Merge tag '9p-for-5.17-rc1' of git://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:
 "Fixes, split 9p_net_fd, and new reviewer:

   - fix possible uninitialized memory usage for setattr

   - fix fscache reading hole in a file just after it's been grown

   - split net/9p/trans_fd.c in its own module like other transports.

     The new transport module defaults to 9P_NET and is autoloaded if
     required so users should not be impacted

   - add Christian Schoenebeck to 9p reviewers

   - some more trivial cleanup"

* tag '9p-for-5.17-rc1' of git://github.com/martinetd/linux:
  9p: fix enodata when reading growing file
  net/9p: show error message if user 'msize' cannot be satisfied
  MAINTAINERS: 9p: add Christian Schoenebeck as reviewer
  9p: only copy valid iattrs in 9P2000.L setattr implementation
  9p: Use BUG_ON instead of if condition followed by BUG.
  net/p9: load default transports
  9p/xen: autoload when xenbus service is available
  9p/trans_fd: split into dedicated module
  fs: 9p: remove unneeded variable
  9p/trans_virtio: Fix typo in the comment for p9_virtio_create()

3 files changed, 27 insertions, 13 deletions

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index c72e9f8f5f32..9a10e68c5f30 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -43,6 +43,11 @@ static void v9fs_req_issue_op(struct netfs_read_subrequest *subreq)
 	iov_iter_xarray(&to, READ, &rreq->mapping->i_pages, pos, len);
 
 	total = p9_client_read(fid, pos, &to, &err);
+
+	/* if we just extended the file size, any portion not in
+	 * cache won't be on server and is zeroes */
+	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+
 	netfs_subreq_terminated(subreq, err ?: total, false);
 }
 
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index be72ad9edb3e..2573c08f335c 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -115,7 +115,6 @@ out_error:
 
 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 {
-	int res = 0;
 	struct inode *inode = file_inode(filp);
 
 	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
@@ -125,7 +124,7 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 		invalidate_mapping_pages(&inode->i_data, 0, -1);
 	}
 
-	return res;
+	return 0;
 }
 
 static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
@@ -140,8 +139,7 @@ static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
 	fid = filp->private_data;
 	BUG_ON(fid == NULL);
 
-	if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
-		BUG();
+	BUG_ON((fl->fl_flags & FL_POSIX) != FL_POSIX);
 
 	res = locks_lock_file_wait(filp, fl);
 	if (res < 0)
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index cae301d09cd3..d17502a738a9 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -552,7 +552,10 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
 {
 	int retval, use_dentry = 0;
 	struct p9_fid *fid = NULL;
-	struct p9_iattr_dotl p9attr;
+	struct p9_iattr_dotl p9attr = {
+		.uid = INVALID_UID,
+		.gid = INVALID_GID,
+	};
 	struct inode *inode = d_inode(dentry);
 
 	p9_debug(P9_DEBUG_VFS, "\n");
@@ -562,14 +565,22 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
 		return retval;
 
 	p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
-	p9attr.mode = iattr->ia_mode;
-	p9attr.uid = iattr->ia_uid;
-	p9attr.gid = iattr->ia_gid;
-	p9attr.size = iattr->ia_size;
-	p9attr.atime_sec = iattr->ia_atime.tv_sec;
-	p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
-	p9attr.mtime_sec = iattr->ia_mtime.tv_sec;
-	p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec;
+	if (iattr->ia_valid & ATTR_MODE)
+		p9attr.mode = iattr->ia_mode;
+	if (iattr->ia_valid & ATTR_UID)
+		p9attr.uid = iattr->ia_uid;
+	if (iattr->ia_valid & ATTR_GID)
+		p9attr.gid = iattr->ia_gid;
+	if (iattr->ia_valid & ATTR_SIZE)
+		p9attr.size = iattr->ia_size;
+	if (iattr->ia_valid & ATTR_ATIME_SET) {
+		p9attr.atime_sec = iattr->ia_atime.tv_sec;
+		p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
+	}
+	if (iattr->ia_valid & ATTR_MTIME_SET) {
+		p9attr.mtime_sec = iattr->ia_mtime.tv_sec;
+		p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec;
+	}
 
 	if (iattr->ia_valid & ATTR_FILE) {
 		fid = iattr->ia_file->private_data;