From: Jeuk Kim <[email protected]>
Inline encryption derives DUN from <inode, file offset>,
so bios from different inodes can't merge. With multi-threaded
buffered O_SYNC writes where each thread writes to its own file,
4KiB-per-page LBA allocation interleaves across inodes and
causes bio split. Serialize writeback for fscrypt inline-crypto
inodes via __should_serialize_io() to keep foreground writeback
focused on one inode and avoid split.
Test: fio --name=wb_osync --rw=write --bs=1M \
--time_based=1 --runtime=60s --size=2G \
--ioengine=psync --direct=0 --sync=1 \
--numjobs=8 --thread=1 --nrfiles=1 \
--filename_format='wb_osync.$jobnum'
device: UFS
Before -
write throughput: 675MiB/s
device I/O size distribution (by count, total 1027414):
4 KiB: 923139 (89.9%)
8 KiB: 84798 (8.3%)
≥512 KiB: 453 (0.0%)
After -
write throughput: 1760MiB/s
device I/O size distribution (by count, total 231750):
4 KiB: 16904 (7.3%)
8 KiB: 72128 (31.1%)
≥512 KiB: 118900 (51.3%)
Signed-off-by: Jeuk Kim <[email protected]>
---
fs/f2fs/data.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index ef38e62cda8f..ae6fb435d576 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3217,6 +3217,8 @@ static inline bool __should_serialize_io(struct inode
*inode,
if (f2fs_need_compress_data(inode))
return true;
+ if (fscrypt_inode_uses_inline_crypto(inode))
+ return true;
if (wbc->sync_mode != WB_SYNC_ALL)
return true;
if (get_dirty_pages(inode) >= SM_I(F2FS_I_SB(inode))->min_seq_blocks)
--
2.43.0
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