Commit 69bb0207 authored by Zhihao Cheng's avatar Zhihao Cheng
Browse files

ubi: fastmap: Fix missed ec updating after erasing old fastmap data block 

mainline inclusion
from mainline-v6.7-rc1
commit 4d18b5a57b16c21cf868369ca555068722c32b2d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9195H
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4d18b5a57b16c21cf868369ca555068722c32b2d



-------------------------------------------------

After running fsstress on ubifs for a long time, UBI(16384 blocks,
fastmap takes 2 blocks) has an erase block with different erase
counters displayed from two views:

From ubiscan view: PEB 8031 has erase counter 31581
=========================================================
from              to     count      min      avg      max
---------------------------------------------------------
0        ..        9:        0        0        0        0
10       ..       99:        0        0        0        0
100      ..      999:    16383      290      315      781
1000     ..     9999:        0        0        0        0
10000    ..    99999:        1    31581    31581    31581
100000   ..      inf:        0        0        0        0
---------------------------------------------------------
Total               :    16384      290      317    31581

From detailed_erase_block_info view: PEB 8031 has erase counter 7
physical_block_number   erase_count
8030                    421
8031                    7   # mem info is different from disk info
8032                    434
8033                    425
8034                    431

Following process missed updating erase counter in wl_entry(in memory):
ubi_update_fastmap
 for (i = 1; i < new_fm->used_blocks; i++) // update fastmap data
  if (!tmp_e)
   if (old_fm && old_fm->e[i])
    erase_block(ubi, old_fm->e[i]->pnum)
     ret = ubi_io_sync_erase(ubi, pnum, 0)
     ec = be64_to_cpu(ec_hdr->ec)
     ec += ret
     ec_hdr->ec = cpu_to_be64(ec)
     ubi_io_write_ec_hdr(ubi, pnum, ec_hdr)  // ec is updated on flash
   // ec is not updated in old_fm->e[i] (in memory)

Fix it by passing wl_enter into erase_block() and updating erase
counter in erase_block().

Fixes: dbb7d2a8 ("UBI: Add fastmap core")
Signed-off-by: default avatarZhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 41b5cf75

drivers/mtd/ubi/fastmap.c

+15 −10
Original line number Diff line number Diff line
@@ -1381,11 +1381,12 @@ static int ubi_write_fastmap(struct ubi_device *ubi, 
/**

 * erase_block - Manually erase a PEB.

 * @ubi: UBI device object

 * @pnum: PEB to be erased

 * @e: the physical eraseblock to erase

 *

 * Returns the new EC value on success, < 0 indicates an internal error.

 * This function returns zero in case of success and a negative error code in

 * case of failure.

 */

static int erase_block(struct ubi_device *ubi, int pnum)

static int erase_block(struct ubi_device *ubi, struct ubi_wl_entry *e)

{

	int ret;

	struct ubi_ec_hdr *ec_hdr;
@@ -1395,7 +1396,7 @@ static int erase_block(struct ubi_device *ubi, int pnum) 
	if (!ec_hdr)

		return -ENOMEM;



	ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);

	ret = ubi_io_read_ec_hdr(ubi, e->pnum, ec_hdr, 0);

	if (ret < 0)

		goto out;

	else if (ret && ret != UBI_IO_BITFLIPS) {
@@ -1403,7 +1404,7 @@ static int erase_block(struct ubi_device *ubi, int pnum) 
		goto out;

	}



	ret = ubi_io_sync_erase(ubi, pnum, 0);

	ret = ubi_io_sync_erase(ubi, e->pnum, 0);

	if (ret < 0)

		goto out;
@@ -1415,11 +1416,16 @@ static int erase_block(struct ubi_device *ubi, int pnum) 
	}



	ec_hdr->ec = cpu_to_be64(ec);

	ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);

	ret = ubi_io_write_ec_hdr(ubi, e->pnum, ec_hdr);

	if (ret < 0)

		goto out;



	ret = ec;

	e->ec = ec;

	spin_lock(&ubi->wl_lock);

	if (e->ec > ubi->max_ec)

		ubi->max_ec = e->ec;

	spin_unlock(&ubi->wl_lock);



out:

	kfree(ec_hdr);

	return ret;
@@ -1565,7 +1571,7 @@ int ubi_update_fastmap(struct ubi_device *ubi) 


		if (!tmp_e) {

			if (old_fm && old_fm->e[i]) {

				ret = erase_block(ubi, old_fm->e[i]->pnum);

				ret = erase_block(ubi, old_fm->e[i]);

				if (ret < 0) {

					ubi_err(ubi, "could not erase old fastmap PEB");
@@ -1617,7 +1623,7 @@ int ubi_update_fastmap(struct ubi_device *ubi) 
	if (old_fm) {

		/* no fresh anchor PEB was found, reuse the old one */

		if (!tmp_e) {

			ret = erase_block(ubi, old_fm->e[0]->pnum);

			ret = erase_block(ubi, old_fm->e[0]);

			if (ret < 0) {

				ubi_err(ubi, "could not erase old anchor PEB");
@@ -1629,7 +1635,6 @@ int ubi_update_fastmap(struct ubi_device *ubi) 
				goto err;

			}

			new_fm->e[0] = old_fm->e[0];

			new_fm->e[0]->ec = ret;

			old_fm->e[0] = NULL;

		} else {

			/* we've got a new anchor PEB, return the old one */