From 3070568fd7cb7123650ca2cdddf932520f6d71df Mon Sep 17 00:00:00 2001 From: =?utf8?q?S=2E=C3=87a=C4=9Flar=20Onur?= Date: Thu, 29 Apr 2010 20:00:29 +0000 Subject: [PATCH] add linux-2.6-590-dcookies-mm.patch --- kernel.spec | 4 +- linux-2.6-590-dcookies-mm.patch | 246 ++++++++++++++++++++++++++++++++ 2 files changed, 248 insertions(+), 2 deletions(-) create mode 100644 linux-2.6-590-dcookies-mm.patch diff --git a/kernel.spec b/kernel.spec index 2900f392d..8a4a453b6 100644 --- a/kernel.spec +++ b/kernel.spec @@ -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 index 000000000..e7b6df2b1 --- /dev/null +++ b/linux-2.6-590-dcookies-mm.patch @@ -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 + #include + #include ++#include + #include + + /* 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) -- 2.43.0