[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/autofs4/expire.c b/ap/os/linux/linux-3.4.x/fs/autofs4/expire.c
new file mode 100644
index 0000000..43df7e6
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/autofs4/expire.c
@@ -0,0 +1,581 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/expire.c
+ *
+ * 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"
+
+static unsigned long now;
+
+/* Check if a dentry can be expired */
+static inline int autofs4_can_expire(struct dentry *dentry,
+ unsigned long timeout, int do_now)
+{
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+ /* dentry in the process of being deleted */
+ if (ino == NULL)
+ return 0;
+
+ if (!do_now) {
+ /* 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;
+}
+
+/* Check a mount point for busyness */
+static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
+{
+ struct dentry *top = dentry;
+ struct path path = {.mnt = mnt, .dentry = dentry};
+ int status = 1;
+
+ DPRINTK("dentry %p %.*s",
+ dentry, (int)dentry->d_name.len, dentry->d_name.name);
+
+ path_get(&path);
+
+ if (!follow_down_one(&path))
+ goto done;
+
+ if (is_autofs4_dentry(path.dentry)) {
+ struct autofs_sb_info *sbi = autofs4_sbi(path.dentry->d_sb);
+
+ /* This is an autofs submount, we can't expire it */
+ if (autofs_type_indirect(sbi->type))
+ goto done;
+ }
+
+ /* Update the expiry counter if fs is busy */
+ if (!may_umount_tree(path.mnt)) {
+ struct autofs_info *ino = autofs4_dentry_ino(top);
+ ino->last_used = jiffies;
+ goto done;
+ }
+
+ status = 0;
+done:
+ DPRINTK("returning = %d", status);
+ path_put(&path);
+ return status;
+}
+
+/*
+ * Calculate and dget next entry in the subdirs list under root.
+ */
+static struct dentry *get_next_positive_subdir(struct dentry *prev,
+ struct dentry *root)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
+ struct list_head *next;
+ struct dentry *p, *q;
+
+ spin_lock(&sbi->lookup_lock);
+
+ if (prev == NULL) {
+ spin_lock(&root->d_lock);
+ prev = dget_dlock(root);
+ next = prev->d_subdirs.next;
+ p = prev;
+ goto start;
+ }
+
+ p = prev;
+ spin_lock(&p->d_lock);
+again:
+ next = p->d_child.next;
+start:
+ if (next == &root->d_subdirs) {
+ spin_unlock(&p->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);
+ /* Negative dentry - try next */
+ if (!simple_positive(q)) {
+ spin_unlock(&p->d_lock);
+ lock_set_subclass(&q->d_lock.dep_map, 0, _RET_IP_);
+ p = q;
+ goto again;
+ }
+ dget_dlock(q);
+ spin_unlock(&q->d_lock);
+ spin_unlock(&p->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+
+ dput(prev);
+
+ return q;
+}
+
+/*
+ * Calculate and dget next entry in top down tree traversal.
+ */
+static struct dentry *get_next_positive_dentry(struct dentry *prev,
+ struct dentry *root)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
+ struct list_head *next;
+ struct dentry *p, *ret;
+
+ 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_chill();
+ 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);
+
+ spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED);
+ /* Negative dentry - try next */
+ if (!simple_positive(ret)) {
+ spin_unlock(&p->d_lock);
+ lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_);
+ p = ret;
+ goto again;
+ }
+ dget_dlock(ret);
+ spin_unlock(&ret->d_lock);
+ spin_unlock(&p->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+
+ dput(prev);
+
+ return ret;
+}
+
+/*
+ * Check a direct mount point for busyness.
+ * Direct mounts have similar expiry semantics to tree mounts.
+ * The tree is not busy iff no mountpoints are busy and there are no
+ * autofs submounts.
+ */
+static int autofs4_direct_busy(struct vfsmount *mnt,
+ struct dentry *top,
+ unsigned long timeout,
+ int do_now)
+{
+ DPRINTK("top %p %.*s",
+ top, (int) top->d_name.len, top->d_name.name);
+
+ /* If it's busy update the expiry counters */
+ if (!may_umount_tree(mnt)) {
+ struct autofs_info *ino = autofs4_dentry_ino(top);
+ if (ino)
+ ino->last_used = jiffies;
+ return 1;
+ }
+
+ /* Timeout of a direct mount is determined by its top dentry */
+ if (!autofs4_can_expire(top, timeout, do_now))
+ return 1;
+
+ return 0;
+}
+
+/* Check a directory tree of mount points for busyness
+ * The tree is not busy iff no mountpoints are busy
+ */
+static int autofs4_tree_busy(struct vfsmount *mnt,
+ struct dentry *top,
+ unsigned long timeout,
+ int do_now)
+{
+ 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);
+
+ /* Negative dentry - give up */
+ if (!simple_positive(top))
+ return 1;
+
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, top))) {
+ DPRINTK("dentry %p %.*s",
+ p, (int) p->d_name.len, p->d_name.name);
+
+ /*
+ * Is someone visiting anywhere in the subtree ?
+ * If there's no mount we need to check the usage
+ * count for the autofs dentry.
+ * If the fs is busy update the expiry counter.
+ */
+ if (d_mountpoint(p)) {
+ if (autofs4_mount_busy(mnt, p)) {
+ top_ino->last_used = jiffies;
+ dput(p);
+ return 1;
+ }
+ } else {
+ 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) {
+ top_ino->last_used = jiffies;
+ dput(p);
+ return 1;
+ }
+ }
+ }
+
+ /* Timeout of a tree mount is ultimately determined by its top dentry */
+ if (!autofs4_can_expire(top, timeout, do_now))
+ return 1;
+
+ return 0;
+}
+
+static struct dentry *autofs4_check_leaves(struct vfsmount *mnt,
+ struct dentry *parent,
+ unsigned long timeout,
+ int do_now)
+{
+ struct dentry *p;
+
+ DPRINTK("parent %p %.*s",
+ parent, (int)parent->d_name.len, parent->d_name.name);
+
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, parent))) {
+ DPRINTK("dentry %p %.*s",
+ p, (int) p->d_name.len, p->d_name.name);
+
+ if (d_mountpoint(p)) {
+ /* Can we umount this guy */
+ if (autofs4_mount_busy(mnt, p))
+ continue;
+
+ /* Can we expire this guy */
+ if (autofs4_can_expire(p, timeout, do_now))
+ return p;
+ }
+ }
+ return NULL;
+}
+
+/* Check if we can expire a direct mount (possibly a tree) */
+struct dentry *autofs4_expire_direct(struct super_block *sb,
+ struct vfsmount *mnt,
+ struct autofs_sb_info *sbi,
+ int how)
+{
+ unsigned long timeout;
+ struct dentry *root = dget(sb->s_root);
+ int do_now = how & AUTOFS_EXP_IMMEDIATE;
+ struct autofs_info *ino;
+
+ if (!root)
+ return NULL;
+
+ now = jiffies;
+ timeout = sbi->exp_timeout;
+
+ spin_lock(&sbi->fs_lock);
+ ino = autofs4_dentry_ino(root);
+ /* No point expiring a pending mount */
+ 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);
+ spin_unlock(&sbi->fs_lock);
+ return root;
+ }
+out:
+ spin_unlock(&sbi->fs_lock);
+ dput(root);
+
+ return NULL;
+}
+
+/*
+ * Find an eligible tree to time-out
+ * A tree is eligible if :-
+ * - it is unused by any user process
+ * - it has been unused for exp_timeout time
+ */
+struct dentry *autofs4_expire_indirect(struct super_block *sb,
+ struct vfsmount *mnt,
+ struct autofs_sb_info *sbi,
+ int how)
+{
+ 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 autofs_info *ino;
+ unsigned int ino_count;
+
+ if (!root)
+ return NULL;
+
+ now = jiffies;
+ timeout = sbi->exp_timeout;
+
+ dentry = NULL;
+ while ((dentry = get_next_positive_subdir(dentry, root))) {
+ 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);
+
+ /* Path walk currently on this dentry? */
+ ino_count = atomic_read(&ino->count) + 2;
+ if (dentry->d_count > ino_count)
+ goto next;
+
+ /* 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 (simple_empty(dentry))
+ goto next;
+
+ /* 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;
+
+ if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) {
+ expired = dentry;
+ goto found;
+ }
+ /*
+ * Case 3: pseudo direct mount, expire individual leaves
+ * (autofs-4.1).
+ */
+ } else {
+ /* Path walk currently on this dentry? */
+ ino_count = atomic_read(&ino->count) + 1;
+ if (dentry->d_count > ino_count)
+ goto next;
+
+ expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
+ if (expired) {
+ dput(dentry);
+ goto found;
+ }
+ }
+next:
+ spin_unlock(&sbi->fs_lock);
+ }
+ return NULL;
+
+found:
+ DPRINTK("returning %p %.*s",
+ expired, (int)expired->d_name.len, expired->d_name.name);
+ ino = autofs4_dentry_ino(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)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ int status;
+
+ /* Block on any pending expire */
+ spin_lock(&sbi->fs_lock);
+ if (ino->flags & AUTOFS_INF_EXPIRING) {
+ spin_unlock(&sbi->fs_lock);
+
+ DPRINTK("waiting for expire %p name=%.*s",
+ dentry, dentry->d_name.len, dentry->d_name.name);
+
+ status = autofs4_wait(sbi, dentry, NFY_NONE);
+ wait_for_completion(&ino->expire_complete);
+
+ DPRINTK("expire done status=%d", status);
+
+ if (d_unhashed(dentry))
+ return -EAGAIN;
+
+ return status;
+ }
+ spin_unlock(&sbi->fs_lock);
+
+ return 0;
+}
+
+/* Perform an expiry operation */
+int autofs4_expire_run(struct super_block *sb,
+ struct vfsmount *mnt,
+ struct autofs_sb_info *sbi,
+ struct autofs_packet_expire __user *pkt_p)
+{
+ struct autofs_packet_expire pkt;
+ struct autofs_info *ino;
+ struct dentry *dentry;
+ int ret = 0;
+
+ memset(&pkt,0,sizeof pkt);
+
+ pkt.hdr.proto_version = sbi->version;
+ pkt.hdr.type = autofs_ptype_expire;
+
+ if ((dentry = autofs4_expire_indirect(sb, mnt, sbi, 0)) == NULL)
+ return -EAGAIN;
+
+ 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;
+
+ spin_lock(&sbi->fs_lock);
+ ino = autofs4_dentry_ino(dentry);
+ ino->flags &= ~AUTOFS_INF_EXPIRING;
+ complete_all(&ino->expire_complete);
+ spin_unlock(&sbi->fs_lock);
+
+ return ret;
+}
+
+int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+ struct autofs_sb_info *sbi, int when)
+{
+ struct dentry *dentry;
+ int ret = -EAGAIN;
+
+ if (autofs_type_trigger(sbi->type))
+ dentry = autofs4_expire_direct(sb, mnt, sbi, when);
+ else
+ dentry = autofs4_expire_indirect(sb, mnt, sbi, when);
+
+ if (dentry) {
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+ /* This is synchronous because it makes the daemon a
+ little easier */
+ ret = autofs4_wait(sbi, dentry, NFY_EXPIRE);
+
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_EXPIRING;
+ spin_lock(&dentry->d_lock);
+ if (!ret) {
+ if ((IS_ROOT(dentry) ||
+ (autofs_type_indirect(sbi->type) &&
+ IS_ROOT(dentry->d_parent))) &&
+ !(dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
+ __managed_dentry_set_automount(dentry);
+ }
+ spin_unlock(&dentry->d_lock);
+ complete_all(&ino->expire_complete);
+ spin_unlock(&sbi->fs_lock);
+ dput(dentry);
+ }
+
+ return ret;
+}
+
+/* Call repeatedly until it returns -EAGAIN, meaning there's nothing
+ more to be done */
+int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+ struct autofs_sb_info *sbi, int __user *arg)
+{
+ int do_now = 0;
+
+ if (arg && get_user(do_now, arg))
+ return -EFAULT;
+
+ return autofs4_do_expire_multi(sb, mnt, sbi, do_now);
+}
+