diff options
| -rw-r--r-- | fs/crypto/bio.c | 38 | ||||
| -rw-r--r-- | fs/crypto/crypto.c | 104 | ||||
| -rw-r--r-- | fs/crypto/fscrypt_private.h | 4 | ||||
| -rw-r--r-- | fs/ext4/page-io.c | 36 | ||||
| -rw-r--r-- | fs/f2fs/data.c | 12 | ||||
| -rw-r--r-- | include/linux/fscrypt.h | 38 |
6 files changed, 84 insertions, 148 deletions
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c index b46021ebde85..c857b70b5328 100644 --- a/fs/crypto/bio.c +++ b/fs/crypto/bio.c @@ -70,46 +70,18 @@ void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx, struct bio *bio) } EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio); -void fscrypt_pullback_bio_page(struct page **page, bool restore) -{ - struct fscrypt_ctx *ctx; - struct page *bounce_page; - - /* The bounce data pages are unmapped. */ - if ((*page)->mapping) - return; - - /* The bounce data page is unmapped. */ - bounce_page = *page; - ctx = (struct fscrypt_ctx *)page_private(bounce_page); - - /* restore control page */ - *page = ctx->w.control_page; - - if (restore) - fscrypt_restore_control_page(bounce_page); -} -EXPORT_SYMBOL(fscrypt_pullback_bio_page); - int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, sector_t pblk, unsigned int len) { - struct fscrypt_ctx *ctx; - struct page *ciphertext_page = NULL; + struct page *ciphertext_page; struct bio *bio; int ret, err = 0; BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE); - ctx = fscrypt_get_ctx(GFP_NOFS); - if (IS_ERR(ctx)) - return PTR_ERR(ctx); - - ciphertext_page = fscrypt_alloc_bounce_page(ctx, GFP_NOWAIT); - if (IS_ERR(ciphertext_page)) { - err = PTR_ERR(ciphertext_page); - goto errout; - } + ciphertext_page = fscrypt_alloc_bounce_page(GFP_NOWAIT); + if (!ciphertext_page) + return -ENOMEM; while (len--) { err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk, @@ -147,7 +119,7 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, } err = 0; errout: - fscrypt_release_ctx(ctx); + fscrypt_free_bounce_page(ciphertext_page); return err; } EXPORT_SYMBOL(fscrypt_zeroout_range); diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 335a362ee446..881e2a69f8a6 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -64,18 +64,11 @@ EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work); * * If the encryption context was allocated from the pre-allocated pool, returns * it to that pool. Else, frees it. - * - * If there's a bounce page in the context, this frees that. */ 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; - } - ctx->w.control_page = NULL; if (ctx->flags & FS_CTX_REQUIRES_FREE_ENCRYPT_FL) { kmem_cache_free(fscrypt_ctx_cachep, ctx); } else { @@ -100,14 +93,8 @@ struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags) unsigned long flags; /* - * We first try getting the ctx from a free list because in - * the common case the ctx will have an allocated and - * initialized crypto tfm, so it's probably a worthwhile - * optimization. For the bounce page, we first try getting it - * from the kernel allocator because that's just about as fast - * as getting it from a list and because a cache of free pages - * should generally be a "last resort" option for a filesystem - * to be able to do its job. + * 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, @@ -123,11 +110,31 @@ struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags) } else { ctx->flags &= ~FS_CTX_REQUIRES_FREE_ENCRYPT_FL; } - ctx->flags &= ~FS_CTX_HAS_BOUNCE_BUFFER_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); +} + +/** + * fscrypt_free_bounce_page() - free a ciphertext bounce page + * + * Free a bounce page that was allocated by fscrypt_encrypt_page(), or by + * fscrypt_alloc_bounce_page() directly. + */ +void fscrypt_free_bounce_page(struct page *bounce_page) +{ + if (!bounce_page) + return; + set_page_private(bounce_page, (unsigned long)NULL); + ClearPagePrivate(bounce_page); + mempool_free(bounce_page, fscrypt_bounce_page_pool); +} +EXPORT_SYMBOL(fscrypt_free_bounce_page); + void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num, const struct fscrypt_info *ci) { @@ -186,16 +193,6 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw, return 0; } -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) - return ERR_PTR(-ENOMEM); - 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 @@ -210,22 +207,12 @@ struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, * previously written data. * @gfp_flags: The gfp flag for memory allocation * - * 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. - * - * 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. - * - * 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. + * Encrypts @page. If the filesystem set FS_CFLG_OWN_PAGES, then the data is + * encrypted in-place and @page is returned. Else, a bounce page is allocated, + * the data is encrypted into the bounce page, and the bounce page is returned. + * The caller is responsible for calling fscrypt_free_bounce_page(). * - * Return: A page with the encrypted content on success. Else, an - * error value or NULL. + * Return: A page containing the encrypted data on success, else an ERR_PTR() */ struct page *fscrypt_encrypt_page(const struct inode *inode, struct page *page, @@ -234,7 +221,6 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, u64 lblk_num, gfp_t gfp_flags) { - struct fscrypt_ctx *ctx; struct page *ciphertext_page = page; int err; @@ -253,30 +239,20 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, BUG_ON(!PageLocked(page)); - ctx = fscrypt_get_ctx(gfp_flags); - if (IS_ERR(ctx)) - return ERR_CAST(ctx); - /* The encryption operation will require a bounce page. */ - ciphertext_page = fscrypt_alloc_bounce_page(ctx, gfp_flags); - if (IS_ERR(ciphertext_page)) - goto errout; + ciphertext_page = fscrypt_alloc_bounce_page(gfp_flags); + if (!ciphertext_page) + return ERR_PTR(-ENOMEM); - ctx->w.control_page = page; err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk_num, page, ciphertext_page, len, offs, gfp_flags); if (err) { - ciphertext_page = ERR_PTR(err); - goto errout; + fscrypt_free_bounce_page(ciphertext_page); + return ERR_PTR(err); } SetPagePrivate(ciphertext_page); - set_page_private(ciphertext_page, (unsigned long)ctx); - lock_page(ciphertext_page); - return ciphertext_page; - -errout: - fscrypt_release_ctx(ctx); + set_page_private(ciphertext_page, (unsigned long)page); return ciphertext_page; } EXPORT_SYMBOL(fscrypt_encrypt_page); @@ -355,18 +331,6 @@ const struct dentry_operations fscrypt_d_ops = { .d_revalidate = fscrypt_d_revalidate, }; -void fscrypt_restore_control_page(struct page *page) -{ - struct fscrypt_ctx *ctx; - - ctx = (struct fscrypt_ctx *)page_private(page); - set_page_private(page, (unsigned long)NULL); - ClearPagePrivate(page); - unlock_page(page); - fscrypt_release_ctx(ctx); -} -EXPORT_SYMBOL(fscrypt_restore_control_page); - static void fscrypt_destroy(void) { struct fscrypt_ctx *pos, *n; diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 7da276159593..4122ee1a0b7b 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -94,7 +94,6 @@ typedef enum { } 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) @@ -123,8 +122,7 @@ extern int fscrypt_do_page_crypto(const struct inode *inode, struct page *dest_page, unsigned int len, unsigned int offs, gfp_t gfp_flags); -extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, - gfp_t gfp_flags); +extern struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags); extern const struct dentry_operations fscrypt_d_ops; extern void __printf(3, 4) __cold diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 4690618a92e9..13d5ecc0af03 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -66,9 +66,7 @@ static void ext4_finish_bio(struct bio *bio) bio_for_each_segment_all(bvec, bio, iter_all) { struct page *page = bvec->bv_page; -#ifdef CONFIG_FS_ENCRYPTION - struct page *data_page = NULL; -#endif + struct page *bounce_page = NULL; struct buffer_head *bh, *head; unsigned bio_start = bvec->bv_offset; unsigned bio_end = bio_start + bvec->bv_len; @@ -78,13 +76,10 @@ static void ext4_finish_bio(struct bio *bio) if (!page) continue; -#ifdef CONFIG_FS_ENCRYPTION - if (!page->mapping) { - /* The bounce data pages are unmapped. */ - data_page = page; - fscrypt_pullback_bio_page(&page, false); + if (fscrypt_is_bounce_page(page)) { + bounce_page = page; + page = fscrypt_pagecache_page(bounce_page); } -#endif if (bio->bi_status) { SetPageError(page); @@ -111,10 +106,7 @@ static void ext4_finish_bio(struct bio *bio) bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); local_irq_restore(flags); if (!under_io) { -#ifdef CONFIG_FS_ENCRYPTION - if (data_page) - fscrypt_restore_control_page(data_page); -#endif + fscrypt_free_bounce_page(bounce_page); end_page_writeback(page); } } @@ -415,7 +407,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, struct writeback_control *wbc, bool keep_towrite) { - struct page *data_page = NULL; + struct page *bounce_page = NULL; struct inode *inode = page->mapping->host; unsigned block_start; struct buffer_head *bh, *head; @@ -479,10 +471,10 @@ int ext4_bio_write_page(struct ext4_io_submit *io, gfp_t gfp_flags = GFP_NOFS; retry_encrypt: - data_page = fscrypt_encrypt_page(inode, page, PAGE_SIZE, 0, - page->index, gfp_flags); - if (IS_ERR(data_page)) { - ret = PTR_ERR(data_page); + bounce_page = fscrypt_encrypt_page(inode, page, PAGE_SIZE, 0, + page->index, gfp_flags); + if (IS_ERR(bounce_page)) { + ret = PTR_ERR(bounce_page); if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) { if (io->io_bio) { ext4_io_submit(io); @@ -491,7 +483,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, gfp_flags |= __GFP_NOFAIL; goto retry_encrypt; } - data_page = NULL; + bounce_page = NULL; goto out; } } @@ -500,8 +492,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, do { if (!buffer_async_write(bh)) continue; - ret = io_submit_add_bh(io, inode, - data_page ? data_page : page, bh); + ret = io_submit_add_bh(io, inode, bounce_page ?: page, bh); if (ret) { /* * We only get here on ENOMEM. Not much else @@ -517,8 +508,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, /* Error stopped previous loop? Clean up buffers... */ if (ret) { out: - if (data_page) - fscrypt_restore_control_page(data_page); + fscrypt_free_bounce_page(bounce_page); printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); redirty_page_for_writepage(wbc, page); do { diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index eda4181d2092..968ebdbcb583 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -185,7 +185,7 @@ static void f2fs_write_end_io(struct bio *bio) continue; } - fscrypt_pullback_bio_page(&page, true); + fscrypt_finalize_bounce_page(&page); if (unlikely(bio->bi_status)) { mapping_set_error(page->mapping, -EIO); @@ -362,10 +362,9 @@ static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode, bio_for_each_segment_all(bvec, io->bio, iter_all) { - if (bvec->bv_page->mapping) - target = bvec->bv_page; - else - target = fscrypt_control_page(bvec->bv_page); + target = bvec->bv_page; + if (fscrypt_is_bounce_page(target)) + target = fscrypt_pagecache_page(target); if (inode && inode == target->mapping->host) return true; @@ -1900,8 +1899,7 @@ got_it: err = f2fs_inplace_write_data(fio); if (err) { if (f2fs_encrypted_file(inode)) - fscrypt_pullback_bio_page(&fio->encrypted_page, - true); + fscrypt_finalize_bounce_page(&fio->encrypted_page); if (PageWriteback(page)) end_page_writeback(page); } else { diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index f7680ef1abd2..d016fa384d60 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -112,12 +112,17 @@ extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *, extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int, unsigned int, u64); -static inline struct page *fscrypt_control_page(struct page *page) +static inline bool fscrypt_is_bounce_page(struct page *page) { - return ((struct fscrypt_ctx *)page_private(page))->w.control_page; + return page->mapping == NULL; } -extern void fscrypt_restore_control_page(struct page *); +static inline struct page *fscrypt_pagecache_page(struct page *bounce_page) +{ + return (struct page *)page_private(bounce_page); +} + +extern void fscrypt_free_bounce_page(struct page *bounce_page); /* policy.c */ extern int fscrypt_ioctl_set_policy(struct file *, const void __user *); @@ -223,7 +228,6 @@ static inline bool fscrypt_match_name(const struct fscrypt_name *fname, 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); @@ -300,15 +304,19 @@ static inline int fscrypt_decrypt_page(const struct inode *inode, return -EOPNOTSUPP; } -static inline struct page *fscrypt_control_page(struct page *page) +static inline bool fscrypt_is_bounce_page(struct page *page) +{ + return false; +} + +static inline struct page *fscrypt_pagecache_page(struct page *bounce_page) { WARN_ON_ONCE(1); return ERR_PTR(-EINVAL); } -static inline void fscrypt_restore_control_page(struct page *page) +static inline void fscrypt_free_bounce_page(struct page *bounce_page) { - return; } /* policy.c */ @@ -410,11 +418,6 @@ static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx, { } -static inline void fscrypt_pullback_bio_page(struct page **page, bool restore) -{ - return; -} - static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, sector_t pblk, unsigned int len) { @@ -692,4 +695,15 @@ static inline int fscrypt_encrypt_symlink(struct inode *inode, return 0; } +/* If *pagep is a bounce page, free it and set *pagep to the pagecache page */ +static inline void fscrypt_finalize_bounce_page(struct page **pagep) +{ + struct page *page = *pagep; + + if (fscrypt_is_bounce_page(page)) { + *pagep = fscrypt_pagecache_page(page); + fscrypt_free_bounce_page(page); + } +} + #endif /* _LINUX_FSCRYPT_H */ |