diff options
| author | Mathieu Othacehe <othacehe@gnu.org> | 2024-11-06 14:47:41 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2024-11-13 12:56:48 -0500 |
| commit | e06a8c24f6445c2f1b5255caa4f63b38e31c43fa (patch) | |
| tree | b851d6360453ab4ba7acd80f9153fddb14dc0000 /fs | |
| parent | d5e9836e13a53ef36af702d87ab20d1a126b0fb8 (diff) | |
ext4: prevent an infinite loop in the lazyinit thread
Use ktime_get_ns instead of ktime_get_real_ns when computing the lr_timeout
not to be affected by system time jumps.
Use a boolean instead of the MAX_JIFFY_OFFSET value to determine whether
the next_wakeup value has been set. Comparing elr->lr_next_sched to
MAX_JIFFY_OFFSET can cause the lazyinit thread to loop indefinitely.
Co-developed-by: Lukas Skupinski <lukas.skupinski@landisgyr.com>
Signed-off-by: Lukas Skupinski <lukas.skupinski@landisgyr.com>
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20241106134741.26948-2-othacehe@gnu.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/super.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 33a81ef3c08a..a09f4621b10d 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3719,12 +3719,12 @@ static int ext4_run_li_request(struct ext4_li_request *elr) ret = 1; if (!ret) { - start_time = ktime_get_real_ns(); + start_time = ktime_get_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) { - elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) * + elr->lr_timeout = nsecs_to_jiffies((ktime_get_ns() - start_time) * EXT4_SB(elr->lr_super)->s_li_wait_mult); } elr->lr_next_sched = jiffies + elr->lr_timeout; @@ -3784,8 +3784,9 @@ static int ext4_lazyinit_thread(void *arg) cont_thread: while (true) { - next_wakeup = MAX_JIFFY_OFFSET; + bool next_wakeup_initialized = false; + next_wakeup = 0; mutex_lock(&eli->li_list_mtx); if (list_empty(&eli->li_request_list)) { mutex_unlock(&eli->li_list_mtx); @@ -3798,8 +3799,11 @@ cont_thread: lr_request); if (time_before(jiffies, elr->lr_next_sched)) { - if (time_before(elr->lr_next_sched, next_wakeup)) + if (!next_wakeup_initialized || + time_before(elr->lr_next_sched, next_wakeup)) { next_wakeup = elr->lr_next_sched; + next_wakeup_initialized = true; + } continue; } if (down_read_trylock(&elr->lr_super->s_umount)) { @@ -3827,16 +3831,18 @@ cont_thread: elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ); } - if (time_before(elr->lr_next_sched, next_wakeup)) + if (!next_wakeup_initialized || + time_before(elr->lr_next_sched, next_wakeup)) { next_wakeup = elr->lr_next_sched; + next_wakeup_initialized = true; + } } mutex_unlock(&eli->li_list_mtx); try_to_freeze(); cur = jiffies; - if ((time_after_eq(cur, next_wakeup)) || - (MAX_JIFFY_OFFSET == next_wakeup)) { + if (!next_wakeup_initialized || time_after_eq(cur, next_wakeup)) { cond_resched(); continue; } |