Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin

* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...

20 files changed, 586 insertions, 203 deletions

diff --git a/include/linux/bit_spinlock.h b/include/linux/bit_spinlock.h
index 7113a32a86ea..e612575a2596 100644
--- a/include/linux/bit_spinlock.h
+++ b/include/linux/bit_spinlock.h
@@ -1,6 +1,10 @@
 #ifndef __LINUX_BIT_SPINLOCK_H
 #define __LINUX_BIT_SPINLOCK_H
 
+#include <linux/kernel.h>
+#include <linux/preempt.h>
+#include <asm/atomic.h>
+
 /*
  *  bit-based spin_lock()
  *
diff --git a/include/linux/coda_linux.h b/include/linux/coda_linux.h
index 2e914d0771b9..4ccc59c1ea82 100644
--- a/include/linux/coda_linux.h
+++ b/include/linux/coda_linux.h
@@ -37,7 +37,7 @@ extern const struct file_operations coda_ioctl_operations;
 /* operations shared over more than one file */
 int coda_open(struct inode *i, struct file *f);
 int coda_release(struct inode *i, struct file *f);
-int coda_permission(struct inode *inode, int mask);
+int coda_permission(struct inode *inode, int mask, unsigned int flags);
 int coda_revalidate_inode(struct dentry *);
 int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 int coda_setattr(struct dentry *, struct iattr *);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 6a4aea30aa09..bd07758943e0 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -4,7 +4,9 @@
 #include <asm/atomic.h>
 #include <linux/list.h>
 #include <linux/rculist.h>
+#include <linux/rculist_bl.h>
 #include <linux/spinlock.h>
+#include <linux/seqlock.h>
 #include <linux/cache.h>
 #include <linux/rcupdate.h>
 
@@ -45,6 +47,27 @@ struct dentry_stat_t {
 };
 extern struct dentry_stat_t dentry_stat;
 
+/*
+ * Compare 2 name strings, return 0 if they match, otherwise non-zero.
+ * The strings are both count bytes long, and count is non-zero.
+ */
+static inline int dentry_cmp(const unsigned char *cs, size_t scount,
+                                const unsigned char *ct, size_t tcount)
+{
+        int ret;
+        if (scount != tcount)
+                return 1;
+        do {
+                ret = (*cs != *ct);
+                if (ret)
+                        break;
+                cs++;
+                ct++;
+                tcount--;
+        } while (tcount);
+        return ret;
+}
+
 /* Name hashing routines. Initial hash value */
 /* Hash courtesy of the R5 hash in reiserfs modulo sign bits */
 #define init_name_hash()                0
@@ -81,25 +104,33 @@ full_name_hash(const unsigned char *name, unsigned int len)
  * large memory footprint increase).
  */
 #ifdef CONFIG_64BIT
-#define DNAME_INLINE_LEN_MIN 32 /* 192 bytes */
+# define DNAME_INLINE_LEN 32 /* 192 bytes */
 #else
-#define DNAME_INLINE_LEN_MIN 40 /* 128 bytes */
+# ifdef CONFIG_SMP
+#  define DNAME_INLINE_LEN 36 /* 128 bytes */
+# else
+#  define DNAME_INLINE_LEN 40 /* 128 bytes */
+# endif
 #endif
 
 struct dentry {
-        atomic_t d_count;
+        /* RCU lookup touched fields */
         unsigned int d_flags;           /* protected by d_lock */
-        spinlock_t d_lock;              /* per dentry lock */
-        int d_mounted;
-        struct inode *d_inode;          /* Where the name belongs to - NULL is
-                                         * negative */
-        /*
-         * The next three fields are touched by __d_lookup.  Place them here
-         * so they all fit in a cache line.
-         */
-        struct hlist_node d_hash;       /* lookup hash list */
+        seqcount_t d_seq;               /* per dentry seqlock */
+        struct hlist_bl_node d_hash;    /* lookup hash list */
         struct dentry *d_parent;        /* parent directory */
         struct qstr d_name;
+        struct inode *d_inode;          /* Where the name belongs to - NULL is
+                                         * negative */
+        unsigned char d_iname[DNAME_INLINE_LEN];        /* small names */
+
+        /* Ref lookup also touches following */
+        unsigned int d_count;           /* protected by d_lock */
+        spinlock_t d_lock;              /* per dentry lock */
+        const struct dentry_operations *d_op;
+        struct super_block *d_sb;       /* The root of the dentry tree */
+        unsigned long d_time;           /* used by d_revalidate */
+        void *d_fsdata;                 /* fs-specific data */
 
         struct list_head d_lru;         /* LRU list */
         /*
@@ -111,12 +142,6 @@ struct dentry {
         } d_u;
         struct list_head d_subdirs;     /* our children */
         struct list_head d_alias;       /* inode alias list */
-        unsigned long d_time;           /* used by d_revalidate */
-        const struct dentry_operations *d_op;
-        struct super_block *d_sb;       /* The root of the dentry tree */
-        void *d_fsdata;                 /* fs-specific data */
-
-        unsigned char d_iname[DNAME_INLINE_LEN_MIN];    /* small names */
 };
 
 /*
@@ -133,96 +158,61 @@ enum dentry_d_lock_class
 
 struct dentry_operations {
         int (*d_revalidate)(struct dentry *, struct nameidata *);
-        int (*d_hash) (struct dentry *, struct qstr *);
-        int (*d_compare) (struct dentry *, struct qstr *, struct qstr *);
-        int (*d_delete)(struct dentry *);
+        int (*d_hash)(const struct dentry *, const struct inode *,
+                        struct qstr *);
+        int (*d_compare)(const struct dentry *, const struct inode *,
+                        const struct dentry *, const struct inode *,
+                        unsigned int, const char *, const struct qstr *);
+        int (*d_delete)(const struct dentry *);
         void (*d_release)(struct dentry *);
         void (*d_iput)(struct dentry *, struct inode *);
         char *(*d_dname)(struct dentry *, char *, int);
-};
-
-/* the dentry parameter passed to d_hash and d_compare is the parent
- * directory of the entries to be compared. It is used in case these
- * functions need any directory specific information for determining
- * equivalency classes.  Using the dentry itself might not work, as it
- * might be a negative dentry which has no information associated with
- * it */
+} ____cacheline_aligned;
 
 /*
-locking rules:
-                big lock        dcache_lock     d_lock   may block
-d_revalidate:   no              no              no       yes
-d_hash          no              no              no       yes
-d_compare:      no              yes             yes      no
-d_delete:       no              yes             no       no
-d_release:      no              no              no       yes
-d_iput:         no              no              no       yes
+ * Locking rules for dentry_operations callbacks are to be found in
+ * Documentation/filesystems/Locking. Keep it updated!
+ *
+ * FUrther descriptions are found in Documentation/filesystems/vfs.txt.
+ * Keep it updated too!
  */
 
 /* d_flags entries */
 #define DCACHE_AUTOFS_PENDING 0x0001    /* autofs: "under construction" */
-#define DCACHE_NFSFS_RENAMED  0x0002    /* this dentry has been "silly
-                                         * renamed" and has to be
-                                         * deleted on the last dput()
-                                         */
-#define DCACHE_DISCONNECTED 0x0004
-     /* This dentry is possibly not currently connected to the dcache tree,
-      * in which case its parent will either be itself, or will have this
-      * flag as well.  nfsd will not use a dentry with this bit set, but will
-      * first endeavour to clear the bit either by discovering that it is
-      * connected, or by performing lookup operations.   Any filesystem which
-      * supports nfsd_operations MUST have a lookup function which, if it finds
-      * a directory inode with a DCACHE_DISCONNECTED dentry, will d_move
-      * that dentry into place and return that dentry rather than the passed one,
-      * typically using d_splice_alias.
-      */
+#define DCACHE_NFSFS_RENAMED  0x0002
+     /* this dentry has been "silly renamed" and has to be deleted on the last
+      * dput() */
+
+#define DCACHE_DISCONNECTED     0x0004
+     /* This dentry is possibly not currently connected to the dcache tree, in
+      * which case its parent will either be itself, or will have this flag as
+      * well.  nfsd will not use a dentry with this bit set, but will first
+      * endeavour to clear the bit either by discovering that it is connected,
+      * or by performing lookup operations.   Any filesystem which supports
+      * nfsd_operations MUST have a lookup function which, if it finds a
+      * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that
+      * dentry into place and return that dentry rather than the passed one,
+      * typically using d_splice_alias. */
 
 #define DCACHE_REFERENCED       0x0008  /* Recently used, don't discard. */
 #define DCACHE_UNHASHED         0x0010  
-
-#define DCACHE_INOTIFY_PARENT_WATCHED   0x0020 /* Parent inode is watched by inotify */
+#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020
+     /* Parent inode is watched by inotify */
 
 #define DCACHE_COOKIE           0x0040  /* For use by dcookie subsystem */
-
-#define DCACHE_FSNOTIFY_PARENT_WATCHED  0x0080 /* Parent inode is watched by some fsnotify listener */
+#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080
+     /* Parent inode is watched by some fsnotify listener */
 
 #define DCACHE_CANT_MOUNT       0x0100
+#define DCACHE_GENOCIDE         0x0200
+#define DCACHE_MOUNTED          0x0400  /* is a mountpoint */
 
-extern spinlock_t dcache_lock;
-extern seqlock_t rename_lock;
-
-/**
- * d_drop - drop a dentry
- * @dentry: dentry to drop
- *
- * d_drop() unhashes the entry from the parent dentry hashes, so that it won't
- * be found through a VFS lookup any more. Note that this is different from
- * deleting the dentry - d_delete will try to mark the dentry negative if
- * possible, giving a successful _negative_ lookup, while d_drop will
- * just make the cache lookup fail.
- *
- * d_drop() is used mainly for stuff that wants to invalidate a dentry for some
- * reason (NFS timeouts or autofs deletes).
- *
- * __d_drop requires dentry->d_lock.
- */
-
-static inline void __d_drop(struct dentry *dentry)
-{
-        if (!(dentry->d_flags & DCACHE_UNHASHED)) {
-                dentry->d_flags |= DCACHE_UNHASHED;
-                hlist_del_rcu(&dentry->d_hash);
-        }
-}
+#define DCACHE_OP_HASH          0x1000
+#define DCACHE_OP_COMPARE       0x2000
+#define DCACHE_OP_REVALIDATE    0x4000
+#define DCACHE_OP_DELETE        0x8000
 
-static inline void d_drop(struct dentry *dentry)
-{
-        spin_lock(&dcache_lock);
-        spin_lock(&dentry->d_lock);
-        __d_drop(dentry);
-        spin_unlock(&dentry->d_lock);
-        spin_unlock(&dcache_lock);
-}
+extern seqlock_t rename_lock;
 
 static inline int dname_external(struct dentry *dentry)
 {
@@ -235,10 +225,14 @@ static inline int dname_external(struct dentry *dentry)
 extern void d_instantiate(struct dentry *, struct inode *);
 extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
 extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
+extern void __d_drop(struct dentry *dentry);
+extern void d_drop(struct dentry *dentry);
 extern void d_delete(struct dentry *);
+extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
 
 /* allocate/de-allocate */
 extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
+extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
 extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
 extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
 extern struct dentry * d_obtain_alias(struct inode *);
@@ -296,14 +290,40 @@ static inline struct dentry *d_add_unique(struct dentry *entry, struct inode *in
         return res;
 }
 
+extern void dentry_update_name_case(struct dentry *, struct qstr *);
+
 /* used for rename() and baskets */
 extern void d_move(struct dentry *, struct dentry *);
 extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
 
 /* appendix may either be NULL or be used for transname suffixes */
-extern struct dentry * d_lookup(struct dentry *, struct qstr *);
-extern struct dentry * __d_lookup(struct dentry *, struct qstr *);
-extern struct dentry * d_hash_and_lookup(struct dentry *, struct qstr *);
+extern struct dentry *d_lookup(struct dentry *, struct qstr *);
+extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
+extern struct dentry *__d_lookup(struct dentry *, struct qstr *);
+extern struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
+                                unsigned *seq, struct inode **inode);
+
+/**
+ * __d_rcu_to_refcount - take a refcount on dentry if sequence check is ok
+ * @dentry: dentry to take a ref on
+ * @seq: seqcount to verify against
+ * @Returns: 0 on failure, else 1.
+ *
+ * __d_rcu_to_refcount operates on a dentry,seq pair that was returned
+ * by __d_lookup_rcu, to get a reference on an rcu-walk dentry.
+ */
+static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
+{
+        int ret = 0;
+
+        assert_spin_locked(&dentry->d_lock);
+        if (!read_seqcount_retry(&dentry->d_seq, seq)) {
+                ret = 1;
+                dentry->d_count++;
+        }
+
+        return ret;
+}
 
 /* validate "insecure" dentry pointer */
 extern int d_validate(struct dentry *, struct dentry *);
@@ -316,34 +336,37 @@ extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
 extern char *__d_path(const struct path *path, struct path *root, char *, int);
 extern char *d_path(const struct path *, char *, int);
 extern char *d_path_with_unreachable(const struct path *, char *, int);
-extern char *__dentry_path(struct dentry *, char *, int);
+extern char *dentry_path_raw(struct dentry *, char *, int);
 extern char *dentry_path(struct dentry *, char *, int);
 
 /* Allocation counts.. */
 
 /**
- *      dget, dget_locked       -       get a reference to a dentry
+ *      dget, dget_dlock -      get a reference to a dentry
  *      @dentry: dentry to get a reference to
  *
  *      Given a dentry or %NULL pointer increment the reference count
  *      if appropriate and return the dentry. A dentry will not be 
- *      destroyed when it has references. dget() should never be
- *      called for dentries with zero reference counter. For these cases
- *      (preferably none, functions in dcache.c are sufficient for normal
- *      needs and they take necessary precautions) you should hold dcache_lock
- *      and call dget_locked() instead of dget().
+ *      destroyed when it has references.
  */
- 
+static inline struct dentry *dget_dlock(struct dentry *dentry)
+{
+        if (dentry)
+                dentry->d_count++;
+        return dentry;
+}
+
 static inline struct dentry *dget(struct dentry *dentry)
 {
         if (dentry) {
-                BUG_ON(!atomic_read(&dentry->d_count));
-                atomic_inc(&dentry->d_count);
+                spin_lock(&dentry->d_lock);
+                dget_dlock(dentry);
+                spin_unlock(&dentry->d_lock);
         }
         return dentry;
 }
 
-extern struct dentry * dget_locked(struct dentry *);
+extern struct dentry *dget_parent(struct dentry *dentry);
 
 /**
  *      d_unhashed -    is dentry hashed
@@ -374,21 +397,11 @@ static inline void dont_mount(struct dentry *dentry)
         spin_unlock(&dentry->d_lock);
 }
 
-static inline struct dentry *dget_parent(struct dentry *dentry)
-{
-        struct dentry *ret;
-
-        spin_lock(&dentry->d_lock);
-        ret = dget(dentry->d_parent);
-        spin_unlock(&dentry->d_lock);
-        return ret;
-}
-
 extern void dput(struct dentry *);
 
 static inline int d_mountpoint(struct dentry *dentry)
 {
-        return dentry->d_mounted;
+        return dentry->d_flags & DCACHE_MOUNTED;
 }
 
 extern struct vfsmount *lookup_mnt(struct path *);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 090f0eacde29..baf3e556ff0e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -392,6 +392,7 @@ struct inodes_stat_t {
 #include <linux/capability.h>
 #include <linux/semaphore.h>
 #include <linux/fiemap.h>
+#include <linux/rculist_bl.h>
 
 #include <asm/atomic.h>
 #include <asm/byteorder.h>
@@ -733,16 +734,31 @@ struct posix_acl;
 #define ACL_NOT_CACHED ((void *)(-1))
 
 struct inode {
+        /* RCU path lookup touches following: */
+        umode_t                 i_mode;
+        uid_t                   i_uid;
+        gid_t                   i_gid;
+        const struct inode_operations   *i_op;
+        struct super_block      *i_sb;
+
+        spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
+        unsigned int            i_flags;
+        struct mutex            i_mutex;
+
+        unsigned long           i_state;
+        unsigned long           dirtied_when;   /* jiffies of first dirtying */
+
         struct hlist_node       i_hash;
         struct list_head        i_wb_list;      /* backing dev IO list */
         struct list_head        i_lru;          /* inode LRU list */
         struct list_head        i_sb_list;
-        struct list_head        i_dentry;
+        union {
+                struct list_head        i_dentry;
+                struct rcu_head         i_rcu;
+        };
         unsigned long           i_ino;
         atomic_t                i_count;
         unsigned int            i_nlink;
-        uid_t                   i_uid;
-        gid_t                   i_gid;
         dev_t                   i_rdev;
         unsigned int            i_blkbits;
         u64                     i_version;
@@ -755,13 +771,8 @@ struct inode {
         struct timespec         i_ctime;
         blkcnt_t                i_blocks;
         unsigned short          i_bytes;
-        umode_t                 i_mode;
-        spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
-        struct mutex            i_mutex;
         struct rw_semaphore     i_alloc_sem;
-        const struct inode_operations   *i_op;
         const struct file_operations    *i_fop; /* former ->i_op->default_file_ops */
-        struct super_block      *i_sb;
         struct file_lock        *i_flock;
         struct address_space    *i_mapping;
         struct address_space    i_data;
@@ -782,11 +793,6 @@ struct inode {
         struct hlist_head       i_fsnotify_marks;
 #endif
 
-        unsigned long           i_state;
-        unsigned long           dirtied_when;   /* jiffies of first dirtying */
-
-        unsigned int            i_flags;
-
 #ifdef CONFIG_IMA
         /* protected by i_lock */
         unsigned int            i_readcount; /* struct files open RO */
@@ -1372,13 +1378,13 @@ struct super_block {
         const struct xattr_handler **s_xattr;
 
         struct list_head        s_inodes;       /* all inodes */
-        struct hlist_head       s_anon;         /* anonymous dentries for (nfs) exporting */
+        struct hlist_bl_head    s_anon;         /* anonymous dentries for (nfs) exporting */
 #ifdef CONFIG_SMP
         struct list_head __percpu *s_files;
 #else
         struct list_head        s_files;
 #endif
-        /* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */
+        /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
         struct list_head        s_dentry_lru;   /* unused dentry lru */
         int                     s_nr_dentry_unused;     /* # of dentry on lru */
 
@@ -1545,9 +1551,18 @@ struct file_operations {
         int (*setlease)(struct file *, long, struct file_lock **);
 };
 
+#define IPERM_FLAG_RCU  0x0001
+
 struct inode_operations {
-        int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
         struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
+        void * (*follow_link) (struct dentry *, struct nameidata *);
+        int (*permission) (struct inode *, int, unsigned int);
+        int (*check_acl)(struct inode *, int, unsigned int);
+
+        int (*readlink) (struct dentry *, char __user *,int);
+        void (*put_link) (struct dentry *, struct nameidata *, void *);
+
+        int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
         int (*link) (struct dentry *,struct inode *,struct dentry *);
         int (*unlink) (struct inode *,struct dentry *);
         int (*symlink) (struct inode *,struct dentry *,const char *);
@@ -1556,12 +1571,7 @@ struct inode_operations {
         int (*mknod) (struct inode *,struct dentry *,int,dev_t);
         int (*rename) (struct inode *, struct dentry *,
                         struct inode *, struct dentry *);
-        int (*readlink) (struct dentry *, char __user *,int);
-        void * (*follow_link) (struct dentry *, struct nameidata *);
-        void (*put_link) (struct dentry *, struct nameidata *, void *);
         void (*truncate) (struct inode *);
-        int (*permission) (struct inode *, int);
-        int (*check_acl)(struct inode *, int);
         int (*setattr) (struct dentry *, struct iattr *);
         int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
         int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
@@ -1573,7 +1583,7 @@ struct inode_operations {
                           loff_t len);
         int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
                       u64 len);
-};
+} ____cacheline_aligned;
 
 struct seq_file;
 
@@ -2158,8 +2168,8 @@ extern sector_t bmap(struct inode *, sector_t);
 #endif
 extern int notify_change(struct dentry *, struct iattr *);
 extern int inode_permission(struct inode *, int);
-extern int generic_permission(struct inode *, int,
-                int (*check_acl)(struct inode *, int));
+extern int generic_permission(struct inode *, int, unsigned int,
+                int (*check_acl)(struct inode *, int, unsigned int));
 
 static inline bool execute_ok(struct inode *inode)
 {
@@ -2230,6 +2240,7 @@ extern void iget_failed(struct inode *);
 extern void end_writeback(struct inode *);
 extern void __destroy_inode(struct inode *);
 extern struct inode *new_inode(struct super_block *);
+extern void free_inode_nonrcu(struct inode *inode);
 extern int should_remove_suid(struct dentry *);
 extern int file_remove_suid(struct file *);
 
@@ -2446,6 +2457,10 @@ static inline ino_t parent_ino(struct dentry *dentry)
 {
         ino_t res;
 
+        /*
+         * Don't strictly need d_lock here? If the parent ino could change
+         * then surely we'd have a deeper race in the caller?
+         */
         spin_lock(&dentry->d_lock);
         res = dentry->d_parent->d_inode->i_ino;
         spin_unlock(&dentry->d_lock);
diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h
index a42b5bf02f8b..003dc0fd7347 100644
--- a/include/linux/fs_struct.h
+++ b/include/linux/fs_struct.h
@@ -2,10 +2,13 @@
 #define _LINUX_FS_STRUCT_H
 
 #include <linux/path.h>
+#include <linux/spinlock.h>
+#include <linux/seqlock.h>
 
 struct fs_struct {
         int users;
         spinlock_t lock;
+        seqcount_t seq;
         int umask;
         int in_exec;
         struct path root, pwd;
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index b10bcdeaef76..2a53f10712b3 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -17,7 +17,6 @@
 
 /*
  * fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
  */
 static inline void fsnotify_d_instantiate(struct dentry *dentry,
                                           struct inode *inode)
@@ -62,7 +61,6 @@ static inline int fsnotify_perm(struct file *file, int mask)
 
 /*
  * fsnotify_d_move - dentry has been moved
- * Called with dcache_lock and dentry->d_lock held.
  */
 static inline void fsnotify_d_move(struct dentry *dentry)
 {
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 7380763595d3..69ad89b50489 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -329,9 +329,15 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 {
         struct dentry *parent;
 
-        assert_spin_locked(&dcache_lock);
         assert_spin_locked(&dentry->d_lock);
 
+        /*
+         * Serialisation of setting PARENT_WATCHED on the dentries is provided
+         * by d_lock. If inotify_inode_watched changes after we have taken
+         * d_lock, the following __fsnotify_update_child_dentry_flags call will
+         * find our entry, so it will spin until we complete here, and update
+         * us with the new state.
+         */
         parent = dentry->d_parent;
         if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode))
                 dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
@@ -341,15 +347,12 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 
 /*
  * fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
  */
 static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
 {
         if (!inode)
                 return;
 
-        assert_spin_locked(&dcache_lock);
-
         spin_lock(&dentry->d_lock);
         __fsnotify_update_dcache_flags(dentry);
         spin_unlock(&dentry->d_lock);
diff --git a/include/linux/generic_acl.h b/include/linux/generic_acl.h
index 574bea4013b6..0437e377b555 100644
--- a/include/linux/generic_acl.h
+++ b/include/linux/generic_acl.h
@@ -10,6 +10,6 @@ extern const struct xattr_handler generic_acl_default_handler;
 
 int generic_acl_init(struct inode *, struct inode *);
 int generic_acl_chmod(struct inode *);
-int generic_check_acl(struct inode *inode, int mask);
+int generic_check_acl(struct inode *inode, int mask, unsigned int flags);
 
 #endif /* LINUX_GENERIC_ACL_H */
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
new file mode 100644
index 000000000000..9ee97e7f2be4
--- /dev/null
+++ b/include/linux/list_bl.h
@@ -0,0 +1,144 @@
+#ifndef _LINUX_LIST_BL_H
+#define _LINUX_LIST_BL_H
+
+#include <linux/list.h>
+
+/*
+ * Special version of lists, where head of the list has a lock in the lowest
+ * bit. This is useful for scalable hash tables without increasing memory
+ * footprint overhead.
+ *
+ * For modification operations, the 0 bit of hlist_bl_head->first
+ * pointer must be set.
+ *
+ * With some small modifications, this can easily be adapted to store several
+ * arbitrary bits (not just a single lock bit), if the need arises to store
+ * some fast and compact auxiliary data.
+ */
+
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+#define LIST_BL_LOCKMASK        1UL
+#else
+#define LIST_BL_LOCKMASK        0UL
+#endif
+
+#ifdef CONFIG_DEBUG_LIST
+#define LIST_BL_BUG_ON(x) BUG_ON(x)
+#else
+#define LIST_BL_BUG_ON(x)
+#endif
+
+
+struct hlist_bl_head {
+        struct hlist_bl_node *first;
+};
+
+struct hlist_bl_node {
+        struct hlist_bl_node *next, **pprev;
+};
+#define INIT_HLIST_BL_HEAD(ptr) \
+        ((ptr)->first = NULL)
+
+static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h)
+{
+        h->next = NULL;
+        h->pprev = NULL;
+}
+
+#define hlist_bl_entry(ptr, type, member) container_of(ptr,type,member)
+
+static inline int hlist_bl_unhashed(const struct hlist_bl_node *h)
+{
+        return !h->pprev;
+}
+
+static inline struct hlist_bl_node *hlist_bl_first(struct hlist_bl_head *h)
+{
+        return (struct hlist_bl_node *)
+                ((unsigned long)h->first & ~LIST_BL_LOCKMASK);
+}
+
+static inline void hlist_bl_set_first(struct hlist_bl_head *h,
+                                        struct hlist_bl_node *n)
+{
+        LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
+        LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK));
+        h->first = (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK);
+}
+
+static inline int hlist_bl_empty(const struct hlist_bl_head *h)
+{
+        return !((unsigned long)h->first & ~LIST_BL_LOCKMASK);
+}
+
+static inline void hlist_bl_add_head(struct hlist_bl_node *n,
+                                        struct hlist_bl_head *h)
+{
+        struct hlist_bl_node *first = hlist_bl_first(h);
+
+        n->next = first;
+        if (first)
+                first->pprev = &n->next;
+        n->pprev = &h->first;
+        hlist_bl_set_first(h, n);
+}
+
+static inline void __hlist_bl_del(struct hlist_bl_node *n)
+{
+        struct hlist_bl_node *next = n->next;
+        struct hlist_bl_node **pprev = n->pprev;
+
+        LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
+
+        /* pprev may be `first`, so be careful not to lose the lock bit */
+        *pprev = (struct hlist_bl_node *)
+                        ((unsigned long)next |
+                         ((unsigned long)*pprev & LIST_BL_LOCKMASK));
+        if (next)
+                next->pprev = pprev;
+}
+
+static inline void hlist_bl_del(struct hlist_bl_node *n)
+{
+        __hlist_bl_del(n);
+        n->next = LIST_POISON1;
+        n->pprev = LIST_POISON2;
+}
+
+static inline void hlist_bl_del_init(struct hlist_bl_node *n)
+{
+        if (!hlist_bl_unhashed(n)) {
+                __hlist_bl_del(n);
+                INIT_HLIST_BL_NODE(n);
+        }
+}
+
+/**
+ * hlist_bl_for_each_entry      - iterate over list of given type
+ * @tpos:       the type * to use as a loop cursor.
+ * @pos:        the &struct hlist_node to use as a loop cursor.
+ * @head:       the head for your list.
+ * @member:     the name of the hlist_node within the struct.
+ *
+ */
+#define hlist_bl_for_each_entry(tpos, pos, head, member)                \
+        for (pos = hlist_bl_first(head);                                \
+             pos &&                                                     \
+                ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \
+             pos = pos->next)
+
+/**
+ * hlist_bl_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @tpos:       the type * to use as a loop cursor.
+ * @pos:        the &struct hlist_node to use as a loop cursor.
+ * @n:          another &struct hlist_node to use as temporary storage
+ * @head:       the head for your list.
+ * @member:     the name of the hlist_node within the struct.
+ */
+#define hlist_bl_for_each_entry_safe(tpos, pos, n, head, member)         \
+        for (pos = hlist_bl_first(head);                                 \
+             pos && ({ n = pos->next; 1; }) &&                           \
+                ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \
+             pos = n)
+
+#endif
diff --git a/include/linux/mount.h b/include/linux/mount.h
index 5e7a59408dd4..1869ea24a739 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -13,6 +13,7 @@
 #include <linux/list.h>
 #include <linux/nodemask.h>
 #include <linux/spinlock.h>
+#include <linux/seqlock.h>
 #include <asm/atomic.h>
 
 struct super_block;
@@ -46,12 +47,24 @@ struct mnt_namespace;
 
 #define MNT_INTERNAL    0x4000
 
+struct mnt_pcp {
+        int mnt_count;
+        int mnt_writers;
+};
+
 struct vfsmount {
         struct list_head mnt_hash;
         struct vfsmount *mnt_parent;    /* fs we are mounted on */
         struct dentry *mnt_mountpoint;  /* dentry of mountpoint */
         struct dentry *mnt_root;        /* root of the mounted tree */
         struct super_block *mnt_sb;     /* pointer to superblock */
+#ifdef CONFIG_SMP
+        struct mnt_pcp __percpu *mnt_pcp;
+        atomic_t mnt_longrefs;
+#else
+        int mnt_count;
+        int mnt_writers;
+#endif
         struct list_head mnt_mounts;    /* list of children, anchored here */
         struct list_head mnt_child;     /* and going through their mnt_child */
         int mnt_flags;
@@ -70,57 +83,25 @@ struct vfsmount {
         struct mnt_namespace *mnt_ns;   /* containing namespace */
         int mnt_id;                     /* mount identifier */
         int mnt_group_id;               /* peer group identifier */
-        /*
-         * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
-         * to let these frequently modified fields in a separate cache line
-         * (so that reads of mnt_flags wont ping-pong on SMP machines)
-         */
-        atomic_t mnt_count;
         int mnt_expiry_mark;            /* true if marked for expiry */
         int mnt_pinned;
         int mnt_ghosts;
-#ifdef CONFIG_SMP
-        int __percpu *mnt_writers;
-#else
-        int mnt_writers;
-#endif
 };
 
-static inline int *get_mnt_writers_ptr(struct vfsmount *mnt)
-{
-#ifdef CONFIG_SMP
-        return mnt->mnt_writers;
-#else
-        return &mnt->mnt_writers;
-#endif
-}
-
-static inline struct vfsmount *mntget(struct vfsmount *mnt)
-{
-        if (mnt)
-                atomic_inc(&mnt->mnt_count);
-        return mnt;
-}
-
 struct file; /* forward dec */
 
 extern int mnt_want_write(struct vfsmount *mnt);
 extern int mnt_want_write_file(struct file *file);
 extern int mnt_clone_write(struct vfsmount *mnt);
 extern void mnt_drop_write(struct vfsmount *mnt);
-extern void mntput_no_expire(struct vfsmount *mnt);
+extern void mntput(struct vfsmount *mnt);
+extern struct vfsmount *mntget(struct vfsmount *mnt);
+extern void mntput_long(struct vfsmount *mnt);
+extern struct vfsmount *mntget_long(struct vfsmount *mnt);
 extern void mnt_pin(struct vfsmount *mnt);
 extern void mnt_unpin(struct vfsmount *mnt);
 extern int __mnt_is_readonly(struct vfsmount *mnt);
 
-static inline void mntput(struct vfsmount *mnt)
-{
-        if (mnt) {
-                mnt->mnt_expiry_mark = 0;
-                mntput_no_expire(mnt);
-        }
-}
-
 extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
                                       const char *name, void *data);
 
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 05b441d93642..18d06add0a40 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -19,7 +19,10 @@ struct nameidata {
         struct path     path;
         struct qstr     last;
         struct path     root;
+        struct file     *file;
+        struct inode    *inode; /* path.dentry.d_inode */
         unsigned int    flags;
+        unsigned        seq;
         int             last_type;
         unsigned        depth;
         char *saved_names[MAX_NESTED_LINKS + 1];
@@ -41,14 +44,15 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  *  - require a directory
  *  - ending slashes ok even for nonexistent files
  *  - internal "there are more path components" flag
- *  - locked when lookup done with dcache_lock held
  *  - dentry cache is untrusted; force a real lookup
  */
-#define LOOKUP_FOLLOW            1
-#define LOOKUP_DIRECTORY         2
-#define LOOKUP_CONTINUE          4
-#define LOOKUP_PARENT           16
-#define LOOKUP_REVAL            64
+#define LOOKUP_FOLLOW           0x0001
+#define LOOKUP_DIRECTORY        0x0002
+#define LOOKUP_CONTINUE         0x0004
+
+#define LOOKUP_PARENT           0x0010
+#define LOOKUP_REVAL            0x0020
+#define LOOKUP_RCU              0x0040
 /*
  * Intent data
  */
diff --git a/include/linux/ncp_fs.h b/include/linux/ncp_fs.h
index ef663061d5ac..1c27f201c856 100644
--- a/include/linux/ncp_fs.h
+++ b/include/linux/ncp_fs.h
@@ -184,13 +184,13 @@ struct ncp_entry_info {
         __u8                    file_handle[6];
 };
 
-static inline struct ncp_server *NCP_SBP(struct super_block *sb)
+static inline struct ncp_server *NCP_SBP(const struct super_block *sb)
 {
         return sb->s_fs_info;
 }
 
 #define NCP_SERVER(inode)       NCP_SBP((inode)->i_sb)
-static inline struct ncp_inode_info *NCP_FINFO(struct inode *inode)
+static inline struct ncp_inode_info *NCP_FINFO(const struct inode *inode)
 {
         return container_of(inode, struct ncp_inode_info, vfs_inode);
 }
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 29d504d5d1c3..0779bb8f95be 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -351,7 +351,7 @@ extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
-extern int nfs_permission(struct inode *, int);
+extern int nfs_permission(struct inode *, int, unsigned int);
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);
 extern int nfs_attribute_timeout(struct inode *inode);
diff --git a/include/linux/path.h b/include/linux/path.h
index edc98dec6266..a581e8c06533 100644
--- a/include/linux/path.h
+++ b/include/linux/path.h
@@ -10,7 +10,9 @@ struct path {
 };
 
 extern void path_get(struct path *);
+extern void path_get_long(struct path *);
 extern void path_put(struct path *);
+extern void path_put_long(struct path *);
 
 static inline int path_equal(const struct path *path1, const struct path *path2)
 {
diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h
index 67608161df6b..d68283a898bb 100644
--- a/include/linux/posix_acl.h
+++ b/include/linux/posix_acl.h
@@ -108,6 +108,25 @@ static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
         return acl;
 }
 
+static inline int negative_cached_acl(struct inode *inode, int type)
+{
+        struct posix_acl **p, *acl;
+        switch (type) {
+        case ACL_TYPE_ACCESS:
+                p = &inode->i_acl;
+                break;
+        case ACL_TYPE_DEFAULT:
+                p = &inode->i_default_acl;
+                break;
+        default:
+                BUG();
+        }
+        acl = ACCESS_ONCE(*p);
+        if (acl)
+                return 0;
+        return 1;
+}
+
 static inline void set_cached_acl(struct inode *inode,
                                   int type,
                                   struct posix_acl *acl)
diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h
new file mode 100644
index 000000000000..b872b493724d
--- /dev/null
+++ b/include/linux/rculist_bl.h
@@ -0,0 +1,127 @@
+#ifndef _LINUX_RCULIST_BL_H
+#define _LINUX_RCULIST_BL_H
+
+/*
+ * RCU-protected bl list version. See include/linux/list_bl.h.
+ */
+#include <linux/list_bl.h>
+#include <linux/rcupdate.h>
+
+static inline void hlist_bl_set_first_rcu(struct hlist_bl_head *h,
+                                        struct hlist_bl_node *n)
+{
+        LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK);
+        LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK));
+        rcu_assign_pointer(h->first,
+                (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK));
+}
+
+static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head *h)
+{
+        return (struct hlist_bl_node *)
+                ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK);
+}
+
+/**
+ * hlist_bl_del_init_rcu - deletes entry from hash list with re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: hlist_bl_unhashed() on the node returns true after this. It is
+ * useful for RCU based read lockfree traversal if the writer side
+ * must know if the list entry is still hashed or already unhashed.
+ *
+ * In particular, it means that we can not poison the forward pointers
+ * that may still be used for walking the hash list and we can only
+ * zero the pprev pointer so list_unhashed() will return true after
+ * this.
+ *
+ * The caller must take whatever precautions are necessary (such as
+ * holding appropriate locks) to avoid racing with another
+ * list-mutation primitive, such as hlist_bl_add_head_rcu() or
+ * hlist_bl_del_rcu(), running on this same list.  However, it is
+ * perfectly legal to run concurrently with the _rcu list-traversal
+ * primitives, such as hlist_bl_for_each_entry_rcu().
+ */
+static inline void hlist_bl_del_init_rcu(struct hlist_bl_node *n)
+{
+        if (!hlist_bl_unhashed(n)) {
+                __hlist_bl_del(n);
+                n->pprev = NULL;
+        }
+}
+
+/**
+ * hlist_bl_del_rcu - deletes entry from hash list without re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: hlist_bl_unhashed() on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the hash list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_bl_add_head_rcu()
+ * or hlist_bl_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_bl_for_each_entry().
+ */
+static inline void hlist_bl_del_rcu(struct hlist_bl_node *n)
+{
+        __hlist_bl_del(n);
+        n->pprev = LIST_POISON2;
+}
+
+/**
+ * hlist_bl_add_head_rcu
+ * @n: the element to add to the hash list.
+ * @h: the list to add to.
+ *
+ * Description:
+ * Adds the specified element to the specified hlist_bl,
+ * while permitting racing traversals.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_bl_add_head_rcu()
+ * or hlist_bl_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_bl_for_each_entry_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs.  Regardless of the type of CPU, the
+ * list-traversal primitive must be guarded by rcu_read_lock().
+ */
+static inline void hlist_bl_add_head_rcu(struct hlist_bl_node *n,
+                                        struct hlist_bl_head *h)
+{
+        struct hlist_bl_node *first;
+
+        /* don't need hlist_bl_first_rcu because we're under lock */
+        first = hlist_bl_first(h);
+
+        n->next = first;
+        if (first)
+                first->pprev = &n->next;
+        n->pprev = &h->first;
+
+        /* need _rcu because we can have concurrent lock free readers */
+        hlist_bl_set_first_rcu(h, n);
+}
+/**
+ * hlist_bl_for_each_entry_rcu - iterate over rcu list of given type
+ * @tpos:       the type * to use as a loop cursor.
+ * @pos:        the &struct hlist_bl_node to use as a loop cursor.
+ * @head:       the head for your list.
+ * @member:     the name of the hlist_bl_node within the struct.
+ *
+ */
+#define hlist_bl_for_each_entry_rcu(tpos, pos, head, member)            \
+        for (pos = hlist_bl_first_rcu(head);                            \
+                pos &&                                                  \
+                ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1; }); \
+                pos = rcu_dereference_raw(pos->next))
+
+#endif
diff --git a/include/linux/reiserfs_xattr.h b/include/linux/reiserfs_xattr.h
index b2cf2089769b..3b94c91f20a6 100644
--- a/include/linux/reiserfs_xattr.h
+++ b/include/linux/reiserfs_xattr.h
@@ -41,7 +41,7 @@ int reiserfs_xattr_init(struct super_block *sb, int mount_flags);
 int reiserfs_lookup_privroot(struct super_block *sb);
 int reiserfs_delete_xattrs(struct inode *inode);
 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs);
-int reiserfs_permission(struct inode *inode, int mask);
+int reiserfs_permission(struct inode *inode, int mask, unsigned int flags);
 
 #ifdef CONFIG_REISERFS_FS_XATTR
 #define has_xattr_dir(inode) (REISERFS_I(inode)->i_flags & i_has_xattr_dir)
diff --git a/include/linux/security.h b/include/linux/security.h
index d47a4c24b3e4..1ac42475ea08 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -457,7 +457,6 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *      called when the actual read/write operations are performed.
  *      @inode contains the inode structure to check.
  *      @mask contains the permission mask.
- *      @nd contains the nameidata (may be NULL).
  *      Return 0 if permission is granted.
  * @inode_setattr:
  *      Check permission before setting file attributes.  Note that the kernel
@@ -1713,6 +1712,7 @@ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry,
 int security_inode_readlink(struct dentry *dentry);
 int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd);
 int security_inode_permission(struct inode *inode, int mask);
+int security_inode_exec_permission(struct inode *inode, unsigned int flags);
 int security_inode_setattr(struct dentry *dentry, struct iattr *attr);
 int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry);
 int security_inode_setxattr(struct dentry *dentry, const char *name,
@@ -2102,6 +2102,12 @@ static inline int security_inode_permission(struct inode *inode, int mask)
         return 0;
 }
 
+static inline int security_inode_exec_permission(struct inode *inode,
+                                                  unsigned int flags)
+{
+        return 0;
+}
+
 static inline int security_inode_setattr(struct dentry *dentry,
                                           struct iattr *attr)
 {
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 632205ccc25d..e98cd2e57194 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -107,7 +107,7 @@ static __always_inline int read_seqretry(const seqlock_t *sl, unsigned start)
 {
         smp_rmb();
 
-        return (sl->sequence != start);
+        return unlikely(sl->sequence != start);
 }
 
 
@@ -125,14 +125,25 @@ typedef struct seqcount {
 #define SEQCNT_ZERO { 0 }
 #define seqcount_init(x)        do { *(x) = (seqcount_t) SEQCNT_ZERO; } while (0)
 
-/* Start of read using pointer to a sequence counter only.  */
-static inline unsigned read_seqcount_begin(const seqcount_t *s)
+/**
+ * __read_seqcount_begin - begin a seq-read critical section (without barrier)
+ * @s: pointer to seqcount_t
+ * Returns: count to be passed to read_seqcount_retry
+ *
+ * __read_seqcount_begin is like read_seqcount_begin, but has no smp_rmb()
+ * barrier. Callers should ensure that smp_rmb() or equivalent ordering is
+ * provided before actually loading any of the variables that are to be
+ * protected in this critical section.
+ *
+ * Use carefully, only in critical code, and comment how the barrier is
+ * provided.
+ */
+static inline unsigned __read_seqcount_begin(const seqcount_t *s)
 {
         unsigned ret;
 
 repeat:
         ret = s->sequence;
-        smp_rmb();
         if (unlikely(ret & 1)) {
                 cpu_relax();
                 goto repeat;
@@ -140,14 +151,56 @@ repeat:
         return ret;
 }
 
-/*
- * Test if reader processed invalid data because sequence number has changed.
+/**
+ * read_seqcount_begin - begin a seq-read critical section
+ * @s: pointer to seqcount_t
+ * Returns: count to be passed to read_seqcount_retry
+ *
+ * read_seqcount_begin opens a read critical section of the given seqcount.
+ * Validity of the critical section is tested by checking read_seqcount_retry
+ * function.
+ */
+static inline unsigned read_seqcount_begin(const seqcount_t *s)
+{
+        unsigned ret = __read_seqcount_begin(s);
+        smp_rmb();
+        return ret;
+}
+
+/**
+ * __read_seqcount_retry - end a seq-read critical section (without barrier)
+ * @s: pointer to seqcount_t
+ * @start: count, from read_seqcount_begin
+ * Returns: 1 if retry is required, else 0
+ *
+ * __read_seqcount_retry is like read_seqcount_retry, but has no smp_rmb()
+ * barrier. Callers should ensure that smp_rmb() or equivalent ordering is
+ * provided before actually loading any of the variables that are to be
+ * protected in this critical section.
+ *
+ * Use carefully, only in critical code, and comment how the barrier is
+ * provided.
+ */
+static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start)
+{
+        return unlikely(s->sequence != start);
+}
+
+/**
+ * read_seqcount_retry - end a seq-read critical section
+ * @s: pointer to seqcount_t
+ * @start: count, from read_seqcount_begin
+ * Returns: 1 if retry is required, else 0
+ *
+ * read_seqcount_retry closes a read critical section of the given seqcount.
+ * If the critical section was invalid, it must be ignored (and typically
+ * retried).
  */
 static inline int read_seqcount_retry(const seqcount_t *s, unsigned start)
 {
         smp_rmb();
 
-        return s->sequence != start;
+        return __read_seqcount_retry(s, start);
 }
 
 
@@ -167,6 +220,19 @@ static inline void write_seqcount_end(seqcount_t *s)
         s->sequence++;
 }
 
+/**
+ * write_seqcount_barrier - invalidate in-progress read-side seq operations
+ * @s: pointer to seqcount_t
+ *
+ * After write_seqcount_barrier, no read-side seq operations will complete
+ * successfully and see data older than this.
+ */
+static inline void write_seqcount_barrier(seqcount_t *s)
+{
+        smp_wmb();
+        s->sequence+=2;
+}
+
 /*
  * Possible sw/hw IRQ protected versions of the interfaces.
  */
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 59260e21bdf5..fa9086647eb7 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -106,8 +106,6 @@ int kmem_cache_shrink(struct kmem_cache *);
 void kmem_cache_free(struct kmem_cache *, void *);
 unsigned int kmem_cache_size(struct kmem_cache *);
 const char *kmem_cache_name(struct kmem_cache *);
-int kern_ptr_validate(const void *ptr, unsigned long size);
-int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
 
 /*
  * Please use this macro to create slab caches. Simply specify the