[PATCH v2 01/50] fuse_ctl_add_conn(): fix nlink breakage in case of early failure

[Al Viro]

fuse_ctl_remove_conn() used to decrement the link count of root
manually; that got subsumed by simple_recursive_removal(), but
in case when subdirectory creation has failed the latter won't
get called.

Just move the modification of parent's link count into
fuse_ctl_add_dentry() to keep the things simple.  Allows to
get rid of the nlink argument as well...

Fixes: fcaac5b42768 "fuse_ctl: use simple_recursive_removal()"
Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
---
 fs/fuse/control.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/fs/fuse/control.c b/fs/fuse/control.c
index bb407705603c..5247df896c5d 100644
--- a/fs/fuse/control.c
+++ b/fs/fuse/control.c
@@ -205,8 +205,7 @@ static const struct file_operations fuse_conn_congestion_threshold_ops = {
 
 static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
 					  struct fuse_conn *fc,
-					  const char *name,
-					  int mode, int nlink,
+					  const char *name, int mode,
 					  const struct inode_operations *iop,
 					  const struct file_operations *fop)
 {
@@ -232,7 +231,10 @@ static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
 	if (iop)
 		inode->i_op = iop;
 	inode->i_fop = fop;
-	set_nlink(inode, nlink);
+	if (S_ISDIR(mode)) {
+		inc_nlink(d_inode(parent));
+		inc_nlink(inode);
+	}
 	inode->i_private = fc;
 	d_add(dentry, inode);
 
@@ -252,22 +254,21 @@ int fuse_ctl_add_conn(struct fuse_conn *fc)
 		return 0;
 
 	parent = fuse_control_sb->s_root;
-	inc_nlink(d_inode(parent));
 	sprintf(name, "%u", fc->dev);
-	parent = fuse_ctl_add_dentry(parent, fc, name, S_IFDIR | 0500, 2,
+	parent = fuse_ctl_add_dentry(parent, fc, name, S_IFDIR | 0500,
 				     &simple_dir_inode_operations,
 				     &simple_dir_operations);
 	if (!parent)
 		goto err;
 
-	if (!fuse_ctl_add_dentry(parent, fc, "waiting", S_IFREG | 0400, 1,
+	if (!fuse_ctl_add_dentry(parent, fc, "waiting", S_IFREG | 0400,
 				 NULL, &fuse_ctl_waiting_ops) ||
-	    !fuse_ctl_add_dentry(parent, fc, "abort", S_IFREG | 0200, 1,
+	    !fuse_ctl_add_dentry(parent, fc, "abort", S_IFREG | 0200,
 				 NULL, &fuse_ctl_abort_ops) ||
 	    !fuse_ctl_add_dentry(parent, fc, "max_background", S_IFREG | 0600,
-				 1, NULL, &fuse_conn_max_background_ops) ||
+				 NULL, &fuse_conn_max_background_ops) ||
 	    !fuse_ctl_add_dentry(parent, fc, "congestion_threshold",
-				 S_IFREG | 0600, 1, NULL,
+				 S_IFREG | 0600, NULL,
 				 &fuse_conn_congestion_threshold_ops))
 		goto err;
 
-- 
2.47.3