fs: pass offset and result to backing_file end_write() callback

This is needed for extending fuse inode size after fuse passthrough write.

Suggested-by: Miklos Szeredi <[email protected]>
Link: https://lore.kernel.org/linux-fsdevel/CAJfpegs=cvZ_NYy6Q_D42XhYS=Sjj5poM1b5TzXzOVvX=R36aA@mail.gmail.com/
Signed-off-by: Amir Goldstein <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

Author: amir73il

fs/backing-file.c

@@ -80,7 +80,7 @@ struct backing_aio {
 	refcount_t ref;
 	struct kiocb *orig_iocb;
 	/* used for aio completion */
-	void (*end_write)(struct file *);
+	void (*end_write)(struct file *, loff_t, ssize_t);
 	struct work_struct work;
 	long res;
 };
@@ -109,7 +109,7 @@ static void backing_aio_cleanup(struct backing_aio *aio, long res)
 	struct kiocb *orig_iocb = aio->orig_iocb;
 
 	if (aio->end_write)
-		aio->end_write(orig_iocb->ki_filp);
+		aio->end_write(orig_iocb->ki_filp, iocb->ki_pos, res);
 
 	orig_iocb->ki_pos = iocb->ki_pos;
 	backing_aio_put(aio);
@@ -239,7 +239,7 @@ ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter,
 
 		ret = vfs_iter_write(file, iter, &iocb->ki_pos, rwf);
 		if (ctx->end_write)
-			ctx->end_write(ctx->user_file);
+			ctx->end_write(ctx->user_file, iocb->ki_pos, ret);
 	} else {
 		struct backing_aio *aio;
 
@@ -317,7 +317,7 @@ ssize_t backing_file_splice_write(struct pipe_inode_info *pipe,
 	revert_creds(old_cred);
 
 	if (ctx->end_write)
-		ctx->end_write(ctx->user_file);
+		ctx->end_write(ctx->user_file, ppos ? *ppos : 0, ret);
 
 	return ret;
 }

fs/fuse/passthrough.c

@@ -18,7 +18,7 @@ static void fuse_file_accessed(struct file *file)
 	fuse_invalidate_atime(inode);
 }
 
-static void fuse_file_modified(struct file *file)
+static void fuse_passthrough_end_write(struct file *file, loff_t pos, ssize_t ret)
 {
 	struct inode *inode = file_inode(file);
 
@@ -63,7 +63,7 @@ ssize_t fuse_passthrough_write_iter(struct kiocb *iocb,
 	struct backing_file_ctx ctx = {
 		.cred = ff->cred,
 		.user_file = file,
-		.end_write = fuse_file_modified,
+		.end_write = fuse_passthrough_end_write,
 	};
 
 	pr_debug("%s: backing_file=0x%p, pos=%lld, len=%zu\n", __func__,
@@ -110,7 +110,7 @@ ssize_t fuse_passthrough_splice_write(struct pipe_inode_info *pipe,
 	struct backing_file_ctx ctx = {
 		.cred = ff->cred,
 		.user_file = out,
-		.end_write = fuse_file_modified,
+		.end_write = fuse_passthrough_end_write,
 	};
 
 	pr_debug("%s: backing_file=0x%p, pos=%lld, len=%zu, flags=0x%x\n", __func__,

fs/overlayfs/file.c

@@ -231,6 +231,11 @@ static void ovl_file_modified(struct file *file)
 	ovl_copyattr(file_inode(file));
 }
 
+static void ovl_file_end_write(struct file *file, loff_t pos, ssize_t ret)
+{
+	ovl_file_modified(file);
+}
+
 static void ovl_file_accessed(struct file *file)
 {
 	struct inode *inode, *upperinode;
@@ -294,7 +299,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 	struct backing_file_ctx ctx = {
 		.cred = ovl_creds(inode->i_sb),
 		.user_file = file,
-		.end_write = ovl_file_modified,
+		.end_write = ovl_file_end_write,
 	};
 
 	if (!iov_iter_count(iter))
@@ -364,7 +369,7 @@ static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
 	struct backing_file_ctx ctx = {
 		.cred = ovl_creds(inode->i_sb),
 		.user_file = out,
-		.end_write = ovl_file_modified,
+		.end_write = ovl_file_end_write,
 	};
 
 	inode_lock(inode);

include/linux/backing-file.h

@@ -16,7 +16,7 @@ struct backing_file_ctx {
 	const struct cred *cred;
 	struct file *user_file;
 	void (*accessed)(struct file *);
-	void (*end_write)(struct file *);
+	void (*end_write)(struct file *, loff_t, ssize_t);
 };
 
 struct file *backing_file_open(const struct path *user_path, int flags,