[PATCH v4 01/54] fuse_ctl_add_conn(): fix nlink breakage in case of early failure
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2025-11-18 05:16:10
Also in:
bpf, linux-efi, linux-mm, linux-usb, linuxppc-dev, ocfs2-devel, selinux
Subsystem:
filesystems (vfs and infrastructure), fuse: filesystem in userspace, the rest · Maintainers:
Alexander Viro, Christian Brauner, Miklos Szeredi, Linus Torvalds
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()" Acked-by: Miklos Szeredi <redacted> Signed-off-by: Al Viro <viro@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