add linux-2.6-590-dcookies-mm.patch
S.Çağlar Onur [Thu, 29 Apr 2010 20:00:29 +0000 (20:00 +0000)]
kernel.spec
linux-2.6-590-dcookies-mm.patch [new file with mode: 0644]

index 2900f39..8a4a453 100644 (file)
@@ -1870,8 +1870,8 @@ Patch90530: linux-2.6-530-built-by-support.patch
 Patch90550: linux-2.6-550-raise-default-nfile-ulimit.patch
 Patch90570:  linux-2.6-570-tagxid.patch
 Patch90580:  linux-2.6-580-show-proc-virt.patch
+Patch90590:  linux-2.6-590-dcookies-mm.patch
 #
-#Patch90590:  linux-2.6-590-dcookies-mm.patch
 #Patch90591:  linux-2.6-591-chopstix-intern.patch
 #
 Patch90640:  linux-2.6-640-netlink-audit-hack.patch
@@ -3517,8 +3517,8 @@ ApplyPatch linux-2.6-530-built-by-support.patch
 ApplyPatch linux-2.6-550-raise-default-nfile-ulimit.patch
 ApplyPatch linux-2.6-570-tagxid.patch
 ApplyPatch linux-2.6-580-show-proc-virt.patch
+ApplyPatch linux-2.6-590-dcookies-mm.patch
 #
-#ApplyPatch linux-2.6-590-dcookies-mm.patch
 #ApplyPatch linux-2.6-591-chopstix-intern.patch
 #
 ApplyPatch linux-2.6-640-netlink-audit-hack.patch
diff --git a/linux-2.6-590-dcookies-mm.patch b/linux-2.6-590-dcookies-mm.patch
new file mode 100644 (file)
index 0000000..e7b6df2
--- /dev/null
@@ -0,0 +1,246 @@
+diff --git a/fs/dcookies.c b/fs/dcookies.c
+index a21cabd..1e95c94 100644
+--- a/fs/dcookies.c
++++ b/fs/dcookies.c
+@@ -25,6 +25,7 @@
+ #include <linux/dcookies.h>
+ #include <linux/mutex.h>
+ #include <linux/path.h>
++#include <linux/spinlock.h>
+ #include <asm/uaccess.h>
+ /* The dcookies are allocated from a kmem_cache and
+@@ -38,15 +39,21 @@ struct dcookie_struct {
+ static LIST_HEAD(dcookie_users);
+ static DEFINE_MUTEX(dcookie_mutex);
++spinlock_t dcookie_hash_write_lock = SPIN_LOCK_UNLOCKED;
+ static struct kmem_cache *dcookie_cache __read_mostly;
+-static struct list_head *dcookie_hashtable __read_mostly;
++static struct list_head *dcookie_hashtable[3] __read_mostly;
+ static size_t hash_size __read_mostly;
++unsigned int current_hash = 1, old_hash = 0;
+ static inline int is_live(void)
+ {
+       return !(list_empty(&dcookie_users));
+ }
++static inline int is_shared(void)
++{
++      return !(list_empty(&dcookie_users)) && !(list_empty(dcookie_users.next));
++}
+ /* The dentry is locked, its address will do for the cookie */
+ static inline unsigned long dcookie_value(struct dcookie_struct * dcs)
+@@ -68,7 +75,7 @@ static struct dcookie_struct * find_dcookie(unsigned long dcookie)
+       struct list_head * pos;
+       struct list_head * list;
+-      list = dcookie_hashtable + dcookie_hash(dcookie);
++      list = dcookie_hashtable[current_hash] + dcookie_hash(dcookie);
+       list_for_each(pos, list) {
+               dcs = list_entry(pos, struct dcookie_struct, hash_list);
+@@ -78,21 +85,33 @@ static struct dcookie_struct * find_dcookie(unsigned long dcookie)
+               }
+       }
++      if (!found) {
++              list = dcookie_hashtable[old_hash] + dcookie_hash(dcookie);
++
++              list_for_each(pos, list) {
++                      dcs = list_entry(pos, struct dcookie_struct, hash_list);
++                      if (dcookie_value(dcs) == dcookie) {
++                              found = dcs;
++                              break;
++                      }
++              }
++      }
++
+       return found;
+ }
+ static void hash_dcookie(struct dcookie_struct * dcs)
+ {
+-      struct list_head * list = dcookie_hashtable + dcookie_hash(dcookie_value(dcs));
++      struct list_head * list = dcookie_hashtable[current_hash] + dcookie_hash(dcookie_value(dcs));
+       list_add(&dcs->hash_list, list);
+ }
+ static struct dcookie_struct *alloc_dcookie(struct path *path)
+ {
+-      struct dcookie_struct *dcs = kmem_cache_alloc(dcookie_cache,
+-                                                      GFP_KERNEL);
++      struct dcookie_struct *dcs = kmem_cache_alloc(dcookie_cache, GFP_ATOMIC);
++      
+       struct dentry *d;
+       if (!dcs)
+               return NULL;
+@@ -117,7 +136,7 @@ int get_dcookie(struct path *path, unsigned long *cookie)
+       int err = 0;
+       struct dcookie_struct * dcs;
+-      mutex_lock(&dcookie_mutex);
++      spin_lock(&dcookie_hash_write_lock);
+       if (!is_live()) {
+               err = -EINVAL;
+@@ -137,7 +156,7 @@ int get_dcookie(struct path *path, unsigned long *cookie)
+       *cookie = dcookie_value(dcs);
+ out:
+-      mutex_unlock(&dcookie_mutex);
++      spin_unlock(&dcookie_hash_write_lock);
+       return err;
+ }
+@@ -209,7 +228,7 @@ SYSCALL_ALIAS(sys_lookup_dcookie, SyS_lookup_dcookie);
+ static int dcookie_init(void)
+ {
+       struct list_head * d;
+-      unsigned int i, hash_bits;
++      unsigned int i, j, hash_bits;
+       int err = -ENOMEM;
+       dcookie_cache = kmem_cache_create("dcookie_cache",
+@@ -219,9 +238,11 @@ static int dcookie_init(void)
+       if (!dcookie_cache)
+               goto out;
+-      dcookie_hashtable = kmalloc(PAGE_SIZE, GFP_KERNEL);
+-      if (!dcookie_hashtable)
++      for (i=0; i<3; i++) {
++              dcookie_hashtable[i] = kmalloc(PAGE_SIZE, GFP_KERNEL);
++              if (!dcookie_hashtable[i])
+               goto out_kmem;
++      }
+       err = 0;
+@@ -244,13 +265,15 @@ static int dcookie_init(void)
+       hash_size = 1UL << hash_bits;
+       /* And initialize the newly allocated array */
+-      d = dcookie_hashtable;
+-      i = hash_size;
++      for (i=0; i<3; i++) {
++              d = dcookie_hashtable[i];
++              j = hash_size;
+       do {
+               INIT_LIST_HEAD(d);
+               d++;
+-              i--;
+-      } while (i);
++              j--;
++              } while (j);
++      }
+ out:
+       return err;
+@@ -272,17 +295,31 @@ static void free_dcookie(struct dcookie_struct * dcs)
+       kmem_cache_free(dcookie_cache, dcs);
+ }
++int dcookie_swap(void) {
++      if (is_shared())
++              return -EAGAIN;
++      
++      old_hash=current_hash;
++      current_hash = (current_hash + 1) % 3;
++      return 0;
++}
+-static void dcookie_exit(void)
+-{
++/* Switch to the second hash */
++int dcookie_garbage_collect(void) {
+       struct list_head * list;
+       struct list_head * pos;
+       struct list_head * pos2;
+       struct dcookie_struct * dcs;
+       size_t i;
++      
++      int next_hash=(current_hash + 1) % 3;
++      
++      if (is_shared())
++              return -EAGAIN;
++      /* XXX consider the consequence of dcookie allocation concurring with this cleanup */
+       for (i = 0; i < hash_size; ++i) {
+-              list = dcookie_hashtable + i;
++              list = dcookie_hashtable[next_hash] + i;
+               list_for_each_safe(pos, pos2, list) {
+                       dcs = list_entry(pos, struct dcookie_struct, hash_list);
+                       list_del(&dcs->hash_list);
+@@ -290,7 +327,29 @@ static void dcookie_exit(void)
+               }
+       }
+-      kfree(dcookie_hashtable);
++      return 0;
++}
++
++static void dcookie_exit(void)
++{
++      struct list_head * list;
++      struct list_head * pos;
++      struct list_head * pos2;
++      struct dcookie_struct * dcs;
++      size_t j;
++      unsigned int i;
++
++      for (i = 0; i < 3; ++i) {
++              for (j = 0; j < hash_size; ++j) {
++                      list = dcookie_hashtable[i] + j;
++                      list_for_each_safe(pos, pos2, list) {
++                              dcs = list_entry(pos, struct dcookie_struct, hash_list);
++                              list_del(&dcs->hash_list);
++                              free_dcookie(dcs);
++                      }
++              }
++              kfree(dcookie_hashtable[i]);
++      }
+       kmem_cache_destroy(dcookie_cache);
+ }
+@@ -340,3 +399,5 @@ void dcookie_unregister(struct dcookie_user * user)
+ EXPORT_SYMBOL_GPL(dcookie_register);
+ EXPORT_SYMBOL_GPL(dcookie_unregister);
+ EXPORT_SYMBOL_GPL(get_dcookie);
++EXPORT_SYMBOL_GPL(dcookie_garbage_collect);
++EXPORT_SYMBOL_GPL(dcookie_swap);
+diff --git a/include/linux/dcookies.h b/include/linux/dcookies.h
+index 24c806f..3c1d2b2 100644
+--- a/include/linux/dcookies.h
++++ b/include/linux/dcookies.h
+@@ -46,6 +46,27 @@ void dcookie_unregister(struct dcookie_user * user);
+  */
+ int get_dcookie(struct path *path, unsigned long *cookie);
++/**
++ * dcookie_swap - switch to the next dcookie epoch
++ *
++ * Deactivate the current dcookie hash table and activate
++ * the next one
++ *
++ * Returns 0 on success
++ */
++
++int dcookie_swap(void);
++
++/**
++ * dcookie_garbage_collect - clear the hash table next in line
++ *
++ * Clear the hash table to be activated in the next epoch.
++ *
++ * Returns 0 on success
++ */
++
++int dcookie_garbage_collect(void);
++
+ #else
+ static inline struct dcookie_user * dcookie_register(void)