Commit 1565bdad authored by Eric Biggers's avatar Eric Biggers
Browse files

fscrypt: remove struct fscrypt_ctx 



Now that ext4 and f2fs implement their own post-read workflow that
supports both fscrypt and fsverity, the fscrypt-only workflow based
around struct fscrypt_ctx is no longer used.  So remove the unused code.

This is based on a patch from Chandan Rajendra's "Consolidate FS read
I/O callbacks code" patchset, but rebased onto the latest kernel, folded
__fscrypt_decrypt_bio() into fscrypt_decrypt_bio(), cleaned up
fscrypt_initialize(), and updated the commit message.

Originally-from: Chandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
parent 4006d799

fs/crypto/bio.c

+1 −28
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ 
#include <linux/namei.h>

#include "fscrypt_private.h"



static void __fscrypt_decrypt_bio(struct bio *bio, bool done)

void fscrypt_decrypt_bio(struct bio *bio)

{

	struct bio_vec *bv;

	struct bvec_iter_all iter_all;
@@ -37,37 +37,10 @@ static void __fscrypt_decrypt_bio(struct bio *bio, bool done) 
							   bv->bv_offset);

		if (ret)

			SetPageError(page);

		else if (done)

			SetPageUptodate(page);

		if (done)

			unlock_page(page);

	}

}



void fscrypt_decrypt_bio(struct bio *bio)

{

	__fscrypt_decrypt_bio(bio, false);

}

EXPORT_SYMBOL(fscrypt_decrypt_bio);



static void completion_pages(struct work_struct *work)

{

	struct fscrypt_ctx *ctx = container_of(work, struct fscrypt_ctx, work);

	struct bio *bio = ctx->bio;



	__fscrypt_decrypt_bio(bio, true);

	fscrypt_release_ctx(ctx);

	bio_put(bio);

}



void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx, struct bio *bio)

{

	INIT_WORK(&ctx->work, completion_pages);

	ctx->bio = bio;

	fscrypt_enqueue_decrypt_work(&ctx->work);

}

EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio);



int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,

				sector_t pblk, unsigned int len)

{

fs/crypto/crypto.c

+9 −101
Original line number Diff line number Diff line
@@ -31,24 +31,16 @@ 
#include "fscrypt_private.h"



static unsigned int num_prealloc_crypto_pages = 32;

static unsigned int num_prealloc_crypto_ctxs = 128;



module_param(num_prealloc_crypto_pages, uint, 0444);

MODULE_PARM_DESC(num_prealloc_crypto_pages,

		"Number of crypto pages to preallocate");

module_param(num_prealloc_crypto_ctxs, uint, 0444);

MODULE_PARM_DESC(num_prealloc_crypto_ctxs,

		"Number of crypto contexts to preallocate");



static mempool_t *fscrypt_bounce_page_pool = NULL;



static LIST_HEAD(fscrypt_free_ctxs);

static DEFINE_SPINLOCK(fscrypt_ctx_lock);



static struct workqueue_struct *fscrypt_read_workqueue;

static DEFINE_MUTEX(fscrypt_init_mutex);



static struct kmem_cache *fscrypt_ctx_cachep;

struct kmem_cache *fscrypt_info_cachep;



void fscrypt_enqueue_decrypt_work(struct work_struct *work)
@@ -57,62 +49,6 @@ void fscrypt_enqueue_decrypt_work(struct work_struct *work) 
}

EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work);



/**

 * fscrypt_release_ctx() - Release a decryption context

 * @ctx: The decryption context to release.

 *

 * If the decryption context was allocated from the pre-allocated pool, return

 * it to that pool.  Else, free it.

 */

void fscrypt_release_ctx(struct fscrypt_ctx *ctx)

{

	unsigned long flags;



	if (ctx->flags & FS_CTX_REQUIRES_FREE_ENCRYPT_FL) {

		kmem_cache_free(fscrypt_ctx_cachep, ctx);

	} else {

		spin_lock_irqsave(&fscrypt_ctx_lock, flags);

		list_add(&ctx->free_list, &fscrypt_free_ctxs);

		spin_unlock_irqrestore(&fscrypt_ctx_lock, flags);

	}

}

EXPORT_SYMBOL(fscrypt_release_ctx);



/**

 * fscrypt_get_ctx() - Get a decryption context

 * @gfp_flags:   The gfp flag for memory allocation

 *

 * Allocate and initialize a decryption context.

 *

 * Return: A new decryption context on success; an ERR_PTR() otherwise.

 */

struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags)

{

	struct fscrypt_ctx *ctx;

	unsigned long flags;



	/*

	 * First try getting a ctx from the free list so that we don't have to

	 * call into the slab allocator.

	 */

	spin_lock_irqsave(&fscrypt_ctx_lock, flags);

	ctx = list_first_entry_or_null(&fscrypt_free_ctxs,

					struct fscrypt_ctx, free_list);

	if (ctx)

		list_del(&ctx->free_list);

	spin_unlock_irqrestore(&fscrypt_ctx_lock, flags);

	if (!ctx) {

		ctx = kmem_cache_zalloc(fscrypt_ctx_cachep, gfp_flags);

		if (!ctx)

			return ERR_PTR(-ENOMEM);

		ctx->flags |= FS_CTX_REQUIRES_FREE_ENCRYPT_FL;

	} else {

		ctx->flags &= ~FS_CTX_REQUIRES_FREE_ENCRYPT_FL;

	}

	return ctx;

}

EXPORT_SYMBOL(fscrypt_get_ctx);



struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags)

{

	return mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
@@ -392,17 +328,6 @@ const struct dentry_operations fscrypt_d_ops = { 
	.d_revalidate = fscrypt_d_revalidate,

};



static void fscrypt_destroy(void)

{

	struct fscrypt_ctx *pos, *n;



	list_for_each_entry_safe(pos, n, &fscrypt_free_ctxs, free_list)

		kmem_cache_free(fscrypt_ctx_cachep, pos);

	INIT_LIST_HEAD(&fscrypt_free_ctxs);

	mempool_destroy(fscrypt_bounce_page_pool);

	fscrypt_bounce_page_pool = NULL;

}



/**

 * fscrypt_initialize() - allocate major buffers for fs encryption.

 * @cop_flags:  fscrypt operations flags
@@ -410,11 +335,11 @@ static void fscrypt_destroy(void) 
 * 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.

 * Return: 0 on success; -errno on failure

 */

int fscrypt_initialize(unsigned int cop_flags)

{

	int i, res = -ENOMEM;

	int err = 0;



	/* No need to allocate a bounce page pool if this FS won't use it. */

	if (cop_flags & FS_CFLG_OWN_PAGES)
@@ -422,29 +347,18 @@ int fscrypt_initialize(unsigned int cop_flags) 


	mutex_lock(&fscrypt_init_mutex);

	if (fscrypt_bounce_page_pool)

		goto already_initialized;



	for (i = 0; i < num_prealloc_crypto_ctxs; i++) {

		struct fscrypt_ctx *ctx;



		ctx = kmem_cache_zalloc(fscrypt_ctx_cachep, GFP_NOFS);

		if (!ctx)

			goto fail;

		list_add(&ctx->free_list, &fscrypt_free_ctxs);

	}

		goto out_unlock;



	err = -ENOMEM;

	fscrypt_bounce_page_pool =

		mempool_create_page_pool(num_prealloc_crypto_pages, 0);

	if (!fscrypt_bounce_page_pool)

		goto fail;

		goto out_unlock;



already_initialized:

	err = 0;

out_unlock:

	mutex_unlock(&fscrypt_init_mutex);

	return 0;

fail:

	fscrypt_destroy();

	mutex_unlock(&fscrypt_init_mutex);

	return res;

	return err;

}



void fscrypt_msg(const struct inode *inode, const char *level,
@@ -490,13 +404,9 @@ static int __init fscrypt_init(void) 
	if (!fscrypt_read_workqueue)

		goto fail;



	fscrypt_ctx_cachep = KMEM_CACHE(fscrypt_ctx, SLAB_RECLAIM_ACCOUNT);

	if (!fscrypt_ctx_cachep)

		goto fail_free_queue;



	fscrypt_info_cachep = KMEM_CACHE(fscrypt_info, SLAB_RECLAIM_ACCOUNT);

	if (!fscrypt_info_cachep)

		goto fail_free_ctx;

		goto fail_free_queue;



	err = fscrypt_init_keyring();

	if (err)
@@ -506,8 +416,6 @@ static int __init fscrypt_init(void) 


fail_free_info:

	kmem_cache_destroy(fscrypt_info_cachep);

fail_free_ctx:

	kmem_cache_destroy(fscrypt_ctx_cachep);

fail_free_queue:

	destroy_workqueue(fscrypt_read_workqueue);

fail:

fs/crypto/fscrypt_private.h

+0 −2
Original line number Diff line number Diff line
@@ -203,8 +203,6 @@ typedef enum { 
	FS_ENCRYPT,

} fscrypt_direction_t;



#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL		0x00000001



static inline bool fscrypt_valid_enc_modes(u32 contents_mode,

					   u32 filenames_mode)

{

include/linux/fscrypt.h

+0 −32
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ 


#define FS_CRYPTO_BLOCK_SIZE		16



struct fscrypt_ctx;

struct fscrypt_info;



struct fscrypt_str {
@@ -64,18 +63,6 @@ struct fscrypt_operations { 
	unsigned int max_namelen;

};



/* Decryption work */

struct fscrypt_ctx {

	union {

		struct {

			struct bio *bio;

			struct work_struct work;

		};

		struct list_head free_list;	/* Free list */

	};

	u8 flags;				/* Flags */

};



static inline bool fscrypt_has_encryption_key(const struct inode *inode)

{

	/* pairs with cmpxchg_release() in fscrypt_get_encryption_info() */
@@ -102,8 +89,6 @@ static inline void fscrypt_handle_d_move(struct dentry *dentry) 


/* crypto.c */

extern void fscrypt_enqueue_decrypt_work(struct work_struct *);

extern struct fscrypt_ctx *fscrypt_get_ctx(gfp_t);

extern void fscrypt_release_ctx(struct fscrypt_ctx *);



extern struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,

						     unsigned int len,
@@ -244,8 +229,6 @@ static inline bool fscrypt_match_name(const struct fscrypt_name *fname, 


/* bio.c */

extern void fscrypt_decrypt_bio(struct bio *);

extern void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,

					struct bio *bio);

extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,

				 unsigned int);
@@ -295,16 +278,6 @@ static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work) 
{

}



static inline struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags)

{

	return ERR_PTR(-EOPNOTSUPP);

}



static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)

{

	return;

}



static inline struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,

							    unsigned int len,

							    unsigned int offs,
@@ -484,11 +457,6 @@ static inline void fscrypt_decrypt_bio(struct bio *bio) 
{

}



static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,

					       struct bio *bio)

{

}



static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,

					sector_t pblk, unsigned int len)

{

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