diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/debugfs/file.c | 2 | ||||
| -rw-r--r-- | fs/debugfs/inode.c | 39 | ||||
| -rw-r--r-- | fs/kernfs/file.c | 2 |
3 files changed, 31 insertions, 12 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 6314629..76c08c2 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -451,7 +451,7 @@ static ssize_t read_file_bool(struct file *file, char __user *user_buf, { char buf[3]; u32 *val = file->private_data; - + if (*val) buf[0] = 'Y'; else diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 8c41b52..1e3b99d 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -66,7 +66,7 @@ static struct inode *debugfs_get_inode(struct super_block *sb, umode_t mode, dev break; } } - return inode; + return inode; } /* SMP-safe */ @@ -317,7 +317,7 @@ static struct dentry *__create_file(const char *name, umode_t mode, goto exit; /* If the parent is not specified, we create it in the root. - * We need the root dentry to do this, which is in the super + * We need the root dentry to do this, which is in the super * block. A pointer to that is in the struct vfsmount that we * have around. */ @@ -330,7 +330,7 @@ static struct dentry *__create_file(const char *name, umode_t mode, switch (mode & S_IFMT) { case S_IFDIR: error = debugfs_mkdir(parent->d_inode, dentry, mode); - + break; case S_IFLNK: error = debugfs_link(parent->d_inode, dentry, mode, @@ -534,7 +534,7 @@ EXPORT_SYMBOL_GPL(debugfs_remove); */ void debugfs_remove_recursive(struct dentry *dentry) { - struct dentry *child, *next, *parent; + struct dentry *child, *parent; if (IS_ERR_OR_NULL(dentry)) return; @@ -546,30 +546,49 @@ void debugfs_remove_recursive(struct dentry *dentry) parent = dentry; down: mutex_lock(&parent->d_inode->i_mutex); - list_for_each_entry_safe(child, next, &parent->d_subdirs, d_u.d_child) { + loop: + /* + * The parent->d_subdirs is protected by the d_lock. Outside that + * lock, the child can be unlinked and set to be freed which can + * use the d_u.d_child as the rcu head and corrupt this list. + */ + spin_lock(&parent->d_lock); + list_for_each_entry(child, &parent->d_subdirs, d_u.d_child) { if (!debugfs_positive(child)) continue; /* perhaps simple_empty(child) makes more sense */ if (!list_empty(&child->d_subdirs)) { + spin_unlock(&parent->d_lock); mutex_unlock(&parent->d_inode->i_mutex); parent = child; goto down; } - up: + + spin_unlock(&parent->d_lock); + if (!__debugfs_remove(child, parent)) simple_release_fs(&debugfs_mount, &debugfs_mount_count); + + /* + * The parent->d_lock protects agaist child from unlinking + * from d_subdirs. When releasing the parent->d_lock we can + * no longer trust that the next pointer is valid. + * Restart the loop. We'll skip this one with the + * debugfs_positive() check. + */ + goto loop; } + spin_unlock(&parent->d_lock); mutex_unlock(&parent->d_inode->i_mutex); child = parent; parent = parent->d_parent; mutex_lock(&parent->d_inode->i_mutex); - if (child != dentry) { - next = list_next_entry(child, d_u.d_child); - goto up; - } + if (child != dentry) + /* go up */ + goto loop; if (!__debugfs_remove(child, parent)) simple_release_fs(&debugfs_mount, &debugfs_mount_count); diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index d895b4b..4429d6d 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -896,7 +896,7 @@ const struct file_operations kernfs_file_fops = { * @ops: kernfs operations for the file * @priv: private data for the file * @ns: optional namespace tag of the file - * @static_name: don't copy file name + * @name_is_static: don't copy file name * @key: lockdep key for the file's active_ref, %NULL to disable lockdep * * Returns the created node on success, ERR_PTR() value on error. |
