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-rw-r--r--fs/configfs/configfs_internal.h3
-rw-r--r--fs/configfs/dir.c90
-rw-r--r--fs/configfs/inode.c38
3 files changed, 131 insertions, 0 deletions
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h
index 762d287..da6061a 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 05373db..d4d871f 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 5d349d3..4921e742 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
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