Changeset 445 for Whitix/branches/hybrid/fs

Timestamp:

05/06/08 22:26:59 (7 months ago)

Author:

mwhitworth

Message:

Add comments.

Files:

• Whitix/branches/hybrid/fs/vfs/dir.c (modified) (12 diffs)

Whitix/branches/hybrid/fs/vfs/dir.c

@@ -60 +60 @@
         }
         
+        /* Can't create a directory on a read-only filesystem. */
         if (dir->superBlock->flags & SB_RDONLY)
         {
@@ -66 +67 @@
         }
 
+        /* Check if the mkDir function actually exists. */
         if (!dir->vNodeOps || !dir->vNodeOps->mkDir)
         {
@@ -230 +232 @@
                 return err;
 
+        /* New root must be a directory */
         if (!(dirNode->mode & VFS_ATTR_DIR))
         {
@@ -236 +239 @@
         }
 
+        /* Change the current directory (and root) to the new root vNode,
+         * because we can't be sure the current directory doesn't point to a
+         * location outside that accessible by the root directory.
+         */
         VNodeRelease(current->cwd);
         VNodeRelease(current->root);
@@ -244 +251 @@
         return 0;
 }
+
+/***********************************************************************
+ *
+ * FUNCTION:    SysChangeRoot
+ *
+ * DESCRIPTION: Change the filesystem root for a particular process.
+ *
+ * PARAMETERS:  dirName - name of the directory that is the new root.
+ *
+ * RETURNS:             Usual error codes in error.h
+ *
+ ***********************************************************************/
 
 int SysChangeRoot(char* dirName)
@@ -288 +307 @@
 int FillDir(void* entries,char* name,int nameLen,DWORD vNum)
 {
-        struct FillDirInfo* curr=(struct FillDirInfo*)entries;
+        struct FillDirInfo* dirEntries=(struct FillDirInfo*)entries;
         int recordLen=ROUND_UP(offsetof(struct DirEntry,name)+nameLen+1);
 
@@ -294 +313 @@
                 return -EFAULT;
 
-        curr->curr->vNodeNum=vNum;
-        curr->curr->length=recordLen;
-        curr->curr->offset=0;
+        /* Fill in the current directory entry. */
+        dirEntries->curr->vNodeNum=vNum;
+        dirEntries->curr->length=recordLen;
+        dirEntries->curr->offset=0;
         memcpy(curr->curr->name,name,nameLen);
         curr->curr->name[nameLen]='\0';
+
+        /* And update the GetDirEntries state. */
         curr->count-=recordLen;
         curr->prev=curr->curr;
@@ -324 +346 @@
                 return -EBADF;
 
+        /* Must be able to write the directory entries to the given area of memory. */
         if (VirtCheckArea(entries,count,VER_WRITE))
                 return -EFAULT;
@@ -346 +369 @@
         }
 
+        /* Check if an error occured during ReadDir. If not, return the total byte-count of
+         * the ReadDir entries.
+         */
         if (fDirInfo.error)
                 return fDirInfo.error;
@@ -452 +478 @@
 
         /* Change to current for the duration of the lookup (Exec* needs it). */
-
         if (process != current)
         {
@@ -462 +487 @@
         }
 
+        /* Look up the directory vNode. */
         err=NameToVNode(&dirNode,dirName,FILE_READ | FILE_FORCE_OPEN);
         
+        /* And change back. */
         if (process != current)
         {
@@ -479 +506 @@
         }
 
+        /* Update the directory path string. Used in SysGetCurrDir. */
         AddStringPath(process,dirName);
 
+        /* And finally, update the current directory vNode for the process. */
         VNodeRelease(process->cwd);
         process->cwd=dirNode;