@@ -243,6 +243,7 @@ static int ext4_alloc_group_tables(struct super_block *sb,
ext4_group_t group;
ext4_group_t last_group;
unsigned overhead;
+ __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0;
BUG_ON(flex_gd->count == 0 || group_data == NULL);
@@ -266,7 +267,7 @@ next_group:
src_group++;
for (; src_group <= last_group; src_group++) {
overhead = ext4_group_overhead_blocks(sb, src_group);
- if (overhead != 0)
+ if (overhead == 0)
last_blk += group_data[src_group - group].blocks_count;
else
break;
@@ -280,8 +281,7 @@ next_group:
group = ext4_get_group_number(sb, start_blk - 1);
group -= group_data[0].group;
group_data[group].free_blocks_count--;
- if (flexbg_size > 1)
- flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
+ flex_gd->bg_flags[group] &= uninit_mask;
}
/* Allocate inode bitmaps */
@@ -292,22 +292,30 @@ next_group:
group = ext4_get_group_number(sb, start_blk - 1);
group -= group_data[0].group;
group_data[group].free_blocks_count--;
- if (flexbg_size > 1)
- flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
+ flex_gd->bg_flags[group] &= uninit_mask;
}
/* Allocate inode tables */
for (; it_index < flex_gd->count; it_index++) {
- if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk)
+ unsigned int itb = EXT4_SB(sb)->s_itb_per_group;
+ ext4_fsblk_t next_group_start;
+
+ if (start_blk + itb > last_blk)
goto next_group;
group_data[it_index].inode_table = start_blk;
- group = ext4_get_group_number(sb, start_blk - 1);
+ group = ext4_get_group_number(sb, start_blk);
+ next_group_start = ext4_group_first_block_no(sb, group + 1);
group -= group_data[0].group;
- group_data[group].free_blocks_count -=
- EXT4_SB(sb)->s_itb_per_group;
- if (flexbg_size > 1)
- flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
+ if (start_blk + itb > next_group_start) {
+ flex_gd->bg_flags[group + 1] &= uninit_mask;
+ overhead = start_blk + itb - next_group_start;
+ group_data[group + 1].free_blocks_count -= overhead;
+ itb -= overhead;
+ }
+
+ group_data[group].free_blocks_count -= itb;
+ flex_gd->bg_flags[group] &= uninit_mask;
start_blk += EXT4_SB(sb)->s_itb_per_group;
}
@@ -620,7 +628,7 @@ handle_ib:
if (err)
goto out;
count = group_table_count[j];
- start = group_data[i].block_bitmap;
+ start = (&group_data[i].block_bitmap)[j];
block = start;
}
This is a note to let you know that I have just added a patch titled ext4: fix online resize with very large inode tables to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From e73c0d732e08a1a794c936c91c4b1446b3abf82a Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso@mit.edu> Date: Sat, 15 Feb 2014 21:33:13 -0500 Subject: ext4: fix online resize with very large inode tables commit b93c95353413041a8cebad915a8109619f66bcc6 upstream. If a file system has a large number of inodes per block group, all of the metadata blocks in a flex_bg may be larger than what can fit in a single block group. Unfortunately, ext4_alloc_group_tables() in resize.c was never tested to see if it would handle this case correctly, and there were a large number of bugs which caused the following sequence to result in a BUG_ON: kernel bug at fs/ext4/resize.c:409! ... call trace: [<ffffffff81256768>] ext4_flex_group_add+0x1448/0x1830 [<ffffffff81257de2>] ext4_resize_fs+0x7b2/0xe80 [<ffffffff8123ac50>] ext4_ioctl+0xbf0/0xf00 [<ffffffff811c111d>] do_vfs_ioctl+0x2dd/0x4b0 [<ffffffff811b9df2>] ? final_putname+0x22/0x50 [<ffffffff811c1371>] sys_ioctl+0x81/0xa0 [<ffffffff81676aa9>] system_call_fastpath+0x16/0x1b code: c8 4c 89 df e8 41 96 f8 ff 44 89 e8 49 01 c4 44 29 6d d4 0 rip [<ffffffff81254fa1>] set_flexbg_block_bitmap+0x171/0x180 This can be reproduced with the following command sequence: mke2fs -t ext4 -i 4096 /dev/vdd 1G mount -t ext4 /dev/vdd /vdd resize2fs /dev/vdd 8G To fix this, we need to make sure the right thing happens when a block group's inode table straddles two block groups, which means the following bugs had to be fixed: 1) Not clearing the BLOCK_UNINIT flag in the second block group in ext4_alloc_group_tables --- the was proximate cause of the BUG_ON. 2) Incorrectly determining how many block groups contained contiguous free blocks in ext4_alloc_group_tables(). 3) Incorrectly setting the start of the next block range to be marked in use after a discontinuity in setup_new_flex_group_blocks(). Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/ext4/resize.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) -- 1.9.0