Changeset 266 for trunk/kernel/vfs/vfs.c

Timestamp:

Jul 21, 2017, 1:51:24 PM (7 years ago)

Author:

alain

Message:

Implement vfs_lseek() function.

File:

• trunk/kernel/vfs/vfs.c (modified) (1 diff)

trunk/kernel/vfs/vfs.c

@@ -718 +718 @@
                    uint32_t * new_offset )
 {
-    printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
-    hal_core_sleep();
-    return 0;
-
-    assert( ( file_xp != XPTR_NULL ) , __FUNCTION__ , "file_xp == XPTR_NULL" );
+    xptr_t         offset_xp;
+    xptr_t         lock_xp;
+    cxy_t          file_cxy;
+    vfs_file_t  *  file_ptr;
+    vfs_inode_t *  inode_ptr;
+    uint32_t       new;
+
+    assert( (file_xp != XPTR_NULL) , __FUNCTION__ , "file_xp == XPTR_NULL" );
+
+    // get cluster and local pointer on remote file descriptor
+    file_cxy = GET_CXY( file_xp );
+    file_ptr = (vfs_file_t *)GET_PTR( file_xp );
+
+    // build extended pointers on lock and offset
+    offset_xp = XPTR( file_cxy , &file_ptr->offset );
+    lock_xp   = XPTR( file_cxy , &file_ptr->lock );
+
+    // take file descriptor lock
+    remote_rwlock_wr_lock( lock_xp );
+
+    if      ( whence == SEEK_CUR )   // new = current + offset
+    {
+        new = hal_remote_lw( offset_xp ) + offset;
+    }
+    else if ( whence == SEEK_SET )   // new = offset
+    {
+        new = offset;
+    }
+    else if ( whence == SEEK_END )   // new = size + offset
+    { 
+        // get local pointer on remote inode
+        inode_ptr = (vfs_inode_t *)hal_remote_lpt( XPTR( file_cxy , &file_ptr->inode ) );
+
+        new = hal_remote_lw( XPTR( file_cxy , &inode_ptr->size ) ) + offset;
+    }
+    else
+    {
+        printk("\n[ERROR] in %s : illegal whence value\n", __FUNCTION__ );
+        remote_rwlock_wr_unlock( lock_xp );
+        return -1;
+    }
+
+    // set new offset
+    hal_remote_sw( offset_xp , new );
+
+    // release file descriptor lock
+    remote_rwlock_wr_unlock( lock_xp );
+
+    // success
+    *new_offset = new;
+    return 0;
 
 }  // vfs_lseek()