/* Too young to die */
if (!timeout || time_after(ino->last_used + timeout, now))
return 0;
-
- /* update last_used here :-
- - obviously makes sense if it is in use now
- - less obviously, prevents rapid-fire expire
- attempts if expire fails the first time */
- ino->last_used = now;
}
return 1;
}
struct path path = {.mnt = mnt, .dentry = dentry};
int status = 1;
- DPRINTK("dentry %p %.*s",
- dentry, (int)dentry->d_name.len, dentry->d_name.name);
+ DPRINTK("dentry %p %pd", dentry, dentry);
path_get(&path);
spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
/* Already gone or negative dentry (under construction) - try next */
- if (q->d_count == 0 || !simple_positive(q)) {
+ if (!d_count(q) || !simple_positive(q)) {
spin_unlock(&q->d_lock);
next = q->d_child.next;
goto cont;
unsigned long timeout,
int do_now)
{
- DPRINTK("top %p %.*s",
- top, (int) top->d_name.len, top->d_name.name);
+ DPRINTK("top %p %pd", top, top);
/* If it's busy update the expiry counters */
if (!may_umount_tree(mnt)) {
struct autofs_info *top_ino = autofs4_dentry_ino(top);
struct dentry *p;
- DPRINTK("top %p %.*s",
- top, (int)top->d_name.len, top->d_name.name);
+ DPRINTK("top %p %pd", top, top);
/* Negative dentry - give up */
if (!simple_positive(top))
p = NULL;
while ((p = get_next_positive_dentry(p, top))) {
- DPRINTK("dentry %p %.*s",
- p, (int) p->d_name.len, p->d_name.name);
+ DPRINTK("dentry %p %pd", p, p);
/*
* Is someone visiting anywhere in the subtree ?
struct autofs_info *ino = autofs4_dentry_ino(p);
unsigned int ino_count = atomic_read(&ino->count);
- /*
- * Clean stale dentries below that have not been
- * invalidated after a mount fail during lookup
- */
- d_invalidate(p);
-
/* allow for dget above and top is already dgot */
if (p == top)
ino_count += 2;
else
ino_count++;
- if (p->d_count > ino_count) {
+ if (d_count(p) > ino_count) {
top_ino->last_used = jiffies;
dput(p);
return 1;
{
struct dentry *p;
- DPRINTK("parent %p %.*s",
- parent, (int)parent->d_name.len, parent->d_name.name);
+ DPRINTK("parent %p %pd", parent, parent);
p = NULL;
while ((p = get_next_positive_dentry(p, parent))) {
- DPRINTK("dentry %p %.*s",
- p, (int) p->d_name.len, p->d_name.name);
+ DPRINTK("dentry %p %pd", p, p);
if (d_mountpoint(p)) {
/* Can we umount this guy */
if (ino->flags & AUTOFS_INF_PENDING)
goto out;
if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
- struct autofs_info *ino = autofs4_dentry_ino(root);
- ino->flags |= AUTOFS_INF_EXPIRING;
- init_completion(&ino->expire_complete);
+ ino->flags |= AUTOFS_INF_WANT_EXPIRE;
spin_unlock(&sbi->fs_lock);
- return root;
+ synchronize_rcu();
+ spin_lock(&sbi->fs_lock);
+ if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
+ ino->flags |= AUTOFS_INF_EXPIRING;
+ init_completion(&ino->expire_complete);
+ spin_unlock(&sbi->fs_lock);
+ return root;
+ }
+ ino->flags &= ~AUTOFS_INF_WANT_EXPIRE;
}
out:
spin_unlock(&sbi->fs_lock);
return NULL;
}
+/* Check if 'dentry' should expire, or return a nearby
+ * dentry that is suitable.
+ * If returned dentry is different from arg dentry,
+ * then a dget() reference was taken, else not.
+ */
+static struct dentry *should_expire(struct dentry *dentry,
+ struct vfsmount *mnt,
+ unsigned long timeout,
+ int how)
+{
+ int do_now = how & AUTOFS_EXP_IMMEDIATE;
+ int exp_leaves = how & AUTOFS_EXP_LEAVES;
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ unsigned int ino_count;
+
+ /* No point expiring a pending mount */
+ if (ino->flags & AUTOFS_INF_PENDING)
+ return NULL;
+
+ /*
+ * Case 1: (i) indirect mount or top level pseudo direct mount
+ * (autofs-4.1).
+ * (ii) indirect mount with offset mount, check the "/"
+ * offset (autofs-5.0+).
+ */
+ if (d_mountpoint(dentry)) {
+ DPRINTK("checking mountpoint %p %pd", dentry, dentry);
+
+ /* Can we umount this guy */
+ if (autofs4_mount_busy(mnt, dentry))
+ return NULL;
+
+ /* Can we expire this guy */
+ if (autofs4_can_expire(dentry, timeout, do_now))
+ return dentry;
+ return NULL;
+ }
+
+ if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
+ DPRINTK("checking symlink %p %pd", dentry, dentry);
+ /*
+ * A symlink can't be "busy" in the usual sense so
+ * just check last used for expire timeout.
+ */
+ if (autofs4_can_expire(dentry, timeout, do_now))
+ return dentry;
+ return NULL;
+ }
+
+ if (simple_empty(dentry))
+ return NULL;
+
+ /* Case 2: tree mount, expire iff entire tree is not busy */
+ if (!exp_leaves) {
+ /* Path walk currently on this dentry? */
+ ino_count = atomic_read(&ino->count) + 1;
+ if (d_count(dentry) > ino_count)
+ return NULL;
+
+ if (!autofs4_tree_busy(mnt, dentry, timeout, do_now))
+ return dentry;
+ /*
+ * Case 3: pseudo direct mount, expire individual leaves
+ * (autofs-4.1).
+ */
+ } else {
+ /* Path walk currently on this dentry? */
+ struct dentry *expired;
+ ino_count = atomic_read(&ino->count) + 1;
+ if (d_count(dentry) > ino_count)
+ return NULL;
+
+ expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
+ if (expired) {
+ if (expired == dentry)
+ dput(dentry);
+ return expired;
+ }
+ }
+ return NULL;
+}
+
/*
* Find an eligible tree to time-out
* A tree is eligible if :-
unsigned long timeout;
struct dentry *root = sb->s_root;
struct dentry *dentry;
- struct dentry *expired = NULL;
- int do_now = how & AUTOFS_EXP_IMMEDIATE;
- int exp_leaves = how & AUTOFS_EXP_LEAVES;
+ struct dentry *expired;
+ struct dentry *found;
struct autofs_info *ino;
- unsigned int ino_count;
if (!root)
return NULL;
dentry = NULL;
while ((dentry = get_next_positive_subdir(dentry, root))) {
+ int flags = how;
+
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
- /* No point expiring a pending mount */
- if (ino->flags & AUTOFS_INF_PENDING)
- goto next;
-
- /*
- * Case 1: (i) indirect mount or top level pseudo direct mount
- * (autofs-4.1).
- * (ii) indirect mount with offset mount, check the "/"
- * offset (autofs-5.0+).
- */
- if (d_mountpoint(dentry)) {
- DPRINTK("checking mountpoint %p %.*s",
- dentry, (int)dentry->d_name.len, dentry->d_name.name);
-
- /* Can we umount this guy */
- if (autofs4_mount_busy(mnt, dentry))
- goto next;
-
- /* Can we expire this guy */
- if (autofs4_can_expire(dentry, timeout, do_now)) {
- expired = dentry;
- goto found;
- }
- goto next;
+ if (ino->flags & AUTOFS_INF_WANT_EXPIRE) {
+ spin_unlock(&sbi->fs_lock);
+ continue;
}
+ spin_unlock(&sbi->fs_lock);
- if (simple_empty(dentry))
- goto next;
+ expired = should_expire(dentry, mnt, timeout, flags);
+ if (!expired)
+ continue;
- /* Case 2: tree mount, expire iff entire tree is not busy */
- if (!exp_leaves) {
- /* Path walk currently on this dentry? */
- ino_count = atomic_read(&ino->count) + 1;
- if (dentry->d_count > ino_count)
- goto next;
+ spin_lock(&sbi->fs_lock);
+ ino = autofs4_dentry_ino(expired);
+ ino->flags |= AUTOFS_INF_WANT_EXPIRE;
+ spin_unlock(&sbi->fs_lock);
+ synchronize_rcu();
- if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) {
- expired = dentry;
- goto found;
- }
- /*
- * Case 3: pseudo direct mount, expire individual leaves
- * (autofs-4.1).
+ /* Make sure a reference is not taken on found if
+ * things have changed.
*/
- } else {
- /* Path walk currently on this dentry? */
- ino_count = atomic_read(&ino->count) + 1;
- if (dentry->d_count > ino_count)
- goto next;
+ flags &= ~AUTOFS_EXP_LEAVES;
+ found = should_expire(expired, mnt, timeout, how);
+ if (!found || found != expired)
+ /* Something has changed, continue */
+ goto next;
- expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
- if (expired) {
- dput(dentry);
- goto found;
- }
- }
+ 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);
}
return NULL;
found:
- DPRINTK("returning %p %.*s",
- expired, (int)expired->d_name.len, expired->d_name.name);
- ino = autofs4_dentry_ino(expired);
+ DPRINTK("returning %p %pd", expired, expired);
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
- spin_lock(&sbi->lookup_lock);
- spin_lock(&expired->d_parent->d_lock);
- spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED);
- list_move(&expired->d_parent->d_subdirs, &expired->d_child);
- spin_unlock(&expired->d_lock);
- spin_unlock(&expired->d_parent->d_lock);
- spin_unlock(&sbi->lookup_lock);
return expired;
}
-int autofs4_expire_wait(struct dentry *dentry)
+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))
+ return 0;
+ 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);
- DPRINTK("waiting for expire %p name=%.*s",
- dentry, dentry->d_name.len, dentry->d_name.name);
+ DPRINTK("waiting for expire %p name=%pd", dentry, dentry);
status = autofs4_wait(sbi, dentry, NFY_NONE);
wait_for_completion(&ino->expire_complete);
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
- ino->flags &= ~AUTOFS_INF_EXPIRING;
+ /* avoid rapid-fire expire attempts if expiry fails */
+ ino->last_used = now;
+ ino->flags &= ~(AUTOFS_INF_EXPIRING|AUTOFS_INF_WANT_EXPIRE);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
ret = autofs4_wait(sbi, dentry, NFY_EXPIRE);
spin_lock(&sbi->fs_lock);
- ino->flags &= ~AUTOFS_INF_EXPIRING;
+ /* avoid rapid-fire expire attempts if expiry fails */
+ ino->last_used = now;
+ ino->flags &= ~(AUTOFS_INF_EXPIRING|AUTOFS_INF_WANT_EXPIRE);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
dput(dentry);
projects / firefly-linux-kernel-4.4.55.git / blobdiff