# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1645036122 -3600
# Node ID a5430b30cd3a071b2e43c34cc680b0d3ebe6f729
# Parent  76be2dc3b29451b2a0c99f4b85558b5697883189
Consolidated reference count update functionality.

diff -r 76be2dc3b294 -r a5430b30cd3a libe2access/include/e2access/image.h
--- a/libe2access/include/e2access/image.h	Wed Feb 16 18:38:11 2022 +0100
+++ b/libe2access/include/e2access/image.h	Wed Feb 16 19:28:42 2022 +0100
@@ -61,7 +61,8 @@
 errcode_t image_inode(ext2_filsys fs, const char *pathname,
                       struct ext2_inode *inode);
 
-errcode_t image_inode_decrement(ext2_filsys fs, ext2_ino_t ino);
+errcode_t image_inode_refcount_update(ext2_filsys fs, ext2_ino_t ino,
+                                      int change);
 
 errcode_t image_list_dir(ext2_filsys fs, const char *path,
                          int (*proc)(struct ext2_dir_entry *, int, int, char *,
diff -r 76be2dc3b294 -r a5430b30cd3a libe2access/lib/src/image.c
--- a/libe2access/lib/src/image.c	Wed Feb 16 18:38:11 2022 +0100
+++ b/libe2access/lib/src/image.c	Wed Feb 16 19:28:42 2022 +0100
@@ -324,30 +324,26 @@
     return ext2fs_read_inode(fs, ino, inode);
 }
 
-/* Decrement the reference count on an inode. */
+/* Update the reference count for the given inode. */
 
-errcode_t image_inode_decrement(ext2_filsys fs, ext2_ino_t ino)
+errcode_t image_inode_refcount_update(ext2_filsys fs, ext2_ino_t ino, int change)
 {
-    struct ext2_inode_large inode;
-    errcode_t retval;
-
-    retval = ext2fs_read_inode_full(fs, ino,
-                                    (struct ext2_inode *) &inode,
-                                    sizeof(inode));
+    struct ext2_inode inode;
+    errcode_t retval = ext2fs_read_inode(fs, ino, &inode);
 
     if (retval)
         return retval;
 
     /* NOTE: FUSE implementation tests for > 1. */
 
-    if (inode.i_links_count)
-        inode.i_links_count--;
+    if ((change < 0) && (inode.i_links_count + change < 0))
+        inode.i_links_count = 0;
+    else
+        inode.i_links_count += change;
 
     /* NOTE: Update modification time. */
-
-    return ext2fs_write_inode_full(fs, ino,
-                                   (struct ext2_inode *) &inode,
-                                   sizeof(inode));
+    
+    return ext2fs_write_inode(fs, ino, &inode);
 }
 
 /* List a directory in the filesystem image. */
@@ -541,7 +537,7 @@
     /* Decrement the parent reference count for directories. */
 
     if (!retval && !inode.i_links_count && ino_parent)
-        retval = image_inode_decrement(fs, ino_parent);
+        retval = image_inode_refcount_update(fs, ino_parent, -1);
 
     return retval;
 }
@@ -561,7 +557,7 @@
                        ext2_ino_t target_parent, const char *target_basename)
 {
     errcode_t retval;
-    struct ext2_inode source_inode, source_parent_inode, target_parent_inode;
+    struct ext2_inode source_inode;
 
     /* NOTE: Should check for space. */
 
@@ -584,14 +580,7 @@
     {
         /* Update the link count for the target. */
 
-        retval = ext2fs_read_inode(fs, target_parent, &target_parent_inode);
-
-        if (retval)
-            return retval;
-
-        target_parent_inode.i_links_count++;
-
-        retval = ext2fs_write_inode(fs, target_parent, &target_parent_inode);
+        retval = image_inode_refcount_update(fs, target_parent, 1);
 
         if (retval)
             return retval;
@@ -604,14 +593,7 @@
 
         /* Update the link count for the source. */
 
-        retval = ext2fs_read_inode(fs, source_parent, &source_parent_inode);
-
-        if (retval)
-            return retval;
-
-        source_parent_inode.i_links_count--;
-
-        retval = ext2fs_write_inode(fs, source_parent, &source_parent_inode);
+        retval = image_inode_refcount_update(fs, source_parent, -1);
 
         if (retval)
             return retval;