From 772c9f691dcf3a487f29ddb90a5a15c78d7328e1 Mon Sep 17 00:00:00 2001 From: Ritesh Harjani Date: Sun, 16 Jul 2023 19:33:34 +0530 Subject: ext4: don't use CR_BEST_AVAIL_LEN for non-regular files Using CR_BEST_AVAIL_LEN only make sense for regular files, as for non-regular files we never normalize the allocation request length i.e. goal len is same as original length (ac_g_ex.fe_len == ac_o_ex.fe_len). Hence there is no scope of trimming the goal length to make it satisfy original request len. Thus this patch avoids using CR_BEST_AVAIL_LEN criteria for non-regular files request. Cc: stable@kernel.org Fixes: 33122aa930f1 ("ext4: Add allocation criteria 1.5 (CR1_5)") Reported-by: Eric Whitney Signed-off-by: Ritesh Harjani (IBM) Tested-by: Eric Whitney Link: https://lore.kernel.org/r/2a694c748ff8b8c4b416995a24f06f07b55047a8.1689516047.git.ritesh.list@gmail.com Signed-off-by: Theodore Ts'o --- fs/ext4/mballoc.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index b89b5f0816e7..3d5b0b71d7f5 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -966,7 +966,18 @@ static void ext4_mb_choose_next_group_goal_fast(struct ext4_allocation_context * } } - *new_cr = CR_BEST_AVAIL_LEN; + /* + * CR_BEST_AVAIL_LEN works based on the concept that we have + * a larger normalized goal len request which can be trimmed to + * a smaller goal len such that it can still satisfy original + * request len. However, allocation request for non-regular + * files never gets normalized. + * See function ext4_mb_normalize_request() (EXT4_MB_HINT_DATA). + */ + if (ac->ac_flags & EXT4_MB_HINT_DATA) + *new_cr = CR_BEST_AVAIL_LEN; + else + *new_cr = CR_GOAL_LEN_SLOW; } /* -- cgit v1.2.3-58-ga151