[PATCH 5/6] aio: implement IOCB_CMD_FSYNC and IOCB_CMD_FDSYNC

Christoph Hellwig
2018-03-28T07:44:02Z

Simple workqueue offload for now, but prepared for adding a real aio_fsync
method if the need arises. Based on an earlier patch from Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/aio.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)

diff --git a/fs/aio.c b/fs/aio.c
index f35801d73e0b..fd6c72918a8e 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -156,6 +156,12 @@ struct kioctx {
unsigned id;
};

+struct fsync_iocb {
+ struct work_struct work;
+ struct file *file;
+ bool datasync;
+};
+
/*
* We use ki_cancel == KIOCB_CANCELLED to indicate that a kiocb has been either
* cancelled or completed (this makes a certain amount of sense because
@@ -172,6 +178,7 @@ struct kioctx {
struct aio_kiocb {
union {
struct kiocb rw;
+ struct fsync_iocb fsync;
};

struct kioctx *ki_ctx;
@@ -1565,6 +1572,43 @@ static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored,
return ret;
}

+static void aio_fsync_work(struct work_struct *work)
+{
+ struct fsync_iocb *req = container_of(work, struct fsync_iocb, work);
+ int ret;
+
+ ret = vfs_fsync(req->file, req->datasync);
+ fput(req->file);
+ aio_complete(container_of(req, struct aio_kiocb, fsync), ret, 0);
+}
+
+static int aio_fsync(struct fsync_iocb *req, struct iocb *iocb, bool datasync)
+{
+ int ret;
+
+ if (iocb->aio_buf)
+ return -EINVAL;
+ if (iocb->aio_offset || iocb->aio_nbytes || iocb->aio_rw_flags)
+ return -EINVAL;
+
+ req->file = fget(iocb->aio_fildes);
+ if (unlikely(!req->file))
+ return -EBADF;
+
+ ret = -EINVAL;
+ if (!req->file->f_op->fsync)
+ goto out_fput;
+
+ req->datasync = datasync;
+ INIT_WORK(&req->work, aio_fsync_work);
+ schedule_work(&req->work);
+ return -EIOCBQUEUED;
+out_fput:
+ if (unlikely(ret && ret != -EIOCBQUEUED))
+ fput(req->file);
+ return ret;
+}
+
static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
struct iocb *iocb, bool compat)
{
@@ -1628,6 +1672,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
case IOCB_CMD_PWRITEV:
ret = aio_write(&req->rw, iocb, true, compat);
break;
+ case IOCB_CMD_FSYNC:
+ ret = aio_fsync(&req->fsync, iocb, false);
+ break;
+ case IOCB_CMD_FDSYNC:
+ ret = aio_fsync(&req->fsync, iocb, true);
+ break;
default:
pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
ret = -EINVAL;
--
2.14.2