1 ext4: only look at the bg_flags field if it is valid
3 The bg_flags field in the block group descripts is only valid if the
4 uninit_bg or metadata_csum feature is enabled. We were not
5 consistently looking at this field; fix this.
7 Also block group #0 must never have uninitialized allocation bitmaps,
8 or need to be zeroed, since that's where the root inode, and other
9 special inodes are set up. Check for these conditions and mark the
10 file system as corrupted if they are detected.
12 https://bugzilla.kernel.org/show_bug.cgi?id=199403
14 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
16 fs/ext4/balloc.c | 11 ++++++++++-
17 fs/ext4/ialloc.c | 14 ++++++++++++--
18 fs/ext4/mballoc.c | 6 ++++--
19 fs/ext4/super.c | 11 ++++++++++-
20 4 files changed, 36 insertions(+), 6 deletions(-)
22 diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
23 index 8a2e202ade8a..e68cefe08261 100644
24 --- a/fs/ext4/balloc.c
25 +++ b/fs/ext4/balloc.c
26 @@ -438,7 +438,16 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
29 ext4_lock_group(sb, block_group);
30 - if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
31 + if (ext4_has_group_desc_csum(sb) &&
32 + (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
33 + if (block_group == 0) {
34 + ext4_unlock_group(sb, block_group);
36 + ext4_error(sb, "Block bitmap for bg 0 marked "
38 + err = -EFSCORRUPTED;
41 err = ext4_init_block_bitmap(sb, bh, block_group, desc);
42 set_bitmap_uptodate(bh);
43 set_buffer_uptodate(bh);
44 diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
45 index 4d6e007f3569..da6c10c1e37a 100644
46 --- a/fs/ext4/ialloc.c
47 +++ b/fs/ext4/ialloc.c
48 @@ -150,7 +150,16 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
51 ext4_lock_group(sb, block_group);
52 - if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
53 + if (ext4_has_group_desc_csum(sb) &&
54 + (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
55 + if (block_group == 0) {
56 + ext4_unlock_group(sb, block_group);
58 + ext4_error(sb, "Inode bitmap for bg 0 marked "
60 + err = -EFSCORRUPTED;
63 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
64 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
65 sb->s_blocksize * 8, bh->b_data);
66 @@ -994,7 +1003,8 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
68 /* recheck and clear flag under lock if we still need to */
69 ext4_lock_group(sb, group);
70 - if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
71 + if (ext4_has_group_desc_csum(sb) &&
72 + (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
73 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
74 ext4_free_group_clusters_set(sb, gdp,
75 ext4_free_clusters_after_init(sb, group, gdp));
76 diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
77 index 243c42fdc155..402c769c51ea 100644
78 --- a/fs/ext4/mballoc.c
79 +++ b/fs/ext4/mballoc.c
80 @@ -2444,7 +2444,8 @@ int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
81 * initialize bb_free to be able to skip
82 * empty groups without initialization
84 - if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
85 + if (ext4_has_group_desc_csum(sb) &&
86 + (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
87 meta_group_info[i]->bb_free =
88 ext4_free_clusters_after_init(sb, group, desc);
90 @@ -3010,7 +3011,8 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
92 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
94 - if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
95 + if (ext4_has_group_desc_csum(sb) &&
96 + (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
97 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
98 ext4_free_group_clusters_set(sb, gdp,
99 ext4_free_clusters_after_init(sb,
100 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
101 index c61675d62195..4d34430d75f6 100644
102 --- a/fs/ext4/super.c
103 +++ b/fs/ext4/super.c
104 @@ -3139,13 +3139,22 @@ static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
105 ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
106 struct ext4_group_desc *gdp = NULL;
108 + if (!ext4_has_group_desc_csum(sb))
111 for (group = 0; group < ngroups; group++) {
112 gdp = ext4_get_group_desc(sb, group, NULL);
116 - if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
117 + if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
121 + ext4_error(sb, "Inode table for bg 0 marked as "
122 + "needing zeroing");