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]
Date:	Tue, 10 Dec 2013 17:23:40 -0800
From:	"Darrick J. Wong" <darrick.wong@...cle.com>
To:	tytso@....edu, darrick.wong@...cle.com
Cc:	linux-ext4@...r.kernel.org
Subject: [PATCH 48/74] resize2fs: don't free in-use clusters when moving blocks

When we're moving blocks around the filesystem, ensure that freeing
the old blocks only frees the clusters if they're not in use by other
metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@...cle.com>
---
 resize/resize2fs.c |   72 ++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 63 insertions(+), 9 deletions(-)


diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index 49fe986..6c2c870 100644
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -870,12 +870,12 @@ static errcode_t blocks_to_move(ext2_resize_t rfs)
 	int		j, has_super;
 	dgrp_t		i, max_groups, g;
 	blk64_t		blk, group_blk;
-	blk64_t		old_blocks, new_blocks;
+	blk64_t		old_blocks, new_blocks, group_end, cluster_freed;
 	blk64_t		new_size;
 	unsigned int	meta_bg, meta_bg_size;
 	errcode_t	retval;
 	ext2_filsys 	fs, old_fs;
-	ext2fs_block_bitmap	meta_bmap;
+	ext2fs_block_bitmap	meta_bmap, new_meta_bmap = NULL;
 	int		flex_bg;
 
 	fs = rfs->new_fs;
@@ -982,15 +982,42 @@ static errcode_t blocks_to_move(ext2_resize_t rfs)
 	 * blocks as free.
 	 */
 	if (old_blocks > new_blocks) {
+		if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
+			retval = ext2fs_allocate_block_bitmap(fs,
+							_("new meta blocks"),
+							&new_meta_bmap);
+			if (retval)
+				goto errout;
+
+			retval = mark_table_blocks(fs, new_meta_bmap);
+			if (retval)
+				goto errout;
+		}
+
 		for (i = 0; i < max_groups; i++) {
 			if (!ext2fs_bg_has_super(fs, i)) {
 				group_blk += fs->super->s_blocks_per_group;
 				continue;
 			}
-			for (blk = group_blk+1+new_blocks;
-			     blk < group_blk+1+old_blocks; blk++) {
-				ext2fs_block_alloc_stats2(fs, blk, -1);
+			group_end = group_blk + 1 + old_blocks;
+			for (blk = group_blk + 1 + new_blocks;
+			     blk < group_end;) {
+				if (new_meta_bmap == NULL ||
+				    !ext2fs_test_block_bitmap2(new_meta_bmap,
+							       blk)) {
+					cluster_freed =
+						EXT2FS_CLUSTER_RATIO(fs) -
+						(blk &
+						 EXT2FS_CLUSTER_MASK(fs));
+					if (cluster_freed > group_end - blk)
+						cluster_freed = group_end - blk;
+					ext2fs_block_alloc_stats2(fs, blk, -1);
+					blk += EXT2FS_CLUSTER_RATIO(fs);
+					rfs->needed_blocks -= cluster_freed;
+					continue;
+				}
 				rfs->needed_blocks--;
+				blk++;
 			}
 			group_blk += fs->super->s_blocks_per_group;
 		}
@@ -1136,6 +1163,8 @@ static errcode_t blocks_to_move(ext2_resize_t rfs)
 	retval = 0;
 
 errout:
+	if (new_meta_bmap)
+		ext2fs_free_block_bitmap(new_meta_bmap);
 	if (meta_bmap)
 		ext2fs_free_block_bitmap(meta_bmap);
 
@@ -1809,9 +1838,10 @@ static errcode_t move_itables(ext2_resize_t rfs)
 	dgrp_t		i, max_groups;
 	ext2_filsys	fs = rfs->new_fs;
 	char		*cp;
-	blk64_t		old_blk, new_blk, blk;
+	blk64_t		old_blk, new_blk, blk, cluster_freed;
 	errcode_t	retval;
 	int		j, to_move, moved;
+	ext2fs_block_bitmap	new_bmap = NULL;
 
 	max_groups = fs->group_desc_count;
 	if (max_groups > rfs->old_fs->group_desc_count)
@@ -1824,6 +1854,17 @@ static errcode_t move_itables(ext2_resize_t rfs)
 			return retval;
 	}
 
+	if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
+		retval = ext2fs_allocate_block_bitmap(fs, _("new meta blocks"),
+						      &new_bmap);
+		if (retval)
+			return retval;
+
+		retval = mark_table_blocks(fs, new_bmap);
+		if (retval)
+			goto errout;
+	}
+
 	/*
 	 * Figure out how many inode tables we need to move
 	 */
@@ -1901,8 +1942,19 @@ static errcode_t move_itables(ext2_resize_t rfs)
 		}
 
 		for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
-		     j < fs->inode_blocks_per_group ; j++, blk++)
-			ext2fs_block_alloc_stats2(fs, blk, -1);
+		     j < fs->inode_blocks_per_group;) {
+			if (new_bmap == NULL ||
+			    !ext2fs_test_block_bitmap2(new_bmap, blk)) {
+				ext2fs_block_alloc_stats2(fs, blk, -1);
+				cluster_freed = EXT2FS_CLUSTER_RATIO(fs) -
+						(blk & EXT2FS_CLUSTER_MASK(fs));
+				blk += cluster_freed;
+				j += cluster_freed;
+				continue;
+			}
+			blk++;
+			j++;
+		}
 
 		ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
 		ext2fs_group_desc_csum_set(rfs->old_fs, i);
@@ -1922,9 +1974,11 @@ static errcode_t move_itables(ext2_resize_t rfs)
 	if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
 		printf("Inode table move finished.\n");
 #endif
-	return 0;
+	retval = 0;
 
 errout:
+	if (new_bmap)
+		ext2fs_free_block_bitmap(new_bmap);
 	return retval;
 }
 

--
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

Powered by blists - more mailing lists