[RFC][PATCH 6/7] MTD: UBI: Implement checkpointing support

Richard Weinberger
2012-02-14T20:55:08Z

Implements UBI checkpointing support.
It reduces the attaching time from O(N) to O(1).
Checkpoints are written on demand and upon changes of the volume layout.
If the recovery from a checkpoint fails we fall back to scanning mode.

Signed-off-by: Richard Weinberger <rw@linutronix.de>
---
drivers/mtd/ubi/Kconfig | 7 +
drivers/mtd/ubi/Makefile | 1 +
drivers/mtd/ubi/checkpoint.c | 975 ++++++++++++++++++++++++++++++++++++++++++
drivers/mtd/ubi/ubi.h | 6 +
4 files changed, 989 insertions(+), 0 deletions(-)
create mode 100644 drivers/mtd/ubi/checkpoint.c

diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig
index 4dcc752..cae1419 100644
--- a/drivers/mtd/ubi/Kconfig
+++ b/drivers/mtd/ubi/Kconfig
@@ -51,6 +51,13 @@ config MTD_UBI_GLUEBI
volume. This is handy to make MTD-oriented software (like JFFS2)
work on top of UBI. Do not enable this unless you use legacy
software.
+config MTD_UBI_CHECKPOINT
+ bool "UBI checkpointing (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ default n
+ help
+ This option enables UBI checkpointing - it allows attaching UBI
+ devices without scanning the whole MTD device.

config MTD_UBI_DEBUG
bool "UBI debugging"
diff --git a/drivers/mtd/ubi/Makefile b/drivers/mtd/ubi/Makefile
index c9302a5..845312a 100644
--- a/drivers/mtd/ubi/Makefile
+++ b/drivers/mtd/ubi/Makefile
@@ -3,5 +3,6 @@ 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 scan.o
ubi-y += misc.o

+ubi-$(CONFIG_MTD_UBI_CHECKPOINT) += checkpoint.o
ubi-$(CONFIG_MTD_UBI_DEBUG) += debug.o
obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o
diff --git a/drivers/mtd/ubi/checkpoint.c b/drivers/mtd/ubi/checkpoint.c
new file mode 100644
index 0000000..a0aa398
--- /dev/null
+++ b/drivers/mtd/ubi/checkpoint.c
@@ -0,0 +1,975 @@
+/*
+ * Copyright (c) 2012 Linutronix GmbH
+ * Author: Richard Weinberger <richard@nod.at>
+ *
+ * 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"
+
+/* Allocates a new VID header for the checkpoint itself */
+static struct ubi_vid_hdr *new_cp_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);
+
+ /* the checkpoint has be deleted on older kernels */
+ new->compat = UBI_COMPAT_DELETE;
+
+out:
+ return new;
+}
+
+/* Creates and adds a SEB to a given list */
+static int add_seb(struct ubi_scan_info *si, struct list_head *list,
+ int pnum, int ec)
+{
+ struct ubi_scan_leb *seb;
+
+ seb = kmem_cache_alloc(si->scan_leb_slab, GFP_KERNEL);
+ if (!seb)
+ return -ENOMEM;
+
+ seb->pnum = pnum;
+ seb->ec = ec;
+ seb->lnum = -1;
+ seb->scrub = seb->copy_flag = seb->sqnum = 0;
+
+ si->ec_sum += seb->ec;
+ si->ec_count++;
+
+ if (si->max_ec < seb->ec)
+ si->max_ec = seb->ec;
+
+ if (si->min_ec > seb->ec)
+ si->min_ec = seb->ec;
+
+ list_add_tail(&seb->u.list, list);
+
+ return 0;
+}
+
+/* Creates and adds a scan volume into ubi_scan_info */
+static struct ubi_scan_volume *add_vol(struct ubi_scan_info *si, int vol_id,
+ int used_ebs, int data_pad, u8 vol_type,
+ int last_eb_bytes)
+{
+ struct ubi_scan_volume *sv;
+ struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
+
+ while (*p) {
+ parent = *p;
+ sv = rb_entry(parent, struct ubi_scan_volume, rb);
+
+ if (vol_id > sv->vol_id)
+ p = &(*p)->rb_left;
+ else if (vol_id > sv->vol_id)
+ p = &(*p)->rb_right;
+ }
+
+ sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
+ if (!sv)
+ goto out;
+
+ sv->highest_lnum = sv->leb_count = 0;
+ sv->vol_id = vol_id;
+ sv->used_ebs = used_ebs;
+ sv->data_pad = data_pad;
+ sv->last_data_size = last_eb_bytes;
+ sv->compat = 0;
+ sv->vol_type = vol_type;
+ sv->root = RB_ROOT;
+
+ rb_link_node(&sv->rb, parent, p);
+ rb_insert_color(&sv->rb, &si->volumes);
+
+out:
+ return sv;
+}
+
+/* Assigns a SEB to a given scan_volume and removes it from it's original list */
+static void assign_seb_to_sv(struct ubi_scan_info *si, struct ubi_scan_leb *seb,
+ struct ubi_scan_volume *sv)
+{
+ struct ubi_scan_leb *tmp_seb;
+ struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
+
+ p = &sv->root.rb_node;
+ while (*p) {
+ parent = *p;
+
+ tmp_seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
+ if (seb->lnum != tmp_seb->lnum) {
+ if (seb->lnum < tmp_seb->lnum)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+
+ continue;
+ } else
+ break;
+ }
+
+ list_del(&seb->u.list);
+ sv->leb_count++;
+
+ rb_link_node(&seb->u.rb, parent, p);
+ rb_insert_color(&seb->u.rb, &sv->root);
+}
+
+/* Inserts or updates a LEB which was found in the pool */
+static int update_vol(struct ubi_scan_info *si, struct ubi_scan_volume *sv,
+ struct ubi_vid_hdr *new_vh, struct ubi_scan_leb *new_seb)
+{
+ struct rb_node **p = &sv->root.rb_node, *parent = NULL;
+ struct ubi_scan_leb *seb, *victim;
+
+ while (*p) {
+ parent = *p;
+ seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
+
+ if (be32_to_cpu(new_vh->lnum) != seb->lnum) {
+ if (be32_to_cpu(new_vh->lnum) < seb->lnum)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+
+ continue;
+ }
+
+ if (be32_to_cpu(new_vh->sqnum) && seb->sqnum == be32_to_cpu(new_vh->sqnum)) {
+ ubi_err("two LEBs with same sequence number %llu", seb->sqnum);
+ goto fail;
+ }
+
+ if (seb->sqnum > be32_to_cpu(new_vh->sqnum)) {
+ ubi_err("LEB on PEB %i is older than checkpoint?!", seb->pnum);
+
+ goto fail;
+ }
+
+ dbg_bld("Vol %i: Replacing LEB %i's PEB %i with PEB %i\n", sv->vol_id, seb->lnum, seb->pnum, new_seb->pnum);
+
+ victim = kmem_cache_alloc(si->scan_leb_slab, GFP_KERNEL);
+ if (!victim)
+ return -ENOMEM;
+
+ victim->copy_flag = 0;
+ victim->scrub = 0;
+ victim->ec = seb->ec;
+ victim->pnum = seb->pnum;
+ victim->lnum = seb->lnum;
+ list_add_tail(&victim->u.list, &si->erase);
+
+ seb->ec = new_seb->ec;
+ seb->pnum = new_seb->pnum;
+ kmem_cache_free(si->scan_leb_slab, new_seb);
+
+ return 0;
+ }
+
+ /* This LEB is new, let's add it to the volume */
+ dbg_bld("Vol %i (type = %i): SEB %i is new, adding it!\n", sv->vol_type, sv->vol_id, new_seb->lnum);
+
+ if (sv->vol_type == UBI_STATIC_VOLUME) {
+ sv->used_ebs++;
+ sv->leb_count++;
+ }
+
+ rb_link_node(&new_seb->u.rb, parent, p);
+ rb_insert_color(&new_seb->u.rb, &sv->root);
+
+ return 0;
+fail:
+ return -EINVAL;
+}
+
+/* Processes a SEB which was found in the pool */
+static int process_pool_seb(struct ubi_scan_info *si, struct ubi_vid_hdr *new_vh,
+ struct ubi_scan_leb *new_seb)
+{
+ struct ubi_scan_volume *sv, *tmp_sv = NULL;
+ struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
+ int found = 0;
+
+ if (be32_to_cpu(new_vh->vol_id) == UBI_CP_SB_VOLUME_ID ||
+ be32_to_cpu(new_vh->vol_id) == UBI_CP_DATA_VOLUME_ID) {
+ kmem_cache_free(si->scan_leb_slab, new_seb);
+
+ return 0;
+ }
+
+ while (*p) {
+ parent = *p;
+ tmp_sv = rb_entry(parent, struct ubi_scan_volume, rb);
+
+ if (be32_to_cpu(new_vh->vol_id) > tmp_sv->vol_id)
+ p = &(*p)->rb_left;
+ else if (be32_to_cpu(new_vh->vol_id) < tmp_sv->vol_id)
+ p = &(*p)->rb_right;
+ else {
+ found = 1;
+ break;
+ }
+ }
+
+ if (found)
+ sv = tmp_sv;
+ else {
+ ubi_err("Orphaned volume in checkpoint pool!");
+ return -EINVAL;
+ }
+
+ ubi_assert(be32_to_cpu(new_vh->vol_id) == sv->vol_id);
+
+ return update_vol(si, sv, new_vh, new_seb);
+}
+
+static int scan_pool(struct ubi_device *ubi, struct ubi_scan_info *si,
+ int *pebs, int pool_size, unsigned long long *max_sqnum2)
+{
+ struct ubi_vid_hdr *vh;
+ struct ubi_scan_leb *new_seb;
+ int i;
+ int pnum;
+ int err;
+
+ vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vh)
+ return -ENOMEM;
+
+ /*
+ * Now scan all PEB in the pool to find changes which have been made
+ * after the creation of the checkpoint
+ */
+ 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) {
+ dbg_bld("PEB %i in pool is no longer free, scanning it! Vid %i", pnum, be32_to_cpu(vh->vol_id));
+
+ new_seb = kmem_cache_alloc(si->scan_leb_slab, GFP_KERNEL);
+ if (!new_seb) {
+ ubi_free_vid_hdr(ubi, vh);
+ return -ENOMEM;
+ }
+
+ new_seb->ec = -1;
+ new_seb->pnum = pnum;
+ new_seb->lnum = be32_to_cpu(vh->lnum);
+ new_seb->sqnum = be64_to_cpu(vh->sqnum);
+ new_seb->copy_flag = 0;
+ new_seb->scrub = 0;
+
+ err = process_pool_seb(si, vh, new_seb);
+ if (err) {
+ ubi_free_vid_hdr(ubi, vh);
+ return err;
+ }
+
+ if (*max_sqnum2 < new_seb->sqnum)
+ *max_sqnum2 = new_seb->sqnum;
+ } else {
+ /* We are paranoid and fall back to scanning mode */
+ ubi_err("Checkpoint pool PEBs contains damaged PEBs!");
+ ubi_free_vid_hdr(ubi, vh);
+ return err;
+ }
+
+ }
+ ubi_free_vid_hdr(ubi, vh);
+
+ return 0;
+}
+
+/* Creates ubi_scan_info from the checkpoint */
+struct ubi_scan_info *ubi_scan_checkpoint(struct ubi_device *ubi,
+ char *cp_raw,
+ size_t cp_size)
+{
+ struct list_head used;
+ struct ubi_scan_volume *sv;
+ struct ubi_scan_leb *seb, *tmp_seb, *_tmp_seb;
+ struct ubi_scan_info *si;
+ int i, j;
+
+ size_t cp_pos = 0;
+ struct ubi_cp_sb *cpsb;
+ struct ubi_cp_hdr *cphdr;
+ struct ubi_cp_long_pool *cplpl;
+ struct ubi_cp_short_pool *cpspl;
+ struct ubi_cp_unk_pool *cpupl;
+ struct ubi_cp_ec *cpec;
+ struct ubi_cp_volhdr *cpvhdr;
+ struct ubi_cp_eba *cp_eba;
+
+ unsigned long long max_sqnum2 = 0;
+
+ si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
+ if (!si)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&used);
+ INIT_LIST_HEAD(&si->corr);
+ INIT_LIST_HEAD(&si->free);
+ INIT_LIST_HEAD(&si->erase);
+ INIT_LIST_HEAD(&si->alien);
+ si->volumes = RB_ROOT;
+
+ si->scan_leb_slab = kmem_cache_create("ubi_scan_leb_slab",
+ sizeof(struct ubi_scan_leb),
+ 0, 0, NULL);
+ if (!si->scan_leb_slab)
+ goto out_si;
+
+ si->min_ec = UBI_MAX_ERASECOUNTER;
+
+ cpsb = (struct ubi_cp_sb *)(cp_raw);
+ si->max_sqnum = cpsb->sqnum;
+ cp_pos += sizeof(struct ubi_cp_sb);
+ if (cp_pos >= cp_size)
+ goto out_si;
+
+ cphdr = (struct ubi_cp_hdr *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cphdr);
+
+ if (cphdr->magic != UBI_CP_HDR_MAGIC)
+ goto out_si;
+
+ cplpl = (struct ubi_cp_long_pool *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cplpl);
+ if (cplpl->magic != UBI_CP_LPOOL_MAGIC)
+ goto out_si;
+
+ cpspl = (struct ubi_cp_short_pool *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cpspl);
+ if (cpspl->magic != UBI_CP_SPOOL_MAGIC)
+ goto out_si;
+
+ cpupl = (struct ubi_cp_unk_pool *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cpupl);
+ if (cpupl->magic != UBI_CP_UPOOL_MAGIC)
+ goto out_si;
+
+ /* read EC values from free list */
+ for (i = 0; i < be32_to_cpu(cphdr->nfree); i++) {
+ cpec = (struct ubi_cp_ec *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cpec);
+ if (cp_pos >= cp_size)
+ goto out_si;
+
+ add_seb(si, &si->free, be32_to_cpu(cpec->pnum),
+ be32_to_cpu(cpec->ec));
+ }
+
+ /* read EC values from used list */
+ for (i = 0; i < be32_to_cpu(cphdr->nused); i++) {
+ cpec = (struct ubi_cp_ec *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cpec);
+ if (cp_pos >= cp_size) goto out_si;
+
+ add_seb(si, &used, be32_to_cpu(cpec->pnum),
+ be32_to_cpu(cpec->ec));
+ }
+
+ si->mean_ec = div_u64(si->ec_sum, si->ec_count);
+
+ /* Iterate over all volumes and read their EBA table */
+ for (i = 0; i < be32_to_cpu(cphdr->nvol); i++) {
+ cpvhdr = (struct ubi_cp_volhdr *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cpvhdr);
+
+ dbg_bld("Found Volume %i! nused: %i\n", be32_to_cpu(cpvhdr->vol_id), be32_to_cpu(cpvhdr->used_ebs));
+
+ if (cpvhdr->magic != UBI_CP_VHDR_MAGIC)
+ goto out_si;
+
+ sv = add_vol(si, be32_to_cpu(cpvhdr->vol_id),
+ be32_to_cpu(cpvhdr->used_ebs),
+ be32_to_cpu(cpvhdr->data_pad),
+ cpvhdr->vol_type, be32_to_cpu(cpvhdr->last_eb_bytes));
+
+ if (!sv)
+ goto out_si;
+
+ si->vols_found++;
+ if (si->highest_vol_id < be32_to_cpu(cpvhdr->vol_id))
+ si->highest_vol_id = be32_to_cpu(cpvhdr->vol_id);
+
+ for (j = 0; j < be32_to_cpu(cpvhdr->used_ebs); j++) {
+ cp_eba = (struct ubi_cp_eba *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cp_eba);
+ if (cp_pos >= cp_size)
+ goto out_si;
+
+ if ((int)be32_to_cpu(cp_eba->pnum) < 0)
+ continue;
+
+ seb = NULL;
+ list_for_each_entry(tmp_seb, &used, u.list) {
+ if (tmp_seb->pnum == be32_to_cpu(cp_eba->pnum))
+ seb = tmp_seb;
+ }
+
+ /* Not good, a EBA entry points to a PEB which is not in our used list */
+ if (!seb)
+ goto out_si;
+
+ seb->lnum = be32_to_cpu(cp_eba->lnum);
+ assign_seb_to_sv(si, seb, sv);
+
+ dbg_bld("Inserting pnum %i (leb %i) to vol %i", seb->pnum, seb->lnum, sv->vol_id);
+ }
+ }
+
+ /*
+ * The remainning PEB in the used list are not used.
+ * They lived in the checkpoint pool but got never used.
+ */
+ list_for_each_entry_safe(tmp_seb, _tmp_seb, &used, u.list) {
+ list_del(&tmp_seb->u.list);
+ list_add_tail(&tmp_seb->u.list, &si->free);
+ }
+
+ if (scan_pool(ubi, si, cplpl->pebs, be32_to_cpu(cplpl->size), &max_sqnum2) < 0)
+ goto out_si;
+ if (scan_pool(ubi, si, cpspl->pebs, be32_to_cpu(cpspl->size), &max_sqnum2) < 0)
+ goto out_si;
+ if (scan_pool(ubi, si, cpupl->pebs, be32_to_cpu(cpupl->size), &max_sqnum2) < 0)
+ goto out_si;
+
+ if (max_sqnum2 > si->max_sqnum)
+ si->max_sqnum = max_sqnum2;
+
+ return si;
+
+out_si:
+ ubi_scan_destroy_si(si);
+ return NULL;
+}
+
+/* Reads the checkpoint data from it's PEBs */
+struct ubi_scan_info *ubi_read_checkpoint(struct ubi_device *ubi, int cb_sb_pnum)
+{
+ struct ubi_cp_sb *cpsb;
+ struct ubi_vid_hdr *vh;
+ int ret, i, nblocks;
+ char *cp_raw;
+ size_t cp_size;
+ __be32 data_crc;
+ unsigned long long sqnum = 0;
+ struct ubi_scan_info *si = NULL;
+
+ cpsb = kmalloc(sizeof(*cpsb), GFP_KERNEL);
+ if (!cpsb) {
+ si = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ ret = ubi_io_read(ubi, cpsb, cb_sb_pnum, ubi->leb_start, sizeof(*cpsb));
+ if (ret) {
+ ubi_err("Unable to read checkpoint super block");
+ si = ERR_PTR(ret);
+ goto out;
+ }
+
+ if (cpsb->magic != UBI_CP_SB_MAGIC) {
+ ubi_err("Super block magic does not match");
+ si = ERR_PTR(-EINVAL);
+ goto free_sb;
+ }
+
+ if (cpsb->version != UBI_CP_FMT_VERSION) {
+ ubi_err("Unknown checkpoint format version!");
+ si = ERR_PTR(-EINVAL);
+ goto free_sb;
+ }
+
+ nblocks = be32_to_cpu(cpsb->nblocks);
+
+ if (nblocks > UBI_CP_MAX_BLOCKS || nblocks < 1) {
+ ubi_err("Number of checkpoint blocks is invalid");
+ si = ERR_PTR(-EINVAL);
+ goto free_sb;
+ }
+
+ cp_size = ubi->leb_size * nblocks;
+ /* cp_raw will contain the whole checkpoint */
+ cp_raw = vzalloc(cp_size);
+ if (!cp_raw) {
+ si = ERR_PTR(-ENOMEM);
+ goto free_sb;
+ }
+
+ vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vh) {
+ si = ERR_PTR(-ENOMEM);
+ goto free_raw;
+ }
+
+ for (i = 0; i < nblocks; i++) {
+ ret = ubi_io_read_vid_hdr(ubi, be32_to_cpu(cpsb->block_loc[i]), vh, 0);
+ if (ret) {
+ ubi_err("Unable to read checkpoint block# %i (PEB: %i)", i, be32_to_cpu(cpsb->block_loc[i]));
+ si = ERR_PTR(ret);
+ goto free_vhdr;
+ }
+
+ if (i == 0) {
+ if (be32_to_cpu(vh->vol_id) != UBI_CP_SB_VOLUME_ID) {
+ si = ERR_PTR(-EINVAL);
+ goto free_vhdr;
+ }
+ } else {
+ if (be32_to_cpu(vh->vol_id) != UBI_CP_DATA_VOLUME_ID) {
+ goto free_vhdr;
+ si = ERR_PTR(-EINVAL);
+ }
+ }
+
+ if (sqnum < be64_to_cpu(vh->sqnum))
+ sqnum = be64_to_cpu(vh->sqnum);
+
+ ret = ubi_io_read(ubi, cp_raw + (ubi->leb_size * i),
+ be32_to_cpu(cpsb->block_loc[i]), ubi->leb_start,
+ ubi->leb_size);
+
+ if (ret) {
+ ubi_err("Unable to read checkpoint block# %i (PEB: %i)", i, be32_to_cpu(cpsb->block_loc[i]));
+ si = ERR_PTR(ret);
+ goto free_vhdr;
+ }
+ }
+
+
+ cpsb = (struct ubi_cp_sb *)cp_raw;
+ data_crc = crc32_be(UBI_CRC32_INIT, cp_raw + sizeof(*cpsb), cp_size - sizeof(*cpsb));
+ if (data_crc != cpsb->data_crc){
+ ubi_err("Checkpoint data CRC is invalid");
+ si = ERR_PTR(-EINVAL);
+ goto free_vhdr;
+ }
+
+ cpsb->sqnum = sqnum;
+
+ si = ubi_scan_checkpoint(ubi, cp_raw, cp_size);
+ if (!si) {
+ si = ERR_PTR(-EINVAL);
+ goto free_vhdr;
+ }
+
+ /* Store the checkpoint position into the ubi_device struct */
+ ubi->cp = kmalloc(sizeof(struct ubi_checkpoint), GFP_KERNEL);
+ if (!ubi->cp) {
+ si = ERR_PTR(-ENOMEM);
+ ubi_scan_destroy_si(si);
+ goto free_vhdr;
+ }
+
+ ubi->cp->size = cp_size;
+ ubi->cp->used_blocks = nblocks;
+
+ for (i = 0; i < UBI_CP_MAX_BLOCKS; i++) {
+ if (i < nblocks) {
+ ubi->cp->peb[i] = be32_to_cpu(cpsb->block_loc[i]);
+ ubi->cp->ec[i] = be32_to_cpu(cpsb->block_ec[i]);
+ }
+ else {
+ ubi->cp->peb[i] = -1;
+ ubi->cp->ec[i] = 0;
+ }
+ }
+
+free_vhdr:
+ ubi_free_vid_hdr(ubi, vh);
+free_raw:
+ vfree(cp_raw);
+free_sb:
+ kfree(cpsb);
+out:
+ return si;
+}
+
+/* Searches the first UBI_CP_MAX_START PEBs for the checkpoint super block */
+int ubi_find_checkpoint(struct ubi_device *ubi)
+{
+ int i, ret;
+ int cp_sb = -ENOENT;
+ struct ubi_vid_hdr *vhdr;
+
+ vhdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vhdr)
+ return -ENOMEM;
+
+ for (i = 0; i < UBI_CP_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_CP_SB_VOLUME_ID) {
+ cp_sb = i;
+ break;
+ }
+ }
+
+ ubi_free_vid_hdr(ubi, vhdr);
+ return cp_sb;
+}
+
+static int ubi_create_checkpoint(struct ubi_device *ubi,
+ struct ubi_checkpoint *new_cp)
+{
+ int ret;
+ size_t cp_pos = 0;
+ char *cp_raw;
+ int i, j;
+
+ struct ubi_cp_sb *cpsb;
+ struct ubi_cp_hdr *cph;
+ struct ubi_cp_long_pool *cplpl;
+ struct ubi_cp_short_pool *cpspl;
+ struct ubi_cp_unk_pool *cpupl;
+ struct ubi_cp_ec *cec;
+ struct ubi_cp_volhdr *cvh;
+ struct ubi_cp_eba *ceba;
+
+ struct rb_node *node;
+ struct ubi_wl_entry *wl_e;
+ struct ubi_volume *vol;
+
+ struct ubi_vid_hdr *svhdr, *dvhdr;
+
+ int nfree, nused, nvol;
+
+ cp_raw = vzalloc(new_cp->size);
+ if (!cp_raw) {
+ ret = -ENOMEM;
+
+ goto out;
+ }
+
+ svhdr = new_cp_vhdr(ubi, UBI_CP_SB_VOLUME_ID);
+ if (!svhdr) {
+ ret = -ENOMEM;
+
+ goto out_vfree;
+ }
+
+ dvhdr = new_cp_vhdr(ubi, UBI_CP_DATA_VOLUME_ID);
+ if (!dvhdr) {
+ ret = -ENOMEM;
+
+ goto out_kfree;
+ }
+
+ ubi_flush_prot_queue(ubi);
+
+ spin_lock(&ubi->volumes_lock);
+ spin_lock(&ubi->wl_lock);
+
+ cpsb = (struct ubi_cp_sb *)cp_raw;
+ cp_pos += sizeof(*cpsb);
+ ubi_assert(cp_pos <= new_cp->size);
+
+ cph = (struct ubi_cp_hdr *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cph);
+ ubi_assert(cp_pos <= new_cp->size);
+
+ cpsb->magic = UBI_CP_SB_MAGIC;
+ cpsb->version = UBI_CP_FMT_VERSION;
+ cpsb->nblocks = cpu_to_be32(new_cp->used_blocks);
+ /* the max sqnum will be filled in while *reading* the checkpoint */
+ cpsb->sqnum = 0;
+
+ cph->magic = UBI_CP_HDR_MAGIC;
+ nfree = 0;
+ nused = 0;
+ nvol = 0;
+
+ cplpl = (struct ubi_cp_long_pool *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cplpl);
+ cplpl->magic = UBI_CP_LPOOL_MAGIC;
+ cplpl->size = cpu_to_be32(ubi->long_pool.size);
+
+ cpspl = (struct ubi_cp_short_pool *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cpspl);
+ cpspl->magic = UBI_CP_SPOOL_MAGIC;
+ cpspl->size = cpu_to_be32(ubi->short_pool.size);
+
+ cpupl = (struct ubi_cp_unk_pool *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cpupl);
+ cpupl->magic = UBI_CP_UPOOL_MAGIC;
+ cpupl->size = cpu_to_be32(ubi->unk_pool.size);
+
+ for (i = 0; i < ubi->long_pool.size; i++)
+ cplpl->pebs[i] = cpu_to_be32(ubi->long_pool.pebs[i]);
+
+ for (i = 0; i < ubi->short_pool.size; i++)
+ cpspl->pebs[i] = cpu_to_be32(ubi->short_pool.pebs[i]);
+
+ for (i = 0; i < ubi->unk_pool.size; i++)
+ cpupl->pebs[i] = cpu_to_be32(ubi->unk_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);
+ cec = (struct ubi_cp_ec *)(cp_raw + cp_pos);
+
+ cec->pnum = cpu_to_be32(wl_e->pnum);
+ cec->ec = cpu_to_be32(wl_e->ec);
+
+ nfree++;
+ cp_pos += sizeof(*cec);
+ ubi_assert(cp_pos <= new_cp->size);
+ }
+ cph->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);
+ cec = (struct ubi_cp_ec *)(cp_raw + cp_pos);
+
+ cec->pnum = cpu_to_be32(wl_e->pnum);
+ cec->ec = cpu_to_be32(wl_e->ec);
+
+ nused++;
+ cp_pos += sizeof(*cec);
+ ubi_assert(cp_pos <= new_cp->size);
+ }
+ cph->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++;
+
+ cvh = (struct ubi_cp_volhdr *)(cp_raw + cp_pos);
+ cp_pos += sizeof(*cvh);
+ ubi_assert(cp_pos <= new_cp->size);
+
+ cvh->magic = UBI_CP_VHDR_MAGIC;
+ cvh->vol_id = cpu_to_be32(vol->vol_id);
+ cvh->vol_type = vol->vol_type;
+ cvh->used_ebs = cpu_to_be32(vol->used_ebs);
+ cvh->data_pad = cpu_to_be32(vol->data_pad);
+ cvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
+
+ ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME || vol->vol_type == UBI_STATIC_VOLUME);
+
+ for (j = 0; j < vol->used_ebs; j++) {
+ ceba = (struct ubi_cp_eba *)(cp_raw + cp_pos);
+
+ ceba->lnum = cpu_to_be32(j);
+ ceba->pnum = cpu_to_be32(vol->eba_tbl[j]);
+
+ cp_pos += sizeof(*ceba);
+ ubi_assert(cp_pos <= new_cp->size);
+ }
+ }
+ cph->nvol = cpu_to_be32(nvol);
+
+ svhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
+ svhdr->lnum = 0;
+
+ spin_unlock(&ubi->wl_lock);
+ spin_unlock(&ubi->volumes_lock);
+
+ dbg_bld("Writing checkpoint SB to PEB %i\n", new_cp->peb[0]);
+ ret = ubi_io_write_vid_hdr(ubi, new_cp->peb[0], svhdr);
+ if (ret) {
+ ubi_err("Unable to write vid_hdr to checkpoint SB!\n");
+ goto out_kfree;
+ }
+
+ for (i = 0; i < UBI_CP_MAX_BLOCKS; i++) {
+ cpsb->block_loc[i] = cpu_to_be32(new_cp->peb[i]);
+ cpsb->block_ec[i] = cpu_to_be32(new_cp->ec[i]);
+ }
+
+ cpsb->data_crc = 0;
+ cpsb->data_crc = crc32_be(UBI_CRC32_INIT, cp_raw + sizeof(*cpsb), new_cp->size - sizeof(*cpsb));
+
+ for (i = 1; i < new_cp->used_blocks; i++) {
+ dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
+ dvhdr->lnum = cpu_to_be32(i);
+ dbg_bld("Writing checkpoint data to PEB %i sqnum %llu\n", new_cp->peb[i], be64_to_cpu(dvhdr->sqnum));
+ ret = ubi_io_write_vid_hdr(ubi, new_cp->peb[i], dvhdr);
+ if (ret) {
+ ubi_err("Unable to write vid_hdr to PEB %i!\n", new_cp->peb[i]);
+ goto out_kfree;
+ }
+ }
+
+ for (i = 0; i < new_cp->used_blocks; i++) {
+ ret = ubi_io_write(ubi, cp_raw + (i * ubi->leb_size), new_cp->peb[i], ubi->leb_start, ubi->leb_size);
+ if (ret) {
+ ubi_err("Unable to write checkpoint to PEB %i!\n", new_cp->peb[i]);
+ goto out_kfree;
+ }
+ }
+
+ ubi->cp = new_cp;
+
+ ubi_msg("Checkpoint written!");
+
+out_kfree:
+ kfree(svhdr);
+out_vfree:
+ vfree(cp_raw);
+out:
+ return ret;
+}
+
+/* Will be called by UBI upon volume creation/deletion/etc.. */
+int ubi_update_checkpoint(struct ubi_device *ubi)
+{
+ int ret, i;
+ struct ubi_checkpoint *new_cp, *old_cp;
+ struct ubi_wl_entry *e;
+
+ if (ubi->ro_mode)
+ return 0;
+
+ new_cp = kmalloc(sizeof(*new_cp), GFP_KERNEL);
+ if (!new_cp)
+ return -ENOMEM;
+
+ old_cp = ubi->cp;
+ ubi->cp = NULL;
+
+ if (old_cp) {
+ new_cp->peb[0] = ubi_wl_get_cp_peb(ubi, UBI_CP_MAX_START);
+ /* no fresh early PEB was found, reuse the old one */
+ if (new_cp->peb[0] < 0) {
+ struct ubi_ec_hdr *ec_hdr;
+
+ ec_hdr = kmalloc(sizeof(*ec_hdr), GFP_KERNEL);
+ if (!ec_hdr) {
+ kfree(new_cp);
+ return -ENOMEM;
+ }
+
+ /* we have to erase the block by hand */
+ ret = ubi_io_read_ec_hdr(ubi, old_cp->peb[0], ec_hdr, 0);
+ if (!ret) {
+ ubi_err("Unable to read EC header");
+
+ kfree(new_cp);
+ kfree(ec_hdr);
+ return -EINVAL;
+ }
+
+ ret = ubi_io_sync_erase(ubi, new_cp->peb[0], 0);
+ if (ret < 0) {
+ ubi_err("Unable to erase old SB");
+
+ kfree(new_cp);
+ kfree(ec_hdr);
+ return -EINVAL;
+ }
+
+ ec_hdr->ec += ret;
+ if (ret > UBI_MAX_ERASECOUNTER) {
+ ubi_err("Erase counter overflow!");
+ kfree(new_cp);
+ kfree(ec_hdr);
+ return -EINVAL;
+ }
+
+ ret = ubi_io_write_ec_hdr(ubi, old_cp->peb[0], ec_hdr);
+ kfree(ec_hdr);
+ if (ret) {
+ ubi_err("Unable to write new EC header");
+ kfree(new_cp);
+ return -EINVAL;
+ }
+
+ new_cp->peb[0] = old_cp->peb[0];
+ }
+ else
+ /* we've got a new early PEB, return the old one */
+ ubi_wl_put_cp_peb(ubi, old_cp->peb[0], 0);
+
+ /* return all other checkpoint block to the wl system */
+ for (i = 1; i < UBI_CP_MAX_BLOCKS; i++) {
+ if (old_cp->peb[i] >= 0)
+ ubi_wl_put_cp_peb(ubi, old_cp->peb[i], 0);
+ else
+ break;
+ }
+ } else {
+ new_cp->peb[0] = ubi_wl_get_cp_peb(ubi, UBI_CP_MAX_START);
+ if (new_cp->peb[0] < 0) {
+ ubi_err("Could not find an early PEB");
+ kfree(new_cp);
+ return -ENOSPC;
+ }
+ }
+
+ new_cp->size = sizeof(struct ubi_cp_hdr) + \
+ sizeof(struct ubi_cp_long_pool) + \
+ sizeof(struct ubi_cp_short_pool) + \
+ sizeof(struct ubi_cp_unk_pool) + \
+ ubi->peb_count * (sizeof(struct ubi_cp_ec) + \
+ sizeof(struct ubi_cp_eba)) + \
+ sizeof(struct ubi_cp_volhdr) * UBI_MAX_VOLUMES;
+ new_cp->size = roundup(new_cp->size, ubi->leb_size);
+
+ new_cp->used_blocks = new_cp->size / ubi->leb_size;
+
+ if (new_cp->used_blocks > UBI_CP_MAX_BLOCKS) {
+ ubi_err("Checkpoint too large");
+ kfree(new_cp);
+
+ return -ENOSPC;
+ }
+
+ /* give the wl subsystem a chance to produce some free blocks */
+ cond_resched();
+
+ for (i = 1; i < UBI_CP_MAX_BLOCKS; i++) {
+ if (i < new_cp->used_blocks) {
+ new_cp->peb[i] = ubi_wl_get_cp_peb(ubi, INT_MAX);
+ if (new_cp->peb[i] < 0) {
+ ubi_err("Could not get any free erase block");
+
+ while (i--)
+ ubi_wl_put_cp_peb(ubi, new_cp->peb[i], 0);
+
+ kfree(new_cp);
+
+ return -ENOSPC;
+ }
+ e = ubi->lookuptbl[new_cp->peb[i]];
+ ubi_assert(e);
+ new_cp->ec[i] = e->ec;
+ } else {
+ new_cp->peb[i] = -1;
+ new_cp->ec[i] = 0;
+ }
+ }
+
+ kfree(old_cp);
+
+ return ubi_create_checkpoint(ubi, new_cp);
+}
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 4e8e8d2..a5aa2b1 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -608,6 +608,12 @@ 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);

+/* checkpoint.c */
+int ubi_update_checkpoint(struct ubi_device *ubi);
+struct ubi_scan_info *ubi_read_checkpoint(struct ubi_device *ubi, int cb_sb_pnum);
+int ubi_update_checkpoint(struct ubi_device *ubi);
+int ubi_find_checkpoint(struct ubi_device *ubi);
+
/*
* ubi_rb_for_each_entry - walk an RB-tree.
* @rb: a pointer to type 'struct rb_node' to use as a loop counter
--
1.7.7