1 files changed, 148 insertions, 14 deletions

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index e235a635d9ec..a5317216de73 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -9,8 +9,19 @@
 #include <linux/xattr.h>
 #include <linux/uio.h>
 #include <linux/uaccess.h>
+#include <linux/splice.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
 #include "overlayfs.h"
 
+struct ovl_aio_req {
+	struct kiocb iocb;
+	struct kiocb *orig_iocb;
+	struct fd fd;
+};
+
+static struct kmem_cache *ovl_aio_request_cachep;
+
 static char ovl_whatisit(struct inode *inode, struct inode *realinode)
 {
 	if (realinode != ovl_inode_upper(inode))
@@ -146,7 +157,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
 	struct inode *inode = file_inode(file);
 	struct fd real;
 	const struct cred *old_cred;
-	ssize_t ret;
+	loff_t ret;
 
 	/*
 	 * The two special cases below do not need to involve real fs,
@@ -171,7 +182,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
 	 * limitations that are more strict than ->s_maxbytes for specific
 	 * files, so we use the real file to perform seeks.
 	 */
-	inode_lock(inode);
+	ovl_inode_lock(inode);
 	real.file->f_pos = file->f_pos;
 
 	old_cred = ovl_override_creds(inode->i_sb);
@@ -179,7 +190,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
 	revert_creds(old_cred);
 
 	file->f_pos = real.file->f_pos;
-	inode_unlock(inode);
+	ovl_inode_unlock(inode);
 
 	fdput(real);
 
@@ -225,6 +236,33 @@ static rwf_t ovl_iocb_to_rwf(struct kiocb *iocb)
 	return flags;
 }
 
+static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
+{
+	struct kiocb *iocb = &aio_req->iocb;
+	struct kiocb *orig_iocb = aio_req->orig_iocb;
+
+	if (iocb->ki_flags & IOCB_WRITE) {
+		struct inode *inode = file_inode(orig_iocb->ki_filp);
+
+		file_end_write(iocb->ki_filp);
+		ovl_copyattr(ovl_inode_real(inode), inode);
+	}
+
+	orig_iocb->ki_pos = iocb->ki_pos;
+	fdput(aio_req->fd);
+	kmem_cache_free(ovl_aio_request_cachep, aio_req);
+}
+
+static void ovl_aio_rw_complete(struct kiocb *iocb, long res, long res2)
+{
+	struct ovl_aio_req *aio_req = container_of(iocb,
+						   struct ovl_aio_req, iocb);
+	struct kiocb *orig_iocb = aio_req->orig_iocb;
+
+	ovl_aio_cleanup_handler(aio_req);
+	orig_iocb->ki_complete(orig_iocb, res, res2);
+}
+
 static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct file *file = iocb->ki_filp;
@@ -240,10 +278,28 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 		return ret;
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
-			    ovl_iocb_to_rwf(iocb));
+	if (is_sync_kiocb(iocb)) {
+		ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
+				    ovl_iocb_to_rwf(iocb));
+	} else {
+		struct ovl_aio_req *aio_req;
+
+		ret = -ENOMEM;
+		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
+		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);
+	}
+out:
 	revert_creds(old_cred);
-
 	ovl_file_accessed(file);
 
 	fdput(real);
@@ -274,15 +330,33 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 		goto out_unlock;
 
 	old_cred = ovl_override_creds(file_inode(file)->i_sb);
-	file_start_write(real.file);
-	ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
-			     ovl_iocb_to_rwf(iocb));
-	file_end_write(real.file);
+	if (is_sync_kiocb(iocb)) {
+		file_start_write(real.file);
+		ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
+				     ovl_iocb_to_rwf(iocb));
+		file_end_write(real.file);
+		/* Update size */
+		ovl_copyattr(ovl_inode_real(inode), inode);
+	} else {
+		struct ovl_aio_req *aio_req;
+
+		ret = -ENOMEM;
+		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
+		if (!aio_req)
+			goto out;
+
+		file_start_write(real.file);
+		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_write(real.file, &aio_req->iocb, iter);
+		if (ret != -EIOCBQUEUED)
+			ovl_aio_cleanup_handler(aio_req);
+	}
+out:
 	revert_creds(old_cred);
-
-	/* Update size */
-	ovl_copyattr(ovl_inode_real(inode), inode);
-
 	fdput(real);
 
 out_unlock:
@@ -291,6 +365,48 @@ out_unlock:
 	return ret;
 }
 
+static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,
+			 struct pipe_inode_info *pipe, size_t len,
+			 unsigned int flags)
+{
+	ssize_t ret;
+	struct fd real;
+	const struct cred *old_cred;
+
+	ret = ovl_real_fdget(in, &real);
+	if (ret)
+		return ret;
+
+	old_cred = ovl_override_creds(file_inode(in)->i_sb);
+	ret = generic_file_splice_read(real.file, ppos, pipe, len, flags);
+	revert_creds(old_cred);
+
+	ovl_file_accessed(in);
+	fdput(real);
+	return ret;
+}
+
+static ssize_t
+ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
+			  loff_t *ppos, size_t len, unsigned int flags)
+{
+	struct fd real;
+	const struct cred *old_cred;
+	ssize_t ret;
+
+	ret = ovl_real_fdget(out, &real);
+	if (ret)
+		return ret;
+
+	old_cred = ovl_override_creds(file_inode(out)->i_sb);
+	ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);
+	revert_creds(old_cred);
+
+	ovl_file_accessed(out);
+	fdput(real);
+	return ret;
+}
+
 static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
 	struct fd real;
@@ -647,7 +763,25 @@ const struct file_operations ovl_file_operations = {
 	.fadvise	= ovl_fadvise,
 	.unlocked_ioctl	= ovl_ioctl,
 	.compat_ioctl	= ovl_compat_ioctl,
+	.splice_read    = ovl_splice_read,
+	.splice_write   = ovl_splice_write,
 
 	.copy_file_range	= ovl_copy_file_range,
 	.remap_file_range	= ovl_remap_file_range,
 };
+
+int __init ovl_aio_request_cache_init(void)
+{
+	ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req",
+						   sizeof(struct ovl_aio_req),
+						   0, SLAB_HWCACHE_ALIGN, NULL);
+	if (!ovl_aio_request_cachep)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void ovl_aio_request_cache_destroy(void)
+{
+	kmem_cache_destroy(ovl_aio_request_cachep);
+}