[XFS] Shutdown the filesystem if all device paths have gone. Made
[safe/jmp/linux-2.6] / fs / dcache.c
index e90512e..940d188 100644 (file)
@@ -34,9 +34,8 @@
 #include <linux/swap.h>
 #include <linux/bootmem.h>
 
-/* #define DCACHE_DEBUG 1 */
 
-int sysctl_vfs_cache_pressure = 100;
+int sysctl_vfs_cache_pressure __read_mostly = 100;
 EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
 
  __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
@@ -44,7 +43,7 @@ static seqlock_t rename_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
 
 EXPORT_SYMBOL(dcache_lock);
 
-static kmem_cache_t *dentry_cache
+static kmem_cache_t *dentry_cache __read_mostly;
 
 #define DNAME_INLINE_LEN (sizeof(struct dentry)-offsetof(struct dentry,d_iname))
 
@@ -59,9 +58,9 @@ static kmem_cache_t *dentry_cache;
 #define D_HASHBITS     d_hash_shift
 #define D_HASHMASK     d_hash_mask
 
-static unsigned int d_hash_mask;
-static unsigned int d_hash_shift;
-static struct hlist_head *dentry_hashtable;
+static unsigned int d_hash_mask __read_mostly;
+static unsigned int d_hash_shift __read_mostly;
+static struct hlist_head *dentry_hashtable __read_mostly;
 static LIST_HEAD(dentry_unused);
 
 /* Statistics gathering. */
@@ -71,7 +70,7 @@ struct dentry_stat_t dentry_stat = {
 
 static void d_callback(struct rcu_head *head)
 {
-       struct dentry * dentry = container_of(head, struct dentry, d_rcu);
+       struct dentry * dentry = container_of(head, struct dentry, d_u.d_rcu);
 
        if (dname_external(dentry))
                kfree(dentry->d_name.name);
@@ -86,7 +85,7 @@ static void d_free(struct dentry *dentry)
 {
        if (dentry->d_op && dentry->d_op->d_release)
                dentry->d_op->d_release(dentry);
-       call_rcu(&dentry->d_rcu, d_callback);
+       call_rcu(&dentry->d_u.d_rcu, d_callback);
 }
 
 /*
@@ -94,7 +93,7 @@ static void d_free(struct dentry *dentry)
  * d_iput() operation if defined.
  * Called with dcache_lock and per dentry lock held, drops both.
  */
-static inline void dentry_iput(struct dentry * dentry)
+static void dentry_iput(struct dentry * dentry)
 {
        struct inode *inode = dentry->d_inode;
        if (inode) {
@@ -193,7 +192,7 @@ kill_it: {
                        list_del(&dentry->d_lru);
                        dentry_stat.nr_unused--;
                }
-               list_del(&dentry->d_child);
+               list_del(&dentry->d_u.d_child);
                dentry_stat.nr_dentry--;        /* For d_free, below */
                /*drops the locks, at that point nobody can reach this dentry */
                dentry_iput(dentry);
@@ -325,10 +324,13 @@ static struct dentry * __d_find_alias(struct inode *inode, int want_discon)
 
 struct dentry * d_find_alias(struct inode *inode)
 {
-       struct dentry *de;
-       spin_lock(&dcache_lock);
-       de = __d_find_alias(inode, 0);
-       spin_unlock(&dcache_lock);
+       struct dentry *de = NULL;
+
+       if (!list_empty(&inode->i_dentry)) {
+               spin_lock(&dcache_lock);
+               de = __d_find_alias(inode, 0);
+               spin_unlock(&dcache_lock);
+       }
        return de;
 }
 
@@ -367,7 +369,7 @@ static inline void prune_one_dentry(struct dentry * dentry)
        struct dentry * parent;
 
        __d_drop(dentry);
-       list_del(&dentry->d_child);
+       list_del(&dentry->d_u.d_child);
        dentry_stat.nr_dentry--;        /* For d_free, below */
        dentry_iput(dentry);
        parent = dentry->d_parent;
@@ -486,6 +488,7 @@ repeat:
                        continue;
                }
                prune_one_dentry(dentry);
+               cond_resched_lock(&dcache_lock);
                goto repeat;
        }
        spin_unlock(&dcache_lock);
@@ -518,7 +521,7 @@ repeat:
 resume:
        while (next != &this_parent->d_subdirs) {
                struct list_head *tmp = next;
-               struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+               struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
                next = tmp->next;
                /* Have we found a mount point ? */
                if (d_mountpoint(dentry))
@@ -532,7 +535,7 @@ resume:
         * All done at this level ... ascend and resume the search.
         */
        if (this_parent != parent) {
-               next = this_parent->d_child.next; 
+               next = this_parent->d_u.d_child.next;
                this_parent = this_parent->d_parent;
                goto resume;
        }
@@ -569,7 +572,7 @@ repeat:
 resume:
        while (next != &this_parent->d_subdirs) {
                struct list_head *tmp = next;
-               struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+               struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
                next = tmp->next;
 
                if (!list_empty(&dentry->d_lru)) {
@@ -599,10 +602,6 @@ resume:
                 */
                if (!list_empty(&dentry->d_subdirs)) {
                        this_parent = dentry;
-#ifdef DCACHE_DEBUG
-printk(KERN_DEBUG "select_parent: descending to %s/%s, found=%d\n",
-dentry->d_parent->d_name.name, dentry->d_name.name, found);
-#endif
                        goto repeat;
                }
        }
@@ -610,12 +609,8 @@ dentry->d_parent->d_name.name, dentry->d_name.name, found);
         * All done at this level ... ascend and resume the search.
         */
        if (this_parent != parent) {
-               next = this_parent->d_child.next; 
+               next = this_parent->d_u.d_child.next;
                this_parent = this_parent->d_parent;
-#ifdef DCACHE_DEBUG
-printk(KERN_DEBUG "select_parent: ascending to %s/%s, found=%d\n",
-this_parent->d_parent->d_name.name, this_parent->d_name.name, found);
-#endif
                goto resume;
        }
 out:
@@ -644,7 +639,7 @@ void shrink_dcache_parent(struct dentry * parent)
  *
  * Prune the dentries that are anonymous
  *
- * parsing d_hash list does not hlist_for_each_rcu() as it
+ * parsing d_hash list does not hlist_for_each_entry_rcu() as it
  * done under dcache_lock.
  *
  */
@@ -743,7 +738,9 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
        dentry->d_op = NULL;
        dentry->d_fsdata = NULL;
        dentry->d_mounted = 0;
+#ifdef CONFIG_PROFILING
        dentry->d_cookie = NULL;
+#endif
        INIT_HLIST_NODE(&dentry->d_hash);
        INIT_LIST_HEAD(&dentry->d_lru);
        INIT_LIST_HEAD(&dentry->d_subdirs);
@@ -753,12 +750,12 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
                dentry->d_parent = dget(parent);
                dentry->d_sb = parent->d_sb;
        } else {
-               INIT_LIST_HEAD(&dentry->d_child);
+               INIT_LIST_HEAD(&dentry->d_u.d_child);
        }
 
        spin_lock(&dcache_lock);
        if (parent)
-               list_add(&dentry->d_child, &parent->d_subdirs);
+               list_add(&dentry->d_u.d_child, &parent->d_subdirs);
        dentry_stat.nr_dentry++;
        spin_unlock(&dcache_lock);
 
@@ -792,11 +789,12 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name)
  
 void d_instantiate(struct dentry *entry, struct inode * inode)
 {
-       if (!list_empty(&entry->d_alias)) BUG();
+       BUG_ON(!list_empty(&entry->d_alias));
        spin_lock(&dcache_lock);
        if (inode)
                list_add(&entry->d_alias, &inode->i_dentry);
        entry->d_inode = inode;
+       fsnotify_d_instantiate(entry, inode);
        spin_unlock(&dcache_lock);
        security_d_instantiate(entry, inode);
 }
@@ -808,10 +806,14 @@ void d_instantiate(struct dentry *entry, struct inode * inode)
  *
  * Fill in inode information in the entry. On success, it returns NULL.
  * If an unhashed alias of "entry" already exists, then we return the
- * aliased dentry instead.
+ * aliased dentry instead and drop one reference to inode.
  *
  * Note that in order to avoid conflicts with rename() etc, the caller
  * had better be holding the parent directory semaphore.
+ *
+ * This also assumes that the inode count has been incremented
+ * (or otherwise set) by the caller to indicate that it is now
+ * in use by the dcache.
  */
 struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
 {
@@ -838,11 +840,13 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
                dget_locked(alias);
                spin_unlock(&dcache_lock);
                BUG_ON(!d_unhashed(alias));
+               iput(inode);
                return alias;
        }
        list_add(&entry->d_alias, &inode->i_dentry);
 do_negative:
        entry->d_inode = inode;
+       fsnotify_d_instantiate(entry, inode);
        spin_unlock(&dcache_lock);
        security_d_instantiate(entry, inode);
        return NULL;
@@ -973,6 +977,7 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
                new = __d_find_alias(inode, 1);
                if (new) {
                        BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
+                       fsnotify_d_instantiate(new, inode);
                        spin_unlock(&dcache_lock);
                        security_d_instantiate(new, inode);
                        d_rehash(dentry);
@@ -982,6 +987,7 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
                        /* d_instantiate takes dcache_lock, so we do it by hand */
                        list_add(&dentry->d_alias, &inode->i_dentry);
                        dentry->d_inode = inode;
+                       fsnotify_d_instantiate(dentry, inode);
                        spin_unlock(&dcache_lock);
                        security_d_instantiate(dentry, inode);
                        d_rehash(dentry);
@@ -1043,15 +1049,13 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name)
        struct hlist_head *head = d_hash(parent,hash);
        struct dentry *found = NULL;
        struct hlist_node *node;
+       struct dentry *dentry;
 
        rcu_read_lock();
        
-       hlist_for_each_rcu(node, head) {
-               struct dentry *dentry; 
+       hlist_for_each_entry_rcu(dentry, node, head, d_hash) {
                struct qstr *qstr;
 
-               dentry = hlist_entry(node, struct dentry, d_hash);
-
                if (dentry->d_name.hash != hash)
                        continue;
                if (dentry->d_parent != parent)
@@ -1097,6 +1101,32 @@ next:
 }
 
 /**
+ * d_hash_and_lookup - hash the qstr then search for a dentry
+ * @dir: Directory to search in
+ * @name: qstr of name we wish to find
+ *
+ * On hash failure or on lookup failure NULL is returned.
+ */
+struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
+{
+       struct dentry *dentry = NULL;
+
+       /*
+        * Check for a fs-specific hash function. Note that we must
+        * calculate the standard hash first, as the d_op->d_hash()
+        * routine may choose to leave the hash value unchanged.
+        */
+       name->hash = full_name_hash(name->name, name->len);
+       if (dir->d_op && dir->d_op->d_hash) {
+               if (dir->d_op->d_hash(dir, name) < 0)
+                       goto out;
+       }
+       dentry = d_lookup(dir, name);
+out:
+       return dentry;
+}
+
+/**
  * d_validate - verify dentry provided from insecure source
  * @dentry: The dentry alleged to be valid child of @dparent
  * @dparent: The parent dentry (known to be valid)
@@ -1123,7 +1153,7 @@ int d_validate(struct dentry *dentry, struct dentry *dparent)
        spin_lock(&dcache_lock);
        base = d_hash(dparent, dentry->d_name.hash);
        hlist_for_each(lhp,base) { 
-               /* hlist_for_each_rcu() not required for d_hash list
+               /* hlist_for_each_entry_rcu() not required for d_hash list
                 * as it is parsed under dcache_lock
                 */
                if (dentry == hlist_entry(lhp, struct dentry, d_hash)) {
@@ -1170,6 +1200,9 @@ void d_delete(struct dentry * dentry)
        if (atomic_read(&dentry->d_count) == 1) {
                dentry_iput(dentry);
                fsnotify_nameremove(dentry, isdir);
+
+               /* remove this and other inotify debug checks after 2.6.18 */
+               dentry->d_flags &= ~DCACHE_INOTIFY_PARENT_WATCHED;
                return;
        }
 
@@ -1312,8 +1345,8 @@ already_unhashed:
        /* Unhash the target: dput() will then get rid of it */
        __d_drop(target);
 
-       list_del(&dentry->d_child);
-       list_del(&target->d_child);
+       list_del(&dentry->d_u.d_child);
+       list_del(&target->d_u.d_child);
 
        /* Switch the names.. */
        switch_names(dentry, target);
@@ -1324,16 +1357,17 @@ already_unhashed:
        if (IS_ROOT(dentry)) {
                dentry->d_parent = target->d_parent;
                target->d_parent = target;
-               INIT_LIST_HEAD(&target->d_child);
+               INIT_LIST_HEAD(&target->d_u.d_child);
        } else {
                do_switch(dentry->d_parent, target->d_parent);
 
                /* And add them back to the (new) parent lists */
-               list_add(&target->d_child, &target->d_parent->d_subdirs);
+               list_add(&target->d_u.d_child, &target->d_parent->d_subdirs);
        }
 
-       list_add(&dentry->d_child, &dentry->d_parent->d_subdirs);
+       list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
        spin_unlock(&target->d_lock);
+       fsnotify_d_move(dentry);
        spin_unlock(&dentry->d_lock);
        write_sequnlock(&rename_lock);
        spin_unlock(&dcache_lock);
@@ -1570,7 +1604,7 @@ repeat:
 resume:
        while (next != &this_parent->d_subdirs) {
                struct list_head *tmp = next;
-               struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+               struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
                next = tmp->next;
                if (d_unhashed(dentry)||!dentry->d_inode)
                        continue;
@@ -1581,7 +1615,7 @@ resume:
                atomic_dec(&dentry->d_count);
        }
        if (this_parent != root) {
-               next = this_parent->d_child.next; 
+               next = this_parent->d_u.d_child.next;
                atomic_dec(&this_parent->d_count);
                this_parent = this_parent->d_parent;
                goto resume;
@@ -1608,26 +1642,12 @@ ino_t find_inode_number(struct dentry *dir, struct qstr *name)
        struct dentry * dentry;
        ino_t ino = 0;
 
-       /*
-        * Check for a fs-specific hash function. Note that we must
-        * calculate the standard hash first, as the d_op->d_hash()
-        * routine may choose to leave the hash value unchanged.
-        */
-       name->hash = full_name_hash(name->name, name->len);
-       if (dir->d_op && dir->d_op->d_hash)
-       {
-               if (dir->d_op->d_hash(dir, name) != 0)
-                       goto out;
-       }
-
-       dentry = d_lookup(dir, name);
-       if (dentry)
-       {
+       dentry = d_hash_and_lookup(dir, name);
+       if (dentry) {
                if (dentry->d_inode)
                        ino = dentry->d_inode->i_ino;
                dput(dentry);
        }
-out:
        return ino;
 }
 
@@ -1677,7 +1697,8 @@ static void __init dcache_init(unsigned long mempages)
        dentry_cache = kmem_cache_create("dentry_cache",
                                         sizeof(struct dentry),
                                         0,
-                                        SLAB_RECLAIM_ACCOUNT|SLAB_PANIC,
+                                        (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
+                                        SLAB_MEM_SPREAD),
                                         NULL, NULL);
        
        set_shrinker(DEFAULT_SEEKS, shrink_dcache_memory);
@@ -1701,10 +1722,10 @@ static void __init dcache_init(unsigned long mempages)
 }
 
 /* SLAB cache for __getname() consumers */
-kmem_cache_t *names_cachep;
+kmem_cache_t *names_cachep __read_mostly;
 
 /* SLAB cache for file structures */
-kmem_cache_t *filp_cachep;
+kmem_cache_t *filp_cachep __read_mostly;
 
 EXPORT_SYMBOL(d_genocide);
 
@@ -1731,7 +1752,7 @@ void __init vfs_caches_init(unsigned long mempages)
                        SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
 
        filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
-                       SLAB_HWCACHE_ALIGN|SLAB_PANIC, filp_ctor, filp_dtor);
+                       SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
 
        dcache_init(mempages);
        inode_init(mempages);