Merge branch 'linux-next' of git://git.infradead.org/ubi-2.6

* 'linux-next' of git://git.infradead.org/ubi-2.6:
  UBI: tighten the corrupted PEB criteria
  UBI: fix check_data_ff return code
  UBI: remember copy_flag while scanning
  UBI: preserve corrupted PEBs
  UBI: add truly corrupted PEBs to corrupted list
  UBI: introduce debugging helper function
  UBI: make check_pattern function non-static
  UBI: do not put eraseblocks to the corrupted list unnecessarily
  UBI: separate out corrupted list
  UBI: change cascade of ifs to switch statements
  UBI: rename a local variable
  UBI: handle bit-flips when no header found
  UBI: remove duplicate IO error codes
  UBI: rename IO error code
  UBI: fix small 80 characters limit style issue
  UBI: cleanup and simplify Kconfig

drivers/mtd/ubi/Kconfig

-menu "UBI - Unsorted block images"
-	depends on MTD
-
-config MTD_UBI
-	tristate "Enable UBI"
-	depends on MTD
+menuconfig MTD_UBI
+	tristate "Enable UBI - Unsorted block images"
 	select CRC32
 	help
 	  UBI is a software layer above MTD layer which admits of LVM-like
@@ -12,11 +8,12 @@ config MTD_UBI
 	  capabilities. Please, consult the MTD web site for more details
 	  (www.linux-mtd.infradead.org).
 
+if MTD_UBI
+
 config MTD_UBI_WL_THRESHOLD
 	int "UBI wear-leveling threshold"
 	default 4096
 	range 2 65536
-	depends on MTD_UBI
 	help
 	  This parameter defines the maximum difference between the highest
 	  erase counter value and the lowest erase counter value of eraseblocks
@@ -34,7 +31,6 @@ config MTD_UBI_BEB_RESERVE
 	int "Percentage of reserved eraseblocks for bad eraseblocks handling"
 	default 1
 	range 0 25
-	depends on MTD_UBI
 	help
 	  If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI
 	  reserves some amount of physical eraseblocks to handle new bad
@@ -48,8 +44,6 @@ config MTD_UBI_BEB_RESERVE
 
 config MTD_UBI_GLUEBI
 	tristate "MTD devices emulation driver (gluebi)"
-	default n
-	depends on MTD_UBI
 	help
 	   This option enables gluebi - an additional driver which emulates MTD
 	   devices on top of UBI volumes: for each UBI volumes an MTD device is
@@ -59,4 +53,5 @@ config MTD_UBI_GLUEBI
 	   software.
 
 source "drivers/mtd/ubi/Kconfig.debug"
-endmenu
+
+endif # MTD_UBI

drivers/mtd/ubi/Kconfig.debug

 comment "UBI debugging options"
-	depends on MTD_UBI
 
 config MTD_UBI_DEBUG
 	bool "UBI debugging"
 	depends on SYSFS
-	depends on MTD_UBI
 	select DEBUG_FS
 	select KALLSYMS_ALL if KALLSYMS && DEBUG_KERNEL
 	help
 	  This option enables UBI debugging.
 
+if MTD_UBI_DEBUG
+
 config MTD_UBI_DEBUG_MSG
 	bool "UBI debugging messages"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option enables UBI debugging messages.
 
 config MTD_UBI_DEBUG_PARANOID
 	bool "Extra self-checks"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables extra checks in UBI code. Note this slows UBI down
 	  significantly.
 
 config MTD_UBI_DEBUG_DISABLE_BGT
 	bool "Do not enable the UBI background thread"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option switches the background thread off by default. The thread
 	  may be also be enabled/disabled via UBI sysfs.
 
 config MTD_UBI_DEBUG_EMULATE_BITFLIPS
 	bool "Emulate flash bit-flips"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option emulates bit-flips with probability 1/50, which in turn
 	  causes scrubbing. Useful for debugging and stressing UBI.
 
 config MTD_UBI_DEBUG_EMULATE_WRITE_FAILURES
 	bool "Emulate flash write failures"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option emulates write failures with probability 1/100. Useful for
 	  debugging and testing how UBI handlines errors.
 
 config MTD_UBI_DEBUG_EMULATE_ERASE_FAILURES
 	bool "Emulate flash erase failures"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option emulates erase failures with probability 1/100. Useful for
 	  debugging and testing how UBI handlines errors.
 
-menu "Additional UBI debugging messages"
-	depends on MTD_UBI_DEBUG
+comment "Additional UBI debugging messages"
 
 config MTD_UBI_DEBUG_MSG_BLD
 	bool "Additional UBI initialization and build messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables detailed UBI initialization and device build
 	  debugging messages.
 
 config MTD_UBI_DEBUG_MSG_EBA
 	bool "Eraseblock association unit messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables debugging messages from the UBI eraseblock
 	  association unit.
 
 config MTD_UBI_DEBUG_MSG_WL
 	bool "Wear-leveling unit messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables debugging messages from the UBI wear-leveling
 	  unit.
 
 config MTD_UBI_DEBUG_MSG_IO
 	bool "Input/output unit messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables debugging messages from the UBI input/output unit.
 
-endmenu # UBI debugging messages
+endif # MTD_UBI_DEBUG

drivers/mtd/ubi/build.c

@@ -95,8 +95,8 @@ DEFINE_MUTEX(ubi_devices_mutex);
 static DEFINE_SPINLOCK(ubi_devices_lock);
 
 /* "Show" method for files in '/<sysfs>/class/ubi/' */
-static ssize_t ubi_version_show(struct class *class, struct class_attribute *attr,
-				char *buf)
+static ssize_t ubi_version_show(struct class *class,
+				struct class_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%d\n", UBI_VERSION);
 }
@@ -591,6 +591,7 @@ static int attach_by_scanning(struct ubi_device *ubi)
 
 	ubi->bad_peb_count = si->bad_peb_count;
 	ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
+	ubi->corr_peb_count = si->corr_peb_count;
 	ubi->max_ec = si->max_ec;
 	ubi->mean_ec = si->mean_ec;
 	ubi_msg("max. sequence number:       %llu", si->max_sqnum);
@@ -972,6 +973,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
 	ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
 	ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
+	ubi_msg("number of corrupted PEBs:   %d", ubi->corr_peb_count);
 	ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
 	ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
 	ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);

drivers/mtd/ubi/debug.h

@@ -57,6 +57,9 @@ void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type);
 void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req);
 void ubi_dbg_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len);
 
+#define ubi_dbg_print_hex_dump(l, ps, pt, r, g, b, len, a)  \
+		print_hex_dump(l, ps, pt, r, g, b, len, a)
+
 #ifdef CONFIG_MTD_UBI_DEBUG_MSG
 /* General debugging messages */
 #define dbg_gen(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
@@ -172,6 +175,7 @@ static inline int ubi_dbg_is_erase_failure(void)
 #define ubi_dbg_dump_seb(seb, type)      ({})
 #define ubi_dbg_dump_mkvol_req(req)      ({})
 #define ubi_dbg_dump_flash(ubi, pnum, offset, len) ({})
+#define ubi_dbg_print_hex_dump(l, ps, pt, r, g, b, len, a)  ({})
 
 #define UBI_IO_DEBUG               0
 #define DBG_DISABLE_BGT            0

drivers/mtd/ubi/eba.c

@@ -418,7 +418,7 @@ int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 				 * may try to recover data. FIXME: but this is
 				 * not implemented.
 				 */
-				if (err == UBI_IO_BAD_HDR_READ ||
+				if (err == UBI_IO_BAD_HDR_EBADMSG ||
 				    err == UBI_IO_BAD_HDR) {
 					ubi_warn("corrupted VID header at PEB "
 						 "%d, LEB %d:%d", pnum, vol_id,
@@ -963,7 +963,7 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 static int is_error_sane(int err)
 {
 	if (err == -EIO || err == -ENOMEM || err == UBI_IO_BAD_HDR ||
-	    err == UBI_IO_BAD_HDR_READ || err == -ETIMEDOUT)
+	    err == UBI_IO_BAD_HDR_EBADMSG || err == -ETIMEDOUT)
 		return 0;
 	return 1;
 }
@@ -1201,6 +1201,9 @@ static void print_rsvd_warning(struct ubi_device *ubi,
 
 	ubi_warn("cannot reserve enough PEBs for bad PEB handling, reserved %d,"
 		 " need %d", ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
+	if (ubi->corr_peb_count)
+		ubi_warn("%d PEBs are corrupted and not used",
+			ubi->corr_peb_count);
 }
 
 /**
@@ -1263,6 +1266,9 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
 		ubi_err("no enough physical eraseblocks (%d, need %d)",
 			ubi->avail_pebs, EBA_RESERVED_PEBS);
+		if (ubi->corr_peb_count)
+			ubi_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
 		err = -ENOSPC;
 		goto out_free;
 	}

drivers/mtd/ubi/io.c

@@ -376,25 +376,6 @@ static int do_sync_erase(struct ubi_device *ubi, int pnum)
 	return 0;
 }
 
-/**
- * check_pattern - check if buffer contains only a certain byte pattern.
- * @buf: buffer to check
- * @patt: the pattern to check
- * @size: buffer size in bytes
- *
- * This function returns %1 in there are only @patt bytes in @buf, and %0 if
- * something else was also found.
- */
-static int check_pattern(const void *buf, uint8_t patt, int size)
-{
-	int i;
-
-	for (i = 0; i < size; i++)
-		if (((const uint8_t *)buf)[i] != patt)
-			return 0;
-	return 1;
-}
-
 /* Patterns to write to a physical eraseblock when torturing it */
 static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
 
@@ -426,7 +407,7 @@ static int torture_peb(struct ubi_device *ubi, int pnum)
 		if (err)
 			goto out;
 
-		err = check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
+		err = ubi_check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
 		if (err == 0) {
 			ubi_err("erased PEB %d, but a non-0xFF byte found",
 				pnum);
@@ -445,7 +426,8 @@ static int torture_peb(struct ubi_device *ubi, int pnum)
 		if (err)
 			goto out;
 
-		err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size);
+		err = ubi_check_pattern(ubi->peb_buf1, patterns[i],
+					ubi->peb_size);
 		if (err == 0) {
 			ubi_err("pattern %x checking failed for PEB %d",
 				patterns[i], pnum);
@@ -517,7 +499,7 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
 	 * In this case we probably anyway have garbage in this PEB.
 	 */
 	err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
-	if (err1 == UBI_IO_BAD_HDR_READ || err1 == UBI_IO_BAD_HDR)
+	if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR)
 		/*
 		 * The VID header is corrupted, so we can safely erase this
 		 * PEB and not afraid that it will be treated as a valid PEB in
@@ -712,47 +694,47 @@ static int validate_ec_hdr(const struct ubi_device *ubi,
  *   and corrected by the flash driver; this is harmless but may indicate that
  *   this eraseblock may become bad soon (but may be not);
  * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
- * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
+ * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
+ *   a data integrity error (uncorrectable ECC error in case of NAND);
+ * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty)
  * o a negative error code in case of failure.
  */
 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 		       struct ubi_ec_hdr *ec_hdr, int verbose)
 {
-	int err, read_err = 0;
+	int err, read_err;
 	uint32_t crc, magic, hdr_crc;
 
 	dbg_io("read EC header from PEB %d", pnum);
 	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
 
-	err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
-	if (err) {
-		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
-			return err;
+	read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
+	if (read_err) {
+		if (read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG)
+			return read_err;
 
 		/*
 		 * We read all the data, but either a correctable bit-flip
-		 * occurred, or MTD reported about some data integrity error,
-		 * like an ECC error in case of NAND. The former is harmless,
-		 * the later may mean that the read data is corrupted. But we
-		 * have a CRC check-sum and we will detect this. If the EC
-		 * header is still OK, we just report this as there was a
-		 * bit-flip.
+		 * occurred, or MTD reported a data integrity error
+		 * (uncorrectable ECC error in case of NAND). The former is
+		 * harmless, the later may mean that the read data is
+		 * corrupted. But we have a CRC check-sum and we will detect
+		 * this. If the EC header is still OK, we just report this as
+		 * there was a bit-flip, to force scrubbing.
 		 */
-		if (err == -EBADMSG)
-			read_err = UBI_IO_BAD_HDR_READ;
 	}
 
 	magic = be32_to_cpu(ec_hdr->magic);
 	if (magic != UBI_EC_HDR_MAGIC) {
-		if (read_err)
-			return read_err;
+		if (read_err == -EBADMSG)
+			return UBI_IO_BAD_HDR_EBADMSG;
 
 		/*
 		 * The magic field is wrong. Let's check if we have read all
 		 * 0xFF. If yes, this physical eraseblock is assumed to be
 		 * empty.
 		 */
-		if (check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
+		if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
 			/* The physical eraseblock is supposedly empty */
 			if (verbose)
 				ubi_warn("no EC header found at PEB %d, "
@@ -760,7 +742,10 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 			else if (UBI_IO_DEBUG)
 				dbg_msg("no EC header found at PEB %d, "
 					"only 0xFF bytes", pnum);
-			return UBI_IO_PEB_EMPTY;
+			if (!read_err)
+				return UBI_IO_FF;
+			else
+				return UBI_IO_FF_BITFLIPS;
 		}
 
 		/*
@@ -788,7 +773,11 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 		} else if (UBI_IO_DEBUG)
 			dbg_msg("bad EC header CRC at PEB %d, calculated "
 				"%#08x, read %#08x", pnum, crc, hdr_crc);
-		return read_err ?: UBI_IO_BAD_HDR;
+
+		if (!read_err)
+			return UBI_IO_BAD_HDR;
+		else
+			return UBI_IO_BAD_HDR_EBADMSG;
 	}
 
 	/* And of course validate what has just been read from the media */
@@ -975,22 +964,16 @@ static int validate_vid_hdr(const struct ubi_device *ubi,
  *
  * This function reads the volume identifier header from physical eraseblock
  * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
- * volume identifier header. The following codes may be returned:
+ * volume identifier header. The error codes are the same as in
+ * 'ubi_io_read_ec_hdr()'.
  *
- * o %0 if the CRC checksum is correct and the header was successfully read;
- * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
- *   and corrected by the flash driver; this is harmless but may indicate that
- *   this eraseblock may become bad soon;
- * o %UBI_IO_BAD_HDR if the volume identifier header is corrupted (a CRC
- *   error detected);
- * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
- *   header there);
- * o a negative error code in case of failure.
+ * Note, the implementation of this function is also very similar to
+ * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
  */
 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 			struct ubi_vid_hdr *vid_hdr, int verbose)
 {
-	int err, read_err = 0;
+	int err, read_err;
 	uint32_t crc, magic, hdr_crc;
 	void *p;
 
@@ -998,48 +981,29 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);
 
 	p = (char *)vid_hdr - ubi->vid_hdr_shift;
-	err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
+	read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
 			  ubi->vid_hdr_alsize);
-	if (err) {
-		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
-			return err;
-
-		/*
-		 * We read all the data, but either a correctable bit-flip
-		 * occurred, or MTD reported about some data integrity error,
-		 * like an ECC error in case of NAND. The former is harmless,
-		 * the later may mean the read data is corrupted. But we have a
-		 * CRC check-sum and we will identify this. If the VID header is
-		 * still OK, we just report this as there was a bit-flip.
-		 */
-		if (err == -EBADMSG)
-			read_err = UBI_IO_BAD_HDR_READ;
-	}
+	if (read_err && read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG)
+		return read_err;
 
 	magic = be32_to_cpu(vid_hdr->magic);
 	if (magic != UBI_VID_HDR_MAGIC) {
-		if (read_err)
-			return read_err;
+		if (read_err == -EBADMSG)
+			return UBI_IO_BAD_HDR_EBADMSG;
 
-		/*
-		 * If we have read all 0xFF bytes, the VID header probably does
-		 * not exist and the physical eraseblock is assumed to be free.
-		 */
-		if (check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
-			/* The physical eraseblock is supposedly free */
+		if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
 			if (verbose)
 				ubi_warn("no VID header found at PEB %d, "
 					 "only 0xFF bytes", pnum);
 			else if (UBI_IO_DEBUG)
 				dbg_msg("no VID header found at PEB %d, "
 					"only 0xFF bytes", pnum);
-			return UBI_IO_PEB_FREE;
+			if (!read_err)
+				return UBI_IO_FF;
+			else
+				return UBI_IO_FF_BITFLIPS;
 		}
 
-		/*
-		 * This is not a valid VID header, and these are not 0xFF
-		 * bytes. Report that the header is corrupted.
-		 */
 		if (verbose) {
 			ubi_warn("bad magic number at PEB %d: %08x instead of "
 				 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
@@ -1061,20 +1025,18 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 		} else if (UBI_IO_DEBUG)
 			dbg_msg("bad CRC at PEB %d, calculated %#08x, "
 				"read %#08x", pnum, crc, hdr_crc);
-		return read_err ?: UBI_IO_BAD_HDR;
+		if (!read_err)
+			return UBI_IO_BAD_HDR;
+		else
+			return UBI_IO_BAD_HDR_EBADMSG;
 	}
 
-	/* Validate the VID header that we have just read */
 	err = validate_vid_hdr(ubi, vid_hdr);
 	if (err) {
 		ubi_err("validation failed for PEB %d", pnum);
 		return -EINVAL;
 	}
 
-	/*
-	 * If there was a read error (%-EBADMSG), but the header CRC is still
-	 * OK, report about a bit-flip to force scrubbing on this PEB.
-	 */
 	return read_err ? UBI_IO_BITFLIPS : 0;
 }
 
@@ -1383,7 +1345,7 @@ int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
 		goto error;
 	}
 
-	err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
+	err = ubi_check_pattern(ubi->dbg_peb_buf, 0xFF, len);
 	if (err == 0) {
 		ubi_err("flash region at PEB %d:%d, length %d does not "
 			"contain all 0xFF bytes", pnum, offset, len);

drivers/mtd/ubi/misc.c

@@ -103,3 +103,22 @@ void ubi_calculate_reserved(struct ubi_device *ubi)
 	if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
 		ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
 }
+
+/**
+ * ubi_check_pattern - check if buffer contains only a certain byte pattern.
+ * @buf: buffer to check
+ * @patt: the pattern to check
+ * @size: buffer size in bytes
+ *
+ * This function returns %1 in there are only @patt bytes in @buf, and %0 if
+ * something else was also found.
+ */
+int ubi_check_pattern(const void *buf, uint8_t patt, int size)
+{
+	int i;
+
+	for (i = 0; i < size; i++)
+		if (((const uint8_t *)buf)[i] != patt)
+			return 0;
+	return 1;
+}

drivers/mtd/ubi/scan.h

@@ -30,6 +30,7 @@
  * @pnum: physical eraseblock number
  * @lnum: logical eraseblock number
  * @scrub: if this physical eraseblock needs scrubbing
+ * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
  * @sqnum: sequence number
  * @u: unions RB-tree or @list links
  * @u.rb: link in the per-volume RB-tree of &struct ubi_scan_leb objects
@@ -42,7 +43,8 @@ struct ubi_scan_leb {
 	int ec;
 	int pnum;
 	int lnum;
-	int scrub;
+	unsigned int scrub:1;
+	unsigned int copy_flag:1;
 	unsigned long long sqnum;
 	union {
 		struct rb_node rb;
@@ -91,14 +93,13 @@ struct ubi_scan_volume {
  * @erase: list of physical eraseblocks which have to be erased
  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
  *         those belonging to "preserve"-compatible internal volumes)
- * @used_peb_count: count of used PEBs
  * @corr_peb_count: count of PEBs in the @corr list
- * @read_err_count: count of PEBs read with error (%UBI_IO_BAD_HDR_READ was
- *                  returned)
- * @free_peb_count: count of PEBs in the @free list
- * @erase_peb_count: count of PEBs in the @erase list
+ * @empty_peb_count: count of PEBs which are presumably empty (contain only
+ *                   0xFF bytes)
  * @alien_peb_count: count of PEBs in the @alien list
  * @bad_peb_count: count of bad physical eraseblocks
+ * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
+ *                       as bad yet, but which look like bad
  * @vols_found: number of volumes found during scanning
  * @highest_vol_id: highest volume ID
  * @is_empty: flag indicating whether the MTD device is empty or not
@@ -119,13 +120,11 @@ struct ubi_scan_info {
 	struct list_head free;
 	struct list_head erase;
 	struct list_head alien;
-	int used_peb_count;
 	int corr_peb_count;
-	int read_err_count;
-	int free_peb_count;
-	int erase_peb_count;
+	int empty_peb_count;
 	int alien_peb_count;
 	int bad_peb_count;
+	int maybe_bad_peb_count;
 	int vols_found;
 	int highest_vol_id;
 	int is_empty;

drivers/mtd/ubi/ubi.h

@@ -85,21 +85,26 @@
 /*
  * Error codes returned by the I/O sub-system.
  *
- * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
- *                   %0xFF bytes
- * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
- *                  valid erase counter header, and the rest are %0xFF bytes
+ * UBI_IO_FF: the read region of flash contains only 0xFFs
+ * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
+ *                     integrity error reported by the MTD driver
+ *                     (uncorrectable ECC error in case of NAND)
  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
- * UBI_IO_BAD_HDR_READ: the same as %UBI_IO_BAD_HDR, but also there was a read
- * 			error reported by the flash driver
+ * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
+ *                         data integrity error reported by the MTD driver
+ *                         (uncorrectable ECC error in case of NAND)
  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
+ *
+ * Note, it is probably better to have bit-flip and ebadmsg as flags which can
+ * be or'ed with other error code. But this is a big change because there are
+ * may callers, so it does not worth the risk of introducing a bug
  */
 enum {
-	UBI_IO_PEB_EMPTY = 1,
-	UBI_IO_PEB_FREE,
+	UBI_IO_FF = 1,
+	UBI_IO_FF_BITFLIPS,
 	UBI_IO_BAD_HDR,
-	UBI_IO_BAD_HDR_READ,
-	UBI_IO_BITFLIPS
+	UBI_IO_BAD_HDR_EBADMSG,
+	UBI_IO_BITFLIPS,
 };
 
 /*
@@ -356,6 +361,8 @@ struct ubi_wl_entry;
  * @peb_size: physical eraseblock size
  * @bad_peb_count: count of bad physical eraseblocks
  * @good_peb_count: count of good physical eraseblocks
+ * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
+ *                  used by UBI)
  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
  * @min_io_size: minimal input/output unit size of the underlying MTD device
@@ -442,6 +449,7 @@ struct ubi_device {
 	int peb_size;
 	int bad_peb_count;
 	int good_peb_count;
+	int corr_peb_count;
 	int erroneous_peb_count;
 	int max_erroneous;
 	int min_io_size;
@@ -506,6 +514,7 @@ int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
 		      int length);
 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 void ubi_calculate_reserved(struct ubi_device *ubi);
+int ubi_check_pattern(const void *buf, uint8_t patt, int size);
 
 /* eba.c */
 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,

drivers/mtd/ubi/vmt.c

@@ -261,6 +261,9 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 	/* Reserve physical eraseblocks */
 	if (vol->reserved_pebs > ubi->avail_pebs) {
 		dbg_err("not enough PEBs, only %d available", ubi->avail_pebs);
+		if (ubi->corr_peb_count)
+			dbg_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
 		err = -ENOSPC;
 		goto out_unlock;
 	}
@@ -527,6 +530,9 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
 		if (pebs > ubi->avail_pebs) {
 			dbg_err("not enough PEBs: requested %d, available %d",
 				pebs, ubi->avail_pebs);
+			if (ubi->corr_peb_count)
+				dbg_err("%d PEBs are corrupted and not used",
+					ubi->corr_peb_count);
 			spin_unlock(&ubi->volumes_lock);
 			err = -ENOSPC;
 			goto out_free;

drivers/mtd/ubi/vtbl.c

@@ -366,7 +366,7 @@ static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si,
 		 * Probably this physical eraseblock went bad, try to pick
 		 * another one.
 		 */
-		list_add_tail(&new_seb->u.list, &si->corr);
+		list_add(&new_seb->u.list, &si->erase);
 		goto retry;
 	}
 	kfree(new_seb);
@@ -662,9 +662,13 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
 	ubi->vol_count += 1;
 	vol->ubi = ubi;
 
-	if (reserved_pebs > ubi->avail_pebs)
+	if (reserved_pebs > ubi->avail_pebs) {
 		ubi_err("not enough PEBs, required %d, available %d",
 			reserved_pebs, ubi->avail_pebs);
+		if (ubi->corr_peb_count)
+			ubi_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
+	}
 	ubi->rsvd_pebs += reserved_pebs;
 	ubi->avail_pebs -= reserved_pebs;
 
@@ -837,7 +841,7 @@ int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si)
 			return PTR_ERR(ubi->vtbl);
 	}
 
-	ubi->avail_pebs = ubi->good_peb_count;
+	ubi->avail_pebs = ubi->good_peb_count - ubi->corr_peb_count;
 
 	/*
 	 * The layout volume is OK, initialize the corresponding in-RAM data

drivers/mtd/ubi/wl.c

@@ -745,7 +745,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 
 	err = ubi_io_read_vid_hdr(ubi, e1->pnum, vid_hdr, 0);
 	if (err && err != UBI_IO_BITFLIPS) {
-		if (err == UBI_IO_PEB_FREE) {
+		if (err == UBI_IO_FF) {
 			/*
 			 * We are trying to move PEB without a VID header. UBI
 			 * always write VID headers shortly after the PEB was
@@ -759,6 +759,16 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 			dbg_wl("PEB %d has no VID header", e1->pnum);
 			protect = 1;
 			goto out_not_moved;
+		} else if (err == UBI_IO_FF_BITFLIPS) {
+			/*
+			 * The same situation as %UBI_IO_FF, but bit-flips were
+			 * detected. It is better to schedule this PEB for
+			 * scrubbing.
+			 */
+			dbg_wl("PEB %d has no VID header but has bit-flips",
+			       e1->pnum);
+			scrubbing = 1;
+			goto out_not_moved;
 		}
 
 		ubi_err("error %d while reading VID header from PEB %d",
@@ -1468,22 +1478,6 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 		ubi->lookuptbl[e->pnum] = e;
 	}
 
-	list_for_each_entry(seb, &si->corr, u.list) {
-		cond_resched();
-
-		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
-		if (!e)
-			goto out_free;
-
-		e->pnum = seb->pnum;
-		e->ec = seb->ec;
-		ubi->lookuptbl[e->pnum] = e;
-		if (schedule_erase(ubi, e, 0)) {
-			kmem_cache_free(ubi_wl_entry_slab, e);
-			goto out_free;
-		}
-	}
-
 	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
 			cond_resched();
@@ -1510,6 +1504,9 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 	if (ubi->avail_pebs < WL_RESERVED_PEBS) {
 		ubi_err("no enough physical eraseblocks (%d, need %d)",
 			ubi->avail_pebs, WL_RESERVED_PEBS);
+		if (ubi->corr_peb_count)
+			ubi_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
 		goto out_free;
 	}
 	ubi->avail_pebs -= WL_RESERVED_PEBS;