rewrite the device subsystem interfaces (#48)

[lunaix-os.git] / lunaix-os / kernel / fs / vfs.c

diff --git a/lunaix-os/kernel/fs/vfs.c b/lunaix-os/kernel/fs/vfs.c
index 415e36b6ec37056c192bc5af93c8b4a2e0436c26..0eec6bf517cb53eb7aeab3972b7915897c95da1b 100644 (file)
--- a/lunaix-os/kernel/fs/vfs.c
+++ b/lunaix-os/kernel/fs/vfs.c
@@ -270,12 +270,7 @@ vfs_pclose(struct v_file* file, pid_t pid)
 {
     struct v_inode* inode;
     int errno = 0;
-    
-    if (file->ref_count > 1) {
-        atomic_fetch_sub(&file->ref_count, 1);
-        return 0;
-    } 
-    
+
     inode = file->inode;
 
     /*
@@ -296,29 +291,42 @@ vfs_pclose(struct v_file* file, pid_t pid)
      * process is writing to this file later after B exit.
     */
 
-    if (mutex_on_hold(&inode->lock)) {
-        mutex_unlock_for(&inode->lock, pid);
+    mutex_unlock_for(&inode->lock, pid);
+    
+    if (file->ref_count > 1) {
+        atomic_fetch_sub(&file->ref_count, 1);
+        return 0;
     }
 
-    lock_inode(inode);
-
-    pcache_commit_all(inode);
     if ((errno = file->ops->close(file))) {
-        goto unlock;
+        goto done;
     }
 
     atomic_fetch_sub(&file->dnode->ref_count, 1);
+    mnt_chillax(file->dnode->mnt);
+    cake_release(file_pile, file);
+
+    /*
+        if the current inode is not being locked by other 
+        threads that does not share same open context,
+        then we can try to do sync opportunistically
+    */
+    if (mutex_on_hold(&inode->lock)) {
+        goto done;
+    }
+    
+    lock_inode(inode);
+
+    pcache_commit_all(inode);
     inode->open_count--;
 
     if (!inode->open_count) {
         __sync_inode_nolock(inode);
     }
 
-    mnt_chillax(file->dnode->mnt);
-    cake_release(file_pile, file);
-
-unlock:
     unlock_inode(inode);
+
+done:
     return errno;
 }
 
@@ -1652,20 +1660,20 @@ __DEFINE_LXSYSCALL2(int, fstat, int, fd, struct file_stat*, stat)
 
     if (check_device_node(vino)) {
         struct device* rdev = resolve_device(vino->data);
-        if (!rdev || rdev->magic != DEV_STRUCT_MAGIC) {
+        if (!rdev) {
             errno = EINVAL;
             goto done;
         }
 
         stat->st_rdev = (dev_t){.meta = rdev->ident.fn_grp,
                                 .unique = rdev->ident.unique,
-                                .index = rdev->dev_uid};
+                                .index = dev_uid(rdev) };
     }
 
     if (fdev) {
         stat->st_dev = (dev_t){.meta = fdev->ident.fn_grp,
                                .unique = fdev->ident.unique,
-                               .index = fdev->dev_uid};
+                               .index = dev_uid(fdev) };
     }
 
 done: