Searched hist:"457 b1e353c739af39159269723949f315320446c" (Results 1 – 2 of 2) sorted by relevance
/linux/Documentation/filesystems/ |
H A D | fscrypt.rst | diff 457b1e353c739af39159269723949f315320446c Thu Dec 26 16:42:16 CET 2019 Eric Biggers <ebiggers@google.com> 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 <ebiggers@google.com> Link: https://lore.kernel.org/r/20191226154216.4808-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
/linux/fs/ext4/ |
H A D | extents.c | diff 457b1e353c739af39159269723949f315320446c Thu Dec 26 16:42:16 CET 2019 Eric Biggers <ebiggers@google.com> 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 <ebiggers@google.com> Link: https://lore.kernel.org/r/20191226154216.4808-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|