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From: Zhihao Cheng <chengzhihao1@huawei.com>
To: Richard Weinberger <richard@nod.at>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	mcoquelin stm32 <mcoquelin.stm32@gmail.com>,
	"kirill shutemov" <kirill.shutemov@linux.intel.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 12/15] ubi: fastmap: Add all fastmap pebs into 'ai->fastmap' when fm->used_blocks>=2
Date: Tue, 11 Jan 2022 19:44:49 +0800	[thread overview]
Message-ID: <420c7567-8926-2e8b-4da0-a9bfc8379642@huawei.com> (raw)
In-Reply-To: <244238061.248369.1641886066066.JavaMail.zimbra@nod.at>

Hi Richard,
> In ubi_wl_init() there is another corner case documented:
>                          /*
>                           * The fastmap update code might not find a free PEB for
>                           * writing the fastmap anchor to and then reuses the
>                           * current fastmap anchor PEB. When this PEB gets erased
>                           * and a power cut happens before it is written again we
>                           * must make sure that the fastmap attach code doesn't
>                           * find any outdated fastmap anchors, hence we erase the
>                           * outdated fastmap anchor PEBs synchronously here.
>                           */
>                          if (aeb->vol_id == UBI_FM_SB_VOLUME_ID)
>                                  sync = true;
> 
> So ubi_wl_init() makes sure that all old fastmap anchors get erased before UBI
> starts to operate. With your change this is no longer satisfied
I seem to understand the another case. But I'm still confused that why 
outdated fastmap PEBs cannot be erased. When UBI comes to this point, it 
means UBI is attached by **full scanning mode**, scan_fast() returns two 
values:
   UBI_NO_FASTMAP: scan all pebs from pnum UBI_FM_MAX_START, ai is 
assigned with scan_ai, at last, all fastmap pebs are added into 
'ai->fastmap'
   UBI_BAD_FASTMAP: scan all pebs from pnum 0, all fastmap pebs are 
added into 'ai->fastmap'

WARNING: multiple messages have this Message-ID (diff)
From: Zhihao Cheng <chengzhihao1@huawei.com>
To: Richard Weinberger <richard@nod.at>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	mcoquelin stm32 <mcoquelin.stm32@gmail.com>,
	"kirill shutemov" <kirill.shutemov@linux.intel.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 12/15] ubi: fastmap: Add all fastmap pebs into 'ai->fastmap' when fm->used_blocks>=2
Date: Tue, 11 Jan 2022 19:44:49 +0800	[thread overview]
Message-ID: <420c7567-8926-2e8b-4da0-a9bfc8379642@huawei.com> (raw)
In-Reply-To: <244238061.248369.1641886066066.JavaMail.zimbra@nod.at>

Hi Richard,
> In ubi_wl_init() there is another corner case documented:
>                          /*
>                           * The fastmap update code might not find a free PEB for
>                           * writing the fastmap anchor to and then reuses the
>                           * current fastmap anchor PEB. When this PEB gets erased
>                           * and a power cut happens before it is written again we
>                           * must make sure that the fastmap attach code doesn't
>                           * find any outdated fastmap anchors, hence we erase the
>                           * outdated fastmap anchor PEBs synchronously here.
>                           */
>                          if (aeb->vol_id == UBI_FM_SB_VOLUME_ID)
>                                  sync = true;
> 
> So ubi_wl_init() makes sure that all old fastmap anchors get erased before UBI
> starts to operate. With your change this is no longer satisfied
I seem to understand the another case. But I'm still confused that why 
outdated fastmap PEBs cannot be erased. When UBI comes to this point, it 
means UBI is attached by **full scanning mode**, scan_fast() returns two 
values:
   UBI_NO_FASTMAP: scan all pebs from pnum UBI_FM_MAX_START, ai is 
assigned with scan_ai, at last, all fastmap pebs are added into 
'ai->fastmap'
   UBI_BAD_FASTMAP: scan all pebs from pnum 0, all fastmap pebs are 
added into 'ai->fastmap'

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  reply	other threads:[~2022-01-11 11:44 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-27  3:22 [PATCH v6 00/15] Some bugfixs for ubi/ubifs Zhihao Cheng
2021-12-27  3:22 ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 01/15] ubifs: rename_whiteout: Fix double free for whiteout_ui->data Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 02/15] ubifs: Fix deadlock in concurrent rename whiteout and inode writeback Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 03/15] ubifs: Fix wrong number of inodes locked by ui_mutex in ubifs_inode comment Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 04/15] ubifs: Add missing iput if do_tmpfile() failed in rename whiteout Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 05/15] ubifs: Rename whiteout atomically Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2022-01-09 21:14   ` Richard Weinberger
2022-01-09 21:14     ` Richard Weinberger
2022-01-10  9:35     ` Zhihao Cheng
2022-01-10  9:35       ` Zhihao Cheng
2022-01-10 10:14       ` Richard Weinberger
2022-01-10 10:14         ` Richard Weinberger
2022-01-10 20:58         ` Richard Weinberger
2022-01-10 20:58           ` Richard Weinberger
2021-12-27  3:22 ` [PATCH v6 06/15] ubifs: Fix 'ui->dirty' race between do_tmpfile() and writeback work Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 07/15] ubifs: Rectify space amount budget for mkdir/tmpfile operations Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 08/15] ubifs: setflags: Make dirtied_ino_d 8 bytes aligned Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 09/15] ubifs: Fix read out-of-bounds in ubifs_wbuf_write_nolock() Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 10/15] ubifs: Fix to add refcount once page is set private Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 11/15] ubi: fastmap: Return error code if memory allocation fails in add_aeb() Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 12/15] ubi: fastmap: Add all fastmap pebs into 'ai->fastmap' when fm->used_blocks>=2 Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2022-01-10 23:23   ` Richard Weinberger
2022-01-10 23:23     ` Richard Weinberger
2022-01-11  2:48     ` Zhihao Cheng
2022-01-11  2:48       ` Zhihao Cheng
2022-01-11  7:27       ` Richard Weinberger
2022-01-11  7:27         ` Richard Weinberger
2022-01-11 11:44         ` Zhihao Cheng [this message]
2022-01-11 11:44           ` Zhihao Cheng
2022-01-11 11:57           ` Richard Weinberger
2022-01-11 11:57             ` Richard Weinberger
2022-01-11 13:23             ` Zhihao Cheng
2022-01-11 13:23               ` Zhihao Cheng
2022-01-11 13:56               ` Richard Weinberger
2022-01-11 13:56                 ` Richard Weinberger
2022-01-12  3:46                 ` Zhihao Cheng
2022-01-12  3:46                   ` Zhihao Cheng
2022-01-14 18:45                   ` Richard Weinberger
2022-01-14 18:45                     ` Richard Weinberger
2022-01-15  8:22                     ` Zhihao Cheng
2022-01-15  8:22                       ` Zhihao Cheng
2022-01-15  8:46                       ` Zhihao Cheng
2022-01-15  8:46                         ` Zhihao Cheng
2022-01-15 10:01                         ` Richard Weinberger
2022-01-15 10:01                           ` Richard Weinberger
2022-01-17  1:31                           ` Zhihao Cheng
2022-01-17  1:31                             ` Zhihao Cheng
2022-01-17  2:52                             ` Zhihao Cheng
2022-01-17  2:52                               ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 13/15] ubifs: ubifs_writepage: Mark page dirty after writing inode failed Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 14/15] ubifs: ubifs_releasepage: Remove ubifs_assert(0) to valid this process Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2021-12-27  3:22 ` [PATCH v6 15/15] ubi: fastmap: Fix high cpu usage of ubi_bgt by making sure wl_pool not empty Zhihao Cheng
2021-12-27  3:22   ` Zhihao Cheng
2022-01-17  1:40   ` Zhihao Cheng
2022-01-17  1:40     ` Zhihao Cheng
2021-12-27 10:13 ` [PATCH v6 00/15] Some bugfixs for ubi/ubifs Richard Weinberger
2021-12-27 10:13   ` Richard Weinberger
2021-12-27 12:19   ` Zhihao Cheng
2021-12-27 12:19     ` Zhihao Cheng
2021-12-27 13:00     ` Richard Weinberger
2021-12-27 13:00       ` Richard Weinberger

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