From 10208567f11bd572331cbbcb9a89c61a143811a1 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 3 Dec 2020 09:52:45 -0800 Subject: [PATCH] f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size 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. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- 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" 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//max_io_bytes +Date: December 2020 +Contact: "Jaegeuk Kim" +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