diff options
| -rw-r--r-- | fs/configfs/configfs_internal.h | 3 | ||||
| -rw-r--r-- | fs/configfs/dir.c | 90 | ||||
| -rw-r--r-- | fs/configfs/inode.c | 38 |
3 files changed, 131 insertions, 0 deletions
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h index 762d287123c..da6061a6df4 100644 --- a/fs/configfs/configfs_internal.h +++ b/fs/configfs/configfs_internal.h @@ -39,6 +39,9 @@ struct configfs_dirent { umode_t s_mode; struct dentry * s_dentry; struct iattr * s_iattr; +#ifdef CONFIG_LOCKDEP + int s_depth; +#endif }; #define CONFIGFS_ROOT 0x0001 diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 05373db21a4..d4d871fba21 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -78,6 +78,92 @@ static const struct dentry_operations configfs_dentry_ops = { .d_delete = configfs_d_delete, }; +#ifdef CONFIG_LOCKDEP + +/* + * Helpers to make lockdep happy with our recursive locking of default groups' + * inodes (see configfs_attach_group() and configfs_detach_group()). + * We put default groups i_mutexes in separate classes according to their depth + * from the youngest non-default group ancestor. + * + * For a non-default group A having default groups A/B, A/C, and A/C/D, default + * groups A/B and A/C will have their inode's mutex in class + * default_group_class[0], and default group A/C/D will be in + * default_group_class[1]. + * + * The lock classes are declared and assigned in inode.c, according to the + * s_depth value. + * The s_depth value is initialized to -1, adjusted to >= 0 when attaching + * default groups, and reset to -1 when all default groups are attached. During + * attachment, if configfs_create() sees s_depth > 0, the lock class of the new + * inode's mutex is set to default_group_class[s_depth - 1]. + */ + +static void configfs_init_dirent_depth(struct configfs_dirent *sd) +{ + sd->s_depth = -1; +} + +static void configfs_set_dir_dirent_depth(struct configfs_dirent *parent_sd, + struct configfs_dirent *sd) +{ + int parent_depth = parent_sd->s_depth; + + if (parent_depth >= 0) + sd->s_depth = parent_depth + 1; +} + +static void +configfs_adjust_dir_dirent_depth_before_populate(struct configfs_dirent *sd) +{ + /* + * item's i_mutex class is already setup, so s_depth is now only + * used to set new sub-directories s_depth, which is always done + * with item's i_mutex locked. + */ + /* + * sd->s_depth == -1 iff we are a non default group. + * else (we are a default group) sd->s_depth > 0 (see + * create_dir()). + */ + if (sd->s_depth == -1) + /* + * We are a non default group and we are going to create + * default groups. + */ + sd->s_depth = 0; +} + +static void +configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd) +{ + /* We will not create default groups anymore. */ + sd->s_depth = -1; +} + +#else /* CONFIG_LOCKDEP */ + +static void configfs_init_dirent_depth(struct configfs_dirent *sd) +{ +} + +static void configfs_set_dir_dirent_depth(struct configfs_dirent *parent_sd, + struct configfs_dirent *sd) +{ +} + +static void +configfs_adjust_dir_dirent_depth_before_populate(struct configfs_dirent *sd) +{ +} + +static void +configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd) +{ +} + +#endif /* CONFIG_LOCKDEP */ + /* * Allocates a new configfs_dirent and links it to the parent configfs_dirent */ @@ -94,6 +180,7 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * pare INIT_LIST_HEAD(&sd->s_links); INIT_LIST_HEAD(&sd->s_children); sd->s_element = element; + configfs_init_dirent_depth(sd); spin_lock(&configfs_dirent_lock); if (parent_sd->s_type & CONFIGFS_USET_DROPPING) { spin_unlock(&configfs_dirent_lock); @@ -187,6 +274,7 @@ static int create_dir(struct config_item * k, struct dentry * p, error = configfs_make_dirent(p->d_fsdata, d, k, mode, CONFIGFS_DIR | CONFIGFS_USET_CREATING); if (!error) { + configfs_set_dir_dirent_depth(p->d_fsdata, d->d_fsdata); error = configfs_create(d, mode, init_dir); if (!error) { inc_nlink(p->d_inode); @@ -789,11 +877,13 @@ static int configfs_attach_group(struct config_item *parent_item, * error, as rmdir() would. */ mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); + configfs_adjust_dir_dirent_depth_before_populate(sd); ret = populate_groups(to_config_group(item)); if (ret) { configfs_detach_item(item); dentry->d_inode->i_flags |= S_DEAD; } + configfs_adjust_dir_dirent_depth_after_populate(sd); mutex_unlock(&dentry->d_inode->i_mutex); if (ret) d_delete(dentry); diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c index 5d349d38e05..4921e7426d9 100644 --- a/fs/configfs/inode.c +++ b/fs/configfs/inode.c @@ -33,10 +33,15 @@ #include <linux/backing-dev.h> #include <linux/capability.h> #include <linux/sched.h> +#include <linux/lockdep.h> #include <linux/configfs.h> #include "configfs_internal.h" +#ifdef CONFIG_LOCKDEP +static struct lock_class_key default_group_class[MAX_LOCK_DEPTH]; +#endif + extern struct super_block * configfs_sb; static const struct address_space_operations configfs_aops = { @@ -150,6 +155,38 @@ struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd) return inode; } +#ifdef CONFIG_LOCKDEP + +static void configfs_set_inode_lock_class(struct configfs_dirent *sd, + struct inode *inode) +{ + int depth = sd->s_depth; + + if (depth > 0) { + if (depth <= ARRAY_SIZE(default_group_class)) { + lockdep_set_class(&inode->i_mutex, + &default_group_class[depth - 1]); + } else { + /* + * In practice the maximum level of locking depth is + * already reached. Just inform about possible reasons. + */ + printk(KERN_INFO "configfs: Too many levels of inodes" + " for the locking correctness validator.\n"); + printk(KERN_INFO "Spurious warnings may appear.\n"); + } + } +} + +#else /* CONFIG_LOCKDEP */ + +static void configfs_set_inode_lock_class(struct configfs_dirent *sd, + struct inode *inode) +{ +} + +#endif /* CONFIG_LOCKDEP */ + int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *)) { int error = 0; @@ -162,6 +199,7 @@ int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode * struct inode *p_inode = dentry->d_parent->d_inode; p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; } + configfs_set_inode_lock_class(sd, inode); goto Proceed; } else |