From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 541C5196D90; Thu, 6 Jun 2024 14:21:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683667; cv=none; b=owpv7PSx33O14CrrSXWCim6yrRh2BxvEd0HjV4pJnMrai6t/tvmX0cdSj4KUvLmdQtZMAwUe/st7l51uC8sfMqGwLwwNIbXPqGYvVhUTgMtVyZolyWnmKbNSMHCTAxjMCXT+s5CBtzB9jhBNhepZCffGr5cHslLjMtoReU0vQo8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683667; c=relaxed/simple; bh=hW9t5STaZj9wdX+JzmK5zosJGo7lEpDnDV2uVWy4qAI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aGpU01VqNEyiCcb0w0O17UZSfwnta9Tg0uGEs2j2iMXVF76Uh+Gf5C3P6y+WvvvoiRGqzqNjM5wsIh8U5SHT/sk2dQgAZdNwMPyzNJkxj016xTbFM1yJiM1bGxliVhMdmL/VmftNmlWC7wK2S6g1jjvQgu2B+FPWfPDTRmEMe1Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KcXutyEd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KcXutyEd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34E8DC2BD10; Thu, 6 Jun 2024 14:21:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1717683667; bh=hW9t5STaZj9wdX+JzmK5zosJGo7lEpDnDV2uVWy4qAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KcXutyEdp1uJPk4wtarHvetY2+SPIFU/xXfE6iv2ReM+g46NvWxdWu+xnaVNk5VYX 7f74RpwM3stStFRSnqbb9yDr+FDHX0aFMm9oZYaDVn8lhSpRLvCAtdHqnn9ovk9jUO 0uP+WY8ELcG84D4t5H72RMWwKLST8Gi+eekKO7+s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Linus Torvalds , Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Christian Brauner , Al Viro , Ajay Kaher , "Steven Rostedt (Google)" , Sasha Levin Subject: [PATCH 6.6 553/744] eventfs: Create eventfs_root_inode to store dentry Date: Thu, 6 Jun 2024 16:03:45 +0200 Message-ID: <20240606131750.194303597@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240606131732.440653204@linuxfoundation.org> References: <20240606131732.440653204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt (Google) [ Upstream commit c3137ab6318d56370dd5541ebf027ddfc0c8557c ] Only the root "events" directory stores a dentry. There's no reason to hold a dentry pointer for every eventfs_inode as it is never set except for the root "events" eventfs_inode. Create a eventfs_root_inode structure that holds the events_dir dentry. The "events" eventfs_inode *is* special, let it have its own descriptor. Link: https://lore.kernel.org/linux-trace-kernel/20240201161617.658992558@goodmis.org Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Christian Brauner Cc: Al Viro Cc: Ajay Kaher Signed-off-by: Steven Rostedt (Google) Stable-dep-of: b63db58e2fa5 ("eventfs/tracing: Add callback for release of an eventfs_inode") Signed-off-by: Sasha Levin --- fs/tracefs/event_inode.c | 65 +++++++++++++++++++++++++++++++++------- fs/tracefs/internal.h | 2 -- 2 files changed, 55 insertions(+), 12 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 47228de4c17af..6d3a11b0c606a 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -35,6 +35,17 @@ static DEFINE_MUTEX(eventfs_mutex); /* Choose something "unique" ;-) */ #define EVENTFS_FILE_INODE_INO 0x12c4e37 +struct eventfs_root_inode { + struct eventfs_inode ei; + struct dentry *events_dir; +}; + +static struct eventfs_root_inode *get_root_inode(struct eventfs_inode *ei) +{ + WARN_ON_ONCE(!ei->is_events); + return container_of(ei, struct eventfs_root_inode, ei); +} + /* Just try to make something consistent and unique */ static int eventfs_dir_ino(struct eventfs_inode *ei) { @@ -72,12 +83,18 @@ enum { static void release_ei(struct kref *ref) { struct eventfs_inode *ei = container_of(ref, struct eventfs_inode, kref); + struct eventfs_root_inode *rei; WARN_ON_ONCE(!ei->is_freed); kfree(ei->entry_attrs); kfree_const(ei->name); - kfree_rcu(ei, rcu); + if (ei->is_events) { + rei = get_root_inode(ei); + kfree_rcu(rei, ei.rcu); + } else { + kfree_rcu(ei, rcu); + } } static inline void put_ei(struct eventfs_inode *ei) @@ -418,19 +435,43 @@ static struct dentry *lookup_dir_entry(struct dentry *dentry, return NULL; } +static inline struct eventfs_inode *init_ei(struct eventfs_inode *ei, const char *name) +{ + ei->name = kstrdup_const(name, GFP_KERNEL); + if (!ei->name) + return NULL; + kref_init(&ei->kref); + return ei; +} + static inline struct eventfs_inode *alloc_ei(const char *name) { struct eventfs_inode *ei = kzalloc(sizeof(*ei), GFP_KERNEL); + struct eventfs_inode *result; if (!ei) return NULL; - ei->name = kstrdup_const(name, GFP_KERNEL); - if (!ei->name) { + result = init_ei(ei, name); + if (!result) kfree(ei); + + return result; +} + +static inline struct eventfs_inode *alloc_root_ei(const char *name) +{ + struct eventfs_root_inode *rei = kzalloc(sizeof(*rei), GFP_KERNEL); + struct eventfs_inode *ei; + + if (!rei) return NULL; - } - kref_init(&ei->kref); + + rei->ei.is_events = 1; + ei = init_ei(&rei->ei, name); + if (!ei) + kfree(rei); + return ei; } @@ -719,6 +760,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry int size, void *data) { struct dentry *dentry = tracefs_start_creating(name, parent); + struct eventfs_root_inode *rei; struct eventfs_inode *ei; struct tracefs_inode *ti; struct inode *inode; @@ -731,7 +773,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry if (IS_ERR(dentry)) return ERR_CAST(dentry); - ei = alloc_ei(name); + ei = alloc_root_ei(name); if (!ei) goto fail; @@ -740,10 +782,11 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry goto fail; // Note: we have a ref to the dentry from tracefs_start_creating() - ei->events_dir = dentry; + rei = get_root_inode(ei); + rei->events_dir = dentry; + ei->entries = entries; ei->nr_entries = size; - ei->is_events = 1; ei->data = data; /* Save the ownership of this directory */ @@ -846,13 +889,15 @@ void eventfs_remove_dir(struct eventfs_inode *ei) */ void eventfs_remove_events_dir(struct eventfs_inode *ei) { + struct eventfs_root_inode *rei; struct dentry *dentry; - dentry = ei->events_dir; + rei = get_root_inode(ei); + dentry = rei->events_dir; if (!dentry) return; - ei->events_dir = NULL; + rei->events_dir = NULL; eventfs_remove_dir(ei); /* diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index b79ab2827b504..f704d8348357e 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -39,7 +39,6 @@ struct eventfs_attr { * @children: link list into the child eventfs_inode * @entries: the array of entries representing the files in the directory * @name: the name of the directory to create - * @events_dir: the dentry of the events directory * @entry_attrs: Saved mode and ownership of the @d_children * @data: The private data to pass to the callbacks * @attr: Saved mode and ownership of eventfs_inode itself @@ -57,7 +56,6 @@ struct eventfs_inode { struct list_head children; const struct eventfs_entry *entries; const char *name; - struct dentry *events_dir; struct eventfs_attr *entry_attrs; void *data; struct eventfs_attr attr; -- 2.43.0