@@ -45,6 +45,7 @@ enum {
EVENTFS_SAVE_MODE = BIT(16),
EVENTFS_SAVE_UID = BIT(17),
EVENTFS_SAVE_GID = BIT(18),
+ EVENTFS_TOPLEVEL = BIT(19),
};
#define EVENTFS_MODE_MASK (EVENTFS_SAVE_MODE - 1)
@@ -115,10 +116,17 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
* The events directory dentry is never freed, unless its
* part of an instance that is deleted. It's attr is the
* default for its child files and directories.
- * Do not update it. It's not used for its own mode or ownership
+ * Do not update it. It's not used for its own mode or ownership.
*/
- if (!ei->is_events)
+ if (ei->is_events) {
+ /* But it still needs to know if it was modified */
+ if (iattr->ia_valid & ATTR_UID)
+ ei->attr.mode |= EVENTFS_SAVE_UID;
+ if (iattr->ia_valid & ATTR_GID)
+ ei->attr.mode |= EVENTFS_SAVE_GID;
+ } else {
update_attr(&ei->attr, iattr);
+ }
} else {
name = dentry->d_name.name;
@@ -136,9 +144,66 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
return ret;
}
+static void update_top_events_attr(struct eventfs_inode *ei, struct dentry *dentry)
+{
+ struct inode *inode;
+
+ /* Only update if the "events" was on the top level */
+ if (!ei || !(ei->attr.mode & EVENTFS_TOPLEVEL))
+ return;
+
+ /* Get the tracefs root inode. */
+ inode = d_inode(dentry->d_sb->s_root);
+ ei->attr.uid = inode->i_uid;
+ ei->attr.gid = inode->i_gid;
+}
+
+static void set_top_events_ownership(struct inode *inode)
+{
+ struct tracefs_inode *ti = get_tracefs(inode);
+ struct eventfs_inode *ei = ti->private;
+ struct dentry *dentry;
+
+ /* The top events directory doesn't get automatically updated */
+ if (!ei || !ei->is_events || !(ei->attr.mode & EVENTFS_TOPLEVEL))
+ return;
+
+ dentry = ei->dentry;
+
+ update_top_events_attr(ei, dentry);
+
+ if (!(ei->attr.mode & EVENTFS_SAVE_UID))
+ inode->i_uid = ei->attr.uid;
+
+ if (!(ei->attr.mode & EVENTFS_SAVE_GID))
+ inode->i_gid = ei->attr.gid;
+}
+
+static int eventfs_get_attr(struct mnt_idmap *idmap,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ struct dentry *dentry = path->dentry;
+ struct inode *inode = d_backing_inode(dentry);
+
+ set_top_events_ownership(inode);
+
+ generic_fillattr(idmap, request_mask, inode, stat);
+ return 0;
+}
+
+static int eventfs_permission(struct mnt_idmap *idmap,
+ struct inode *inode, int mask)
+{
+ set_top_events_ownership(inode);
+ return generic_permission(idmap, inode, mask);
+}
+
static const struct inode_operations eventfs_root_dir_inode_operations = {
.lookup = eventfs_root_lookup,
.setattr = eventfs_set_attr,
+ .getattr = eventfs_get_attr,
+ .permission = eventfs_permission,
};
static const struct inode_operations eventfs_file_inode_operations = {
@@ -174,6 +239,8 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry)
} while (!ei->is_events);
mutex_unlock(&eventfs_mutex);
+ update_top_events_attr(ei, dentry);
+
return ei;
}
@@ -887,6 +954,14 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry
uid = d_inode(dentry->d_parent)->i_uid;
gid = d_inode(dentry->d_parent)->i_gid;
+ /*
+ * If the events directory is of the top instance, then parent
+ * is NULL. Set the attr.mode to reflect this and its permissions will
+ * default to the tracefs root dentry.
+ */
+ if (!parent)
+ ei->attr.mode = EVENTFS_TOPLEVEL;
+
/* This is used as the default ownership of the files and directories */
ei->attr.uid = uid;
ei->attr.gid = gid;
@@ -91,6 +91,7 @@ static int tracefs_syscall_mkdir(struct mnt_idmap *idmap,
struct inode *inode, struct dentry *dentry,
umode_t mode)
{
+ struct tracefs_inode *ti;
char *name;
int ret;
@@ -98,6 +99,15 @@ static int tracefs_syscall_mkdir(struct mnt_idmap *idmap,
if (!name)
return -ENOMEM;
+ /*
+ * This is a new directory that does not take the default of
+ * the rootfs. It becomes the default permissions for all the
+ * files and directories underneath it.
+ */
+ ti = get_tracefs(inode);
+ ti->flags |= TRACEFS_INSTANCE_INODE;
+ ti->private = inode;
+
/*
* The mkdir call can call the generic functions that create
* the files within the tracefs system. It is up to the individual
@@ -141,10 +151,76 @@ static int tracefs_syscall_rmdir(struct inode *inode, struct dentry *dentry)
return ret;
}
-static const struct inode_operations tracefs_dir_inode_operations = {
+static void set_tracefs_inode_owner(struct inode *inode)
+{
+ struct tracefs_inode *ti = get_tracefs(inode);
+ struct inode *root_inode = ti->private;
+
+ /*
+ * If this inode has never been referenced, then update
+ * the permissions to the superblock.
+ */
+ if (!(ti->flags & TRACEFS_UID_PERM_SET))
+ inode->i_uid = root_inode->i_uid;
+
+ if (!(ti->flags & TRACEFS_GID_PERM_SET))
+ inode->i_gid = root_inode->i_gid;
+}
+
+static int tracefs_permission(struct mnt_idmap *idmap,
+ struct inode *inode, int mask)
+{
+ set_tracefs_inode_owner(inode);
+ return generic_permission(idmap, inode, mask);
+}
+
+static int tracefs_getattr(struct mnt_idmap *idmap,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ struct inode *inode = d_backing_inode(path->dentry);
+
+ set_tracefs_inode_owner(inode);
+ generic_fillattr(idmap, request_mask, inode, stat);
+ return 0;
+}
+
+static int tracefs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct iattr *attr)
+{
+ unsigned int ia_valid = attr->ia_valid;
+ struct inode *inode = d_inode(dentry);
+ struct tracefs_inode *ti = get_tracefs(inode);
+
+ if (ia_valid & ATTR_UID)
+ ti->flags |= TRACEFS_UID_PERM_SET;
+
+ if (ia_valid & ATTR_GID)
+ ti->flags |= TRACEFS_GID_PERM_SET;
+
+ return simple_setattr(idmap, dentry, attr);
+}
+
+static const struct inode_operations tracefs_instance_dir_inode_operations = {
.lookup = simple_lookup,
.mkdir = tracefs_syscall_mkdir,
.rmdir = tracefs_syscall_rmdir,
+ .permission = tracefs_permission,
+ .getattr = tracefs_getattr,
+ .setattr = tracefs_setattr,
+};
+
+static const struct inode_operations tracefs_dir_inode_operations = {
+ .lookup = simple_lookup,
+ .permission = tracefs_permission,
+ .getattr = tracefs_getattr,
+ .setattr = tracefs_setattr,
+};
+
+static const struct inode_operations tracefs_file_inode_operations = {
+ .permission = tracefs_permission,
+ .getattr = tracefs_getattr,
+ .setattr = tracefs_setattr,
};
struct inode *tracefs_get_inode(struct super_block *sb)
@@ -183,87 +259,6 @@ struct tracefs_fs_info {
struct tracefs_mount_opts mount_opts;
};
-static void change_gid(struct dentry *dentry, kgid_t gid)
-{
- if (!dentry->d_inode)
- return;
- dentry->d_inode->i_gid = gid;
-}
-
-/*
- * Taken from d_walk, but without he need for handling renames.
- * Nothing can be renamed while walking the list, as tracefs
- * does not support renames. This is only called when mounting
- * or remounting the file system, to set all the files to
- * the given gid.
- */
-static void set_gid(struct dentry *parent, kgid_t gid)
-{
- struct dentry *this_parent;
- struct list_head *next;
-
- this_parent = parent;
- spin_lock(&this_parent->d_lock);
-
- change_gid(this_parent, gid);
-repeat:
- next = this_parent->d_subdirs.next;
-resume:
- while (next != &this_parent->d_subdirs) {
- struct tracefs_inode *ti;
- struct list_head *tmp = next;
- struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
- next = tmp->next;
-
- /* Note, getdents() can add a cursor dentry with no inode */
- if (!dentry->d_inode)
- continue;
-
- spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
-
- change_gid(dentry, gid);
-
- /* If this is the events directory, update that too */
- ti = get_tracefs(dentry->d_inode);
- if (ti && (ti->flags & TRACEFS_EVENT_INODE))
- eventfs_update_gid(dentry, gid);
-
- if (!list_empty(&dentry->d_subdirs)) {
- spin_unlock(&this_parent->d_lock);
- spin_release(&dentry->d_lock.dep_map, _RET_IP_);
- this_parent = dentry;
- spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
- goto repeat;
- }
- spin_unlock(&dentry->d_lock);
- }
- /*
- * All done at this level ... ascend and resume the search.
- */
- rcu_read_lock();
-ascend:
- if (this_parent != parent) {
- struct dentry *child = this_parent;
- this_parent = child->d_parent;
-
- spin_unlock(&child->d_lock);
- spin_lock(&this_parent->d_lock);
-
- /* go into the first sibling still alive */
- do {
- next = child->d_child.next;
- if (next == &this_parent->d_subdirs)
- goto ascend;
- child = list_entry(next, struct dentry, d_child);
- } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));
- rcu_read_unlock();
- goto resume;
- }
- rcu_read_unlock();
- spin_unlock(&this_parent->d_lock);
- return;
-}
-
static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts)
{
substring_t args[MAX_OPT_ARGS];
@@ -336,10 +331,8 @@ static int tracefs_apply_options(struct super_block *sb, bool remount)
if (!remount || opts->opts & BIT(Opt_uid))
inode->i_uid = opts->uid;
- if (!remount || opts->opts & BIT(Opt_gid)) {
- /* Set all the group ids to the mount option */
- set_gid(sb->s_root, opts->gid);
- }
+ if (!remount || opts->opts & BIT(Opt_gid))
+ inode->i_gid = opts->gid;
return 0;
}
@@ -573,6 +566,26 @@ struct dentry *eventfs_end_creating(struct dentry *dentry)
return dentry;
}
+/* Find the inode that this will use for default */
+static struct inode *instance_inode(struct dentry *parent, struct inode *inode)
+{
+ struct tracefs_inode *ti;
+
+ /* If parent is NULL then use root inode */
+ if (!parent)
+ return d_inode(inode->i_sb->s_root);
+
+ /* Find the inode that is flagged as an instance or the root inode */
+ while (!IS_ROOT(parent)) {
+ ti = get_tracefs(d_inode(parent));
+ if (ti->flags & TRACEFS_INSTANCE_INODE)
+ break;
+ parent = parent->d_parent;
+ }
+
+ return d_inode(parent);
+}
+
/**
* tracefs_create_file - create a file in the tracefs filesystem
* @name: a pointer to a string containing the name of the file to create.
@@ -603,6 +616,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
+ struct tracefs_inode *ti;
struct dentry *dentry;
struct inode *inode;
@@ -621,7 +635,11 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
if (unlikely(!inode))
return tracefs_failed_creating(dentry);
+ ti = get_tracefs(inode);
+ ti->private = instance_inode(parent, inode);
+
inode->i_mode = mode;
+ inode->i_op = &tracefs_file_inode_operations;
inode->i_fop = fops ? fops : &tracefs_file_operations;
inode->i_private = data;
inode->i_uid = d_inode(dentry->d_parent)->i_uid;
@@ -634,6 +652,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
static struct dentry *__create_dir(const char *name, struct dentry *parent,
const struct inode_operations *ops)
{
+ struct tracefs_inode *ti;
struct dentry *dentry = tracefs_start_creating(name, parent);
struct inode *inode;
@@ -651,6 +670,9 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent,
inode->i_uid = d_inode(dentry->d_parent)->i_uid;
inode->i_gid = d_inode(dentry->d_parent)->i_gid;
+ ti = get_tracefs(inode);
+ ti->private = instance_inode(parent, inode);
+
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
d_instantiate(dentry, inode);
@@ -681,7 +703,7 @@ struct dentry *tracefs_create_dir(const char *name, struct dentry *parent)
if (security_locked_down(LOCKDOWN_TRACEFS))
return NULL;
- return __create_dir(name, parent, &simple_dir_inode_operations);
+ return __create_dir(name, parent, &tracefs_dir_inode_operations);
}
/**
@@ -712,7 +734,7 @@ __init struct dentry *tracefs_create_instance_dir(const char *name,
if (WARN_ON(tracefs_ops.mkdir || tracefs_ops.rmdir))
return NULL;
- dentry = __create_dir(name, parent, &tracefs_dir_inode_operations);
+ dentry = __create_dir(name, parent, &tracefs_instance_dir_inode_operations);
if (!dentry)
return NULL;
@@ -5,6 +5,9 @@
enum {
TRACEFS_EVENT_INODE = BIT(1),
TRACEFS_EVENT_TOP_INODE = BIT(2),
+ TRACEFS_GID_PERM_SET = BIT(3),
+ TRACEFS_UID_PERM_SET = BIT(4),
+ TRACEFS_INSTANCE_INODE = BIT(5),
};
struct tracefs_inode {