[PATCH] fuse: Track process write operations in both direct and writethrough modes

[Zhou Jifeng]

Due to the fact that fuse does not count the write IO of processes in the
direct and writethrough write modes, user processes cannot track
write_bytes through the “/proc/[pid]/io” path. For example, the system
tool iotop cannot count the write operations of the corresponding process.

Signed-off-by: Zhou Jifeng <zhoujifeng@xxxxxxxxxxxxxx>
---
 fs/fuse/file.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 1cdb6327511e..6051d2e2a021 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -19,6 +19,7 @@
 #include <linux/uio.h>
 #include <linux/fs.h>
 #include <linux/filelock.h>
+#include <linux/task_io_accounting_ops.h>
 
 static int fuse_send_open(struct fuse_mount *fm, u64 nodeid,
 			  unsigned int open_flags, int opcode,
@@ -1305,6 +1306,7 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	ssize_t written = 0;
 	struct inode *inode = mapping->host;
 	ssize_t err;
+	ssize_t count;
 	struct fuse_conn *fc = get_fuse_conn(inode);
 
 	if (fc->writeback_cache) {
@@ -1326,10 +1328,12 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
 writethrough:
 	inode_lock(inode);
 
-	err = generic_write_checks(iocb, from);
-	if (err <= 0)
+	count = generic_write_checks(iocb, from);
+	if (count <= 0)
 		goto out;
 
+	task_io_account_write(count);
+
 	err = file_remove_privs(file);
 	if (err)
 		goto out;
@@ -1600,6 +1604,7 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	res = generic_write_checks(iocb, from);
 	if (res > 0) {
+		task_io_account_write(res);
 		if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
 			res = fuse_direct_IO(iocb, from);
 		} else {
-- 
2.18.1