From a0ade1deb86d2325aecc36272bb4505a6eec9235 Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Mon, 20 Feb 2012 23:02:06 -0500 Subject: ext4: fix resize when resizing within single group When resizing file system in the way that the new size of the file system is still in the same group (no new groups are added), then we can hit a BUG_ON in ext4_alloc_group_tables() BUG_ON(flex_gd->count == 0 || group_data == NULL); because flex_gd->count is zero. The reason is the missing check for such case, so the code always extend the last group fully and then attempt to add more groups, but at that time n_blocks_count is actually smaller than o_blocks_count. It can be easily reproduced like this: mkfs.ext4 -b 4096 /dev/sda 30M mount /dev/sda /mnt/test resize2fs /dev/sda 50M Fix this by checking whether the resize happens within the singe group and only add that many blocks into the last group to satisfy user request. Then o_blocks_count == n_blocks_count and the resize will exit successfully without and attempt to add more groups into the fs. Also fix mixing together block number and blocks count which might be confusing and can easily lead to off-by-one errors (but it is actually not the case here since the two occurrence of this mix-up will cancel each other). Signed-off-by: Lukas Czerner Reported-by: Milan Broz Reviewed-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" --- fs/ext4/resize.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index f9d948f0eb86..3fed79da0d2c 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1582,7 +1582,7 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) ext4_fsblk_t o_blocks_count; ext4_group_t o_group; ext4_group_t n_group; - ext4_grpblk_t offset; + ext4_grpblk_t offset, add; unsigned long n_desc_blocks; unsigned long o_desc_blocks; unsigned long desc_blocks; @@ -1605,7 +1605,7 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) return 0; ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset); - ext4_get_group_no_and_offset(sb, o_blocks_count, &o_group, &offset); + ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset); n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) / EXT4_DESC_PER_BLOCK(sb); @@ -1634,10 +1634,12 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) } brelse(bh); - if (offset != 0) { - /* extend the last group */ - ext4_grpblk_t add; - add = EXT4_BLOCKS_PER_GROUP(sb) - offset; + /* extend the last group */ + if (n_group == o_group) + add = n_blocks_count - o_blocks_count; + else + add = EXT4_BLOCKS_PER_GROUP(sb) - (offset + 1); + if (add > 0) { err = ext4_group_extend_no_check(sb, o_blocks_count, add); if (err) goto out; -- cgit v1.2.3 From 92b9781658dba287a1354ad74ed351f68c3ee740 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 19 Mar 2012 23:41:49 -0400 Subject: ext4: change some printk() calls to use ext4_msg() instead Signed-off-by: "Theodore Ts'o" --- fs/ext4/resize.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 3fed79da0d2c..b6ad461930ca 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1512,16 +1512,17 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, o_blocks_count = ext4_blocks_count(es); if (test_opt(sb, DEBUG)) - printk(KERN_DEBUG "EXT4-fs: extending last group from %llu to %llu blocks\n", - o_blocks_count, n_blocks_count); + ext4_msg(sb, KERN_DEBUG, + "extending last group from %llu to %llu blocks", + o_blocks_count, n_blocks_count); if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) return 0; if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { - printk(KERN_ERR "EXT4-fs: filesystem on %s:" - " too large to resize to %llu blocks safely\n", - sb->s_id, n_blocks_count); + ext4_msg(sb, KERN_ERR, + "filesystem too large to resize to %llu blocks safely", + n_blocks_count); if (sizeof(sector_t) < 8) ext4_warning(sb, "CONFIG_LBDAF not enabled"); return -EINVAL; @@ -1591,8 +1592,8 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) o_blocks_count = ext4_blocks_count(es); if (test_opt(sb, DEBUG)) - printk(KERN_DEBUG "EXT4-fs: resizing filesystem from %llu " - "upto %llu blocks\n", o_blocks_count, n_blocks_count); + ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu " + "to %llu blocks", o_blocks_count, n_blocks_count); if (n_blocks_count < o_blocks_count) { /* On-line shrinking not supported */ @@ -1676,7 +1677,7 @@ out: iput(resize_inode); if (test_opt(sb, DEBUG)) - printk(KERN_DEBUG "EXT4-fs: resized filesystem from %llu " - "upto %llu blocks\n", o_blocks_count, n_blocks_count); + ext4_msg(sb, KERN_DEBUG, "resized filesystem from %llu " + "upto %llu blocks", o_blocks_count, n_blocks_count); return err; } -- cgit v1.2.3 From 636d7e2e3b57543636d20cd083079300ccdd569d Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 20 Mar 2012 15:46:11 -0400 Subject: ext4: update s_free_{inodes,blocks}_count during online resize When we're doing an online resize of an ext4 filesystem, we need to update the free inode and block counts in the superblock so that fsck doesn't complain. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- fs/ext4/resize.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index b6ad461930ca..59fa0be27251 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1163,8 +1163,11 @@ static void ext4_update_super(struct super_block *sb, do_div(reserved_blocks, 100); ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); + ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * flex_gd->count); + le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) * + flex_gd->count); /* * We need to protect s_groups_count against other CPUs seeing @@ -1465,6 +1468,7 @@ static int ext4_group_extend_no_check(struct super_block *sb, } ext4_blocks_count_set(es, o_blocks_count + add); + ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, o_blocks_count + add); /* We add the blocks to the bitmap and set the group need init bit */ -- cgit v1.2.3