From 517e64f57883bd63c5a4ab8b3d0d3ed68c55d0cf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:29 -0500 Subject: sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation Currently, sysfs_dirent active_ref lockdep annotation uses attribute->[s]key as the lockdep key, which forces kernfs_create_file_ns() to assume that sysfs_dirent->priv is pointing to a struct attribute which may not be true for non-sysfs users. This patch restructures the lockdep annotation such that * kernfs_ops contains lockdep_key which is used by default for files created kernfs_create_file_ns(). * kernfs_create_file_ns_key() is introduced which takes an extra @key argument. The created file will use the specified key for active_ref lockdep annotation. If NULL is specified, lockdep for the file is disabled. * sysfs_add_file_mode_ns() is updated to use kernfs_create_file_ns_key() with the appropriate key from the attribute or NULL if ignore_lockdep is set. This makes the lockdep annotation properly contained in kernfs while allowing sysfs to cleanly keep its current behavior. This patch doesn't introduce any behavior differences. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index a68cbef3a674..e4eca285b390 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -58,7 +58,7 @@ static struct sysfs_open_file *sysfs_of(struct file *file) */ static const struct kernfs_ops *kernfs_ops(struct sysfs_dirent *sd) { - if (!sysfs_ignore_lockdep(sd)) + if (sd->s_flags & SYSFS_FLAG_LOCKDEP) lockdep_assert_held(sd); return sd->s_attr.ops; } @@ -71,7 +71,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) { struct kobject *kobj = sd->s_parent->priv; - if (!sysfs_ignore_lockdep(sd)) + if (sd->s_flags & SYSFS_FLAG_LOCKDEP) lockdep_assert_held(sd); return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; } @@ -942,6 +942,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, const struct attribute *attr, bool is_bin, umode_t mode, const void *ns) { + struct lock_class_key *key = NULL; const struct kernfs_ops *ops; struct sysfs_dirent *sd; loff_t size; @@ -981,8 +982,12 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, size = battr->size; } - sd = kernfs_create_file_ns(dir_sd, attr->name, mode, size, - ops, (void *)attr, ns); +#ifdef CONFIG_DEBUG_LOCK_ALLOC + if (!attr->ignore_lockdep) + key = attr->key ?: (struct lock_class_key *)&attr->skey; +#endif + sd = kernfs_create_file_ns_key(dir_sd, attr->name, mode, size, + ops, (void *)attr, ns, key); if (IS_ERR(sd)) { if (PTR_ERR(sd) == -EEXIST) sysfs_warn_dup(dir_sd, attr->name); @@ -992,7 +997,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, } /** - * kernfs_create_file_ns - create a file + * kernfs_create_file_ns_key - create a file * @parent: directory to create the file in * @name: name of the file * @mode: mode of the file @@ -1000,14 +1005,16 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, * @ops: kernfs operations for the file * @priv: private data for the file * @ns: optional namespace tag of the file + * @key: lockdep key for the file's active_ref, %NULL to disable lockdep * * Returns the created node on success, ERR_PTR() value on error. */ -struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent, - const char *name, - umode_t mode, loff_t size, - const struct kernfs_ops *ops, - void *priv, const void *ns) +struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent, + const char *name, + umode_t mode, loff_t size, + const struct kernfs_ops *ops, + void *priv, const void *ns, + struct lock_class_key *key) { struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; @@ -1022,7 +1029,13 @@ struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent, sd->s_attr.size = size; sd->s_ns = ns; sd->priv = priv; - sysfs_dirent_init_lockdep(sd); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + if (key) { + lockdep_init_map(&sd->dep_map, "s_active", key, 0); + sd->s_flags |= SYSFS_FLAG_LOCKDEP; + } +#endif /* * sd->s_attr.ops is accesible only while holding active ref. We -- cgit v1.2.3