[PATCH] resize2fs: do not clear resize inode for 0 resvd blocks

[PATCH] resize2fs: do not clear resize inode for 0 resvd blocks

[Eric Sandeen]

I ran into odd behavior where mkfs.ext4 of a 16T filesystem would
create a resize inode with 0 reserved blocks, and mark the resize_inode
feature.

A subsequent slight downward resize of the filesystem would remove
the resize inode, making any further offline resizing impossible.

This is especially odd in light of the fact that a large downward
resize (say, to 8T) will actually add blocks to the resize inode -
so a small resize removes it, a large resize expands it ...

commit 8ade268cf2fde8629b51bfd1c044a83db88234cd had added this:

  If the filesystem is grown to the point where the resize_inode is no
  longer needed, clean it up properly so e2fsck doesn't have to.

but, it seems e2fsck does not care about this situation, either.

So, simply leave the resize_inode intact in this case, and everything
seems to be happy.

Note, this is for the 1.41.xx branch.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

Index: e2fsprogs/resize/resize2fs.c
===================================================================
--- e2fsprogs.orig/resize/resize2fs.c
+++ e2fsprogs/resize/resize2fs.c
@@ -1711,7 +1711,6 @@ static errcode_t fix_resize_inode(ext2_f
 	struct ext2_inode	inode;
 	errcode_t		retval;
 	char *			block_buf;
-	blk_t			blk;
 
 	if (!(fs->super->s_feature_compat &
 	      EXT2_FEATURE_COMPAT_RESIZE_INODE))
@@ -1723,20 +1722,6 @@ static errcode_t fix_resize_inode(ext2_f
 	retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
 	if (retval) goto errout;
 
-	if (fs->super->s_reserved_gdt_blocks == 0) {
-		fs->super->s_feature_compat &=
-			~EXT2_FEATURE_COMPAT_RESIZE_INODE;
-		ext2fs_mark_super_dirty(fs);
-
-		if ((blk = inode.i_block[EXT2_DIND_BLOCK]) != 0)
-			ext2fs_block_alloc_stats(fs, blk, -1);
-
-		memset(&inode, 0, sizeof(inode));
-
-		retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
-		goto errout;
-	}

Re: [PATCH] resize2fs: do not clear resize inode for 0 resvd blocks

[Ted Ts'o]

On Tue, Dec 21, 2010 at 03:32:05PM -0600, Eric Sandeen wrote:
> I ran into odd behavior where mkfs.ext4 of a 16T filesystem would
> create a resize inode with 0 reserved blocks, and mark the resize_inode
> feature.
> 
> A subsequent slight downward resize of the filesystem would remove
> the resize inode, making any further offline resizing impossible.
> 
> This is especially odd in light of the fact that a large downward
> resize (say, to 8T) will actually add blocks to the resize inode -
> so a small resize removes it, a large resize expands it ...
> 
> commit 8ade268cf2fde8629b51bfd1c044a83db88234cd had added this:
> 
>   If the filesystem is grown to the point where the resize_inode is no
>   longer needed, clean it up properly so e2fsck doesn't have to.
> 
> but, it seems e2fsck does not care about this situation, either.
> 
> So, simply leave the resize_inode intact in this case, and everything
> seems to be happy.
> 
> Note, this is for the 1.41.xx branch.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Thanks, applied.

						- Ted