ext2fs: update allocation info earlier in ext2fs_mkdir() and ext2fs_symlink()

Currently, ext2fs_mkdir() and ext2fs_symlink() update allocation bitmaps
and other information only close to the end of the function, in
particular after calling to ext2fs_link(). When ext2fs_link() will
support indexed directories, it will also need to allocate blocks and
that would cause filesystem corruption in case allocation info isn't
properly updated. So make sure ext2fs_mkdir() and ext2fs_symlink()
update allocation info before calling into ext2fs_link().

[ Added error handling so the calls to ext2fs_{block,inode}_alloc_stats()
  can be undone if the newly created directory or symlink can not be linked
  into the directory. -- TYT ]

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/mkdir.c b/lib/ext2fs/mkdir.c
index 2a63aad..437c8ff 100644 (file)
--- a/lib/ext2fs/mkdir.c
+++ b/lib/ext2fs/mkdir.c
@@ -43,6 +43,7 @@ errcode_t ext2fs_mkdir(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t inum,
        blk64_t                 blk;
        char                    *block = 0;
        int                     inline_data = 0;
+       int                     drop_refcount = 0;
 
        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 
@@ -144,6 +145,14 @@ errcode_t ext2fs_mkdir(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t inum,
        }
 
        /*
+        * Update accounting....
+        */
+       if (!inline_data)
+               ext2fs_block_alloc_stats2(fs, blk, +1);
+       ext2fs_inode_alloc_stats2(fs, ino, +1, 1);
+       drop_refcount = 1;
+
+       /*
         * Link the directory into the filesystem hierarchy
         */
        if (name) {
@@ -174,17 +183,16 @@ errcode_t ext2fs_mkdir(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t inum,
                if (retval)
                        goto cleanup;
        }
-
-       /*
-        * Update accounting....
-        */
-       if (!inline_data)
-               ext2fs_block_alloc_stats2(fs, blk, +1);
-       ext2fs_inode_alloc_stats2(fs, ino, +1, 1);
+       drop_refcount = 0;
 
 cleanup:
        if (block)
                ext2fs_free_mem(&block);
+       if (drop_refcount) {
+               if (!inline_data)
+                       ext2fs_block_alloc_stats2(fs, blk, -1);
+               ext2fs_inode_alloc_stats2(fs, ino, -1, 1);
+       }
        return retval;
 
 }

diff --git a/lib/ext2fs/symlink.c b/lib/ext2fs/symlink.c
index 7f78c5f..a66fb7e 100644 (file)
--- a/lib/ext2fs/symlink.c
+++ b/lib/ext2fs/symlink.c
@@ -54,6 +54,7 @@ errcode_t ext2fs_symlink(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t ino,
        int                     fastlink, inlinelink;
        unsigned int            target_len;
        char                    *block_buf = 0;
+       int                     drop_refcount = 0;
 
        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 
@@ -163,6 +164,14 @@ need_block:
        }
 
        /*
+        * Update accounting....
+        */
+       if (!fastlink && !inlinelink)
+               ext2fs_block_alloc_stats2(fs, blk, +1);
+       ext2fs_inode_alloc_stats2(fs, ino, +1, 0);
+       drop_refcount = 1;
+
+       /*
         * Link the symlink into the filesystem hierarchy
         */
        if (name) {
@@ -178,17 +187,16 @@ need_block:
                if (retval)
                        goto cleanup;
        }
-
-       /*
-        * Update accounting....
-        */
-       if (!fastlink && !inlinelink)
-               ext2fs_block_alloc_stats2(fs, blk, +1);
-       ext2fs_inode_alloc_stats2(fs, ino, +1, 0);
+       drop_refcount = 0;
 
 cleanup:
        if (block_buf)
                ext2fs_free_mem(&block_buf);
+       if (drop_refcount) {
+               if (!fastlink && !inlinelink)
+                       ext2fs_block_alloc_stats2(fs, blk, -1);
+               ext2fs_inode_alloc_stats2(fs, ino, -1, 0);
+       }
        return retval;
 }