Merge tag 'upstream-3.7-rc1-fastmap' of git://git.infradead.org/linux-ubi

Pull UBI fastmap changes from Artem Bityutskiy:
 "This pull request contains the UBI fastmap support implemented by
  Richard Weinberger from Linutronix.  Fastmap is designed to address
  UBI's slow scanning issues.  Namely, it introduces a new on-flash
  data-structure called "fastmap", which stores the information about
  logical<->physical eraseblocks mappings.  So now to get this
  information just read the fastmap, instead of doing full scan.  More
  information here can be found in Richard's announcement in LKML
  (Subject: UBI: Fastmap request for inclusion (v19)):

     http://thread.gmane.org/gmane.linux.kernel/1364922/focus=1369109

  One thing I want to explicitly say is that fastmap did not have large
  enough linux-next exposure.  It is partially my fault - I did not
  respond quickly enough.  I _really_ apologize for this.  But it had
  good testing and disabled by default, so I do not expect that we'll
  break anything.

  Fastmap is declared as experimental so far, and it is off by default.
  We did declare that the on-flash format may be changed.  The reason
  for this is that no one used it in real production so far, so there is
  a high risk that something is missing.  Besides, we do not have
  user-space tools supporting fastmap so far.

  Nevertheless, I suggest we merge this feature.  Many people want UBI's
  scanning bottleneck to be fixed and merging fastmap now should
  accelerate its production use.  The plan is to make it bullet-prove,
  somewhat clean-up, and make it the default for UBI.  I do not know how
  many kernel releases will it take.

  Basically, I what I want to do for fastmap is something like Linus did
  for btrfs few years ago."

* tag 'upstream-3.7-rc1-fastmap' of git://git.infradead.org/linux-ubi:
  UBI: Wire-up fastmap
  UBI: Add fastmap core
  UBI: Add fastmap support to the WL sub-system
  UBI: Add fastmap stuff to attach.c
  UBI: Wire-up ->fm_sem
  UBI: Add fastmap bits to build.c
  UBI: Add self_check_eba()
  UBI: Export next_sqnum()
  UBI: Add fastmap stuff to ubi.h
  UBI: Add fastmap on-flash data structures

MAINTAINERS

@@ -7457,6 +7457,12 @@ F:	drivers/mtd/ubi/
 F:	include/linux/mtd/ubi.h
 F:	include/mtd/ubi-user.h
 
+UNSORTED BLOCK IMAGES (UBI) Fastmap
+M:	Richard Weinberger <richard@nod.at>
+L:	linux-mtd@lists.infradead.org
+S:	Maintained
+F:	drivers/mtd/ubi/fastmap.c
+
 USB ACM DRIVER
 M:	Oliver Neukum <oliver@neukum.org>
 L:	linux-usb@vger.kernel.org

drivers/mtd/ubi/Kconfig

@@ -56,6 +56,27 @@ config MTD_UBI_BEB_LIMIT
 
 	  Leave the default value if unsure.
 
+config MTD_UBI_FASTMAP
+	bool "UBI Fastmap (Experimental feature)"
+	default n
+	help
+	   Important: this feature is experimental so far and the on-flash
+	   format for fastmap may change in the next kernel versions
+
+	   Fastmap is a mechanism which allows attaching an UBI device
+	   in nearly constant time. Instead of scanning the whole MTD device it
+	   only has to locate a checkpoint (called fastmap) on the device.
+	   The on-flash fastmap contains all information needed to attach
+	   the device. Using fastmap makes only sense on large devices where
+	   attaching by scanning takes long. UBI will not automatically install
+	   a fastmap on old images, but you can set the UBI module parameter
+	   fm_autoconvert to 1 if you want so. Please note that fastmap-enabled
+	   images are still usable with UBI implementations without
+	   fastmap support. On typical flash devices the whole fastmap fits
+	   into one PEB. UBI will reserve PEBs to hold two fastmaps.
+
+	   If in doubt, say "N".
+
 config MTD_UBI_GLUEBI
 	tristate "MTD devices emulation driver (gluebi)"
 	help

drivers/mtd/ubi/Makefile

@@ -2,5 +2,6 @@ obj-$(CONFIG_MTD_UBI) += ubi.o
 
 ubi-y += vtbl.o vmt.o upd.o build.o cdev.o kapi.o eba.o io.o wl.o attach.o
 ubi-y += misc.o debug.o
+ubi-$(CONFIG_MTD_UBI_FASTMAP) += fastmap.o
 
 obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o

drivers/mtd/ubi/attach.c

@@ -300,7 +300,7 @@ static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
 }
 
 /**
- * compare_lebs - find out which logical eraseblock is newer.
+ * ubi_compare_lebs - find out which logical eraseblock is newer.
  * @ubi: UBI device description object
  * @aeb: first logical eraseblock to compare
  * @pnum: physical eraseblock number of the second logical eraseblock to
@@ -319,7 +319,7 @@ static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
  *     o bit 2 is cleared: the older LEB is not corrupted;
  *     o bit 2 is set: the older LEB is corrupted.
  */
-static int compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
+int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
 			int pnum, const struct ubi_vid_hdr *vid_hdr)
 {
 	void *buf;
@@ -337,7 +337,7 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
 		 * support these images anymore. Well, those images still work,
 		 * but only if no unclean reboots happened.
 		 */
-		ubi_err("unsupported on-flash UBI format\n");
+		ubi_err("unsupported on-flash UBI format");
 		return -EINVAL;
 	}
 
@@ -507,7 +507,7 @@ int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
 		 * sequence numbers. We still can attach these images, unless
 		 * there is a need to distinguish between old and new
 		 * eraseblocks, in which case we'll refuse the image in
-		 * 'compare_lebs()'. In other words, we attach old clean
+		 * 'ubi_compare_lebs()'. In other words, we attach old clean
 		 * images, but refuse attaching old images with duplicated
 		 * logical eraseblocks because there was an unclean reboot.
 		 */
@@ -523,7 +523,7 @@ int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
 		 * Now we have to drop the older one and preserve the newer
 		 * one.
 		 */
-		cmp_res = compare_lebs(ubi, aeb, pnum, vid_hdr);
+		cmp_res = ubi_compare_lebs(ubi, aeb, pnum, vid_hdr);
 		if (cmp_res < 0)
 			return cmp_res;
 
@@ -748,7 +748,7 @@ struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
 /**
  * check_corruption - check the data area of PEB.
  * @ubi: UBI device description object
- * @vid_hrd: the (corrupted) VID header of this PEB
+ * @vid_hdr: the (corrupted) VID header of this PEB
  * @pnum: the physical eraseblock number to check
  *
  * This is a helper function which is used to distinguish between VID header
@@ -810,6 +810,8 @@ static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
  * @ubi: UBI device description object
  * @ai: attaching information
  * @pnum: the physical eraseblock number
+ * @vid: The volume ID of the found volume will be stored in this pointer
+ * @sqnum: The sqnum of the found volume will be stored in this pointer
  *
  * This function reads UBI headers of PEB @pnum, checks them, and adds
  * information about this PEB to the corresponding list or RB-tree in the
@@ -817,10 +819,10 @@ static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
  * successfully handled and a negative error code in case of failure.
  */
 static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
-		    int pnum)
+		    int pnum, int *vid, unsigned long long *sqnum)
 {
 	long long uninitialized_var(ec);
-	int err, bitflips = 0, vol_id, ec_err = 0;
+	int err, bitflips = 0, vol_id = -1, ec_err = 0;
 
 	dbg_bld("scan PEB %d", pnum);
 
@@ -991,14 +993,21 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 	}
 
 	vol_id = be32_to_cpu(vidh->vol_id);
+	if (vid)
+		*vid = vol_id;
+	if (sqnum)
+		*sqnum = be64_to_cpu(vidh->sqnum);
 	if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 		int lnum = be32_to_cpu(vidh->lnum);
 
 		/* Unsupported internal volume */
 		switch (vidh->compat) {
 		case UBI_COMPAT_DELETE:
-			ubi_msg("\"delete\" compatible internal volume %d:%d found, will remove it",
-				vol_id, lnum);
+			if (vol_id != UBI_FM_SB_VOLUME_ID
+			    && vol_id != UBI_FM_DATA_VOLUME_ID) {
+				ubi_msg("\"delete\" compatible internal volume %d:%d found, will remove it",
+					vol_id, lnum);
+			}
 			err = add_to_list(ai, pnum, vol_id, lnum,
 					  ec, 1, &ai->erase);
 			if (err)
@@ -1120,52 +1129,127 @@ static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)
 	return 0;
 }
 
+/**
+ * destroy_av - free volume attaching information.
+ * @av: volume attaching information
+ * @ai: attaching information
+ *
+ * This function destroys the volume attaching information.
+ */
+static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
+{
+	struct ubi_ainf_peb *aeb;
+	struct rb_node *this = av->root.rb_node;
+
+	while (this) {
+		if (this->rb_left)
+			this = this->rb_left;
+		else if (this->rb_right)
+			this = this->rb_right;
+		else {
+			aeb = rb_entry(this, struct ubi_ainf_peb, u.rb);
+			this = rb_parent(this);
+			if (this) {
+				if (this->rb_left == &aeb->u.rb)
+					this->rb_left = NULL;
+				else
+					this->rb_right = NULL;
+			}
+
+			kmem_cache_free(ai->aeb_slab_cache, aeb);
+		}
+	}
+	kfree(av);
+}
+
+/**
+ * destroy_ai - destroy attaching information.
+ * @ai: attaching information
+ */
+static void destroy_ai(struct ubi_attach_info *ai)
+{
+	struct ubi_ainf_peb *aeb, *aeb_tmp;
+	struct ubi_ainf_volume *av;
+	struct rb_node *rb;
+
+	list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {
+		list_del(&aeb->u.list);
+		kmem_cache_free(ai->aeb_slab_cache, aeb);
+	}
+	list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
+		list_del(&aeb->u.list);
+		kmem_cache_free(ai->aeb_slab_cache, aeb);
+	}
+	list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
+		list_del(&aeb->u.list);
+		kmem_cache_free(ai->aeb_slab_cache, aeb);
+	}
+	list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
+		list_del(&aeb->u.list);
+		kmem_cache_free(ai->aeb_slab_cache, aeb);
+	}
+
+	/* Destroy the volume RB-tree */
+	rb = ai->volumes.rb_node;
+	while (rb) {
+		if (rb->rb_left)
+			rb = rb->rb_left;
+		else if (rb->rb_right)
+			rb = rb->rb_right;
+		else {
+			av = rb_entry(rb, struct ubi_ainf_volume, rb);
+
+			rb = rb_parent(rb);
+			if (rb) {
+				if (rb->rb_left == &av->rb)
+					rb->rb_left = NULL;
+				else
+					rb->rb_right = NULL;
+			}
+
+			destroy_av(ai, av);
+		}
+	}
+
+	if (ai->aeb_slab_cache)
+		kmem_cache_destroy(ai->aeb_slab_cache);
+
+	kfree(ai);
+}
+
 /**
  * scan_all - scan entire MTD device.
  * @ubi: UBI device description object
+ * @ai: attach info object
+ * @start: start scanning at this PEB
  *
  * This function does full scanning of an MTD device and returns complete
  * information about it in form of a "struct ubi_attach_info" object. In case
  * of failure, an error code is returned.
  */
-static struct ubi_attach_info *scan_all(struct ubi_device *ubi)
+static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
+		    int start)
 {
 	int err, pnum;
 	struct rb_node *rb1, *rb2;
 	struct ubi_ainf_volume *av;
 	struct ubi_ainf_peb *aeb;
-	struct ubi_attach_info *ai;
-
-	ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
-	if (!ai)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&ai->corr);
-	INIT_LIST_HEAD(&ai->free);
-	INIT_LIST_HEAD(&ai->erase);
-	INIT_LIST_HEAD(&ai->alien);
-	ai->volumes = RB_ROOT;
 
 	err = -ENOMEM;
-	ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
-					       sizeof(struct ubi_ainf_peb),
-					       0, 0, NULL);
-	if (!ai->aeb_slab_cache)
-		goto out_ai;
 
 	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 	if (!ech)
-		goto out_ai;
+		return err;
 
 	vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 	if (!vidh)
 		goto out_ech;
 
-	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
+	for (pnum = start; pnum < ubi->peb_count; pnum++) {
 		cond_resched();
 
 		dbg_gen("process PEB %d", pnum);
-		err = scan_peb(ubi, ai, pnum);
+		err = scan_peb(ubi, ai, pnum, NULL, NULL);
 		if (err < 0)
 			goto out_vidh;
 	}
@@ -1210,32 +1294,144 @@ static struct ubi_attach_info *scan_all(struct ubi_device *ubi)
 	ubi_free_vid_hdr(ubi, vidh);
 	kfree(ech);
 
-	return ai;
+	return 0;
 
 out_vidh:
 	ubi_free_vid_hdr(ubi, vidh);
 out_ech:
 	kfree(ech);
-out_ai:
-	ubi_destroy_ai(ai);
-	return ERR_PTR(err);
+	return err;
+}
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+
+/**
+ * scan_fastmap - try to find a fastmap and attach from it.
+ * @ubi: UBI device description object
+ * @ai: attach info object
+ *
+ * Returns 0 on success, negative return values indicate an internal
+ * error.
+ * UBI_NO_FASTMAP denotes that no fastmap was found.
+ * UBI_BAD_FASTMAP denotes that the found fastmap was invalid.
+ */
+static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info *ai)
+{
+	int err, pnum, fm_anchor = -1;
+	unsigned long long max_sqnum = 0;
+
+	err = -ENOMEM;
+
+	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+	if (!ech)
+		goto out;
+
+	vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+	if (!vidh)
+		goto out_ech;
+
+	for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
+		int vol_id = -1;
+		unsigned long long sqnum = -1;
+		cond_resched();
+
+		dbg_gen("process PEB %d", pnum);
+		err = scan_peb(ubi, ai, pnum, &vol_id, &sqnum);
+		if (err < 0)
+			goto out_vidh;
+
+		if (vol_id == UBI_FM_SB_VOLUME_ID && sqnum > max_sqnum) {
+			max_sqnum = sqnum;
+			fm_anchor = pnum;
+		}
+	}
+
+	ubi_free_vid_hdr(ubi, vidh);
+	kfree(ech);
+
+	if (fm_anchor < 0)
+		return UBI_NO_FASTMAP;
+
+	return ubi_scan_fastmap(ubi, ai, fm_anchor);
+
+out_vidh:
+	ubi_free_vid_hdr(ubi, vidh);
+out_ech:
+	kfree(ech);
+out:
+	return err;
+}
+
+#endif
+
+static struct ubi_attach_info *alloc_ai(const char *slab_name)
+{
+	struct ubi_attach_info *ai;
+
+	ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
+	if (!ai)
+		return ai;
+
+	INIT_LIST_HEAD(&ai->corr);
+	INIT_LIST_HEAD(&ai->free);
+	INIT_LIST_HEAD(&ai->erase);
+	INIT_LIST_HEAD(&ai->alien);
+	ai->volumes = RB_ROOT;
+	ai->aeb_slab_cache = kmem_cache_create(slab_name,
+					       sizeof(struct ubi_ainf_peb),
+					       0, 0, NULL);
+	if (!ai->aeb_slab_cache) {
+		kfree(ai);
+		ai = NULL;
+	}
+
+	return ai;
 }
 
 /**
  * ubi_attach - attach an MTD device.
  * @ubi: UBI device descriptor
+ * @force_scan: if set to non-zero attach by scanning
  *
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
-int ubi_attach(struct ubi_device *ubi)
+int ubi_attach(struct ubi_device *ubi, int force_scan)
 {
 	int err;
 	struct ubi_attach_info *ai;
 
-	ai = scan_all(ubi);
-	if (IS_ERR(ai))
-		return PTR_ERR(ai);
+	ai = alloc_ai("ubi_aeb_slab_cache");
+	if (!ai)
+		return -ENOMEM;
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	/* On small flash devices we disable fastmap in any case. */
+	if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) {
+		ubi->fm_disabled = 1;
+		force_scan = 1;
+	}
+
+	if (force_scan)
+		err = scan_all(ubi, ai, 0);
+	else {
+		err = scan_fast(ubi, ai);
+		if (err > 0) {
+			if (err != UBI_NO_FASTMAP) {
+				destroy_ai(ai);
+				ai = alloc_ai("ubi_aeb_slab_cache2");
+				if (!ai)
+					return -ENOMEM;
+			}
+
+			err = scan_all(ubi, ai, UBI_FM_MAX_START);
+		}
+	}
+#else
+	err = scan_all(ubi, ai, 0);
+#endif
+	if (err)
+		goto out_ai;
 
 	ubi->bad_peb_count = ai->bad_peb_count;
 	ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
@@ -1256,7 +1452,29 @@ int ubi_attach(struct ubi_device *ubi)
 	if (err)
 		goto out_wl;
 
-	ubi_destroy_ai(ai);
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	if (ubi->fm && ubi->dbg->chk_gen) {
+		struct ubi_attach_info *scan_ai;
+
+		scan_ai = alloc_ai("ubi_ckh_aeb_slab_cache");
+		if (!scan_ai)
+			goto out_wl;
+
+		err = scan_all(ubi, scan_ai, 0);
+		if (err) {
+			destroy_ai(scan_ai);
+			goto out_wl;
+		}
+
+		err = self_check_eba(ubi, ai, scan_ai);
+		destroy_ai(scan_ai);
+
+		if (err)
+			goto out_wl;
+	}
+#endif
+
+	destroy_ai(ai);
 	return 0;
 
 out_wl:
@@ -1265,98 +1483,10 @@ int ubi_attach(struct ubi_device *ubi)
 	ubi_free_internal_volumes(ubi);
 	vfree(ubi->vtbl);
 out_ai:
-	ubi_destroy_ai(ai);
+	destroy_ai(ai);
 	return err;
 }
 
-/**
- * destroy_av - free volume attaching information.
- * @av: volume attaching information
- * @ai: attaching information
- *
- * This function destroys the volume attaching information.
- */
-static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
-{
-	struct ubi_ainf_peb *aeb;
-	struct rb_node *this = av->root.rb_node;
-
-	while (this) {
-		if (this->rb_left)
-			this = this->rb_left;
-		else if (this->rb_right)
-			this = this->rb_right;
-		else {
-			aeb = rb_entry(this, struct ubi_ainf_peb, u.rb);
-			this = rb_parent(this);
-			if (this) {
-				if (this->rb_left == &aeb->u.rb)
-					this->rb_left = NULL;
-				else
-					this->rb_right = NULL;
-			}
-
-			kmem_cache_free(ai->aeb_slab_cache, aeb);
-		}
-	}
-	kfree(av);
-}
-
-/**
- * ubi_destroy_ai - destroy attaching information.
- * @ai: attaching information
- */
-void ubi_destroy_ai(struct ubi_attach_info *ai)
-{
-	struct ubi_ainf_peb *aeb, *aeb_tmp;
-	struct ubi_ainf_volume *av;
-	struct rb_node *rb;
-
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-
-	/* Destroy the volume RB-tree */
-	rb = ai->volumes.rb_node;
-	while (rb) {
-		if (rb->rb_left)
-			rb = rb->rb_left;
-		else if (rb->rb_right)
-			rb = rb->rb_right;
-		else {
-			av = rb_entry(rb, struct ubi_ainf_volume, rb);
-
-			rb = rb_parent(rb);
-			if (rb) {
-				if (rb->rb_left == &av->rb)
-					rb->rb_left = NULL;
-				else
-					rb->rb_right = NULL;
-			}
-
-			destroy_av(ai, av);
-		}
-	}
-
-	if (ai->aeb_slab_cache)
-		kmem_cache_destroy(ai->aeb_slab_cache);
-
-	kfree(ai);
-}
-
 /**
  * self_check_ai - check the attaching information.
  * @ubi: UBI device description object

drivers/mtd/ubi/build.c

@@ -76,7 +76,10 @@ static int __initdata mtd_devs;
 
 /* MTD devices specification parameters */
 static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
-
+#ifdef CONFIG_MTD_UBI_FASTMAP
+/* UBI module parameter to enable fastmap automatically on non-fastmap images */
+static bool fm_autoconvert;
+#endif
 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
 struct class *ubi_class;
 
@@ -153,6 +156,19 @@ int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
 
 	ubi_do_get_device_info(ubi, &nt.di);
 	ubi_do_get_volume_info(ubi, vol, &nt.vi);
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	switch (ntype) {
+	case UBI_VOLUME_ADDED:
+	case UBI_VOLUME_REMOVED:
+	case UBI_VOLUME_RESIZED:
+	case UBI_VOLUME_RENAMED:
+		if (ubi_update_fastmap(ubi)) {
+			ubi_err("Unable to update fastmap!");
+			ubi_ro_mode(ubi);
+		}
+	}
+#endif
 	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
 }
 
@@ -918,10 +934,40 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 	ubi->vid_hdr_offset = vid_hdr_offset;
 	ubi->autoresize_vol_id = -1;
 
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	ubi->fm_pool.used = ubi->fm_pool.size = 0;
+	ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
+
+	/*
+	 * fm_pool.max_size is 5% of the total number of PEBs but it's also
+	 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
+	 */
+	ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
+		ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
+	if (ubi->fm_pool.max_size < UBI_FM_MIN_POOL_SIZE)
+		ubi->fm_pool.max_size = UBI_FM_MIN_POOL_SIZE;
+
+	ubi->fm_wl_pool.max_size = UBI_FM_WL_POOL_SIZE;
+	ubi->fm_disabled = !fm_autoconvert;
+
+	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
+	    <= UBI_FM_MAX_START) {
+		ubi_err("More than %i PEBs are needed for fastmap, sorry.",
+			UBI_FM_MAX_START);
+		ubi->fm_disabled = 1;
+	}
+
+	ubi_msg("default fastmap pool size: %d", ubi->fm_pool.max_size);
+	ubi_msg("default fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
+#else
+	ubi->fm_disabled = 1;
+#endif
 	mutex_init(&ubi->buf_mutex);
 	mutex_init(&ubi->ckvol_mutex);
 	mutex_init(&ubi->device_mutex);
 	spin_lock_init(&ubi->volumes_lock);
+	mutex_init(&ubi->fm_mutex);
+	init_rwsem(&ubi->fm_sem);
 
 	ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
 
@@ -934,11 +980,17 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 	if (!ubi->peb_buf)
 		goto out_free;
 
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	ubi->fm_size = ubi_calc_fm_size(ubi);
+	ubi->fm_buf = vzalloc(ubi->fm_size);
+	if (!ubi->fm_buf)
+		goto out_free;
+#endif
 	err = ubi_debugging_init_dev(ubi);
 	if (err)
 		goto out_free;
 
-	err = ubi_attach(ubi);
+	err = ubi_attach(ubi, 0);
 	if (err) {
 		ubi_err("failed to attach mtd%d, error %d", mtd->index, err);
 		goto out_debugging;
@@ -1012,6 +1064,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 	ubi_debugging_exit_dev(ubi);
 out_free:
 	vfree(ubi->peb_buf);
+	vfree(ubi->fm_buf);
 	if (ref)
 		put_device(&ubi->dev);
 	else
@@ -1061,7 +1114,11 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	ubi_assert(ubi_num == ubi->ubi_num);
 	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
 	ubi_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
-
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	/* If we don't write a new fastmap at detach time we lose all
+	 * EC updates that have been made since the last written fastmap. */
+	ubi_update_fastmap(ubi);
+#endif
 	/*
 	 * Before freeing anything, we have to stop the background thread to
 	 * prevent it from doing anything on this device while we are freeing.
@@ -1077,12 +1134,14 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 
 	ubi_debugfs_exit_dev(ubi);
 	uif_close(ubi);
+
 	ubi_wl_close(ubi);
 	ubi_free_internal_volumes(ubi);
 	vfree(ubi->vtbl);
 	put_mtd_device(ubi->mtd);
 	ubi_debugging_exit_dev(ubi);
 	vfree(ubi->peb_buf);
+	vfree(ubi->fm_buf);
 	ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
 	put_device(&ubi->dev);
 	return 0;
@@ -1404,7 +1463,10 @@ MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|pa
 		      "Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
 		      "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
 		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
-
+#ifdef CONFIG_MTD_UBI_FASTMAP
+module_param(fm_autoconvert, bool, 0644);
+MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
+#endif
 MODULE_VERSION(__stringify(UBI_VERSION));
 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
 MODULE_AUTHOR("Artem Bityutskiy");

drivers/mtd/ubi/eba.c

@@ -57,7 +57,7 @@
  * 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;
 
@@ -340,7 +340,9 @@ int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 
 	dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
 
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
+	up_read(&ubi->fm_sem);
 	err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 0);
 
 out_unlock:
@@ -521,7 +523,7 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
 		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;
@@ -548,7 +550,9 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
 	mutex_unlock(&ubi->buf_mutex);
 	ubi_free_vid_hdr(ubi, vid_hdr);
 
+	down_read(&ubi->fm_sem);
 	vol->eba_tbl[lnum] = new_pnum;
+	up_read(&ubi->fm_sem);
 	ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
 
 	ubi_msg("data was successfully recovered");
@@ -632,7 +636,7 @@ int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 	}
 
 	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);
@@ -665,7 +669,9 @@ int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 		}
 	}
 
+	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);
@@ -692,7 +698,7 @@ int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 		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;
 }
@@ -745,7 +751,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 		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);
@@ -783,7 +789,9 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 	}
 
 	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);
@@ -810,7 +818,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 		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;
 }
@@ -862,7 +870,7 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 	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);
@@ -904,7 +912,9 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 			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);
@@ -930,7 +940,7 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 		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;
 }
@@ -1089,7 +1099,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 		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) {
@@ -1151,7 +1161,9 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 	}
 
 	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);
@@ -1201,6 +1213,102 @@ static void print_rsvd_warning(struct ubi_device *ubi,
 			 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

drivers/mtd/ubi/ubi-media.h

@@ -375,4 +375,141 @@ struct ubi_vtbl_record {
 	__be32  crc;
 } __packed;
 
+/* UBI fastmap on-flash data structures */
+
+#define UBI_FM_SB_VOLUME_ID	(UBI_LAYOUT_VOLUME_ID + 1)
+#define UBI_FM_DATA_VOLUME_ID	(UBI_LAYOUT_VOLUME_ID + 2)
+
+/* fastmap on-flash data structure format version */
+#define UBI_FM_FMT_VERSION	1
+
+#define UBI_FM_SB_MAGIC		0x7B11D69F
+#define UBI_FM_HDR_MAGIC	0xD4B82EF7
+#define UBI_FM_VHDR_MAGIC	0xFA370ED1
+#define UBI_FM_POOL_MAGIC	0x67AF4D08
+#define UBI_FM_EBA_MAGIC	0xf0c040a8
+
+/* A fastmap supber block can be located between PEB 0 and
+ * UBI_FM_MAX_START */
+#define UBI_FM_MAX_START	64
+
+/* A fastmap can use up to UBI_FM_MAX_BLOCKS PEBs */
+#define UBI_FM_MAX_BLOCKS	32
+
+/* 5% of the total number of PEBs have to be scanned while attaching
+ * from a fastmap.
+ * But the size of this pool is limited to be between UBI_FM_MIN_POOL_SIZE and
+ * UBI_FM_MAX_POOL_SIZE */
+#define UBI_FM_MIN_POOL_SIZE	8
+#define UBI_FM_MAX_POOL_SIZE	256
+
+#define UBI_FM_WL_POOL_SIZE	25
+
+/**
+ * struct ubi_fm_sb - UBI fastmap super block
+ * @magic: fastmap super block magic number (%UBI_FM_SB_MAGIC)
+ * @version: format version of this fastmap
+ * @data_crc: CRC over the fastmap data
+ * @used_blocks: number of PEBs used by this fastmap
+ * @block_loc: an array containing the location of all PEBs of the fastmap
+ * @block_ec: the erase counter of each used PEB
+ * @sqnum: highest sequence number value at the time while taking the fastmap
+ *
+ */
+struct ubi_fm_sb {
+	__be32 magic;
+	__u8 version;
+	__u8 padding1[3];
+	__be32 data_crc;
+	__be32 used_blocks;
+	__be32 block_loc[UBI_FM_MAX_BLOCKS];
+	__be32 block_ec[UBI_FM_MAX_BLOCKS];
+	__be64 sqnum;
+	__u8 padding2[32];
+} __packed;
+
+/**
+ * struct ubi_fm_hdr - header of the fastmap data set
+ * @magic: fastmap header magic number (%UBI_FM_HDR_MAGIC)
+ * @free_peb_count: number of free PEBs known by this fastmap
+ * @used_peb_count: number of used PEBs known by this fastmap
+ * @scrub_peb_count: number of to be scrubbed PEBs known by this fastmap
+ * @bad_peb_count: number of bad PEBs known by this fastmap
+ * @erase_peb_count: number of bad PEBs which have to be erased
+ * @vol_count: number of UBI volumes known by this fastmap
+ */
+struct ubi_fm_hdr {
+	__be32 magic;
+	__be32 free_peb_count;
+	__be32 used_peb_count;
+	__be32 scrub_peb_count;
+	__be32 bad_peb_count;
+	__be32 erase_peb_count;
+	__be32 vol_count;
+	__u8 padding[4];
+} __packed;
+
+/* struct ubi_fm_hdr is followed by two struct ubi_fm_scan_pool */
+
+/**
+ * struct ubi_fm_scan_pool - Fastmap pool PEBs to be scanned while attaching
+ * @magic: pool magic numer (%UBI_FM_POOL_MAGIC)
+ * @size: current pool size
+ * @max_size: maximal pool size
+ * @pebs: an array containing the location of all PEBs in this pool
+ */
+struct ubi_fm_scan_pool {
+	__be32 magic;
+	__be16 size;
+	__be16 max_size;
+	__be32 pebs[UBI_FM_MAX_POOL_SIZE];
+	__be32 padding[4];
+} __packed;
+
+/* ubi_fm_scan_pool is followed by nfree+nused struct ubi_fm_ec records */
+
+/**
+ * struct ubi_fm_ec - stores the erase counter of a PEB
+ * @pnum: PEB number
+ * @ec: ec of this PEB
+ */
+struct ubi_fm_ec {
+	__be32 pnum;
+	__be32 ec;
+} __packed;
+
+/**
+ * struct ubi_fm_volhdr - Fastmap volume header
+ * it identifies the start of an eba table
+ * @magic: Fastmap volume header magic number (%UBI_FM_VHDR_MAGIC)
+ * @vol_id: volume id of the fastmapped volume
+ * @vol_type: type of the fastmapped volume
+ * @data_pad: data_pad value of the fastmapped volume
+ * @used_ebs: number of used LEBs within this volume
+ * @last_eb_bytes: number of bytes used in the last LEB
+ */
+struct ubi_fm_volhdr {
+	__be32 magic;
+	__be32 vol_id;
+	__u8 vol_type;
+	__u8 padding1[3];
+	__be32 data_pad;
+	__be32 used_ebs;
+	__be32 last_eb_bytes;
+	__u8 padding2[8];
+} __packed;
+
+/* struct ubi_fm_volhdr is followed by one struct ubi_fm_eba records */
+
+/**
+ * struct ubi_fm_eba - denotes an association beween a PEB and LEB
+ * @magic: EBA table magic number
+ * @reserved_pebs: number of table entries
+ * @pnum: PEB number of LEB (LEB is the index)
+ */
+struct ubi_fm_eba {
+	__be32 magic;
+	__be32 reserved_pebs;
+	__be32 pnum[0];
+} __packed;
 #endif /* !__UBI_MEDIA_H__ */

drivers/mtd/ubi/ubi.h

@@ -133,6 +133,17 @@ enum {
 	MOVE_RETRY,
 };
 
+/*
+ * Return codes of the fastmap sub-system
+ *
+ * UBI_NO_FASTMAP: No fastmap super block was found
+ * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
+ */
+enum {
+	UBI_NO_FASTMAP = 1,
+	UBI_BAD_FASTMAP,
+};
+
 /**
  * struct ubi_wl_entry - wear-leveling entry.
  * @u.rb: link in the corresponding (free/used) RB-tree
@@ -198,6 +209,41 @@ struct ubi_rename_entry {
 
 struct ubi_volume_desc;
 
+/**
+ * struct ubi_fastmap_layout - in-memory fastmap data structure.
+ * @e: PEBs used by the current fastmap
+ * @to_be_tortured: if non-zero tortured this PEB
+ * @used_blocks: number of used PEBs
+ * @max_pool_size: maximal size of the user pool
+ * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
+ */
+struct ubi_fastmap_layout {
+	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
+	int to_be_tortured[UBI_FM_MAX_BLOCKS];
+	int used_blocks;
+	int max_pool_size;
+	int max_wl_pool_size;
+};
+
+/**
+ * struct ubi_fm_pool - in-memory fastmap pool
+ * @pebs: PEBs in this pool
+ * @used: number of used PEBs
+ * @size: total number of PEBs in this pool
+ * @max_size: maximal size of the pool
+ *
+ * A pool gets filled with up to max_size.
+ * If all PEBs within the pool are used a new fastmap will be written
+ * to the flash and the pool gets refilled with empty PEBs.
+ *
+ */
+struct ubi_fm_pool {
+	int pebs[UBI_FM_MAX_POOL_SIZE];
+	int used;
+	int size;
+	int max_size;
+};
+
 /**
  * struct ubi_volume - UBI volume description data structure.
  * @dev: device object to make use of the the Linux device model
@@ -333,9 +379,21 @@ struct ubi_wl_entry;
  * @ltree: the lock tree
  * @alc_mutex: serializes "atomic LEB change" operations
  *
+ * @fm_disabled: non-zero if fastmap is disabled (default)
+ * @fm: in-memory data structure of the currently used fastmap
+ * @fm_pool: in-memory data structure of the fastmap pool
+ * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
+ *		sub-system
+ * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf
+ * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
+ * @fm_size: fastmap size in bytes
+ * @fm_sem: allows ubi_update_fastmap() to block EBA table changes
+ * @fm_work: fastmap work queue
+ *
  * @used: RB-tree of used physical eraseblocks
  * @erroneous: RB-tree of erroneous used physical eraseblocks
  * @free: RB-tree of free physical eraseblocks
+ * @free_count: Contains the number of elements in @free
  * @scrub: RB-tree of physical eraseblocks which need scrubbing
  * @pq: protection queue (contain physical eraseblocks which are temporarily
  *      protected from the wear-leveling worker)
@@ -426,10 +484,22 @@ struct ubi_device {
 	struct rb_root ltree;
 	struct mutex alc_mutex;
 
+	/* Fastmap stuff */
+	int fm_disabled;
+	struct ubi_fastmap_layout *fm;
+	struct ubi_fm_pool fm_pool;
+	struct ubi_fm_pool fm_wl_pool;
+	struct rw_semaphore fm_sem;
+	struct mutex fm_mutex;
+	void *fm_buf;
+	size_t fm_size;
+	struct work_struct fm_work;
+
 	/* Wear-leveling sub-system's stuff */
 	struct rb_root used;
 	struct rb_root erroneous;
 	struct rb_root free;
+	int free_count;
 	struct rb_root scrub;
 	struct list_head pq[UBI_PROT_QUEUE_LEN];
 	int pq_head;
@@ -596,6 +666,32 @@ struct ubi_attach_info {
 	struct kmem_cache *aeb_slab_cache;
 };
 
+/**
+ * struct ubi_work - UBI work description data structure.
+ * @list: a link in the list of pending works
+ * @func: worker function
+ * @e: physical eraseblock to erase
+ * @vol_id: the volume ID on which this erasure is being performed
+ * @lnum: the logical eraseblock number
+ * @torture: if the physical eraseblock has to be tortured
+ * @anchor: produce a anchor PEB to by used by fastmap
+ *
+ * The @func pointer points to the worker function. If the @cancel argument is
+ * not zero, the worker has to free the resources and exit immediately. The
+ * worker has to return zero in case of success and a negative error code in
+ * case of failure.
+ */
+struct ubi_work {
+	struct list_head list;
+	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel);
+	/* The below fields are only relevant to erasure works */
+	struct ubi_wl_entry *e;
+	int vol_id;
+	int lnum;
+	int torture;
+	int anchor;
+};
+
 #include "debug.h"
 
 extern struct kmem_cache *ubi_wl_entry_slab;
@@ -606,7 +702,7 @@ extern struct class *ubi_class;
 extern struct mutex ubi_devices_mutex;
 extern struct blocking_notifier_head ubi_notifiers;
 
-/* scan.c */
+/* attach.c */
 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
@@ -614,7 +710,7 @@ struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
 				       struct ubi_attach_info *ai);
-int ubi_attach(struct ubi_device *ubi);
+int ubi_attach(struct ubi_device *ubi, int force_scan);
 void ubi_destroy_ai(struct ubi_attach_info *ai);
 
 /* vtbl.c */
@@ -664,6 +760,9 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 		     struct ubi_vid_hdr *vid_hdr);
 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
+unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
+int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
+		   struct ubi_attach_info *ai_scan);
 
 /* wl.c */
 int ubi_wl_get_peb(struct ubi_device *ubi);
@@ -674,6 +773,12 @@ int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
 void ubi_wl_close(struct ubi_device *ubi);
 int ubi_thread(void *u);
+struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
+int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
+		      int lnum, int torture);
+int ubi_is_erase_work(struct ubi_work *wrk);
+void ubi_refill_pools(struct ubi_device *ubi);
+int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
 
 /* io.c */
 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
@@ -711,6 +816,15 @@ void ubi_free_internal_volumes(struct ubi_device *ubi);
 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
 			    struct ubi_volume_info *vi);
+/* scan.c */
+int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
+		      int pnum, const struct ubi_vid_hdr *vid_hdr);
+
+/* fastmap.c */
+size_t ubi_calc_fm_size(struct ubi_device *ubi);
+int ubi_update_fastmap(struct ubi_device *ubi);
+int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
+		     int fm_anchor);
 
 /*
  * ubi_rb_for_each_entry - walk an RB-tree.