRITTEN;
+		} else {
+			WARN_ON_ONCE(1);
+			return -EIO;
+		}
+		iomap->blkno = (sector_t)map.m_pblk << (blkbits - 9);
+		iomap->length = (u64)map.m_len << blkbits;
+	}
+
+	if (map.m_flags & EXT4_MAP_NEW)
+		iomap->flags |= IOMAP_F_NEW;
+	return 0;
+}
+
+static int ext4_iomap_end(struct inode *inode, loff_t offset, loff_t length,
+			  ssize_t written, unsigned flags, struct iomap *iomap)
+{
+	int ret = 0;
+	handle_t *handle;
+	int blkbits = inode->i_blkbits;
+	bool truncate = false;
+
+	if (!(flags & IOMAP_WRITE) || (flags & IOMAP_FAULT))
+		return 0;
+
+	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		goto orphan_del;
+	}
+	if (ext4_update_inode_size(inode, offset + written))
+		ext4_mark_inode_dirty(handle, inode);
+	/*
+	 * We may need to truncate allocated but not written blocks beyond EOF.
+	 */
+	if (iomap->offset + iomap->length > 
+	    ALIGN(inode->i_size, 1 << blkbits)) {
+		ext4_lblk_t written_blk, end_blk;
+
+		written_blk = (offset + written) >> blkbits;
+		end_blk = (offset + length) >> blkbits;
+		if (written_blk < end_blk && ext4_can_truncate(inode))
+			truncate = true;
 	}
 	/*
-	 * At least for now we have to clear BH_New so that DAX code
-	 * doesn't attempt to zero blocks again in a racy way.
+	 * Remove inode from orphan list if we were extending a inode and
+	 * everything went fine.
 	 */
-	clear_buffer_new(bh_result);
-	return 0;
+	if (!truncate && inode->i_nlink &&
+	    !list_empty(&EXT4_I(inode)->i_orphan))
+		ext4_orphan_del(handle, inode);
+	ext4_journal_stop(handle);
+	if (truncate) {
+		ext4_truncate_failed_write(inode);
+orphan_del:
+		/*
+		 * If truncate failed early the inode might still be on the
+		 * orphan list; we need to make sure the inode is removed from
+		 * the orphan list in that case.
+		 */
+		if (inode->i_nlink)
+			ext4_orphan_del(NULL, inode);
+	}
+	return ret;
 }
-#else
-/* Just define empty function, it will never get called. */
-int ext4_dax_get_block(struct inode *inode, sector_t iblock,
-		       struct buffer_head *bh_result, int create)
-{
-	BUG();
-	return 0;
-}
+
+struct iomap_ops ext4_iomap_ops = {
+	.iomap_begin		= ext4_iomap_begin,
+	.iomap_end		= ext4_iomap_end,
+};
+
 #endif
 
 static int ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
···
 	iocb->private = NULL;
 	if (overwrite)
 		get_block_func = ext4_dio_get_block_overwrite;
-	else if (IS_DAX(inode)) {
-		/*
-		 * We can avoid zeroing for aligned DAX writes beyond EOF. Other
-		 * writes need zeroing either because they can race with page
-		 * faults or because they use partial blocks.
-		 */
-		if (round_down(offset, 1<<inode->i_blkbits) >= inode->i_size &&
-		    ext4_aligned_io(inode, offset, count))
-			get_block_func = ext4_dio_get_block;
-		else
-			get_block_func = ext4_dax_get_block;
-		dio_flags = DIO_LOCKING;
-	} else if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) ||
+	else if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) ||
 		   round_down(offset, 1 << inode->i_blkbits) >= inode->i_size) {
 		get_block_func = ext4_dio_get_block;
 		dio_flags = DIO_LOCKING | DIO_SKIP_HOLES;
···
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 	BUG_ON(ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode));
 #endif
-	if (IS_DAX(inode)) {
-		ret = dax_do_io(iocb, inode, iter, get_block_func,
-				ext4_end_io_dio, dio_flags);
-	} else
-		ret = __blockdev_direct_IO(iocb, inode,
-					   inode->i_sb->s_bdev, iter,
-					   get_block_func,
-					   ext4_end_io_dio, NULL, dio_flags);
+	ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
+				   get_block_func, ext4_end_io_dio, NULL,
+				   dio_flags);
 
 	if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
 						EXT4_STATE_DIO_UNWRITTEN)) {
···
 {
 	struct address_space *mapping = iocb->ki_filp->f_mapping;
 	struct inode *inode = mapping->host;
+	size_t count = iov_iter_count(iter);
 	ssize_t ret;
 
 	/*
···
 	 * we are protected against page writeback as well.
 	 */
 	inode_lock_shared(inode);
-	if (IS_DAX(inode)) {
-		ret = dax_do_io(iocb, inode, iter, ext4_dio_get_block, NULL, 0);
-	} else {
-		size_t count = iov_iter_count(iter);
-
-		ret = filemap_write_and_wait_range(mapping, iocb->ki_pos,
-						   iocb->ki_pos + count);
-		if (ret)
-			goto out_unlock;
-		ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
-					   iter, ext4_dio_get_block,
-					   NULL, NULL, 0);
-	}
+	ret = filemap_write_and_wait_range(mapping, iocb->ki_pos,
+					   iocb->ki_pos + count);
+	if (ret)
+		goto out_unlock;
+	ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
+				   iter, ext4_dio_get_block, NULL, NULL, 0);
 out_unlock:
 	inode_unlock_shared(inode);
 	return ret;
···
 
 	/* Let buffer I/O handle the inline data case. */
 	if (ext4_has_inline_data(inode))
+		return 0;
+
+	/* DAX uses iomap path now */
+	if (WARN_ON_ONCE(IS_DAX(inode)))
 		return 0;
 
 	trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
···
 	return __set_page_dirty_nobuffers(page);
 }
 
+static int ext4_set_page_dirty(struct page *page)
+{
+	WARN_ON_ONCE(!PageLocked(page) && !PageDirty(page));
+	WARN_ON_ONCE(!page_has_buffers(page));
+	return __set_page_dirty_buffers(page);
+}
+
 static const struct address_space_operations ext4_aops = {
 	.readpage		= ext4_readpage,
 	.readpages		= ext4_readpages,
···
 	.writepages		= ext4_writepages,
 	.write_begin		= ext4_write_begin,
 	.write_end		= ext4_write_end,
+	.set_page_dirty		= ext4_set_page_dirty,
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_invalidatepage,
 	.releasepage		= ext4_releasepage,
···
 	.writepages		= ext4_writepages,
 	.write_begin		= ext4_da_write_begin,
 	.write_end		= ext4_da_write_end,
+	.set_page_dirty		= ext4_set_page_dirty,
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_da_invalidatepage,
 	.releasepage		= ext4_releasepage,
···
 			/* We expect the key to be set. */
 			BUG_ON(!fscrypt_has_encryption_key(inode));
 			BUG_ON(blocksize != PAGE_SIZE);
-			WARN_ON_ONCE(fscrypt_decrypt_page(page));
+			WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host,
+						page, PAGE_SIZE, 0, page->index));
 		}
 	}
 	if (ext4_should_journal_data(inode)) {
···
 	if (length > max || length < 0)
 		length = max;
 
-	if (IS_DAX(inode))
-		return dax_zero_page_range(inode, from, length, ext4_get_block);
+	if (IS_DAX(inode)) {
+		return iomap_zero_range(inode, from, length, NULL,
+					&ext4_iomap_ops);
+	}
 	return __ext4_block_zero_page_range(handle, mapping, from, length);
 }
 
···
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);
 
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 out_stop:
 	ext4_journal_stop(handle);
···
  * that's fine - as long as they are linked from the inode, the post-crash
  * ext4_truncate() run will find them and release them.
  */
-void ext4_truncate(struct inode *inode)
+int ext4_truncate(struct inode *inode)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	unsigned int credits;
+	int err = 0;
 	handle_t *handle;
 	struct address_space *mapping = inode->i_mapping;
 
···
 	trace_ext4_truncate_enter(inode);
 
 	if (!ext4_can_truncate(inode))
-		return;
+		return 0;
 
 	ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
 
···
 
 		ext4_inline_data_truncate(inode, &has_inline);
 		if (has_inline)
-			return;
+			return 0;
 	}
 
 	/* If we zero-out tail of the page, we have to create jinode for jbd2 */
 	if (inode->i_size & (inode->i_sb->s_blocksize - 1)) {
 		if (ext4_inode_attach_jinode(inode) < 0)
-			return;
+			return 0;
 	}
 
 	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
···
 		credits = ext4_blocks_for_truncate(inode);
 
 	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
-	if (IS_ERR(handle)) {
-		ext4_std_error(inode->i_sb, PTR_ERR(handle));
-		return;
-	}
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
 
 	if (inode->i_size & (inode->i_sb->s_blocksize - 1))
 		ext4_block_truncate_page(handle, mapping, inode->i_size);
···
 	 * Implication: the file must always be in a sane, consistent
 	 * truncatable state while each transaction commits.
 	 */
-	if (ext4_orphan_add(handle, inode))
+	err = ext4_orphan_add(handle, inode);
+	if (err)
 		goto out_stop;
 
 	down_write(&EXT4_I(inode)->i_data_sem);
···
 	ext4_discard_preallocations(inode);
 
 	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
-		ext4_ext_truncate(handle, inode);
+		err = ext4_ext_truncate(handle, inode);
 	else
 		ext4_ind_truncate(handle, inode);
 
 	up_write(&ei->i_data_sem);
+	if (err)
+		goto out_stop;
 
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);
···
 	if (inode->i_nlink)
 		ext4_orphan_del(handle, inode);
 
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 	ext4_journal_stop(handle);
 
 	trace_ext4_truncate_exit(inode);
+	return err;
 }
 
 /*
···
 		new_fl |= S_NOATIME;
 	if (flags & EXT4_DIRSYNC_FL)
 		new_fl |= S_DIRSYNC;
-	if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
+	if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode) &&
+	    !ext4_should_journal_data(inode) && !ext4_has_inline_data(inode) &&
+	    !ext4_encrypted_inode(inode))
 		new_fl |= S_DAX;
 	inode_set_flags(inode, new_fl,
 			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);
···
 {
 	__le32 *magic = (void *)raw_inode +
 			EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
-	if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
+	if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize + sizeof(__le32) <=
+	    EXT4_INODE_SIZE(inode->i_sb) &&
+	    *magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
 		ext4_set_inode_state(inode, EXT4_STATE_XATTR);
 		ext4_find_inline_data_nolock(inode);
 	} else
···
 	struct inode *inode;
 	journal_t *journal = EXT4_SB(sb)->s_journal;
 	long ret;
+	loff_t size;
 	int block;
 	uid_t i_uid;
 	gid_t i_gid;
···
 	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
 		ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
 		if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
-		    EXT4_INODE_SIZE(inode->i_sb)) {
-			EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
-				EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
-				EXT4_INODE_SIZE(inode->i_sb));
+			EXT4_INODE_SIZE(inode->i_sb) ||
+		    (ei->i_extra_isize & 3)) {
+			EXT4_ERROR_INODE(inode,
+					 "bad extra_isize %u (inode size %u)",
+					 ei->i_extra_isize,
+					 EXT4_INODE_SIZE(inode->i_sb));
 			ret = -EFSCORRUPTED;
 			goto bad_inode;
 		}
···
 		ei->i_file_acl |=
 			((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
 	inode->i_size = ext4_isize(raw_inode);
+	if ((size = i_size_read(inode)) < 0) {
+		EXT4_ERROR_INODE(inode, "bad i_size value: %lld", size);
+		ret = -EFSCORRUPTED;
+		goto bad_inode;
+	}
 	ei->i_disksize = inode->i_size;
 #ifdef CONFIG_QUOTA
 	ei->i_reserved_quota = 0;
···
 	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
 		if (ei->i_extra_isize == 0) {
 			/* The extra space is currently unused. Use it. */
+			BUILD_BUG_ON(sizeof(struct ext4_inode) & 3);
 			ei->i_extra_isize = sizeof(struct ext4_inode) -
 					    EXT4_GOOD_OLD_INODE_SIZE;
 		} else {
···
 			 * update c/mtime in shrink case below
 			 */
 			if (!shrink) {
-				inode->i_mtime = ext4_current_time(inode);
+				inode->i_mtime = current_time(inode);
 				inode->i_ctime = inode->i_mtime;
 			}
 			down_write(&EXT4_I(inode)->i_data_sem);
···
 		 * in data=journal mode to make pages freeable.
 		 */
 		truncate_pagecache(inode, inode->i_size);
-		if (shrink)
-			ext4_truncate(inode);
+		if (shrink) {
+			rc = ext4_truncate(inode);
+			if (rc)
+				error = rc;
+		}
 		up_write(&EXT4_I(inode)->i_mmap_sem);
 	}
 
-	if (!rc) {
+	if (!error) {
 		setattr_copy(inode, attr);
 		mark_inode_dirty(inode);
 	}
···
 	if (orphan && inode->i_nlink)
 		ext4_orphan_del(NULL, inode);
 
-	if (!rc && (ia_valid & ATTR_MODE))
+	if (!error && (ia_valid & ATTR_MODE))
 		rc = posix_acl_chmod(inode, inode->i_mode);
 
 err_out:
···
 	err = ext4_reserve_inode_write(handle, inode, &iloc);
 	if (err)
 		return err;
-	if (ext4_handle_valid(handle) &&
-	    EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
+	if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
 	    !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
 		/*
-		 * We need extra buffer credits since we may write into EA block
+		 * In nojournal mode, we can immediately attempt to expand
+		 * the inode.  When journaled, we first need to obtain extra
+		 * buffer credits since we may write into the EA block
 		 * with this same handle. If journal_extend fails, then it will
 		 * only result in a minor loss of functionality for that inode.
 		 * If this is felt to be critical, then e2fsck should be run to
 		 * force a large enough s_min_extra_isize.
 		 */
-		if ((jbd2_journal_extend(handle,
-			     EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
+		if (!ext4_handle_valid(handle) ||
+		    jbd2_journal_extend(handle,
+			     EXT4_DATA_TRANS_BLOCKS(inode->i_sb)) == 0) {
 			ret = ext4_expand_extra_isize(inode,
 						      sbi->s_want_extra_isize,
 						      iloc, handle);
···
 		ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
 	}
 	ext4_set_aops(inode);
+	/*
+	 * Update inode->i_flags after EXT4_INODE_JOURNAL_DATA was updated.
+	 * E.g. S_DAX may get cleared / set.
+	 */
+	ext4_set_inode_flags(inode);
 
 	jbd2_journal_unlock_updates(journal);
 	percpu_up_write(&sbi->s_journal_flag_rwsem);

fs/ext4/ioctl.c

···
 
 	swap_inode_data(inode, inode_bl);
 
-	inode->i_ctime = inode_bl->i_ctime = ext4_current_time(inode);
+	inode->i_ctime = inode_bl->i_ctime = current_time(inode);
 
 	spin_lock(&sbi->s_next_gen_lock);
 	inode->i_generation = sbi->s_next_generation++;
···
 	return err;
 }
 
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
 static int uuid_is_zero(__u8 u[16])
 {
 	int	i;
···
 			return 0;
 	return 1;
 }
+#endif
 
 static int ext4_ioctl_setflags(struct inode *inode,
 			       unsigned int flags)
···
 			err = -EOPNOTSUPP;
 			goto flags_out;
 		}
-	} else if (oldflags & EXT4_EOFBLOCKS_FL)
-		ext4_truncate(inode);
+	} else if (oldflags & EXT4_EOFBLOCKS_FL) {
+		err = ext4_truncate(inode);
+		if (err)
+			goto flags_out;
+	}
 
 	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 	if (IS_ERR(handle)) {
···
 	for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
 		if (!(mask & EXT4_FL_USER_MODIFIABLE))
 			continue;
+		/* These flags get special treatment later */
+		if (mask == EXT4_JOURNAL_DATA_FL || mask == EXT4_EXTENTS_FL)
+			continue;
 		if (mask & flags)
 			ext4_set_inode_flag(inode, i);
 		else
···
 	}
 
 	ext4_set_inode_flags(inode);
-	inode->i_ctime = ext4_current_time(inode);
+	inode->i_ctime = current_time(inode);
 
 	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 flags_err:
···
 	}
 
 	EXT4_I(inode)->i_projid = kprojid;
-	inode->i_ctime = ext4_current_time(inode);
+	inode->i_ctime = current_time(inode);
 out_dirty:
 	rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
 	if (!err)
···
 		xflags |= FS_XFLAG_PROJINHERIT;
 	return xflags;
 }
+
+#define EXT4_SUPPORTED_FS_XFLAGS (FS_XFLAG_SYNC | FS_XFLAG_IMMUTABLE | \
+				  FS_XFLAG_APPEND | FS_XFLAG_NODUMP | \
+				  FS_XFLAG_NOATIME | FS_XFLAG_PROJINHERIT)
 
 /* Transfer xflags flags to internal */
 static inline unsigned long ext4_xflags_to_iflags(__u32 xflags)
···
 		if (get_user(flags, (int __user *) arg))
 			return -EFAULT;
 
+		if (flags & ~EXT4_FL_USER_VISIBLE)
+			return -EOPNOTSUPP;
+		/*
+		 * chattr(1) grabs flags via GETFLAGS, modifies the result and
+		 * passes that to SETFLAGS. So we cannot easily make SETFLAGS
+		 * more restrictive than just silently masking off visible but
+		 * not settable flags as we always did.
+		 */
+		flags &= EXT4_FL_USER_MODIFIABLE;
+		if (ext4_mask_flags(inode->i_mode, flags) != flags)
+			return -EOPNOTSUPP;
+
 		err = mnt_want_write_file(filp);
 		if (err)
 			return err;
-
-		flags = ext4_mask_flags(inode->i_mode, flags);
 
 		inode_lock(inode);
 		err = ext4_ioctl_setflags(inode, flags);
···
 		}
 		err = ext4_reserve_inode_write(handle, inode, &iloc);
 		if (err == 0) {
-			inode->i_ctime = ext4_current_time(inode);
+			inode->i_ctime = current_time(inode);
 			inode->i_generation = generation;
 			err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 		}
···
 	}
 	case EXT4_IOC_PRECACHE_EXTENTS:
 		return ext4_ext_precache(inode);
-	case EXT4_IOC_SET_ENCRYPTION_POLICY: {
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-		struct fscrypt_policy policy;
 
+	case EXT4_IOC_SET_ENCRYPTION_POLICY:
 		if (!ext4_has_feature_encrypt(sb))
 			return -EOPNOTSUPP;
+		return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
 
-		if (copy_from_user(&policy,
-				   (struct fscrypt_policy __user *)arg,
-				   sizeof(policy)))
-			return -EFAULT;
-		return fscrypt_process_policy(filp, &policy);
-#else
-		return -EOPNOTSUPP;
-#endif
-	}
 	case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
 		int err, err2;
 		struct ext4_sb_info *sbi = EXT4_SB(sb);
 		handle_t *handle;
 
-		if (!ext4_sb_has_crypto(sb))
+		if (!ext4_has_feature_encrypt(sb))
 			return -EOPNOTSUPP;
 		if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
 			err = mnt_want_write_file(filp);
···
 				 sbi->s_es->s_encrypt_pw_salt, 16))
 			return -EFAULT;
 		return 0;
-	}
-	case EXT4_IOC_GET_ENCRYPTION_POLICY: {
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-		struct fscrypt_policy policy;
-		int err = 0;
-
-		if (!ext4_encrypted_inode(inode))
-			return -ENOENT;
-		err = fscrypt_get_policy(inode, &policy);
-		if (err)
-			return err;
-		if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))
-			return -EFAULT;
-		return 0;
 #else
 		return -EOPNOTSUPP;
 #endif
 	}
+	case EXT4_IOC_GET_ENCRYPTION_POLICY:
+		return fscrypt_ioctl_get_policy(filp, (void __user *)arg);
+
 	case EXT4_IOC_FSGETXATTR:
 	{
 		struct fsxattr fa;
···
 		if (!inode_owner_or_capable(inode))
 			return -EACCES;
 
+		if (fa.fsx_xflags & ~EXT4_SUPPORTED_FS_XFLAGS)
+			return -EOPNOTSUPP;
+
+		flags = ext4_xflags_to_iflags(fa.fsx_xflags);
+		if (ext4_mask_flags(inode->i_mode, flags) != flags)
+			return -EOPNOTSUPP;
+
 		err = mnt_want_write_file(filp);
 		if (err)
 			return err;
-
-		flags = ext4_xflags_to_iflags(fa.fsx_xflags);
-		flags = ext4_mask_flags(inode->i_mode, flags);
 
 		inode_lock(inode);
 		flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |

fs/ext4/mballoc.c

···
 	ext4_grpblk_t min;
 	ext4_grpblk_t max;
 	ext4_grpblk_t chunk;
-	unsigned short border;
+	unsigned int border;
 
 	BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
 
···
 	struct ext4_group_info *grinfo;
 	struct sg {
 		struct ext4_group_info info;
-		ext4_grpblk_t counters[16];
+		ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
 	} sg;
 
 	group--;

fs/ext4/namei.c

···
 	 * happen is that the times are slightly out of date
 	 * and/or different from the directory change time.
 	 */
-	dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
+	dir->i_mtime = dir->i_ctime = current_time(dir);
 	ext4_update_dx_flag(dir);
 	dir->i_version++;
 	ext4_mark_inode_dirty(handle, dir);
···
 	 * recovery. */
 	inode->i_size = 0;
 	ext4_orphan_add(handle, inode);
-	inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
+	inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 	ext4_dec_count(handle, dir);
 	ext4_update_dx_flag(dir);
···
 	retval = ext4_delete_entry(handle, dir, de, bh);
 	if (retval)
 		goto end_unlink;
-	dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
+	dir->i_ctime = dir->i_mtime = current_time(dir);
 	ext4_update_dx_flag(dir);
 	ext4_mark_inode_dirty(handle, dir);
 	drop_nlink(inode);
 	if (!inode->i_nlink)
 		ext4_orphan_add(handle, inode);
-	inode->i_ctime = ext4_current_time(inode);
+	inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 
 end_unlink:
···
 	if (IS_DIRSYNC(dir))
 		ext4_handle_sync(handle);
 
-	inode->i_ctime = ext4_current_time(inode);
+	inode->i_ctime = current_time(inode);
 	ext4_inc_count(handle, inode);
 	ihold(inode);
 
···
 		ent->de->file_type = file_type;
 	ent->dir->i_version++;
 	ent->dir->i_ctime = ent->dir->i_mtime =
-		ext4_current_time(ent->dir);
+		current_time(ent->dir);
 	ext4_mark_inode_dirty(handle, ent->dir);
 	BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
 	if (!ent->inlined) {
···
 	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
 	 */
-	old.inode->i_ctime = ext4_current_time(old.inode);
+	old.inode->i_ctime = current_time(old.inode);
 	ext4_mark_inode_dirty(handle, old.inode);
 
 	if (!whiteout) {
···
 
 	if (new.inode) {
 		ext4_dec_count(handle, new.inode);
-		new.inode->i_ctime = ext4_current_time(new.inode);
+		new.inode->i_ctime = current_time(new.inode);
 	}
-	old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
+	old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
 	ext4_update_dx_flag(old.dir);
 	if (old.dir_bh) {
 		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
···
 	};
 	u8 new_file_type;
 	int retval;
+	struct timespec ctime;
 
 	if ((ext4_encrypted_inode(old_dir) ||
 	     ext4_encrypted_inode(new_dir)) &&
···
 	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
 	 */
-	old.inode->i_ctime = ext4_current_time(old.inode);
-	new.inode->i_ctime = ext4_current_time(new.inode);
+	ctime = current_time(old.inode);
+	old.inode->i_ctime = ctime;
+	new.inode->i_ctime = ctime;
 	ext4_mark_inode_dirty(handle, old.inode);
 	ext4_mark_inode_dirty(handle, new.inode);
 

fs/ext4/page-io.c

···
 		gfp_t gfp_flags = GFP_NOFS;
 
 	retry_encrypt:
-		data_page = fscrypt_encrypt_page(inode, page, gfp_flags);
+		data_page = fscrypt_encrypt_page(inode, page, PAGE_SIZE, 0,
+						page->index, gfp_flags);
 		if (IS_ERR(data_page)) {
 			ret = PTR_ERR(data_page);
 			if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {

fs/ext4/super.c

···
 	percpu_counter_destroy(&sbi->s_dirs_counter);
 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
-	brelse(sbi->s_sbh);
 #ifdef CONFIG_QUOTA
 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
 		kfree(sbi->s_qf_names[i]);
···
 	}
 	if (sbi->s_mmp_tsk)
 		kthread_stop(sbi->s_mmp_tsk);
+	brelse(sbi->s_sbh);
 	sb->s_fs_info = NULL;
 	/*
 	 * Now that we are completely done shutting down the
···
 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
 							void *fs_data)
 {
-	handle_t *handle;
-	int res, res2;
+	handle_t *handle = fs_data;
+	int res, res2, retries = 0;
 
-	/* fs_data is null when internally used. */
-	if (fs_data) {
-		res  = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-				EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
-				len, 0);
+	/*
+	 * If a journal handle was specified, then the encryption context is
+	 * being set on a new inode via inheritance and is part of a larger
+	 * transaction to create the inode.  Otherwise the encryption context is
+	 * being set on an existing inode in its own transaction.  Only in the
+	 * latter case should the "retry on ENOSPC" logic be used.
+	 */
+
+	if (handle) {
+		res = ext4_xattr_set_handle(handle, inode,
+					    EXT4_XATTR_INDEX_ENCRYPTION,
+					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
+					    ctx, len, 0);
 		if (!res) {
 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
 			ext4_clear_inode_state(inode,
 					EXT4_STATE_MAY_INLINE_DATA);
+			/*
+			 * Update inode->i_flags - e.g. S_DAX may get disabled
+			 */
+			ext4_set_inode_flags(inode);
 		}
 		return res;
 	}
 
+retry:
 	handle = ext4_journal_start(inode, EXT4_HT_MISC,
 			ext4_jbd2_credits_xattr(inode));
 	if (IS_ERR(handle))
 		return PTR_ERR(handle);
 
-	res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-			EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
-			len, 0);
+	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
+				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
+				    ctx, len, 0);
 	if (!res) {
 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
+		/* Update inode->i_flags - e.g. S_DAX may get disabled */
+		ext4_set_inode_flags(inode);
 		res = ext4_mark_inode_dirty(handle, inode);
 		if (res)
 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
 	}
 	res2 = ext4_journal_stop(handle);
+
+	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+		goto retry;
 	if (!res)
 		res = res2;
 	return res;
···
 			return 0;
 		}
 	}
-	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
-	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
-		ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
-			 "in data=ordered mode");
-		return 0;
-	}
 	return 1;
 }
 
···
 				struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
-	int nr_orphans = 0, nr_truncates = 0;
+	int ret, nr_orphans = 0, nr_truncates = 0;
 #ifdef CONFIG_QUOTA
 	int i;
 #endif
···
 				  inode->i_ino, inode->i_size);
 			inode_lock(inode);
 			truncate_inode_pages(inode->i_mapping, inode->i_size);
-			ext4_truncate(inode);
+			ret = ext4_truncate(inode);
+			if (ret)
+				ext4_std_error(inode->i_sb, ret);
 			inode_unlock(inode);
 			nr_truncates++;
 		} else {
···
 			ext4_set_bit(s++, buf);
 			count++;
 		}
-		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
-			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
-			count++;
+		j = ext4_bg_num_gdb(sb, grp);
+		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
+			ext4_error(sb, "Invalid number of block group "
+				   "descriptor blocks: %d", j);
+			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
 		}
+		count += j;
+		for (; j > 0; j--)
+			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
 	}
 	if (!count)
 		return 0;
···
 	char *orig_data = kstrdup(data, GFP_KERNEL);
 	struct buffer_head *bh;
 	struct ext4_super_block *es = NULL;
-	struct ext4_sb_info *sbi;
+	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	ext4_fsblk_t block;
 	ext4_fsblk_t sb_block = get_sb_block(&data);
 	ext4_fsblk_t logical_sb_block;
···
 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
 	ext4_group_t first_not_zeroed;
 
-	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
-	if (!sbi)
-		goto out_free_orig;
+	if ((data && !orig_data) || !sbi)
+		goto out_free_base;
 
 	sbi->s_blockgroup_lock =
 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
-	if (!sbi->s_blockgroup_lock) {
-		kfree(sbi);
-		goto out_free_orig;
-	}
+	if (!sbi->s_blockgroup_lock)
+		goto out_free_base;
+
 	sb->s_fs_info = sbi;
 	sbi->s_sb = sb;
 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
···
 	 */
 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
 
-	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
-			   &journal_devnum, &journal_ioprio, 0)) {
-		ext4_msg(sb, KERN_WARNING,
-			 "failed to parse options in superblock: %s",
-			 sbi->s_es->s_mount_opts);
+	if (sbi->s_es->s_mount_opts[0]) {
+		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
+					      sizeof(sbi->s_es->s_mount_opts),
+					      GFP_KERNEL);
+		if (!s_mount_opts)
+			goto failed_mount;
+		if (!parse_options(s_mount_opts, sb, &journal_devnum,
+				   &journal_ioprio, 0)) {
+			ext4_msg(sb, KERN_WARNING,
+				 "failed to parse options in superblock: %s",
+				 s_mount_opts);
+		}
+		kfree(s_mount_opts);
 	}
 	sbi->s_def_mount_opt = sbi->s_mount_opt;
 	if (!parse_options((char *) data, sb, &journal_devnum,
···
 			ext4_msg(sb, KERN_ERR, "can't mount with "
 				 "both data=journal and dax");
 			goto failed_mount;
+		}
+		if (ext4_has_feature_encrypt(sb)) {
+			ext4_msg(sb, KERN_WARNING,
+				 "encrypted files will use data=ordered "
+				 "instead of data journaling mode");
 		}
 		if (test_opt(sb, DELALLOC))
 			clear_opt(sb, DELALLOC);
···
 
 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
-	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
-		goto cantfind_ext4;
 
 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
 	if (sbi->s_inodes_per_block == 0)
 		goto cantfind_ext4;
+	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
+	    sbi->s_inodes_per_group > blocksize * 8) {
+		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
+			 sbi->s_blocks_per_group);
+		goto failed_mount;
+	}
 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
 					sbi->s_inodes_per_block;
 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
···
 	}
 	sbi->s_cluster_ratio = clustersize / blocksize;
 
-	if (sbi->s_inodes_per_group > blocksize * 8) {
-		ext4_msg(sb, KERN_ERR,
-		       "#inodes per group too big: %lu",
-		       sbi->s_inodes_per_group);
-		goto failed_mount;
-	}
-
 	/* Do we have standard group size of clustersize * 8 blocks ? */
 	if (sbi->s_blocks_per_group == clustersize << 3)
 		set_opt2(sb, STD_GROUP_SIZE);
···
 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
 		   EXT4_DESC_PER_BLOCK(sb);
+	if (ext4_has_feature_meta_bg(sb)) {
+		if (le32_to_cpu(es->s_first_meta_bg) >= db_count) {
+			ext4_msg(sb, KERN_WARNING,
+				 "first meta block group too large: %u "
+				 "(group descriptor block count %u)",
+				 le32_to_cpu(es->s_first_meta_bg), db_count);
+			goto failed_mount;
+		}
+	}
 	sbi->s_group_desc = ext4_kvmalloc(db_count *
 					  sizeof(struct buffer_head *),
 					  GFP_KERNEL);
···
 	default:
 		break;
 	}
+
+	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
+	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+		ext4_msg(sb, KERN_ERR, "can't mount with "
+			"journal_async_commit in data=ordered mode");
+		goto failed_mount_wq;
+	}
+
 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
 
 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
···
 
 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
-			 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
+			 "Opts: %.*s%s%s", descr,
+			 (int) sizeof(sbi->s_es->s_mount_opts),
+			 sbi->s_es->s_mount_opts,
 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
 
 	if (es->s_error_count)
···
 out_fail:
 	sb->s_fs_info = NULL;
 	kfree(sbi->s_blockgroup_lock);
+out_free_base:
 	kfree(sbi);
-out_free_orig:
 	kfree(orig_data);
 	return err ? err : ret;
 }
···
 				&EXT4_SB(sb)->s_freeinodes_counter));
 	BUFFER_TRACE(sbh, "marking dirty");
 	ext4_superblock_csum_set(sb);
-	lock_buffer(sbh);
+	if (sync)
+		lock_buffer(sbh);
 	if (buffer_write_io_error(sbh)) {
 		/*
 		 * Oh, dear.  A previous attempt to write the
···
 		set_buffer_uptodate(sbh);
 	}
 	mark_buffer_dirty(sbh);
-	unlock_buffer(sbh);
 	if (sync) {
+		unlock_buffer(sbh);
 		error = __sync_dirty_buffer(sbh,
 			test_opt(sb, BARRIER) ? REQ_FUA : REQ_SYNC);
 		if (error)
···
 		if (test_opt(sb, DAX)) {
 			ext4_msg(sb, KERN_ERR, "can't mount with "
 				 "both data=journal and dax");
+			err = -EINVAL;
+			goto restore_opts;
+		}
+	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
+		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+			ext4_msg(sb, KERN_ERR, "can't mount with "
+				"journal_async_commit in data=ordered mode");
 			err = -EINVAL;
 			goto restore_opts;
 		}
···
 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
 	if (IS_ERR(handle))
 		goto out;
-	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 	ext4_journal_stop(handle);
 

fs/ext4/xattr.c

···
 {
 	struct ext4_xattr_entry *e = entry;
 
+	/* Find the end of the names list */
 	while (!IS_LAST_ENTRY(e)) {
 		struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
 		if ((void *)next >= end)
···
 		e = next;
 	}
 
+	/* Check the values */
 	while (!IS_LAST_ENTRY(entry)) {
 		if (entry->e_value_block != 0)
 			return -EFSCORRUPTED;
-		if (entry->e_value_size != 0 &&
-		    (value_start + le16_to_cpu(entry->e_value_offs) <
-		     (void *)e + sizeof(__u32) ||
-		     value_start + le16_to_cpu(entry->e_value_offs) +
-		    le32_to_cpu(entry->e_value_size) > end))
-			return -EFSCORRUPTED;
+		if (entry->e_value_size != 0) {
+			u16 offs = le16_to_cpu(entry->e_value_offs);
+			u32 size = le32_to_cpu(entry->e_value_size);
+			void *value;
+
+			/*
+			 * The value cannot overlap the names, and the value
+			 * with padding cannot extend beyond 'end'.  Check both
+			 * the padded and unpadded sizes, since the size may
+			 * overflow to 0 when adding padding.
+			 */
+			if (offs > end - value_start)
+				return -EFSCORRUPTED;
+			value = value_start + offs;
+			if (value < (void *)e + sizeof(u32) ||
+			    size > end - value ||
+			    EXT4_XATTR_SIZE(size) > end - value)
+				return -EFSCORRUPTED;
+		}
 		entry = EXT4_XATTR_NEXT(entry);
 	}
 
···
 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
 			 void *end, const char *function, unsigned int line)
 {
-	struct ext4_xattr_entry *entry = IFIRST(header);
 	int error = -EFSCORRUPTED;
 
-	if (((void *) header >= end) ||
+	if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
 	    (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
 		goto errout;
-	error = ext4_xattr_check_names(entry, end, entry);
+	error = ext4_xattr_check_names(IFIRST(header), end, IFIRST(header));
 errout:
 	if (error)
 		__ext4_error_inode(inode, function, line, 0,
···
 	return 0;
 }
 
-static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
+static int ext4_xattr_ibody_set(struct inode *inode,
 				struct ext4_xattr_info *i,
 				struct ext4_xattr_ibody_find *is)
 {
···
 	}
 	if (!value) {
 		if (!is.s.not_found)
-			error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+			error = ext4_xattr_ibody_set(inode, &i, &is);
 		else if (!bs.s.not_found)
 			error = ext4_xattr_block_set(handle, inode, &i, &bs);
 	} else {
···
 		if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
 			goto cleanup;
 
-		error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+		error = ext4_xattr_ibody_set(inode, &i, &is);
 		if (!error && !bs.s.not_found) {
 			i.value = NULL;
 			error = ext4_xattr_block_set(handle, inode, &i, &bs);
···
 				goto cleanup;
 			if (!is.s.not_found) {
 				i.value = NULL;
-				error = ext4_xattr_ibody_set(handle, inode, &i,
-							     &is);
+				error = ext4_xattr_ibody_set(inode, &i, &is);
 			}
 		}
 	}
 	if (!error) {
 		ext4_xattr_update_super_block(handle, inode->i_sb);
-		inode->i_ctime = ext4_current_time(inode);
+		inode->i_ctime = current_time(inode);
 		if (!value)
 			ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
 		error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
···
 		goto out;
 
 	/* Remove the chosen entry from the inode */
-	error = ext4_xattr_ibody_set(handle, inode, &i, is);
+	error = ext4_xattr_ibody_set(inode, &i, is);
 	if (error)
 		goto out;
 

fs/f2fs/data.c

···
 							fio->old_blkaddr);
 retry_encrypt:
 		fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
-								gfp_flags);
+							PAGE_SIZE, 0,
+							fio->page->index,
+							gfp_flags);
 		if (IS_ERR(fio->encrypted_page)) {
 			err = PTR_ERR(fio->encrypted_page);
 			if (err == -ENOMEM) {

fs/f2fs/f2fs.h

···
 #define fscrypt_pullback_bio_page	fscrypt_notsupp_pullback_bio_page
 #define fscrypt_restore_control_page	fscrypt_notsupp_restore_control_page
 #define fscrypt_zeroout_range		fscrypt_notsupp_zeroout_range
-#define fscrypt_process_policy		fscrypt_notsupp_process_policy
-#define fscrypt_get_policy		fscrypt_notsupp_get_policy
+#define fscrypt_ioctl_set_policy	fscrypt_notsupp_ioctl_set_policy
+#define fscrypt_ioctl_get_policy	fscrypt_notsupp_ioctl_get_policy
 #define fscrypt_has_permitted_context	fscrypt_notsupp_has_permitted_context
 #define fscrypt_inherit_context		fscrypt_notsupp_inherit_context
 #define fscrypt_get_encryption_info	fscrypt_notsupp_get_encryption_info

fs/f2fs/file.c

···
 
 static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg)
 {
-	struct fscrypt_policy policy;
 	struct inode *inode = file_inode(filp);
-
-	if (copy_from_user(&policy, (struct fscrypt_policy __user *)arg,
-							sizeof(policy)))
-		return -EFAULT;
 
 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 
-	return fscrypt_process_policy(filp, &policy);
+	return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
 }
 
 static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg)
 {
-	struct fscrypt_policy policy;
-	struct inode *inode = file_inode(filp);
-	int err;
-
-	err = fscrypt_get_policy(inode, &policy);
-	if (err)
-		return err;
-
-	if (copy_to_user((struct fscrypt_policy __user *)arg, &policy, sizeof(policy)))
-		return -EFAULT;
-	return 0;
+	return fscrypt_ioctl_get_policy(filp, (void __user *)arg);
 }
 
 static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)

fs/iomap.c

···
 
 	offset = page_offset(page);
 	while (length > 0) {
-		ret = iomap_apply(inode, offset, length, IOMAP_WRITE,
-				ops, page, iomap_page_mkwrite_actor);
+		ret = iomap_apply(inode, offset, length,
+				IOMAP_WRITE | IOMAP_FAULT, ops, page,
+				iomap_page_mkwrite_actor);
 		if (unlikely(ret <= 0))
 			goto out_unlock;
 		offset += ret;

fs/mbcache.c

···
 	/* log2 of hash table size */
 	int			c_bucket_bits;
 	/* Maximum entries in cache to avoid degrading hash too much */
-	int			c_max_entries;
+	unsigned long		c_max_entries;
 	/* Protects c_list, c_entry_count */
 	spinlock_t		c_list_lock;
 	struct list_head	c_list;
···
 static struct kmem_cache *mb_entry_cache;
 
 static unsigned long mb_cache_shrink(struct mb_cache *cache,
-				     unsigned int nr_to_scan);
+				     unsigned long nr_to_scan);
 
 static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache,
 							u32 key)
···
 }
 
 /*
- * mb_cache_entry_find_first - find the first entry in cache with given key
+ * mb_cache_entry_find_first - find the first reusable entry with the given key
  * @cache: cache where we should search
  * @key: key to look for
  *
- * Search in @cache for entry with key @key. Grabs reference to the first
- * entry found and returns the entry.
+ * Search in @cache for a reusable entry with key @key. Grabs reference to the
+ * first reusable entry found and returns the entry.
  */
 struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
 						 u32 key)
···
 EXPORT_SYMBOL(mb_cache_entry_find_first);
 
 /*
- * mb_cache_entry_find_next - find next entry in cache with the same
+ * mb_cache_entry_find_next - find next reusable entry with the same key
  * @cache: cache where we should search
  * @entry: entry to start search from
  *
- * Finds next entry in the hash chain which has the same key as @entry.
- * If @entry is unhashed (which can happen when deletion of entry races
- * with the search), finds the first entry in the hash chain. The function
- * drops reference to @entry and returns with a reference to the found entry.
+ * Finds next reusable entry in the hash chain which has the same key as @entry.
+ * If @entry is unhashed (which can happen when deletion of entry races with the
+ * search), finds the first reusable entry in the hash chain. The function drops
+ * reference to @entry and returns with a reference to the found entry.
  */
 struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
 						struct mb_cache_entry *entry)
···
 
 /* Shrink number of entries in cache */
 static unsigned long mb_cache_shrink(struct mb_cache *cache,
-				     unsigned int nr_to_scan)
+				     unsigned long nr_to_scan)
 {
 	struct mb_cache_entry *entry;
 	struct hlist_bl_head *head;
-	unsigned int shrunk = 0;
+	unsigned long shrunk = 0;
 
 	spin_lock(&cache->c_list_lock);
 	while (nr_to_scan-- && !list_empty(&cache->c_list)) {
···
 					 struct mb_cache_entry, e_list);
 		if (entry->e_referenced) {
 			entry->e_referenced = 0;
-			list_move_tail(&cache->c_list, &entry->e_list);
+			list_move_tail(&entry->e_list, &cache->c_list);
 			continue;
 		}
 		list_del_init(&entry->e_list);
···
 static unsigned long mb_cache_scan(struct shrinker *shrink,
 				   struct shrink_control *sc)
 {
-	int nr_to_scan = sc->nr_to_scan;
 	struct mb_cache *cache = container_of(shrink, struct mb_cache,
 					      c_shrink);
-	return mb_cache_shrink(cache, nr_to_scan);
+	return mb_cache_shrink(cache, sc->nr_to_scan);
 }
 
 /* We shrink 1/X of the cache when we have too many entries in it */
···
 struct mb_cache *mb_cache_create(int bucket_bits)
 {
 	struct mb_cache *cache;
-	int bucket_count = 1 << bucket_bits;
-	int i;
-
-	if (!try_module_get(THIS_MODULE))
-		return NULL;
+	unsigned long bucket_count = 1UL << bucket_bits;
+	unsigned long i;
 
 	cache = kzalloc(sizeof(struct mb_cache), GFP_KERNEL);
 	if (!cache)
···
 	return cache;
 
 err_out:
-	module_put(THIS_MODULE);
 	return NULL;
 }
 EXPORT_SYMBOL(mb_cache_create);
···
 	}
 	kfree(cache->c_hash);
 	kfree(cache);
-	module_put(THIS_MODULE);
 }
 EXPORT_SYMBOL(mb_cache_destroy);
 
···
 	mb_entry_cache = kmem_cache_create("mbcache",
 				sizeof(struct mb_cache_entry), 0,
 				SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
-	BUG_ON(!mb_entry_cache);
+	if (!mb_entry_cache)
+		return -ENOMEM;
 	return 0;
 }
 

fs/xfs/xfs_aops.c

···
 	sector_t		iblock,
 	struct buffer_head	*bh_result,
 	int			create,
-	bool			direct,
-	bool			dax_fault)
+	bool			direct)
 {
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
···
 		if (ISUNWRITTEN(&imap))
 			set_buffer_unwritten(bh_result);
 		/* direct IO needs special help */
-		if (create) {
-			if (dax_fault)
-				ASSERT(!ISUNWRITTEN(&imap));
-			else
-				xfs_map_direct(inode, bh_result, &imap, offset,
-						is_cow);
-		}
+		if (create)
+			xfs_map_direct(inode, bh_result, &imap, offset, is_cow);
 	}
 
 	/*
···
 	struct buffer_head	*bh_result,
 	int			create)
 {
-	return __xfs_get_blocks(inode, iblock, bh_result, create, false, false);
+	return __xfs_get_blocks(inode, iblock, bh_result, create, false);
 }
 
 int
···
 	struct buffer_head	*bh_result,
 	int			create)
 {
-	return __xfs_get_blocks(inode, iblock, bh_result, create, true, false);
-}
-
-int
-xfs_get_blocks_dax_fault(
-	struct inode		*inode,
-	sector_t		iblock,
-	struct buffer_head	*bh_result,
-	int			create)
-{
-	return __xfs_get_blocks(inode, iblock, bh_result, create, true, true);
+	return __xfs_get_blocks(inode, iblock, bh_result, create, true);
 }
 
 /*

fs/xfs/xfs_aops.h

···
 		       struct buffer_head *map_bh, int create);
 int	xfs_get_blocks_direct(struct inode *inode, sector_t offset,
 			      struct buffer_head *map_bh, int create);
-int	xfs_get_blocks_dax_fault(struct inode *inode, sector_t offset,
-			         struct buffer_head *map_bh, int create);
-
 int	xfs_end_io_direct_write(struct kiocb *iocb, loff_t offset,
 		ssize_t size, void *private);
 int	xfs_setfilesize(struct xfs_inode *ip, xfs_off_t offset, size_t size);

fs/xfs/xfs_file.c

···
 		return 0; /* skip atime */
 
 	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
-	ret = iomap_dax_rw(iocb, to, &xfs_iomap_ops);
+	ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
 	xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
 
 	file_accessed(iocb->ki_filp);
···
 
 	trace_xfs_file_dax_write(ip, count, pos);
 
-	ret = iomap_dax_rw(iocb, from, &xfs_iomap_ops);
+	ret = dax_iomap_rw(iocb, from, &xfs_iomap_ops);
 	if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
 		i_size_write(inode, iocb->ki_pos);
 		error = xfs_setfilesize(ip, pos, ret);
···
 	xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
 
 	if (IS_DAX(inode)) {
-		ret = iomap_dax_fault(vma, vmf, &xfs_iomap_ops);
+		ret = dax_iomap_fault(vma, vmf, &xfs_iomap_ops);
 	} else {
 		ret = iomap_page_mkwrite(vma, vmf, &xfs_iomap_ops);
 		ret = block_page_mkwrite_return(ret);
···
 		 * changes to xfs_get_blocks_direct() to map unwritten extent
 		 * ioend for conversion on read-only mappings.
 		 */
-		ret = iomap_dax_fault(vma, vmf, &xfs_iomap_ops);
+		ret = dax_iomap_fault(vma, vmf, &xfs_iomap_ops);
 	} else
 		ret = filemap_fault(vma, vmf);
 	xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
···
 	}
 
 	xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
-	ret = dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault);
+	ret = dax_iomap_pmd_fault(vma, addr, pmd, flags, &xfs_iomap_ops);
 	xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
 
 	if (flags & FAULT_FLAG_WRITE)

include/linux/dax.h

···
 
 struct iomap_ops;
 
-/* We use lowest available exceptional entry bit for locking */
+/*
+ * We use lowest available bit in exceptional entry for locking, one bit for
+ * the entry size (PMD) and two more to tell us if the entry is a huge zero
+ * page (HZP) or an empty entry that is just used for locking.  In total four
+ * special bits.
+ *
+ * If the PMD bit isn't set the entry has size PAGE_SIZE, and if the HZP and
+ * EMPTY bits aren't set the entry is a normal DAX entry with a filesystem
+ * block allocation.
+ */
+#define RADIX_DAX_SHIFT	(RADIX_TREE_EXCEPTIONAL_SHIFT + 4)
 #define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
+#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
+#define RADIX_DAX_HZP (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
+#define RADIX_DAX_EMPTY (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3))
 
-ssize_t iomap_dax_rw(struct kiocb *iocb, struct iov_iter *iter,
+static inline unsigned long dax_radix_sector(void *entry)
+{
+	return (unsigned long)entry >> RADIX_DAX_SHIFT;
+}
+
+static inline void *dax_radix_locked_entry(sector_t sector, unsigned long flags)
+{
+	return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags |
+			((unsigned long)sector << RADIX_DAX_SHIFT) |
+			RADIX_DAX_ENTRY_LOCK);
+}
+
+ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
 		struct iomap_ops *ops);
-ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *,
-		  get_block_t, dio_iodone_t, int flags);
-int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t);
-int dax_truncate_page(struct inode *, loff_t from, get_block_t);
-int iomap_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
+int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 			struct iomap_ops *ops);
-int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
 void dax_wake_mapping_entry_waiter(struct address_space *mapping,
-				   pgoff_t index, bool wake_all);
+		pgoff_t index, void *entry, bool wake_all);
 
 #ifdef CONFIG_FS_DAX
 struct page *read_dax_sector(struct block_device *bdev, sector_t n);
···
 }
 #endif
 
-#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
-int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
-				unsigned int flags, get_block_t);
+#ifdef CONFIG_FS_DAX_PMD
+static inline unsigned int dax_radix_order(void *entry)
+{
+	if ((unsigned long)entry & RADIX_DAX_PMD)
+		return PMD_SHIFT - PAGE_SHIFT;
+	return 0;
+}
+int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address,
+		pmd_t *pmd, unsigned int flags, struct iomap_ops *ops);
 #else
-static inline int dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
-				pmd_t *pmd, unsigned int flags, get_block_t gb)
+static inline unsigned int dax_radix_order(void *entry)
+{
+	return 0;
+}
+static inline int dax_iomap_pmd_fault(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmd, unsigned int flags,
+		struct iomap_ops *ops)
 {
 	return VM_FAULT_FALLBACK;
 }
 #endif
 int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *);
-#define dax_mkwrite(vma, vmf, gb)	dax_fault(vma, vmf, gb)
 
 static inline bool vma_is_dax(struct vm_area_struct *vma)
 {

include/linux/fscrypto.h

···
 #include <crypto/skcipher.h>
 #include <uapi/linux/fs.h>
 
-#define FS_KEY_DERIVATION_NONCE_SIZE		16
-#define FS_ENCRYPTION_CONTEXT_FORMAT_V1		1
+#define FS_CRYPTO_BLOCK_SIZE		16
 
-#define FS_POLICY_FLAGS_PAD_4		0x00
-#define FS_POLICY_FLAGS_PAD_8		0x01
-#define FS_POLICY_FLAGS_PAD_16		0x02
-#define FS_POLICY_FLAGS_PAD_32		0x03
-#define FS_POLICY_FLAGS_PAD_MASK	0x03
-#define FS_POLICY_FLAGS_VALID		0x03
-
-/* Encryption algorithms */
-#define FS_ENCRYPTION_MODE_INVALID		0
-#define FS_ENCRYPTION_MODE_AES_256_XTS		1
-#define FS_ENCRYPTION_MODE_AES_256_GCM		2
-#define FS_ENCRYPTION_MODE_AES_256_CBC		3
-#define FS_ENCRYPTION_MODE_AES_256_CTS		4
-
-/**
- * Encryption context for inode
- *
- * Protector format:
- *  1 byte: Protector format (1 = this version)
- *  1 byte: File contents encryption mode
- *  1 byte: File names encryption mode
- *  1 byte: Flags
- *  8 bytes: Master Key descriptor
- *  16 bytes: Encryption Key derivation nonce
- */
-struct fscrypt_context {
-	u8 format;
-	u8 contents_encryption_mode;
-	u8 filenames_encryption_mode;
-	u8 flags;
-	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
-	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
-} __packed;
-
-/* Encryption parameters */
-#define FS_XTS_TWEAK_SIZE		16
-#define FS_AES_128_ECB_KEY_SIZE		16
-#define FS_AES_256_GCM_KEY_SIZE		32
-#define FS_AES_256_CBC_KEY_SIZE		32
-#define FS_AES_256_CTS_KEY_SIZE		32
-#define FS_AES_256_XTS_KEY_SIZE		64
-#define FS_MAX_KEY_SIZE			64
-
-#define FS_KEY_DESC_PREFIX		"fscrypt:"
-#define FS_KEY_DESC_PREFIX_SIZE		8
-
-/* This is passed in from userspace into the kernel keyring */
-struct fscrypt_key {
-	u32 mode;
-	u8 raw[FS_MAX_KEY_SIZE];
-	u32 size;
-} __packed;
-
-struct fscrypt_info {
-	u8 ci_data_mode;
-	u8 ci_filename_mode;
-	u8 ci_flags;
-	struct crypto_skcipher *ci_ctfm;
-	struct key *ci_keyring_key;
-	u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
-};
-
-#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL		0x00000001
-#define FS_WRITE_PATH_FL			0x00000002
+struct fscrypt_info;
 
 struct fscrypt_ctx {
 	union {
···
 	u8 flags;				/* Flags */
 	u8 mode;				/* Encryption mode for tfm */
 };
-
-struct fscrypt_completion_result {
-	struct completion completion;
-	int res;
-};
-
-#define DECLARE_FS_COMPLETION_RESULT(ecr) \
-	struct fscrypt_completion_result ecr = { \
-		COMPLETION_INITIALIZER((ecr).completion), 0 }
-
-#define FS_FNAME_NUM_SCATTER_ENTRIES	4
-#define FS_CRYPTO_BLOCK_SIZE		16
-#define FS_FNAME_CRYPTO_DIGEST_SIZE	32
 
 /**
  * For encrypted symlinks, the ciphertext length is stored at the beginning
···
 #define fname_len(p)		((p)->disk_name.len)
 
 /*
+ * fscrypt superblock flags
+ */
+#define FS_CFLG_OWN_PAGES (1U << 1)
+
+/*
  * crypto opertions for filesystems
  */
 struct fscrypt_operations {
+	unsigned int flags;
 	int (*get_context)(struct inode *, void *, size_t);
 	int (*key_prefix)(struct inode *, u8 **);
 	int (*prepare_context)(struct inode *);
···
 #endif
 }
 
-static inline int fscrypt_has_encryption_key(struct inode *inode)
+static inline int fscrypt_has_encryption_key(const struct inode *inode)
 {
 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 	return (inode->i_crypt_info != NULL);
···
 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 /* crypto.c */
 extern struct kmem_cache *fscrypt_info_cachep;
-int fscrypt_initialize(void);
-
-extern struct fscrypt_ctx *fscrypt_get_ctx(struct inode *, gfp_t);
+extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
 extern void fscrypt_release_ctx(struct fscrypt_ctx *);
-extern struct page *fscrypt_encrypt_page(struct inode *, struct page *, gfp_t);
-extern int fscrypt_decrypt_page(struct page *);
+extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
+						unsigned int, unsigned int,
+						u64, gfp_t);
+extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
+				unsigned int, u64);
 extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *);
 extern void fscrypt_pullback_bio_page(struct page **, bool);
 extern void fscrypt_restore_control_page(struct page *);
-extern int fscrypt_zeroout_range(struct inode *, pgoff_t, sector_t,
+extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
 						unsigned int);
 /* policy.c */
-extern int fscrypt_process_policy(struct file *, const struct fscrypt_policy *);
-extern int fscrypt_get_policy(struct inode *, struct fscrypt_policy *);
+extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
+extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
 extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
 extern int fscrypt_inherit_context(struct inode *, struct inode *,
 					void *, bool);
 /* keyinfo.c */
-extern int get_crypt_info(struct inode *);
 extern int fscrypt_get_encryption_info(struct inode *);
 extern void fscrypt_put_encryption_info(struct inode *, struct fscrypt_info *);
 
···
 extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
 				int lookup, struct fscrypt_name *);
 extern void fscrypt_free_filename(struct fscrypt_name *);
-extern u32 fscrypt_fname_encrypted_size(struct inode *, u32);
-extern int fscrypt_fname_alloc_buffer(struct inode *, u32,
+extern u32 fscrypt_fname_encrypted_size(const struct inode *, u32);
+extern int fscrypt_fname_alloc_buffer(const struct inode *, u32,
 				struct fscrypt_str *);
 extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
 extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
···
 #endif
 
 /* crypto.c */
-static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(struct inode *i,
+static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(const struct inode *i,
 							gfp_t f)
 {
 	return ERR_PTR(-EOPNOTSUPP);
···
 	return;
 }
 
-static inline struct page *fscrypt_notsupp_encrypt_page(struct inode *i,
-						struct page *p, gfp_t f)
+static inline struct page *fscrypt_notsupp_encrypt_page(const struct inode *i,
+						struct page *p,
+						unsigned int len,
+						unsigned int offs,
+						u64 lblk_num, gfp_t f)
 {
 	return ERR_PTR(-EOPNOTSUPP);
 }
 
-static inline int fscrypt_notsupp_decrypt_page(struct page *p)
+static inline int fscrypt_notsupp_decrypt_page(const struct inode *i, struct page *p,
+						unsigned int len, unsigned int offs,
+						u64 lblk_num)
 {
 	return -EOPNOTSUPP;
 }
···
 	return;
 }
 
-static inline int fscrypt_notsupp_zeroout_range(struct inode *i, pgoff_t p,
+static inline int fscrypt_notsupp_zeroout_range(const struct inode *i, pgoff_t p,
 					sector_t s, unsigned int f)
 {
 	return -EOPNOTSUPP;
 }
 
 /* policy.c */
-static inline int fscrypt_notsupp_process_policy(struct file *f,
-				const struct fscrypt_policy *p)
+static inline int fscrypt_notsupp_ioctl_set_policy(struct file *f,
+				const void __user *arg)
 {
 	return -EOPNOTSUPP;
 }
 
-static inline int fscrypt_notsupp_get_policy(struct inode *i,
-				struct fscrypt_policy *p)
+static inline int fscrypt_notsupp_ioctl_get_policy(struct file *f,
+				void __user *arg)
 {
 	return -EOPNOTSUPP;
 }

include/linux/iomap.h

···
 #define IOMAP_WRITE		(1 << 0) /* writing, must allocate blocks */
 #define IOMAP_ZERO		(1 << 1) /* zeroing operation, may skip holes */
 #define IOMAP_REPORT		(1 << 2) /* report extent status, e.g. FIEMAP */
+#define IOMAP_FAULT		(1 << 3) /* mapping for page fault */
 
 struct iomap_ops {
 	/*

include/uapi/linux/fs.h

···
 /* Policy provided via an ioctl on the topmost directory */
 #define FS_KEY_DESCRIPTOR_SIZE	8
 
+#define FS_POLICY_FLAGS_PAD_4		0x00
+#define FS_POLICY_FLAGS_PAD_8		0x01
+#define FS_POLICY_FLAGS_PAD_16		0x02
+#define FS_POLICY_FLAGS_PAD_32		0x03
+#define FS_POLICY_FLAGS_PAD_MASK	0x03
+#define FS_POLICY_FLAGS_VALID		0x03
+
+/* Encryption algorithms */
+#define FS_ENCRYPTION_MODE_INVALID		0
+#define FS_ENCRYPTION_MODE_AES_256_XTS		1
+#define FS_ENCRYPTION_MODE_AES_256_GCM		2
+#define FS_ENCRYPTION_MODE_AES_256_CBC		3
+#define FS_ENCRYPTION_MODE_AES_256_CTS		4
+
 struct fscrypt_policy {
 	__u8 version;
 	__u8 contents_encryption_mode;

mm/filemap.c

···
 		} else {
 			/* DAX can replace empty locked entry with a hole */
 			WARN_ON_ONCE(p !=
-				(void *)(RADIX_TREE_EXCEPTIONAL_ENTRY |
-					 RADIX_DAX_ENTRY_LOCK));
+				dax_radix_locked_entry(0, RADIX_DAX_EMPTY));
 			/* Wakeup waiters for exceptional entry lock */
-			dax_wake_mapping_entry_waiter(mapping, page->index,
+			dax_wake_mapping_entry_waiter(mapping, page->index, p,
 						      false);
 		}
 	}