[PATCH] [RFC] UBI: Implement Fastmap support

From: Richard Weinberger
Date: Mon May 21 2012 - 10:02:16 EST

Fastmap (aka checkpointing) allows attaching of an UBI volume in nearly
constant time. Only a fixed number of PEBs has to be scanned.

Signed-off-by: Richard Weinberger <richard@xxxxxx>
---
drivers/mtd/ubi/Makefile | 2 +-
drivers/mtd/ubi/attach.c | 68 +++-
drivers/mtd/ubi/build.c | 23 +
drivers/mtd/ubi/eba.c | 18 +-
drivers/mtd/ubi/fastmap.c | 1132 +++++++++++++++++++++++++++++++++++++++++++
drivers/mtd/ubi/ubi-media.h | 118 +++++
drivers/mtd/ubi/ubi.h | 61 +++-
drivers/mtd/ubi/wl.c | 170 +++++++-
8 files changed, 1568 insertions(+), 24 deletions(-)
create mode 100644 drivers/mtd/ubi/fastmap.c

diff --git a/drivers/mtd/ubi/Makefile b/drivers/mtd/ubi/Makefile
index a0803ac..c9f0269 100644
--- a/drivers/mtd/ubi/Makefile
+++ b/drivers/mtd/ubi/Makefile
@@ -1,6 +1,6 @@
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-y += fastmap.o misc.o debug.o

obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o
diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c
index f59f748..f044884 100644
--- a/drivers/mtd/ubi/attach.c
+++ b/drivers/mtd/ubi/attach.c
@@ -294,7 +294,7 @@ 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
@@ -313,7 +313,7 @@ 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;
@@ -501,7 +501,7 @@ 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.
*/
@@ -517,7 +517,7 @@ 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;

@@ -977,7 +977,12 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
}

vol_id = be32_to_cpu(vidh->vol_id);
- if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
+
+ if (vol_id > UBI_MAX_VOLUMES &&
+ vol_id != UBI_LAYOUT_VOLUME_ID &&
+ ((vol_id != UBI_FM_SB_VOLUME_ID &&
+ vol_id != UBI_FM_DATA_VOLUME_ID) ||
+ ubi->attached_by_scanning == true)) {
int lnum = be32_to_cpu(vidh->lnum);

/* Unsupported internal volume */
@@ -1208,18 +1213,34 @@ out_ai:
}

/**
- * ubi_attach - attach an MTD device.
- * @ubi: UBI device descriptor
+ * scan_fastmap - attach MTD device using fastmap.
+ * @ubi: UBI device description object
*
- * This function returns zero in case of success and a negative error code in
- * case of failure.
+ * This function attaches a MTD device using a fastmap and returns complete
+ * information about it in form of a "struct ubi_attach_info" object. In case
+ * of failure, an error code is returned.
*/
-int ubi_attach(struct ubi_device *ubi)
+static struct ubi_attach_info *scan_fastmap(struct ubi_device *ubi)
+{
+ int fm_start;
+
+ fm_start = ubi_find_fastmap(ubi);
+ if (fm_start < 0)
+ return ERR_PTR(-ENOENT);
+
+ return ubi_read_fastmap(ubi, fm_start);
+}
+
+static int do_attach(struct ubi_device *ubi, bool fullscan)
{
int err;
struct ubi_attach_info *ai;

- ai = scan_all(ubi);
+ if (fullscan)
+ ai = scan_all(ubi);
+ else
+ ai = scan_fastmap(ubi);
+
if (IS_ERR(ai))
return PTR_ERR(ai);

@@ -1256,6 +1277,31 @@ out_ai:
}

/**
+ * ubi_attach - attach an MTD device.
+ * @ubi: UBI device descriptor
+ *
+ * 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 err;
+
+ err = do_attach(ubi, false);
+ if (err) {
+ if (err != -ENOENT)
+ ubi_err("Attach by fastmap failed! " \
+ "Falling back to attach by scanning. " \
+ "error = %i\n", err);
+
+ ubi->attached_by_scanning = true;
+ err = do_attach(ubi, true);
+ }
+
+ return err;
+}
+
+/**
* destroy_av - free volume attaching information.
* @av: volume attaching information
* @ai: attaching information
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 2c5ed5c..ef5d7b7 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -144,6 +144,16 @@ 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);
+
+ 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!");
+ }
+
return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
}

@@ -874,6 +884,19 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
ubi->vid_hdr_offset = vid_hdr_offset;
ubi->autoresize_vol_id = -1;

+ ubi->fm_pool.used = ubi->fm_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((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_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
+
mutex_init(&ubi->buf_mutex);
mutex_init(&ubi->ckvol_mutex);
mutex_init(&ubi->device_mutex);
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 5fa726f..654f121 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/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;

@@ -522,7 +522,7 @@ retry:
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;
@@ -633,7 +633,7 @@ 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);
@@ -694,7 +694,7 @@ write_error:
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;
}
@@ -747,7 +747,7 @@ 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);
@@ -812,7 +812,7 @@ write_error:
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;
}
@@ -864,7 +864,7 @@ 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);
@@ -932,7 +932,7 @@ write_error:
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;
}
@@ -1092,7 +1092,7 @@ 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) {
diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
new file mode 100644
index 0000000..2d1056e
--- /dev/null
+++ b/drivers/mtd/ubi/fastmap.c
@@ -0,0 +1,1132 @@
+/*
+ * Copyright (c) 2012 Linutronix GmbH
+ * Author: Richard Weinberger <richard@xxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ */
+
+#include <linux/crc32.h>
+#include "ubi.h"
+
+/**
+ * new_fm_vhdr - allocate a new volume header for fastmap usage.
+ * @ubi: UBI device description object
+ * @vol_id: the VID of the new header
+ */
+static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
+{
+ struct ubi_vid_hdr *new;
+
+ new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!new)
+ goto out;
+
+ new->vol_type = UBI_VID_DYNAMIC;
+ new->vol_id = cpu_to_be32(vol_id);
+
+ /* UBI implementations without fastmap support have to delete the
+ * fastmap.
+ */
+ new->compat = UBI_COMPAT_DELETE;
+
+out:
+ return new;
+}
+
+/**
+ * add_aeb - create and add a attach erase block to a given list.
+ * @ai: UBI attach info object
+ * @list: the target list
+ * @pnum: PEB number of the new attach erase block
+ * @ec: erease counter of the new LEB
+ */
+static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
+ int pnum, int ec)
+{
+ struct ubi_ainf_peb *aeb;
+
+ aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
+ if (!aeb)
+ return -ENOMEM;
+
+ aeb->pnum = pnum;
+ aeb->ec = ec;
+ aeb->lnum = -1;
+ aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
+
+ ai->ec_sum += aeb->ec;
+ ai->ec_count++;
+
+ if (ai->max_ec < aeb->ec)
+ ai->max_ec = aeb->ec;
+
+ if (ai->min_ec > aeb->ec)
+ ai->min_ec = aeb->ec;
+
+ list_add_tail(&aeb->u.list, list);
+
+ return 0;
+}
+
+/**
+ * add_vol - create and add a new scan volume to ubi_attach_info.
+ * @ai: ubi_attach_info object
+ * @vol_id: VID of the new volume
+ * @used_ebs: number of used EBS
+ * @data_pad: data padding value of the new volume
+ * @vol_type: volume type
+ * @last_eb_bytes: number of bytes in the last LEB
+ */
+static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
+ int used_ebs, int data_pad, u8 vol_type,
+ int last_eb_bytes)
+{
+ struct ubi_ainf_volume *av;
+ struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
+
+ while (*p) {
+ parent = *p;
+ av = rb_entry(parent, struct ubi_ainf_volume, rb);
+
+ if (vol_id > av->vol_id)
+ p = &(*p)->rb_left;
+ else if (vol_id > av->vol_id)
+ p = &(*p)->rb_right;
+ }
+
+ av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
+ if (!av)
+ goto out;
+
+ av->highest_lnum = av->leb_count = 0;
+ av->vol_id = vol_id;
+ av->used_ebs = used_ebs;
+ av->data_pad = data_pad;
+ av->last_data_size = last_eb_bytes;
+ av->compat = 0;
+ av->vol_type = vol_type;
+ av->root = RB_ROOT;
+
+ dbg_bld("Found volume (volid %i)", vol_id);
+
+ rb_link_node(&av->rb, parent, p);
+ rb_insert_color(&av->rb, &ai->volumes);
+
+out:
+ return av;
+}
+
+/**
+ * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
+ * from it's original list.
+ * @ai: ubi_attach_info object
+ * @aeb: the to be assigned SEB
+ * @av: target scan volume
+ */
+static void assign_aeb_to_av(struct ubi_attach_info *ai,
+ struct ubi_ainf_peb *aeb,
+ struct ubi_ainf_volume *av)
+{
+ struct ubi_ainf_peb *tmp_aeb;
+ struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
+
+ p = &av->root.rb_node;
+ while (*p) {
+ parent = *p;
+
+ tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
+ if (aeb->lnum != tmp_aeb->lnum) {
+ if (aeb->lnum < tmp_aeb->lnum)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+
+ continue;
+ } else
+ break;
+ }
+
+ list_del(&aeb->u.list);
+ av->leb_count++;
+
+ rb_link_node(&aeb->u.rb, parent, p);
+ rb_insert_color(&aeb->u.rb, &av->root);
+}
+
+/**
+ * update_vol - inserts or updates a LEB which was found a pool.
+ * @ubi: the UBI device object
+ * @ai: attach info object
+ * @av: the volume this LEB belongs to
+ * @new_vh: the volume header derived from new_aeb
+ * @new_aeb: the AEB to be examined
+ */
+static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
+ struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
+ struct ubi_ainf_peb *new_aeb)
+{
+ struct rb_node **p = &av->root.rb_node, *parent = NULL;
+ struct ubi_ainf_peb *aeb, *victim;
+ int cmp_res;
+
+ while (*p) {
+ parent = *p;
+ aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
+
+ if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
+ if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+
+ continue;
+ }
+
+ /* This case can happen if the fastmap gets written
+ * because of a volume change (creation, deletion, ..).
+ * Then a PEB can be within the persistent EBA and the pool.
+ */
+ if (aeb->pnum == new_aeb->pnum) {
+ kmem_cache_free(ai->aeb_slab_cache, new_aeb);
+
+ return 0;
+ }
+
+ cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
+ if (cmp_res < 0)
+ return cmp_res;
+
+ /* new_aeb is newer */
+ if (cmp_res & 1) {
+ victim = kmem_cache_alloc(ai->aeb_slab_cache,
+ GFP_KERNEL);
+ if (!victim)
+ return -ENOMEM;
+
+ victim->ec = aeb->ec;
+ victim->pnum = aeb->pnum;
+ list_add_tail(&victim->u.list, &ai->erase);
+
+ if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
+ av->last_data_size = \
+ be32_to_cpu(new_vh->data_size);
+
+ aeb->ec = new_aeb->ec;
+ aeb->pnum = new_aeb->pnum;
+ aeb->copy_flag = new_vh->copy_flag;
+ kmem_cache_free(ai->aeb_slab_cache, new_aeb);
+
+ /* new_aeb is older */
+ } else {
+ dbg_bld("Vol %i: AEB %i's PEB %i is old, dropping it\n",
+ av->vol_id, aeb->lnum, new_aeb->pnum);
+ list_add_tail(&new_aeb->u.list, &ai->erase);
+ }
+
+ return 0;
+ }
+ /* This LEB is new, let's add it to the volume */
+
+ if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
+ av->highest_lnum = be32_to_cpu(new_vh->lnum);
+ av->last_data_size = be32_to_cpu(new_vh->data_size);
+ }
+
+ if (av->vol_type == UBI_STATIC_VOLUME)
+ av->used_ebs = be32_to_cpu(new_vh->used_ebs);
+
+ av->leb_count++;
+
+ rb_link_node(&new_aeb->u.rb, parent, p);
+ rb_insert_color(&new_aeb->u.rb, &av->root);
+
+ return 0;
+}
+
+/**
+ * process_pool_aeb - we found a non-empty PEB in a pool
+ * @ubi: UBI device object
+ * @ai: attach info object
+ * @new_vh: the volume header derived from new_aeb
+ * @new_aeb: the AEB to be examined
+ */
+static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
+ struct ubi_vid_hdr *new_vh,
+ struct ubi_ainf_peb *new_aeb)
+{
+ struct ubi_ainf_volume *av, *tmp_av = NULL;
+ struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
+ int found = 0;
+
+ if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
+ be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
+ kmem_cache_free(ai->aeb_slab_cache, new_aeb);
+
+ return 0;
+ }
+
+ /* Find the volume this SEB belongs to */
+ while (*p) {
+ parent = *p;
+ tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
+
+ if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
+ p = &(*p)->rb_left;
+ else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
+ p = &(*p)->rb_right;
+ else {
+ found = 1;
+ break;
+ }
+ }
+
+ if (found)
+ av = tmp_av;
+ else {
+ ubi_err("Orphaned volume in fastmap pool!");
+
+ return -EINVAL;
+ }
+
+ ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
+
+ return update_vol(ubi, ai, av, new_vh, new_aeb);
+}
+
+/**
+ * scan_pool - scans a pool for changed (no longer empty PEBs)
+ * @ubi: UBI device object
+ * @ai: attach info object
+ * @pebs: an array of all PEB numbers in the to be scanned pool
+ * @pool_size: size of the pool (number of entries in @pebs)
+ * @max_sqnum: pointer to the maximal sequence number
+ */
+static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
+ int *pebs, int pool_size, unsigned long long *max_sqnum)
+{
+ struct ubi_vid_hdr *vh;
+ struct ubi_ec_hdr *ech;
+ struct ubi_ainf_peb *new_aeb;
+ int i;
+ int pnum;
+ int err;
+ int ret = 0;
+
+ ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ if (!ech)
+ return -ENOMEM;
+
+ vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vh) {
+ kfree(ech);
+ return -ENOMEM;
+ }
+
+ /*
+ * Now scan all PEBs in the pool to find changes which have been made
+ * after the creation of the fastmap
+ */
+ for (i = 0; i < pool_size; i++) {
+ pnum = be32_to_cpu(pebs[i]);
+
+ err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
+
+ if (err == UBI_IO_FF)
+ continue;
+ else if (err == 0) {
+ err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
+ if (err) {
+ ret = err;
+
+ goto out;
+ }
+
+ new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
+ GFP_KERNEL);
+ if (!new_aeb) {
+ ret = -ENOMEM;
+
+ goto out;
+ }
+
+ new_aeb->ec = be64_to_cpu(ech->ec);
+ new_aeb->pnum = pnum;
+ new_aeb->lnum = be32_to_cpu(vh->lnum);
+ new_aeb->sqnum = be64_to_cpu(vh->sqnum);
+ new_aeb->copy_flag = vh->copy_flag;
+ new_aeb->scrub = 0;
+
+ err = process_pool_aeb(ubi, ai, vh, new_aeb);
+ if (err) {
+ ret = err;
+
+ goto out;
+ }
+
+ if (*max_sqnum < new_aeb->sqnum)
+ *max_sqnum = new_aeb->sqnum;
+ } else {
+ /* We are paranoid and fall back to scanning mode */
+ ubi_err("Fastmap pool PEBs contains damaged PEBs!");
+ ret = err;
+
+ goto out;
+ }
+
+ }
+
+out:
+ ubi_free_vid_hdr(ubi, vh);
+ kfree(ech);
+
+ return ret;
+}
+
+/**
+ * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
+ * @ubi: UBI device object
+ * @fm_raw: the fastmap it self as byte array
+ * @fm_size: size of the fastmap in bytes
+ */
+struct ubi_attach_info *ubi_attach_fastmap(struct ubi_device *ubi, char *fm_raw,
+ size_t fm_size)
+{
+ struct list_head used;
+ struct ubi_ainf_volume *av;
+ struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
+ struct ubi_attach_info *ai;
+
+ struct ubi_fm_sb *fmsb;
+ struct ubi_fm_hdr *fmhdr;
+ struct ubi_fm_scan_pool *fmpl;
+ struct ubi_fm_ec *fmec;
+ struct ubi_fm_volhdr *fmvhdr;
+ struct ubi_fm_eba *fm_eba;
+
+ int i, j;
+ size_t fm_pos = 0;
+ unsigned long long max_sqnum = 0;
+
+ ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
+ if (!ai)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&used);
+ 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->min_ec = UBI_MAX_ERASECOUNTER;
+
+ ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
+ sizeof(struct ubi_ainf_peb),
+ 0, 0, NULL);
+ if (!ai->aeb_slab_cache)
+ goto fail;
+
+ fmsb = (struct ubi_fm_sb *)(fm_raw);
+ ai->max_sqnum = fmsb->sqnum;
+ fm_pos += sizeof(struct ubi_fm_sb);
+ if (fm_pos >= fm_size)
+ goto fail;
+
+ fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fmhdr);
+ if (fm_pos >= fm_size)
+ goto fail;
+
+ if (fmhdr->magic != UBI_FM_HDR_MAGIC)
+ goto fail;
+
+ fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fmpl);
+ if (fm_pos >= fm_size)
+ goto fail;
+ if (fmpl->magic != UBI_FM_POOL_MAGIC)
+ goto fail;
+
+ /* read EC values from free list */
+ for (i = 0; i < be32_to_cpu(fmhdr->nfree); i++) {
+ fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fmec);
+ if (fm_pos >= fm_size)
+ goto fail;
+
+ add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
+ be32_to_cpu(fmec->ec));
+ }
+
+ /* read EC values from used list */
+ for (i = 0; i < be32_to_cpu(fmhdr->nused); i++) {
+ fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fmec);
+ if (fm_pos >= fm_size)
+ goto fail;
+
+ add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
+ be32_to_cpu(fmec->ec));
+ }
+
+ ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
+
+ /* Iterate over all volumes and read their EBA table */
+ for (i = 0; i < be32_to_cpu(fmhdr->nvol); i++) {
+ fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fmvhdr);
+ if (fm_pos >= fm_size)
+ goto fail;
+
+ if (fmvhdr->magic != UBI_FM_VHDR_MAGIC)
+ goto fail;
+
+ av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
+ be32_to_cpu(fmvhdr->used_ebs),
+ be32_to_cpu(fmvhdr->data_pad),
+ fmvhdr->vol_type, be32_to_cpu(fmvhdr->last_eb_bytes));
+
+ if (!av)
+ goto fail;
+
+ ai->vols_found++;
+ if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
+ ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
+
+ fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fm_eba);
+ fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->nused));
+ if (fm_pos >= fm_size)
+ goto fail;
+
+ if (fm_eba->magic != UBI_FM_EBA_MAGIC)
+ goto fail;
+
+ for (j = 0; j < be32_to_cpu(fm_eba->nused); j++) {
+
+ if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
+ continue;
+
+ aeb = NULL;
+ list_for_each_entry(tmp_aeb, &used, u.list) {
+ if (tmp_aeb->pnum == \
+ be32_to_cpu(fm_eba->pnum[j]))
+ aeb = tmp_aeb;
+ }
+
+ /* Corner case, this PEB must be in the pool */
+ if (!aeb)
+ continue;
+
+ aeb->lnum = j;
+
+ if (av->highest_lnum <= aeb->lnum)
+ av->highest_lnum = aeb->lnum;
+
+ assign_aeb_to_av(ai, aeb, av);
+
+ dbg_bld("Inserting PEB:%i (LEB %i) to vol %i",
+ aeb->pnum, aeb->lnum, av->vol_id);
+ }
+ }
+
+ /*
+ * The remainning PEB in the used list are not used.
+ * They lived in the fastmap pool but got never used.
+ */
+ list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
+ list_del(&tmp_aeb->u.list);
+ list_add_tail(&tmp_aeb->u.list, &ai->free);
+ }
+
+ if (scan_pool(ubi, ai, fmpl->pebs, be32_to_cpu(fmpl->size),
+ &max_sqnum) < 0)
+ goto fail;
+
+ if (max_sqnum > ai->max_sqnum)
+ ai->max_sqnum = max_sqnum;
+
+ return ai;
+
+fail:
+ ubi_destroy_ai(ai);
+ return NULL;
+}
+
+/**
+ * ubi_read_fastmap - read the fastmap
+ * @ubi: UBI device object
+ * @cb_sb_pnum: PEB number of the fastmap super block
+ */
+struct ubi_attach_info *ubi_read_fastmap(struct ubi_device *ubi,
+ int cb_sb_pnum)
+{
+ struct ubi_fm_sb *fmsb;
+ struct ubi_vid_hdr *vh;
+ int ret, i, nblocks;
+ char *fm_raw;
+ size_t fm_size;
+ __be32 data_crc;
+ unsigned long long sqnum = 0;
+ struct ubi_attach_info *ai = NULL;
+
+ fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
+ if (!fmsb) {
+ ai = ERR_PTR(-ENOMEM);
+
+ goto out;
+ }
+
+ ret = ubi_io_read(ubi, fmsb, cb_sb_pnum, ubi->leb_start, sizeof(*fmsb));
+ if (ret) {
+ ubi_err("Unable to read fastmap super block");
+ ai = ERR_PTR(ret);
+ kfree(fmsb);
+
+ goto out;
+ }
+
+ if (fmsb->magic != UBI_FM_SB_MAGIC) {
+ ubi_err("Super block magic does not match");
+ ai = ERR_PTR(-EINVAL);
+ kfree(fmsb);
+
+ goto out;
+ }
+
+ if (fmsb->version != UBI_FM_FMT_VERSION) {
+ ubi_err("Unknown fastmap format version!");
+ ai = ERR_PTR(-EINVAL);
+ kfree(fmsb);
+
+ goto out;
+ }
+
+ nblocks = be32_to_cpu(fmsb->nblocks);
+
+ if (nblocks > UBI_FM_MAX_BLOCKS || nblocks < 1) {
+ ubi_err("Number of fastmap blocks is invalid");
+ ai = ERR_PTR(-EINVAL);
+ kfree(fmsb);
+
+ goto out;
+ }
+
+ fm_size = ubi->leb_size * nblocks;
+ /* fm_raw will contain the whole fastmap */
+ fm_raw = vzalloc(fm_size);
+ if (!fm_raw) {
+ ai = ERR_PTR(-ENOMEM);
+ kfree(fmsb);
+
+ goto out;
+ }
+
+ vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vh) {
+ ai = ERR_PTR(-ENOMEM);
+ kfree(fmsb);
+
+ goto free_raw;
+ }
+
+ for (i = 0; i < nblocks; i++) {
+ ret = ubi_io_read_vid_hdr(ubi, be32_to_cpu(fmsb->block_loc[i]),
+ vh, 0);
+ if (ret) {
+ ubi_err("Unable to read fastmap block# %i (PEB: %i)",
+ i, be32_to_cpu(fmsb->block_loc[i]));
+ ai = ERR_PTR(ret);
+ kfree(fmsb);
+
+ goto free_vhdr;
+ }
+
+ if (i == 0) {
+ if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
+ ai = ERR_PTR(-EINVAL);
+ kfree(fmsb);
+
+ goto free_vhdr;
+ }
+ } else {
+ if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
+ goto free_vhdr;
+ kfree(fmsb);
+
+ ai = ERR_PTR(-EINVAL);
+ }
+ }
+
+ if (sqnum < be64_to_cpu(vh->sqnum))
+ sqnum = be64_to_cpu(vh->sqnum);
+
+ ret = ubi_io_read(ubi, fm_raw + (ubi->leb_size * i),
+ be32_to_cpu(fmsb->block_loc[i]),
+ ubi->leb_start, ubi->leb_size);
+
+ if (ret) {
+ ubi_err("Unable to read fastmap block# %i (PEB: %i)",
+ i, be32_to_cpu(fmsb->block_loc[i]));
+ ai = ERR_PTR(ret);
+ kfree(fmsb);
+
+ goto free_vhdr;
+ }
+ }
+
+ kfree(fmsb);
+
+ fmsb = (struct ubi_fm_sb *)fm_raw;
+ data_crc = crc32_be(UBI_CRC32_INIT, fm_raw + sizeof(*fmsb),
+ fm_size - sizeof(*fmsb));
+ if (data_crc != fmsb->data_crc) {
+ ubi_err("Fastmap data CRC is invalid");
+ ai = ERR_PTR(-EINVAL);
+
+ goto free_vhdr;
+ }
+
+ fmsb->sqnum = sqnum;
+
+ ai = ubi_attach_fastmap(ubi, fm_raw, fm_size);
+ if (!ai) {
+ ai = ERR_PTR(-EINVAL);
+
+ goto free_vhdr;
+ }
+
+ /* Store the fastmap position into the ubi_device struct */
+ ubi->fm = kmalloc(sizeof(struct ubi_fastmap), GFP_KERNEL);
+ if (!ubi->fm) {
+ ubi_destroy_ai(ai);
+ ai = ERR_PTR(-ENOMEM);
+
+ goto free_vhdr;
+ }
+
+ ubi->fm->size = fm_size;
+ ubi->fm->used_blocks = nblocks;
+
+ for (i = 0; i < UBI_FM_MAX_BLOCKS; i++) {
+ if (i < nblocks) {
+ ubi->fm->peb[i] = be32_to_cpu(fmsb->block_loc[i]);
+ ubi->fm->ec[i] = be32_to_cpu(fmsb->block_ec[i]);
+ } else {
+ ubi->fm->peb[i] = -1;
+ ubi->fm->ec[i] = 0;
+ }
+ }
+
+free_vhdr:
+ ubi_free_vid_hdr(ubi, vh);
+free_raw:
+ vfree(fm_raw);
+out:
+ return ai;
+}
+
+/**
+ * ubi_find_fastmap - searches the first UBI_FM_MAX_START PEBs for the
+ * fastmap super block.
+ * @ubi: UBI device object
+ */
+int ubi_find_fastmap(struct ubi_device *ubi)
+{
+ int i, ret;
+ int fm_sb = -ENOENT;
+ struct ubi_vid_hdr *vhdr;
+
+ vhdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vhdr)
+ return -ENOMEM;
+
+ for (i = 0; i < UBI_FM_MAX_START; i++) {
+ ret = ubi_io_read_vid_hdr(ubi, i, vhdr, 0);
+ /* ignore read errors */
+ if (ret)
+ continue;
+
+ if (be32_to_cpu(vhdr->vol_id) == UBI_FM_SB_VOLUME_ID) {
+ fm_sb = i;
+ break;
+ }
+ }
+
+ ubi_free_vid_hdr(ubi, vhdr);
+ return fm_sb;
+}
+
+/**
+ * ubi_write_fastmap - writes a fastmap
+ * @ubi: UBI device object
+ * @new_fm: the to be written fastmap
+ */
+static int ubi_write_fastmap(struct ubi_device *ubi,
+ struct ubi_fastmap *new_fm)
+{
+ int ret;
+ size_t fm_pos = 0;
+ char *fm_raw;
+ int i, j;
+
+ struct ubi_fm_sb *fmsb;
+ struct ubi_fm_hdr *fmh;
+ struct ubi_fm_scan_pool *fmpl;
+ struct ubi_fm_ec *fec;
+ struct ubi_fm_volhdr *fvh;
+ struct ubi_fm_eba *feba;
+
+ struct rb_node *node;
+ struct ubi_wl_entry *wl_e;
+ struct ubi_volume *vol;
+
+ struct ubi_vid_hdr *avhdr, *dvhdr;
+
+ int nfree, nused, nvol;
+
+ fm_raw = vzalloc(new_fm->size);
+ if (!fm_raw) {
+ ret = -ENOMEM;
+
+ goto out;
+ }
+
+ avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
+ if (!avhdr) {
+ ret = -ENOMEM;
+
+ goto out_vfree;
+ }
+
+ dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
+ if (!dvhdr) {
+ ret = -ENOMEM;
+
+ goto out_kfree;
+ }
+
+ spin_lock(&ubi->volumes_lock);
+ spin_lock(&ubi->wl_lock);
+
+ fmsb = (struct ubi_fm_sb *)fm_raw;
+ fm_pos += sizeof(*fmsb);
+ ubi_assert(fm_pos <= new_fm->size);
+
+ fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fmh);
+ ubi_assert(fm_pos <= new_fm->size);
+
+ fmsb->magic = UBI_FM_SB_MAGIC;
+ fmsb->version = UBI_FM_FMT_VERSION;
+ fmsb->nblocks = cpu_to_be32(new_fm->used_blocks);
+ /* the max sqnum will be filled in while *reading* the fastmap */
+ fmsb->sqnum = 0;
+
+ fmh->magic = UBI_FM_HDR_MAGIC;
+ nfree = 0;
+ nused = 0;
+ nvol = 0;
+
+ fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fmpl);
+ fmpl->magic = UBI_FM_POOL_MAGIC;
+ fmpl->size = cpu_to_be32(ubi->fm_pool.size);
+
+ for (i = 0; i < ubi->fm_pool.size; i++)
+ fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
+
+ for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
+ wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
+ fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
+
+ fec->pnum = cpu_to_be32(wl_e->pnum);
+ fec->ec = cpu_to_be32(wl_e->ec);
+
+ nfree++;
+ fm_pos += sizeof(*fec);
+ ubi_assert(fm_pos <= new_fm->size);
+ }
+ fmh->nfree = cpu_to_be32(nfree);
+
+ for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
+ wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
+ fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
+
+ fec->pnum = cpu_to_be32(wl_e->pnum);
+ fec->ec = cpu_to_be32(wl_e->ec);
+
+ nused++;
+ fm_pos += sizeof(*fec);
+ ubi_assert(fm_pos <= new_fm->size);
+ }
+ fmh->nused = cpu_to_be32(nused);
+
+ for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
+ vol = ubi->volumes[i];
+
+ if (!vol)
+ continue;
+
+ nvol++;
+
+ fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*fvh);
+ ubi_assert(fm_pos <= new_fm->size);
+
+ fvh->magic = UBI_FM_VHDR_MAGIC;
+ fvh->vol_id = cpu_to_be32(vol->vol_id);
+ fvh->vol_type = vol->vol_type;
+ fvh->used_ebs = cpu_to_be32(vol->used_ebs);
+ fvh->data_pad = cpu_to_be32(vol->data_pad);
+ fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
+
+ ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
+ vol->vol_type == UBI_STATIC_VOLUME);
+
+ feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
+ fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->used_ebs);
+ ubi_assert(fm_pos <= new_fm->size);
+
+ for (j = 0; j < vol->used_ebs; j++)
+ feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
+
+ feba->nused = cpu_to_be32(j);
+ feba->magic = UBI_FM_EBA_MAGIC;
+ }
+ fmh->nvol = cpu_to_be32(nvol);
+
+ avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
+ avhdr->lnum = 0;
+
+ spin_unlock(&ubi->wl_lock);
+ spin_unlock(&ubi->volumes_lock);
+
+ dbg_bld("Writing fastmap SB to PEB %i\n", new_fm->peb[0]);
+ ret = ubi_io_write_vid_hdr(ubi, new_fm->peb[0], avhdr);
+ if (ret) {
+ ubi_err("Unable to write vid_hdr to fastmap SB!\n");
+
+ goto out_kfree;
+ }
+
+ for (i = 0; i < UBI_FM_MAX_BLOCKS; i++) {
+ fmsb->block_loc[i] = cpu_to_be32(new_fm->peb[i]);
+ fmsb->block_ec[i] = cpu_to_be32(new_fm->ec[i]);
+ }
+
+ fmsb->data_crc = 0;
+ fmsb->data_crc = crc32_be(UBI_CRC32_INIT, fm_raw + sizeof(*fmsb),
+ new_fm->size - sizeof(*fmsb));
+
+ for (i = 1; i < new_fm->used_blocks; i++) {
+ dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
+ dvhdr->lnum = cpu_to_be32(i);
+ dbg_bld("Writing fastmap data to PEB %i sqnum %llu\n",
+ new_fm->peb[i], be64_to_cpu(dvhdr->sqnum));
+ ret = ubi_io_write_vid_hdr(ubi, new_fm->peb[i], dvhdr);
+ if (ret) {
+ ubi_err("Unable to write vid_hdr to PEB %i!\n",
+ new_fm->peb[i]);
+
+ goto out_kfree;
+ }
+ }
+
+ for (i = 0; i < new_fm->used_blocks; i++) {
+ ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
+ new_fm->peb[i], ubi->leb_start, ubi->leb_size);
+ if (ret) {
+ ubi_err("Unable to write fastmap to PEB %i!\n",
+ new_fm->peb[i]);
+
+ goto out_kfree;
+ }
+ }
+
+ ubi_assert(new_fm);
+ ubi->fm = new_fm;
+
+ dbg_bld("Fastmap written!");
+
+out_kfree:
+ kfree(avhdr);
+out_vfree:
+ vfree(fm_raw);
+out:
+ return ret;
+}
+
+/**
+ * get_ec - returns the erase counter of a given PEB
+ * @ubi: UBI device object
+ * @pnum: PEB number
+ */
+static int get_ec(struct ubi_device *ubi, int pnum)
+{
+ struct ubi_wl_entry *e;
+
+ e = ubi->lookuptbl[pnum];
+
+ /* can this really happen? */
+ if (!e)
+ return ubi->mean_ec ?: 1;
+ else
+ return e->ec;
+}
+
+/**
+ * ubi_update_fastmap - will be called by UBI if a volume changes or
+ * a fastmap pool becomes full.
+ * @ubi: UBI device object
+ */
+int ubi_update_fastmap(struct ubi_device *ubi)
+{
+ int ret, i;
+ struct ubi_fastmap *new_fm;
+
+ if (ubi->ro_mode)
+ return 0;
+
+ new_fm = kmalloc(sizeof(*new_fm), GFP_KERNEL);
+ if (!new_fm)
+ return -ENOMEM;
+
+ ubi->old_fm = ubi->fm;
+ ubi->fm = NULL;
+
+ if (ubi->old_fm) {
+ spin_lock(&ubi->wl_lock);
+ new_fm->peb[0] = ubi_wl_get_fm_peb(ubi, UBI_FM_MAX_START);
+ spin_unlock(&ubi->wl_lock);
+ /* no fresh early PEB was found, reuse the old one */
+ if (new_fm->peb[0] < 0) {
+ struct ubi_ec_hdr *ec_hdr;
+
+ ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ if (!ec_hdr) {
+ kfree(new_fm);
+ return -ENOMEM;
+ }
+
+ /* we have to erase the block by hand */
+
+ ret = ubi_io_read_ec_hdr(ubi, ubi->old_fm->peb[0],
+ ec_hdr, 0);
+ if (ret) {
+ ubi_err("Unable to read EC header");
+
+ kfree(new_fm);
+ kfree(ec_hdr);
+ return -EINVAL;
+ }
+
+ ret = ubi_io_sync_erase(ubi, ubi->old_fm->peb[0], 0);
+ if (ret < 0) {
+ ubi_err("Unable to erase old SB");
+
+ kfree(new_fm);
+ kfree(ec_hdr);
+ return -EINVAL;
+ }
+
+ ec_hdr->ec += ret;
+ if (ret > UBI_MAX_ERASECOUNTER) {
+ ubi_err("Erase counter overflow!");
+ kfree(new_fm);
+ kfree(ec_hdr);
+ return -EINVAL;
+ }
+
+ ret = ubi_io_write_ec_hdr(ubi, ubi->old_fm->peb[0],
+ ec_hdr);
+ kfree(ec_hdr);
+ if (ret) {
+ ubi_err("Unable to write new EC header");
+ kfree(new_fm);
+ return -EINVAL;
+ }
+
+ new_fm->peb[0] = ubi->old_fm->peb[0];
+ new_fm->ec[0] = ubi->old_fm->ec[0];
+ } else {
+ /* we've got a new early PEB, return the old one */
+ ubi_wl_put_fm_peb(ubi, ubi->old_fm->peb[0], 0);
+ new_fm->ec[0] = get_ec(ubi, new_fm->peb[0]);
+ }
+
+ /* return all other fastmap block to the wl system */
+ for (i = 1; i < UBI_FM_MAX_BLOCKS; i++) {
+ if (ubi->old_fm->peb[i] >= 0)
+ ubi_wl_put_fm_peb(ubi, ubi->old_fm->peb[i], 0);
+ else
+ break;
+ }
+ } else {
+ spin_lock(&ubi->wl_lock);
+ new_fm->peb[0] = ubi_wl_get_fm_peb(ubi, UBI_FM_MAX_START);
+ spin_unlock(&ubi->wl_lock);
+ if (new_fm->peb[0] < 0) {
+ ubi_err("Could not find an early PEB");
+ kfree(new_fm);
+ return -ENOSPC;
+ }
+ new_fm->ec[0] = get_ec(ubi, new_fm->peb[0]);
+ }
+
+ new_fm->size = sizeof(struct ubi_fm_hdr) + \
+ sizeof(struct ubi_fm_scan_pool) + \
+ (ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
+ (sizeof(struct ubi_fm_eba) + \
+ (ubi->peb_count * sizeof(__be32))) + \
+ sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
+ new_fm->size = roundup(new_fm->size, ubi->leb_size);
+
+ new_fm->used_blocks = new_fm->size / ubi->leb_size;
+
+ if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
+ ubi_err("Fastmap too large");
+ kfree(new_fm);
+
+ return -ENOSPC;
+ }
+
+ /* give the wl subsystem a chance to produce some free blocks */
+ cond_resched();
+
+ for (i = 1; i < UBI_FM_MAX_BLOCKS; i++) {
+ if (i < new_fm->used_blocks) {
+ spin_lock(&ubi->wl_lock);
+ new_fm->peb[i] = ubi_wl_get_fm_peb(ubi, INT_MAX);
+ spin_unlock(&ubi->wl_lock);
+ if (new_fm->peb[i] < 0) {
+ ubi_err("Could not get any free erase block");
+
+ while (i--)
+ ubi_wl_put_fm_peb(ubi, new_fm->peb[i],
+ 0);
+
+ kfree(new_fm);
+
+ return -ENOSPC;
+ }
+
+ new_fm->ec[i] = get_ec(ubi, new_fm->peb[i]);
+ } else {
+ new_fm->peb[i] = -1;
+ new_fm->ec[i] = 0;
+ }
+ }
+
+ kfree(ubi->old_fm);
+ ubi->old_fm = NULL;
+
+ return ubi_write_fastmap(ubi, new_fm);
+}
diff --git a/drivers/mtd/ubi/ubi-media.h b/drivers/mtd/ubi/ubi-media.h
index 468ffbc..631a1d0 100644
--- a/drivers/mtd/ubi/ubi-media.h
+++ b/drivers/mtd/ubi/ubi-media.h
@@ -375,4 +375,122 @@ 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
+
+#define UBI_FM_MAX_START 64
+#define UBI_FM_MAX_BLOCKS 32
+#define UBI_FM_MIN_POOL_SIZE 8
+#define UBI_FM_MAX_POOL_SIZE 256
+
+/**
+ * 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
+ * @nblocks: 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 nblocks;
+ __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)
+ * @nfree: number of free PEBs known by this fastmap
+ * @nused: number of used PEBs known by this fastmap
+ * @nvol: number of UBI volumes known by this fastmap
+ */
+struct ubi_fm_hdr {
+ __be32 magic;
+ __be32 nfree;
+ __be32 nused;
+ __be32 nvol;
+ __u8 padding[16];
+} __packed;
+
+/* struct ubi_fm_hdr is followed by 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
+ * @pebs: an array containing the location of all PEBs in this pool
+ */
+struct ubi_fm_scan_pool {
+ __be32 magic;
+ __be32 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
+ * @nused: number of table entries
+ * @pnum: PEB number of LEB (LEB is the index)
+ */
+struct ubi_fm_eba {
+ __be32 magic;
+ __be32 nused;
+ __be32 pnum[0];
+} __packed;
#endif /* !__UBI_MEDIA_H__ */
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 5275632..299a601 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -202,6 +202,39 @@ struct ubi_rename_entry {
struct ubi_volume_desc;

/**
+ * struct ubi_fastmap - in-memory fastmap data structure.
+ * @peb: PEBs used by the current fastamp
+ * @ec: the erase counter of each used PEB
+ * @size: size of the fastmap in bytes
+ * @used_blocks: number of used PEBs
+ */
+struct ubi_fastmap {
+ int peb[UBI_FM_MAX_BLOCKS];
+ unsigned int ec[UBI_FM_MAX_BLOCKS];
+ size_t size;
+ int used_blocks;
+};
+
+/**
+ * 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
* @cdev: character device object to create character device
@@ -336,6 +369,13 @@ struct ubi_wl_entry;
* @ltree: the lock tree
* @alc_mutex: serializes "atomic LEB change" operations
*
+ * @fm: in-memory data structure of the currently used fastmap
+ * @old_fm: in-memory data structure old fastmap.
+ * (only valid while writing a new one)
+ * @fm_pool: in-memory data structure of the fastmap pool
+ * @attached_by_scanning: this UBI device was attached by the old scanning
+ * methold. All fastmap volumes have to be deleted.
+ *
* @used: RB-tree of used physical eraseblocks
* @erroneous: RB-tree of erroneous used physical eraseblocks
* @free: RB-tree of free physical eraseblocks
@@ -427,6 +467,12 @@ struct ubi_device {
struct rb_root ltree;
struct mutex alc_mutex;

+ /* Fastmap stuff */
+ struct ubi_fastmap *fm;
+ struct ubi_fastmap *old_fm;
+ struct ubi_fm_pool fm_pool;
+ bool attached_by_scanning;
+
/* Wear-leveling sub-system's stuff */
struct rb_root used;
struct rb_root erroneous;
@@ -604,7 +650,7 @@ 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,
@@ -661,6 +707,7 @@ 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);

/* wl.c */
int ubi_wl_get_peb(struct ubi_device *ubi);
@@ -670,6 +717,9 @@ 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);
+int ubi_wl_get_fm_peb(struct ubi_device *ubi, int max_pnum);
+int ubi_wl_put_fm_peb(struct ubi_device *ubi, int pnum, int torture);
+int ubi_is_fm_block(struct ubi_device *ubi, int pnum);

/* io.c */
int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
@@ -706,6 +756,15 @@ 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 */
+int ubi_update_fastmap(struct ubi_device *ubi);
+struct ubi_attach_info *ubi_read_fastmap(struct ubi_device *ubi,
+ int fm_sb_pnum);
+int ubi_find_fastmap(struct ubi_device *ubi);

/*
* ubi_rb_for_each_entry - walk an RB-tree.
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index c143e61..c7ab311 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -162,6 +162,25 @@ static int self_check_in_pq(const struct ubi_device *ubi,
struct ubi_wl_entry *e);

/**
+ * ubi_ubi_is_fm_block - returns 1 if a PEB is currently used in a fastmap.
+ * @ubi: UBI device description object
+ * @pnum: the to be checked PEB
+ */
+int ubi_is_fm_block(struct ubi_device *ubi, int pnum)
+{
+ int i;
+
+ if (!ubi->fm)
+ return 0;
+
+ for (i = 0; i < ubi->fm->used_blocks; i++)
+ if (ubi->fm->peb[i] == pnum)
+ return 1;
+
+ return 0;
+}
+
+/**
* wl_tree_add - add a wear-leveling entry to a WL RB-tree.
* @e: the wear-leveling entry to add
* @root: the root of the tree
@@ -367,13 +386,70 @@ static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int diff)
}

/**
- * ubi_wl_get_peb - get a physical eraseblock.
+ * find_early_wl_entry - find wear-leveling entry with a low pnum.
+ * @root: the RB-tree where to look for
+ * @max_pnum: highest possible pnum
+ *
+ * This function looks for a wear leveling entry containing a eb which
+ * is in front of the memory.
+ */
+static struct ubi_wl_entry *find_early_wl_entry(struct rb_root *root,
+ int max_pnum)
+{
+ struct rb_node *p;
+ struct ubi_wl_entry *e, *victim = NULL;
+
+ ubi_rb_for_each_entry(p, e, root, u.rb) {
+ if (e->pnum < max_pnum) {
+ victim = e;
+ max_pnum = e->pnum;
+ }
+ }
+
+ return victim;
+}
+
+/**
+ * ubi_wl_get_fm_peb - find a physical erase block with a given maximal number.
+ * @ubi: UBI device description object
+ * @max_pnum: the highest acceptable erase block number
+ *
+ * The function returns a physical erase block with a given maximal number
+ * and removes it from the wl subsystem.
+ * Must be called with wl_lock held!
+ */
+int ubi_wl_get_fm_peb(struct ubi_device *ubi, int max_pnum)
+{
+ int ret = -ENOSPC;
+ struct ubi_wl_entry *e;
+
+ if (!ubi->free.rb_node) {
+ ubi_err("no free eraseblocks");
+
+ goto out;
+ }
+
+ e = find_early_wl_entry(&ubi->free, max_pnum);
+ if (!e)
+ goto out;
+
+ ret = e->pnum;
+
+ /* remove it from the free list,
+ * the wl subsystem does no longer know this erase block */
+ rb_erase(&e->u.rb, &ubi->free);
+out:
+ return ret;
+}
+
+/**
+ * __ubi_wl_get_peb - get a physical eraseblock.
* @ubi: UBI device description object
*
* This function returns a physical eraseblock in case of success and a
* negative error code in case of failure. Might sleep.
*/
-int ubi_wl_get_peb(struct ubi_device *ubi)
+static int __ubi_wl_get_peb(struct ubi_device *ubi)
{
int err;
struct ubi_wl_entry *e, *first, *last;
@@ -424,6 +500,34 @@ retry:
return e->pnum;
}

+/* ubi_wl_get_peb - works exaclty like __ubi_wl_get_peb but keeps track of
+ * the fastmap pool.
+ */
+int ubi_wl_get_peb(struct ubi_device *ubi)
+{
+ struct ubi_fm_pool *pool = &ubi->fm_pool;
+
+ /* pool contains no free blocks, create a new one
+ * and write a fastmap */
+ if (pool->used == pool->size || !pool->size) {
+ for (pool->size = 0; pool->size < pool->max_size;
+ pool->size++) {
+ pool->pebs[pool->size] = __ubi_wl_get_peb(ubi);
+ if (pool->pebs[pool->size] < 0)
+ break;
+ }
+
+ pool->used = 0;
+ ubi_update_fastmap(ubi);
+ }
+
+ /* we got not a single free PEB */
+ if (!pool->size)
+ return -1;
+
+ return pool->pebs[pool->used++];
+}
+
/**
* prot_queue_del - remove a physical eraseblock from the protection queue.
* @ubi: UBI device description object
@@ -589,6 +693,9 @@ static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
{
struct ubi_work *wl_wrk;

+ ubi_assert(e);
+ ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
+
dbg_wl("schedule erasure of PEB %d, EC %d, torture %d",
e->pnum, e->ec, torture);

@@ -605,6 +712,56 @@ static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
}

/**
+ * ubi_wl_put_fm_peb - returns a PEB used in a fastmap to the wear-leveling
+ * sub-system.
+ *
+ * see: ubi_wl_put_peb()
+ */
+int ubi_wl_put_fm_peb(struct ubi_device *ubi, int pnum, int torture)
+{
+ int i, err = 0;
+ struct ubi_wl_entry *e;
+
+ dbg_wl("PEB %d", pnum);
+ ubi_assert(pnum >= 0);
+ ubi_assert(pnum < ubi->peb_count);
+
+ spin_lock(&ubi->wl_lock);
+ e = ubi->lookuptbl[pnum];
+
+ /* This can happen if we recovered from a fastmap the very
+ * frist time and writing now a new one. In this case the wl system
+ * has never seen any PEB used by the original fastmap.
+ */
+ if (!e) {
+ ubi_assert(ubi->old_fm);
+ e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_ATOMIC);
+ if (!e) {
+ spin_unlock(&ubi->wl_lock);
+ return -ENOMEM;
+ }
+
+ e->pnum = pnum;
+ e->ec = 0;
+ /* use the ec value from the fastmap */
+ for (i = 0; i < UBI_FM_MAX_BLOCKS; i++) {
+ if (pnum == ubi->old_fm->peb[i]) {
+ e->ec = ubi->old_fm->ec[i];
+ break;
+ }
+ }
+ ubi_assert(e->ec);
+ ubi->lookuptbl[pnum] = e;
+ }
+
+ spin_unlock(&ubi->wl_lock);
+
+ err = schedule_erase(ubi, e, torture);
+
+ return err;
+}
+
+/**
* wear_leveling_worker - wear-leveling worker function.
* @ubi: UBI device description object
* @wrk: the work object
@@ -981,6 +1138,8 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,

dbg_wl("erase PEB %d EC %d", pnum, e->ec);

+ ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
+
err = sync_erase(ubi, e, wl_wrk->torture);
if (!err) {
/* Fine, we've erased it successfully */
@@ -1415,6 +1574,7 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)

e->pnum = aeb->pnum;
e->ec = aeb->ec;
+ ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
ubi->lookuptbl[e->pnum] = e;
if (schedule_erase(ubi, e, 0)) {
kmem_cache_free(ubi_wl_entry_slab, e);
@@ -1432,7 +1592,10 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
e->pnum = aeb->pnum;
e->ec = aeb->ec;
ubi_assert(e->ec >= 0);
+ ubi_assert(!ubi_is_fm_block(ubi, e->pnum));
+
wl_tree_add(e, &ubi->free);
+
ubi->lookuptbl[e->pnum] = e;
}

@@ -1447,6 +1610,9 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
e->pnum = aeb->pnum;
e->ec = aeb->ec;
ubi->lookuptbl[e->pnum] = e;
+ if (ubi_is_fm_block(ubi, aeb->pnum))
+ continue;
+
if (!aeb->scrub) {
dbg_wl("add PEB %d EC %d to the used tree",
e->pnum, e->ec);
--
1.7.6.5

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