[PATCH 2/9] fscrypt: keep multiple bios in flight in fscrypt_zeroout_range_inline_crypt
From: Christoph Hellwig <hch@lst.de>
Date: 2025-12-17 06:07:53
Also in:
linux-fscrypt, linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), fscrypt: file system level encryption support, the rest · Maintainers:
Alexander Viro, Christian Brauner, Eric Biggers, Theodore Y. Ts'o, Jaegeuk Kim, Linus Torvalds
This should slightly improve performance for large zeroing operations, but more importantly prepares for blk-crypto refactoring that requires all fscrypt users to call submit_bio directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Eric Biggers <ebiggers@kernel.org> --- fs/crypto/bio.c | 86 +++++++++++++++++++++++++++++++------------------ 1 file changed, 54 insertions(+), 32 deletions(-)
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index 68b0424d879a..c2b3ca100f8d 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c@@ -47,49 +47,71 @@ bool fscrypt_decrypt_bio(struct bio *bio) } EXPORT_SYMBOL(fscrypt_decrypt_bio); +struct fscrypt_zero_done { + atomic_t pending; + blk_status_t status; + struct completion done; +}; + +static void fscrypt_zeroout_range_done(struct fscrypt_zero_done *done) +{ + if (atomic_dec_and_test(&done->pending)) + complete(&done->done); +} + +static void fscrypt_zeroout_range_end_io(struct bio *bio) +{ + struct fscrypt_zero_done *done = bio->bi_private; + + if (bio->bi_status) + cmpxchg(&done->status, 0, bio->bi_status); + fscrypt_zeroout_range_done(done); + bio_put(bio); +} + static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode, pgoff_t lblk, sector_t sector, unsigned int len) { const unsigned int blockbits = inode->i_blkbits; const unsigned int blocks_per_page = 1 << (PAGE_SHIFT - blockbits); - struct bio *bio; - int ret, err = 0; - int num_pages = 0; - - /* This always succeeds since __GFP_DIRECT_RECLAIM is set. */ - bio = bio_alloc(inode->i_sb->s_bdev, BIO_MAX_VECS, REQ_OP_WRITE, - GFP_NOFS); + struct fscrypt_zero_done done = { + .pending = ATOMIC_INIT(1), + .done = COMPLETION_INITIALIZER_ONSTACK(done.done), + }; while (len) { - unsigned int blocks_this_page = min(len, blocks_per_page); - unsigned int bytes_this_page = blocks_this_page << blockbits; + struct bio *bio; + unsigned int n; - if (num_pages == 0) { - fscrypt_set_bio_crypt_ctx(bio, inode, lblk, GFP_NOFS); - bio->bi_iter.bi_sector = sector; - } - ret = bio_add_page(bio, ZERO_PAGE(0), bytes_this_page, 0); - if (WARN_ON_ONCE(ret != bytes_this_page)) { - err = -EIO; - goto out; - } - num_pages++; - len -= blocks_this_page; - lblk += blocks_this_page; - sector += (bytes_this_page >> SECTOR_SHIFT); - if (num_pages == BIO_MAX_VECS || !len || - !fscrypt_mergeable_bio(bio, inode, lblk)) { - err = submit_bio_wait(bio); - if (err) - goto out; - bio_reset(bio, inode->i_sb->s_bdev, REQ_OP_WRITE); - num_pages = 0; + bio = bio_alloc(inode->i_sb->s_bdev, BIO_MAX_VECS, REQ_OP_WRITE, + GFP_NOFS); + bio->bi_iter.bi_sector = sector; + bio->bi_private = &done; + bio->bi_end_io = fscrypt_zeroout_range_end_io; + fscrypt_set_bio_crypt_ctx(bio, inode, lblk, GFP_NOFS); + + for (n = 0; n < BIO_MAX_VECS; n++) { + unsigned int blocks_this_page = + min(len, blocks_per_page); + unsigned int bytes_this_page = blocks_this_page << blockbits; + + __bio_add_page(bio, ZERO_PAGE(0), bytes_this_page, 0); + len -= blocks_this_page; + lblk += blocks_this_page; + sector += (bytes_this_page >> SECTOR_SHIFT); + if (!len || !fscrypt_mergeable_bio(bio, inode, lblk)) + break; } + + atomic_inc(&done.pending); + submit_bio(bio); } -out: - bio_put(bio); - return err; + + fscrypt_zeroout_range_done(&done); + + wait_for_completion(&done.done); + return blk_status_to_errno(done.status); } /**
--
2.47.3