This patch adds some more debugging mb_debug() msgs to help improve
mballoc code debugging.
Other than adding more mb_debug() msgs at few more places,
there should be no other functionality change in this patch.
Signed-off-by: Ritesh Harjani <[email protected]>
---
fs/ext4/mballoc.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index d1464d9110ef..2e4697e7b945 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2108,7 +2108,7 @@ static noinline_for_stack int
ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
{
ext4_group_t ngroups, group, i;
- int cr;
+ int cr = -1;
int err = 0, first_err = 0;
struct ext4_sb_info *sbi;
struct super_block *sb;
@@ -2260,6 +2260,10 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
out:
if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
err = first_err;
+
+ mb_debug(1, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
+ ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status,
+ ac->ac_flags, cr, err);
return err;
}
@@ -3918,7 +3922,7 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
mb_debug(1, "discard preallocation for group %u\n", group);
if (list_empty(&grp->bb_prealloc_list))
- return 0;
+ goto out_dbg;
bitmap_bh = ext4_read_block_bitmap(sb, group);
if (IS_ERR(bitmap_bh)) {
@@ -3926,7 +3930,7 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
ext4_error_err(sb, -err,
"Error %d reading block bitmap for %u",
err, group);
- return 0;
+ goto out_dbg;
}
err = ext4_mb_load_buddy(sb, group, &e4b);
@@ -3934,7 +3938,7 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
ext4_warning(sb, "Error %d loading buddy information for %u",
err, group);
put_bh(bitmap_bh);
- return 0;
+ goto out_dbg;
}
if (needed == 0)
@@ -3979,6 +3983,8 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
/* found anything to free? */
if (list_empty(&list)) {
BUG_ON(free != 0);
+ mb_debug(1, "Someone else may have freed PA for this group %u\n",
+ group);
goto out;
}
@@ -4003,6 +4009,9 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
ext4_unlock_group(sb, group);
ext4_mb_unload_buddy(&e4b);
put_bh(bitmap_bh);
+out_dbg:
+ mb_debug(1, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
+ free, group, grp->bb_free);
return free;
}
@@ -4538,6 +4547,7 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
ar->len = ar->len >> 1;
}
if (!ar->len) {
+ ext4_mb_show_pa(sb);
*errp = -ENOSPC;
return 0;
}
--
2.21.0