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 <1524155964-3743-3-git-send-email-hans.ml.holmberg@owltronix.com> <52CBD83E-784F-41E0-BB1E-CE12A93D015E@cnexlabs.com>
From:   Hans Holmberg <hans@owltronix.com>
Date:   Mon, 23 Apr 2018 15:41:40 +0300
Message-ID: <CANr-nt0_zrGT9Nxfy52mnxdbEA1wYj7q79Qqi_d5HmcPPVWqBg@mail.gmail.com>
Subject: Re: [PATCH 2/3] lightnvm: pblk: garbage collect lines with failed writes
To:     Javier Gonzalez <javier@cnexlabs.com>
Cc:     =?UTF-8?Q?Matias_Bj=C3=B8rling?= <mb@lightnvm.io>,
        "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Hans Holmberg <hans.holmberg@cnexlabs.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, Apr 20, 2018 at 9:49 PM, Javier Gonzalez <javier@cnexlabs.com> wrote:
>> On 19 Apr 2018, at 09.39, Hans Holmberg <hans.ml.holmberg@owltronix.com> wrote:
>>
>> From: Hans Holmberg <hans.holmberg@cnexlabs.com>
>>
>> Write failures should not happen under normal circumstances,
>> so in order to bring the chunk back into a known state as soon
>> as possible, evacuate all the valid data out of the line and let the
>> fw judge if the block can be written to in the next reset cycle.
>>
>> Do this by introducing a new gc list for lines with failed writes,
>> and ensure that the rate limiter allocates a small portion of
>> the write bandwidth to get the job done.
>>
>> The lba list is saved in memory for use during gc as we
>> cannot gurantee that the emeta data is readable if a write
>> error occurred.
>>
>> Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
>> ---
>> drivers/lightnvm/pblk-core.c  | 43 +++++++++++++++++++++--
>> drivers/lightnvm/pblk-gc.c    | 79 +++++++++++++++++++++++++++----------------
>> drivers/lightnvm/pblk-init.c  | 39 ++++++++++++++-------
>> drivers/lightnvm/pblk-rl.c    | 29 +++++++++++++---
>> drivers/lightnvm/pblk-sysfs.c | 15 ++++++--
>> drivers/lightnvm/pblk-write.c |  2 ++
>> drivers/lightnvm/pblk.h       | 25 +++++++++++---
>> 7 files changed, 178 insertions(+), 54 deletions(-)
>>
>> diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
>> index 7762e89..f6135e4 100644
>> --- a/drivers/lightnvm/pblk-core.c
>> +++ b/drivers/lightnvm/pblk-core.c
>> @@ -373,7 +373,13 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
>>
>>       lockdep_assert_held(&line->lock);
>>
>> -     if (!vsc) {
>> +     if (line->w_err_gc->has_write_err) {
>> +             if (line->gc_group != PBLK_LINEGC_WERR) {
>> +                     line->gc_group = PBLK_LINEGC_WERR;
>> +                     move_list = &l_mg->gc_werr_list;
>> +                     pblk_rl_werr_line_in(&pblk->rl);
>> +             }
>> +     } else if (!vsc) {
>>               if (line->gc_group != PBLK_LINEGC_FULL) {
>>                       line->gc_group = PBLK_LINEGC_FULL;
>>                       move_list = &l_mg->gc_full_list;
>> @@ -1603,8 +1609,13 @@ static void __pblk_line_put(struct pblk *pblk, struct pblk_line *line)
>>       line->state = PBLK_LINESTATE_FREE;
>>       line->gc_group = PBLK_LINEGC_NONE;
>>       pblk_line_free(line);
>> -     spin_unlock(&line->lock);
>>
>> +     if (line->w_err_gc->has_write_err) {
>> +             pblk_rl_werr_line_out(&pblk->rl);
>> +             line->w_err_gc->has_write_err = 0;
>> +     }
>> +
>> +     spin_unlock(&line->lock);
>>       atomic_dec(&gc->pipeline_gc);
>>
>>       spin_lock(&l_mg->free_lock);
>> @@ -1767,11 +1778,32 @@ void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line)
>>
>>       spin_lock(&l_mg->close_lock);
>>       spin_lock(&line->lock);
>> +
>> +     /* Update the in-memory start address for emeta, in case it has
>> +      * shifted due to write errors
>> +      */
>> +     if (line->emeta_ssec != line->cur_sec)
>> +             line->emeta_ssec = line->cur_sec;
>> +
>>       list_add_tail(&line->list, &l_mg->emeta_list);
>>       spin_unlock(&line->lock);
>>       spin_unlock(&l_mg->close_lock);
>>
>>       pblk_line_should_sync_meta(pblk);
>> +
>> +
>> +}
>> +
>> +static void pblk_save_lba_list(struct pblk *pblk, struct pblk_line *line)
>> +{
>> +     struct pblk_line_meta *lm = &pblk->lm;
>> +     unsigned int lba_list_size = lm->emeta_len[2];
>> +     struct pblk_w_err_gc *w_err_gc = line->w_err_gc;
>> +     struct pblk_emeta *emeta = line->emeta;
>> +
>> +     w_err_gc->lba_list = kmalloc(lba_list_size, GFP_KERNEL);
>> +     memcpy(w_err_gc->lba_list, emeta_to_lbas(pblk, emeta->buf),
>> +                             lba_list_size);
>> }
>>
>> void pblk_line_close_ws(struct work_struct *work)
>> @@ -1780,6 +1812,13 @@ void pblk_line_close_ws(struct work_struct *work)
>>                                                                       ws);
>>       struct pblk *pblk = line_ws->pblk;
>>       struct pblk_line *line = line_ws->line;
>> +     struct pblk_w_err_gc *w_err_gc = line->w_err_gc;
>> +
>> +     /* Write errors makes the emeta start address stored in smeta invalid,
>> +      * so keep a copy of the lba list until we've gc'd the line
>> +      */
>> +     if (w_err_gc->has_write_err)
>> +             pblk_save_lba_list(pblk, line);
>>
>>       pblk_line_close(pblk, line);
>>       mempool_free(line_ws, pblk->gen_ws_pool);
>> diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
>> index b0cc277..62f0548 100644
>> --- a/drivers/lightnvm/pblk-gc.c
>> +++ b/drivers/lightnvm/pblk-gc.c
>> @@ -138,10 +138,10 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
>>       struct pblk_line_mgmt *l_mg = &pblk->l_mg;
>>       struct pblk_line_meta *lm = &pblk->lm;
>>       struct pblk_gc *gc = &pblk->gc;
>> -     struct line_emeta *emeta_buf;
>> +     struct line_emeta *emeta_buf = NULL;
>>       struct pblk_line_ws *gc_rq_ws;
>>       struct pblk_gc_rq *gc_rq;
>> -     __le64 *lba_list;
>> +     __le64 *lba_list = NULL;
>>       unsigned long *invalid_bitmap;
>>       int sec_left, nr_secs, bit;
>>       int ret;
>> @@ -150,34 +150,42 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
>>       if (!invalid_bitmap)
>>               goto fail_free_ws;
>>
>> -     emeta_buf = pblk_malloc(lm->emeta_len[0], l_mg->emeta_alloc_type,
>> -                                                             GFP_KERNEL);
>> -     if (!emeta_buf) {
>> -             pr_err("pblk: cannot use GC emeta\n");
>> -             goto fail_free_bitmap;
>> -     }
>> -
>> -     ret = pblk_line_read_emeta(pblk, line, emeta_buf);
>> -     if (ret) {
>> -             pr_err("pblk: line %d read emeta failed (%d)\n", line->id, ret);
>> -             goto fail_free_emeta;
>> -     }
>> +     if (line->w_err_gc->has_write_err) {
>> +             lba_list = line->w_err_gc->lba_list;
>> +     } else {
>> +             emeta_buf = pblk_malloc(lm->emeta_len[0],
>> +                             l_mg->emeta_alloc_type, GFP_KERNEL);
>> +             if (!emeta_buf) {
>> +                     pr_err("pblk: cannot use GC emeta\n");
>> +                     goto fail_free_bitmap;
>> +             }
>>
>> -     /* If this read fails, it means that emeta is corrupted. For now, leave
>> -      * the line untouched. TODO: Implement a recovery routine that scans and
>> -      * moves all sectors on the line.
>> -      */
>> +             ret = pblk_line_read_emeta(pblk, line, emeta_buf);
>> +             if (ret) {
>> +                     pr_err("pblk: line %d read emeta failed (%d)\n",
>> +                                     line->id, ret);
>> +                     goto fail_free_emeta;
>> +             }
>>
>> -     ret = pblk_recov_check_emeta(pblk, emeta_buf);
>> -     if (ret) {
>> -             pr_err("pblk: inconsistent emeta (line %d)\n", line->id);
>> -             goto fail_free_emeta;
>> -     }
>> +             /* If this read fails, it means that emeta is corrupted.
>> +              * For now, leave the line untouched.
>> +              * TODO: Implement a recovery routine that scans and moves
>> +              * all sectors on the line.,
>> +              */
>> +
>> +             ret = pblk_recov_check_emeta(pblk, emeta_buf);
>> +             if (ret) {
>> +                     pr_err("pblk: inconsistent emeta (line %d)\n",
>> +                                     line->id);
>> +                     goto fail_free_emeta;
>> +             }
>>
>> -     lba_list = emeta_to_lbas(pblk, emeta_buf);
>> -     if (!lba_list) {
>> -             pr_err("pblk: could not interpret emeta (line %d)\n", line->id);
>> -             goto fail_free_emeta;
>> +             lba_list = emeta_to_lbas(pblk, emeta_buf);
>> +             if (!lba_list) {
>> +                     pr_err("pblk: could not interpret emeta (line %d)\n",
>> +                                     line->id);
>> +                     goto fail_free_emeta;
>> +             }
>>       }
>
>
> would it be an idea to make move all the logic above to a different
> function returning lba_list? This way, we do not have an extra indent
> for a single line use case.

Yes, indeed it would. I'll refactor this into a separate function.

>
>>
>>       spin_lock(&line->lock);
>> @@ -240,7 +248,12 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
>>               goto next_rq;
>>
>> out:
>> -     pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
>> +     if (line->w_err_gc->has_write_err) {
>> +             kfree(lba_list);
>> +             line->w_err_gc->lba_list = NULL;
>> +     } else
>> +             pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
>> +
>>       kfree(line_ws);
>>       kfree(invalid_bitmap);
>>
>> @@ -252,7 +265,11 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
>> fail_free_gc_rq:
>>       kfree(gc_rq);
>> fail_free_emeta:
>> -     pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
>> +     if (line->w_err_gc->has_write_err) {
>> +             kfree(lba_list);
>> +             line->w_err_gc->lba_list = NULL;
>> +     } else
>> +             pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
>
> Can you open/close brackets here too?

I'll tidy this up along with the refactoring mentioned above.

>
>> fail_free_bitmap:
>>       kfree(invalid_bitmap);
>> fail_free_ws:
>> @@ -349,12 +366,14 @@ static struct pblk_line *pblk_gc_get_victim_line(struct pblk *pblk,
>> static bool pblk_gc_should_run(struct pblk_gc *gc, struct pblk_rl *rl)
>> {
>>       unsigned int nr_blocks_free, nr_blocks_need;
>> +     unsigned int werr_lines = atomic_read(&rl->werr_lines);
>>
>>       nr_blocks_need = pblk_rl_high_thrs(rl);
>>       nr_blocks_free = pblk_rl_nr_free_blks(rl);
>>
>>       /* This is not critical, no need to take lock here */
>> -     return ((gc->gc_active) && (nr_blocks_need > nr_blocks_free));
>> +     return ((werr_lines > 0) ||
>> +             ((gc->gc_active) && (nr_blocks_need > nr_blocks_free)));
>> }
>>
>> void pblk_gc_free_full_lines(struct pblk *pblk)
>> diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
>> index 6f06727..092e361 100644
>> --- a/drivers/lightnvm/pblk-init.c
>> +++ b/drivers/lightnvm/pblk-init.c
>> @@ -495,9 +495,14 @@ static void pblk_line_mg_free(struct pblk *pblk)
>>
>> static void pblk_line_meta_free(struct pblk_line *line)
>> {
>> +     struct pblk_w_err_gc *w_err_gc = line->w_err_gc;
>> +
>>       kfree(line->blk_bitmap);
>>       kfree(line->erase_bitmap);
>>       kfree(line->chks);
>> +
>> +     kfree(w_err_gc->lba_list);
>> +     kfree(w_err_gc);
>> }
>>
>> static void pblk_lines_free(struct pblk *pblk)
>> @@ -813,20 +818,28 @@ static int pblk_alloc_line_meta(struct pblk *pblk, struct pblk_line *line)
>>               return -ENOMEM;
>>
>>       line->erase_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
>> -     if (!line->erase_bitmap) {
>> -             kfree(line->blk_bitmap);
>> -             return -ENOMEM;
>> -     }
>> +     if (!line->erase_bitmap)
>> +             goto free_blk_bitmap;
>> +
>>
>>       line->chks = kmalloc(lm->blk_per_line * sizeof(struct nvm_chk_meta),
>>                                                               GFP_KERNEL);
>> -     if (!line->chks) {
>> -             kfree(line->erase_bitmap);
>> -             kfree(line->blk_bitmap);
>> -             return -ENOMEM;
>> -     }
>> +     if (!line->chks)
>> +             goto free_erase_bitmap;
>> +
>> +     line->w_err_gc = kzalloc(sizeof(struct pblk_w_err_gc), GFP_KERNEL);
>> +     if (!line->w_err_gc)
>> +             goto free_chks;
>>
>>       return 0;
>> +
>> +free_chks:
>> +     kfree(line->chks);
>> +free_erase_bitmap:
>> +     kfree(line->erase_bitmap);
>> +free_blk_bitmap:
>> +     kfree(line->blk_bitmap);
>> +     return -ENOMEM;
>> }
>>
>> static int pblk_line_mg_init(struct pblk *pblk)
>> @@ -851,12 +864,14 @@ static int pblk_line_mg_init(struct pblk *pblk)
>>       INIT_LIST_HEAD(&l_mg->gc_mid_list);
>>       INIT_LIST_HEAD(&l_mg->gc_low_list);
>>       INIT_LIST_HEAD(&l_mg->gc_empty_list);
>> +     INIT_LIST_HEAD(&l_mg->gc_werr_list);
>>
>>       INIT_LIST_HEAD(&l_mg->emeta_list);
>>
>> -     l_mg->gc_lists[0] = &l_mg->gc_high_list;
>> -     l_mg->gc_lists[1] = &l_mg->gc_mid_list;
>> -     l_mg->gc_lists[2] = &l_mg->gc_low_list;
>> +     l_mg->gc_lists[0] = &l_mg->gc_werr_list;
>> +     l_mg->gc_lists[1] = &l_mg->gc_high_list;
>> +     l_mg->gc_lists[2] = &l_mg->gc_mid_list;
>> +     l_mg->gc_lists[3] = &l_mg->gc_low_list;
>>
>>       spin_lock_init(&l_mg->free_lock);
>>       spin_lock_init(&l_mg->close_lock);
>> diff --git a/drivers/lightnvm/pblk-rl.c b/drivers/lightnvm/pblk-rl.c
>> index 883a711..6a0616a 100644
>> --- a/drivers/lightnvm/pblk-rl.c
>> +++ b/drivers/lightnvm/pblk-rl.c
>> @@ -73,6 +73,16 @@ void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries)
>>       pblk_rl_kick_u_timer(rl);
>> }
>>
>> +void pblk_rl_werr_line_in(struct pblk_rl *rl)
>> +{
>> +     atomic_inc(&rl->werr_lines);
>> +}
>> +
>> +void pblk_rl_werr_line_out(struct pblk_rl *rl)
>> +{
>> +     atomic_dec(&rl->werr_lines);
>> +}
>> +
>> void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries)
>> {
>>       atomic_add(nr_entries, &rl->rb_gc_cnt);
>> @@ -99,11 +109,21 @@ static void __pblk_rl_update_rates(struct pblk_rl *rl,
>> {
>>       struct pblk *pblk = container_of(rl, struct pblk, rl);
>>       int max = rl->rb_budget;
>> +     int werr_gc_needed = atomic_read(&rl->werr_lines);
>>
>>       if (free_blocks >= rl->high) {
>> -             rl->rb_user_max = max;
>> -             rl->rb_gc_max = 0;
>> -             rl->rb_state = PBLK_RL_HIGH;
>> +             if (werr_gc_needed) {
>> +                     /* Allocate a small budget for recovering
>> +                      * lines with write errors
>> +                      */
>> +                     rl->rb_gc_max = 1 << rl->rb_windows_pw;
>> +                     rl->rb_user_max = max - rl->rb_gc_max;
>> +                     rl->rb_state = PBLK_RL_WERR;
>> +             } else {
>> +                     rl->rb_user_max = max;
>> +                     rl->rb_gc_max = 0;
>> +                     rl->rb_state = PBLK_RL_OFF;
>> +             }
>>       } else if (free_blocks < rl->high) {
>>               int shift = rl->high_pw - rl->rb_windows_pw;
>>               int user_windows = free_blocks >> shift;
>> @@ -124,7 +144,7 @@ static void __pblk_rl_update_rates(struct pblk_rl *rl,
>>               rl->rb_state = PBLK_RL_LOW;
>>       }
>>
>> -     if (rl->rb_state == (PBLK_RL_MID | PBLK_RL_LOW))
>> +     if (rl->rb_state != PBLK_RL_OFF)
>>               pblk_gc_should_start(pblk);
>>       else
>>               pblk_gc_should_stop(pblk);
>> @@ -221,6 +241,7 @@ void pblk_rl_init(struct pblk_rl *rl, int budget)
>>       atomic_set(&rl->rb_user_cnt, 0);
>>       atomic_set(&rl->rb_gc_cnt, 0);
>>       atomic_set(&rl->rb_space, -1);
>> +     atomic_set(&rl->werr_lines, 0);
>>
>>       timer_setup(&rl->u_timer, pblk_rl_u_timer, 0);
>>
>> diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
>> index e61909a..88a0a7c 100644
>> --- a/drivers/lightnvm/pblk-sysfs.c
>> +++ b/drivers/lightnvm/pblk-sysfs.c
>> @@ -173,6 +173,8 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
>>       int free_line_cnt = 0, closed_line_cnt = 0, emeta_line_cnt = 0;
>>       int d_line_cnt = 0, l_line_cnt = 0;
>>       int gc_full = 0, gc_high = 0, gc_mid = 0, gc_low = 0, gc_empty = 0;
>> +     int gc_werr = 0;
>> +
>>       int bad = 0, cor = 0;
>>       int msecs = 0, cur_sec = 0, vsc = 0, sec_in_line = 0;
>>       int map_weight = 0, meta_weight = 0;
>> @@ -237,6 +239,15 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
>>               gc_empty++;
>>       }
>>
>> +     list_for_each_entry(line, &l_mg->gc_werr_list, list) {
>> +             if (line->type == PBLK_LINETYPE_DATA)
>> +                     d_line_cnt++;
>> +             else if (line->type == PBLK_LINETYPE_LOG)
>> +                     l_line_cnt++;
>> +             closed_line_cnt++;
>> +             gc_werr++;
>> +     }
>> +
>>       list_for_each_entry(line, &l_mg->bad_list, list)
>>               bad++;
>>       list_for_each_entry(line, &l_mg->corrupt_list, list)
>> @@ -275,8 +286,8 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
>>                                       l_mg->nr_lines);
>>
>>       sz += snprintf(page + sz, PAGE_SIZE - sz,
>> -             "GC: full:%d, high:%d, mid:%d, low:%d, empty:%d, queue:%d\n",
>> -                     gc_full, gc_high, gc_mid, gc_low, gc_empty,
>> +             "GC: full:%d, high:%d, mid:%d, low:%d, empty:%d, werr: %d, queue:%d\n",
>> +                     gc_full, gc_high, gc_mid, gc_low, gc_empty, gc_werr,
>>                       atomic_read(&pblk->gc.read_inflight_gc));
>>
>>       sz += snprintf(page + sz, PAGE_SIZE - sz,
>> diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
>> index ab45157..3b6bead 100644
>> --- a/drivers/lightnvm/pblk-write.c
>> +++ b/drivers/lightnvm/pblk-write.c
>> @@ -136,6 +136,7 @@ static void pblk_map_remaining(struct pblk *pblk, struct ppa_addr *ppa)
>>               }
>>       }
>>
>> +     line->w_err_gc->has_write_err = 1;
>>       spin_unlock(&line->lock);
>> }
>>
>> @@ -277,6 +278,7 @@ static void pblk_end_io_write_meta(struct nvm_rq *rqd)
>>       if (rqd->error) {
>>               pblk_log_write_err(pblk, rqd);
>>               pr_err("pblk: metadata I/O failed. Line %d\n", line->id);
>> +             line->w_err_gc->has_write_err = 1;
>>       }
>>
>>       sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
>> diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
>> index cff6aea..a4e55d8 100644
>> --- a/drivers/lightnvm/pblk.h
>> +++ b/drivers/lightnvm/pblk.h
>> @@ -89,12 +89,14 @@ struct pblk_sec_meta {
>> /* The number of GC lists and the rate-limiter states go together. This way the
>>  * rate-limiter can dictate how much GC is needed based on resource utilization.
>>  */
>> -#define PBLK_GC_NR_LISTS 3
>> +#define PBLK_GC_NR_LISTS 4
>>
>> enum {
>> -     PBLK_RL_HIGH = 1,
>> -     PBLK_RL_MID = 2,
>> -     PBLK_RL_LOW = 3,
>> +     PBLK_RL_OFF = 0,
>> +     PBLK_RL_WERR = 1,
>> +     PBLK_RL_HIGH = 2,
>> +     PBLK_RL_MID = 3,
>> +     PBLK_RL_LOW = 4
>> };
>>
>> #define pblk_dma_meta_size (sizeof(struct pblk_sec_meta) * PBLK_MAX_REQ_ADDRS)
>> @@ -278,6 +280,8 @@ struct pblk_rl {
>>       int rb_user_active;
>>       int rb_gc_active;
>>
>> +     atomic_t werr_lines;    /* Number of write error lines that needs gc */
>> +
>>       struct timer_list u_timer;
>>
>>       unsigned long long nr_secs;
>> @@ -311,6 +315,7 @@ enum {
>>       PBLK_LINEGC_MID = 23,
>>       PBLK_LINEGC_HIGH = 24,
>>       PBLK_LINEGC_FULL = 25,
>> +     PBLK_LINEGC_WERR = 26
>> };
>>
>> #define PBLK_MAGIC 0x70626c6b /*pblk*/
>> @@ -412,6 +417,11 @@ struct pblk_smeta {
>>       struct line_smeta *buf;         /* smeta buffer in persistent format */
>> };
>>
>> +struct pblk_w_err_gc {
>> +     int has_write_err;
>> +     __le64 *lba_list;
>> +};
>> +
>> struct pblk_line {
>>       struct pblk *pblk;
>>       unsigned int id;                /* Line number corresponds to the
>> @@ -457,6 +467,8 @@ struct pblk_line {
>>
>>       struct kref ref;                /* Write buffer L2P references */
>>
>> +     struct pblk_w_err_gc *w_err_gc; /* Write error gc recovery metadata */
>> +
>>       spinlock_t lock;                /* Necessary for invalid_bitmap only */
>> };
>>
>> @@ -488,6 +500,8 @@ struct pblk_line_mgmt {
>>       struct list_head gc_mid_list;   /* Full lines ready to GC, mid isc */
>>       struct list_head gc_low_list;   /* Full lines ready to GC, low isc */
>>
>> +     struct list_head gc_werr_list;  /* Write err recovery list */
>> +
>>       struct list_head gc_full_list;  /* Full lines ready to GC, no valid */
>>       struct list_head gc_empty_list; /* Full lines close, all valid */
>>
>> @@ -894,6 +908,9 @@ void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line,
>>                           bool used);
>> int pblk_rl_is_limit(struct pblk_rl *rl);
>>
>> +void pblk_rl_werr_line_in(struct pblk_rl *rl);
>> +void pblk_rl_werr_line_out(struct pblk_rl *rl);
>> +
>> /*
>>  * pblk sysfs
>>  */
>> --
>> 2.7.4
>
> Otherwise, it looks good to me

Great, thanks.

>
> Javier