From 95f58823a66d2281605c2cfb312e4d059118baee Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 28 Jan 2022 15:39:39 -0800 Subject: [PATCH] f2fs: support direct I/O with fscrypt using blk-crypto Encrypted files traditionally haven't supported DIO, due to the need to encrypt/decrypt the data. However, when the encryption is implemented using inline encryption (blk-crypto) instead of the traditional filesystem-layer encryption, it is straightforward to support DIO. Therefore, make f2fs support DIO on files that are using inline encryption. Since f2fs uses iomap for DIO, and fscrypt support was already added to iomap DIO, this just requires two small changes: - Let DIO proceed when supported, by checking fscrypt_dio_supported() instead of assuming that encrypted files never support DIO. - In f2fs_iomap_begin(), use fscrypt_limit_io_blocks() to limit the length of the mapping in the rare case where a DUN discontiguity occurs in the middle of an extent. The iomap DIO implementation requires this, since it assumes that it can submit a bio covering (up to) the whole mapping, without checking fscrypt constraints itself. Co-developed-by: Satya Tangirala Signed-off-by: Satya Tangirala Acked-by: Jaegeuk Kim Link: https://lore.kernel.org/r/20220128233940.79464-5-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/f2fs/data.c | 7 +++++++ fs/f2fs/f2fs.h | 6 +++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 52bdf382858c..f9b28c59df86 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -4069,6 +4069,13 @@ static int f2fs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, iomap->offset = blks_to_bytes(inode, map.m_lblk); + /* + * When inline encryption is enabled, sometimes I/O to an encrypted file + * has to be broken up to guarantee DUN contiguity. Handle this by + * limiting the length of the mapping returned. + */ + map.m_len = fscrypt_limit_io_blocks(inode, map.m_lblk, map.m_len); + if (map.m_flags & (F2FS_MAP_MAPPED | F2FS_MAP_UNWRITTEN)) { iomap->length = blks_to_bytes(inode, map.m_len); if (map.m_flags & F2FS_MAP_MAPPED) { diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index ccaa6aac81bf..5d761e1b0a2a 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -4477,7 +4477,11 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, struct f2fs_sb_info *sbi = F2FS_I_SB(inode); int rw = iov_iter_rw(iter); - if (f2fs_post_read_required(inode)) + if (!fscrypt_dio_supported(iocb, iter)) + return true; + if (fsverity_active(inode)) + return true; + if (f2fs_compressed_file(inode)) return true; /* disallow direct IO if any of devices has unaligned blksize */