[PATCH v13 08/10] fuse: update inode size/mtime after passthrough write

[Amir Goldstein <amir73il@gmail.com>]

Similar to update size/mtime at the end of fuse_perform_write(),
we need to bump the attr version when we update the inode size.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 fs/fuse/passthrough.c | 53 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 11 deletions(-)

diff --git a/fs/fuse/passthrough.c b/fs/fuse/passthrough.c
index 10b370bcc423..8352d6b91e0e 100644
--- a/fs/fuse/passthrough.c
+++ b/fs/fuse/passthrough.c
@@ -14,15 +14,42 @@ struct fuse_aio_req {
 	struct kiocb *iocb_fuse;
 };
 
-static void fuse_aio_cleanup_handler(struct fuse_aio_req *aio_req)
+static void fuse_file_start_write(struct file *fuse_file,
+				  struct file *backing_file,
+				  loff_t pos, size_t count)
+{
+	struct inode *inode = file_inode(fuse_file);
+	struct fuse_inode *fi = get_fuse_inode(inode);
+
+	if (inode->i_size < pos + count)
+		set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+
+	file_start_write(backing_file);
+}
+
+static void fuse_file_end_write(struct file *fuse_file,
+				struct file *backing_file,
+				loff_t pos, ssize_t res)
+{
+	struct inode *inode = file_inode(fuse_file);
+	struct fuse_inode *fi = get_fuse_inode(inode);
+
+	file_end_write(backing_file);
+
+	fuse_write_update_attr(inode, pos, res);
+	clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+}
+
+static void fuse_aio_cleanup_handler(struct fuse_aio_req *aio_req, long res)
 {
 	struct kiocb *iocb = &aio_req->iocb;
 	struct kiocb *iocb_fuse = aio_req->iocb_fuse;
+	struct file *filp = iocb->ki_filp;
+	struct file *fuse_filp = iocb_fuse->ki_filp;
 
 	if (iocb->ki_flags & IOCB_WRITE) {
-		__sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb,
-				      SB_FREEZE_WRITE);
-		file_end_write(iocb->ki_filp);
+		__sb_writers_acquired(file_inode(filp)->i_sb, SB_FREEZE_WRITE);
+		fuse_file_end_write(fuse_filp, filp, iocb->ki_pos, res);
 	}
 
 	iocb_fuse->ki_pos = iocb->ki_pos;
@@ -35,7 +62,7 @@ static void fuse_aio_rw_complete(struct kiocb *iocb, long res)
 		container_of(iocb, struct fuse_aio_req, iocb);
 	struct kiocb *iocb_fuse = aio_req->iocb_fuse;
 
-	fuse_aio_cleanup_handler(aio_req);
+	fuse_aio_cleanup_handler(aio_req, res);
 	iocb_fuse->ki_complete(iocb_fuse, res);
 }
 
@@ -71,7 +98,7 @@ ssize_t fuse_passthrough_read_iter(struct kiocb *iocb_fuse,
 		aio_req->iocb.ki_complete = fuse_aio_rw_complete;
 		ret = call_read_iter(passthrough_filp, &aio_req->iocb, iter);
 		if (ret != -EIOCBQUEUED)
-			fuse_aio_cleanup_handler(aio_req);
+			fuse_aio_cleanup_handler(aio_req, ret);
 	}
 out:
 	revert_creds(old_cred);
@@ -87,22 +114,25 @@ ssize_t fuse_passthrough_write_iter(struct kiocb *iocb_fuse,
 	struct inode *fuse_inode = file_inode(fuse_filp);
 	struct file *passthrough_filp = ff->passthrough->filp;
 	struct inode *passthrough_inode = file_inode(passthrough_filp);
+	size_t count = iov_iter_count(iter);
 	const struct cred *old_cred;
 	ssize_t ret;
 	rwf_t rwf;
 
-	if (!iov_iter_count(iter))
+	if (!count)
 		return 0;
 
 	inode_lock(fuse_inode);
 
 	old_cred = override_creds(ff->passthrough->cred);
 	if (is_sync_kiocb(iocb_fuse)) {
-		file_start_write(passthrough_filp);
+		fuse_file_start_write(fuse_filp, passthrough_filp,
+				      iocb_fuse->ki_pos, count);
 		rwf = iocb_to_rw_flags(iocb_fuse->ki_flags, FUSE_IOCB_MASK);
 		ret = vfs_iter_write(passthrough_filp, iter, &iocb_fuse->ki_pos,
 				     rwf);
-		file_end_write(passthrough_filp);
+		fuse_file_end_write(fuse_filp, passthrough_filp,
+				    iocb_fuse->ki_pos, ret);
 	} else {
 		struct fuse_aio_req *aio_req;
 
@@ -112,7 +142,8 @@ ssize_t fuse_passthrough_write_iter(struct kiocb *iocb_fuse,
 			goto out;
 		}
 
-		file_start_write(passthrough_filp);
+		fuse_file_start_write(fuse_filp, passthrough_filp,
+				      iocb_fuse->ki_pos, count);
 		__sb_writers_release(passthrough_inode->i_sb, SB_FREEZE_WRITE);
 
 		aio_req->iocb_fuse = iocb_fuse;
@@ -120,7 +151,7 @@ ssize_t fuse_passthrough_write_iter(struct kiocb *iocb_fuse,
 		aio_req->iocb.ki_complete = fuse_aio_rw_complete;
 		ret = call_write_iter(passthrough_filp, &aio_req->iocb, iter);
 		if (ret != -EIOCBQUEUED)
-			fuse_aio_cleanup_handler(aio_req);
+			fuse_aio_cleanup_handler(aio_req, ret);
 	}
 out:
 	revert_creds(old_cred);
-- 
2.34.1