diff options
author | Yu Kuai <yukuai3@huawei.com> | 2024-01-09 21:39:57 +0800 |
---|---|---|
committer | Song Liu <song@kernel.org> | 2024-01-09 10:08:18 -0800 |
commit | f9cfe7e7f96a9414a17d596e288693c4f2325d49 (patch) | |
tree | d27d6bd409d8a45cac4a4ec8cf563a3bf6f5bbf6 /drivers/md | |
parent | 53889bcaf536b3abedeaf104019877cee37dd08b (diff) |
md: Fix md_seq_ops() regressions
Commit cf1b6d4441ff ("md: simplify md_seq_ops") introduce following
regressions:
1) If list all_mddevs is emptly, personalities and unused devices won't
be showed to user anymore.
2) If seq_file buffer overflowed from md_seq_show(), then md_seq_start()
will be called again, hence personalities will be showed to user
again.
3) If seq_file buffer overflowed from md_seq_stop(), seq_read_iter()
doesn't handle this, hence unused devices won't be showed to user.
Fix above problems by printing personalities and unused devices in
md_seq_show().
Fixes: cf1b6d4441ff ("md: simplify md_seq_ops")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240109133957.2975272-1-yukuai1@huaweicloud.com
Diffstat (limited to 'drivers/md')
-rw-r--r-- | drivers/md/md.c | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index e351e6c51cc7..ff3057c787c1 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8135,6 +8135,19 @@ static void status_unused(struct seq_file *seq) seq_printf(seq, "\n"); } +static void status_personalities(struct seq_file *seq) +{ + struct md_personality *pers; + + seq_puts(seq, "Personalities : "); + spin_lock(&pers_lock); + list_for_each_entry(pers, &pers_list, list) + seq_printf(seq, "[%s] ", pers->name); + + spin_unlock(&pers_lock); + seq_puts(seq, "\n"); +} + static int status_resync(struct seq_file *seq, struct mddev *mddev) { sector_t max_sectors, resync, res; @@ -8276,20 +8289,10 @@ static int status_resync(struct seq_file *seq, struct mddev *mddev) static void *md_seq_start(struct seq_file *seq, loff_t *pos) __acquires(&all_mddevs_lock) { - struct md_personality *pers; - - seq_puts(seq, "Personalities : "); - spin_lock(&pers_lock); - list_for_each_entry(pers, &pers_list, list) - seq_printf(seq, "[%s] ", pers->name); - - spin_unlock(&pers_lock); - seq_puts(seq, "\n"); seq->poll_event = atomic_read(&md_event_count); - spin_lock(&all_mddevs_lock); - return seq_list_start(&all_mddevs, *pos); + return seq_list_start_head(&all_mddevs, *pos); } static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos) @@ -8300,16 +8303,23 @@ static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos) static void md_seq_stop(struct seq_file *seq, void *v) __releases(&all_mddevs_lock) { - status_unused(seq); spin_unlock(&all_mddevs_lock); } static int md_seq_show(struct seq_file *seq, void *v) { - struct mddev *mddev = list_entry(v, struct mddev, all_mddevs); + struct mddev *mddev; sector_t sectors; struct md_rdev *rdev; + if (v == &all_mddevs) { + status_personalities(seq); + if (list_empty(&all_mddevs)) + status_unused(seq); + return 0; + } + + mddev = list_entry(v, struct mddev, all_mddevs); if (!mddev_get(mddev)) return 0; @@ -8385,6 +8395,10 @@ static int md_seq_show(struct seq_file *seq, void *v) } spin_unlock(&mddev->lock); spin_lock(&all_mddevs_lock); + + if (mddev == list_last_entry(&all_mddevs, struct mddev, all_mddevs)) + status_unused(seq); + if (atomic_dec_and_test(&mddev->active)) __mddev_put(mddev); |