From: Kemeng Shi shikemeng@huaweicloud.com
[ Upstream commit 1eff590489a213a213c57d96b86f48b32cdf8c3a ]
ext4_mb_use_preallocated will ignore the demand to alloc goal blocks, although the EXT4_MB_HINT_GOAL_ONLY is requested. For group pa, ext4_mb_group_or_file will not set EXT4_MB_HINT_GROUP_ALLOC if EXT4_MB_HINT_GOAL_ONLY is set. So we will not alloc goal blocks from group pa if EXT4_MB_HINT_GOAL_ONLY is set. For inode pa, ext4_mb_pa_goal_check is added to check if free extent in found inode pa meets goal blocks when EXT4_MB_HINT_GOAL_ONLY is set.
Signed-off-by: Kemeng Shi shikemeng@huaweicloud.com Suggested-by: Ojaswin Mujoo ojaswin@linux.ibm.com Link: https://lore.kernel.org/r/20230603150327.3596033-6-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o tytso@mit.edu Stable-dep-of: 9d3de7ee192a ("ext4: fix rbtree traversal bug in ext4_mb_use_preallocated") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/mballoc.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index fd4d12c58c3b4..1f4d00a4308dc 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4528,6 +4528,37 @@ ext4_mb_check_group_pa(ext4_fsblk_t goal_block, return pa; }
+/* + * check if found pa meets EXT4_MB_HINT_GOAL_ONLY + */ +static bool +ext4_mb_pa_goal_check(struct ext4_allocation_context *ac, + struct ext4_prealloc_space *pa) +{ + struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); + ext4_fsblk_t start; + + if (likely(!(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))) + return true; + + /* + * If EXT4_MB_HINT_GOAL_ONLY is set, ac_g_ex will not be adjusted + * in ext4_mb_normalize_request and will keep same with ac_o_ex + * from ext4_mb_initialize_context. Choose ac_g_ex here to keep + * consistent with ext4_mb_find_by_goal. + */ + start = pa->pa_pstart + + (ac->ac_g_ex.fe_logical - pa->pa_lstart); + if (ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex) != start) + return false; + + if (ac->ac_g_ex.fe_len > pa->pa_len - + EXT4_B2C(sbi, ac->ac_g_ex.fe_logical - pa->pa_lstart)) + return false; + + return true; +} + /* * search goal blocks in preallocated space */ @@ -4578,7 +4609,8 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
/* found preallocated blocks, use them */ spin_lock(&tmp_pa->pa_lock); - if (tmp_pa->pa_deleted == 0 && tmp_pa->pa_free) { + if (tmp_pa->pa_deleted == 0 && tmp_pa->pa_free && + likely(ext4_mb_pa_goal_check(ac, tmp_pa))) { atomic_inc(&tmp_pa->pa_count); ext4_mb_use_inode_pa(ac, tmp_pa); spin_unlock(&tmp_pa->pa_lock);