On 2019/4/28 12:31, Chandan Rajendra wrote:
> The "read callbacks" code is used by both Ext4 and F2FS. Hence to
> remove duplicity, this commit moves the code into
> include/linux/read_callbacks.h and fs/read_callbacks.c.
>
> The corresponding decrypt and verity "work" functions have been moved
> inside fscrypt and fsverity sources. With these in place, the read
> callbacks code now has to just invoke enqueue functions provided by
> fscrypt and fsverity.
>
> Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxx>
> ---
> fs/Kconfig | 4 +
> fs/Makefile | 4 +
> fs/crypto/Kconfig | 1 +
> fs/crypto/bio.c | 23 ++---
> fs/crypto/crypto.c | 17 +--
> fs/crypto/fscrypt_private.h | 3 +
> fs/ext4/ext4.h | 2 -
> fs/ext4/readpage.c | 183 +++++----------------------------
> fs/ext4/super.c | 9 +-
> fs/f2fs/data.c | 148 ++++----------------------
> fs/f2fs/super.c | 9 +-
> fs/read_callbacks.c | 136 ++++++++++++++++++++++++
> fs/verity/Kconfig | 1 +
> fs/verity/verify.c | 12 +++
> include/linux/fscrypt.h | 20 +---
> include/linux/read_callbacks.h | 21 ++++
> 16 files changed, 251 insertions(+), 342 deletions(-)
> create mode 100644 fs/read_callbacks.c
> create mode 100644 include/linux/read_callbacks.h
>
> diff --git a/fs/Kconfig b/fs/Kconfig
> index 97f9eb8df713..03084f2dbeaf 100644
> --- a/fs/Kconfig
> +++ b/fs/Kconfig
> @@ -308,6 +308,10 @@ config NFS_COMMON
> depends on NFSD || NFS_FS || LOCKD
> default y
>
> +config FS_READ_CALLBACKS
> + bool
> + default n
> +
> source "net/sunrpc/Kconfig"
> source "fs/ceph/Kconfig"
> source "fs/cifs/Kconfig"
> diff --git a/fs/Makefile b/fs/Makefile
> index 9dd2186e74b5..e0c0fce8cf40 100644
> --- a/fs/Makefile
> +++ b/fs/Makefile
> @@ -21,6 +21,10 @@ else
> obj-y += no-block.o
> endif
>
> +ifeq ($(CONFIG_FS_READ_CALLBACKS),y)
> +obj-y += read_callbacks.o
> +endif
> +
> obj-$(CONFIG_PROC_FS) += proc_namespace.o
>
> obj-y += notify/
> diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig
> index f0de238000c0..163c328bcbd4 100644
> --- a/fs/crypto/Kconfig
> +++ b/fs/crypto/Kconfig
> @@ -8,6 +8,7 @@ config FS_ENCRYPTION
> select CRYPTO_CTS
> select CRYPTO_SHA256
> select KEYS
> + select FS_READ_CALLBACKS
> help
> Enable encryption of files and directories. This
> feature is similar to ecryptfs, but it is more memory
> diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
> index 5759bcd018cd..27f5618174f2 100644
> --- a/fs/crypto/bio.c
> +++ b/fs/crypto/bio.c
> @@ -24,6 +24,8 @@
> #include <linux/module.h>
> #include <linux/bio.h>
> #include <linux/namei.h>
> +#include <linux/read_callbacks.h>
> +
> #include "fscrypt_private.h"
>
> static void __fscrypt_decrypt_bio(struct bio *bio, bool done)
> @@ -54,24 +56,15 @@ void fscrypt_decrypt_bio(struct bio *bio)
> }
> EXPORT_SYMBOL(fscrypt_decrypt_bio);
>
> -static void completion_pages(struct work_struct *work)
> +void fscrypt_decrypt_work(struct work_struct *work)
> {
> - struct fscrypt_ctx *ctx =
> - container_of(work, struct fscrypt_ctx, r.work);
> - struct bio *bio = ctx->r.bio;
> + struct read_callbacks_ctx *ctx =
> + container_of(work, struct read_callbacks_ctx, work);
>
> - __fscrypt_decrypt_bio(bio, true);
> - fscrypt_release_ctx(ctx);
> - bio_put(bio);
> -}
> + fscrypt_decrypt_bio(ctx->bio);
>
> -void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx, struct bio *bio)
> -{
> - INIT_WORK(&ctx->r.work, completion_pages);
> - ctx->r.bio = bio;
> - fscrypt_enqueue_decrypt_work(&ctx->r.work);
> + read_callbacks(ctx);
> }
> -EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio);
>
> void fscrypt_pullback_bio_page(struct page **page, bool restore)
> {
> @@ -87,7 +80,7 @@ void fscrypt_pullback_bio_page(struct page **page, bool restore)
> ctx = (struct fscrypt_ctx *)page_private(bounce_page);
>
> /* restore control page */
> - *page = ctx->w.control_page;
> + *page = ctx->control_page;
>
> if (restore)
> fscrypt_restore_control_page(bounce_page);
> diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
> index 3fc84bf2b1e5..ffa9302a7351 100644
> --- a/fs/crypto/crypto.c
> +++ b/fs/crypto/crypto.c
> @@ -53,6 +53,7 @@ struct kmem_cache *fscrypt_info_cachep;
>
> void fscrypt_enqueue_decrypt_work(struct work_struct *work)
> {
> + INIT_WORK(work, fscrypt_decrypt_work);
> queue_work(fscrypt_read_workqueue, work);
> }
> EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work);
> @@ -70,11 +71,11 @@ void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
> {
> unsigned long flags;
>
> - 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;
> + if (ctx->flags & FS_CTX_HAS_BOUNCE_BUFFER_FL && ctx->bounce_page) {
> + mempool_free(ctx->bounce_page, fscrypt_bounce_page_pool);
> + ctx->bounce_page = NULL;
> }
> - ctx->w.control_page = NULL;
> + ctx->control_page = NULL;
> if (ctx->flags & FS_CTX_REQUIRES_FREE_ENCRYPT_FL) {
> kmem_cache_free(fscrypt_ctx_cachep, ctx);
> } else {
> @@ -194,11 +195,11 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
> struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
> gfp_t gfp_flags)
> {
> - ctx->w.bounce_page = mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
> - if (ctx->w.bounce_page == NULL)
> + ctx->bounce_page = mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
> + if (ctx->bounce_page == NULL)
> return ERR_PTR(-ENOMEM);
> ctx->flags |= FS_CTX_HAS_BOUNCE_BUFFER_FL;
> - return ctx->w.bounce_page;
> + return ctx->bounce_page;
> }
>
> /**
> @@ -267,7 +268,7 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
> if (IS_ERR(ciphertext_page))
> goto errout;
>
> - ctx->w.control_page = page;
> + ctx->control_page = page;
> err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk_num,
> page, ciphertext_page, len, offs,
> gfp_flags);
> diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
> index 7da276159593..412a3bcf9efd 100644
> --- a/fs/crypto/fscrypt_private.h
> +++ b/fs/crypto/fscrypt_private.h
> @@ -114,6 +114,9 @@ static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
> return false;
> }
>
> +/* bio.c */
> +void fscrypt_decrypt_work(struct work_struct *work);
> +
> /* crypto.c */
> extern struct kmem_cache *fscrypt_info_cachep;
> extern int fscrypt_initialize(unsigned int cop_flags);
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index f2b0e628ff7b..23f8568c9b53 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -3127,8 +3127,6 @@ static inline void ext4_set_de_type(struct super_block *sb,
> extern int ext4_mpage_readpages(struct address_space *mapping,
> struct list_head *pages, struct page *page,
> unsigned nr_pages, bool is_readahead);
> -extern int __init ext4_init_post_read_processing(void);
> -extern void ext4_exit_post_read_processing(void);
>
> /* symlink.c */
> extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
> diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
> index 0169e3809da3..e363dededc21 100644
> --- a/fs/ext4/readpage.c
> +++ b/fs/ext4/readpage.c
> @@ -44,14 +44,10 @@
> #include <linux/backing-dev.h>
> #include <linux/pagevec.h>
> #include <linux/cleancache.h>
> +#include <linux/read_callbacks.h>
>
> #include "ext4.h"
>
> -#define NUM_PREALLOC_POST_READ_CTXS 128
> -
> -static struct kmem_cache *bio_post_read_ctx_cache;
> -static mempool_t *bio_post_read_ctx_pool;
> -
> static inline bool ext4_bio_encrypted(struct bio *bio)
> {
> #ifdef CONFIG_FS_ENCRYPTION
> @@ -61,125 +57,6 @@ static inline bool ext4_bio_encrypted(struct bio *bio)
> #endif
> }
>
> -/* postprocessing steps for read bios */
> -enum bio_post_read_step {
> - STEP_INITIAL = 0,
> - STEP_DECRYPT,
> - STEP_VERITY,
> -};
> -
> -struct bio_post_read_ctx {
> - struct bio *bio;
> - struct work_struct work;
> - unsigned int cur_step;
> - unsigned int enabled_steps;
> -};
> -
> -static void __read_end_io(struct bio *bio)
> -{
> - struct page *page;
> - struct bio_vec *bv;
> - int i;
> - struct bvec_iter_all iter_all;
> -
> - bio_for_each_segment_all(bv, bio, i, iter_all) {
> - page = bv->bv_page;
> -
> - /* PG_error was set if any post_read step failed */
> - if (bio->bi_status || PageError(page)) {
> - ClearPageUptodate(page);
> - SetPageError(page);
> - } else {
> - SetPageUptodate(page);
> - }
> - unlock_page(page);
> - }
> - if (bio->bi_private)
> - mempool_free(bio->bi_private, bio_post_read_ctx_pool);
> - bio_put(bio);
> -}
> -
> -static void bio_post_read_processing(struct bio_post_read_ctx *ctx);
> -
> -static void decrypt_work(struct work_struct *work)
> -{
> - struct bio_post_read_ctx *ctx =
> - container_of(work, struct bio_post_read_ctx, work);
> -
> - fscrypt_decrypt_bio(ctx->bio);
> -
> - bio_post_read_processing(ctx);
> -}
> -
> -static void verity_work(struct work_struct *work)
> -{
> - struct bio_post_read_ctx *ctx =
> - container_of(work, struct bio_post_read_ctx, work);
> -
> - fsverity_verify_bio(ctx->bio);
> -
> - bio_post_read_processing(ctx);
> -}
> -
> -static void bio_post_read_processing(struct bio_post_read_ctx *ctx)
> -{
> - /*
> - * We use different work queues for decryption and for verity because
> - * verity may require reading metadata pages that need decryption, and
> - * we shouldn't recurse to the same workqueue.
> - */
> - switch (++ctx->cur_step) {
> - case STEP_DECRYPT:
> - if (ctx->enabled_steps & (1 << STEP_DECRYPT)) {
> - INIT_WORK(&ctx->work, decrypt_work);
> - fscrypt_enqueue_decrypt_work(&ctx->work);
> - return;
> - }
> - ctx->cur_step++;
> - /* fall-through */
> - case STEP_VERITY:
> - if (ctx->enabled_steps & (1 << STEP_VERITY)) {
> - INIT_WORK(&ctx->work, verity_work);
> - fsverity_enqueue_verify_work(&ctx->work);
> - return;
> - }
> - ctx->cur_step++;
> - /* fall-through */
> - default:
> - __read_end_io(ctx->bio);
> - }
> -}
> -
> -static struct bio_post_read_ctx *get_bio_post_read_ctx(struct inode *inode,
> - struct bio *bio,
> - pgoff_t index)
> -{
> - unsigned int post_read_steps = 0;
> - struct bio_post_read_ctx *ctx = NULL;
> -
> - if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
> - post_read_steps |= 1 << STEP_DECRYPT;
> -#ifdef CONFIG_FS_VERITY
> - if (inode->i_verity_info != NULL &&
> - (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)))
> - post_read_steps |= 1 << STEP_VERITY;
> -#endif
> - if (post_read_steps) {
> - ctx = mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS);
> - if (!ctx)
> - return ERR_PTR(-ENOMEM);
> - ctx->bio = bio;
> - ctx->enabled_steps = post_read_steps;
> - bio->bi_private = ctx;
> - }
> - return ctx;
> -}
> -
> -static bool bio_post_read_required(struct bio *bio)
> -{
> - return bio->bi_private && !bio->bi_status;
> -}
> -
> /*
> * I/O completion handler for multipage BIOs.
> *
> @@ -194,14 +71,30 @@ static bool bio_post_read_required(struct bio *bio)
> */
> static void mpage_end_io(struct bio *bio)
> {
> - if (bio_post_read_required(bio)) {
> - struct bio_post_read_ctx *ctx = bio->bi_private;
> + struct bio_vec *bv;
> + int i;
> + struct bvec_iter_all iter_all;
> +#if defined(CONFIG_FS_ENCRYPTION) || defined(CONFIG_FS_VERITY)
> + if (read_callbacks_required(bio)) {
> + struct read_callbacks_ctx *ctx = bio->bi_private;
>
> - ctx->cur_step = STEP_INITIAL;
> - bio_post_read_processing(ctx);
> + read_callbacks(ctx);
> return;
> }
> - __read_end_io(bio);
> +#endif
> + bio_for_each_segment_all(bv, bio, i, iter_all) {
> + struct page *page = bv->bv_page;
> +
> + if (!bio->bi_status) {
> + SetPageUptodate(page);
> + } else {
> + ClearPageUptodate(page);
> + SetPageError(page);
> + }
> + unlock_page(page);
> + }
> +
> + bio_put(bio);
> }
>
> static inline loff_t ext4_readpage_limit(struct inode *inode)
> @@ -368,17 +261,19 @@ int ext4_mpage_readpages(struct address_space *mapping,
> bio = NULL;
> }
> if (bio == NULL) {
> - struct bio_post_read_ctx *ctx;
> + struct read_callbacks_ctx *ctx = NULL;
>
> bio = bio_alloc(GFP_KERNEL,
> min_t(int, nr_pages, BIO_MAX_PAGES));
> if (!bio)
> goto set_error_page;
> - ctx = get_bio_post_read_ctx(inode, bio, page->index);
> +#if defined(CONFIG_FS_ENCRYPTION) || defined(CONFIG_FS_VERITY)
> + ctx = get_read_callbacks_ctx(inode, bio, page->index);
> if (IS_ERR(ctx)) {
> bio_put(bio);
> goto set_error_page;
> }
> +#endif
> bio_set_dev(bio, bdev);
> bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);
> bio->bi_end_io = mpage_end_io;
> @@ -417,29 +312,3 @@ int ext4_mpage_readpages(struct address_space *mapping,
> submit_bio(bio);
> return 0;
> }
> -
> -int __init ext4_init_post_read_processing(void)
> -{
> - bio_post_read_ctx_cache =
> - kmem_cache_create("ext4_bio_post_read_ctx",
> - sizeof(struct bio_post_read_ctx), 0, 0, NULL);
> - if (!bio_post_read_ctx_cache)
> - goto fail;
> - bio_post_read_ctx_pool =
> - mempool_create_slab_pool(NUM_PREALLOC_POST_READ_CTXS,
> - bio_post_read_ctx_cache);
> - if (!bio_post_read_ctx_pool)
> - goto fail_free_cache;
> - return 0;
> -
> -fail_free_cache:
> - kmem_cache_destroy(bio_post_read_ctx_cache);
> -fail:
> - return -ENOMEM;
> -}
> -
> -void ext4_exit_post_read_processing(void)
> -{
> - mempool_destroy(bio_post_read_ctx_pool);
> - kmem_cache_destroy(bio_post_read_ctx_cache);
> -}
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 4ae6f5849caa..aba724f82cc3 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -6101,10 +6101,6 @@ static int __init ext4_init_fs(void)
> return err;
>
> err = ext4_init_pending();
> - if (err)
> - goto out7;
> -
> - err = ext4_init_post_read_processing();
> if (err)
> goto out6;
>
> @@ -6146,10 +6142,8 @@ static int __init ext4_init_fs(void)
> out4:
> ext4_exit_pageio();
> out5:
> - ext4_exit_post_read_processing();
> -out6:
> ext4_exit_pending();
> -out7:
> +out6:
> ext4_exit_es();
>
> return err;
> @@ -6166,7 +6160,6 @@ static void __exit ext4_exit_fs(void)
> ext4_exit_sysfs();
> ext4_exit_system_zone();
> ext4_exit_pageio();
> - ext4_exit_post_read_processing();
> ext4_exit_es();
> ext4_exit_pending();
> }
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 038b958d0fa9..05430d3650ab 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -18,6 +18,7 @@
> #include <linux/uio.h>
> #include <linux/cleancache.h>
> #include <linux/sched/signal.h>
> +#include <linux/read_callbacks.h>
>
> #include "f2fs.h"
> #include "node.h"
> @@ -25,11 +26,6 @@
> #include "trace.h"
> #include <trace/events/f2fs.h>
>
> -#define NUM_PREALLOC_POST_READ_CTXS 128
> -
> -static struct kmem_cache *bio_post_read_ctx_cache;
> -static mempool_t *bio_post_read_ctx_pool;
> -
> static bool __is_cp_guaranteed(struct page *page)
> {
> struct address_space *mapping = page->mapping;
> @@ -69,20 +65,6 @@ static enum count_type __read_io_type(struct page *page)
> return F2FS_RD_DATA;
> }
>
> -/* postprocessing steps for read bios */
> -enum bio_post_read_step {
> - STEP_INITIAL = 0,
> - STEP_DECRYPT,
> - STEP_VERITY,
> -};
> -
> -struct bio_post_read_ctx {
> - struct bio *bio;
> - struct work_struct work;
> - unsigned int cur_step;
> - unsigned int enabled_steps;
> -};
> -
> static void __read_end_io(struct bio *bio)
> {
> struct page *page;
> @@ -104,65 +86,16 @@ static void __read_end_io(struct bio *bio)
> dec_page_count(F2FS_P_SB(page), __read_io_type(page));
> unlock_page(page);
> }
> - if (bio->bi_private)
> - mempool_free(bio->bi_private, bio_post_read_ctx_pool);
> - bio_put(bio);
> -}
> -
> -static void bio_post_read_processing(struct bio_post_read_ctx *ctx);
>
> -static void decrypt_work(struct work_struct *work)
> -{
> - struct bio_post_read_ctx *ctx =
> - container_of(work, struct bio_post_read_ctx, work);
> -
> - fscrypt_decrypt_bio(ctx->bio);
> +#if defined(CONFIG_FS_ENCRYPTION) || defined(CONFIG_FS_VERITY)
> + if (bio->bi_private) {
> + struct read_callbacks_ctx *ctx;
>
> - bio_post_read_processing(ctx);
> -}
> -
> -static void verity_work(struct work_struct *work)
> -{
> - struct bio_post_read_ctx *ctx =
> - container_of(work, struct bio_post_read_ctx, work);
> -
> - fsverity_verify_bio(ctx->bio);
> -
> - bio_post_read_processing(ctx);
> -}
> -
> -static void bio_post_read_processing(struct bio_post_read_ctx *ctx)
> -{
> - /*
> - * We use different work queues for decryption and for verity because
> - * verity may require reading metadata pages that need decryption, and
> - * we shouldn't recurse to the same workqueue.
> - */
> - switch (++ctx->cur_step) {
> - case STEP_DECRYPT:
> - if (ctx->enabled_steps & (1 << STEP_DECRYPT)) {
> - INIT_WORK(&ctx->work, decrypt_work);
> - fscrypt_enqueue_decrypt_work(&ctx->work);
> - return;
> - }
> - ctx->cur_step++;
> - /* fall-through */
> - case STEP_VERITY:
> - if (ctx->enabled_steps & (1 << STEP_VERITY)) {
> - INIT_WORK(&ctx->work, verity_work);
> - fsverity_enqueue_verify_work(&ctx->work);
> - return;
> - }
> - ctx->cur_step++;
> - /* fall-through */
> - default:
> - __read_end_io(ctx->bio);
> + ctx = bio->bi_private;
> + put_read_callbacks_ctx(ctx);
> }
> -}
> -
> -static bool f2fs_bio_post_read_required(struct bio *bio)
> -{
> - return bio->bi_private && !bio->bi_status;
> +#endif
> + bio_put(bio);
> }
>
> static void f2fs_read_end_io(struct bio *bio)
> @@ -173,14 +106,12 @@ static void f2fs_read_end_io(struct bio *bio)
> bio->bi_status = BLK_STS_IOERR;
> }
>
> - if (f2fs_bio_post_read_required(bio)) {
> - struct bio_post_read_ctx *ctx = bio->bi_private;
> -
> - ctx->cur_step = STEP_INITIAL;
> - bio_post_read_processing(ctx);
> +#if defined(CONFIG_FS_ENCRYPTION) || defined(CONFIG_FS_VERITY)
> + if (!bio->bi_status && bio->bi_private) {
> + read_callbacks((struct read_callbacks_ctx *)(bio->bi_private));
> return;
Previously, in __read_end_io() we will decrease in-flight read IO count for each
page, but it looks in the case that if fscrypto or fsverity is on and there is
no IO error in end_io(), we will miss handling the count.
> @@ -104,65 +86,16 @@ static void __read_end_io(struct bio *bio)
> dec_page_count(F2FS_P_SB(page), __read_io_type(page));
Thanks,
> }
> -
> +#endif
> __read_end_io(bio);
> }
>
> @@ -582,9 +513,9 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
> {
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> struct bio *bio;
> - struct bio_post_read_ctx *ctx;
> - unsigned int post_read_steps = 0;
> -
> +#if defined(CONFIG_FS_ENCRYPTION) || defined(CONFIG_FS_VERITY)
> + struct read_callbacks_ctx *ctx;
> +#endif
> if (!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC))
> return ERR_PTR(-EFAULT);
>
> @@ -595,24 +526,13 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
> bio->bi_end_io = f2fs_read_end_io;
> bio_set_op_attrs(bio, REQ_OP_READ, op_flag);
>
> - if (f2fs_encrypted_file(inode))
> - post_read_steps |= 1 << STEP_DECRYPT;
> -#ifdef CONFIG_FS_VERITY
> - if (inode->i_verity_info != NULL &&
> - (first_idx < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)))
> - post_read_steps |= 1 << STEP_VERITY;
> -#endif
> - if (post_read_steps) {
> - ctx = mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS);
> - if (!ctx) {
> - bio_put(bio);
> - return ERR_PTR(-ENOMEM);
> - }
> - ctx->bio = bio;
> - ctx->enabled_steps = post_read_steps;
> - bio->bi_private = ctx;
> +#if defined(CONFIG_FS_ENCRYPTION) || defined(CONFIG_FS_VERITY)
> + ctx = get_read_callbacks_ctx(inode, bio, first_idx);
> + if (IS_ERR(ctx)) {
> + bio_put(bio);
> + return (struct bio *)ctx;
> }
> -
> +#endif
> return bio;
> }
>
> @@ -2894,29 +2814,3 @@ void f2fs_clear_page_cache_dirty_tag(struct page *page)
> PAGECACHE_TAG_DIRTY);
> xa_unlock_irqrestore(&mapping->i_pages, flags);
> }
> -
> -int __init f2fs_init_post_read_processing(void)
> -{
> - bio_post_read_ctx_cache =
> - kmem_cache_create("f2fs_bio_post_read_ctx",
> - sizeof(struct bio_post_read_ctx), 0, 0, NULL);
> - if (!bio_post_read_ctx_cache)
> - goto fail;
> - bio_post_read_ctx_pool =
> - mempool_create_slab_pool(NUM_PREALLOC_POST_READ_CTXS,
> - bio_post_read_ctx_cache);
> - if (!bio_post_read_ctx_pool)
> - goto fail_free_cache;
> - return 0;
> -
> -fail_free_cache:
> - kmem_cache_destroy(bio_post_read_ctx_cache);
> -fail:
> - return -ENOMEM;
> -}
> -
> -void __exit f2fs_destroy_post_read_processing(void)
> -{
> - mempool_destroy(bio_post_read_ctx_pool);
> - kmem_cache_destroy(bio_post_read_ctx_cache);
> -}
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 0e187f67b206..2f75f06c784a 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -3633,15 +3633,11 @@ static int __init init_f2fs_fs(void)
> err = register_filesystem(&f2fs_fs_type);
> if (err)
> goto free_shrinker;
> +
> f2fs_create_root_stats();
> - err = f2fs_init_post_read_processing();
> - if (err)
> - goto free_root_stats;
> +
> return 0;
>
> -free_root_stats:
> - f2fs_destroy_root_stats();
> - unregister_filesystem(&f2fs_fs_type);
> free_shrinker:
> unregister_shrinker(&f2fs_shrinker_info);
> free_sysfs:
> @@ -3662,7 +3658,6 @@ static int __init init_f2fs_fs(void)
>
> static void __exit exit_f2fs_fs(void)
> {
> - f2fs_destroy_post_read_processing();
> f2fs_destroy_root_stats();
> unregister_filesystem(&f2fs_fs_type);
> unregister_shrinker(&f2fs_shrinker_info);
> diff --git a/fs/read_callbacks.c b/fs/read_callbacks.c
> new file mode 100644
> index 000000000000..b6d5b95e67d7
> --- /dev/null
> +++ b/fs/read_callbacks.c
> @@ -0,0 +1,136 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * This file tracks the state machine that needs to be executed after reading
> + * data from files that are encrypted and/or have verity metadata associated
> + * with them.
> + */
> +#include <linux/module.h>
> +#include <linux/mm.h>
> +#include <linux/pagemap.h>
> +#include <linux/bio.h>
> +#include <linux/fscrypt.h>
> +#include <linux/fsverity.h>
> +#include <linux/read_callbacks.h>
> +
> +#define NUM_PREALLOC_POST_READ_CTXS 128
> +
> +static struct kmem_cache *read_callbacks_ctx_cache;
> +static mempool_t *read_callbacks_ctx_pool;
> +
> +/* Read callback state machine steps */
> +enum read_callbacks_step {
> + STEP_INITIAL = 0,
> + STEP_DECRYPT,
> + STEP_VERITY,
> +};
> +
> +void end_read_callbacks(struct bio *bio)
> +{
> + struct page *page;
> + struct bio_vec *bv;
> + int i;
> + struct bvec_iter_all iter_all;
> +
> + bio_for_each_segment_all(bv, bio, i, iter_all) {
> + page = bv->bv_page;
> +
> + BUG_ON(bio->bi_status);
> +
> + if (!PageError(page))
> + SetPageUptodate(page);
> +
> + unlock_page(page);
> + }
> + if (bio->bi_private)
> + put_read_callbacks_ctx(bio->bi_private);
> + bio_put(bio);
> +}
> +EXPORT_SYMBOL(end_read_callbacks);
> +
> +void read_callbacks(struct read_callbacks_ctx *ctx)
> +{
> + /*
> + * We use different work queues for decryption and for verity because
> + * verity may require reading metadata pages that need decryption, and
> + * we shouldn't recurse to the same workqueue.
> + */
> + switch (++ctx->cur_step) {
> + case STEP_DECRYPT:
> + if (ctx->enabled_steps & (1 << STEP_DECRYPT)) {
> + fscrypt_enqueue_decrypt_work(&ctx->work);
> + return;
> + }
> + ctx->cur_step++;
> + /* fall-through */
> + case STEP_VERITY:
> + if (ctx->enabled_steps & (1 << STEP_VERITY)) {
> + fsverity_enqueue_verify_work(&ctx->work);
> + return;
> + }
> + ctx->cur_step++;
> + /* fall-through */
> + default:
> + end_read_callbacks(ctx->bio);
> + }
> +}
> +EXPORT_SYMBOL(read_callbacks);
> +
> +struct read_callbacks_ctx *get_read_callbacks_ctx(struct inode *inode,
> + struct bio *bio,
> + pgoff_t index)
> +{
> + unsigned int read_callbacks_steps = 0;
> + struct read_callbacks_ctx *ctx = NULL;
> +
> + if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
> + read_callbacks_steps |= 1 << STEP_DECRYPT;
> +#ifdef CONFIG_FS_VERITY
> + if (inode->i_verity_info != NULL &&
> + (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)))
> + read_callbacks_steps |= 1 << STEP_VERITY;
> +#endif
> + if (read_callbacks_steps) {
> + ctx = mempool_alloc(read_callbacks_ctx_pool, GFP_NOFS);
> + if (!ctx)
> + return ERR_PTR(-ENOMEM);
> + ctx->bio = bio;
> + ctx->inode = inode;
> + ctx->enabled_steps = read_callbacks_steps;
> + ctx->cur_step = STEP_INITIAL;
> + bio->bi_private = ctx;
> + }
> + return ctx;
> +}
> +EXPORT_SYMBOL(get_read_callbacks_ctx);
> +
> +void put_read_callbacks_ctx(struct read_callbacks_ctx *ctx)
> +{
> + mempool_free(ctx, read_callbacks_ctx_pool);
> +}
> +EXPORT_SYMBOL(put_read_callbacks_ctx);
> +
> +bool read_callbacks_required(struct bio *bio)
> +{
> + return bio->bi_private && !bio->bi_status;
> +}
> +EXPORT_SYMBOL(read_callbacks_required);
> +
> +static int __init init_read_callbacks(void)
> +{
> + read_callbacks_ctx_cache = KMEM_CACHE(read_callbacks_ctx, 0);
> + if (!read_callbacks_ctx_cache)
> + goto fail;
> + read_callbacks_ctx_pool =
> + mempool_create_slab_pool(NUM_PREALLOC_POST_READ_CTXS,
> + read_callbacks_ctx_cache);
> + if (!read_callbacks_ctx_pool)
> + goto fail_free_cache;
> + return 0;
> +
> +fail_free_cache:
> + kmem_cache_destroy(read_callbacks_ctx_cache);
> +fail:
> + return -ENOMEM;
> +}
> +
> +fs_initcall(init_read_callbacks);
> diff --git a/fs/verity/Kconfig b/fs/verity/Kconfig
> index 563593fb42db..44784e57c99d 100644
> --- a/fs/verity/Kconfig
> +++ b/fs/verity/Kconfig
> @@ -4,6 +4,7 @@ config FS_VERITY
> # SHA-256 is selected as it's intended to be the default hash algorithm.
> # To avoid bloat, other wanted algorithms must be selected explicitly.
> select CRYPTO_SHA256
> + select FS_READ_CALLBACKS
> help
> This option enables fs-verity. fs-verity is the dm-verity
> mechanism implemented at the file level. On supported
> diff --git a/fs/verity/verify.c b/fs/verity/verify.c
> index 5732453a81e7..f93bee33872d 100644
> --- a/fs/verity/verify.c
> +++ b/fs/verity/verify.c
> @@ -13,6 +13,7 @@
> #include <linux/pagemap.h>
> #include <linux/ratelimit.h>
> #include <linux/scatterlist.h>
> +#include <linux/read_callbacks.h>
>
> struct workqueue_struct *fsverity_read_workqueue;
>
> @@ -284,6 +285,16 @@ void fsverity_verify_bio(struct bio *bio)
> EXPORT_SYMBOL_GPL(fsverity_verify_bio);
> #endif /* CONFIG_BLOCK */
>
> +static void fsverity_verify_work(struct work_struct *work)
> +{
> + struct read_callbacks_ctx *ctx =
> + container_of(work, struct read_callbacks_ctx, work);
> +
> + fsverity_verify_bio(ctx->bio);
> +
> + read_callbacks(ctx);
> +}
> +
> /**
> * fsverity_enqueue_verify_work - enqueue work on the fs-verity workqueue
> *
> @@ -291,6 +302,7 @@ EXPORT_SYMBOL_GPL(fsverity_verify_bio);
> */
> void fsverity_enqueue_verify_work(struct work_struct *work)
> {
> + INIT_WORK(work, fsverity_verify_work);
> queue_work(fsverity_read_workqueue, work);
> }
> EXPORT_SYMBOL_GPL(fsverity_enqueue_verify_work);
> diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
> index c00b764d6b8c..a760b7bd81d4 100644
> --- a/include/linux/fscrypt.h
> +++ b/include/linux/fscrypt.h
> @@ -68,11 +68,7 @@ struct fscrypt_ctx {
> struct {
> struct page *bounce_page; /* Ciphertext page */
> struct page *control_page; /* Original page */
> - } w;
> - struct {
> - struct bio *bio;
> - struct work_struct work;
> - } r;
> + };
> struct list_head free_list; /* Free list */
> };
> u8 flags; /* Flags */
> @@ -113,7 +109,7 @@ extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned in
>
> static inline struct page *fscrypt_control_page(struct page *page)
> {
> - return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
> + return ((struct fscrypt_ctx *)page_private(page))->control_page;
> }
>
> extern void fscrypt_restore_control_page(struct page *);
> @@ -218,9 +214,6 @@ 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 void fscrypt_pullback_bio_page(struct page **, bool);
> extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
> unsigned int);
> @@ -390,15 +383,6 @@ 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 void fscrypt_pullback_bio_page(struct page **page, bool restore)
> {
> diff --git a/include/linux/read_callbacks.h b/include/linux/read_callbacks.h
> new file mode 100644
> index 000000000000..c501cdf83a5b
> --- /dev/null
> +++ b/include/linux/read_callbacks.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _READ_CALLBACKS_H
> +#define _READ_CALLBACKS_H
> +
> +struct read_callbacks_ctx {
> + struct bio *bio;
> + struct inode *inode;
> + struct work_struct work;
> + unsigned int cur_step;
> + unsigned int enabled_steps;
> +};
> +
> +void end_read_callbacks(struct bio *bio);
> +void read_callbacks(struct read_callbacks_ctx *ctx);
> +struct read_callbacks_ctx *get_read_callbacks_ctx(struct inode *inode,
> + struct bio *bio,
> + pgoff_t index);
> +void put_read_callbacks_ctx(struct read_callbacks_ctx *ctx);
> +bool read_callbacks_required(struct bio *bio);
> +
> +#endif /* _READ_CALLBACKS_H */
>
