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 0BE56296BAF for ; Thu, 9 Apr 2026 18:34:02 +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=1775759642; cv=none; b=JqC0E1P6StYKFS5OGniiH5tY732ABpDy01Fc24rh2fU96Uw2wXAmjt9lZf+TwItlg6Vih+TgtLESFblcQXpKOh3YbkUuTCSVStkrZ11jYAVSONluTLnJHm3KEN2M5Mo/C7GADMkgSo6S/OrOd/IOkEuAqSQV7PddsSICVnUGj/g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775759642; c=relaxed/simple; bh=rsFPmAnEQaN9n9f4V8aMdDmfyeQqxBv4dnKi76Z9Dbg=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=JU4/KWSho9eJrbvRV6/AfhhO1EiJ8DgGE84YWL3rMMLCUoLEEA1/l89fDBeqJ7Nuwge1/8lfsQEHfkkxRWWtGNke4+qGOLHZDKuELH+VeYAVphP7RQlb4bIS48eNgUyS6TSWdLslIHlMfuy9+VzqdK/59E7u+OjNUvXNeVt7hiU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VaaQ9xFi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VaaQ9xFi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDC76C4CEF7; Thu, 9 Apr 2026 18:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775759641; bh=rsFPmAnEQaN9n9f4V8aMdDmfyeQqxBv4dnKi76Z9Dbg=; h=Date:From:To:Cc:Subject:References:From; b=VaaQ9xFiltGXNvpj0/rFUE5nBMErJ6lfoojGtLdSeLPJLao35ROx7AcXV7pUuKJBZ j8mqPi53Y2Hq5sPqKJCZIXyOgjSErnjdgWrZkNLFnhnQA/Iowf3NLPjPKIvCHYUhhM Qn/jmfCRFSwtwh8wiJiFz02E4MFXZ0CFVwwy4oKGGcm0H+Ze01HSnVRsHXzgOz5yjs j8cb9J0gS+SoevDkIKSEc2l65Dgry5Qgqbl6Yu+5PsoLGEP/rAZZsnJ3SYJqVGa+8g ZHE8K/AQVHYUg7ggzPz2E4b9WeIVIvpxq8BGzpUGfYeWBmFyZI5aTbeY+6M3GViPPP K/77n++fEz2ug== Received: from rostedt by gandalf with local (Exim 4.99.1) (envelope-from ) id 1wAuDp-00000003pGF-0kzF; Thu, 09 Apr 2026 14:35:21 -0400 Message-ID: <20260409183521.038020583@kernel.org> User-Agent: quilt/0.69 Date: Thu, 09 Apr 2026 14:34:58 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton Subject: [for-next][PATCH 1/3] eventfs: Simplify code using guard()s References: <20260409183457.935983082@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Steven Rostedt Use guard(mutex), scoped_guard(mutex) and guard(src) to simplify the code and remove a lot of the jumps to "out:" labels. Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250604151625.250d13e1@gandalf.local.home Signed-off-by: Steven Rostedt (Google) Reviewed-by: Masami Hiramatsu (Google) --- fs/tracefs/event_inode.c | 96 +++++++++++++++------------------------- 1 file changed, 36 insertions(+), 60 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 8e5ac464b328..af8d05df2726 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -180,29 +180,25 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name; int ret; - mutex_lock(&eventfs_mutex); + guard(mutex)(&eventfs_mutex); ei = dentry->d_fsdata; - if (ei->is_freed) { - /* Do not allow changes if the event is about to be removed. */ - mutex_unlock(&eventfs_mutex); + /* Do not allow changes if the event is about to be removed. */ + if (ei->is_freed) return -ENODEV; - } /* Preallocate the children mode array if necessary */ if (!(dentry->d_inode->i_mode & S_IFDIR)) { if (!ei->entry_attrs) { ei->entry_attrs = kzalloc_objs(*ei->entry_attrs, ei->nr_entries, GFP_NOFS); - if (!ei->entry_attrs) { - ret = -ENOMEM; - goto out; - } + if (!ei->entry_attrs) + return -ENOMEM; } } ret = simple_setattr(idmap, dentry, iattr); if (ret < 0) - goto out; + return ret; /* * If this is a dir, then update the ei cache, only the file @@ -225,8 +221,6 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, } } } - out: - mutex_unlock(&eventfs_mutex); return ret; } @@ -528,26 +522,24 @@ static struct dentry *eventfs_root_lookup(struct inode *dir, struct tracefs_inode *ti; struct eventfs_inode *ei; const char *name = dentry->d_name.name; - struct dentry *result = NULL; ti = get_tracefs(dir); if (WARN_ON_ONCE(!(ti->flags & TRACEFS_EVENT_INODE))) return ERR_PTR(-EIO); - mutex_lock(&eventfs_mutex); + guard(mutex)(&eventfs_mutex); ei = ti->private; if (!ei || ei->is_freed) - goto out; + return NULL; list_for_each_entry(ei_child, &ei->children, list) { if (strcmp(ei_child->name, name) != 0) continue; /* A child is freed and removed from the list at the same time */ if (WARN_ON_ONCE(ei_child->is_freed)) - goto out; - result = lookup_dir_entry(dentry, ei, ei_child); - goto out; + return NULL; + return lookup_dir_entry(dentry, ei, ei_child); } for (int i = 0; i < ei->nr_entries; i++) { @@ -561,14 +553,12 @@ static struct dentry *eventfs_root_lookup(struct inode *dir, data = ei->data; if (entry->callback(name, &mode, &data, &fops) <= 0) - goto out; + return NULL; + + return lookup_file_dentry(dentry, ei, i, mode, data, fops); - result = lookup_file_dentry(dentry, ei, i, mode, data, fops); - goto out; } - out: - mutex_unlock(&eventfs_mutex); - return result; + return NULL; } /* @@ -584,7 +574,6 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx) struct eventfs_inode *ei; const char *name; umode_t mode; - int idx; int ret = -EINVAL; int ino; int i, r, c; @@ -598,16 +587,13 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx) c = ctx->pos - 2; - idx = srcu_read_lock(&eventfs_srcu); + guard(srcu)(&eventfs_srcu); - mutex_lock(&eventfs_mutex); - ei = READ_ONCE(ti->private); - if (ei && ei->is_freed) - ei = NULL; - mutex_unlock(&eventfs_mutex); - - if (!ei) - goto out; + scoped_guard(mutex, &eventfs_mutex) { + ei = READ_ONCE(ti->private); + if (!ei || ei->is_freed) + return -EINVAL; + } /* * Need to create the dentries and inodes to have a consistent @@ -622,21 +608,19 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx) entry = &ei->entries[i]; name = entry->name; - mutex_lock(&eventfs_mutex); /* If ei->is_freed then just bail here, nothing more to do */ - if (ei->is_freed) { - mutex_unlock(&eventfs_mutex); - goto out; + scoped_guard(mutex, &eventfs_mutex) { + if (ei->is_freed) + return -EINVAL; + r = entry->callback(name, &mode, &cdata, &fops); } - r = entry->callback(name, &mode, &cdata, &fops); - mutex_unlock(&eventfs_mutex); if (r <= 0) continue; ino = EVENTFS_FILE_INODE_INO; if (!dir_emit(ctx, name, strlen(name), ino, DT_REG)) - goto out; + return -EINVAL; } /* Subtract the skipped entries above */ @@ -659,19 +643,13 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx) ino = eventfs_dir_ino(ei_child); - if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR)) - goto out_dec; + if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR)) { + /* Incremented ctx->pos without adding something, reset it */ + ctx->pos--; + return -EINVAL; + } } - ret = 1; - out: - srcu_read_unlock(&eventfs_srcu, idx); - - return ret; - - out_dec: - /* Incremented ctx->pos without adding something, reset it */ - ctx->pos--; - goto out; + return 1; } /** @@ -728,11 +706,10 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode INIT_LIST_HEAD(&ei->children); INIT_LIST_HEAD(&ei->list); - mutex_lock(&eventfs_mutex); - if (!parent->is_freed) - list_add_tail(&ei->list, &parent->children); - mutex_unlock(&eventfs_mutex); - + scoped_guard(mutex, &eventfs_mutex) { + if (!parent->is_freed) + list_add_tail(&ei->list, &parent->children); + } /* Was the parent freed? */ if (list_empty(&ei->list)) { cleanup_ei(ei); @@ -878,9 +855,8 @@ void eventfs_remove_dir(struct eventfs_inode *ei) if (!ei) return; - mutex_lock(&eventfs_mutex); + guard(mutex)(&eventfs_mutex); eventfs_remove_rec(ei, 0); - mutex_unlock(&eventfs_mutex); } /** -- 2.51.0