This patch adds max_io_bytes to limit bio size when f2fs tries to merge
consecutive IOs. This can give a testing point to split out bios and check
end_io handles those bios correctly. This is used to capture a recent bug
on the decompression and fsverity flow.
Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
Documentation/ABI/testing/sysfs-fs-f2fs | 7 +++++++
fs/f2fs/data.c | 3 +++
fs/f2fs/f2fs.h | 1 +
fs/f2fs/sysfs.c | 2 ++
4 files changed, 13 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs
b/Documentation/ABI/testing/sysfs-fs-f2fs
index 67b3ed8e8c2f..3dfee94e0618 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -370,3 +370,10 @@ Date: April 2020
Contact: "Daeho Jeong" <daehoje...@google.com>
Description: Give a way to change iostat_period time. 3secs by default.
The new iostat trace gives stats gap given the period.
+What: /sys/fs/f2fs/<disk>/max_io_bytes
+Date: December 2020
+Contact: "Jaegeuk Kim" <jaeg...@kernel.org>
+Description: This gives a control to limit the bio size in f2fs.
+ Default is zero, which will follow underlying block layer limit,
+ whereas, if it has a certain bytes value, f2fs won't submit a
+ bio larger than that size.
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index e85fd8f77f3f..cb28089e1eff 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -736,6 +736,9 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
static bool page_is_mergeable(struct f2fs_sb_info *sbi, struct bio *bio,
block_t last_blkaddr, block_t cur_blkaddr)
{
+ if (unlikely(sbi->max_io_bytes &&
+ bio->bi_iter.bi_size >= sbi->max_io_bytes))
+ return false;
if (last_blkaddr + 1 != cur_blkaddr)
return false;
return __same_bdev(sbi, cur_blkaddr, bio);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 36090cd09011..594df6391390 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1446,6 +1446,7 @@ struct f2fs_sb_info {
loff_t max_file_blocks; /* max block index of file */
int dir_level; /* directory level */
int readdir_ra; /* readahead inode in readdir */
+ u64 max_io_bytes; /* max io bytes to merge IOs */
block_t user_block_count; /* # of user blocks */
block_t total_valid_block_count; /* # of valid blocks */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index fce2997382af..989a649cfa8b 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -567,6 +567,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info,
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_period_ms, iostat_period_ms);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_io_bytes, max_io_bytes);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh,
gc_pin_file_threshold);
F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list);
#ifdef CONFIG_F2FS_FAULT_INJECTION
@@ -651,6 +652,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(iostat_enable),
ATTR_LIST(iostat_period_ms),
ATTR_LIST(readdir_ra),
+ ATTR_LIST(max_io_bytes),
ATTR_LIST(gc_pin_file_thresh),
ATTR_LIST(extension_list),
#ifdef CONFIG_F2FS_FAULT_INJECTION
--
2.29.2.576.ga3fc446d84-goog
