From: Waiman Long <Waiman.Long@hpe.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
Jan Kara <jack@suse.com>, Jeff Layton <jlayton@poochiereds.net>,
"J. Bruce Fields" <bfields@fieldses.org>,
Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Andi Kleen <andi@firstfloor.org>,
Dave Chinner <dchinner@redhat.com>,
Boqun Feng <boqun.feng@gmail.com>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>, Jan Kara <jack@suse.cz>,
Waiman Long <Waiman.Long@hpe.com>
Subject: [RESEND PATCH 3/5] fsnotify: Simplify inode iteration on umount
Date: Tue, 7 Jun 2016 15:35:53 -0400 [thread overview]
Message-ID: <1465328155-56754-4-git-send-email-Waiman.Long@hpe.com> (raw)
In-Reply-To: <1465328155-56754-1-git-send-email-Waiman.Long@hpe.com>
From: Jan Kara <jack@suse.cz>
fsnotify_unmount_inodes() played complex tricks to pin next inode in the
sb->s_inodes list when iterating over all inodes. If we switch to
keeping current inode pinned somewhat longer, we can make the code much
simpler and standard.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
---
fs/notify/inode_mark.c | 45 +++++++++------------------------------------
1 files changed, 9 insertions(+), 36 deletions(-)
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 741077d..a364524 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -150,12 +150,10 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
*/
void fsnotify_unmount_inodes(struct super_block *sb)
{
- struct inode *inode, *next_i, *need_iput = NULL;
+ struct inode *inode, *iput_inode = NULL;
spin_lock(&sb->s_inode_list_lock);
- list_for_each_entry_safe(inode, next_i, &sb->s_inodes, i_sb_list) {
- struct inode *need_iput_tmp;
-
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
/*
* We cannot __iget() an inode in state I_FREEING,
* I_WILL_FREE, or I_NEW which is fine because by that point
@@ -178,49 +176,24 @@ void fsnotify_unmount_inodes(struct super_block *sb)
continue;
}
- need_iput_tmp = need_iput;
- need_iput = NULL;
-
- /* In case fsnotify_inode_delete() drops a reference. */
- if (inode != need_iput_tmp)
- __iget(inode);
- else
- need_iput_tmp = NULL;
+ __iget(inode);
spin_unlock(&inode->i_lock);
-
- /* In case the dropping of a reference would nuke next_i. */
- while (&next_i->i_sb_list != &sb->s_inodes) {
- spin_lock(&next_i->i_lock);
- if (!(next_i->i_state & (I_FREEING | I_WILL_FREE)) &&
- atomic_read(&next_i->i_count)) {
- __iget(next_i);
- need_iput = next_i;
- spin_unlock(&next_i->i_lock);
- break;
- }
- spin_unlock(&next_i->i_lock);
- next_i = list_next_entry(next_i, i_sb_list);
- }
-
- /*
- * We can safely drop s_inode_list_lock here because either
- * we actually hold references on both inode and next_i or
- * end of list. Also no new inodes will be added since the
- * umount has begun.
- */
spin_unlock(&sb->s_inode_list_lock);
- if (need_iput_tmp)
- iput(need_iput_tmp);
+ if (iput_inode)
+ iput(iput_inode);
/* for each watch, send FS_UNMOUNT and then remove it */
fsnotify(inode, FS_UNMOUNT, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
fsnotify_inode_delete(inode);
- iput(inode);
+ iput_inode = inode;
spin_lock(&sb->s_inode_list_lock);
}
spin_unlock(&sb->s_inode_list_lock);
+
+ if (iput_inode)
+ iput(iput_inode);
}
--
1.7.1
next prev parent reply other threads:[~2016-06-07 19:37 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-07 19:35 [RESEND PATCH 0/5] vfs: Use dlock list for SB's s_inodes list Waiman Long
2016-06-07 19:35 ` [RESEND PATCH 1/5] lib/dlock-list: Distributed and lock-protected lists Waiman Long
2016-06-07 20:13 ` Andi Kleen
2016-06-07 23:53 ` Waiman Long
2016-07-11 17:37 ` Waiman Long
2016-06-07 19:35 ` [RESEND PATCH 2/5] lib/dlock-list: Add __percpu modifier for parameters Waiman Long
2016-06-07 19:35 ` Waiman Long [this message]
2016-06-07 19:35 ` [RESEND PATCH 4/5] vfs: Remove unnecessary list_for_each_entry_safe() variants Waiman Long
2016-06-07 19:35 ` [RESEND PATCH 5/5] vfs: Use dlock list for superblock's inode list Waiman Long
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1465328155-56754-4-git-send-email-Waiman.Long@hpe.com \
--to=waiman.long@hpe.com \
--cc=andi@firstfloor.org \
--cc=bfields@fieldses.org \
--cc=boqun.feng@gmail.com \
--cc=cl@linux-foundation.org \
--cc=dchinner@redhat.com \
--cc=doug.hatch@hpe.com \
--cc=jack@suse.com \
--cc=jack@suse.cz \
--cc=jlayton@poochiereds.net \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=scott.norton@hpe.com \
--cc=tj@kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).