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

Pull ext4 updates from Ted Ts'o:
 "A very large number of cleanups and bug fixes --- in particular for
  the ext4 encryption patches, which is a new feature added in the last
  merge window.  Also fix a number of long-standing xfstest failures.
  (Quota writes failing due to ENOSPC, a race between truncate and
  writepage in data=journalled mode that was causing generic/068 to
  fail, and other corner cases.)

  Also add support for FALLOC_FL_INSERT_RANGE, and improve jbd2
  performance eliminating locking when a buffer is modified more than
  once during a transaction (which is very common for allocation
  bitmaps, for example), in which case the state of the journalled
  buffer head doesn't need to change"

[ I renamed "ext4_follow_link()" to "ext4_encrypted_follow_link()" in
  the merge resolution, to make it clear that that function is _only_
  used for encrypted symlinks.  The function doesn't actually work for
  non-encrypted symlinks at all, and they use the generic helpers
                                         - Linus ]

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (52 commits)
  ext4: set lazytime on remount if MS_LAZYTIME is set by mount
  ext4: only call ext4_truncate when size <= isize
  ext4: make online defrag error reporting consistent
  ext4: minor cleanup of ext4_da_reserve_space()
  ext4: don't retry file block mapping on bigalloc fs with non-extent file
  ext4: prevent ext4_quota_write() from failing due to ENOSPC
  ext4: call sync_blockdev() before invalidate_bdev() in put_super()
  jbd2: speedup jbd2_journal_dirty_metadata()
  jbd2: get rid of open coded allocation retry loop
  ext4: improve warning directory handling messages
  jbd2: fix ocfs2 corrupt when updating journal superblock fails
  ext4: mballoc: avoid 20-argument function call
  ext4: wait for existing dio workers in ext4_alloc_file_blocks()
  ext4: recalculate journal credits as inode depth changes
  jbd2: use GFP_NOFS in jbd2_cleanup_journal_tail()
  ext4: use swap() in mext_page_double_lock()
  ext4: use swap() in memswap()
  ext4: fix race between truncate and __ext4_journalled_writepage()
  ext4 crypto: fail the mount if blocksize != pagesize
  ext4: Add support FALLOC_FL_INSERT_RANGE for fallocate
  ...

23 files changed, 1227 insertions, 1195 deletions

diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index 024f2284d3f6..bf8bc8aba471 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -72,6 +72,7 @@ config EXT4_ENCRYPTION
 	select CRYPTO_ECB
 	select CRYPTO_XTS
 	select CRYPTO_CTS
+	select CRYPTO_CTR
 	select CRYPTO_SHA256
 	select KEYS
 	select ENCRYPTED_KEYS
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 955bf49a7945..cd6ea29be645 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -369,7 +369,7 @@ static void ext4_validate_block_bitmap(struct super_block *sb,
 	struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
-	if (buffer_verified(bh))
+	if (buffer_verified(bh) || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
 		return;
 
 	ext4_lock_group(sb, block_group);
@@ -446,7 +446,7 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
 		unlock_buffer(bh);
 		if (err)
 			ext4_error(sb, "Checksum bad for grp %u", block_group);
-		return bh;
+		goto verify;
 	}
 	ext4_unlock_group(sb, block_group);
 	if (buffer_uptodate(bh)) {
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index 8ff15273ab0c..45731558138c 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -55,6 +55,9 @@ static mempool_t *ext4_bounce_page_pool;
 static LIST_HEAD(ext4_free_crypto_ctxs);
 static DEFINE_SPINLOCK(ext4_crypto_ctx_lock);
 
+static struct kmem_cache *ext4_crypto_ctx_cachep;
+struct kmem_cache *ext4_crypt_info_cachep;
+
 /**
  * ext4_release_crypto_ctx() - Releases an encryption context
  * @ctx: The encryption context to release.
@@ -68,18 +71,12 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx)
 {
 	unsigned long flags;
 
-	if (ctx->bounce_page) {
-		if (ctx->flags & EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL)
-			__free_page(ctx->bounce_page);
-		else
-			mempool_free(ctx->bounce_page, ext4_bounce_page_pool);
-		ctx->bounce_page = NULL;
-	}
-	ctx->control_page = NULL;
+	if (ctx->flags & EXT4_WRITE_PATH_FL && ctx->w.bounce_page)
+		mempool_free(ctx->w.bounce_page, ext4_bounce_page_pool);
+	ctx->w.bounce_page = NULL;
+	ctx->w.control_page = NULL;
 	if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) {
-		if (ctx->tfm)
-			crypto_free_tfm(ctx->tfm);
-		kfree(ctx);
+		kmem_cache_free(ext4_crypto_ctx_cachep, ctx);
 	} else {
 		spin_lock_irqsave(&ext4_crypto_ctx_lock, flags);
 		list_add(&ctx->free_list, &ext4_free_crypto_ctxs);
@@ -88,23 +85,6 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx)
 }
 
 /**
- * ext4_alloc_and_init_crypto_ctx() - Allocates and inits an encryption context
- * @mask: The allocation mask.
- *
- * Return: An allocated and initialized encryption context on success. An error
- * value or NULL otherwise.
- */
-static struct ext4_crypto_ctx *ext4_alloc_and_init_crypto_ctx(gfp_t mask)
-{
-	struct ext4_crypto_ctx *ctx = kzalloc(sizeof(struct ext4_crypto_ctx),
-					      mask);
-
-	if (!ctx)
-		return ERR_PTR(-ENOMEM);
-	return ctx;
-}
-
-/**
  * ext4_get_crypto_ctx() - Gets an encryption context
  * @inode:       The inode for which we are doing the crypto
  *
@@ -118,10 +98,10 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
 	struct ext4_crypto_ctx *ctx = NULL;
 	int res = 0;
 	unsigned long flags;
-	struct ext4_encryption_key *key = &EXT4_I(inode)->i_encryption_key;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
 
-	if (!ext4_read_workqueue)
-		ext4_init_crypto();
+	if (ci == NULL)
+		return ERR_PTR(-ENOKEY);
 
 	/*
 	 * We first try getting the ctx from a free list because in
@@ -140,50 +120,16 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
 		list_del(&ctx->free_list);
 	spin_unlock_irqrestore(&ext4_crypto_ctx_lock, flags);
 	if (!ctx) {
-		ctx = ext4_alloc_and_init_crypto_ctx(GFP_NOFS);
-		if (IS_ERR(ctx)) {
-			res = PTR_ERR(ctx);
+		ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS);
+		if (!ctx) {
+			res = -ENOMEM;
 			goto out;
 		}
 		ctx->flags |= EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL;
 	} else {
 		ctx->flags &= ~EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL;
 	}
-
-	/* Allocate a new Crypto API context if we don't already have
-	 * one or if it isn't the right mode. */
-	BUG_ON(key->mode == EXT4_ENCRYPTION_MODE_INVALID);
-	if (ctx->tfm && (ctx->mode != key->mode)) {
-		crypto_free_tfm(ctx->tfm);
-		ctx->tfm = NULL;
-		ctx->mode = EXT4_ENCRYPTION_MODE_INVALID;
-	}
-	if (!ctx->tfm) {
-		switch (key->mode) {
-		case EXT4_ENCRYPTION_MODE_AES_256_XTS:
-			ctx->tfm = crypto_ablkcipher_tfm(
-				crypto_alloc_ablkcipher("xts(aes)", 0, 0));
-			break;
-		case EXT4_ENCRYPTION_MODE_AES_256_GCM:
-			/* TODO(mhalcrow): AEAD w/ gcm(aes);
-			 * crypto_aead_setauthsize() */
-			ctx->tfm = ERR_PTR(-ENOTSUPP);
-			break;
-		default:
-			BUG();
-		}
-		if (IS_ERR_OR_NULL(ctx->tfm)) {
-			res = PTR_ERR(ctx->tfm);
-			ctx->tfm = NULL;
-			goto out;
-		}
-		ctx->mode = key->mode;
-	}
-	BUG_ON(key->size != ext4_encryption_key_size(key->mode));
-
-	/* There shouldn't be a bounce page attached to the crypto
-	 * context at this point. */
-	BUG_ON(ctx->bounce_page);
+	ctx->flags &= ~EXT4_WRITE_PATH_FL;
 
 out:
 	if (res) {
@@ -204,20 +150,8 @@ void ext4_exit_crypto(void)
 {
 	struct ext4_crypto_ctx *pos, *n;
 
-	list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list) {
-		if (pos->bounce_page) {
-			if (pos->flags &
-			    EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL) {
-				__free_page(pos->bounce_page);
-			} else {
-				mempool_free(pos->bounce_page,
-					     ext4_bounce_page_pool);
-			}
-		}
-		if (pos->tfm)
-			crypto_free_tfm(pos->tfm);
-		kfree(pos);
-	}
+	list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list)
+		kmem_cache_free(ext4_crypto_ctx_cachep, pos);
 	INIT_LIST_HEAD(&ext4_free_crypto_ctxs);
 	if (ext4_bounce_page_pool)
 		mempool_destroy(ext4_bounce_page_pool);
@@ -225,6 +159,12 @@ void ext4_exit_crypto(void)
 	if (ext4_read_workqueue)
 		destroy_workqueue(ext4_read_workqueue);
 	ext4_read_workqueue = NULL;
+	if (ext4_crypto_ctx_cachep)
+		kmem_cache_destroy(ext4_crypto_ctx_cachep);
+	ext4_crypto_ctx_cachep = NULL;
+	if (ext4_crypt_info_cachep)
+		kmem_cache_destroy(ext4_crypt_info_cachep);
+	ext4_crypt_info_cachep = NULL;
 }
 
 /**
@@ -237,23 +177,31 @@ void ext4_exit_crypto(void)
  */
 int ext4_init_crypto(void)
 {
-	int i, res;
+	int i, res = -ENOMEM;
 
 	mutex_lock(&crypto_init);
 	if (ext4_read_workqueue)
 		goto already_initialized;
 	ext4_read_workqueue = alloc_workqueue("ext4_crypto", WQ_HIGHPRI, 0);
-	if (!ext4_read_workqueue) {
-		res = -ENOMEM;
+	if (!ext4_read_workqueue)
+		goto fail;
+
+	ext4_crypto_ctx_cachep = KMEM_CACHE(ext4_crypto_ctx,
+					    SLAB_RECLAIM_ACCOUNT);
+	if (!ext4_crypto_ctx_cachep)
+		goto fail;
+
+	ext4_crypt_info_cachep = KMEM_CACHE(ext4_crypt_info,
+					    SLAB_RECLAIM_ACCOUNT);
+	if (!ext4_crypt_info_cachep)
 		goto fail;
-	}
 
 	for (i = 0; i < num_prealloc_crypto_ctxs; i++) {
 		struct ext4_crypto_ctx *ctx;
 
-		ctx = ext4_alloc_and_init_crypto_ctx(GFP_KERNEL);
-		if (IS_ERR(ctx)) {
-			res = PTR_ERR(ctx);
+		ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS);
+		if (!ctx) {
+			res = -ENOMEM;
 			goto fail;
 		}
 		list_add(&ctx->free_list, &ext4_free_crypto_ctxs);
@@ -317,32 +265,11 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
 	struct ablkcipher_request *req = NULL;
 	DECLARE_EXT4_COMPLETION_RESULT(ecr);
 	struct scatterlist dst, src;
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	struct crypto_ablkcipher *atfm = __crypto_ablkcipher_cast(ctx->tfm);
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+	struct crypto_ablkcipher *tfm = ci->ci_ctfm;
 	int res = 0;
 
-	BUG_ON(!ctx->tfm);
-	BUG_ON(ctx->mode != ei->i_encryption_key.mode);
-
-	if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) {
-		printk_ratelimited(KERN_ERR
-				   "%s: unsupported crypto algorithm: %d\n",
-				   __func__, ctx->mode);
-		return -ENOTSUPP;
-	}
-
-	crypto_ablkcipher_clear_flags(atfm, ~0);
-	crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
-
-	res = crypto_ablkcipher_setkey(atfm, ei->i_encryption_key.raw,
-				       ei->i_encryption_key.size);
-	if (res) {
-		printk_ratelimited(KERN_ERR
-				   "%s: crypto_ablkcipher_setkey() failed\n",
-				   __func__);
-		return res;
-	}
-	req = ablkcipher_request_alloc(atfm, GFP_NOFS);
+	req = ablkcipher_request_alloc(tfm, GFP_NOFS);
 	if (!req) {
 		printk_ratelimited(KERN_ERR
 				   "%s: crypto_request_alloc() failed\n",
@@ -384,6 +311,15 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
 	return 0;
 }
 
+static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx)
+{
+	ctx->w.bounce_page = mempool_alloc(ext4_bounce_page_pool, GFP_NOWAIT);
+	if (ctx->w.bounce_page == NULL)
+		return ERR_PTR(-ENOMEM);
+	ctx->flags |= EXT4_WRITE_PATH_FL;
+	return ctx->w.bounce_page;
+}
+
 /**
  * ext4_encrypt() - Encrypts a page
  * @inode:          The inode for which the encryption should take place
@@ -413,27 +349,17 @@ struct page *ext4_encrypt(struct inode *inode,
 		return (struct page *) ctx;
 
 	/* The encryption operation will require a bounce page. */
-	ciphertext_page = alloc_page(GFP_NOFS);
-	if (!ciphertext_page) {
-		/* This is a potential bottleneck, but at least we'll have
-		 * forward progress. */
-		ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-						 GFP_NOFS);
-		if (WARN_ON_ONCE(!ciphertext_page)) {
-			ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-							 GFP_NOFS | __GFP_WAIT);
-		}
-		ctx->flags &= ~EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
-	} else {
-		ctx->flags |= EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
-	}
-	ctx->bounce_page = ciphertext_page;
-	ctx->control_page = plaintext_page;
+	ciphertext_page = alloc_bounce_page(ctx);
+	if (IS_ERR(ciphertext_page))
+		goto errout;
+	ctx->w.control_page = plaintext_page;
 	err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, plaintext_page->index,
 			       plaintext_page, ciphertext_page);
 	if (err) {
+		ciphertext_page = ERR_PTR(err);
+	errout:
 		ext4_release_crypto_ctx(ctx);
-		return ERR_PTR(err);
+		return ciphertext_page;
 	}
 	SetPagePrivate(ciphertext_page);
 	set_page_private(ciphertext_page, (unsigned long)ctx);
@@ -470,8 +396,8 @@ int ext4_decrypt_one(struct inode *inode, struct page *page)
 
 	struct ext4_crypto_ctx *ctx = ext4_get_crypto_ctx(inode);
 
-	if (!ctx)
-		return -ENOMEM;
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
 	ret = ext4_decrypt(ctx, page);
 	ext4_release_crypto_ctx(ctx);
 	return ret;
@@ -493,21 +419,11 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex)
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
 
-	ciphertext_page = alloc_page(GFP_NOFS);
-	if (!ciphertext_page) {
-		/* This is a potential bottleneck, but at least we'll have
-		 * forward progress. */
-		ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-						 GFP_NOFS);
-		if (WARN_ON_ONCE(!ciphertext_page)) {
-			ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-							 GFP_NOFS | __GFP_WAIT);
-		}
-		ctx->flags &= ~EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
-	} else {
-		ctx->flags |= EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
+	ciphertext_page = alloc_bounce_page(ctx);
+	if (IS_ERR(ciphertext_page)) {
+		err = PTR_ERR(ciphertext_page);
+		goto errout;
 	}
-	ctx->bounce_page = ciphertext_page;
 
 	while (len--) {
 		err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, lblk,
@@ -529,6 +445,7 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex)
 			goto errout;
 		}
 		err = submit_bio_wait(WRITE, bio);
+		bio_put(bio);
 		if (err)
 			goto errout;
 	}
diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
index fded02f72299..7dc4eb55913c 100644
--- a/fs/ext4/crypto_fname.c
+++ b/fs/ext4/crypto_fname.c
@@ -48,6 +48,12 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
 	return (mode == EXT4_ENCRYPTION_MODE_AES_256_CTS);
 }
 
+static unsigned max_name_len(struct inode *inode)
+{
+	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
+		EXT4_NAME_LEN;
+}
+
 /**
  * ext4_fname_encrypt() -
  *
@@ -55,43 +61,52 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
  * ciphertext. Errors are returned as negative numbers.  We trust the caller to
  * allocate sufficient memory to oname string.
  */
-static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
+static int ext4_fname_encrypt(struct inode *inode,
 			      const struct qstr *iname,
 			      struct ext4_str *oname)
 {
 	u32 ciphertext_len;
 	struct ablkcipher_request *req = NULL;
 	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct crypto_ablkcipher *tfm = ctx->ctfm;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+	struct crypto_ablkcipher *tfm = ci->ci_ctfm;
 	int res = 0;
 	char iv[EXT4_CRYPTO_BLOCK_SIZE];
-	struct scatterlist sg[1];
-	int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
-	char *workbuf;
+	struct scatterlist src_sg, dst_sg;
+	int padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
+	char *workbuf, buf[32], *alloc_buf = NULL;
+	unsigned lim = max_name_len(inode);
 
-	if (iname->len <= 0 || iname->len > ctx->lim)
+	if (iname->len <= 0 || iname->len > lim)
 		return -EIO;
 
 	ciphertext_len = (iname->len < EXT4_CRYPTO_BLOCK_SIZE) ?
 		EXT4_CRYPTO_BLOCK_SIZE : iname->len;
 	ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
-	ciphertext_len = (ciphertext_len > ctx->lim)
-			? ctx->lim : ciphertext_len;
+	ciphertext_len = (ciphertext_len > lim)
+			? lim : ciphertext_len;
+
+	if (ciphertext_len <= sizeof(buf)) {
+		workbuf = buf;
+	} else {
+		alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
+		if (!alloc_buf)
+			return -ENOMEM;
+		workbuf = alloc_buf;
+	}
 
 	/* Allocate request */
 	req = ablkcipher_request_alloc(tfm, GFP_NOFS);
 	if (!req) {
 		printk_ratelimited(
 		    KERN_ERR "%s: crypto_request_alloc() failed\n", __func__);
+		kfree(alloc_buf);
 		return -ENOMEM;
 	}
 	ablkcipher_request_set_callback(req,
 		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
 		ext4_dir_crypt_complete, &ecr);
 
-	/* Map the workpage */
-	workbuf = kmap(ctx->workpage);
-
 	/* Copy the input */
 	memcpy(workbuf, iname->name, iname->len);
 	if (iname->len < ciphertext_len)
@@ -101,21 +116,16 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
 	memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
 
 	/* Create encryption request */
-	sg_init_table(sg, 1);
-	sg_set_page(sg, ctx->workpage, PAGE_SIZE, 0);
-	ablkcipher_request_set_crypt(req, sg, sg, ciphertext_len, iv);
+	sg_init_one(&src_sg, workbuf, ciphertext_len);
+	sg_init_one(&dst_sg, oname->name, ciphertext_len);
+	ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
 	res = crypto_ablkcipher_encrypt(req);
 	if (res == -EINPROGRESS || res == -EBUSY) {
 		BUG_ON(req->base.data != &ecr);
 		wait_for_completion(&ecr.completion);
 		res = ecr.res;
 	}
-	if (res >= 0) {
-		/* Copy the result to output */
-		memcpy(oname->name, workbuf, ciphertext_len);
-		res = ciphertext_len;
-	}
-	kunmap(ctx->workpage);
+	kfree(alloc_buf);
 	ablkcipher_request_free(req);
 	if (res < 0) {
 		printk_ratelimited(
@@ -132,20 +142,21 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
  *	Errors are returned as negative numbers.
  *	We trust the caller to allocate sufficient memory to oname string.
  */
-static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
+static int ext4_fname_decrypt(struct inode *inode,
 			      const struct ext4_str *iname,
 			      struct ext4_str *oname)
 {
 	struct ext4_str tmp_in[2], tmp_out[1];
 	struct ablkcipher_request *req = NULL;
 	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct scatterlist sg[1];
-	struct crypto_ablkcipher *tfm = ctx->ctfm;
+	struct scatterlist src_sg, dst_sg;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+	struct crypto_ablkcipher *tfm = ci->ci_ctfm;
 	int res = 0;
 	char iv[EXT4_CRYPTO_BLOCK_SIZE];
-	char *workbuf;
+	unsigned lim = max_name_len(inode);
 
-	if (iname->len <= 0 || iname->len > ctx->lim)
+	if (iname->len <= 0 || iname->len > lim)
 		return -EIO;
 
 	tmp_in[0].name = iname->name;
@@ -163,31 +174,19 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
 		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
 		ext4_dir_crypt_complete, &ecr);
 
-	/* Map the workpage */
-	workbuf = kmap(ctx->workpage);
-
-	/* Copy the input */
-	memcpy(workbuf, iname->name, iname->len);
-
 	/* Initialize IV */
 	memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
 
 	/* Create encryption request */
-	sg_init_table(sg, 1);
-	sg_set_page(sg, ctx->workpage, PAGE_SIZE, 0);
-	ablkcipher_request_set_crypt(req, sg, sg, iname->len, iv);
+	sg_init_one(&src_sg, iname->name, iname->len);
+	sg_init_one(&dst_sg, oname->name, oname->len);
+	ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv);
 	res = crypto_ablkcipher_decrypt(req);
 	if (res == -EINPROGRESS || res == -EBUSY) {
 		BUG_ON(req->base.data != &ecr);
 		wait_for_completion(&ecr.completion);
 		res = ecr.res;
 	}
-	if (res >= 0) {
-		/* Copy the result to output */
-		memcpy(oname->name, workbuf, iname->len);
-		res = iname->len;
-	}
-	kunmap(ctx->workpage);
 	ablkcipher_request_free(req);
 	if (res < 0) {
 		printk_ratelimited(
@@ -254,207 +253,6 @@ static int digest_decode(const char *src, int len, char *dst)
 }
 
 /**
- * ext4_free_fname_crypto_ctx() -
- *
- * Frees up a crypto context.
- */
-void ext4_free_fname_crypto_ctx(struct ext4_fname_crypto_ctx *ctx)
-{
-	if (ctx == NULL || IS_ERR(ctx))
-		return;
-
-	if (ctx->ctfm && !IS_ERR(ctx->ctfm))
-		crypto_free_ablkcipher(ctx->ctfm);
-	if (ctx->htfm && !IS_ERR(ctx->htfm))
-		crypto_free_hash(ctx->htfm);
-	if (ctx->workpage && !IS_ERR(ctx->workpage))
-		__free_page(ctx->workpage);
-	kfree(ctx);
-}
-
-/**
- * ext4_put_fname_crypto_ctx() -
- *
- * Return: The crypto context onto free list. If the free list is above a
- * threshold, completely frees up the context, and returns the memory.
- *
- * TODO: Currently we directly free the crypto context. Eventually we should
- * add code it to return to free list. Such an approach will increase
- * efficiency of directory lookup.
- */
-void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx)
-{
-	if (*ctx == NULL || IS_ERR(*ctx))
-		return;
-	ext4_free_fname_crypto_ctx(*ctx);
-	*ctx = NULL;
-}
-
-/**
- * ext4_search_fname_crypto_ctx() -
- */
-static struct ext4_fname_crypto_ctx *ext4_search_fname_crypto_ctx(
-		const struct ext4_encryption_key *key)
-{
-	return NULL;
-}
-
-/**
- * ext4_alloc_fname_crypto_ctx() -
- */
-struct ext4_fname_crypto_ctx *ext4_alloc_fname_crypto_ctx(
-	const struct ext4_encryption_key *key)
-{
-	struct ext4_fname_crypto_ctx *ctx;
-
-	ctx = kmalloc(sizeof(struct ext4_fname_crypto_ctx), GFP_NOFS);
-	if (ctx == NULL)
-		return ERR_PTR(-ENOMEM);
-	if (key->mode == EXT4_ENCRYPTION_MODE_INVALID) {
-		/* This will automatically set key mode to invalid
-		 * As enum for ENCRYPTION_MODE_INVALID is zero */
-		memset(&ctx->key, 0, sizeof(ctx->key));
-	} else {
-		memcpy(&ctx->key, key, sizeof(struct ext4_encryption_key));
-	}
-	ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == key->mode)
-		? 0 : 1;
-	ctx->ctfm_key_is_ready = 0;
-	ctx->ctfm = NULL;
-	ctx->htfm = NULL;
-	ctx->workpage = NULL;
-	return ctx;
-}
-
-/**
- * ext4_get_fname_crypto_ctx() -
- *
- * Allocates a free crypto context and initializes it to hold
- * the crypto material for the inode.
- *
- * Return: NULL if not encrypted. Error value on error. Valid pointer otherwise.
- */
-struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
-	struct inode *inode, u32 max_ciphertext_len)
-{
-	struct ext4_fname_crypto_ctx *ctx;
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	int res;
-
-	/* Check if the crypto policy is set on the inode */
-	res = ext4_encrypted_inode(inode);
-	if (res == 0)
-		return NULL;
-
-	if (!ext4_has_encryption_key(inode))
-		ext4_generate_encryption_key(inode);
-
-	/* Get a crypto context based on the key.
-	 * A new context is allocated if no context matches the requested key.
-	 */
-	ctx = ext4_search_fname_crypto_ctx(&(ei->i_encryption_key));
-	if (ctx == NULL)
-		ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_encryption_key));
-	if (IS_ERR(ctx))
-		return ctx;
-
-	ctx->flags = ei->i_crypt_policy_flags;
-	if (ctx->has_valid_key) {
-		if (ctx->key.mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
-			printk_once(KERN_WARNING
-				    "ext4: unsupported key mode %d\n",
-				    ctx->key.mode);
-			return ERR_PTR(-ENOKEY);
-		}
-
-		/* As a first cut, we will allocate new tfm in every call.
-		 * later, we will keep the tfm around, in case the key gets
-		 * re-used */
-		if (ctx->ctfm == NULL) {
-			ctx->ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))",
-					0, 0);
-		}
-		if (IS_ERR(ctx->ctfm)) {
-			res = PTR_ERR(ctx->ctfm);
-			printk(
-			    KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
-			    __func__, res);
-			ctx->ctfm = NULL;
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(res);
-		}
-		if (ctx->ctfm == NULL) {
-			printk(
-			    KERN_DEBUG "%s: could not allocate crypto tfm\n",
-			    __func__);
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(-ENOMEM);
-		}
-		if (ctx->workpage == NULL)
-			ctx->workpage = alloc_page(GFP_NOFS);
-		if (IS_ERR(ctx->workpage)) {
-			res = PTR_ERR(ctx->workpage);
-			printk(
-			    KERN_DEBUG "%s: error (%d) allocating work page\n",
-			    __func__, res);
-			ctx->workpage = NULL;
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(res);
-		}
-		if (ctx->workpage == NULL) {
-			printk(
-			    KERN_DEBUG "%s: could not allocate work page\n",
-			    __func__);
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(-ENOMEM);
-		}
-		ctx->lim = max_ciphertext_len;
-		crypto_ablkcipher_clear_flags(ctx->ctfm, ~0);
-		crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctx->ctfm),
-			CRYPTO_TFM_REQ_WEAK_KEY);
-
-		/* If we are lucky, we will get a context that is already
-		 * set up with the right key. Else, we will have to
-		 * set the key */
-		if (!ctx->ctfm_key_is_ready) {
-			/* Since our crypto objectives for filename encryption
-			 * are pretty weak,
-			 * we directly use the inode master key */
-			res = crypto_ablkcipher_setkey(ctx->ctfm,
-					ctx->key.raw, ctx->key.size);
-			if (res) {
-				ext4_put_fname_crypto_ctx(&ctx);
-				return ERR_PTR(-EIO);
-			}
-			ctx->ctfm_key_is_ready = 1;
-		} else {
-			/* In the current implementation, key should never be
-			 * marked "ready" for a context that has just been
-			 * allocated. So we should never reach here */
-			 BUG();
-		}
-	}
-	if (ctx->htfm == NULL)
-		ctx->htfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(ctx->htfm)) {
-		res = PTR_ERR(ctx->htfm);
-		printk(KERN_DEBUG "%s: error (%d) allocating hash tfm\n",
-			__func__, res);
-		ctx->htfm = NULL;
-		ext4_put_fname_crypto_ctx(&ctx);
-		return ERR_PTR(res);
-	}
-	if (ctx->htfm == NULL) {
-		printk(KERN_DEBUG "%s: could not allocate hash tfm\n",
-				__func__);
-		ext4_put_fname_crypto_ctx(&ctx);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	return ctx;
-}
-
-/**
  * ext4_fname_crypto_round_up() -
  *
  * Return: The next multiple of block size
@@ -464,44 +262,29 @@ u32 ext4_fname_crypto_round_up(u32 size, u32 blksize)
 	return ((size+blksize-1)/blksize)*blksize;
 }
 
-/**
- * ext4_fname_crypto_namelen_on_disk() -
- */
-int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
-				      u32 namelen)
+unsigned ext4_fname_encrypted_size(struct inode *inode, u32 ilen)
 {
-	u32 ciphertext_len;
-	int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
-
-	if (ctx == NULL)
-		return -EIO;
-	if (!(ctx->has_valid_key))
-		return -EACCES;
-	ciphertext_len = (namelen < EXT4_CRYPTO_BLOCK_SIZE) ?
-		EXT4_CRYPTO_BLOCK_SIZE : namelen;
-	ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
-	ciphertext_len = (ciphertext_len > ctx->lim)
-			? ctx->lim : ciphertext_len;
-	return (int) ciphertext_len;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+	int padding = 32;
+
+	if (ci)
+		padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
+	if (ilen < EXT4_CRYPTO_BLOCK_SIZE)
+		ilen = EXT4_CRYPTO_BLOCK_SIZE;
+	return ext4_fname_crypto_round_up(ilen, padding);
 }
 
-/**
- * ext4_fname_crypto_alloc_obuff() -
+/*
+ * ext4_fname_crypto_alloc_buffer() -
  *
  * Allocates an output buffer that is sufficient for the crypto operation
  * specified by the context and the direction.
  */
-int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_crypto_alloc_buffer(struct inode *inode,
 				   u32 ilen, struct ext4_str *crypto_str)
 {
-	unsigned int olen;
-	int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
+	unsigned int olen = ext4_fname_encrypted_size(inode, ilen);
 
-	if (!ctx)
-		return -EIO;
-	if (padding < EXT4_CRYPTO_BLOCK_SIZE)
-		padding = EXT4_CRYPTO_BLOCK_SIZE;
-	olen = ext4_fname_crypto_round_up(ilen, padding);
 	crypto_str->len = olen;
 	if (olen < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2)
 		olen = EXT4_FNAME_CRYPTO_DIGEST_SIZE*2;
@@ -529,7 +312,7 @@ void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str)
 /**
  * ext4_fname_disk_to_usr() - converts a filename from disk space to user space
  */
-int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+int _ext4_fname_disk_to_usr(struct inode *inode,
 			    struct dx_hash_info *hinfo,
 			    const struct ext4_str *iname,
 			    struct ext4_str *oname)
@@ -537,8 +320,6 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
 	char buf[24];
 	int ret;
 
-	if (ctx == NULL)
-		return -EIO;
 	if (iname->len < 3) {
 		/*Check for . and .. */
 		if (iname->name[0] == '.' && iname->name[iname->len-1] == '.') {
@@ -548,8 +329,8 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
 			return oname->len;
 		}
 	}
-	if (ctx->has_valid_key)
-		return ext4_fname_decrypt(ctx, iname, oname);
+	if (EXT4_I(inode)->i_crypt_info)
+		return ext4_fname_decrypt(inode, iname, oname);
 
 	if (iname->len <= EXT4_FNAME_CRYPTO_DIGEST_SIZE) {
 		ret = digest_encode(iname->name, iname->len, oname->name);
@@ -568,7 +349,7 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
 	return ret + 1;
 }
 
-int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_disk_to_usr(struct inode *inode,
 			   struct dx_hash_info *hinfo,
 			   const struct ext4_dir_entry_2 *de,
 			   struct ext4_str *oname)
@@ -576,21 +357,20 @@ int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
 	struct ext4_str iname = {.name = (unsigned char *) de->name,
 				 .len = de->name_len };
 
-	return _ext4_fname_disk_to_usr(ctx, hinfo, &iname, oname);
+	return _ext4_fname_disk_to_usr(inode, hinfo, &iname, oname);
 }
 
 
 /**
  * ext4_fname_usr_to_disk() - converts a filename from user space to disk space
  */
-int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_usr_to_disk(struct inode *inode,
 			   const struct qstr *iname,
 			   struct ext4_str *oname)
 {
 	int res;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
 
-	if (ctx == NULL)
-		return -EIO;
 	if (iname->len < 3) {
 		/*Check for . and .. */
 		if (iname->name[0] == '.' &&
@@ -601,8 +381,8 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
 			return oname->len;
 		}
 	}
-	if (ctx->has_valid_key) {
-		res = ext4_fname_encrypt(ctx, iname, oname);