From aa21b7e3d3205322d11dbced09941702ef308d8d Mon Sep 17 00:00:00 2001 From: Shaoying Xu Date: Thu, 2 Sep 2021 16:44:12 +0000 Subject: [PATCH] ext4: fix lazy initialization next schedule time computation in more granular unit commit 39fec6889d15a658c3a3ebb06fd69d3584ddffd3 upstream. Ext4 file system has default lazy inode table initialization setup once it is mounted. However, it has issue on computing the next schedule time that makes the timeout same amount in jiffies but different real time in secs if with various HZ values. Therefore, fix by measuring the current time in a more granular unit nanoseconds and make the next schedule time independent of the HZ value. Fixes: bfff68738f1c ("ext4: add support for lazy inode table initialization") Signed-off-by: Shaoying Xu Cc: stable@vger.kernel.org Signed-off-by: Theodore Ts'o Link: https://lore.kernel.org/r/20210902164412.9994-2-shaoyi@amazon.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 953c7e875783..b1af6588bad0 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3436,9 +3436,9 @@ static int ext4_run_li_request(struct ext4_li_request *elr) struct super_block *sb = elr->lr_super; ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; ext4_group_t group = elr->lr_next_group; - unsigned long timeout = 0; unsigned int prefetch_ios = 0; int ret = 0; + u64 start_time; if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) { elr->lr_next_group = ext4_mb_prefetch(sb, group, @@ -3475,14 +3475,13 @@ static int ext4_run_li_request(struct ext4_li_request *elr) ret = 1; if (!ret) { - timeout = jiffies; + start_time = ktime_get_real_ns(); ret = ext4_init_inode_table(sb, group, elr->lr_timeout ? 0 : 1); trace_ext4_lazy_itable_init(sb, group); if (elr->lr_timeout == 0) { - timeout = (jiffies - timeout) * - EXT4_SB(elr->lr_super)->s_li_wait_mult; - elr->lr_timeout = timeout; + elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) * + EXT4_SB(elr->lr_super)->s_li_wait_mult); } elr->lr_next_sched = jiffies + elr->lr_timeout; elr->lr_next_group = group + 1;