[Devel] [PATCH vz9] dm-ploop: fix resize and grow to use the new way of updating md pages
Konstantin Khorenko
khorenko at virtuozzo.com
Thu Mar 27 13:42:53 MSK 2025
Andrey, can you please review the patch?
Thank you.
--
Best regards,
Konstantin Khorenko,
Virtuozzo Linux Kernel Team
On 21.03.2025 16:37, Alexander Atanasov wrote:
> On 21.03.25 17:33, Konstantin Khorenko wrote:
>> Please, add reviewer to CC.
>
>
> Whomever is available, please, review.
>
>> --
>> Best regards,
>>
>> Konstantin Khorenko,
>> Virtuozzo Linux Kernel Team
>>
>> On 21.03.2025 16:17, Alexander Atanasov wrote:
>>> We missed the fact that resize/grow touch md0 page to update ploop
>>> parameters, other pages are not linked so there is no issue.
>>> But in case there is a concurrent update to md0 piwb is not handled
>>> correctly, also using sync updates in parallel is not okay.
>>> To fix this update code to use the new mechanism with MD_UPDATING
>>> flag and instead of using sync operations pass the updates to
>>> runner threads.
>>>
>>> https://virtuozzo.atlassian.net/browse/VSTOR-101871
>>> Signed-off-by: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
>>> ---
>>> drivers/md/dm-ploop-map.c | 37 ++++++++++++++++++++++++++++---------
>>> drivers/md/dm-ploop.h | 7 ++++++-
>>> 2 files changed, 34 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
>>> index ef280a8b0f90..04e71c851b64 100644
>>> --- a/drivers/md/dm-ploop-map.c
>>> +++ b/drivers/md/dm-ploop-map.c
>>> @@ -613,11 +613,6 @@ static void ploop_unlink_completed_pio(struct
>>> ploop *ploop, struct pio *pio)
>>> ploop_dispatch_pios(ploop, NULL, &pio_list);
>>> }
>>> -static void ploop_add_dirty_for_wb(struct ploop *ploop, struct
>>> md_page *md)
>>> -{
>>> - llist_add((struct llist_node *)&md->wb_link, &ploop-
>>>> wb_batch_llist);
>>> -}
>>> -
>>> static bool ploop_md_make_dirty(struct ploop *ploop, struct md_page
>>> *md)
>>> {
>>> bool new = false;
>>> @@ -1031,6 +1026,7 @@ static int ploop_prepare_bat_update(struct ploop
>>> *ploop, struct md_page *md,
>>> struct pio *pio;
>>> map_index_t *to;
>>> u8 level;
>>> + int ret = -ENOMEM;
>>> lockdep_assert_held(&ploop->bat_lock);
>>> @@ -1050,6 +1046,9 @@ static int ploop_prepare_bat_update(struct ploop
>>> *ploop, struct md_page *md,
>>> if (WARN_ON(md->piwb)) {
>>> PL_ERR("md %p has piwb: %p type:%d ourtype:%d\n",
>>> md, md->piwb, md->piwb->type, type);
>>> + spin_unlock(&md->md_lock);
>>> + ret = -EBUSY;
>>> + goto err;
>>> }
>>> md->piwb = piwb;
>>> piwb->md = md;
>>> @@ -1094,7 +1093,7 @@ static int ploop_prepare_bat_update(struct ploop
>>> *ploop, struct md_page *md,
>>> return 0;
>>> err:
>>> ploop_free_piwb(piwb);
>>> - return -ENOMEM;
>>> + return ret;
>>> }
>>> void ploop_break_bat_update(struct ploop *ploop, struct md_page *md,
>>> @@ -2692,31 +2691,45 @@ static void ploop_handle_cleanup(struct ploop
>>> *ploop, struct pio *pio)
>>> * another index instead of existing. If so, management of
>>> * old bat_entries[@clu] and of related holes_bitmap bit
>>> * is caller duty.
>>> + * Caller must clear MD_UPDATING and comply to add_for_wb
>>> */
>>> int ploop_prepare_reloc_index_wb(struct ploop *ploop,
>>> struct md_page **ret_md,
>>> u32 clu, u32 *dst_clu,
>>> - struct file *file)
>>> + struct file *file,
>>> + int *add_for_wb)
>>> {
>>> enum piwb_type type = PIWB_TYPE_ALLOC;
>>> u32 page_id = ploop_bat_clu_to_page_nr(clu);
>>> struct md_page *md = ploop_md_page_find(ploop, page_id);
>>> struct ploop_index_wb *piwb;
>>> int err;
>>> + bool add_to_wblist;
>>> if (dst_clu)
>>> type = PIWB_TYPE_RELOC;
>>> err = -EIO;
>>> +
>>> +
>>> spin_lock_irq(&ploop->bat_lock);
>>> - if (test_bit(MD_DIRTY, &md->status) || test_bit(MD_WRITEBACK,
>>> &md->status)) {
>>> - PL_ERR("Unexpected md status: %lx", md->status);
>>> + spin_lock(&md->md_lock);
>>> + if (test_bit(MD_DIRTY, &md->status) || test_bit(MD_WRITEBACK,
>>> &md->status)
>>> + || test_bit(MD_UPDATING, &md->status)) {
>>> + err = -EBUSY;
>>> + spin_unlock(&md->md_lock);
>>> goto out_error;
>>> + } else {
>>> + set_bit(MD_UPDATING, &md->status);
>>> }
>>> + spin_unlock(&md->md_lock);
>>> +
>>> err = ploop_prepare_bat_update(ploop, md, type);
>>> if (err)
>>> goto out_error;
>>> + add_to_wblist = ploop_md_make_dirty(ploop, md);
>>> +
>>> piwb = md->piwb;
>>> if (dst_clu) {
>>> @@ -2734,12 +2747,18 @@ int ploop_prepare_reloc_index_wb(struct ploop
>>> *ploop,
>>> spin_unlock_irq(&ploop->bat_lock);
>>> *ret_md = md;
>>> + *add_for_wb = add_to_wblist ? 1 : 0;
>>> +
>>> return 0;
>>> out_reset:
>>> ploop_break_bat_update(ploop, md, piwb);
>>> out_error:
>>> + if (add_to_wblist)
>>> + clear_bit(MD_DIRTY, &md->status);
>>> + clear_bit(MD_UPDATING, &md->status);
>>> spin_unlock_irq(&ploop->bat_lock);
>>> +
>>> return err;
>>> }
>>> ALLOW_ERROR_INJECTION(ploop_prepare_reloc_index_wb, ERRNO);
>>> diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
>>> index 46450cac8c7d..db4d92c9679a 100644
>>> --- a/drivers/md/dm-ploop.h
>>> +++ b/drivers/md/dm-ploop.h
>>> @@ -578,6 +578,11 @@ static inline const char
>>> *ploop_device_name(struct ploop *ploop)
>>> return ploop->ti->table->md->disk->disk_name;
>>> }
>>> +static inline void ploop_add_dirty_for_wb(struct ploop *ploop, struct
>>> md_page *md)
>>> +{
>>> + llist_add((struct llist_node *)&md->wb_link, &ploop-
>>>> wb_batch_llist);
>>> +}
>>> +
>>> #define PL_FMT(fmt) "ploop: %s: " fmt "\n"
>>> #define PL_ERR(fmt, ...) pr_err(PL_FMT(fmt),
>>> ploop_device_name(ploop), ##__VA_ARGS__)
>>> #define PL_ERR_ONCE(fmt, ...) pr_err_once(PL_FMT(fmt),
>>> ploop_device_name(ploop), ##__VA_ARGS__)
>>> @@ -612,7 +617,7 @@ extern void ploop_map_and_submit_rw(struct ploop
>>> *ploop, u32 dst_clu,
>>> struct pio *pio, u8 level);
>>> extern int ploop_prepare_reloc_index_wb(struct ploop *ploop,
>>> struct md_page **ret_md, u32 clu, u32 *dst_clu,
>>> - struct file *file);
>>> + struct file *file, int *add_for_wb);
>>> extern void ploop_break_bat_update(struct ploop *ploop, struct
>>> md_page *md,
>>> struct ploop_index_wb *piwb);
>>> extern void ploop_index_wb_submit(struct ploop *, struct
>>> ploop_index_wb *);
>
>
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