Fix kernel BUG at fs/ext4/mballoc.c:910! From: Valerie Clement <valerie.clement@xxxxxxxx> With the flex_bg feature enabled, a large file creation oopses the kernel. The BUG_ON is: BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb)); As the allocation of the bitmaps and the inode table can be done outside the block group with flex_bg, this allows to allocate up to EXT4_BLOCKS_PER_GROUP blocks in a group. Depending on the group size and the block size, extents might be larger than BLOCKS_PER_GROUP(); use EXT_INIT_MAX_LEN instead of BLOCKS_PER_GROUP(). This patch fixes the oops. Signed-off-by: Valerie Clement <valerie.clement@xxxxxxxx> --- fs/ext4/mballoc.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index b0f84b4..ccc33e9 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -34,6 +34,7 @@ #include <linux/pagemap.h> #include <linux/seq_file.h> #include <linux/version.h> +#include <linux/ext4_fs_extents.h> #include "group.h" /* @@ -907,7 +908,9 @@ static void ext4_mb_mark_free_simple(struct super_block *sb, unsigned short chunk; unsigned short border; - BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb)); + BUG_ON(len > EXT4_HAS_INCOMPAT_FEATURE(sb, + EXT4_FEATURE_INCOMPAT_FLEX_BG) ? EXT_INIT_MAX_LEN : + EXT4_BLOCKS_PER_GROUP(sb)); border = 2 << sb->s_blocksize_bits; - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
