From: Al Viro viro@zeniv.linux.org.uk
commit 0818bf27c05b2de56c5b2bd08cfae2a939bd5f52 upstream
* switch allocation to alloc_large_system_hash() * make sizes overridable by boot parameters (mhash_entries=, mphash_entries=) * switch mountpoint_hashtable from list_head to hlist_head
Cc: stable@vger.kernel.org Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: luanshi zhangliguang@linux.alibaba.com --- 7u/fs/mount.h | 2 +- 7u/fs/namespace.c | 85 +++++++++++++++++++++++++++++++++++++++++-------------- 2 files changed, 64 insertions(+), 23 deletions(-)
diff --git a/7u/fs/mount.h b/7u/fs/mount.h index 7758dd4..75d5615 100644 --- a/7u/fs/mount.h +++ b/7u/fs/mount.h @@ -19,7 +19,7 @@ struct mnt_pcp { };
struct mountpoint { - struct list_head m_hash; + struct hlist_node m_hash; struct dentry *m_dentry; int m_count; }; diff --git a/7u/fs/namespace.c b/7u/fs/namespace.c index 76ba0d7..6e1231b 100644 --- a/7u/fs/namespace.c +++ b/7u/fs/namespace.c @@ -23,11 +23,34 @@ #include <linux/uaccess.h> #include <linux/proc_ns.h> #include <linux/magic.h> +#include <linux/bootmem.h> #include "pnode.h" #include "internal.h"
-#define HASH_SHIFT 12 -#define HASH_SIZE (1UL << HASH_SHIFT) +static unsigned int m_hash_mask __read_mostly; +static unsigned int m_hash_shift __read_mostly; +static unsigned int mp_hash_mask __read_mostly; +static unsigned int mp_hash_shift __read_mostly; + +static __initdata unsigned long mhash_entries; +static int __init set_mhash_entries(char *str) +{ + if (!str) + return 0; + mhash_entries = simple_strtoul(str, &str, 0); + return 1; +} +__setup("mhash_entries=", set_mhash_entries); + +static __initdata unsigned long mphash_entries; +static int __init set_mphash_entries(char *str) +{ + if (!str) + return 0; + mphash_entries = simple_strtoul(str, &str, 0); + return 1; +} +__setup("mphash_entries=", set_mphash_entries);
static u64 event; static DEFINE_IDA(mnt_id_ida); @@ -36,8 +59,8 @@ static DEFINE_SPINLOCK(mnt_id_lock); static int mnt_id_start = 0; static int mnt_group_start = 1;
-static struct list_head mount_hashtable[HASH_SIZE]; -static struct list_head mountpoint_hashtable[HASH_SIZE]; +static struct list_head *mount_hashtable __read_mostly; +static struct hlist_head *mountpoint_hashtable __read_mostly; static struct kmem_cache *mnt_cache __read_mostly; static struct rw_semaphore namespace_sem;
@@ -55,12 +78,19 @@ EXPORT_SYMBOL_GPL(fs_kobj); */ DEFINE_BRLOCK(vfsmount_lock);
-static inline unsigned long hash(struct vfsmount *mnt, struct dentry *dentry) +static inline struct list_head *m_hash(struct vfsmount *mnt, struct dentry *dentry) { unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES); tmp += ((unsigned long)dentry / L1_CACHE_BYTES); - tmp = tmp + (tmp >> HASH_SHIFT); - return tmp & (HASH_SIZE - 1); + tmp = tmp + (tmp >> m_hash_shift); + return &mount_hashtable[tmp & m_hash_mask]; +} + +static inline struct hlist_head *mp_hash(struct dentry *dentry) +{ + unsigned long tmp = ((unsigned long)dentry / L1_CACHE_BYTES); + tmp = tmp + (tmp >> mp_hash_shift); + return &mountpoint_hashtable[tmp & mp_hash_mask]; }
#define MNT_WRITER_UNDERFLOW_LIMIT -(1<<16) @@ -555,7 +585,7 @@ static void free_vfsmnt(struct mount *mnt) */ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) { - struct list_head *head = mount_hashtable + hash(mnt, dentry); + struct list_head *head = m_hash(mnt, dentry); struct mount *p;
list_for_each_entry(p, head, mnt_hash) @@ -570,7 +600,7 @@ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) */ struct mount *__lookup_mnt_last(struct vfsmount *mnt, struct dentry *dentry) { - struct list_head *head = mount_hashtable + hash(mnt, dentry); + struct list_head *head = m_hash(mnt, dentry); struct mount *p;
list_for_each_entry_reverse(p, head, mnt_hash) @@ -613,11 +643,11 @@ struct vfsmount *lookup_mnt(struct path *path)
static struct mountpoint *new_mountpoint(struct dentry *dentry) { - struct list_head *chain = mountpoint_hashtable + hash(NULL, dentry); + struct hlist_head *chain = mp_hash(dentry); struct mountpoint *mp; int ret;
- list_for_each_entry(mp, chain, m_hash) { + hlist_for_each_entry(mp, chain, m_hash) { if (mp->m_dentry == dentry) { /* might be worth a WARN_ON() */ if (d_unlinked(dentry)) @@ -639,7 +669,7 @@ static struct mountpoint *new_mountpoint(struct dentry *dentry)
mp->m_dentry = dentry; mp->m_count = 1; - list_add(&mp->m_hash, chain); + hlist_add_head(&mp->m_hash, chain); return mp; }
@@ -650,7 +680,7 @@ static void put_mountpoint(struct mountpoint *mp) spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_MOUNTED; spin_unlock(&dentry->d_lock); - list_del(&mp->m_hash); + hlist_del(&mp->m_hash); kfree(mp); } } @@ -719,8 +749,7 @@ static void attach_mnt(struct mount *mnt, struct mountpoint *mp) { mnt_set_mountpoint(parent, mp, mnt); - list_add_tail(&mnt->mnt_hash, mount_hashtable + - hash(&parent->mnt, mp->m_dentry)); + list_add_tail(&mnt->mnt_hash, m_hash(&parent->mnt, mp->m_dentry)); list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); }
@@ -742,8 +771,8 @@ static void commit_tree(struct mount *mnt)
list_splice(&head, n->list.prev);
- list_add_tail(&mnt->mnt_hash, mount_hashtable + - hash(&parent->mnt, mnt->mnt_mountpoint)); + list_add_tail(&mnt->mnt_hash, + m_hash(&parent->mnt, mnt->mnt_mountpoint)); list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); touch_mnt_namespace(n); } @@ -2792,12 +2821,24 @@ void __init mnt_init(void) mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount), 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
- printk(KERN_INFO "Mount-cache hash table entries: %lu\n", HASH_SIZE); - - for (u = 0; u < HASH_SIZE; u++) + mount_hashtable = alloc_large_system_hash("Mount-cache", + sizeof(struct list_head), + mhash_entries, 19, + 0, + &m_hash_shift, &m_hash_mask, 0, 0); + mountpoint_hashtable = alloc_large_system_hash("Mountpoint-cache", + sizeof(struct hlist_head), + mphash_entries, 19, + 0, + &mp_hash_shift, &mp_hash_mask, 0, 0); + + if (!mount_hashtable || !mountpoint_hashtable) + panic("Failed to allocate mount hash table\n"); + + for (u = 0; u <= m_hash_mask; u++) INIT_LIST_HEAD(&mount_hashtable[u]); - for (u = 0; u < HASH_SIZE; u++) - INIT_LIST_HEAD(&mountpoint_hashtable[u]); + for (u = 0; u <= mp_hash_mask; u++) + INIT_HLIST_HEAD(&mountpoint_hashtable[u]);
br_lock_init(&vfsmount_lock);