mtd, ubi, ubifs: resync with Linux-3.14

resync ubi subsystem with linux:

commit 455c6fdbd219161bd09b1165f11699d6d73de11c
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Mar 30 20:40:15 2014 -0700

    Linux 3.14

A nice side effect of this, is we introduce UBI Fastmap support
to U-Boot.

Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Tom Rini <trini@ti.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Sergey Lapin <slapin@ossfans.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Joerg Krause <jkrause@posteo.de>
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 7d27eda..3c2a7e6 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -7,20 +7,20 @@
  */
 
 /*
- * The UBI Eraseblock Association (EBA) unit.
+ * The UBI Eraseblock Association (EBA) sub-system.
  *
- * This unit is responsible for I/O to/from logical eraseblock.
+ * This sub-system is responsible for I/O to/from logical eraseblock.
  *
  * Although in this implementation the EBA table is fully kept and managed in
  * RAM, which assumes poor scalability, it might be (partially) maintained on
  * flash in future implementations.
  *
- * The EBA unit implements per-logical eraseblock locking. Before accessing a
- * logical eraseblock it is locked for reading or writing. The per-logical
- * eraseblock locking is implemented by means of the lock tree. The lock tree
- * is an RB-tree which refers all the currently locked logical eraseblocks. The
- * lock tree elements are &struct ubi_ltree_entry objects. They are indexed by
- * (@vol_id, @lnum) pairs.
+ * The EBA sub-system implements per-logical eraseblock locking. Before
+ * accessing a logical eraseblock it is locked for reading or writing. The
+ * per-logical eraseblock locking is implemented by means of the lock tree. The
+ * lock tree is an RB-tree which refers all the currently locked logical
+ * eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects.
+ * They are indexed by (@vol_id, @lnum) pairs.
  *
  * EBA also maintains the global sequence counter which is incremented each
  * time a logical eraseblock is mapped to a physical eraseblock and it is
@@ -29,13 +29,15 @@
  * 64 bits is enough to never overflow.
  */
 
-#ifdef UBI_LINUX
+#define __UBOOT__
+#ifndef __UBOOT__
 #include <linux/slab.h>
 #include <linux/crc32.h>
-#include <linux/err.h>
+#else
+#include <ubi_uboot.h>
 #endif
 
-#include <ubi_uboot.h>
+#include <linux/err.h>
 #include "ubi.h"
 
 /* Number of physical eraseblocks reserved for atomic LEB change operation */
@@ -49,7 +51,7 @@
  * global sequence counter value. It also increases the global sequence
  * counter.
  */
-static unsigned long long next_sqnum(struct ubi_device *ubi)
+unsigned long long ubi_next_sqnum(struct ubi_device *ubi)
 {
 	unsigned long long sqnum;
 
@@ -181,9 +183,7 @@
 	le->users += 1;
 	spin_unlock(&ubi->ltree_lock);
 
-	if (le_free)
-		kfree(le_free);
-
+	kfree(le_free);
 	return le;
 }
 
@@ -215,22 +215,18 @@
  */
 static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 {
-	int _free = 0;
 	struct ubi_ltree_entry *le;
 
 	spin_lock(&ubi->ltree_lock);
 	le = ltree_lookup(ubi, vol_id, lnum);
 	le->users -= 1;
 	ubi_assert(le->users >= 0);
+	up_read(&le->mutex);
 	if (le->users == 0) {
 		rb_erase(&le->rb, &ubi->ltree);
-		_free = 1;
+		kfree(le);
 	}
 	spin_unlock(&ubi->ltree_lock);
-
-	up_read(&le->mutex);
-	if (_free)
-		kfree(le);
 }
 
 /**
@@ -266,7 +262,6 @@
  */
 static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
 {
-	int _free;
 	struct ubi_ltree_entry *le;
 
 	le = ltree_add_entry(ubi, vol_id, lnum);
@@ -281,12 +276,9 @@
 	ubi_assert(le->users >= 0);
 	if (le->users == 0) {
 		rb_erase(&le->rb, &ubi->ltree);
-		_free = 1;
-	} else
-		_free = 0;
-	spin_unlock(&ubi->ltree_lock);
-	if (_free)
 		kfree(le);
+	}
+	spin_unlock(&ubi->ltree_lock);
 
 	return 1;
 }
@@ -299,23 +291,18 @@
  */
 static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
 {
-	int _free;
 	struct ubi_ltree_entry *le;
 
 	spin_lock(&ubi->ltree_lock);
 	le = ltree_lookup(ubi, vol_id, lnum);
 	le->users -= 1;
 	ubi_assert(le->users >= 0);
+	up_write(&le->mutex);
 	if (le->users == 0) {
 		rb_erase(&le->rb, &ubi->ltree);
-		_free = 1;
-	} else
-		_free = 0;
-	spin_unlock(&ubi->ltree_lock);
-
-	up_write(&le->mutex);
-	if (_free)
 		kfree(le);
+	}
+	spin_unlock(&ubi->ltree_lock);
 }
 
 /**
@@ -347,8 +334,10 @@
 
 	dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
 
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
-	err = ubi_wl_put_peb(ubi, pnum, 0);
+	up_read(&ubi->fm_sem);
+	err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 0);
 
 out_unlock:
 	leb_write_unlock(ubi, vol_id, lnum);
@@ -425,9 +414,10 @@
 				 * may try to recover data. FIXME: but this is
 				 * not implemented.
 				 */
-				if (err == UBI_IO_BAD_VID_HDR) {
-					ubi_warn("bad VID header at PEB %d, LEB"
-						 "%d:%d", pnum, vol_id, lnum);
+				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, lnum);
 					err = -EBADMSG;
 				} else
 					ubi_ro_mode(ubi);
@@ -508,16 +498,12 @@
 	struct ubi_vid_hdr *vid_hdr;
 
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
-	if (!vid_hdr) {
+	if (!vid_hdr)
 		return -ENOMEM;
-	}
-
-	mutex_lock(&ubi->buf_mutex);
 
 retry:
-	new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
+	new_pnum = ubi_wl_get_peb(ubi);
 	if (new_pnum < 0) {
-		mutex_unlock(&ubi->buf_mutex);
 		ubi_free_vid_hdr(ubi, vid_hdr);
 		return new_pnum;
 	}
@@ -531,39 +517,45 @@
 		goto out_put;
 	}
 
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 	err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
 	if (err)
 		goto write_error;
 
 	data_size = offset + len;
-	memset(ubi->peb_buf1 + offset, 0xFF, len);
+	mutex_lock(&ubi->buf_mutex);
+	memset(ubi->peb_buf + offset, 0xFF, len);
 
 	/* Read everything before the area where the write failure happened */
 	if (offset > 0) {
-		err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
+		err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, offset);
 		if (err && err != UBI_IO_BITFLIPS)
-			goto out_put;
+			goto out_unlock;
 	}
 
-	memcpy(ubi->peb_buf1 + offset, buf, len);
+	memcpy(ubi->peb_buf + offset, buf, len);
 
-	err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
-	if (err)
+	err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size);
+	if (err) {
+		mutex_unlock(&ubi->buf_mutex);
 		goto write_error;
+	}
 
 	mutex_unlock(&ubi->buf_mutex);
 	ubi_free_vid_hdr(ubi, vid_hdr);
 
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = new_pnum;
-	ubi_wl_put_peb(ubi, pnum, 1);
+	up_read(&ubi->fm_sem);
+	ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
 
 	ubi_msg("data was successfully recovered");
 	return 0;
 
-out_put:
+out_unlock:
 	mutex_unlock(&ubi->buf_mutex);
-	ubi_wl_put_peb(ubi, new_pnum, 1);
+out_put:
+	ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1);
 	ubi_free_vid_hdr(ubi, vid_hdr);
 	return err;
 
@@ -573,9 +565,8 @@
 	 * get another one.
 	 */
 	ubi_warn("failed to write to PEB %d", new_pnum);
-	ubi_wl_put_peb(ubi, new_pnum, 1);
+	ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1);
 	if (++tries > UBI_IO_RETRIES) {
-		mutex_unlock(&ubi->buf_mutex);
 		ubi_free_vid_hdr(ubi, vid_hdr);
 		return err;
 	}
@@ -591,7 +582,6 @@
  * @buf: the data to write
  * @offset: offset within the logical eraseblock where to write
  * @len: how many bytes to write
- * @dtype: data type
  *
  * This function writes data to logical eraseblock @lnum of a dynamic volume
  * @vol. Returns zero in case of success and a negative error code in case
@@ -599,7 +589,7 @@
  * written to the flash media, but may be some garbage.
  */
 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
-		      const void *buf, int offset, int len, int dtype)
+		      const void *buf, int offset, int len)
 {
 	int err, pnum, tries = 0, vol_id = vol->vol_id;
 	struct ubi_vid_hdr *vid_hdr;
@@ -640,14 +630,14 @@
 	}
 
 	vid_hdr->vol_type = UBI_VID_DYNAMIC;
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 	vid_hdr->vol_id = cpu_to_be32(vol_id);
 	vid_hdr->lnum = cpu_to_be32(lnum);
 	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
 	vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
 
 retry:
-	pnum = ubi_wl_get_peb(ubi, dtype);
+	pnum = ubi_wl_get_peb(ubi);
 	if (pnum < 0) {
 		ubi_free_vid_hdr(ubi, vid_hdr);
 		leb_write_unlock(ubi, vol_id, lnum);
@@ -667,14 +657,15 @@
 	if (len) {
 		err = ubi_io_write_data(ubi, buf, pnum, offset, len);
 		if (err) {
-			ubi_warn("failed to write %d bytes at offset %d of "
-				 "LEB %d:%d, PEB %d", len, offset, vol_id,
-				 lnum, pnum);
+			ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, PEB %d",
+				 len, offset, vol_id, lnum, pnum);
 			goto write_error;
 		}
 	}
 
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = pnum;
+	up_read(&ubi->fm_sem);
 
 	leb_write_unlock(ubi, vol_id, lnum);
 	ubi_free_vid_hdr(ubi, vid_hdr);
@@ -693,7 +684,7 @@
 	 * eraseblock, so just put it and request a new one. We assume that if
 	 * this physical eraseblock went bad, the erase code will handle that.
 	 */
-	err = ubi_wl_put_peb(ubi, pnum, 1);
+	err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
 	if (err || ++tries > UBI_IO_RETRIES) {
 		ubi_ro_mode(ubi);
 		leb_write_unlock(ubi, vol_id, lnum);
@@ -701,7 +692,7 @@
 		return err;
 	}
 
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 	ubi_msg("try another PEB");
 	goto retry;
 }
@@ -713,7 +704,6 @@
  * @lnum: logical eraseblock number
  * @buf: data to write
  * @len: how many bytes to write
- * @dtype: data type
  * @used_ebs: how many logical eraseblocks will this volume contain
  *
  * This function writes data to logical eraseblock @lnum of static volume
@@ -725,13 +715,12 @@
  * to the real data size, although the @buf buffer has to contain the
  * alignment. In all other cases, @len has to be aligned.
  *
- * It is prohibited to write more then once to logical eraseblocks of static
+ * It is prohibited to write more than once to logical eraseblocks of static
  * volumes. This function returns zero in case of success and a negative error
  * code in case of failure.
  */
 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
-			 int lnum, const void *buf, int len, int dtype,
-			 int used_ebs)
+			 int lnum, const void *buf, int len, int used_ebs)
 {
 	int err, pnum, tries = 0, data_size = len, vol_id = vol->vol_id;
 	struct ubi_vid_hdr *vid_hdr;
@@ -756,7 +745,7 @@
 		return err;
 	}
 
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 	vid_hdr->vol_id = cpu_to_be32(vol_id);
 	vid_hdr->lnum = cpu_to_be32(lnum);
 	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
@@ -769,7 +758,7 @@
 	vid_hdr->data_crc = cpu_to_be32(crc);
 
 retry:
-	pnum = ubi_wl_get_peb(ubi, dtype);
+	pnum = ubi_wl_get_peb(ubi);
 	if (pnum < 0) {
 		ubi_free_vid_hdr(ubi, vid_hdr);
 		leb_write_unlock(ubi, vol_id, lnum);
@@ -794,7 +783,9 @@
 	}
 
 	ubi_assert(vol->eba_tbl[lnum] < 0);
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = pnum;
+	up_read(&ubi->fm_sem);
 
 	leb_write_unlock(ubi, vol_id, lnum);
 	ubi_free_vid_hdr(ubi, vid_hdr);
@@ -813,7 +804,7 @@
 		return err;
 	}
 
-	err = ubi_wl_put_peb(ubi, pnum, 1);
+	err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
 	if (err || ++tries > UBI_IO_RETRIES) {
 		ubi_ro_mode(ubi);
 		leb_write_unlock(ubi, vol_id, lnum);
@@ -821,7 +812,7 @@
 		return err;
 	}
 
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 	ubi_msg("try another PEB");
 	goto retry;
 }
@@ -833,7 +824,6 @@
  * @lnum: logical eraseblock number
  * @buf: data to write
  * @len: how many bytes to write
- * @dtype: data type
  *
  * This function changes the contents of a logical eraseblock atomically. @buf
  * has to contain new logical eraseblock data, and @len - the length of the
@@ -845,7 +835,7 @@
  * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
  */
 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
-			      int lnum, const void *buf, int len, int dtype)
+			      int lnum, const void *buf, int len)
 {
 	int err, pnum, tries = 0, vol_id = vol->vol_id;
 	struct ubi_vid_hdr *vid_hdr;
@@ -862,7 +852,7 @@
 		err = ubi_eba_unmap_leb(ubi, vol, lnum);
 		if (err)
 			return err;
-		return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
+		return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0);
 	}
 
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
@@ -874,7 +864,7 @@
 	if (err)
 		goto out_mutex;
 
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 	vid_hdr->vol_id = cpu_to_be32(vol_id);
 	vid_hdr->lnum = cpu_to_be32(lnum);
 	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
@@ -887,7 +877,7 @@
 	vid_hdr->data_crc = cpu_to_be32(crc);
 
 retry:
-	pnum = ubi_wl_get_peb(ubi, dtype);
+	pnum = ubi_wl_get_peb(ubi);
 	if (pnum < 0) {
 		err = pnum;
 		goto out_leb_unlock;
@@ -911,12 +901,14 @@
 	}
 
 	if (vol->eba_tbl[lnum] >= 0) {
-		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1);
+		err = ubi_wl_put_peb(ubi, vol_id, lnum, vol->eba_tbl[lnum], 0);
 		if (err)
 			goto out_leb_unlock;
 	}
 
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = pnum;
+	up_read(&ubi->fm_sem);
 
 out_leb_unlock:
 	leb_write_unlock(ubi, vol_id, lnum);
@@ -936,18 +928,45 @@
 		goto out_leb_unlock;
 	}
 
-	err = ubi_wl_put_peb(ubi, pnum, 1);
+	err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
 	if (err || ++tries > UBI_IO_RETRIES) {
 		ubi_ro_mode(ubi);
 		goto out_leb_unlock;
 	}
 
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 	ubi_msg("try another PEB");
 	goto retry;
 }
 
 /**
+ * is_error_sane - check whether a read error is sane.
+ * @err: code of the error happened during reading
+ *
+ * This is a helper function for 'ubi_eba_copy_leb()' which is called when we
+ * cannot read data from the target PEB (an error @err happened). If the error
+ * code is sane, then we treat this error as non-fatal. Otherwise the error is
+ * fatal and UBI will be switched to R/O mode later.
+ *
+ * The idea is that we try not to switch to R/O mode if the read error is
+ * something which suggests there was a real read problem. E.g., %-EIO. Or a
+ * memory allocation failed (-%ENOMEM). Otherwise, it is safer to switch to R/O
+ * mode, simply because we do not know what happened at the MTD level, and we
+ * cannot handle this. E.g., the underlying driver may have become crazy, and
+ * it is safer to switch to R/O mode to preserve the data.
+ *
+ * And bear in mind, this is about reading from the target PEB, i.e. the PEB
+ * which we have just written.
+ */
+static int is_error_sane(int err)
+{
+	if (err == -EIO || err == -ENOMEM || err == UBI_IO_BAD_HDR ||
+	    err == UBI_IO_BAD_HDR_EBADMSG || err == -ETIMEDOUT)
+		return 0;
+	return 1;
+}
+
+/**
  * ubi_eba_copy_leb - copy logical eraseblock.
  * @ubi: UBI device description object
  * @from: physical eraseblock number from where to copy
@@ -957,10 +976,9 @@
  * This function copies logical eraseblock from physical eraseblock @from to
  * physical eraseblock @to. The @vid_hdr buffer may be changed by this
  * function. Returns:
- *   o %0  in case of success;
- *   o %1 if the operation was canceled and should be tried later (e.g.,
- *     because a bit-flip was detected at the target PEB);
- *   o %2 if the volume is being deleted and this LEB should not be moved.
+ *   o %0 in case of success;
+ *   o %MOVE_CANCEL_RACE, %MOVE_TARGET_WR_ERR, %MOVE_TARGET_BITFLIPS, etc;
+ *   o a negative error code in case of failure.
  */
 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 		     struct ubi_vid_hdr *vid_hdr)
@@ -972,7 +990,7 @@
 	vol_id = be32_to_cpu(vid_hdr->vol_id);
 	lnum = be32_to_cpu(vid_hdr->lnum);
 
-	dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to);
+	dbg_wl("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to);
 
 	if (vid_hdr->vol_type == UBI_VID_STATIC) {
 		data_size = be32_to_cpu(vid_hdr->data_size);
@@ -986,17 +1004,16 @@
 	/*
 	 * Note, we may race with volume deletion, which means that the volume
 	 * this logical eraseblock belongs to might be being deleted. Since the
-	 * volume deletion unmaps all the volume's logical eraseblocks, it will
+	 * volume deletion un-maps all the volume's logical eraseblocks, it will
 	 * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
 	 */
 	vol = ubi->volumes[idx];
+	spin_unlock(&ubi->volumes_lock);
 	if (!vol) {
 		/* No need to do further work, cancel */
-		dbg_eba("volume %d is being removed, cancel", vol_id);
-		spin_unlock(&ubi->volumes_lock);
-		return 2;
+		dbg_wl("volume %d is being removed, cancel", vol_id);
+		return MOVE_CANCEL_RACE;
 	}
-	spin_unlock(&ubi->volumes_lock);
 
 	/*
 	 * We do not want anybody to write to this logical eraseblock while we
@@ -1008,12 +1025,15 @@
 	 * (@from). This task locks the LEB and goes sleep in the
 	 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
 	 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
-	 * LEB is already locked, we just do not move it and return %1.
+	 * LEB is already locked, we just do not move it and return
+	 * %MOVE_RETRY. Note, we do not return %MOVE_CANCEL_RACE here because
+	 * we do not know the reasons of the contention - it may be just a
+	 * normal I/O on this LEB, so we want to re-try.
 	 */
 	err = leb_write_trylock(ubi, vol_id, lnum);
 	if (err) {
-		dbg_eba("contention on LEB %d:%d, cancel", vol_id, lnum);
-		return err;
+		dbg_wl("contention on LEB %d:%d, cancel", vol_id, lnum);
+		return MOVE_RETRY;
 	}
 
 	/*
@@ -1022,30 +1042,30 @@
 	 * cancel it.
 	 */
 	if (vol->eba_tbl[lnum] != from) {
-		dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
-			"PEB %d, cancel", vol_id, lnum, from,
-			vol->eba_tbl[lnum]);
-		err = 1;
+		dbg_wl("LEB %d:%d is no longer mapped to PEB %d, mapped to PEB %d, cancel",
+		       vol_id, lnum, from, vol->eba_tbl[lnum]);
+		err = MOVE_CANCEL_RACE;
 		goto out_unlock_leb;
 	}
 
 	/*
-	 * OK, now the LEB is locked and we can safely start moving iy. Since
-	 * this function utilizes thie @ubi->peb1_buf buffer which is shared
-	 * with some other functions, so lock the buffer by taking the
+	 * OK, now the LEB is locked and we can safely start moving it. Since
+	 * this function utilizes the @ubi->peb_buf buffer which is shared
+	 * with some other functions - we lock the buffer by taking the
 	 * @ubi->buf_mutex.
 	 */
 	mutex_lock(&ubi->buf_mutex);
-	dbg_eba("read %d bytes of data", aldata_size);
-	err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size);
+	dbg_wl("read %d bytes of data", aldata_size);
+	err = ubi_io_read_data(ubi, ubi->peb_buf, from, 0, aldata_size);
 	if (err && err != UBI_IO_BITFLIPS) {
 		ubi_warn("error %d while reading data from PEB %d",
 			 err, from);
+		err = MOVE_SOURCE_RD_ERR;
 		goto out_unlock_buf;
 	}
 
 	/*
-	 * Now we have got to calculate how much data we have to to copy. In
+	 * Now we have got to calculate how much data we have to copy. In
 	 * case of a static volume it is fairly easy - the VID header contains
 	 * the data size. In case of a dynamic volume it is more difficult - we
 	 * have to read the contents, cut 0xFF bytes from the end and copy only
@@ -1056,14 +1076,14 @@
 	 */
 	if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
 		aldata_size = data_size =
-			ubi_calc_data_len(ubi, ubi->peb_buf1, data_size);
+			ubi_calc_data_len(ubi, ubi->peb_buf, data_size);
 
 	cond_resched();
-	crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size);
+	crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size);
 	cond_resched();
 
 	/*
-	 * It may turn out to me that the whole @from physical eraseblock
+	 * It may turn out to be that the whole @from physical eraseblock
 	 * contains only 0xFF bytes. Then we have to only write the VID header
 	 * and do not write any data. This also means we should not set
 	 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
@@ -1073,28 +1093,37 @@
 		vid_hdr->data_size = cpu_to_be32(data_size);
 		vid_hdr->data_crc = cpu_to_be32(crc);
 	}
-	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
 
 	err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
-	if (err)
+	if (err) {
+		if (err == -EIO)
+			err = MOVE_TARGET_WR_ERR;
 		goto out_unlock_buf;
+	}
 
 	cond_resched();
 
 	/* Read the VID header back and check if it was written correctly */
 	err = ubi_io_read_vid_hdr(ubi, to, vid_hdr, 1);
 	if (err) {
-		if (err != UBI_IO_BITFLIPS)
-			ubi_warn("cannot read VID header back from PEB %d", to);
-		else
-			err = 1;
+		if (err != UBI_IO_BITFLIPS) {
+			ubi_warn("error %d while reading VID header back from PEB %d",
+				 err, to);
+			if (is_error_sane(err))
+				err = MOVE_TARGET_RD_ERR;
+		} else
+			err = MOVE_TARGET_BITFLIPS;
 		goto out_unlock_buf;
 	}
 
 	if (data_size > 0) {
-		err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
-		if (err)
+		err = ubi_io_write_data(ubi, ubi->peb_buf, to, 0, aldata_size);
+		if (err) {
+			if (err == -EIO)
+				err = MOVE_TARGET_WR_ERR;
 			goto out_unlock_buf;
+		}
 
 		cond_resched();
 
@@ -1102,28 +1131,33 @@
 		 * We've written the data and are going to read it back to make
 		 * sure it was written correctly.
 		 */
-
-		err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size);
+		memset(ubi->peb_buf, 0xFF, aldata_size);
+		err = ubi_io_read_data(ubi, ubi->peb_buf, to, 0, aldata_size);
 		if (err) {
-			if (err != UBI_IO_BITFLIPS)
-				ubi_warn("cannot read data back from PEB %d",
-					 to);
-			else
-				err = 1;
+			if (err != UBI_IO_BITFLIPS) {
+				ubi_warn("error %d while reading data back from PEB %d",
+					 err, to);
+				if (is_error_sane(err))
+					err = MOVE_TARGET_RD_ERR;
+			} else
+				err = MOVE_TARGET_BITFLIPS;
 			goto out_unlock_buf;
 		}
 
 		cond_resched();
 
-		if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
-			ubi_warn("read data back from PEB %d - it is different",
+		if (crc != crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size)) {
+			ubi_warn("read data back from PEB %d and it is different",
 				 to);
+			err = -EINVAL;
 			goto out_unlock_buf;
 		}
 	}
 
 	ubi_assert(vol->eba_tbl[lnum] == from);
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = to;
+	up_read(&ubi->fm_sem);
 
 out_unlock_buf:
 	mutex_unlock(&ubi->buf_mutex);
@@ -1133,28 +1167,165 @@
 }
 
 /**
- * ubi_eba_init_scan - initialize the EBA unit using scanning information.
+ * print_rsvd_warning - warn about not having enough reserved PEBs.
  * @ubi: UBI device description object
- * @si: scanning information
+ *
+ * This is a helper function for 'ubi_eba_init()' which is called when UBI
+ * cannot reserve enough PEBs for bad block handling. This function makes a
+ * decision whether we have to print a warning or not. The algorithm is as
+ * follows:
+ *   o if this is a new UBI image, then just print the warning
+ *   o if this is an UBI image which has already been used for some time, print
+ *     a warning only if we can reserve less than 10% of the expected amount of
+ *     the reserved PEB.
+ *
+ * The idea is that when UBI is used, PEBs become bad, and the reserved pool
+ * of PEBs becomes smaller, which is normal and we do not want to scare users
+ * with a warning every time they attach the MTD device. This was an issue
+ * reported by real users.
+ */
+static void print_rsvd_warning(struct ubi_device *ubi,
+			       struct ubi_attach_info *ai)
+{
+	/*
+	 * The 1 << 18 (256KiB) number is picked randomly, just a reasonably
+	 * large number to distinguish between newly flashed and used images.
+	 */
+	if (ai->max_sqnum > (1 << 18)) {
+		int min = ubi->beb_rsvd_level / 10;
+
+		if (!min)
+			min = 1;
+		if (ubi->beb_rsvd_pebs > min)
+			return;
+	}
+
+	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);
+}
+
+/**
+ * self_check_eba - run a self check on the EBA table constructed by fastmap.
+ * @ubi: UBI device description object
+ * @ai_fastmap: UBI attach info object created by fastmap
+ * @ai_scan: UBI attach info object created by scanning
+ *
+ * Returns < 0 in case of an internal error, 0 otherwise.
+ * If a bad EBA table entry was found it will be printed out and
+ * ubi_assert() triggers.
+ */
+int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
+		   struct ubi_attach_info *ai_scan)
+{
+	int i, j, num_volumes, ret = 0;
+	int **scan_eba, **fm_eba;
+	struct ubi_ainf_volume *av;
+	struct ubi_volume *vol;
+	struct ubi_ainf_peb *aeb;
+	struct rb_node *rb;
+
+	num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
+
+	scan_eba = kmalloc(sizeof(*scan_eba) * num_volumes, GFP_KERNEL);
+	if (!scan_eba)
+		return -ENOMEM;
+
+	fm_eba = kmalloc(sizeof(*fm_eba) * num_volumes, GFP_KERNEL);
+	if (!fm_eba) {
+		kfree(scan_eba);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < num_volumes; i++) {
+		vol = ubi->volumes[i];
+		if (!vol)
+			continue;
+
+		scan_eba[i] = kmalloc(vol->reserved_pebs * sizeof(**scan_eba),
+				      GFP_KERNEL);
+		if (!scan_eba[i]) {
+			ret = -ENOMEM;
+			goto out_free;
+		}
+
+		fm_eba[i] = kmalloc(vol->reserved_pebs * sizeof(**fm_eba),
+				    GFP_KERNEL);
+		if (!fm_eba[i]) {
+			ret = -ENOMEM;
+			goto out_free;
+		}
+
+		for (j = 0; j < vol->reserved_pebs; j++)
+			scan_eba[i][j] = fm_eba[i][j] = UBI_LEB_UNMAPPED;
+
+		av = ubi_find_av(ai_scan, idx2vol_id(ubi, i));
+		if (!av)
+			continue;
+
+		ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb)
+			scan_eba[i][aeb->lnum] = aeb->pnum;
+
+		av = ubi_find_av(ai_fastmap, idx2vol_id(ubi, i));
+		if (!av)
+			continue;
+
+		ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb)
+			fm_eba[i][aeb->lnum] = aeb->pnum;
+
+		for (j = 0; j < vol->reserved_pebs; j++) {
+			if (scan_eba[i][j] != fm_eba[i][j]) {
+				if (scan_eba[i][j] == UBI_LEB_UNMAPPED ||
+					fm_eba[i][j] == UBI_LEB_UNMAPPED)
+					continue;
+
+				ubi_err("LEB:%i:%i is PEB:%i instead of %i!",
+					vol->vol_id, i, fm_eba[i][j],
+					scan_eba[i][j]);
+				ubi_assert(0);
+			}
+		}
+	}
+
+out_free:
+	for (i = 0; i < num_volumes; i++) {
+		if (!ubi->volumes[i])
+			continue;
+
+		kfree(scan_eba[i]);
+		kfree(fm_eba[i]);
+	}
+
+	kfree(scan_eba);
+	kfree(fm_eba);
+	return ret;
+}
+
+/**
+ * ubi_eba_init - initialize the EBA sub-system using attaching information.
+ * @ubi: UBI device description object
+ * @ai: attaching information
  *
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
-int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
+int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 {
 	int i, j, err, num_volumes;
-	struct ubi_scan_volume *sv;
+	struct ubi_ainf_volume *av;
 	struct ubi_volume *vol;
-	struct ubi_scan_leb *seb;
+	struct ubi_ainf_peb *aeb;
 	struct rb_node *rb;
 
-	dbg_eba("initialize EBA unit");
+	dbg_eba("initialize EBA sub-system");
 
 	spin_lock_init(&ubi->ltree_lock);
 	mutex_init(&ubi->alc_mutex);
 	ubi->ltree = RB_ROOT;
 
-	ubi->global_sqnum = si->max_sqnum + 1;
+	ubi->global_sqnum = ai->max_sqnum + 1;
 	num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
 
 	for (i = 0; i < num_volumes; i++) {
@@ -1174,24 +1345,27 @@
 		for (j = 0; j < vol->reserved_pebs; j++)
 			vol->eba_tbl[j] = UBI_LEB_UNMAPPED;
 
-		sv = ubi_scan_find_sv(si, idx2vol_id(ubi, i));
-		if (!sv)
+		av = ubi_find_av(ai, idx2vol_id(ubi, i));
+		if (!av)
 			continue;
 
-		ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
-			if (seb->lnum >= vol->reserved_pebs)
+		ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) {
+			if (aeb->lnum >= vol->reserved_pebs)
 				/*
 				 * This may happen in case of an unclean reboot
 				 * during re-size.
 				 */
-				ubi_scan_move_to_list(sv, seb, &si->erase);
-			vol->eba_tbl[seb->lnum] = seb->pnum;
+				ubi_move_aeb_to_list(av, aeb, &ai->erase);
+			vol->eba_tbl[aeb->lnum] = aeb->pnum;
 		}
 	}
 
 	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;
 	}
@@ -1204,9 +1378,7 @@
 		if (ubi->avail_pebs < ubi->beb_rsvd_level) {
 			/* No enough free physical eraseblocks */
 			ubi->beb_rsvd_pebs = ubi->avail_pebs;
-			ubi_warn("cannot reserve enough PEBs for bad PEB "
-				 "handling, reserved %d, need %d",
-				 ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
+			print_rsvd_warning(ubi, ai);
 		} else
 			ubi->beb_rsvd_pebs = ubi->beb_rsvd_level;
 
@@ -1214,7 +1386,7 @@
 		ubi->rsvd_pebs  += ubi->beb_rsvd_pebs;
 	}
 
-	dbg_eba("EBA unit is initialized");
+	dbg_eba("EBA sub-system is initialized");
 	return 0;
 
 out_free:
@@ -1222,23 +1394,7 @@
 		if (!ubi->volumes[i])
 			continue;
 		kfree(ubi->volumes[i]->eba_tbl);
+		ubi->volumes[i]->eba_tbl = NULL;
 	}
 	return err;
 }
-
-/**
- * ubi_eba_close - close EBA unit.
- * @ubi: UBI device description object
- */
-void ubi_eba_close(const struct ubi_device *ubi)
-{
-	int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
-
-	dbg_eba("close EBA unit");
-
-	for (i = 0; i < num_volumes; i++) {
-		if (!ubi->volumes[i])
-			continue;
-		kfree(ubi->volumes[i]->eba_tbl);
-	}
-}