1 files changed, 39 insertions, 24 deletions

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);