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Diffstat (limited to 'fs/sysfs/dir.c')
-rw-r--r--fs/sysfs/dir.c83
1 files changed, 52 insertions, 31 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 2a7a3f5d1ca6..6b0bb00d4d2b 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -132,6 +132,24 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children);
}
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+/* Test for attributes that want to ignore lockdep for read-locking */
+static bool ignore_lockdep(struct sysfs_dirent *sd)
+{
+ return sysfs_type(sd) == SYSFS_KOBJ_ATTR &&
+ sd->s_attr.attr->ignore_lockdep;
+}
+
+#else
+
+static inline bool ignore_lockdep(struct sysfs_dirent *sd)
+{
+ return true;
+}
+
+#endif
+
/**
* sysfs_get_active - get an active reference to sysfs_dirent
* @sd: sysfs_dirent to get an active reference to
@@ -155,15 +173,17 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
return NULL;
t = atomic_cmpxchg(&sd->s_active, v, v + 1);
- if (likely(t == v)) {
- rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
- return sd;
- }
+ if (likely(t == v))
+ break;
if (t < 0)
return NULL;
cpu_relax();
}
+
+ if (likely(!ignore_lockdep(sd)))
+ rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
+ return sd;
}
/**
@@ -180,7 +200,8 @@ void sysfs_put_active(struct sysfs_dirent *sd)
if (unlikely(!sd))
return;
- rwsem_release(&sd->dep_map, 1, _RET_IP_);
+ if (likely(!ignore_lockdep(sd)))
+ rwsem_release(&sd->dep_map, 1, _RET_IP_);
v = atomic_dec_return(&sd->s_active);
if (likely(v != SD_DEACTIVATED_BIAS))
return;
@@ -279,15 +300,16 @@ void release_sysfs_dirent(struct sysfs_dirent * sd)
static int sysfs_dentry_delete(const struct dentry *dentry)
{
struct sysfs_dirent *sd = dentry->d_fsdata;
- return !!(sd->s_flags & SYSFS_FLAG_REMOVED);
+ return !(sd && !(sd->s_flags & SYSFS_FLAG_REMOVED));
}
-static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
+static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
{
struct sysfs_dirent *sd;
int is_dir;
+ int type;
- if (nd->flags & LOOKUP_RCU)
+ if (flags & LOOKUP_RCU)
return -ECHILD;
sd = dentry->d_fsdata;
@@ -305,6 +327,15 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
if (strcmp(dentry->d_name.name, sd->s_name) != 0)
goto out_bad;
+ /* The sysfs dirent has been moved to a different namespace */
+ type = KOBJ_NS_TYPE_NONE;
+ if (sd->s_parent) {
+ type = sysfs_ns_type(sd->s_parent);
+ if (type != KOBJ_NS_TYPE_NONE &&
+ sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns)
+ goto out_bad;
+ }
+
mutex_unlock(&sysfs_mutex);
out_valid:
return 1;
@@ -334,18 +365,15 @@ out_bad:
return 0;
}
-static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode)
+static void sysfs_dentry_release(struct dentry *dentry)
{
- struct sysfs_dirent * sd = dentry->d_fsdata;
-
- sysfs_put(sd);
- iput(inode);
+ sysfs_put(dentry->d_fsdata);
}
-static const struct dentry_operations sysfs_dentry_ops = {
+const struct dentry_operations sysfs_dentry_ops = {
.d_revalidate = sysfs_dentry_revalidate,
.d_delete = sysfs_dentry_delete,
- .d_iput = sysfs_dentry_iput,
+ .d_release = sysfs_dentry_release,
};
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
@@ -729,6 +757,9 @@ int sysfs_create_dir(struct kobject * kobj)
else
parent_sd = &sysfs_root;
+ if (!parent_sd)
+ return -ENOENT;
+
if (sysfs_ns_type(parent_sd))
ns = kobj->ktype->namespace(kobj);
type = sysfs_read_ns_type(kobj);
@@ -740,7 +771,7 @@ int sysfs_create_dir(struct kobject * kobj)
}
static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
- struct nameidata *nd)
+ unsigned int flags)
{
struct dentry *ret = NULL;
struct dentry *parent = dentry->d_parent;
@@ -762,6 +793,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
ret = ERR_PTR(-ENOENT);
goto out_unlock;
}
+ dentry->d_fsdata = sysfs_get(sd);
/* attach dentry and inode */
inode = sysfs_get_inode(dir->i_sb, sd);
@@ -771,16 +803,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
}
/* instantiate and hash dentry */
- ret = d_find_alias(inode);
- if (!ret) {
- d_set_d_op(dentry, &sysfs_dentry_ops);
- dentry->d_fsdata = sysfs_get(sd);
- d_add(dentry, inode);
- } else {
- d_move(ret, dentry);
- iput(inode);
- }
-
+ ret = d_materialise_unique(dentry, inode);
out_unlock:
mutex_unlock(&sysfs_mutex);
return ret;
@@ -855,7 +878,6 @@ int sysfs_rename(struct sysfs_dirent *sd,
struct sysfs_dirent *new_parent_sd, const void *new_ns,
const char *new_name)
{
- const char *dup_name = NULL;
int error;
mutex_lock(&sysfs_mutex);
@@ -872,13 +894,12 @@ int sysfs_rename(struct sysfs_dirent *sd,
/* rename sysfs_dirent */
if (strcmp(sd->s_name, new_name) != 0) {
error = -ENOMEM;
- new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+ new_name = kstrdup(new_name, GFP_KERNEL);
if (!new_name)
goto out;
- dup_name = sd->s_name;
+ kfree(sd->s_name);
sd->s_name = new_name;
- sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name);
}
/* Move to the appropriate place in the appropriate directories rbtree. */
@@ -886,13 +907,13 @@ int sysfs_rename(struct sysfs_dirent *sd,
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_ns = new_ns;
+ sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name);
sd->s_parent = new_parent_sd;
sysfs_link_sibling(sd);
error = 0;
out:
mutex_unlock(&sysfs_mutex);
- kfree(dup_name);
return error;
}
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-22 22:31:13 +0300