Revert "autofs4: always use lookup for lookup"
Al Viro [Wed, 3 Mar 2010 17:58:31 +0000 (12:58 -0500)]
This reverts commit 213614d583748d00967a91cacd656f417efb36ce.

Alas, ->d_revalidate() can't rely on ->lookup() finishing what
it's started; if d_alloc() in do_lookup() fails, we are not going
to call ->lookup() at all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/autofs4/autofs_i.h
fs/autofs4/expire.c
fs/autofs4/inode.c
fs/autofs4/root.c

index 0118d67..3d283ab 100644 (file)
@@ -60,11 +60,6 @@ do {                                                 \
                current->pid, __func__, ##args);        \
 } while (0)
 
-struct rehash_entry {
-       struct task_struct *task;
-       struct list_head list;
-};
-
 /* Unified info structure.  This is pointed to by both the dentry and
    inode structures.  Each file in the filesystem has an instance of this
    structure.  It holds a reference to the dentry, so dentries are never
@@ -81,7 +76,6 @@ struct autofs_info {
 
        struct list_head active;
        int active_count;
-       struct list_head rehash_list;
 
        struct list_head expiring;
 
@@ -104,7 +98,6 @@ struct autofs_info {
 #define AUTOFS_INF_EXPIRING    (1<<0) /* dentry is in the process of expiring */
 #define AUTOFS_INF_MOUNTPOINT  (1<<1) /* mountpoint status for direct expire */
 #define AUTOFS_INF_PENDING     (1<<2) /* dentry pending mount */
-#define AUTOFS_INF_REHASH      (1<<3) /* dentry in transit to ->lookup() */
 
 struct autofs_wait_queue {
        wait_queue_head_t queue;
index 74bc9aa..a796c94 100644 (file)
@@ -279,7 +279,6 @@ struct dentry *autofs4_expire_direct(struct super_block *sb,
                        root->d_mounted--;
                }
                ino->flags |= AUTOFS_INF_EXPIRING;
-               autofs4_add_expiring(root);
                init_completion(&ino->expire_complete);
                spin_unlock(&sbi->fs_lock);
                return root;
@@ -407,7 +406,6 @@ found:
                expired, (int)expired->d_name.len, expired->d_name.name);
        ino = autofs4_dentry_ino(expired);
        ino->flags |= AUTOFS_INF_EXPIRING;
-       autofs4_add_expiring(expired);
        init_completion(&ino->expire_complete);
        spin_unlock(&sbi->fs_lock);
        spin_lock(&dcache_lock);
@@ -435,7 +433,7 @@ int autofs4_expire_wait(struct dentry *dentry)
 
                DPRINTK("expire done status=%d", status);
 
-               if (d_unhashed(dentry) && IS_DEADDIR(dentry->d_inode))
+               if (d_unhashed(dentry))
                        return -EAGAIN;
 
                return status;
@@ -475,7 +473,6 @@ int autofs4_expire_run(struct super_block *sb,
        spin_lock(&sbi->fs_lock);
        ino = autofs4_dentry_ino(dentry);
        ino->flags &= ~AUTOFS_INF_EXPIRING;
-       autofs4_del_expiring(dentry);
        complete_all(&ino->expire_complete);
        spin_unlock(&sbi->fs_lock);
 
@@ -506,7 +503,6 @@ int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
                        ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
                }
                ino->flags &= ~AUTOFS_INF_EXPIRING;
-               autofs4_del_expiring(dentry);
                complete_all(&ino->expire_complete);
                spin_unlock(&sbi->fs_lock);
                dput(dentry);
index d0a3de2..4670a78 100644 (file)
@@ -49,7 +49,6 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
                ino->dentry = NULL;
                ino->size = 0;
                INIT_LIST_HEAD(&ino->active);
-               INIT_LIST_HEAD(&ino->rehash_list);
                ino->active_count = 0;
                INIT_LIST_HEAD(&ino->expiring);
                atomic_set(&ino->count, 0);
index 30cc9dd..a015b49 100644 (file)
@@ -104,99 +104,6 @@ static void autofs4_del_active(struct dentry *dentry)
        return;
 }
 
-static void autofs4_add_rehash_entry(struct autofs_info *ino,
-                                    struct rehash_entry *entry)
-{
-       entry->task = current;
-       INIT_LIST_HEAD(&entry->list);
-       list_add(&entry->list, &ino->rehash_list);
-       return;
-}
-
-static void autofs4_remove_rehash_entry(struct autofs_info *ino)
-{
-       struct list_head *head = &ino->rehash_list;
-       struct rehash_entry *entry;
-       list_for_each_entry(entry, head, list) {
-               if (entry->task == current) {
-                       list_del(&entry->list);
-                       kfree(entry);
-                       break;
-               }
-       }
-       return;
-}
-
-static void autofs4_remove_rehash_entrys(struct autofs_info *ino)
-{
-       struct autofs_sb_info *sbi = ino->sbi;
-       struct rehash_entry *entry, *next;
-       struct list_head *head;
-
-       spin_lock(&sbi->fs_lock);
-       spin_lock(&sbi->lookup_lock);
-       if (!(ino->flags & AUTOFS_INF_REHASH)) {
-               spin_unlock(&sbi->lookup_lock);
-               spin_unlock(&sbi->fs_lock);
-               return;
-       }
-       ino->flags &= ~AUTOFS_INF_REHASH;
-       head = &ino->rehash_list;
-       list_for_each_entry_safe(entry, next, head, list) {
-               list_del(&entry->list);
-               kfree(entry);
-       }
-       spin_unlock(&sbi->lookup_lock);
-       spin_unlock(&sbi->fs_lock);
-       dput(ino->dentry);
-
-       return;
-}
-
-static void autofs4_revalidate_drop(struct dentry *dentry,
-                                   struct rehash_entry *entry)
-{
-       struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-       struct autofs_info *ino = autofs4_dentry_ino(dentry);
-       /*
-        * Add to the active list so we can pick this up in
-        * ->lookup(). Also add an entry to a rehash list so
-        * we know when there are no dentrys in flight so we
-        * know when we can rehash the dentry.
-        */
-       spin_lock(&sbi->lookup_lock);
-       if (list_empty(&ino->active))
-               list_add(&ino->active, &sbi->active_list);
-       autofs4_add_rehash_entry(ino, entry);
-       spin_unlock(&sbi->lookup_lock);
-       if (!(ino->flags & AUTOFS_INF_REHASH)) {
-               ino->flags |= AUTOFS_INF_REHASH;
-               dget(dentry);
-               spin_lock(&dentry->d_lock);
-               __d_drop(dentry);
-               spin_unlock(&dentry->d_lock);
-       }
-       return;
-}
-
-static void autofs4_revalidate_rehash(struct dentry *dentry)
-{
-       struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-       struct autofs_info *ino = autofs4_dentry_ino(dentry);
-       if (ino->flags & AUTOFS_INF_REHASH) {
-               spin_lock(&sbi->lookup_lock);
-               autofs4_remove_rehash_entry(ino);
-               if (list_empty(&ino->rehash_list)) {
-                       spin_unlock(&sbi->lookup_lock);
-                       ino->flags &= ~AUTOFS_INF_REHASH;
-                       d_rehash(dentry);
-                       dput(ino->dentry);
-               } else
-                       spin_unlock(&sbi->lookup_lock);
-       }
-       return;
-}
-
 static unsigned int autofs4_need_mount(unsigned int flags)
 {
        unsigned int res = 0;
@@ -236,7 +143,7 @@ out:
        return dcache_dir_open(inode, file);
 }
 
-static int try_to_fill_dentry(struct dentry *dentry)
+static int try_to_fill_dentry(struct dentry *dentry, int flags)
 {
        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
        struct autofs_info *ino = autofs4_dentry_ino(dentry);
@@ -249,17 +156,55 @@ static int try_to_fill_dentry(struct dentry *dentry)
         * Wait for a pending mount, triggering one if there
         * isn't one already
         */
-       DPRINTK("waiting for mount name=%.*s",
-                dentry->d_name.len, dentry->d_name.name);
+       if (dentry->d_inode == NULL) {
+               DPRINTK("waiting for mount name=%.*s",
+                        dentry->d_name.len, dentry->d_name.name);
 
-       status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+               status = autofs4_wait(sbi, dentry, NFY_MOUNT);
 
-       DPRINTK("mount done status=%d", status);
+               DPRINTK("mount done status=%d", status);
 
-       /* Update expiry counter */
-       ino->last_used = jiffies;
+               /* Turn this into a real negative dentry? */
+               if (status == -ENOENT) {
+                       spin_lock(&sbi->fs_lock);
+                       ino->flags &= ~AUTOFS_INF_PENDING;
+                       spin_unlock(&sbi->fs_lock);
+                       return status;
+               } else if (status) {
+                       /* Return a negative dentry, but leave it "pending" */
+                       return status;
+               }
+       /* Trigger mount for path component or follow link */
+       } else if (ino->flags & AUTOFS_INF_PENDING ||
+                       autofs4_need_mount(flags) ||
+                       current->link_count) {
+               DPRINTK("waiting for mount name=%.*s",
+                       dentry->d_name.len, dentry->d_name.name);
 
-       return status;
+               spin_lock(&sbi->fs_lock);
+               ino->flags |= AUTOFS_INF_PENDING;
+               spin_unlock(&sbi->fs_lock);
+               status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+
+               DPRINTK("mount done status=%d", status);
+
+               if (status) {
+                       spin_lock(&sbi->fs_lock);
+                       ino->flags &= ~AUTOFS_INF_PENDING;
+                       spin_unlock(&sbi->fs_lock);
+                       return status;
+               }
+       }
+
+       /* Initialize expiry counter after successful mount */
+       if (ino)
+               ino->last_used = jiffies;
+
+       spin_lock(&sbi->fs_lock);
+       ino->flags &= ~AUTOFS_INF_PENDING;
+       spin_unlock(&sbi->fs_lock);
+
+       return 0;
 }
 
 /* For autofs direct mounts the follow link triggers the mount */
@@ -313,16 +258,10 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
         */
        if (ino->flags & AUTOFS_INF_PENDING ||
            (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
-               ino->flags |= AUTOFS_INF_PENDING;
                spin_unlock(&dcache_lock);
                spin_unlock(&sbi->fs_lock);
 
-               status = try_to_fill_dentry(dentry);
-
-               spin_lock(&sbi->fs_lock);
-               ino->flags &= ~AUTOFS_INF_PENDING;
-               spin_unlock(&sbi->fs_lock);
-
+               status = try_to_fill_dentry(dentry, 0);
                if (status)
                        goto out_error;
 
@@ -361,47 +300,18 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
        struct inode *dir = dentry->d_parent->d_inode;
        struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
-       struct autofs_info *ino = autofs4_dentry_ino(dentry);
-       struct rehash_entry *entry;
+       int oz_mode = autofs4_oz_mode(sbi);
        int flags = nd ? nd->flags : 0;
-       unsigned int mutex_aquired;
+       int status = 1;
 
-       DPRINTK("name = %.*s oz_mode = %d",
-               dentry->d_name.len, dentry->d_name.name, oz_mode);
-
-       /* Daemon never causes a mount to trigger */
-       if (autofs4_oz_mode(sbi))
-               return 1;
-
-       entry = kmalloc(sizeof(struct rehash_entry), GFP_KERNEL);
-       if (!entry)
-               return -ENOMEM;
-
-       mutex_aquired = mutex_trylock(&dir->i_mutex);
-
-       spin_lock(&sbi->fs_lock);
-       spin_lock(&dcache_lock);
        /* Pending dentry */
+       spin_lock(&sbi->fs_lock);
        if (autofs4_ispending(dentry)) {
-               int status;
-
-               /*
-                * We can only unhash and send this to ->lookup() if
-                * the directory mutex is held over d_revalidate() and
-                * ->lookup(). This prevents the VFS from incorrectly
-                * seeing the dentry as non-existent.
-                */
-               ino->flags |= AUTOFS_INF_PENDING;
-               if (!mutex_aquired) {
-                       autofs4_revalidate_drop(dentry, entry);
-                       spin_unlock(&dcache_lock);
-                       spin_unlock(&sbi->fs_lock);
-                       return 0;
-               }
-               spin_unlock(&dcache_lock);
+               /* The daemon never causes a mount to trigger */
                spin_unlock(&sbi->fs_lock);
-               mutex_unlock(&dir->i_mutex);
-               kfree(entry);
+
+               if (oz_mode)
+                       return 1;
 
                /*
                 * If the directory has gone away due to an expire
@@ -415,82 +325,45 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
                 * A zero status is success otherwise we have a
                 * negative error code.
                 */
-               status = try_to_fill_dentry(dentry);
-
-               spin_lock(&sbi->fs_lock);
-               ino->flags &= ~AUTOFS_INF_PENDING;
-               spin_unlock(&sbi->fs_lock);
-
+               status = try_to_fill_dentry(dentry, flags);
                if (status == 0)
                        return 1;
 
                return status;
        }
+       spin_unlock(&sbi->fs_lock);
+
+       /* Negative dentry.. invalidate if "old" */
+       if (dentry->d_inode == NULL)
+               return 0;
 
        /* Check for a non-mountpoint directory with no contents */
+       spin_lock(&dcache_lock);
        if (S_ISDIR(dentry->d_inode->i_mode) &&
            !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
                DPRINTK("dentry=%p %.*s, emptydir",
                         dentry, dentry->d_name.len, dentry->d_name.name);
+               spin_unlock(&dcache_lock);
 
-               if (autofs4_need_mount(flags) || current->link_count) {
-                       int status;
-
-                       /*
-                        * We can only unhash and send this to ->lookup() if
-                        * the directory mutex is held over d_revalidate() and
-                        * ->lookup(). This prevents the VFS from incorrectly
-                        * seeing the dentry as non-existent.
-                        */
-                       ino->flags |= AUTOFS_INF_PENDING;
-                       if (!mutex_aquired) {
-                               autofs4_revalidate_drop(dentry, entry);
-                               spin_unlock(&dcache_lock);
-                               spin_unlock(&sbi->fs_lock);
-                               return 0;
-                       }
-                       spin_unlock(&dcache_lock);
-                       spin_unlock(&sbi->fs_lock);
-                       mutex_unlock(&dir->i_mutex);
-                       kfree(entry);
-
-                       /*
-                        * A zero status is success otherwise we have a
-                        * negative error code.
-                        */
-                       status = try_to_fill_dentry(dentry);
-
-                       spin_lock(&sbi->fs_lock);
-                       ino->flags &= ~AUTOFS_INF_PENDING;
-                       spin_unlock(&sbi->fs_lock);
+               /* The daemon never causes a mount to trigger */
+               if (oz_mode)
+                       return 1;
 
-                       if (status == 0)
-                               return 1;
+               /*
+                * A zero status is success otherwise we have a
+                * negative error code.
+                */
+               status = try_to_fill_dentry(dentry, flags);
+               if (status == 0)
+                       return 1;
 
-                       return status;
-               }
+               return status;
        }
        spin_unlock(&dcache_lock);
-       spin_unlock(&sbi->fs_lock);
-
-       if (mutex_aquired)
-               mutex_unlock(&dir->i_mutex);
-
-       kfree(entry);
 
        return 1;
 }
 
-static void autofs4_free_rehash_entrys(struct autofs_info *inf)
-{
-       struct list_head *head = &inf->rehash_list;
-       struct rehash_entry *entry, *next;
-       list_for_each_entry_safe(entry, next, head, list) {
-               list_del(&entry->list);
-               kfree(entry);
-       }
-}
-
 void autofs4_dentry_release(struct dentry *de)
 {
        struct autofs_info *inf;
@@ -509,8 +382,6 @@ void autofs4_dentry_release(struct dentry *de)
                                list_del(&inf->active);
                        if (!list_empty(&inf->expiring))
                                list_del(&inf->expiring);
-                       if (!list_empty(&inf->rehash_list))
-                               autofs4_free_rehash_entrys(inf);
                        spin_unlock(&sbi->lookup_lock);
                }
 
@@ -543,7 +414,6 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
        const unsigned char *str = name->name;
        struct list_head *p, *head;
 
-restart:
        spin_lock(&dcache_lock);
        spin_lock(&sbi->lookup_lock);
        head = &sbi->active_list;
@@ -561,19 +431,6 @@ restart:
                if (atomic_read(&active->d_count) == 0)
                        goto next;
 
-               if (active->d_inode && IS_DEADDIR(active->d_inode)) {
-                       if (!list_empty(&ino->rehash_list)) {
-                               dget(active);
-                               spin_unlock(&active->d_lock);
-                               spin_unlock(&sbi->lookup_lock);
-                               spin_unlock(&dcache_lock);
-                               autofs4_remove_rehash_entrys(ino);
-                               dput(active);
-                               goto restart;
-                       }
-                       goto next;
-               }
-
                qstr = &active->d_name;
 
                if (active->d_name.hash != hash)
@@ -586,11 +443,13 @@ restart:
                if (memcmp(qstr->name, str, len))
                        goto next;
 
-               dget(active);
-               spin_unlock(&active->d_lock);
-               spin_unlock(&sbi->lookup_lock);
-               spin_unlock(&dcache_lock);
-               return active;
+               if (d_unhashed(active)) {
+                       dget(active);
+                       spin_unlock(&active->d_lock);
+                       spin_unlock(&sbi->lookup_lock);
+                       spin_unlock(&dcache_lock);
+                       return active;
+               }
 next:
                spin_unlock(&active->d_lock);
        }
@@ -639,11 +498,13 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
                if (memcmp(qstr->name, str, len))
                        goto next;
 
-               dget(expiring);
-               spin_unlock(&expiring->d_lock);
-               spin_unlock(&sbi->lookup_lock);
-               spin_unlock(&dcache_lock);
-               return expiring;
+               if (d_unhashed(expiring)) {
+                       dget(expiring);
+                       spin_unlock(&expiring->d_lock);
+                       spin_unlock(&sbi->lookup_lock);
+                       spin_unlock(&dcache_lock);
+                       return expiring;
+               }
 next:
                spin_unlock(&expiring->d_lock);
        }
@@ -653,48 +514,6 @@ next:
        return NULL;
 }
 
-static struct autofs_info *init_new_dentry(struct autofs_sb_info *sbi,
-                                          struct dentry *dentry, int oz_mode)
-{
-       struct autofs_info *ino;
-
-       /*
-        * Mark the dentry incomplete but don't hash it. We do this
-        * to serialize our inode creation operations (symlink and
-        * mkdir) which prevents deadlock during the callback to
-        * the daemon. Subsequent user space lookups for the same
-        * dentry are placed on the wait queue while the daemon
-        * itself is allowed passage unresticted so the create
-        * operation itself can then hash the dentry. Finally,
-        * we check for the hashed dentry and return the newly
-        * hashed dentry.
-        */
-       dentry->d_op = &autofs4_root_dentry_operations;
-
-       /*
-        * And we need to ensure that the same dentry is used for
-        * all following lookup calls until it is hashed so that
-        * the dentry flags are persistent throughout the request.
-        */
-       ino = autofs4_init_ino(NULL, sbi, 0555);
-       if (!ino)
-               return ERR_PTR(-ENOMEM);
-
-       dentry->d_fsdata = ino;
-       ino->dentry = dentry;
-
-       /*
-        * Only set the mount pending flag for new dentrys not created
-        * by the daemon.
-        */
-       if (!oz_mode)
-               ino->flags |= AUTOFS_INF_PENDING;
-
-       d_instantiate(dentry, NULL);
-
-       return ino;
-}
-
 /* Lookups in the root directory */
 static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 {
@@ -702,7 +521,6 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
        struct autofs_info *ino;
        struct dentry *expiring, *active;
        int oz_mode;
-       int status = 0;
 
        DPRINTK("name = %.*s",
                dentry->d_name.len, dentry->d_name.name);
@@ -717,26 +535,44 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
        DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
                 current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
 
-       spin_lock(&sbi->fs_lock);
        active = autofs4_lookup_active(dentry);
        if (active) {
                dentry = active;
                ino = autofs4_dentry_ino(dentry);
-               /* If this came from revalidate, rehash it */
-               autofs4_revalidate_rehash(dentry);
-               spin_unlock(&sbi->fs_lock);
        } else {
-               spin_unlock(&sbi->fs_lock);
-               ino = init_new_dentry(sbi, dentry, oz_mode);
-               if (IS_ERR(ino))
-                       return (struct dentry *) ino;
-       }
+               /*
+                * Mark the dentry incomplete but don't hash it. We do this
+                * to serialize our inode creation operations (symlink and
+                * mkdir) which prevents deadlock during the callback to
+                * the daemon. Subsequent user space lookups for the same
+                * dentry are placed on the wait queue while the daemon
+                * itself is allowed passage unresticted so the create
+                * operation itself can then hash the dentry. Finally,
+                * we check for the hashed dentry and return the newly
+                * hashed dentry.
+                */
+               dentry->d_op = &autofs4_root_dentry_operations;
+
+               /*
+                * And we need to ensure that the same dentry is used for
+                * all following lookup calls until it is hashed so that
+                * the dentry flags are persistent throughout the request.
+                */
+               ino = autofs4_init_ino(NULL, sbi, 0555);
+               if (!ino)
+                       return ERR_PTR(-ENOMEM);
 
-       autofs4_add_active(dentry);
+               dentry->d_fsdata = ino;
+               ino->dentry = dentry;
+
+               autofs4_add_active(dentry);
+
+               d_instantiate(dentry, NULL);
+       }
 
        if (!oz_mode) {
-               expiring = autofs4_lookup_expiring(dentry);
                mutex_unlock(&dir->i_mutex);
+               expiring = autofs4_lookup_expiring(dentry);
                if (expiring) {
                        /*
                         * If we are racing with expire the request might not
@@ -744,22 +580,23 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
                         * so it must have been successful, so just wait for it.
                         */
                        autofs4_expire_wait(expiring);
+                       autofs4_del_expiring(expiring);
                        dput(expiring);
                }
-               status = try_to_fill_dentry(dentry);
-               mutex_lock(&dir->i_mutex);
+
                spin_lock(&sbi->fs_lock);
-               ino->flags &= ~AUTOFS_INF_PENDING;
+               ino->flags |= AUTOFS_INF_PENDING;
                spin_unlock(&sbi->fs_lock);
+               if (dentry->d_op && dentry->d_op->d_revalidate)
+                       (dentry->d_op->d_revalidate)(dentry, nd);
+               mutex_lock(&dir->i_mutex);
        }
 
-       autofs4_del_active(dentry);
-
        /*
-        * If we had a mount fail, check if we had to handle
+        * If we are still pending, check if we had to handle
         * a signal. If so we can force a restart..
         */
-       if (status) {
+       if (ino->flags & AUTOFS_INF_PENDING) {
                /* See if we were interrupted */
                if (signal_pending(current)) {
                        sigset_t *sigset = &current->pending.signal;
@@ -771,46 +608,43 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
                            return ERR_PTR(-ERESTARTNOINTR);
                        }
                }
-       }
-
-       /*
-        * User space can (and has done in the past) remove and re-create
-        * this directory during the callback. This can leave us with an
-        * unhashed dentry, but a successful mount!  So we need to
-        * perform another cached lookup in case the dentry now exists.
-        */
-       if (!oz_mode && !have_submounts(dentry)) {
-               struct dentry *new;
-               new = d_lookup(dentry->d_parent, &dentry->d_name);
-               if (new) {
-                       if (active)
-                               dput(active);
-                       return new;
-               } else {
-                       if (!status)
-                               status = -ENOENT;
+               if (!oz_mode) {
+                       spin_lock(&sbi->fs_lock);
+                       ino->flags &= ~AUTOFS_INF_PENDING;
+                       spin_unlock(&sbi->fs_lock);
                }
        }
 
        /*
-        * If we had a mount failure, return status to user space.
-        * If the mount succeeded and we used a dentry from the active queue
-        * return it.
+        * If this dentry is unhashed, then we shouldn't honour this
+        * lookup.  Returning ENOENT here doesn't do the right thing
+        * for all system calls, but it should be OK for the operations
+        * we permit from an autofs.
         */
-       if (status) {
-               dentry = ERR_PTR(status);
-               if (active)
-                       dput(active);
-               return dentry;
-       } else {
+       if (!oz_mode && d_unhashed(dentry)) {
                /*
-                * Valid successful mount, return active dentry or NULL
-                * for a new dentry.
+                * A user space application can (and has done in the past)
+                * remove and re-create this directory during the callback.
+                * This can leave us with an unhashed dentry, but a
+                * successful mount!  So we need to perform another
+                * cached lookup in case the dentry now exists.
                 */
+               struct dentry *parent = dentry->d_parent;
+               struct dentry *new = d_lookup(parent, &dentry->d_name);
+               if (new != NULL)
+                       dentry = new;
+               else
+                       dentry = ERR_PTR(-ENOENT);
+
                if (active)
-                       return active;
+                       dput(active);
+
+               return dentry;
        }
 
+       if (active)
+               return active;
+
        return NULL;
 }
 
@@ -834,6 +668,8 @@ static int autofs4_dir_symlink(struct inode *dir,
        if (!ino)
                return -ENOMEM;
 
+       autofs4_del_active(dentry);
+
        ino->size = strlen(symname);
        cp = kmalloc(ino->size + 1, GFP_KERNEL);
        if (!cp) {
@@ -910,6 +746,7 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
        dir->i_mtime = CURRENT_TIME;
 
        spin_lock(&dcache_lock);
+       autofs4_add_expiring(dentry);
        spin_lock(&dentry->d_lock);
        __d_drop(dentry);
        spin_unlock(&dentry->d_lock);
@@ -935,6 +772,7 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
                spin_unlock(&dcache_lock);
                return -ENOTEMPTY;
        }
+       autofs4_add_expiring(dentry);
        spin_lock(&dentry->d_lock);
        __d_drop(dentry);
        spin_unlock(&dentry->d_lock);
@@ -972,6 +810,8 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
        if (!ino)
                return -ENOMEM;
 
+       autofs4_del_active(dentry);
+
        inode = autofs4_get_inode(dir->i_sb, ino);
        if (!inode) {
                if (!dentry->d_fsdata)