Commit 59e31c15 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: fix online resizing when the # of block groups is constant 



Commit 1c6bd717 introduced a regression where an online resize
operation which did not change the number of block groups would fail,
i.e:

	mke2fs -t /dev/vdc 60000
	mount /dev/vdc
	resize2fs /dev/vdc 60001

This was due to a bug in the logic regarding when to try converting
the filesystem to use meta_bg.

Also fix up a number of other minor issues with the online resizing
code: (a) Fix a sparse warning; (b) only check to make sure the device
is large enough once, instead of multiple times through the resize
loop.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent c9b92530

fs/ext4/resize.c

+14 −22
Original line number Diff line number Diff line
@@ -1772,23 +1772,18 @@ static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) 
	handle_t *handle;

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct ext4_super_block *es = sbi->s_es;

	struct ext4_inode_info *ei = 0;

	struct ext4_inode_info *ei = EXT4_I(inode);

	ext4_fsblk_t nr;

	int i, ret, err = 0;

	int credits = 1;



	ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg");

	if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE)) {

	if (inode) {

		if (es->s_reserved_gdt_blocks) {

			ext4_error(sb, "Unexpected non-zero "

				   "s_reserved_gdt_blocks");

			return -EPERM;

		}

		if (!inode) {

			ext4_error(sb, "Unexpected NULL resize_inode");

			return -EPERM;

		}

		ei = EXT4_I(inode);



		/* Do a quick sanity check of the resize inode */

		if (inode->i_blocks != 1 << (inode->i_blkbits - 9))
@@ -1873,11 +1868,18 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 
	int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;

	int meta_bg;



	/* See if the device is actually as big as what was requested */

	bh = sb_bread(sb, n_blocks_count - 1);

	if (!bh) {

		ext4_warning(sb, "can't read last block, resize aborted");

		return -ENOSPC;

	}

	brelse(bh);



retry:

	o_blocks_count = ext4_blocks_count(es);



	if (test_opt(sb, DEBUG))

		ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu "

	ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "

		 "to %llu blocks", o_blocks_count, n_blocks_count);



	if (n_blocks_count < o_blocks_count) {
@@ -1922,7 +1924,7 @@ retry: 
		}

	}



	if ((!resize_inode && !meta_bg) || n_group == o_group) {

	if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) {

		err = ext4_convert_meta_bg(sb, resize_inode);

		if (err)

			goto out;
@@ -1937,14 +1939,6 @@ retry: 
		}

	}



	/* See if the device is actually as big as what was requested */

	bh = sb_bread(sb, n_blocks_count - 1);

	if (!bh) {

		ext4_warning(sb, "can't read last block, resize aborted");

		return -ENOSPC;

	}

	brelse(bh);



	/* extend the last group */

	if (n_group == o_group)

		add = n_blocks_count - o_blocks_count;
@@ -2005,8 +1999,6 @@ out: 
		free_flex_gd(flex_gd);

	if (resize_inode != NULL)

		iput(resize_inode);

	if (test_opt(sb, DEBUG))

		ext4_msg(sb, KERN_DEBUG, "resized filesystem to %llu",

			 n_blocks_count);

	ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count);

	return err;

}

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