pstore/zone: Provide way to skip "broken" zone for MTD devices (335426c6) · Commits · 戴 / test

fs/pstore/blk.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -109,9 +109,12 @@ struct bdev_info {
		* means error.
		* @write: The same as @read, but the following error number:
		* -EBUSY means try to write again later.
		* -ENOMSG means to try next zone.
		* @panic_write:The write operation only used for panic case. It's optional
		* if you do not care panic log. The parameters and return value
		* are the same as @read.
		* if you do not care panic log. The parameters are relative
		* value to storage.
		* On success, the number of bytes should be returned, others
		* excluding -ENOMSG mean error. -ENOMSG means to try next zone.
		*/
		struct pstore_device_info {
		unsigned long total_size;
		@@ -337,6 +340,9 @@ static ssize_t psblk_blk_panic_write(const char *buf, size_t size,
		/* size and off must align to SECTOR_SIZE for block device */
		ret = blkdev_panic_write(buf, off >> SECTOR_SHIFT,
		size >> SECTOR_SHIFT);
		/* try next zone */
		if (ret == -ENOMSG)
		return ret;
		return ret ? -EIO : size;
		}

fs/pstore/zone.c

+53 −12

Original line number	Diff line number	Diff line
		@@ -249,6 +249,9 @@ static int psz_zone_write(struct pstore_zone *zone,

		return 0;
		dirty:
		/* no need to mark dirty if going to try next zone */
		if (wcnt == -ENOMSG)
		return -ENOMSG;
		atomic_set(&zone->dirty, true);
		/* flush dirty zones nicely */
		if (wcnt == -EBUSY && !is_on_panic())
		@@ -391,7 +394,11 @@ static int psz_kmsg_recover_meta(struct psz_context *cxt)
		return -EINVAL;

		rcnt = info->read((char *)buf, len, zone->off);
		if (rcnt != len) {
		if (rcnt == -ENOMSG) {
		pr_debug("%s with id %lu may be broken, skip\n",
		zone->name, i);
		continue;
		} else if (rcnt != len) {
		pr_err("read %s with id %lu failed\n", zone->name, i);
		return (int)rcnt < 0 ? (int)rcnt : -EIO;
		}
		@@ -725,24 +732,58 @@ static void psz_write_kmsg_hdr(struct pstore_zone *zone,
		hdr->counter = 0;
		}

		/*
		* In case zone is broken, which may occur to MTD device, we try each zones,
		* start at cxt->kmsg_write_cnt.
		*/
		static inline int notrace psz_kmsg_write_record(struct psz_context *cxt,
		struct pstore_record *record)
		{
		size_t size, hlen;
		struct pstore_zone *zone;
		unsigned int zonenum;
		unsigned int i;

		zonenum = cxt->kmsg_write_cnt;
		for (i = 0; i < cxt->kmsg_max_cnt; i++) {
		unsigned int zonenum, len;
		int ret;

		zonenum = (cxt->kmsg_write_cnt + i) % cxt->kmsg_max_cnt;
		zone = cxt->kpszs[zonenum];
		if (unlikely(!zone))
		return -ENOSPC;
		cxt->kmsg_write_cnt = (zonenum + 1) % cxt->kmsg_max_cnt;

		/* avoid destroying old data, allocate a new one */
		len = zone->buffer_size + sizeof(*zone->buffer);
		zone->oldbuf = zone->buffer;
		zone->buffer = kzalloc(len, GFP_KERNEL);
		if (!zone->buffer) {
		zone->buffer = zone->oldbuf;
		return -ENOMEM;
		}
		zone->buffer->sig = zone->oldbuf->sig;

		pr_debug("write %s to zone id %d\n", zone->name, zonenum);
		psz_write_kmsg_hdr(zone, record);
		hlen = sizeof(struct psz_kmsg_header);
		size = min_t(size_t, record->size, zone->buffer_size - hlen);
		return psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen);
		ret = psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen);
		if (likely(!ret \|\| ret != -ENOMSG)) {
		cxt->kmsg_write_cnt = zonenum + 1;
		cxt->kmsg_write_cnt %= cxt->kmsg_max_cnt;
		/* no need to try next zone, free last zone buffer */
		kfree(zone->oldbuf);
		zone->oldbuf = NULL;
		return ret;
		}

		pr_debug("zone %u may be broken, try next dmesg zone\n",
		zonenum);
		kfree(zone->buffer);
		zone->buffer = zone->oldbuf;
		zone->oldbuf = NULL;
		}

		return -EBUSY;
		}

		static int notrace psz_kmsg_write(struct psz_context *cxt,

include/linux/pstore_blk.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -14,7 +14,8 @@
		* @start_sect: start sector to block device
		* @sects: sectors count on buf
		*
		* Return: On success, zero should be returned. Others mean error.
		* Return: On success, zero should be returned. Others excluding -ENOMSG
		* mean error. -ENOMSG means to try next zone.
		*
		* Panic write to block device must be aligned to SECTOR_SIZE.
		*/

include/linux/pstore_zone.h

+8 −4

Original line number	Diff line number	Diff line
		@@ -23,11 +23,15 @@ typedef ssize_t (pstore_zone_write_op)(const char , size_t, loff_t);
		* @read: The general read operation. Both of the function parameters
		* @size and @offset are relative value to storage.
		* On success, the number of bytes should be returned, others
		* means error.
		* @write: The same as @read, but -EBUSY means try to write again later.
		* mean error.
		* @write: The same as @read, but the following error number:
		* -EBUSY means try to write again later.
		* -ENOMSG means to try next zone.
		* @panic_write:The write operation only used for panic case. It's optional
		* if you do not care panic log. The parameters and return value
		* are the same as @read.
		* if you do not care panic log. The parameters are relative
		* value to storage.
		* On success, the number of bytes should be returned, others
		* excluding -ENOMSG mean error. -ENOMSG means to try next zone.
		*/
		struct pstore_zone_info {
		struct module *owner;

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