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@xxxxxxxxxxxxxxx>
Suggested-by: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx>
---
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 799d2f0d465c..204b94717778 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4492,6 +4492,37 @@ 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
*/
@@ -4542,7 +4573,8 @@ 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);
--
2.30.0
