[ported from 2008.3] Add File Descriptor Attached Shared Objects (FDSO) infrastructure

3 files changed, 88 insertions, 12 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2620a8c63571..5c7e0ff370ba 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -15,8 +15,8 @@
  * nr_file rlimit, so it's safe to set up a ridiculously high absolute
  * upper limit on files-per-process.
  *
- * Some programs (notably those using select()) may have to be 
- * recompiled to take full advantage of the new limits..  
+ * Some programs (notably those using select()) may have to be
+ * recompiled to take full advantage of the new limits..
  */
 
 /* Fixed constants first: */
@@ -169,7 +169,7 @@ struct inodes_stat_t {
 #define SEL_EX          4
 
 /* public flags for file_system_type */
-#define FS_REQUIRES_DEV 1 
+#define FS_REQUIRES_DEV 1
 #define FS_BINARY_MOUNTDATA 2
 #define FS_HAS_SUBTYPE 4
 #define FS_REVAL_DOT    16384   /* Check the paths ".", ".." for staleness */
@@ -466,7 +466,7 @@ struct iattr {
  */
 #include <linux/quota.h>
 
-/** 
+/**
  * enum positive_aop_returns - aop return codes with specific semantics
  *
  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
@@ -476,7 +476,7 @@ struct iattr {
  *                          be a candidate for writeback again in the near
  *                          future.  Other callers must be careful to unlock
  *                          the page if they get this return.  Returned by
- *                          writepage(); 
+ *                          writepage();
  *
  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
  *                      unlocked it and the page might have been truncated.
@@ -715,6 +715,7 @@ static inline int mapping_writably_mapped(struct address_space *mapping)
 
 struct posix_acl;
 #define ACL_NOT_CACHED ((void *)(-1))
+struct inode_obj_id_table;
 
 struct inode {
         struct hlist_node       i_hash;
@@ -783,6 +784,8 @@ struct inode {
         struct posix_acl        *i_acl;
         struct posix_acl        *i_default_acl;
 #endif
+        struct list_head        i_obj_list;
+        struct mutex            i_obj_mutex;
         void                    *i_private; /* fs or device private pointer */
 };
 
@@ -995,10 +998,10 @@ static inline int file_check_writeable(struct file *filp)
 
 #define MAX_NON_LFS     ((1UL<<31) - 1)
 
-/* Page cache limit. The filesystems should put that into their s_maxbytes 
-   limits, otherwise bad things can happen in VM. */ 
+/* Page cache limit. The filesystems should put that into their s_maxbytes
+   limits, otherwise bad things can happen in VM. */
 #if BITS_PER_LONG==32
-#define MAX_LFS_FILESIZE        (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
+#define MAX_LFS_FILESIZE        (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
 #elif BITS_PER_LONG==64
 #define MAX_LFS_FILESIZE        0x7fffffffffffffffUL
 #endif
@@ -2139,7 +2142,7 @@ extern int may_open(struct path *, int, int);
 
 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
 extern struct file * open_exec(const char *);
- 
+
 /* fs/dcache.c -- generic fs support functions */
 extern int is_subdir(struct dentry *, struct dentry *);
 extern ino_t find_inode_number(struct dentry *, struct qstr *);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index bb046c0adf99..724814191fe9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1214,6 +1214,7 @@ struct sched_rt_entity {
 };
 
 struct rcu_node;
+struct od_table_entry;
 
 struct task_struct {
         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
@@ -1296,9 +1297,9 @@ struct task_struct {
         unsigned long stack_canary;
 #endif
 
-        /* 
+        /*
          * pointers to (original) parent process, youngest child, younger sibling,
-         * older sibling, respectively.  (p->father can be replaced with 
+         * older sibling, respectively.  (p->father can be replaced with
          * p->real_parent->pid)
          */
         struct task_struct *real_parent; /* real parent process */
@@ -1512,6 +1513,9 @@ struct task_struct {
         /* LITMUS RT parameters and state */
         struct rt_param rt_param;
 
+        /* references to PI semaphores, etc. */
+        struct od_table_entry *od_table;
+
 #ifdef CONFIG_LATENCYTOP
         int latency_record_count;
         struct latency_record latency_record[LT_SAVECOUNT];
@@ -2051,7 +2055,7 @@ static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, s
         spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 
         return ret;
-}       
+}
 
 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
                               sigset_t *mask);
diff --git a/include/litmus/fdso.h b/include/litmus/fdso.h
new file mode 100644
index 000000000000..286e10f86de0
--- /dev/null
+++ b/include/litmus/fdso.h
@@ -0,0 +1,69 @@
+/* fdso.h - file descriptor attached shared objects
+ *
+ * (c) 2007 B. Brandenburg, LITMUS^RT project
+ */
+
+#ifndef _LINUX_FDSO_H_
+#define _LINUX_FDSO_H_
+
+#include <linux/list.h>
+#include <asm/atomic.h>
+
+#include <linux/fs.h>
+
+#define MAX_OBJECT_DESCRIPTORS 32
+
+typedef enum  {
+        MIN_OBJ_TYPE    = 0,
+
+        FMLP_SEM        = 0,
+        SRP_SEM         = 1,
+
+        MAX_OBJ_TYPE    = 1
+} obj_type_t;
+
+struct inode_obj_id {
+        struct list_head        list;
+        atomic_t                count;
+        struct inode*           inode;
+
+        obj_type_t              type;
+        void*                   obj;
+        unsigned int            id;
+};
+
+
+struct od_table_entry {
+        unsigned int            used;
+
+        struct inode_obj_id*    obj;
+        void*                   extra;
+};
+
+struct fdso_ops {
+        void* (*create) (void);
+        void  (*destroy)(void*);
+        int   (*open)   (struct od_table_entry*, void* __user);
+        int   (*close)  (struct od_table_entry*);
+};
+
+/* translate a userspace supplied od into the raw table entry
+ * returns NULL if od is invalid
+ */
+struct od_table_entry* __od_lookup(int od);
+
+/* translate a userspace supplied od into the associated object
+ * returns NULL if od is invalid
+ */
+static inline void* od_lookup(int od, obj_type_t type)
+{
+        struct od_table_entry* e = __od_lookup(od);
+        return e && e->obj->type == type ? e->obj->obj : NULL;
+}
+
+#define lookup_fmlp_sem(od)((struct pi_semaphore*)  od_lookup(od, FMLP_SEM))
+#define lookup_srp_sem(od) ((struct srp_semaphore*) od_lookup(od, SRP_SEM))
+#define lookup_ics(od)     ((struct ics*)           od_lookup(od, ICS_ID))
+
+
+#endif