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Diffstat (limited to 'fs/autofs/expire.c')
-rw-r--r--fs/autofs/expire.c130
1 files changed, 45 insertions, 85 deletions
diff --git a/fs/autofs/expire.c b/fs/autofs/expire.c
index d441244b79df..5c2d459e1e48 100644
--- a/fs/autofs/expire.c
+++ b/fs/autofs/expire.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
* Copyright 2001-2006 Ian Kent <raven@themaw.net>
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
*/
#include "autofs_i.h"
@@ -73,6 +70,24 @@ done:
return status;
}
+/* p->d_lock held */
+static struct dentry *positive_after(struct dentry *p, struct dentry *child)
+{
+ child = child ? d_next_sibling(child) : d_first_child(p);
+
+ hlist_for_each_entry_from(child, d_sib) {
+ spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
+ if (simple_positive(child)) {
+ dget_dlock(child);
+ spin_unlock(&child->d_lock);
+ return child;
+ }
+ spin_unlock(&child->d_lock);
+ }
+
+ return NULL;
+}
+
/*
* Calculate and dget next entry in the subdirs list under root.
*/
@@ -80,43 +95,14 @@ static struct dentry *get_next_positive_subdir(struct dentry *prev,
struct dentry *root)
{
struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
- struct list_head *next;
struct dentry *q;
spin_lock(&sbi->lookup_lock);
spin_lock(&root->d_lock);
-
- if (prev)
- next = prev->d_child.next;
- else {
- prev = dget_dlock(root);
- next = prev->d_subdirs.next;
- }
-
-cont:
- if (next == &root->d_subdirs) {
- spin_unlock(&root->d_lock);
- spin_unlock(&sbi->lookup_lock);
- dput(prev);
- return NULL;
- }
-
- q = list_entry(next, struct dentry, d_child);
-
- spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
- /* Already gone or negative dentry (under construction) - try next */
- if (!d_count(q) || !simple_positive(q)) {
- spin_unlock(&q->d_lock);
- next = q->d_child.next;
- goto cont;
- }
- dget_dlock(q);
- spin_unlock(&q->d_lock);
+ q = positive_after(root, prev);
spin_unlock(&root->d_lock);
spin_unlock(&sbi->lookup_lock);
-
dput(prev);
-
return q;
}
@@ -127,59 +113,28 @@ static struct dentry *get_next_positive_dentry(struct dentry *prev,
struct dentry *root)
{
struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
- struct list_head *next;
- struct dentry *p, *ret;
+ struct dentry *p = prev, *ret = NULL, *d = NULL;
if (prev == NULL)
return dget(root);
spin_lock(&sbi->lookup_lock);
-relock:
- p = prev;
spin_lock(&p->d_lock);
-again:
- next = p->d_subdirs.next;
- if (next == &p->d_subdirs) {
- while (1) {
- struct dentry *parent;
-
- if (p == root) {
- spin_unlock(&p->d_lock);
- spin_unlock(&sbi->lookup_lock);
- dput(prev);
- return NULL;
- }
-
- parent = p->d_parent;
- if (!spin_trylock(&parent->d_lock)) {
- spin_unlock(&p->d_lock);
- cpu_relax();
- goto relock;
- }
- spin_unlock(&p->d_lock);
- next = p->d_child.next;
- p = parent;
- if (next != &parent->d_subdirs)
- break;
- }
- }
- ret = list_entry(next, struct dentry, d_child);
+ while (1) {
+ struct dentry *parent;
- spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED);
- /* Negative dentry - try next */
- if (!simple_positive(ret)) {
+ ret = positive_after(p, d);
+ if (ret || p == root)
+ break;
+ parent = p->d_parent;
spin_unlock(&p->d_lock);
- lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_);
- p = ret;
- goto again;
+ spin_lock(&parent->d_lock);
+ d = p;
+ p = parent;
}
- dget_dlock(ret);
- spin_unlock(&ret->d_lock);
spin_unlock(&p->d_lock);
spin_unlock(&sbi->lookup_lock);
-
dput(prev);
-
return ret;
}
@@ -253,7 +208,7 @@ static int autofs_tree_busy(struct vfsmount *mnt,
}
} else {
struct autofs_info *ino = autofs_dentry_ino(p);
- unsigned int ino_count = atomic_read(&ino->count);
+ unsigned int ino_count = READ_ONCE(ino->count);
/* allow for dget above and top is already dgot */
if (p == top)
@@ -397,7 +352,7 @@ static struct dentry *should_expire(struct dentry *dentry,
return NULL;
}
- if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
+ if (d_is_symlink(dentry)) {
pr_debug("checking symlink %p %pd\n", dentry, dentry);
/* Forced expire, user space handles busy mounts */
@@ -413,7 +368,7 @@ static struct dentry *should_expire(struct dentry *dentry,
return NULL;
}
- if (simple_empty(dentry))
+ if (autofs_empty(ino))
return NULL;
/* Case 2: tree mount, expire iff entire tree is not busy */
@@ -421,7 +376,7 @@ static struct dentry *should_expire(struct dentry *dentry,
/* Not a forced expire? */
if (!(how & AUTOFS_EXP_FORCED)) {
/* ref-walk currently on this dentry? */
- ino_count = atomic_read(&ino->count) + 1;
+ ino_count = READ_ONCE(ino->count) + 1;
if (d_count(dentry) > ino_count)
return NULL;
}
@@ -438,7 +393,7 @@ static struct dentry *should_expire(struct dentry *dentry,
/* Not a forced expire? */
if (!(how & AUTOFS_EXP_FORCED)) {
/* ref-walk currently on this dentry? */
- ino_count = atomic_read(&ino->count) + 1;
+ ino_count = READ_ONCE(ino->count) + 1;
if (d_count(dentry) > ino_count)
return NULL;
}
@@ -474,8 +429,6 @@ static struct dentry *autofs_expire_indirect(struct super_block *sb,
if (!root)
return NULL;
- timeout = sbi->exp_timeout;
-
dentry = NULL;
while ((dentry = get_next_positive_subdir(dentry, root))) {
spin_lock(&sbi->fs_lock);
@@ -486,6 +439,11 @@ static struct dentry *autofs_expire_indirect(struct super_block *sb,
}
spin_unlock(&sbi->fs_lock);
+ if (ino->flags & AUTOFS_INF_EXPIRE_SET)
+ timeout = ino->exp_timeout;
+ else
+ timeout = sbi->exp_timeout;
+
expired = should_expire(dentry, mnt, timeout, how);
if (!expired)
continue;
@@ -501,9 +459,10 @@ static struct dentry *autofs_expire_indirect(struct super_block *sb,
*/
how &= ~AUTOFS_EXP_LEAVES;
found = should_expire(expired, mnt, timeout, how);
- if (!found || found != expired)
- /* Something has changed, continue */
+ if (found != expired) { // something has changed, continue
+ dput(found);
goto next;
+ }
if (expired != dentry)
dput(dentry);
@@ -596,7 +555,6 @@ int autofs_expire_run(struct super_block *sb,
pkt.len = dentry->d_name.len;
memcpy(pkt.name, dentry->d_name.name, pkt.len);
pkt.name[pkt.len] = '\0';
- dput(dentry);
if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
ret = -EFAULT;
@@ -609,6 +567,8 @@ int autofs_expire_run(struct super_block *sb,
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
+ dput(dentry);
+
return ret;
}
generated by cgit (git 2.34.1) at 2025-12-24 21:58:39 +0000