On 02/28/2017 02:22 AM, Shaohua Li wrote:
> On Tue, Feb 21, 2017 at 08:44:00PM +0100, Artur Paszkiewicz wrote:
>> Add a function to modify the log by removing an rdev when a drive fails
>> or adding when a spare/replacement is activated as a raid member.
>>
>> Removing a disk just clears the child log rdev pointer. No new stripes
>> will be accepted for this child log in ppl_write_stripe() and running io
>> units will be processed without writing PPL to the device.
>>
>> Adding a disk sets the child log rdev pointer and writes an empty PPL
>> header.
>>
>> Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx>
>> ---
>> drivers/md/raid5-ppl.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
>> drivers/md/raid5.c | 15 +++++++++++++++
>> drivers/md/raid5.h | 8 ++++++++
>> 3 files changed, 70 insertions(+)
>>
>> diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
>> index a7693353243a..c2070d124849 100644
>> --- a/drivers/md/raid5-ppl.c
>> +++ b/drivers/md/raid5-ppl.c
>> @@ -319,6 +319,12 @@ static void ppl_submit_iounit(struct ppl_io_unit *io)
>>
>> bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, ppl_conf->bs);
>> bio->bi_private = io;
>> +
>> + if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
>> + ppl_log_endio(bio);
>> + return;
>> + }
>> +
>> bio->bi_end_io = ppl_log_endio;
>> bio->bi_opf = REQ_OP_WRITE | REQ_FUA;
>> bio->bi_bdev = log->rdev->bdev;
>> @@ -1098,3 +1104,44 @@ int ppl_init_log(struct r5conf *conf)
>> ppl_exit_log(ppl_conf);
>> return ret;
>> }
>> +
>> +int ppl_modify_log(struct ppl_conf *ppl_conf, struct md_rdev *rdev,
>> + enum ppl_modify_log_operation operation)
>> +{
>> + struct ppl_log *log;
>> + int ret = 0;
>> + char b[BDEVNAME_SIZE];
>> +
>> + if (!rdev)
>> + return -EINVAL;
>> +
>> + pr_debug("%s: disk: %d operation: %s dev: %s\n",
>> + __func__, rdev->raid_disk,
>> + operation == PPL_MODIFY_LOG_DISK_REMOVE ? "remove" :
>> + (operation == PPL_MODIFY_LOG_DISK_ADD ? "add" : "?"),
>> + bdevname(rdev->bdev, b));
>> +
>> + if (rdev->raid_disk < 0)
>> + return 0;
>> +
>> + if (rdev->raid_disk >= ppl_conf->count)
>> + return -ENODEV;
>> +
>> + log = &ppl_conf->child_logs[rdev->raid_disk];
>> +
>> + mutex_lock(&log->io_mutex);
>> + if (operation == PPL_MODIFY_LOG_DISK_REMOVE) {
>> + log->rdev = NULL;
>> + } else if (operation == PPL_MODIFY_LOG_DISK_ADD) {
>> + ret = ppl_validate_rdev(rdev);
>> + if (!ret) {
>> + log->rdev = rdev;
>> + ret = ppl_write_empty_header(log);
>> + }
>> + } else {
>> + ret = -EINVAL;
>> + }
>> + mutex_unlock(&log->io_mutex);
>> +
>> + return ret;
>> +}
>> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
>> index 8b52392457d8..b17e90f06f19 100644
>> --- a/drivers/md/raid5.c
>> +++ b/drivers/md/raid5.c
>> @@ -7623,6 +7623,12 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
>> *rdevp = rdev;
>> }
>> }
>> + if (conf->ppl) {
>> + err = ppl_modify_log(conf->ppl, rdev,
>> + PPL_MODIFY_LOG_DISK_REMOVE);
>> + if (err)
>> + goto abort;
>> + }
>> if (p->replacement) {
>> /* We must have just cleared 'rdev' */
>> p->rdev = p->replacement;
>> @@ -7632,6 +7638,10 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
>> */
>> p->replacement = NULL;
>> clear_bit(WantReplacement, &rdev->flags);
>> +
>> + if (conf->ppl)
>> + err = ppl_modify_log(conf->ppl, p->rdev,
>> + PPL_MODIFY_LOG_DISK_ADD);
>> } else
>> /* We might have just removed the Replacement as faulty-
>> * clear the bit just in case
>> @@ -7695,6 +7705,11 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
>> if (rdev->saved_raid_disk != disk)
>> conf->fullsync = 1;
>> rcu_assign_pointer(p->rdev, rdev);
>> +
>> + if (conf->ppl)
>> + err = ppl_modify_log(conf->ppl, rdev,
>> + PPL_MODIFY_LOG_DISK_ADD);
>> +
>> goto out;
>> }
>> }
>> diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
>> index f915a7a0e752..43cfa5fa71b3 100644
>> --- a/drivers/md/raid5.h
>> +++ b/drivers/md/raid5.h
>> @@ -806,4 +806,12 @@ extern void ppl_exit_log(struct ppl_conf *log);
>> extern int ppl_write_stripe(struct ppl_conf *log, struct stripe_head *sh);
>> extern void ppl_write_stripe_run(struct ppl_conf *log);
>> extern void ppl_stripe_write_finished(struct stripe_head *sh);
>> +
>> +enum ppl_modify_log_operation {
>> + PPL_MODIFY_LOG_DISK_REMOVE,
>> + PPL_MODIFY_LOG_DISK_ADD,
>> +};
>
> a bool for this parameter is better
>
>> +extern int ppl_modify_log(struct ppl_conf *log, struct md_rdev *rdev,
>> + enum ppl_modify_log_operation operation);
>
> So this should be put into raid5-log.h and rename to log_modify_log(conf, xxx)
> or other sensible name.
OK, I will do that.
Thanks,
Artur
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