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author | Michael Halcrow <mhalcrow@google.com> | 2015-04-12 06:55:10 +0200 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2015-04-12 06:55:10 +0200 |
commit | 2058f83a728adffbe00bded4f804b37a5ee58cbe (patch) | |
tree | e0bc1cf2aa8e3a36e9543567c5c248f785f88e2c /fs/ext4/page-io.c | |
parent | ext4 crypto: inherit encryption policies on inode and directory create (diff) | |
download | linux-2058f83a728adffbe00bded4f804b37a5ee58cbe.tar.xz linux-2058f83a728adffbe00bded4f804b37a5ee58cbe.zip |
ext4 crypto: implement the ext4 encryption write path
Pulls block_write_begin() into fs/ext4/inode.c because it might need
to do a low-level read of the existing data, in which case we need to
decrypt it.
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/page-io.c')
-rw-r--r-- | fs/ext4/page-io.c | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 5687e4750c1e..51a5f1214f48 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -67,6 +67,10 @@ static void ext4_finish_bio(struct bio *bio) bio_for_each_segment_all(bvec, bio, i) { struct page *page = bvec->bv_page; +#ifdef CONFIG_EXT4_FS_ENCRYPTION + struct page *data_page = NULL; + struct ext4_crypto_ctx *ctx = NULL; +#endif struct buffer_head *bh, *head; unsigned bio_start = bvec->bv_offset; unsigned bio_end = bio_start + bvec->bv_len; @@ -76,6 +80,15 @@ static void ext4_finish_bio(struct bio *bio) if (!page) continue; +#ifdef CONFIG_EXT4_FS_ENCRYPTION + if (!page->mapping) { + /* The bounce data pages are unmapped. */ + data_page = page; + ctx = (struct ext4_crypto_ctx *)page_private(data_page); + page = ctx->control_page; + } +#endif + if (error) { SetPageError(page); set_bit(AS_EIO, &page->mapping->flags); @@ -100,8 +113,13 @@ static void ext4_finish_bio(struct bio *bio) } while ((bh = bh->b_this_page) != head); bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); local_irq_restore(flags); - if (!under_io) + if (!under_io) { +#ifdef CONFIG_EXT4_FS_ENCRYPTION + if (ctx) + ext4_restore_control_page(data_page); +#endif end_page_writeback(page); + } } } @@ -376,6 +394,7 @@ static int io_submit_init_bio(struct ext4_io_submit *io, static int io_submit_add_bh(struct ext4_io_submit *io, struct inode *inode, + struct page *page, struct buffer_head *bh) { int ret; @@ -389,7 +408,7 @@ submit_and_retry: if (ret) return ret; } - ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); + ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh)); if (ret != bh->b_size) goto submit_and_retry; io->io_next_block++; @@ -402,6 +421,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, struct writeback_control *wbc, bool keep_towrite) { + struct page *data_page = NULL; struct inode *inode = page->mapping->host; unsigned block_start, blocksize; struct buffer_head *bh, *head; @@ -461,19 +481,29 @@ int ext4_bio_write_page(struct ext4_io_submit *io, set_buffer_async_write(bh); } while ((bh = bh->b_this_page) != head); - /* Now submit buffers to write */ bh = head = page_buffers(page); + + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { + data_page = ext4_encrypt(inode, page); + if (IS_ERR(data_page)) { + ret = PTR_ERR(data_page); + data_page = NULL; + goto out; + } + } + + /* Now submit buffers to write */ do { if (!buffer_async_write(bh)) continue; - ret = io_submit_add_bh(io, inode, bh); + ret = io_submit_add_bh(io, inode, + data_page ? data_page : page, bh); if (ret) { /* * We only get here on ENOMEM. Not much else * we can do but mark the page as dirty, and * better luck next time. */ - redirty_page_for_writepage(wbc, page); break; } nr_submitted++; @@ -482,6 +512,11 @@ int ext4_bio_write_page(struct ext4_io_submit *io, /* Error stopped previous loop? Clean up buffers... */ if (ret) { + out: + if (data_page) + ext4_restore_control_page(data_page); + printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); + redirty_page_for_writepage(wbc, page); do { clear_buffer_async_write(bh); bh = bh->b_this_page; |