diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 0256afdd4acf..5d88c184f0fc 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -37,7 +37,6 @@ static DEFINE_MUTEX(eventfs_mutex); struct eventfs_root_inode { struct eventfs_inode ei; - struct inode *parent_inode; struct dentry *events_dir; }; @@ -50,8 +49,12 @@ static struct eventfs_root_inode *get_root_inode(struct eventfs_inode *ei) /* Just try to make something consistent and unique */ static int eventfs_dir_ino(struct eventfs_inode *ei) { - if (!ei->ino) + if (!ei->ino) { ei->ino = get_next_ino(); + /* Must not have the file inode number */ + if (ei->ino == EVENTFS_FILE_INODE_INO) + ei->ino = get_next_ino(); + } return ei->ino; } @@ -207,7 +210,9 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, * determined by the parent directory. */ if (dentry->d_inode->i_mode & S_IFDIR) { - update_attr(&ei->attr, iattr); + /* Just use the inode permissions for the events directory */ + if (!ei->is_events) + update_attr(&ei->attr, iattr); } else { name = dentry->d_name.name; @@ -225,70 +230,9 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, return ret; } -static void update_events_attr(struct eventfs_inode *ei, struct super_block *sb) -{ - struct eventfs_root_inode *rei; - struct inode *parent; - - rei = get_root_inode(ei); - - /* Use the parent inode permissions unless root set its permissions */ - parent = rei->parent_inode; - - if (rei->ei.attr.mode & EVENTFS_SAVE_UID) - ei->attr.uid = rei->ei.attr.uid; - else - ei->attr.uid = parent->i_uid; - - if (rei->ei.attr.mode & EVENTFS_SAVE_GID) - ei->attr.gid = rei->ei.attr.gid; - else - ei->attr.gid = parent->i_gid; -} - -static void set_top_events_ownership(struct inode *inode) -{ - struct tracefs_inode *ti = get_tracefs(inode); - struct eventfs_inode *ei = ti->private; - - /* The top events directory doesn't get automatically updated */ - if (!ei || !ei->is_events) - return; - - update_events_attr(ei, inode->i_sb); - - 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_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 = { @@ -301,6 +245,45 @@ static const struct file_operations eventfs_file_operations = { .llseek = generic_file_llseek, }; +static void eventfs_set_attrs(struct eventfs_inode *ei, bool update_uid, kuid_t uid, + bool update_gid, kgid_t gid, int level) +{ + struct eventfs_inode *ei_child; + + /* Update events// */ + if (WARN_ON_ONCE(level > 3)) + return; + + if (update_uid) { + ei->attr.mode &= ~EVENTFS_SAVE_UID; + ei->attr.uid = uid; + } + + if (update_gid) { + ei->attr.mode &= ~EVENTFS_SAVE_GID; + ei->attr.gid = gid; + } + + list_for_each_entry(ei_child, &ei->children, list) { + eventfs_set_attrs(ei_child, update_uid, uid, update_gid, gid, level + 1); + } + + if (!ei->entry_attrs) + return; + + for (int i = 0; i < ei->nr_entries; i++) { + if (update_uid) { + ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_UID; + ei->entry_attrs[i].uid = uid; + } + if (update_gid) { + ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_GID; + ei->entry_attrs[i].gid = gid; + } + } + +} + /* * On a remount of tracefs, if UID or GID options are set, then * the mount point inode permissions should be used. @@ -310,75 +293,61 @@ void eventfs_remount(struct tracefs_inode *ti, bool update_uid, bool update_gid) { struct eventfs_inode *ei = ti->private; - if (!ei) + /* Only the events directory does the updates */ + if (!ei || !ei->is_events || ei->is_freed) return; - if (update_uid) - ei->attr.mode &= ~EVENTFS_SAVE_UID; - - if (update_gid) - ei->attr.mode &= ~EVENTFS_SAVE_GID; - - if (!ei->entry_attrs) - return; - - for (int i = 0; i < ei->nr_entries; i++) { - if (update_uid) - ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_UID; - if (update_gid) - ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_GID; - } + eventfs_set_attrs(ei, update_uid, ti->vfs_inode.i_uid, + update_gid, ti->vfs_inode.i_gid, 0); } -/* Return the evenfs_inode of the "events" directory */ -static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) +static void update_inode_attr(struct inode *inode, umode_t mode, + struct eventfs_attr *attr, struct eventfs_root_inode *rei) { - struct eventfs_inode *ei; - - do { - // The parent is stable because we do not do renames - dentry = dentry->d_parent; - // ... and directories always have d_fsdata - ei = dentry->d_fsdata; - - /* - * If the ei is being freed, the ownership of the children - * doesn't matter. - */ - if (ei->is_freed) - return NULL; - - // Walk upwards until you find the events inode - } while (!ei->is_events); - - update_events_attr(ei, dentry->d_sb); - - return ei; -} - -static void update_inode_attr(struct dentry *dentry, struct inode *inode, - struct eventfs_attr *attr, umode_t mode) -{ - struct eventfs_inode *events_ei = eventfs_find_events(dentry); - - if (!events_ei) - return; - - inode->i_mode = mode; - inode->i_uid = events_ei->attr.uid; - inode->i_gid = events_ei->attr.gid; - - if (!attr) - return; - - if (attr->mode & EVENTFS_SAVE_MODE) + if (attr && attr->mode & EVENTFS_SAVE_MODE) inode->i_mode = attr->mode & EVENTFS_MODE_MASK; + else + inode->i_mode = mode; - if (attr->mode & EVENTFS_SAVE_UID) + if (attr && attr->mode & EVENTFS_SAVE_UID) inode->i_uid = attr->uid; + else + inode->i_uid = rei->ei.attr.uid; - if (attr->mode & EVENTFS_SAVE_GID) + if (attr && attr->mode & EVENTFS_SAVE_GID) inode->i_gid = attr->gid; + else + inode->i_gid = rei->ei.attr.gid; +} + +static struct inode *eventfs_get_inode(struct dentry *dentry, struct eventfs_attr *attr, + umode_t mode, struct eventfs_inode *ei) +{ + struct eventfs_root_inode *rei; + struct eventfs_inode *pei; + struct tracefs_inode *ti; + struct inode *inode; + + inode = tracefs_get_inode(dentry->d_sb); + if (!inode) + return NULL; + + ti = get_tracefs(inode); + ti->private = ei; + ti->flags |= TRACEFS_EVENT_INODE; + + /* Find the top dentry that holds the "events" directory */ + do { + dentry = dentry->d_parent; + /* Directories always have d_fsdata */ + pei = dentry->d_fsdata; + } while (!pei->is_events); + + rei = get_root_inode(pei); + + update_inode_attr(inode, mode, attr, rei); + + return inode; } /** @@ -401,7 +370,6 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei, void *data, const struct file_operations *fop) { - struct tracefs_inode *ti; struct inode *inode; if (!(mode & S_IFMT)) @@ -410,13 +378,11 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei, if (WARN_ON_ONCE(!S_ISREG(mode))) return ERR_PTR(-EIO); - inode = tracefs_get_inode(dentry->d_sb); + /* Only directories have ti->private set to an ei, not files */ + inode = eventfs_get_inode(dentry, attr, mode, NULL); if (unlikely(!inode)) return ERR_PTR(-ENOMEM); - /* If the user updated the directory's attributes, use them */ - update_inode_attr(dentry, inode, attr, mode); - inode->i_op = &eventfs_file_inode_operations; inode->i_fop = fop; inode->i_private = data; @@ -424,9 +390,6 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei, /* All files will have the same inode number */ inode->i_ino = EVENTFS_FILE_INODE_INO; - ti = get_tracefs(inode); - ti->flags |= TRACEFS_EVENT_INODE; - // Files have their parent's ei as their fsdata dentry->d_fsdata = get_ei(parent_ei); @@ -446,28 +409,19 @@ static struct dentry *lookup_file(struct eventfs_inode *parent_ei, static struct dentry *lookup_dir_entry(struct dentry *dentry, struct eventfs_inode *pei, struct eventfs_inode *ei) { - struct tracefs_inode *ti; struct inode *inode; + umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; - inode = tracefs_get_inode(dentry->d_sb); + inode = eventfs_get_inode(dentry, &ei->attr, mode, ei); if (unlikely(!inode)) return ERR_PTR(-ENOMEM); - /* If the user updated the directory's attributes, use them */ - update_inode_attr(dentry, inode, &ei->attr, - S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); - inode->i_op = &eventfs_dir_inode_operations; inode->i_fop = &eventfs_file_operations; /* All directories will have the same inode number */ inode->i_ino = eventfs_dir_ino(ei); - ti = get_tracefs(inode); - ti->flags |= TRACEFS_EVENT_INODE; - /* Only directories have ti->private set to an ei, not files */ - ti->private = ei; - dentry->d_fsdata = get_ei(ei); d_add(dentry, inode); @@ -828,7 +782,6 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry // Note: we have a ref to the dentry from tracefs_start_creating() rei = get_root_inode(ei); rei->events_dir = dentry; - rei->parent_inode = d_inode(dentry->d_sb->s_root); ei->entries = entries; ei->nr_entries = size; @@ -838,15 +791,13 @@ 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; + /* + * The ei->attr will be used as the default values for the + * files beneath this directory. + */ ei->attr.uid = uid; ei->attr.gid = gid; - /* - * When the "events" directory is created, it takes on the - * permissions of its parent. But can be reset on remount. - */ - ei->attr.mode |= EVENTFS_SAVE_UID | EVENTFS_SAVE_GID; - INIT_LIST_HEAD(&ei->children); INIT_LIST_HEAD(&ei->list); diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index a827f6a716c4..7c29f4afc23d 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -373,12 +373,21 @@ static int tracefs_apply_options(struct super_block *sb, bool remount) rcu_read_lock(); list_for_each_entry_rcu(ti, &tracefs_inodes, list) { - if (update_uid) + if (update_uid) { ti->flags &= ~TRACEFS_UID_PERM_SET; + ti->vfs_inode.i_uid = fsi->uid; + } - if (update_gid) + if (update_gid) { ti->flags &= ~TRACEFS_GID_PERM_SET; + ti->vfs_inode.i_gid = fsi->gid; + } + /* + * Note, the above ti->vfs_inode updates are + * used in eventfs_remount() so they must come + * before calling it. + */ if (ti->flags & TRACEFS_EVENT_INODE) eventfs_remount(ti, update_uid, update_gid); } @@ -417,10 +426,26 @@ static int tracefs_show_options(struct seq_file *m, struct dentry *root) return 0; } +static int tracefs_drop_inode(struct inode *inode) +{ + struct tracefs_inode *ti = get_tracefs(inode); + + /* + * This inode is being freed and cannot be used for + * eventfs. Clear the flag so that it doesn't call into + * eventfs during the remount flag updates. The eventfs_inode + * gets freed after an RCU cycle, so the content will still + * be safe if the iteration is going on now. + */ + ti->flags &= ~TRACEFS_EVENT_INODE; + + return 1; +} + static const struct super_operations tracefs_super_operations = { .alloc_inode = tracefs_alloc_inode, .free_inode = tracefs_free_inode, - .drop_inode = generic_delete_inode, + .drop_inode = tracefs_drop_inode, .statfs = simple_statfs, .show_options = tracefs_show_options, }; @@ -446,22 +471,7 @@ static int tracefs_d_revalidate(struct dentry *dentry, unsigned int flags) return !(ei && ei->is_freed); } -static void tracefs_d_iput(struct dentry *dentry, struct inode *inode) -{ - struct tracefs_inode *ti = get_tracefs(inode); - - /* - * This inode is being freed and cannot be used for - * eventfs. Clear the flag so that it doesn't call into - * eventfs during the remount flag updates. The eventfs_inode - * gets freed after an RCU cycle, so the content will still - * be safe if the iteration is going on now. - */ - ti->flags &= ~TRACEFS_EVENT_INODE; -} - static const struct dentry_operations tracefs_dentry_operations = { - .d_iput = tracefs_d_iput, .d_revalidate = tracefs_d_revalidate, .d_release = tracefs_d_release, };