2019-08-16 06:18:34

by Chandan Rajendra

[permalink] [raw]
Subject: [PATCH V4 8/8] fscrypt: remove struct fscrypt_ctx

Commit "fscrypt: remove the 'write' part of struct fscrypt_ctx" reduced
"struct fscrypt_ctx" to be used only for decryption. With "read
callbacks" being integrated into Ext4 and F2FS, we don't use "struct
fscrypt_ctx" anymore. Hence this commit removes the structure and the
associated code.

While at it, this commit also removes definitions of
__fscrypt_decrypt_bio() and fscrypt_decrypt_bio() since we have to now
use the APIs provided by read_callbacks facility.

Signed-off-by: Chandan Rajendra <[email protected]>
---
fs/crypto/bio.c | 43 ------------------
fs/crypto/crypto.c | 89 +------------------------------------
fs/crypto/fscrypt_private.h | 3 --
include/linux/fscrypt.h | 38 ----------------
4 files changed, 2 insertions(+), 171 deletions(-)

diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index b4f47b98ee6d..f65cc3059e5c 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -26,49 +26,6 @@
#include <linux/namei.h>
#include "fscrypt_private.h"

-static void __fscrypt_decrypt_bio(struct bio *bio, bool done)
-{
- struct bio_vec *bv;
- int i;
- struct bvec_iter_all iter_all;
-
- bio_for_each_segment_all(bv, bio, i, iter_all) {
- struct page *page = bv->bv_page;
- int ret = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
- 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)
{
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index dcf630d7e446..2e5245f5639f 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -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);
@@ -399,11 +335,6 @@ const struct dentry_operations fscrypt_d_ops = {

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;
}
@@ -419,7 +350,7 @@ static void fscrypt_destroy(void)
*/
int fscrypt_initialize(unsigned int cop_flags)
{
- int i, res = -ENOMEM;
+ int res = -ENOMEM;

/* No need to allocate a bounce page pool if this FS won't use it. */
if (cop_flags & FS_CFLG_OWN_PAGES)
@@ -429,15 +360,6 @@ int fscrypt_initialize(unsigned int cop_flags)
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);
- }
-
fscrypt_bounce_page_pool =
mempool_create_page_pool(num_prealloc_crypto_pages, 0);
if (!fscrypt_bounce_page_pool)
@@ -492,18 +414,12 @@ 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;

return 0;

-fail_free_ctx:
- kmem_cache_destroy(fscrypt_ctx_cachep);
fail_free_queue:
destroy_workqueue(fscrypt_read_workqueue);
fail:
@@ -520,7 +436,6 @@ static void __exit fscrypt_exit(void)

if (fscrypt_read_workqueue)
destroy_workqueue(fscrypt_read_workqueue);
- kmem_cache_destroy(fscrypt_ctx_cachep);
kmem_cache_destroy(fscrypt_info_cachep);

fscrypt_essiv_cleanup();
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 8565536feb2b..702403dc7614 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -93,9 +93,6 @@ typedef enum {
FS_ENCRYPT,
} fscrypt_direction_t;

-#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
-#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
-
static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
u32 filenames_mode)
{
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 4d6528351f25..ce3b15fd9fba 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -19,7 +19,6 @@

#define FS_CRYPTO_BLOCK_SIZE 16

-struct fscrypt_ctx;
struct fscrypt_info;

struct fscrypt_str {
@@ -63,18 +62,6 @@ 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() */
@@ -101,8 +88,6 @@ 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,
@@ -232,9 +217,6 @@ 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);

@@ -279,16 +261,6 @@ 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,
@@ -425,16 +397,6 @@ static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
}

-/* bio.c */
-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)
{
--
2.19.1