From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752983AbdFNQM1 (ORCPT ); Wed, 14 Jun 2017 12:12:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:47600 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752445AbdFNQMY (ORCPT ); Wed, 14 Jun 2017 12:12:24 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED35B235E1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=shli@fb.com From: Shaohua Li To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Cc: tj@kernel.org, gregkh@linuxfoundation.org, hch@lst.de, axboe@fb.com, rostedt@goodmis.org, lizefan@huawei.com, Kernel-team@fb.com, Shaohua Li Subject: [PATCH V2 05/12] kernfs: introduce kernfs_node_id Date: Wed, 14 Jun 2017 09:12:03 -0700 Message-Id: X-Mailer: git-send-email 2.11.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shaohua Li inode number and generation can identify a kernfs node. We are going to export the identification by exportfs operations, so put ino and generation into a separate structure. It's convenient when later patches use the identification. Please note, I extend inode number to 64 bits. idr actually doesn't support 64-bit yet, so currently inode number is always 32-bit. Tejun has concerns 32-bit inode and generation could wrap. We will need to fix this later. The data structure will be exported out to userspace, so the goal of the 64-bit data structure is to avoid change the data structure if we make inode number to 64-bit later. Signed-off-by: Shaohua Li --- fs/kernfs/dir.c | 10 +++++----- fs/kernfs/file.c | 4 ++-- fs/kernfs/inode.c | 4 ++-- include/linux/cgroup.h | 2 +- include/linux/kernfs.h | 9 +++++++-- 5 files changed, 17 insertions(+), 12 deletions(-) diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index e54fdd9..7483bea 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -539,7 +539,7 @@ void kernfs_put(struct kernfs_node *kn) } kfree(kn->iattr); spin_lock(&kernfs_idr_lock); - idr_remove(&root->ino_idr, kn->ino); + idr_remove(&root->ino_idr, kn->id.ino); spin_unlock(&kernfs_idr_lock); kmem_cache_free(kernfs_node_cache, kn); @@ -639,8 +639,8 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, idr_preload_end(); if (ret < 0) goto err_out2; - kn->ino = ret; - kn->generation = atomic_inc_return(&root->next_generation); + kn->id.ino = ret; + kn->id.generation = atomic_inc_return(&root->next_generation); /* set ino first. Above atomic_inc_return has a barrier */ atomic_set(&kn->count, 1); @@ -711,7 +711,7 @@ struct kernfs_node *kernfs_find_and_get_node_by_ino(struct kernfs_root *root, * 'ino' should be uptodate, hence we can use 'ino' to filter stale * node. */ - if (kn->ino != ino) + if (kn->id.ino != ino) goto out; rcu_read_unlock(); @@ -1644,7 +1644,7 @@ static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) const char *name = pos->name; unsigned int type = dt_type(pos); int len = strlen(name); - ino_t ino = pos->ino; + ino_t ino = pos->id.ino; ctx->pos = pos->hash; file->private_data = pos; diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 7f90d4d..7441925 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -895,7 +895,7 @@ static void kernfs_notify_workfn(struct work_struct *work) * have the matching @file available. Look up the inodes * and generate the events manually. */ - inode = ilookup(info->sb, kn->ino); + inode = ilookup(info->sb, kn->id.ino); if (!inode) continue; @@ -903,7 +903,7 @@ static void kernfs_notify_workfn(struct work_struct *work) if (parent) { struct inode *p_inode; - p_inode = ilookup(info->sb, parent->ino); + p_inode = ilookup(info->sb, parent->id.ino); if (p_inode) { fsnotify(p_inode, FS_MODIFY | FS_EVENT_ON_CHILD, inode, FSNOTIFY_EVENT_INODE, kn->name, 0); diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index 4c8b510..a343039 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -220,7 +220,7 @@ static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode) inode->i_private = kn; inode->i_mapping->a_ops = &kernfs_aops; inode->i_op = &kernfs_iops; - inode->i_generation = kn->generation; + inode->i_generation = kn->id.generation; set_default_inode_attr(inode, kn->mode); kernfs_refresh_inode(kn, inode); @@ -266,7 +266,7 @@ struct inode *kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn) { struct inode *inode; - inode = iget_locked(sb, kn->ino); + inode = iget_locked(sb, kn->id.ino); if (inode && (inode->i_state & I_NEW)) kernfs_init_inode(kn, inode); diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 710a005..30c6877 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -543,7 +543,7 @@ static inline bool cgroup_is_populated(struct cgroup *cgrp) /* returns ino associated with a cgroup */ static inline ino_t cgroup_ino(struct cgroup *cgrp) { - return cgrp->kn->ino; + return cgrp->kn->id.ino; } /* cft/css accessors for cftype->write() operation */ diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 61668d1..6be2d57 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -95,6 +95,12 @@ struct kernfs_elem_attr { struct kernfs_node *notify_next; /* for kernfs_notify() */ }; +/* represent a kernfs node */ +struct kernfs_node_id { + u64 ino; + u32 generation; +} __attribute__((packed)); + /* * kernfs_node - the building block of kernfs hierarchy. Each and every * kernfs node is represented by single kernfs_node. Most fields are @@ -131,11 +137,10 @@ struct kernfs_node { void *priv; + struct kernfs_node_id id; unsigned short flags; umode_t mode; - unsigned int ino; struct kernfs_iattrs *iattr; - u32 generation; }; /* -- 2.9.3