3.18-stable review patch. If anyone has any objections, please let me know.
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From: Theodore Ts'o tytso@mit.edu
commit 819b23f1c501b17b9694325471789e6b5cc2d0d2 upstream.
Regardless of whether the flex_bg feature is set, we should always check to make sure the bits we are setting in the block bitmap are within the block group bounds.
https://bugzilla.kernel.org/show_bug.cgi?id=199865
Signed-off-by: Theodore Ts'o tytso@mit.edu [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk Signed-off-by: Greg Hackmann ghackmann@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/balloc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
--- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -184,7 +184,6 @@ static int ext4_init_block_bitmap(struct unsigned int bit, bit_max; struct ext4_sb_info *sbi = EXT4_SB(sb); ext4_fsblk_t start, tmp; - int flex_bg = 0; struct ext4_group_info *grp;
J_ASSERT_BH(bh, buffer_locked(bh)); @@ -217,22 +216,19 @@ static int ext4_init_block_bitmap(struct
start = ext4_group_first_block_no(sb, block_group);
- if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) - flex_bg = 1; - /* Set bits for block and inode bitmaps, and inode table */ tmp = ext4_block_bitmap(sb, gdp); - if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) + if (ext4_block_in_group(sb, tmp, block_group)) ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
tmp = ext4_inode_bitmap(sb, gdp); - if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) + if (ext4_block_in_group(sb, tmp, block_group)) ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
tmp = ext4_inode_table(sb, gdp); for (; tmp < ext4_inode_table(sb, gdp) + sbi->s_itb_per_group; tmp++) { - if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) + if (ext4_block_in_group(sb, tmp, block_group)) ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); }