[PATCH v2] f2fs: add to account direct IO

From: Chao Yu
Date: Mon Nov 12 2018 - 09:00:30 EST


From: Chao Yu <yuchao0@xxxxxxxxxx>

This patch adds f2fs_dio_submit_bio() to hook submit_io/end_io functions
in direct IO path, in order to account DIO.

Later, we will add this count into is_idle() to let background GC/Discard
thread be aware of DIO.

Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
v2:
- access bio->bi_status instead of dead bio->bi_error.
fs/f2fs/data.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++-
fs/f2fs/debug.c | 4 ++++
fs/f2fs/f2fs.h | 10 ++++++++++
3 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 5245499203bf..6b30142c3321 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2604,6 +2604,53 @@ static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
return 0;
}

+static void f2fs_dio_end_io(struct bio *bio)
+{
+ struct f2fs_private_dio *dio = bio->bi_private;
+
+ dec_page_count(F2FS_I_SB(dio->inode),
+ dio->write ? F2FS_DIO_WRITE : F2FS_DIO_READ);
+
+ bio->bi_private = dio->orig_private;
+ bio->bi_end_io = dio->orig_end_io;
+
+ kfree(dio);
+
+ bio_endio(bio);
+}
+
+static void f2fs_dio_submit_bio(struct bio *bio, struct inode *inode,
+ loff_t file_offset)
+{
+ struct f2fs_private_dio *dio;
+ bool write = (bio_op(bio) == REQ_OP_WRITE);
+ int err;
+
+ dio = f2fs_kzalloc(F2FS_I_SB(inode),
+ sizeof(struct f2fs_private_dio), GFP_NOFS);
+ if (!dio) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ dio->inode = inode;
+ dio->orig_end_io = bio->bi_end_io;
+ dio->orig_private = bio->bi_private;
+ dio->write = write;
+
+ bio->bi_end_io = f2fs_dio_end_io;
+ bio->bi_private = dio;
+
+ inc_page_count(F2FS_I_SB(inode),
+ write ? F2FS_DIO_WRITE : F2FS_DIO_READ);
+
+ submit_bio(bio);
+ return;
+out:
+ bio->bi_status = BLK_STS_IOERR;
+ bio_endio(bio);
+}
+
static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct address_space *mapping = iocb->ki_filp->f_mapping;
@@ -2650,7 +2697,9 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
down_read(&fi->i_gc_rwsem[READ]);
}

- err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
+ err = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
+ iter, get_data_block_dio, NULL, f2fs_dio_submit_bio,
+ DIO_LOCKING | DIO_SKIP_HOLES);

if (do_opu)
up_read(&fi->i_gc_rwsem[READ]);
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index e327eefdbc02..06e72f9c8654 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -53,6 +53,8 @@ static void update_general_status(struct f2fs_sb_info *sbi)
si->vw_cnt = atomic_read(&sbi->vw_cnt);
si->max_aw_cnt = atomic_read(&sbi->max_aw_cnt);
si->max_vw_cnt = atomic_read(&sbi->max_vw_cnt);
+ si->nr_dio_read = get_pages(sbi, F2FS_DIO_READ);
+ si->nr_dio_write = get_pages(sbi, F2FS_DIO_WRITE);
si->nr_wb_cp_data = get_pages(sbi, F2FS_WB_CP_DATA);
si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA);
si->nr_rd_data = get_pages(sbi, F2FS_RD_DATA);
@@ -374,6 +376,8 @@ static int stat_show(struct seq_file *s, void *v)
seq_printf(s, " - Inner Struct Count: tree: %d(%d), node: %d\n",
si->ext_tree, si->zombie_tree, si->ext_node);
seq_puts(s, "\nBalancing F2FS Async:\n");
+ seq_printf(s, " - DIO (R: %4d, W: %4d)\n",
+ si->nr_dio_read, si->nr_dio_write);
seq_printf(s, " - IO_R (Data: %4d, Node: %4d, Meta: %4d\n",
si->nr_rd_data, si->nr_rd_node, si->nr_rd_meta);
seq_printf(s, " - IO_W (CP: %4d, Data: %4d, Flush: (%4d %4d %4d), "
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 70009709d50c..3a0fc17f1e7a 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -951,6 +951,8 @@ enum count_type {
F2FS_RD_DATA,
F2FS_RD_NODE,
F2FS_RD_META,
+ F2FS_DIO_WRITE,
+ F2FS_DIO_READ,
NR_COUNT_TYPE,
};

@@ -1340,6 +1342,13 @@ struct f2fs_sb_info {
__u32 s_chksum_seed;
};

+struct f2fs_private_dio {
+ struct inode *inode;
+ void *orig_private;
+ bio_end_io_t *orig_end_io;
+ bool write;
+};
+
#ifdef CONFIG_F2FS_FAULT_INJECTION
#define f2fs_show_injection_info(type) \
printk_ratelimited("%sF2FS-fs : inject %s in %s of %pF\n", \
@@ -3163,6 +3172,7 @@ struct f2fs_stat_info {
int total_count, utilization;
int bg_gc, nr_wb_cp_data, nr_wb_data;
int nr_rd_data, nr_rd_node, nr_rd_meta;
+ int nr_dio_read, nr_dio_write;
unsigned int io_skip_bggc, other_skip_bggc;
int nr_flushing, nr_flushed, flush_list_empty;
int nr_discarding, nr_discarded;
--
2.18.0