74d46992e0
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
146 lines
3.3 KiB
C
146 lines
3.3 KiB
C
/*
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* This contains encryption functions for per-file encryption.
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*
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* Copyright (C) 2015, Google, Inc.
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* Copyright (C) 2015, Motorola Mobility
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*
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* Written by Michael Halcrow, 2014.
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*
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* Filename encryption additions
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* Uday Savagaonkar, 2014
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* Encryption policy handling additions
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* Ildar Muslukhov, 2014
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* Add fscrypt_pullback_bio_page()
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* Jaegeuk Kim, 2015.
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*
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* This has not yet undergone a rigorous security audit.
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*
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* The usage of AES-XTS should conform to recommendations in NIST
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* Special Publication 800-38E and IEEE P1619/D16.
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*/
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#include <linux/pagemap.h>
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#include <linux/module.h>
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#include <linux/bio.h>
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#include <linux/namei.h>
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#include "fscrypt_private.h"
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/*
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* Call fscrypt_decrypt_page on every single page, reusing the encryption
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* context.
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*/
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static void completion_pages(struct work_struct *work)
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{
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struct fscrypt_ctx *ctx =
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container_of(work, struct fscrypt_ctx, r.work);
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struct bio *bio = ctx->r.bio;
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struct bio_vec *bv;
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int i;
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bio_for_each_segment_all(bv, bio, i) {
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struct page *page = bv->bv_page;
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int ret = fscrypt_decrypt_page(page->mapping->host, page,
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PAGE_SIZE, 0, page->index);
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if (ret) {
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WARN_ON_ONCE(1);
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SetPageError(page);
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} else {
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SetPageUptodate(page);
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}
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unlock_page(page);
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}
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fscrypt_release_ctx(ctx);
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bio_put(bio);
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}
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void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *ctx, struct bio *bio)
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{
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INIT_WORK(&ctx->r.work, completion_pages);
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ctx->r.bio = bio;
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queue_work(fscrypt_read_workqueue, &ctx->r.work);
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}
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EXPORT_SYMBOL(fscrypt_decrypt_bio_pages);
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void fscrypt_pullback_bio_page(struct page **page, bool restore)
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{
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struct fscrypt_ctx *ctx;
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struct page *bounce_page;
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/* The bounce data pages are unmapped. */
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if ((*page)->mapping)
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return;
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/* The bounce data page is unmapped. */
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bounce_page = *page;
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ctx = (struct fscrypt_ctx *)page_private(bounce_page);
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/* restore control page */
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*page = ctx->w.control_page;
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if (restore)
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fscrypt_restore_control_page(bounce_page);
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}
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EXPORT_SYMBOL(fscrypt_pullback_bio_page);
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int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
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sector_t pblk, unsigned int len)
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{
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struct fscrypt_ctx *ctx;
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struct page *ciphertext_page = NULL;
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struct bio *bio;
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int ret, err = 0;
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BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
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ctx = fscrypt_get_ctx(inode, GFP_NOFS);
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if (IS_ERR(ctx))
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return PTR_ERR(ctx);
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ciphertext_page = fscrypt_alloc_bounce_page(ctx, GFP_NOWAIT);
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if (IS_ERR(ciphertext_page)) {
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err = PTR_ERR(ciphertext_page);
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goto errout;
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}
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while (len--) {
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err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk,
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ZERO_PAGE(0), ciphertext_page,
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PAGE_SIZE, 0, GFP_NOFS);
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if (err)
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goto errout;
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bio = bio_alloc(GFP_NOWAIT, 1);
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if (!bio) {
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err = -ENOMEM;
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goto errout;
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}
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bio_set_dev(bio, inode->i_sb->s_bdev);
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bio->bi_iter.bi_sector =
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pblk << (inode->i_sb->s_blocksize_bits - 9);
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bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
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ret = bio_add_page(bio, ciphertext_page,
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inode->i_sb->s_blocksize, 0);
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if (ret != inode->i_sb->s_blocksize) {
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/* should never happen! */
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WARN_ON(1);
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bio_put(bio);
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err = -EIO;
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goto errout;
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}
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err = submit_bio_wait(bio);
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if (err == 0 && bio->bi_status)
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err = -EIO;
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bio_put(bio);
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if (err)
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goto errout;
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lblk++;
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pblk++;
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}
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err = 0;
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errout:
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fscrypt_release_ctx(ctx);
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return err;
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}
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EXPORT_SYMBOL(fscrypt_zeroout_range);
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