From 2fdff4c843907e0ad71d6d72d8303bb7199569f7 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 26 Dec 2019 09:40:07 -0600 Subject: docs: ext4.rst: add encryption and verity to features list Mention encryption and verity in the ext4 features list. Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20191226154007.4569-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o --- Documentation/admin-guide/ext4.rst | 2 ++ 1 file changed, 2 insertions(+) (limited to 'Documentation') diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst index 9bc93f0ce0c9..9443fcef1876 100644 --- a/Documentation/admin-guide/ext4.rst +++ b/Documentation/admin-guide/ext4.rst @@ -92,6 +92,8 @@ Currently Available * efficient new ordered mode in JBD2 and ext4 (avoid using buffer head to force the ordering) * Case-insensitive file name lookups +* file-based encryption support (fscrypt) +* file-based verity support (fsverity) [1] Filesystems with a block size of 1k may see a limit imposed by the directory hash tree having a maximum depth of two. -- cgit v1.2.3-59-g8ed1b From 457b1e353c739af39159269723949f315320446c Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 26 Dec 2019 09:42:16 -0600 Subject: ext4: allow ZERO_RANGE on encrypted files When ext4 encryption support was first added, ZERO_RANGE was disallowed, supposedly because test failures (e.g. ext4/001) were seen when enabling it, and at the time there wasn't enough time/interest to debug it. However, there's actually no reason why ZERO_RANGE can't work on encrypted files. And it fact it *does* work now. Whole blocks in the zeroed range are converted to unwritten extents, as usual; encryption makes no difference for that part. Partial blocks are zeroed in the pagecache and then ->writepages() encrypts those blocks as usual. ext4_block_zero_page_range() handles reading and decrypting the block if needed before actually doing the pagecache write. Also, f2fs has always supported ZERO_RANGE on encrypted files. As far as I can tell, the reason that ext4/001 was failing in v4.1 was actually because of one of the bugs fixed by commit 36086d43f657 ("ext4 crypto: fix bugs in ext4_encrypted_zeroout()"). The bug made ext4_encrypted_zeroout() always return a positive value, which caused unwritten extents in encrypted files to sometimes not be marked as initialized after being written to. This bug was not actually in ZERO_RANGE; it just happened to trigger during the extents manipulation done in ext4/001 (and probably other tests too). So, let's enable ZERO_RANGE on encrypted files on ext4. Tested with: gce-xfstests -c ext4/encrypt -g auto gce-xfstests -c ext4/encrypt_1k -g auto Got the same set of test failures both with and without this patch. But with this patch 6 fewer tests are skipped: ext4/001, generic/008, generic/009, generic/033, generic/096, and generic/511. Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20191226154216.4808-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o --- Documentation/filesystems/fscrypt.rst | 6 +++--- fs/ext4/extents.c | 7 +------ 2 files changed, 4 insertions(+), 9 deletions(-) (limited to 'Documentation') diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 68c2bc8275cf..07f1f15276bf 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -975,9 +975,9 @@ astute users may notice some differences in behavior: - Direct I/O is not supported on encrypted files. Attempts to use direct I/O on such files will fall back to buffered I/O. -- The fallocate operations FALLOC_FL_COLLAPSE_RANGE, - FALLOC_FL_INSERT_RANGE, and FALLOC_FL_ZERO_RANGE are not supported - on encrypted files and will fail with EOPNOTSUPP. +- The fallocate operations FALLOC_FL_COLLAPSE_RANGE and + FALLOC_FL_INSERT_RANGE are not supported on encrypted files and will + fail with EOPNOTSUPP. - Online defragmentation of encrypted files is not supported. The EXT4_IOC_MOVE_EXT and F2FS_IOC_MOVE_RANGE ioctls will fail with diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index a7f90470b1dc..4ba8215fa288 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4891,14 +4891,9 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) * range since we would need to re-encrypt blocks with a * different IV or XTS tweak (which are based on the logical * block number). - * - * XXX It's not clear why zero range isn't working, but we'll - * leave it disabled for encrypted inodes for now. This is a - * bug we should fix.... */ if (IS_ENCRYPTED(inode) && - (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE | - FALLOC_FL_ZERO_RANGE))) + (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE))) return -EOPNOTSUPP; /* Return error if mode is not supported */ -- cgit v1.2.3-59-g8ed1b