lkml.org 
[lkml]   [2020]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH v2 3/6] proc: In proc_prune_siblings_dcache cache an aquired super block

Because there are likely to be several sysctls in a row on the
same superblock cache the super_block after the count has
been raised and don't deactivate it until we are processing
another super_block.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
fs/proc/inode.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 74ce4a8d05eb..fa2dc732cd77 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -108,10 +108,11 @@ void proc_prune_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock)
struct inode *inode;
struct proc_inode *ei;
struct hlist_node *node;
- struct super_block *sb;
+ struct super_block *old_sb = NULL;

rcu_read_lock();
for (;;) {
+ struct super_block *sb;
node = hlist_first_rcu(inodes);
if (!node)
break;
@@ -122,23 +123,28 @@ void proc_prune_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock)

inode = &ei->vfs_inode;
sb = inode->i_sb;
- if (!atomic_inc_not_zero(&sb->s_active))
+ if ((sb != old_sb) && !atomic_inc_not_zero(&sb->s_active))
continue;
inode = igrab(inode);
rcu_read_unlock();
+ if (sb != old_sb) {
+ if (old_sb)
+ deactivate_super(old_sb);
+ old_sb = sb;
+ }
if (unlikely(!inode)) {
- deactivate_super(sb);
rcu_read_lock();
continue;
}

d_prune_aliases(inode);
iput(inode);
- deactivate_super(sb);

rcu_read_lock();
}
rcu_read_unlock();
+ if (old_sb)
+ deactivate_super(old_sb);
}

static int proc_show_options(struct seq_file *seq, struct dentry *root)
--
2.25.0
\
 
 \ /
  Last update: 2020-02-24 17:30    [W:0.206 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site