linux-ext4 - [PATCH 06/12] libext2fs: further clean up and rename check_block

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1390197254-14583-7-git-send-email-tytso@mit.edu>
Date:	Mon, 20 Jan 2014 00:54:08 -0500
From:	Theodore Ts'o <tytso@....edu>
To:	Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc:	Theodore Ts'o <tytso@....edu>,
	"Darrick J. Wong" <darrick.wong@...cle.com>
Subject: [PATCH 06/12] libext2fs: further clean up and rename check_block_uninit

Commit 8e44eb64bb (libext2fs: mark group data blocks when loading
block bitmap) simplified check_block_uninit since we are now
initializing the bitmap when it is loaded from disk.  It left some
variables which were being set but never used, however.  In addition,
since we only need check_block_uninit() to clear the block bitmap's
uninit flag, rename it to clear_block_uninit(), and only call it once
we have found a free block in ext2fs_new_blocks2().

This cleans up the code some and optimizes things if we need to search
multiple block groups trying to find a free block.

Signed-off-by: "Theodore Ts'o" <tytso@....edu>
Cc: Darrick J. Wong <darrick.wong@...cle.com>
---
 lib/ext2fs/alloc.c | 33 +++++----------------------------
 1 file changed, 5 insertions(+), 28 deletions(-)

diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
index 42096a4..91637dd 100644
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -27,31 +27,15 @@
 #include "ext2fs.h"
 
 /*
- * Check for uninit block bitmaps and deal with them appropriately
+ * Clear the uninit block bitmap flag if necessary
  */
-static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map,
-			       dgrp_t group)
+static void clear_block_uninit(ext2_filsys fs, dgrp_t group)
 {
-	blk_t		i;
-	blk64_t		blk, super_blk, old_desc_blk, new_desc_blk;
-	int		old_desc_blocks;
-
 	if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
 	    !(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)))
 		return;
 
-	blk = ext2fs_group_first_block2(fs, group);
-
-	ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
-				  &old_desc_blk, &new_desc_blk, 0);
-
-	if (fs->super->s_feature_incompat &
-	    EXT2_FEATURE_INCOMPAT_META_BG)
-		old_desc_blocks = fs->super->s_first_meta_bg;
-	else
-		old_desc_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
-
 	/* uninit block bitmaps are now initialized in read_bitmaps() */
 
 	ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
@@ -78,10 +62,11 @@ static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
 		ext2fs_fast_unmark_inode_bitmap2(map, ino);
 
 	ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
+	/* Mimics what the kernel does */
+	ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
 	ext2fs_group_desc_csum_set(fs, group);
 	ext2fs_mark_ib_dirty(fs);
 	ext2fs_mark_super_dirty(fs);
-	check_block_uninit(fs, fs->block_map, group);
 }
 
 /*
@@ -167,17 +152,9 @@ errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
 	c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
 	if (c_ratio > 1)
 		goal &= ~EXT2FS_CLUSTER_MASK(fs);
-	check_block_uninit(fs, map,
-			   (i - fs->super->s_first_data_block) /
-			   EXT2_BLOCKS_PER_GROUP(fs->super));
 	do {
-		if (((i - fs->super->s_first_data_block) %
-		     EXT2_BLOCKS_PER_GROUP(fs->super)) == 0)
-			check_block_uninit(fs, map,
-					   (i - fs->super->s_first_data_block) /
-					   EXT2_BLOCKS_PER_GROUP(fs->super));
-
 		if (!ext2fs_fast_test_block_bitmap2(map, i)) {
+			clear_block_uninit(fs, ext2fs_group_of_blk2(fs, i));
 			*ret = i;
 			return 0;
 		}
-- 
1.8.5.rc3.362.gdf10213

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html