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authorKemeng Shi <shikemeng@huaweicloud.com>2023-03-04 01:21:01 +0800
committerTheodore Ts'o <tytso@mit.edu>2023-04-06 01:13:03 -0400
commitb07ffe6927c75d99af534d685282ea188d9f71a6 (patch)
tree5b18d8c8b296689625ceed3c701ea1e2dbdfe5f7 /fs/ext4/mballoc.c
parent1df9bde48fc6e8efe520f4d89ff35769b2c56b8b (diff)
ext4: set goal start correctly in ext4_mb_normalize_request
We need to set ac_g_ex to notify the goal start used in ext4_mb_find_by_goal. Set ac_g_ex instead of ac_f_ex in ext4_mb_normalize_request. Besides we should assure goal start is in range [first_data_block, blocks_count) as ext4_mb_initialize_context does. [ Added a check to make sure size is less than ar->pright; otherwise we could end up passing an underflowed value of ar->pright - size to ext4_get_group_no_and_offset(), which will trigger a BUG_ON later on. - TYT ] Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20230303172120.3800725-2-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/mballoc.c')
-rw-r--r--fs/ext4/mballoc.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 0d69cd8c5fc3..5a8fb0256752 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3993,6 +3993,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
struct ext4_allocation_request *ar)
{
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ struct ext4_super_block *es = sbi->s_es;
int bsbits, max;
ext4_lblk_t end;
loff_t size, start_off;
@@ -4188,18 +4189,21 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
/* define goal start in order to merge */
- if (ar->pright && (ar->lright == (start + size))) {
+ if (ar->pright && (ar->lright == (start + size)) &&
+ ar->pright >= size &&
+ ar->pright - size >= le32_to_cpu(es->s_first_data_block)) {
/* merge to the right */
ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
- &ac->ac_f_ex.fe_group,
- &ac->ac_f_ex.fe_start);
+ &ac->ac_g_ex.fe_group,
+ &ac->ac_g_ex.fe_start);
ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
}
- if (ar->pleft && (ar->lleft + 1 == start)) {
+ if (ar->pleft && (ar->lleft + 1 == start) &&
+ ar->pleft + 1 < ext4_blocks_count(es)) {
/* merge to the left */
ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
- &ac->ac_f_ex.fe_group,
- &ac->ac_f_ex.fe_start);
+ &ac->ac_g_ex.fe_group,
+ &ac->ac_g_ex.fe_start);
ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
}