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

Commit 1c6bd7173d 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: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2012-09-19 00:55:56 -04:00
parent c9b92530a7
commit 59e31c156a

View file

@ -1772,23 +1772,18 @@ static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
handle_t *handle; handle_t *handle;
struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_super_block *es = sbi->s_es; 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; ext4_fsblk_t nr;
int i, ret, err = 0; int i, ret, err = 0;
int credits = 1; int credits = 1;
ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg"); 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) { if (es->s_reserved_gdt_blocks) {
ext4_error(sb, "Unexpected non-zero " ext4_error(sb, "Unexpected non-zero "
"s_reserved_gdt_blocks"); "s_reserved_gdt_blocks");
return -EPERM; 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 */ /* Do a quick sanity check of the resize inode */
if (inode->i_blocks != 1 << (inode->i_blkbits - 9)) if (inode->i_blocks != 1 << (inode->i_blkbits - 9))
@ -1873,12 +1868,19 @@ 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 err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
int meta_bg; 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: retry:
o_blocks_count = ext4_blocks_count(es); o_blocks_count = ext4_blocks_count(es);
if (test_opt(sb, DEBUG)) ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu "
ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu " "to %llu blocks", o_blocks_count, n_blocks_count);
"to %llu blocks", o_blocks_count, n_blocks_count);
if (n_blocks_count < o_blocks_count) { if (n_blocks_count < o_blocks_count) {
/* On-line shrinking not supported */ /* On-line shrinking not supported */
@ -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); err = ext4_convert_meta_bg(sb, resize_inode);
if (err) if (err)
goto out; 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 */ /* extend the last group */
if (n_group == o_group) if (n_group == o_group)
add = n_blocks_count - o_blocks_count; add = n_blocks_count - o_blocks_count;
@ -2005,8 +1999,6 @@ out:
free_flex_gd(flex_gd); free_flex_gd(flex_gd);
if (resize_inode != NULL) if (resize_inode != NULL)
iput(resize_inode); iput(resize_inode);
if (test_opt(sb, DEBUG)) ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count);
ext4_msg(sb, KERN_DEBUG, "resized filesystem to %llu",
n_blocks_count);
return err; return err;
} }