From e914f8eb445e8f74b00303c19c2ffceaedd16a05 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 12 Oct 2016 01:30:33 -0300
Subject: Linux-libre 4.7.6-gnu
---
fs/autofs4/expire.c | 55 ++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 42 insertions(+), 13 deletions(-)
(limited to 'fs/autofs4')
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index b493909e7..d8e6d421c 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -417,6 +417,7 @@ static struct dentry *should_expire(struct dentry *dentry,
}
return NULL;
}
+
/*
* Find an eligible tree to time-out
* A tree is eligible if :-
@@ -432,6 +433,7 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
struct dentry *root = sb->s_root;
struct dentry *dentry;
struct dentry *expired;
+ struct dentry *found;
struct autofs_info *ino;
if (!root)
@@ -442,31 +444,46 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
dentry = NULL;
while ((dentry = get_next_positive_subdir(dentry, root))) {
+ int flags = how;
+
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
- if (ino->flags & AUTOFS_INF_WANT_EXPIRE)
- expired = NULL;
- else
- expired = should_expire(dentry, mnt, timeout, how);
- if (!expired) {
+ if (ino->flags & AUTOFS_INF_WANT_EXPIRE) {
spin_unlock(&sbi->fs_lock);
continue;
}
+ spin_unlock(&sbi->fs_lock);
+
+ expired = should_expire(dentry, mnt, timeout, flags);
+ if (!expired)
+ continue;
+
+ spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(expired);
ino->flags |= AUTOFS_INF_WANT_EXPIRE;
spin_unlock(&sbi->fs_lock);
synchronize_rcu();
- spin_lock(&sbi->fs_lock);
- if (should_expire(expired, mnt, timeout, how)) {
- if (expired != dentry)
- dput(dentry);
- goto found;
- }
+ /* Make sure a reference is not taken on found if
+ * things have changed.
+ */
+ flags &= ~AUTOFS_EXP_LEAVES;
+ found = should_expire(expired, mnt, timeout, how);
+ if (!found || found != expired)
+ /* Something has changed, continue */
+ goto next;
+
+ if (expired != dentry)
+ dput(dentry);
+
+ spin_lock(&sbi->fs_lock);
+ goto found;
+next:
+ spin_lock(&sbi->fs_lock);
ino->flags &= ~AUTOFS_INF_WANT_EXPIRE;
+ spin_unlock(&sbi->fs_lock);
if (expired != dentry)
dput(expired);
- spin_unlock(&sbi->fs_lock);
}
return NULL;
@@ -483,6 +500,7 @@ int autofs4_expire_wait(struct dentry *dentry, int rcu_walk)
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int status;
+ int state;
/* Block on any pending expire */
if (!(ino->flags & AUTOFS_INF_WANT_EXPIRE))
@@ -490,8 +508,19 @@ int autofs4_expire_wait(struct dentry *dentry, int rcu_walk)
if (rcu_walk)
return -ECHILD;
+retry:
spin_lock(&sbi->fs_lock);
- if (ino->flags & AUTOFS_INF_EXPIRING) {
+ state = ino->flags & (AUTOFS_INF_WANT_EXPIRE | AUTOFS_INF_EXPIRING);
+ if (state == AUTOFS_INF_WANT_EXPIRE) {
+ spin_unlock(&sbi->fs_lock);
+ /*
+ * Possibly being selected for expire, wait until
+ * it's selected or not.
+ */
+ schedule_timeout_uninterruptible(HZ/10);
+ goto retry;
+ }
+ if (state & AUTOFS_INF_EXPIRING) {
spin_unlock(&sbi->fs_lock);
pr_debug("waiting for expire %p name=%pd\n", dentry, dentry);
--
cgit v1.2.3-54-g00ecf