| Message ID | 20180212094347.22071-11-chandan@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On Mon, Feb 12, 2018 at 03:13:46PM +0530, Chandan Rajendra wrote: > This commit splits the functionality of fscrypt_encrypt_block(). The > allocation of fscrypt context and cipher text page is moved to a new > function fscrypt_prep_ciphertext_page(). > > ext4_bio_write_page() is modified to appropriately make use of the above > two functions. > > Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Well, this patch also modifies ext4_bio_write_page() to support the blocksize < pagesize case. The commit message makes it sound like it's just refactoring. > diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c > index 0a4a1e7..1e869d5 100644 > --- a/fs/ext4/page-io.c > +++ b/fs/ext4/page-io.c > @@ -419,9 +419,12 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > struct inode *inode = page->mapping->host; > unsigned block_start; > struct buffer_head *bh, *head; > + u64 blk_nr; > + gfp_t gfp_flags = GFP_NOFS; > int ret = 0; > int nr_submitted = 0; > int nr_to_submit = 0; > + int blocksize = (1 << inode->i_blkbits); > > BUG_ON(!PageLocked(page)); > BUG_ON(PageWriteback(page)); > @@ -475,15 +478,11 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > nr_to_submit++; > } while ((bh = bh->b_this_page) != head); > > - bh = head = page_buffers(page); > - > - if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) && > - nr_to_submit) { > - gfp_t gfp_flags = GFP_NOFS; > - > - retry_encrypt: > - data_page = fscrypt_encrypt_block(inode, page, PAGE_SIZE, 0, > - page->index, gfp_flags); > + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) > + && nr_to_submit) { > + retry_prep_ciphertext_page: > + data_page = fscrypt_prep_ciphertext_page(inode, page, > + gfp_flags); > if (IS_ERR(data_page)) { > ret = PTR_ERR(data_page); > if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) { > @@ -492,17 +491,28 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > congestion_wait(BLK_RW_ASYNC, HZ/50); > } > gfp_flags |= __GFP_NOFAIL; > - goto retry_encrypt; > + goto retry_prep_ciphertext_page; > } > data_page = NULL; > goto out; > } > } > > + blk_nr = page->index << (PAGE_SHIFT - inode->i_blkbits); > + > /* Now submit buffers to write */ > + bh = head = page_buffers(page); > do { > if (!buffer_async_write(bh)) > continue; > + > + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { > + ret = fscrypt_encrypt_block(inode, page, data_page, blocksize, > + bh_offset(bh), blk_nr, gfp_flags); > + if (ret) > + break; > + } > + > ret = io_submit_add_bh(io, inode, > data_page ? data_page : page, bh); > if (ret) { > @@ -515,12 +525,12 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > } > nr_submitted++; > clear_buffer_dirty(bh); > - } while ((bh = bh->b_this_page) != head); > + } while (++blk_nr, (bh = bh->b_this_page) != head); > > /* Error stopped previous loop? Clean up buffers... */ > if (ret) { > out: > - if (data_page) > + if (data_page && bh == head) > fscrypt_restore_control_page(data_page); > printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); > redirty_page_for_writepage(wbc, page); I'm wondering why you didn't move the crypto stuff in ext4_bio_write_page() into a separate function like I had suggested? It's true we don't have to encrypt all the blocks in the page at once, but it would make the crypto stuff more self-contained. - Eric -- To unsubscribe from this list: send the line "unsubscribe linux-fscrypt" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday, February 21, 2018 6:24:54 AM IST Eric Biggers wrote: > On Mon, Feb 12, 2018 at 03:13:46PM +0530, Chandan Rajendra wrote: > > This commit splits the functionality of fscrypt_encrypt_block(). The > > allocation of fscrypt context and cipher text page is moved to a new > > function fscrypt_prep_ciphertext_page(). > > > > ext4_bio_write_page() is modified to appropriately make use of the above > > two functions. > > > > Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> > > Well, this patch also modifies ext4_bio_write_page() to support the blocksize < > pagesize case. The commit message makes it sound like it's just refactoring. > > > diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c > > index 0a4a1e7..1e869d5 100644 > > --- a/fs/ext4/page-io.c > > +++ b/fs/ext4/page-io.c > > @@ -419,9 +419,12 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > > struct inode *inode = page->mapping->host; > > unsigned block_start; > > struct buffer_head *bh, *head; > > + u64 blk_nr; > > + gfp_t gfp_flags = GFP_NOFS; > > int ret = 0; > > int nr_submitted = 0; > > int nr_to_submit = 0; > > + int blocksize = (1 << inode->i_blkbits); > > > > BUG_ON(!PageLocked(page)); > > BUG_ON(PageWriteback(page)); > > @@ -475,15 +478,11 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > > nr_to_submit++; > > } while ((bh = bh->b_this_page) != head); > > > > - bh = head = page_buffers(page); > > - > > - if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) && > > - nr_to_submit) { > > - gfp_t gfp_flags = GFP_NOFS; > > - > > - retry_encrypt: > > - data_page = fscrypt_encrypt_block(inode, page, PAGE_SIZE, 0, > > - page->index, gfp_flags); > > + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) > > + && nr_to_submit) { > > + retry_prep_ciphertext_page: > > + data_page = fscrypt_prep_ciphertext_page(inode, page, > > + gfp_flags); > > if (IS_ERR(data_page)) { > > ret = PTR_ERR(data_page); > > if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) { > > @@ -492,17 +491,28 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > > congestion_wait(BLK_RW_ASYNC, HZ/50); > > } > > gfp_flags |= __GFP_NOFAIL; > > - goto retry_encrypt; > > + goto retry_prep_ciphertext_page; > > } > > data_page = NULL; > > goto out; > > } > > } > > > > + blk_nr = page->index << (PAGE_SHIFT - inode->i_blkbits); > > + > > /* Now submit buffers to write */ > > + bh = head = page_buffers(page); > > do { > > if (!buffer_async_write(bh)) > > continue; > > + > > + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { > > + ret = fscrypt_encrypt_block(inode, page, data_page, blocksize, > > + bh_offset(bh), blk_nr, gfp_flags); > > + if (ret) > > + break; > > + } > > + > > ret = io_submit_add_bh(io, inode, > > data_page ? data_page : page, bh); > > if (ret) { > > @@ -515,12 +525,12 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > > } > > nr_submitted++; > > clear_buffer_dirty(bh); > > - } while ((bh = bh->b_this_page) != head); > > + } while (++blk_nr, (bh = bh->b_this_page) != head); > > > > /* Error stopped previous loop? Clean up buffers... */ > > if (ret) { > > out: > > - if (data_page) > > + if (data_page && bh == head) > > fscrypt_restore_control_page(data_page); > > printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); > > redirty_page_for_writepage(wbc, page); > > I'm wondering why you didn't move the crypto stuff in ext4_bio_write_page() into > a separate function like I had suggested? It's true we don't have to encrypt > all the blocks in the page at once, but it would make the crypto stuff more > self-contained. Eric, Are you suggesting that the entire block of code that has invocations to fscrypt_prep_ciphertext_page() and fscrypt_encrypt_block() be moved to a separate function that gets defined in fscrypt module? If yes, In Ext4, We have the invocation of io_submit_add_bh() being interleaved with calls to fscrypt_encrypt_block().
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 24e3796..8fb27ee 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -195,6 +195,35 @@ struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, return ctx->w.bounce_page; } +struct page *fscrypt_prep_ciphertext_page(struct inode *inode, + struct page *page, + gfp_t gfp_flags) +{ + struct page *ciphertext_page; + struct fscrypt_ctx *ctx; + + BUG_ON(!PageLocked(page)); + + ctx = fscrypt_get_ctx(inode, gfp_flags); + if (IS_ERR(ctx)) + return ERR_CAST(ctx); + + ctx->w.control_page = page; + + ciphertext_page = fscrypt_alloc_bounce_page(ctx, gfp_flags); + if (IS_ERR(ciphertext_page)) { + fscrypt_release_ctx(ctx); + return ERR_CAST(ciphertext_page); + } + + SetPagePrivate(ciphertext_page); + set_page_private(ciphertext_page, (unsigned long)ctx); + lock_page(ciphertext_page); + + return ciphertext_page; +} +EXPORT_SYMBOL(fscrypt_prep_ciphertext_page); + /** * fscypt_encrypt_page() - Encrypts a page * @inode: The inode for which the encryption should take place @@ -226,15 +255,11 @@ struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, * Return: A page with the encrypted content on success. Else, an * error value or NULL. */ -struct page *fscrypt_encrypt_block(const struct inode *inode, - struct page *page, - unsigned int len, - unsigned int offs, - u64 lblk_num, gfp_t gfp_flags) - +int fscrypt_encrypt_block(const struct inode *inode, + struct page *page, struct page *ciphertext_page, + unsigned int len, unsigned int offs, + u64 lblk_num, gfp_t gfp_flags) { - struct fscrypt_ctx *ctx; - struct page *ciphertext_page = page; int err; BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0); @@ -242,41 +267,17 @@ struct page *fscrypt_encrypt_block(const struct inode *inode, if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) { /* with inplace-encryption we just encrypt the page */ err = fscrypt_do_block_crypto(inode, FS_ENCRYPT, lblk_num, page, - ciphertext_page, len, offs, - gfp_flags); - if (err) - return ERR_PTR(err); - - return ciphertext_page; + page, len, offs, gfp_flags); + return err; } BUG_ON(!PageLocked(page)); - ctx = fscrypt_get_ctx(inode, gfp_flags); - if (IS_ERR(ctx)) - return (struct page *)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; - - ctx->w.control_page = page; err = fscrypt_do_block_crypto(inode, FS_ENCRYPT, lblk_num, page, ciphertext_page, len, offs, gfp_flags); - if (err) { - ciphertext_page = ERR_PTR(err); - goto errout; - } - SetPagePrivate(ciphertext_page); - set_page_private(ciphertext_page, (unsigned long)ctx); - lock_page(ciphertext_page); - return ciphertext_page; + return err; -errout: - fscrypt_release_ctx(ctx); - return ciphertext_page; } EXPORT_SYMBOL(fscrypt_encrypt_block); diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 0a4a1e7..1e869d5 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -419,9 +419,12 @@ int ext4_bio_write_page(struct ext4_io_submit *io, struct inode *inode = page->mapping->host; unsigned block_start; struct buffer_head *bh, *head; + u64 blk_nr; + gfp_t gfp_flags = GFP_NOFS; int ret = 0; int nr_submitted = 0; int nr_to_submit = 0; + int blocksize = (1 << inode->i_blkbits); BUG_ON(!PageLocked(page)); BUG_ON(PageWriteback(page)); @@ -475,15 +478,11 @@ int ext4_bio_write_page(struct ext4_io_submit *io, nr_to_submit++; } while ((bh = bh->b_this_page) != head); - bh = head = page_buffers(page); - - if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) && - nr_to_submit) { - gfp_t gfp_flags = GFP_NOFS; - - retry_encrypt: - data_page = fscrypt_encrypt_block(inode, page, PAGE_SIZE, 0, - page->index, gfp_flags); + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) + && nr_to_submit) { + retry_prep_ciphertext_page: + data_page = fscrypt_prep_ciphertext_page(inode, page, + gfp_flags); if (IS_ERR(data_page)) { ret = PTR_ERR(data_page); if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) { @@ -492,17 +491,28 @@ int ext4_bio_write_page(struct ext4_io_submit *io, congestion_wait(BLK_RW_ASYNC, HZ/50); } gfp_flags |= __GFP_NOFAIL; - goto retry_encrypt; + goto retry_prep_ciphertext_page; } data_page = NULL; goto out; } } + blk_nr = page->index << (PAGE_SHIFT - inode->i_blkbits); + /* Now submit buffers to write */ + bh = head = page_buffers(page); do { if (!buffer_async_write(bh)) continue; + + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { + ret = fscrypt_encrypt_block(inode, page, data_page, blocksize, + bh_offset(bh), blk_nr, gfp_flags); + if (ret) + break; + } + ret = io_submit_add_bh(io, inode, data_page ? data_page : page, bh); if (ret) { @@ -515,12 +525,12 @@ int ext4_bio_write_page(struct ext4_io_submit *io, } nr_submitted++; clear_buffer_dirty(bh); - } while ((bh = bh->b_this_page) != head); + } while (++blk_nr, (bh = bh->b_this_page) != head); /* Error stopped previous loop? Clean up buffers... */ if (ret) { out: - if (data_page) + if (data_page && bh == head) fscrypt_restore_control_page(data_page); printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); redirty_page_for_writepage(wbc, page); diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h index aeb6b6d..3b0a53b 100644 --- a/include/linux/fscrypt_notsupp.h +++ b/include/linux/fscrypt_notsupp.h @@ -26,15 +26,21 @@ static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx) return; } -static inline struct page *fscrypt_encrypt_page(const struct inode *inode, - struct page *page, - unsigned int len, - unsigned int offs, - u64 lblk_num, gfp_t gfp_flags) +static inline struct page *fscrypt_prep_ciphertext_page(struct inode *inode, + struct page *page, + gfp_t gfp_flags) { return ERR_PTR(-EOPNOTSUPP); } +static inline int fscrypt_encrypt_block(const struct inode *inode, + struct page *page, struct page *ciphertext_page, + unsigned int len, unsigned int offs, + u64 lblk_num, gfp_t gfp_flags) +{ + return -EOPNOTSUPP; +} + static inline int fscrypt_decrypt_block(const struct inode *inode, struct page *page, unsigned int len, unsigned int offs, diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h index b4c5231..68a5e91 100644 --- a/include/linux/fscrypt_supp.h +++ b/include/linux/fscrypt_supp.h @@ -15,9 +15,12 @@ extern struct kmem_cache *fscrypt_info_cachep; extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t); extern void fscrypt_release_ctx(struct fscrypt_ctx *); -extern struct page *fscrypt_encrypt_block(const struct inode *, struct page *, - unsigned int, unsigned int, - u64, gfp_t); +extern struct page *fscrypt_prep_ciphertext_page(struct inode *, struct page *, + gfp_t); +extern int fscrypt_encrypt_block(const struct inode *inode, + struct page *page, struct page *ciphertext_page, + unsigned int len, unsigned int offs, + u64 lblk_num, gfp_t gfp_flags); extern int fscrypt_decrypt_block(const struct inode *, struct page *, unsigned int, unsigned int, u64); extern void fscrypt_restore_control_page(struct page *);
This commit splits the functionality of fscrypt_encrypt_block(). The allocation of fscrypt context and cipher text page is moved to a new function fscrypt_prep_ciphertext_page(). ext4_bio_write_page() is modified to appropriately make use of the above two functions. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> --- fs/crypto/crypto.c | 71 +++++++++++++++++++++-------------------- fs/ext4/page-io.c | 34 +++++++++++++------- include/linux/fscrypt_notsupp.h | 16 +++++++--- include/linux/fscrypt_supp.h | 9 ++++-- 4 files changed, 75 insertions(+), 55 deletions(-)