iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

proc: In proc_prune_siblings_dcache cache an aquired super block

Browse Source 
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>
This commit is contained in:
Eric W. Biederman 2020-02-21 08:33:57 -06:00
parent 26dbc60f38
commit 080f6276fc
1 changed files with 10 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
fs/proc/inode.c
View File

@ -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)