[PATCH 1/2] ovl: factor out ovl_get_aio_req

[yangerkun <yangerkun@xxxxxxxxxx>]

Factor out a common function to remove duplicate code in
ovl_read_iter/ovl_write_iter.

Signed-off-by: yangerkun <yangerkun@xxxxxxxxxx>
---
 fs/overlayfs/file.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index d081faa55e83..4ac3cd698c7d 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -282,6 +282,23 @@ static void ovl_aio_rw_complete(struct kiocb *iocb, long res, long res2)
 	orig_iocb->ki_complete(orig_iocb, res, res2);
 }
 
+static struct ovl_aio_req *ovl_get_aio_req(struct kiocb *iocb, struct fd *real, int ifl)
+{
+	struct ovl_aio_req *req;
+
+	req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
+	if (!req)
+		return NULL;
+
+	req->fd = *real;
+	real->flags = 0;
+	req->orig_iocb = iocb;
+	kiocb_clone(&req->iocb, iocb, real->file);
+	req->iocb.ki_flags = ifl;
+	req->iocb.ki_complete = ovl_aio_rw_complete;
+	return req;
+}
+
 static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct file *file = iocb->ki_filp;
@@ -304,15 +321,10 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 		struct ovl_aio_req *aio_req;
 
 		ret = -ENOMEM;
-		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
+		aio_req = ovl_get_aio_req(iocb, &real, iocb->ki_flags);
 		if (!aio_req)
 			goto out;
 
-		aio_req->fd = real;
-		real.flags = 0;
-		aio_req->orig_iocb = iocb;
-		kiocb_clone(&aio_req->iocb, iocb, real.file);
-		aio_req->iocb.ki_complete = ovl_aio_rw_complete;
 		ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter);
 		if (ret != -EIOCBQUEUED)
 			ovl_aio_cleanup_handler(aio_req);
@@ -364,7 +376,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 		struct ovl_aio_req *aio_req;
 
 		ret = -ENOMEM;
-		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
+		aio_req = ovl_get_aio_req(iocb, &real, ifl);
 		if (!aio_req)
 			goto out;
 
@@ -372,12 +384,6 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 		/* Pacify lockdep, same trick as done in aio_write() */
 		__sb_writers_release(file_inode(real.file)->i_sb,
 				     SB_FREEZE_WRITE);
-		aio_req->fd = real;
-		real.flags = 0;
-		aio_req->orig_iocb = iocb;
-		kiocb_clone(&aio_req->iocb, iocb, real.file);
-		aio_req->iocb.ki_flags = ifl;
-		aio_req->iocb.ki_complete = ovl_aio_rw_complete;
 		ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter);
 		if (ret != -EIOCBQUEUED)
 			ovl_aio_cleanup_handler(aio_req);
-- 
2.31.1