obj-$(CONFIG_MTD_UBI) += ubi.o
-ubi-y += vtbl.o vmt.o upd.o build.o cdev.o kapi.o eba.o io.o wl.o scan.o
+ubi-y += vtbl.o vmt.o upd.o build.o cdev.o kapi.o eba.o io.o wl.o attach.o
ubi-y += misc.o debug.o
obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o
--- /dev/null
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * 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, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * UBI attaching sub-system.
+ *
+ * This sub-system is responsible for attaching MTD devices and it also
+ * implements flash media scanning.
+ *
+ * The attaching information is represented by a &struct ubi_attach_info'
+ * object. Information about volumes is represented by &struct ubi_ainf_volume
+ * objects which are kept in volume RB-tree with root at the @volumes field.
+ * The RB-tree is indexed by the volume ID.
+ *
+ * Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These
+ * objects are kept in per-volume RB-trees with the root at the corresponding
+ * &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of
+ * per-volume objects and each of these objects is the root of RB-tree of
+ * per-LEB objects.
+ *
+ * Corrupted physical eraseblocks are put to the @corr list, free physical
+ * eraseblocks are put to the @free list and the physical eraseblock to be
+ * erased are put to the @erase list.
+ *
+ * About corruptions
+ * ~~~~~~~~~~~~~~~~~
+ *
+ * UBI protects EC and VID headers with CRC-32 checksums, so it can detect
+ * whether the headers are corrupted or not. Sometimes UBI also protects the
+ * data with CRC-32, e.g., when it executes the atomic LEB change operation, or
+ * when it moves the contents of a PEB for wear-leveling purposes.
+ *
+ * UBI tries to distinguish between 2 types of corruptions.
+ *
+ * 1. Corruptions caused by power cuts. These are expected corruptions and UBI
+ * tries to handle them gracefully, without printing too many warnings and
+ * error messages. The idea is that we do not lose important data in these
+ * cases - we may lose only the data which were being written to the media just
+ * before the power cut happened, and the upper layers (e.g., UBIFS) are
+ * supposed to handle such data losses (e.g., by using the FS journal).
+ *
+ * When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like
+ * the reason is a power cut, UBI puts this PEB to the @erase list, and all
+ * PEBs in the @erase list are scheduled for erasure later.
+ *
+ * 2. Unexpected corruptions which are not caused by power cuts. During
+ * attaching, such PEBs are put to the @corr list and UBI preserves them.
+ * Obviously, this lessens the amount of available PEBs, and if at some point
+ * UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs
+ * about such PEBs every time the MTD device is attached.
+ *
+ * However, it is difficult to reliably distinguish between these types of
+ * corruptions and UBI's strategy is as follows (in case of attaching by
+ * scanning). UBI assumes corruption type 2 if the VID header is corrupted and
+ * the data area does not contain all 0xFFs, and there were no bit-flips or
+ * integrity errors (e.g., ECC errors in case of NAND) while reading the data
+ * area. Otherwise UBI assumes corruption type 1. So the decision criteria
+ * are as follows.
+ * o If the data area contains only 0xFFs, there are no data, and it is safe
+ * to just erase this PEB - this is corruption type 1.
+ * o If the data area has bit-flips or data integrity errors (ECC errors on
+ * NAND), it is probably a PEB which was being erased when power cut
+ * happened, so this is corruption type 1. However, this is just a guess,
+ * which might be wrong.
+ * o Otherwise this it corruption type 2.
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/crc32.h>
+#include <linux/math64.h>
+#include <linux/random.h>
+#include "ubi.h"
+
+static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);
+
+/* Temporary variables used during scanning */
+static struct ubi_ec_hdr *ech;
+static struct ubi_vid_hdr *vidh;
+
+/**
+ * add_to_list - add physical eraseblock to a list.
+ * @ai: attaching information
+ * @pnum: physical eraseblock number to add
+ * @ec: erase counter of the physical eraseblock
+ * @to_head: if not zero, add to the head of the list
+ * @list: the list to add to
+ *
+ * This function allocates a 'struct ubi_ainf_peb' object for physical
+ * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.
+ * If @to_head is not zero, PEB will be added to the head of the list, which
+ * basically means it will be processed first later. E.g., we add corrupted
+ * PEBs (corrupted due to power cuts) to the head of the erase list to make
+ * sure we erase them first and get rid of corruptions ASAP. This function
+ * returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int add_to_list(struct ubi_attach_info *ai, int pnum, int ec,
+ int to_head, struct list_head *list)
+{
+ struct ubi_ainf_peb *aeb;
+
+ if (list == &ai->free) {
+ dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
+ } else if (list == &ai->erase) {
+ dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
+ } else if (list == &ai->alien) {
+ dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
+ ai->alien_peb_count += 1;
+ } else
+ BUG();
+
+ aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
+ if (!aeb)
+ return -ENOMEM;
+
+ aeb->pnum = pnum;
+ aeb->ec = ec;
+ if (to_head)
+ list_add(&aeb->u.list, list);
+ else
+ list_add_tail(&aeb->u.list, list);
+ return 0;
+}
+
+/**
+ * add_corrupted - add a corrupted physical eraseblock.
+ * @ai: attaching information
+ * @pnum: physical eraseblock number to add
+ * @ec: erase counter of the physical eraseblock
+ *
+ * This function allocates a 'struct ubi_ainf_peb' object for a corrupted
+ * physical eraseblock @pnum and adds it to the 'corr' list. The corruption
+ * was presumably not caused by a power cut. Returns zero in case of success
+ * and a negative error code in case of failure.
+ */
+static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
+{
+ struct ubi_ainf_peb *aeb;
+
+ dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
+
+ aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
+ if (!aeb)
+ return -ENOMEM;
+
+ ai->corr_peb_count += 1;
+ aeb->pnum = pnum;
+ aeb->ec = ec;
+ list_add(&aeb->u.list, &ai->corr);
+ return 0;
+}
+
+/**
+ * validate_vid_hdr - check volume identifier header.
+ * @vid_hdr: the volume identifier header to check
+ * @av: information about the volume this logical eraseblock belongs to
+ * @pnum: physical eraseblock number the VID header came from
+ *
+ * This function checks that data stored in @vid_hdr is consistent. Returns
+ * non-zero if an inconsistency was found and zero if not.
+ *
+ * Note, UBI does sanity check of everything it reads from the flash media.
+ * Most of the checks are done in the I/O sub-system. Here we check that the
+ * information in the VID header is consistent to the information in other VID
+ * headers of the same volume.
+ */
+static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
+ const struct ubi_ainf_volume *av, int pnum)
+{
+ int vol_type = vid_hdr->vol_type;
+ int vol_id = be32_to_cpu(vid_hdr->vol_id);
+ int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
+ int data_pad = be32_to_cpu(vid_hdr->data_pad);
+
+ if (av->leb_count != 0) {
+ int av_vol_type;
+
+ /*
+ * This is not the first logical eraseblock belonging to this
+ * volume. Ensure that the data in its VID header is consistent
+ * to the data in previous logical eraseblock headers.
+ */
+
+ if (vol_id != av->vol_id) {
+ ubi_err("inconsistent vol_id");
+ goto bad;
+ }
+
+ if (av->vol_type == UBI_STATIC_VOLUME)
+ av_vol_type = UBI_VID_STATIC;
+ else
+ av_vol_type = UBI_VID_DYNAMIC;
+
+ if (vol_type != av_vol_type) {
+ ubi_err("inconsistent vol_type");
+ goto bad;
+ }
+
+ if (used_ebs != av->used_ebs) {
+ ubi_err("inconsistent used_ebs");
+ goto bad;
+ }
+
+ if (data_pad != av->data_pad) {
+ ubi_err("inconsistent data_pad");
+ goto bad;
+ }
+ }
+
+ return 0;
+
+bad:
+ ubi_err("inconsistent VID header at PEB %d", pnum);
+ ubi_dump_vid_hdr(vid_hdr);
+ ubi_dump_av(av);
+ return -EINVAL;
+}
+
+/**
+ * add_volume - add volume to the attaching information.
+ * @ai: attaching information
+ * @vol_id: ID of the volume to add
+ * @pnum: physical eraseblock number
+ * @vid_hdr: volume identifier header
+ *
+ * If the volume corresponding to the @vid_hdr logical eraseblock is already
+ * present in the attaching information, this function does nothing. Otherwise
+ * it adds corresponding volume to the attaching information. Returns a pointer
+ * to the allocated "av" object in case of success and a negative error code in
+ * case of failure.
+ */
+static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
+ int vol_id, int pnum,
+ const struct ubi_vid_hdr *vid_hdr)
+{
+ struct ubi_ainf_volume *av;
+ struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
+
+ ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
+
+ /* Walk the volume RB-tree to look if this volume is already present */
+ while (*p) {
+ parent = *p;
+ av = rb_entry(parent, struct ubi_ainf_volume, rb);
+
+ if (vol_id == av->vol_id)
+ return av;
+
+ if (vol_id > av->vol_id)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+
+ /* The volume is absent - add it */
+ av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
+ if (!av)
+ return ERR_PTR(-ENOMEM);
+
+ av->highest_lnum = av->leb_count = 0;
+ av->vol_id = vol_id;
+ av->root = RB_ROOT;
+ av->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
+ av->data_pad = be32_to_cpu(vid_hdr->data_pad);
+ av->compat = vid_hdr->compat;
+ av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
+ : UBI_STATIC_VOLUME;
+ if (vol_id > ai->highest_vol_id)
+ ai->highest_vol_id = vol_id;
+
+ rb_link_node(&av->rb, parent, p);
+ rb_insert_color(&av->rb, &ai->volumes);
+ ai->vols_found += 1;
+ dbg_bld("added volume %d", vol_id);
+ return av;
+}
+
+/**
+ * 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
+ * compare
+ * @vid_hdr: volume identifier header of the second logical eraseblock
+ *
+ * This function compares 2 copies of a LEB and informs which one is newer. In
+ * case of success this function returns a positive value, in case of failure, a
+ * negative error code is returned. The success return codes use the following
+ * bits:
+ * o bit 0 is cleared: the first PEB (described by @aeb) is newer than the
+ * second PEB (described by @pnum and @vid_hdr);
+ * o bit 0 is set: the second PEB is newer;
+ * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
+ * o bit 1 is set: bit-flips were detected in the newer LEB;
+ * 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 pnum, const struct ubi_vid_hdr *vid_hdr)
+{
+ void *buf;
+ int len, err, second_is_newer, bitflips = 0, corrupted = 0;
+ uint32_t data_crc, crc;
+ struct ubi_vid_hdr *vh = NULL;
+ unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
+
+ if (sqnum2 == aeb->sqnum) {
+ /*
+ * This must be a really ancient UBI image which has been
+ * created before sequence numbers support has been added. At
+ * that times we used 32-bit LEB versions stored in logical
+ * eraseblocks. That was before UBI got into mainline. We do not
+ * support these images anymore. Well, those images still work,
+ * but only if no unclean reboots happened.
+ */
+ ubi_err("unsupported on-flash UBI format\n");
+ return -EINVAL;
+ }
+
+ /* Obviously the LEB with lower sequence counter is older */
+ second_is_newer = (sqnum2 > aeb->sqnum);
+
+ /*
+ * Now we know which copy is newer. If the copy flag of the PEB with
+ * newer version is not set, then we just return, otherwise we have to
+ * check data CRC. For the second PEB we already have the VID header,
+ * for the first one - we'll need to re-read it from flash.
+ *
+ * Note: this may be optimized so that we wouldn't read twice.
+ */
+
+ if (second_is_newer) {
+ if (!vid_hdr->copy_flag) {
+ /* It is not a copy, so it is newer */
+ dbg_bld("second PEB %d is newer, copy_flag is unset",
+ pnum);
+ return 1;
+ }
+ } else {
+ if (!aeb->copy_flag) {
+ /* It is not a copy, so it is newer */
+ dbg_bld("first PEB %d is newer, copy_flag is unset",
+ pnum);
+ return bitflips << 1;
+ }
+
+ vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vh)
+ return -ENOMEM;
+
+ pnum = aeb->pnum;
+ err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
+ if (err) {
+ if (err == UBI_IO_BITFLIPS)
+ bitflips = 1;
+ else {
+ ubi_err("VID of PEB %d header is bad, but it "
+ "was OK earlier, err %d", pnum, err);
+ if (err > 0)
+ err = -EIO;
+
+ goto out_free_vidh;
+ }
+ }
+
+ vid_hdr = vh;
+ }
+
+ /* Read the data of the copy and check the CRC */
+
+ len = be32_to_cpu(vid_hdr->data_size);
+ buf = vmalloc(len);
+ if (!buf) {
+ err = -ENOMEM;
+ goto out_free_vidh;
+ }
+
+ err = ubi_io_read_data(ubi, buf, pnum, 0, len);
+ if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
+ goto out_free_buf;
+
+ data_crc = be32_to_cpu(vid_hdr->data_crc);
+ crc = crc32(UBI_CRC32_INIT, buf, len);
+ if (crc != data_crc) {
+ dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
+ pnum, crc, data_crc);
+ corrupted = 1;
+ bitflips = 0;
+ second_is_newer = !second_is_newer;
+ } else {
+ dbg_bld("PEB %d CRC is OK", pnum);
+ bitflips = !!err;
+ }
+
+ vfree(buf);
+ ubi_free_vid_hdr(ubi, vh);
+
+ if (second_is_newer)
+ dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
+ else
+ dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
+
+ return second_is_newer | (bitflips << 1) | (corrupted << 2);
+
+out_free_buf:
+ vfree(buf);
+out_free_vidh:
+ ubi_free_vid_hdr(ubi, vh);
+ return err;
+}
+
+/**
+ * ubi_add_to_av - add used physical eraseblock to the attaching information.
+ * @ubi: UBI device description object
+ * @ai: attaching information
+ * @pnum: the physical eraseblock number
+ * @ec: erase counter
+ * @vid_hdr: the volume identifier header
+ * @bitflips: if bit-flips were detected when this physical eraseblock was read
+ *
+ * This function adds information about a used physical eraseblock to the
+ * 'used' tree of the corresponding volume. The function is rather complex
+ * because it has to handle cases when this is not the first physical
+ * eraseblock belonging to the same logical eraseblock, and the newer one has
+ * to be picked, while the older one has to be dropped. This function returns
+ * zero in case of success and a negative error code in case of failure.
+ */
+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)
+{
+ int err, vol_id, lnum;
+ unsigned long long sqnum;
+ struct ubi_ainf_volume *av;
+ struct ubi_ainf_peb *aeb;
+ struct rb_node **p, *parent = NULL;
+
+ vol_id = be32_to_cpu(vid_hdr->vol_id);
+ lnum = be32_to_cpu(vid_hdr->lnum);
+ sqnum = be64_to_cpu(vid_hdr->sqnum);
+
+ dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
+ pnum, vol_id, lnum, ec, sqnum, bitflips);
+
+ av = add_volume(ai, vol_id, pnum, vid_hdr);
+ if (IS_ERR(av))
+ return PTR_ERR(av);
+
+ if (ai->max_sqnum < sqnum)
+ ai->max_sqnum = sqnum;
+
+ /*
+ * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
+ * if this is the first instance of this logical eraseblock or not.
+ */
+ p = &av->root.rb_node;
+ while (*p) {
+ int cmp_res;
+
+ parent = *p;
+ aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
+ if (lnum != aeb->lnum) {
+ if (lnum < aeb->lnum)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ continue;
+ }
+
+ /*
+ * There is already a physical eraseblock describing the same
+ * logical eraseblock present.
+ */
+
+ dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",
+ aeb->pnum, aeb->sqnum, aeb->ec);
+
+ /*
+ * Make sure that the logical eraseblocks have different
+ * sequence numbers. Otherwise the image is bad.
+ *
+ * However, if the sequence number is zero, we assume it must
+ * be an ancient UBI image from the era when UBI did not have
+ * 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
+ * images, but refuse attaching old images with duplicated
+ * logical eraseblocks because there was an unclean reboot.
+ */
+ if (aeb->sqnum == sqnum && sqnum != 0) {
+ ubi_err("two LEBs with same sequence number %llu",
+ sqnum);
+ ubi_dump_aeb(aeb, 0);
+ ubi_dump_vid_hdr(vid_hdr);
+ return -EINVAL;
+ }
+
+ /*
+ * Now we have to drop the older one and preserve the newer
+ * one.
+ */
+ cmp_res = compare_lebs(ubi, aeb, pnum, vid_hdr);
+ if (cmp_res < 0)
+ return cmp_res;
+
+ if (cmp_res & 1) {
+ /*
+ * This logical eraseblock is newer than the one
+ * found earlier.
+ */
+ err = validate_vid_hdr(vid_hdr, av, pnum);
+ if (err)
+ return err;
+
+ err = add_to_list(ai, aeb->pnum, aeb->ec, cmp_res & 4,
+ &ai->erase);
+ if (err)
+ return err;
+
+ aeb->ec = ec;
+ aeb->pnum = pnum;
+ aeb->scrub = ((cmp_res & 2) || bitflips);
+ aeb->copy_flag = vid_hdr->copy_flag;
+ aeb->sqnum = sqnum;
+
+ if (av->highest_lnum == lnum)
+ av->last_data_size =
+ be32_to_cpu(vid_hdr->data_size);
+
+ return 0;
+ } else {
+ /*
+ * This logical eraseblock is older than the one found
+ * previously.
+ */
+ return add_to_list(ai, pnum, ec, cmp_res & 4,
+ &ai->erase);
+ }
+ }
+
+ /*
+ * We've met this logical eraseblock for the first time, add it to the
+ * attaching information.
+ */
+
+ err = validate_vid_hdr(vid_hdr, av, pnum);
+ if (err)
+ return err;
+
+ aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
+ if (!aeb)
+ return -ENOMEM;
+
+ aeb->ec = ec;
+ aeb->pnum = pnum;
+ aeb->lnum = lnum;
+ aeb->scrub = bitflips;
+ aeb->copy_flag = vid_hdr->copy_flag;
+ aeb->sqnum = sqnum;
+
+ if (av->highest_lnum <= lnum) {
+ av->highest_lnum = lnum;
+ av->last_data_size = be32_to_cpu(vid_hdr->data_size);
+ }
+
+ av->leb_count += 1;
+ rb_link_node(&aeb->u.rb, parent, p);
+ rb_insert_color(&aeb->u.rb, &av->root);
+ return 0;
+}
+
+/**
+ * ubi_find_av - find volume in the attaching information.
+ * @ai: attaching information
+ * @vol_id: the requested volume ID
+ *
+ * This function returns a pointer to the volume description or %NULL if there
+ * are no data about this volume in the attaching information.
+ */
+struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
+ int vol_id)
+{
+ struct ubi_ainf_volume *av;
+ struct rb_node *p = ai->volumes.rb_node;
+
+ while (p) {
+ av = rb_entry(p, struct ubi_ainf_volume, rb);
+
+ if (vol_id == av->vol_id)
+ return av;
+
+ if (vol_id > av->vol_id)
+ p = p->rb_left;
+ else
+ p = p->rb_right;
+ }
+
+ return NULL;
+}
+
+/**
+ * ubi_remove_av - delete attaching information about a volume.
+ * @ai: attaching information
+ * @av: the volume attaching information to delete
+ */
+void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
+{
+ struct rb_node *rb;
+ struct ubi_ainf_peb *aeb;
+
+ dbg_bld("remove attaching information about volume %d", av->vol_id);
+
+ while ((rb = rb_first(&av->root))) {
+ aeb = rb_entry(rb, struct ubi_ainf_peb, u.rb);
+ rb_erase(&aeb->u.rb, &av->root);
+ list_add_tail(&aeb->u.list, &ai->erase);
+ }
+
+ rb_erase(&av->rb, &ai->volumes);
+ kfree(av);
+ ai->vols_found -= 1;
+}
+
+/**
+ * early_erase_peb - erase a physical eraseblock.
+ * @ubi: UBI device description object
+ * @ai: attaching information
+ * @pnum: physical eraseblock number to erase;
+ * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)
+ *
+ * This function erases physical eraseblock 'pnum', and writes the erase
+ * counter header to it. This function should only be used on UBI device
+ * initialization stages, when the EBA sub-system had not been yet initialized.
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int early_erase_peb(struct ubi_device *ubi,
+ const struct ubi_attach_info *ai, int pnum, int ec)
+{
+ int err;
+ struct ubi_ec_hdr *ec_hdr;
+
+ if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
+ /*
+ * Erase counter overflow. Upgrade UBI and use 64-bit
+ * erase counters internally.
+ */
+ ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
+ return -EINVAL;
+ }
+
+ ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ if (!ec_hdr)
+ return -ENOMEM;
+
+ ec_hdr->ec = cpu_to_be64(ec);
+
+ err = ubi_io_sync_erase(ubi, pnum, 0);
+ if (err < 0)
+ goto out_free;
+
+ err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
+
+out_free:
+ kfree(ec_hdr);
+ return err;
+}
+
+/**
+ * ubi_early_get_peb - get a free physical eraseblock.
+ * @ubi: UBI device description object
+ * @ai: attaching information
+ *
+ * This function returns a free physical eraseblock. It is supposed to be
+ * called on the UBI initialization stages when the wear-leveling sub-system is
+ * not initialized yet. This function picks a physical eraseblocks from one of
+ * the lists, writes the EC header if it is needed, and removes it from the
+ * list.
+ *
+ * This function returns a pointer to the "aeb" of the found free PEB in case
+ * of success and an error code in case of failure.
+ */
+struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
+ struct ubi_attach_info *ai)
+{
+ int err = 0;
+ struct ubi_ainf_peb *aeb, *tmp_aeb;
+
+ if (!list_empty(&ai->free)) {
+ aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);
+ list_del(&aeb->u.list);
+ dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec);
+ return aeb;
+ }
+
+ /*
+ * We try to erase the first physical eraseblock from the erase list
+ * and pick it if we succeed, or try to erase the next one if not. And
+ * so forth. We don't want to take care about bad eraseblocks here -
+ * they'll be handled later.
+ */
+ list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {
+ if (aeb->ec == UBI_UNKNOWN)
+ aeb->ec = ai->mean_ec;
+
+ err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);
+ if (err)
+ continue;
+
+ aeb->ec += 1;
+ list_del(&aeb->u.list);
+ dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);
+ return aeb;
+ }
+
+ ubi_err("no free eraseblocks");
+ return ERR_PTR(-ENOSPC);
+}
+
+/**
+ * check_corruption - check the data area of PEB.
+ * @ubi: UBI device description object
+ * @vid_hrd: 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
+ * corruptions caused by power cuts and other reasons. If the PEB contains only
+ * 0xFF bytes in the data area, the VID header is most probably corrupted
+ * because of a power cut (%0 is returned in this case). Otherwise, it was
+ * probably corrupted for some other reasons (%1 is returned in this case). A
+ * negative error code is returned if a read error occurred.
+ *
+ * If the corruption reason was a power cut, UBI can safely erase this PEB.
+ * Otherwise, it should preserve it to avoid possibly destroying important
+ * information.
+ */
+static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
+ int pnum)
+{
+ int err;
+
+ mutex_lock(&ubi->buf_mutex);
+ memset(ubi->peb_buf, 0x00, ubi->leb_size);
+
+ err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start,
+ ubi->leb_size);
+ if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
+ /*
+ * Bit-flips or integrity errors while reading the data area.
+ * It is difficult to say for sure what type of corruption is
+ * this, but presumably a power cut happened while this PEB was
+ * erased, so it became unstable and corrupted, and should be
+ * erased.
+ */
+ err = 0;
+ goto out_unlock;
+ }
+
+ if (err)
+ goto out_unlock;
+
+ if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size))
+ goto out_unlock;
+
+ ubi_err("PEB %d contains corrupted VID header, and the data does not "
+ "contain all 0xFF, this may be a non-UBI PEB or a severe VID "
+ "header corruption which requires manual inspection", pnum);
+ ubi_dump_vid_hdr(vid_hdr);
+ dbg_msg("hexdump of PEB %d offset %d, length %d",
+ pnum, ubi->leb_start, ubi->leb_size);
+ ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+ ubi->peb_buf, ubi->leb_size, 1);
+ err = 1;
+
+out_unlock:
+ mutex_unlock(&ubi->buf_mutex);
+ return err;
+}
+
+/**
+ * scan_peb - scan and process UBI headers of a PEB.
+ * @ubi: UBI device description object
+ * @ai: attaching information
+ * @pnum: the physical eraseblock number
+ *
+ * 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
+ * "attaching info" structure. Returns zero if the physical eraseblock was
+ * 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)
+{
+ long long uninitialized_var(ec);
+ int err, bitflips = 0, vol_id, ec_err = 0;
+
+ dbg_bld("scan PEB %d", pnum);
+
+ /* Skip bad physical eraseblocks */
+ err = ubi_io_is_bad(ubi, pnum);
+ if (err < 0)
+ return err;
+ else if (err) {
+ ai->bad_peb_count += 1;
+ return 0;
+ }
+
+ err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
+ if (err < 0)
+ return err;
+ switch (err) {
+ case 0:
+ break;
+ case UBI_IO_BITFLIPS:
+ bitflips = 1;
+ break;
+ case UBI_IO_FF:
+ ai->empty_peb_count += 1;
+ return add_to_list(ai, pnum, UBI_UNKNOWN, 0,
+ &ai->erase);
+ case UBI_IO_FF_BITFLIPS:
+ ai->empty_peb_count += 1;
+ return add_to_list(ai, pnum, UBI_UNKNOWN, 1,
+ &ai->erase);
+ case UBI_IO_BAD_HDR_EBADMSG:
+ case UBI_IO_BAD_HDR:
+ /*
+ * We have to also look at the VID header, possibly it is not
+ * corrupted. Set %bitflips flag in order to make this PEB be
+ * moved and EC be re-created.
+ */
+ ec_err = err;
+ ec = UBI_UNKNOWN;
+ bitflips = 1;
+ break;
+ default:
+ ubi_err("'ubi_io_read_ec_hdr()' returned unknown code %d", err);
+ return -EINVAL;
+ }
+
+ if (!ec_err) {
+ int image_seq;
+
+ /* Make sure UBI version is OK */
+ if (ech->version != UBI_VERSION) {
+ ubi_err("this UBI version is %d, image version is %d",
+ UBI_VERSION, (int)ech->version);
+ return -EINVAL;
+ }
+
+ ec = be64_to_cpu(ech->ec);
+ if (ec > UBI_MAX_ERASECOUNTER) {
+ /*
+ * Erase counter overflow. The EC headers have 64 bits
+ * reserved, but we anyway make use of only 31 bit
+ * values, as this seems to be enough for any existing
+ * flash. Upgrade UBI and use 64-bit erase counters
+ * internally.
+ */
+ ubi_err("erase counter overflow, max is %d",
+ UBI_MAX_ERASECOUNTER);
+ ubi_dump_ec_hdr(ech);
+ return -EINVAL;
+ }
+
+ /*
+ * Make sure that all PEBs have the same image sequence number.
+ * This allows us to detect situations when users flash UBI
+ * images incorrectly, so that the flash has the new UBI image
+ * and leftovers from the old one. This feature was added
+ * relatively recently, and the sequence number was always
+ * zero, because old UBI implementations always set it to zero.
+ * For this reasons, we do not panic if some PEBs have zero
+ * sequence number, while other PEBs have non-zero sequence
+ * number.
+ */
+ image_seq = be32_to_cpu(ech->image_seq);
+ if (!ubi->image_seq && image_seq)
+ ubi->image_seq = image_seq;
+ if (ubi->image_seq && image_seq &&
+ ubi->image_seq != image_seq) {
+ ubi_err("bad image sequence number %d in PEB %d, "
+ "expected %d", image_seq, pnum, ubi->image_seq);
+ ubi_dump_ec_hdr(ech);
+ return -EINVAL;
+ }
+ }
+
+ /* OK, we've done with the EC header, let's look at the VID header */
+
+ err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
+ if (err < 0)
+ return err;
+ switch (err) {
+ case 0:
+ break;
+ case UBI_IO_BITFLIPS:
+ bitflips = 1;
+ break;
+ case UBI_IO_BAD_HDR_EBADMSG:
+ if (ec_err == UBI_IO_BAD_HDR_EBADMSG)
+ /*
+ * Both EC and VID headers are corrupted and were read
+ * with data integrity error, probably this is a bad
+ * PEB, bit it is not marked as bad yet. This may also
+ * be a result of power cut during erasure.
+ */
+ ai->maybe_bad_peb_count += 1;
+ case UBI_IO_BAD_HDR:
+ if (ec_err)
+ /*
+ * Both headers are corrupted. There is a possibility
+ * that this a valid UBI PEB which has corresponding
+ * LEB, but the headers are corrupted. However, it is
+ * impossible to distinguish it from a PEB which just
+ * contains garbage because of a power cut during erase
+ * operation. So we just schedule this PEB for erasure.
+ *
+ * Besides, in case of NOR flash, we deliberately
+ * corrupt both headers because NOR flash erasure is
+ * slow and can start from the end.
+ */
+ err = 0;
+ else
+ /*
+ * The EC was OK, but the VID header is corrupted. We
+ * have to check what is in the data area.
+ */
+ err = check_corruption(ubi, vidh, pnum);
+
+ if (err < 0)
+ return err;
+ else if (!err)
+ /* This corruption is caused by a power cut */
+ err = add_to_list(ai, pnum, ec, 1, &ai->erase);
+ else
+ /* This is an unexpected corruption */
+ err = add_corrupted(ai, pnum, ec);
+ if (err)
+ return err;
+ goto adjust_mean_ec;
+ case UBI_IO_FF_BITFLIPS:
+ err = add_to_list(ai, pnum, ec, 1, &ai->erase);
+ if (err)
+ return err;
+ goto adjust_mean_ec;
+ case UBI_IO_FF:
+ if (ec_err)
+ err = add_to_list(ai, pnum, ec, 1, &ai->erase);
+ else
+ err = add_to_list(ai, pnum, ec, 0, &ai->free);
+ if (err)
+ return err;
+ goto adjust_mean_ec;
+ default:
+ ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d",
+ err);
+ return -EINVAL;
+ }
+
+ vol_id = be32_to_cpu(vidh->vol_id);
+ 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);
+ err = add_to_list(ai, pnum, ec, 1, &ai->erase);
+ if (err)
+ return err;
+ return 0;
+
+ case UBI_COMPAT_RO:
+ ubi_msg("read-only compatible internal volume %d:%d"
+ " found, switch to read-only mode",
+ vol_id, lnum);
+ ubi->ro_mode = 1;
+ break;
+
+ case UBI_COMPAT_PRESERVE:
+ ubi_msg("\"preserve\" compatible internal volume %d:%d"
+ " found", vol_id, lnum);
+ err = add_to_list(ai, pnum, ec, 0, &ai->alien);
+ if (err)
+ return err;
+ return 0;
+
+ case UBI_COMPAT_REJECT:
+ ubi_err("incompatible internal volume %d:%d found",
+ vol_id, lnum);
+ return -EINVAL;
+ }
+ }
+
+ if (ec_err)
+ ubi_warn("valid VID header but corrupted EC header at PEB %d",
+ pnum);
+ err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
+ if (err)
+ return err;
+
+adjust_mean_ec:
+ if (!ec_err) {
+ ai->ec_sum += ec;
+ ai->ec_count += 1;
+ if (ec > ai->max_ec)
+ ai->max_ec = ec;
+ if (ec < ai->min_ec)
+ ai->min_ec = ec;
+ }
+
+ return 0;
+}
+
+/**
+ * late_analysis - analyze the overall situation with PEB.
+ * @ubi: UBI device description object
+ * @ai: attaching information
+ *
+ * This is a helper function which takes a look what PEBs we have after we
+ * gather information about all of them ("ai" is compete). It decides whether
+ * the flash is empty and should be formatted of whether there are too many
+ * corrupted PEBs and we should not attach this MTD device. Returns zero if we
+ * should proceed with attaching the MTD device, and %-EINVAL if we should not.
+ */
+static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)
+{
+ struct ubi_ainf_peb *aeb;
+ int max_corr, peb_count;
+
+ peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count;
+ max_corr = peb_count / 20 ?: 8;
+
+ /*
+ * Few corrupted PEBs is not a problem and may be just a result of
+ * unclean reboots. However, many of them may indicate some problems
+ * with the flash HW or driver.
+ */
+ if (ai->corr_peb_count) {
+ ubi_err("%d PEBs are corrupted and preserved",
+ ai->corr_peb_count);
+ printk(KERN_ERR "Corrupted PEBs are:");
+ list_for_each_entry(aeb, &ai->corr, u.list)
+ printk(KERN_CONT " %d", aeb->pnum);
+ printk(KERN_CONT "\n");
+
+ /*
+ * If too many PEBs are corrupted, we refuse attaching,
+ * otherwise, only print a warning.
+ */
+ if (ai->corr_peb_count >= max_corr) {
+ ubi_err("too many corrupted PEBs, refusing");
+ return -EINVAL;
+ }
+ }
+
+ if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) {
+ /*
+ * All PEBs are empty, or almost all - a couple PEBs look like
+ * they may be bad PEBs which were not marked as bad yet.
+ *
+ * This piece of code basically tries to distinguish between
+ * the following situations:
+ *
+ * 1. Flash is empty, but there are few bad PEBs, which are not
+ * marked as bad so far, and which were read with error. We
+ * want to go ahead and format this flash. While formatting,
+ * the faulty PEBs will probably be marked as bad.
+ *
+ * 2. Flash contains non-UBI data and we do not want to format
+ * it and destroy possibly important information.
+ */
+ if (ai->maybe_bad_peb_count <= 2) {
+ ai->is_empty = 1;
+ ubi_msg("empty MTD device detected");
+ get_random_bytes(&ubi->image_seq,
+ sizeof(ubi->image_seq));
+ } else {
+ ubi_err("MTD device is not UBI-formatted and possibly "
+ "contains non-UBI data - refusing it");
+ return -EINVAL;
+ }
+
+ }
+
+ return 0;
+}
+
+/**
+ * scan_all - scan entire MTD device.
+ * @ubi: UBI device description object
+ *
+ * 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)
+{
+ 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;
+
+ vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!vidh)
+ goto out_ech;
+
+ for (pnum = 0; pnum < ubi->peb_count; pnum++) {
+ cond_resched();
+
+ dbg_gen("process PEB %d", pnum);
+ err = scan_peb(ubi, ai, pnum);
+ if (err < 0)
+ goto out_vidh;
+ }
+
+ dbg_msg("scanning is finished");
+
+ /* Calculate mean erase counter */
+ if (ai->ec_count)
+ ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
+
+ err = late_analysis(ubi, ai);
+ if (err)
+ goto out_vidh;
+
+ /*
+ * In case of unknown erase counter we use the mean erase counter
+ * value.
+ */
+ ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
+ ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
+ if (aeb->ec == UBI_UNKNOWN)
+ aeb->ec = ai->mean_ec;
+ }
+
+ list_for_each_entry(aeb, &ai->free, u.list) {
+ if (aeb->ec == UBI_UNKNOWN)
+ aeb->ec = ai->mean_ec;
+ }
+
+ list_for_each_entry(aeb, &ai->corr, u.list)
+ if (aeb->ec == UBI_UNKNOWN)
+ aeb->ec = ai->mean_ec;
+
+ list_for_each_entry(aeb, &ai->erase, u.list)
+ if (aeb->ec == UBI_UNKNOWN)
+ aeb->ec = ai->mean_ec;
+
+ err = self_check_ai(ubi, ai);
+ if (err)
+ goto out_vidh;
+
+ ubi_free_vid_hdr(ubi, vidh);
+ kfree(ech);
+
+ return ai;
+
+out_vidh:
+ ubi_free_vid_hdr(ubi, vidh);
+out_ech:
+ kfree(ech);
+out_ai:
+ ubi_destroy_ai(ai);
+ return ERR_PTR(err);
+}
+
+/**
+ * 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;
+ struct ubi_attach_info *ai;
+
+ ai = scan_all(ubi);
+ if (IS_ERR(ai))
+ return PTR_ERR(ai);
+
+ ubi->bad_peb_count = ai->bad_peb_count;
+ ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
+ ubi->corr_peb_count = ai->corr_peb_count;
+ ubi->max_ec = ai->max_ec;
+ ubi->mean_ec = ai->mean_ec;
+ ubi_msg("max. sequence number: %llu", ai->max_sqnum);
+
+ err = ubi_read_volume_table(ubi, ai);
+ if (err)
+ goto out_ai;
+
+ err = ubi_wl_init(ubi, ai);
+ if (err)
+ goto out_vtbl;
+
+ err = ubi_eba_init(ubi, ai);
+ if (err)
+ goto out_wl;
+
+ ubi_destroy_ai(ai);
+ return 0;
+
+out_wl:
+ ubi_wl_close(ubi);
+out_vtbl:
+ ubi_free_internal_volumes(ubi);
+ vfree(ubi->vtbl);
+out_ai:
+ ubi_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
+ * @ai: attaching information
+ *
+ * This function returns zero if the attaching information is all right, and a
+ * negative error code if not or if an error occurred.
+ */
+static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)
+{
+ int pnum, err, vols_found = 0;
+ struct rb_node *rb1, *rb2;
+ struct ubi_ainf_volume *av;
+ struct ubi_ainf_peb *aeb, *last_aeb;
+ uint8_t *buf;
+
+ if (!ubi->dbg->chk_gen)
+ return 0;
+
+ /*
+ * At first, check that attaching information is OK.
+ */
+ ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
+ int leb_count = 0;
+
+ cond_resched();
+
+ vols_found += 1;
+
+ if (ai->is_empty) {
+ ubi_err("bad is_empty flag");
+ goto bad_av;
+ }
+
+ if (av->vol_id < 0 || av->highest_lnum < 0 ||
+ av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 ||
+ av->data_pad < 0 || av->last_data_size < 0) {
+ ubi_err("negative values");
+ goto bad_av;
+ }
+
+ if (av->vol_id >= UBI_MAX_VOLUMES &&
+ av->vol_id < UBI_INTERNAL_VOL_START) {
+ ubi_err("bad vol_id");
+ goto bad_av;
+ }
+
+ if (av->vol_id > ai->highest_vol_id) {
+ ubi_err("highest_vol_id is %d, but vol_id %d is there",
+ ai->highest_vol_id, av->vol_id);
+ goto out;
+ }
+
+ if (av->vol_type != UBI_DYNAMIC_VOLUME &&
+ av->vol_type != UBI_STATIC_VOLUME) {
+ ubi_err("bad vol_type");
+ goto bad_av;
+ }
+
+ if (av->data_pad > ubi->leb_size / 2) {
+ ubi_err("bad data_pad");
+ goto bad_av;
+ }
+
+ last_aeb = NULL;
+ ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
+ cond_resched();
+
+ last_aeb = aeb;
+ leb_count += 1;
+
+ if (aeb->pnum < 0 || aeb->ec < 0) {
+ ubi_err("negative values");
+ goto bad_aeb;
+ }
+
+ if (aeb->ec < ai->min_ec) {
+ ubi_err("bad ai->min_ec (%d), %d found",
+ ai->min_ec, aeb->ec);
+ goto bad_aeb;
+ }
+
+ if (aeb->ec > ai->max_ec) {
+ ubi_err("bad ai->max_ec (%d), %d found",
+ ai->max_ec, aeb->ec);
+ goto bad_aeb;
+ }
+
+ if (aeb->pnum >= ubi->peb_count) {
+ ubi_err("too high PEB number %d, total PEBs %d",
+ aeb->pnum, ubi->peb_count);
+ goto bad_aeb;
+ }
+
+ if (av->vol_type == UBI_STATIC_VOLUME) {
+ if (aeb->lnum >= av->used_ebs) {
+ ubi_err("bad lnum or used_ebs");
+ goto bad_aeb;
+ }
+ } else {
+ if (av->used_ebs != 0) {
+ ubi_err("non-zero used_ebs");
+ goto bad_aeb;
+ }
+ }
+
+ if (aeb->lnum > av->highest_lnum) {
+ ubi_err("incorrect highest_lnum or lnum");
+ goto bad_aeb;
+ }
+ }
+
+ if (av->leb_count != leb_count) {
+ ubi_err("bad leb_count, %d objects in the tree",
+ leb_count);
+ goto bad_av;
+ }
+
+ if (!last_aeb)
+ continue;
+
+ aeb = last_aeb;
+
+ if (aeb->lnum != av->highest_lnum) {
+ ubi_err("bad highest_lnum");
+ goto bad_aeb;
+ }
+ }
+
+ if (vols_found != ai->vols_found) {
+ ubi_err("bad ai->vols_found %d, should be %d",
+ ai->vols_found, vols_found);
+ goto out;
+ }
+
+ /* Check that attaching information is correct */
+ ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
+ last_aeb = NULL;
+ ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
+ int vol_type;
+
+ cond_resched();
+
+ last_aeb = aeb;
+
+ err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidh, 1);
+ if (err && err != UBI_IO_BITFLIPS) {
+ ubi_err("VID header is not OK (%d)", err);
+ if (err > 0)
+ err = -EIO;
+ return err;
+ }
+
+ vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
+ UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
+ if (av->vol_type != vol_type) {
+ ubi_err("bad vol_type");
+ goto bad_vid_hdr;
+ }
+
+ if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
+ ubi_err("bad sqnum %llu", aeb->sqnum);
+ goto bad_vid_hdr;
+ }
+
+ if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
+ ubi_err("bad vol_id %d", av->vol_id);
+ goto bad_vid_hdr;
+ }
+
+ if (av->compat != vidh->compat) {
+ ubi_err("bad compat %d", vidh->compat);
+ goto bad_vid_hdr;
+ }
+
+ if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
+ ubi_err("bad lnum %d", aeb->lnum);
+ goto bad_vid_hdr;
+ }
+
+ if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
+ ubi_err("bad used_ebs %d", av->used_ebs);
+ goto bad_vid_hdr;
+ }
+
+ if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
+ ubi_err("bad data_pad %d", av->data_pad);
+ goto bad_vid_hdr;
+ }
+ }
+
+ if (!last_aeb)
+ continue;
+
+ if (av->highest_lnum != be32_to_cpu(vidh->lnum)) {
+ ubi_err("bad highest_lnum %d", av->highest_lnum);
+ goto bad_vid_hdr;
+ }
+
+ if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
+ ubi_err("bad last_data_size %d", av->last_data_size);
+ goto bad_vid_hdr;
+ }
+ }
+
+ /*
+ * Make sure that all the physical eraseblocks are in one of the lists
+ * or trees.
+ */
+ buf = kzalloc(ubi->peb_count, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ for (pnum = 0; pnum < ubi->peb_count; pnum++) {
+ err = ubi_io_is_bad(ubi, pnum);
+ if (err < 0) {
+ kfree(buf);
+ return err;
+ } else if (err)
+ buf[pnum] = 1;
+ }
+
+ ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
+ ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
+ buf[aeb->pnum] = 1;
+
+ list_for_each_entry(aeb, &ai->free, u.list)
+ buf[aeb->pnum] = 1;
+
+ list_for_each_entry(aeb, &ai->corr, u.list)
+ buf[aeb->pnum] = 1;
+
+ list_for_each_entry(aeb, &ai->erase, u.list)
+ buf[aeb->pnum] = 1;
+
+ list_for_each_entry(aeb, &ai->alien, u.list)
+ buf[aeb->pnum] = 1;
+
+ err = 0;
+ for (pnum = 0; pnum < ubi->peb_count; pnum++)
+ if (!buf[pnum]) {
+ ubi_err("PEB %d is not referred", pnum);
+ err = 1;
+ }
+
+ kfree(buf);
+ if (err)
+ goto out;
+ return 0;
+
+bad_aeb:
+ ubi_err("bad attaching information about LEB %d", aeb->lnum);
+ ubi_dump_aeb(aeb, 0);
+ ubi_dump_av(av);
+ goto out;
+
+bad_av:
+ ubi_err("bad attaching information about volume %d", av->vol_id);
+ ubi_dump_av(av);
+ goto out;
+
+bad_vid_hdr:
+ ubi_err("bad attaching information about volume %d", av->vol_id);
+ ubi_dump_av(av);
+ ubi_dump_vid_hdr(vidh);
+
+out:
+ dump_stack();
+ return -EINVAL;
+}
+++ /dev/null
-/*
- * Copyright (c) International Business Machines Corp., 2006
- *
- * 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, or
- * (at your option) any later version.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Author: Artem Bityutskiy (Битюцкий Артём)
- */
-
-/*
- * UBI attaching sub-system.
- *
- * This sub-system is responsible for attaching MTD devices and it also
- * implements flash media scanning.
- *
- * The attaching information is represented by a &struct ubi_attach_info'
- * object. Information about volumes is represented by &struct ubi_ainf_volume
- * objects which are kept in volume RB-tree with root at the @volumes field.
- * The RB-tree is indexed by the volume ID.
- *
- * Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These
- * objects are kept in per-volume RB-trees with the root at the corresponding
- * &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of
- * per-volume objects and each of these objects is the root of RB-tree of
- * per-LEB objects.
- *
- * Corrupted physical eraseblocks are put to the @corr list, free physical
- * eraseblocks are put to the @free list and the physical eraseblock to be
- * erased are put to the @erase list.
- *
- * About corruptions
- * ~~~~~~~~~~~~~~~~~
- *
- * UBI protects EC and VID headers with CRC-32 checksums, so it can detect
- * whether the headers are corrupted or not. Sometimes UBI also protects the
- * data with CRC-32, e.g., when it executes the atomic LEB change operation, or
- * when it moves the contents of a PEB for wear-leveling purposes.
- *
- * UBI tries to distinguish between 2 types of corruptions.
- *
- * 1. Corruptions caused by power cuts. These are expected corruptions and UBI
- * tries to handle them gracefully, without printing too many warnings and
- * error messages. The idea is that we do not lose important data in these
- * cases - we may lose only the data which were being written to the media just
- * before the power cut happened, and the upper layers (e.g., UBIFS) are
- * supposed to handle such data losses (e.g., by using the FS journal).
- *
- * When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like
- * the reason is a power cut, UBI puts this PEB to the @erase list, and all
- * PEBs in the @erase list are scheduled for erasure later.
- *
- * 2. Unexpected corruptions which are not caused by power cuts. During
- * attaching, such PEBs are put to the @corr list and UBI preserves them.
- * Obviously, this lessens the amount of available PEBs, and if at some point
- * UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs
- * about such PEBs every time the MTD device is attached.
- *
- * However, it is difficult to reliably distinguish between these types of
- * corruptions and UBI's strategy is as follows (in case of attaching by
- * scanning). UBI assumes corruption type 2 if the VID header is corrupted and
- * the data area does not contain all 0xFFs, and there were no bit-flips or
- * integrity errors (e.g., ECC errors in case of NAND) while reading the data
- * area. Otherwise UBI assumes corruption type 1. So the decision criteria
- * are as follows.
- * o If the data area contains only 0xFFs, there are no data, and it is safe
- * to just erase this PEB - this is corruption type 1.
- * o If the data area has bit-flips or data integrity errors (ECC errors on
- * NAND), it is probably a PEB which was being erased when power cut
- * happened, so this is corruption type 1. However, this is just a guess,
- * which might be wrong.
- * o Otherwise this it corruption type 2.
- */
-
-#include <linux/err.h>
-#include <linux/slab.h>
-#include <linux/crc32.h>
-#include <linux/math64.h>
-#include <linux/random.h>
-#include "ubi.h"
-
-static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);
-
-/* Temporary variables used during scanning */
-static struct ubi_ec_hdr *ech;
-static struct ubi_vid_hdr *vidh;
-
-/**
- * add_to_list - add physical eraseblock to a list.
- * @ai: attaching information
- * @pnum: physical eraseblock number to add
- * @ec: erase counter of the physical eraseblock
- * @to_head: if not zero, add to the head of the list
- * @list: the list to add to
- *
- * This function allocates a 'struct ubi_ainf_peb' object for physical
- * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.
- * If @to_head is not zero, PEB will be added to the head of the list, which
- * basically means it will be processed first later. E.g., we add corrupted
- * PEBs (corrupted due to power cuts) to the head of the erase list to make
- * sure we erase them first and get rid of corruptions ASAP. This function
- * returns zero in case of success and a negative error code in case of
- * failure.
- */
-static int add_to_list(struct ubi_attach_info *ai, int pnum, int ec,
- int to_head, struct list_head *list)
-{
- struct ubi_ainf_peb *aeb;
-
- if (list == &ai->free) {
- dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
- } else if (list == &ai->erase) {
- dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
- } else if (list == &ai->alien) {
- dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
- ai->alien_peb_count += 1;
- } else
- BUG();
-
- aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
- if (!aeb)
- return -ENOMEM;
-
- aeb->pnum = pnum;
- aeb->ec = ec;
- if (to_head)
- list_add(&aeb->u.list, list);
- else
- list_add_tail(&aeb->u.list, list);
- return 0;
-}
-
-/**
- * add_corrupted - add a corrupted physical eraseblock.
- * @ai: attaching information
- * @pnum: physical eraseblock number to add
- * @ec: erase counter of the physical eraseblock
- *
- * This function allocates a 'struct ubi_ainf_peb' object for a corrupted
- * physical eraseblock @pnum and adds it to the 'corr' list. The corruption
- * was presumably not caused by a power cut. Returns zero in case of success
- * and a negative error code in case of failure.
- */
-static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
-{
- struct ubi_ainf_peb *aeb;
-
- dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
-
- aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
- if (!aeb)
- return -ENOMEM;
-
- ai->corr_peb_count += 1;
- aeb->pnum = pnum;
- aeb->ec = ec;
- list_add(&aeb->u.list, &ai->corr);
- return 0;
-}
-
-/**
- * validate_vid_hdr - check volume identifier header.
- * @vid_hdr: the volume identifier header to check
- * @av: information about the volume this logical eraseblock belongs to
- * @pnum: physical eraseblock number the VID header came from
- *
- * This function checks that data stored in @vid_hdr is consistent. Returns
- * non-zero if an inconsistency was found and zero if not.
- *
- * Note, UBI does sanity check of everything it reads from the flash media.
- * Most of the checks are done in the I/O sub-system. Here we check that the
- * information in the VID header is consistent to the information in other VID
- * headers of the same volume.
- */
-static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
- const struct ubi_ainf_volume *av, int pnum)
-{
- int vol_type = vid_hdr->vol_type;
- int vol_id = be32_to_cpu(vid_hdr->vol_id);
- int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
- int data_pad = be32_to_cpu(vid_hdr->data_pad);
-
- if (av->leb_count != 0) {
- int av_vol_type;
-
- /*
- * This is not the first logical eraseblock belonging to this
- * volume. Ensure that the data in its VID header is consistent
- * to the data in previous logical eraseblock headers.
- */
-
- if (vol_id != av->vol_id) {
- ubi_err("inconsistent vol_id");
- goto bad;
- }
-
- if (av->vol_type == UBI_STATIC_VOLUME)
- av_vol_type = UBI_VID_STATIC;
- else
- av_vol_type = UBI_VID_DYNAMIC;
-
- if (vol_type != av_vol_type) {
- ubi_err("inconsistent vol_type");
- goto bad;
- }
-
- if (used_ebs != av->used_ebs) {
- ubi_err("inconsistent used_ebs");
- goto bad;
- }
-
- if (data_pad != av->data_pad) {
- ubi_err("inconsistent data_pad");
- goto bad;
- }
- }
-
- return 0;
-
-bad:
- ubi_err("inconsistent VID header at PEB %d", pnum);
- ubi_dump_vid_hdr(vid_hdr);
- ubi_dump_av(av);
- return -EINVAL;
-}
-
-/**
- * add_volume - add volume to the attaching information.
- * @ai: attaching information
- * @vol_id: ID of the volume to add
- * @pnum: physical eraseblock number
- * @vid_hdr: volume identifier header
- *
- * If the volume corresponding to the @vid_hdr logical eraseblock is already
- * present in the attaching information, this function does nothing. Otherwise
- * it adds corresponding volume to the attaching information. Returns a pointer
- * to the allocated "av" object in case of success and a negative error code in
- * case of failure.
- */
-static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
- int vol_id, int pnum,
- const struct ubi_vid_hdr *vid_hdr)
-{
- struct ubi_ainf_volume *av;
- struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
-
- ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
-
- /* Walk the volume RB-tree to look if this volume is already present */
- while (*p) {
- parent = *p;
- av = rb_entry(parent, struct ubi_ainf_volume, rb);
-
- if (vol_id == av->vol_id)
- return av;
-
- if (vol_id > av->vol_id)
- p = &(*p)->rb_left;
- else
- p = &(*p)->rb_right;
- }
-
- /* The volume is absent - add it */
- av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
- if (!av)
- return ERR_PTR(-ENOMEM);
-
- av->highest_lnum = av->leb_count = 0;
- av->vol_id = vol_id;
- av->root = RB_ROOT;
- av->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
- av->data_pad = be32_to_cpu(vid_hdr->data_pad);
- av->compat = vid_hdr->compat;
- av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
- : UBI_STATIC_VOLUME;
- if (vol_id > ai->highest_vol_id)
- ai->highest_vol_id = vol_id;
-
- rb_link_node(&av->rb, parent, p);
- rb_insert_color(&av->rb, &ai->volumes);
- ai->vols_found += 1;
- dbg_bld("added volume %d", vol_id);
- return av;
-}
-
-/**
- * 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
- * compare
- * @vid_hdr: volume identifier header of the second logical eraseblock
- *
- * This function compares 2 copies of a LEB and informs which one is newer. In
- * case of success this function returns a positive value, in case of failure, a
- * negative error code is returned. The success return codes use the following
- * bits:
- * o bit 0 is cleared: the first PEB (described by @aeb) is newer than the
- * second PEB (described by @pnum and @vid_hdr);
- * o bit 0 is set: the second PEB is newer;
- * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
- * o bit 1 is set: bit-flips were detected in the newer LEB;
- * 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 pnum, const struct ubi_vid_hdr *vid_hdr)
-{
- void *buf;
- int len, err, second_is_newer, bitflips = 0, corrupted = 0;
- uint32_t data_crc, crc;
- struct ubi_vid_hdr *vh = NULL;
- unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
-
- if (sqnum2 == aeb->sqnum) {
- /*
- * This must be a really ancient UBI image which has been
- * created before sequence numbers support has been added. At
- * that times we used 32-bit LEB versions stored in logical
- * eraseblocks. That was before UBI got into mainline. We do not
- * support these images anymore. Well, those images still work,
- * but only if no unclean reboots happened.
- */
- ubi_err("unsupported on-flash UBI format\n");
- return -EINVAL;
- }
-
- /* Obviously the LEB with lower sequence counter is older */
- second_is_newer = (sqnum2 > aeb->sqnum);
-
- /*
- * Now we know which copy is newer. If the copy flag of the PEB with
- * newer version is not set, then we just return, otherwise we have to
- * check data CRC. For the second PEB we already have the VID header,
- * for the first one - we'll need to re-read it from flash.
- *
- * Note: this may be optimized so that we wouldn't read twice.
- */
-
- if (second_is_newer) {
- if (!vid_hdr->copy_flag) {
- /* It is not a copy, so it is newer */
- dbg_bld("second PEB %d is newer, copy_flag is unset",
- pnum);
- return 1;
- }
- } else {
- if (!aeb->copy_flag) {
- /* It is not a copy, so it is newer */
- dbg_bld("first PEB %d is newer, copy_flag is unset",
- pnum);
- return bitflips << 1;
- }
-
- vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
- if (!vh)
- return -ENOMEM;
-
- pnum = aeb->pnum;
- err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
- if (err) {
- if (err == UBI_IO_BITFLIPS)
- bitflips = 1;
- else {
- ubi_err("VID of PEB %d header is bad, but it "
- "was OK earlier, err %d", pnum, err);
- if (err > 0)
- err = -EIO;
-
- goto out_free_vidh;
- }
- }
-
- vid_hdr = vh;
- }
-
- /* Read the data of the copy and check the CRC */
-
- len = be32_to_cpu(vid_hdr->data_size);
- buf = vmalloc(len);
- if (!buf) {
- err = -ENOMEM;
- goto out_free_vidh;
- }
-
- err = ubi_io_read_data(ubi, buf, pnum, 0, len);
- if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
- goto out_free_buf;
-
- data_crc = be32_to_cpu(vid_hdr->data_crc);
- crc = crc32(UBI_CRC32_INIT, buf, len);
- if (crc != data_crc) {
- dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
- pnum, crc, data_crc);
- corrupted = 1;
- bitflips = 0;
- second_is_newer = !second_is_newer;
- } else {
- dbg_bld("PEB %d CRC is OK", pnum);
- bitflips = !!err;
- }
-
- vfree(buf);
- ubi_free_vid_hdr(ubi, vh);
-
- if (second_is_newer)
- dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
- else
- dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
-
- return second_is_newer | (bitflips << 1) | (corrupted << 2);
-
-out_free_buf:
- vfree(buf);
-out_free_vidh:
- ubi_free_vid_hdr(ubi, vh);
- return err;
-}
-
-/**
- * ubi_add_to_av - add used physical eraseblock to the attaching information.
- * @ubi: UBI device description object
- * @ai: attaching information
- * @pnum: the physical eraseblock number
- * @ec: erase counter
- * @vid_hdr: the volume identifier header
- * @bitflips: if bit-flips were detected when this physical eraseblock was read
- *
- * This function adds information about a used physical eraseblock to the
- * 'used' tree of the corresponding volume. The function is rather complex
- * because it has to handle cases when this is not the first physical
- * eraseblock belonging to the same logical eraseblock, and the newer one has
- * to be picked, while the older one has to be dropped. This function returns
- * zero in case of success and a negative error code in case of failure.
- */
-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)
-{
- int err, vol_id, lnum;
- unsigned long long sqnum;
- struct ubi_ainf_volume *av;
- struct ubi_ainf_peb *aeb;
- struct rb_node **p, *parent = NULL;
-
- vol_id = be32_to_cpu(vid_hdr->vol_id);
- lnum = be32_to_cpu(vid_hdr->lnum);
- sqnum = be64_to_cpu(vid_hdr->sqnum);
-
- dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
- pnum, vol_id, lnum, ec, sqnum, bitflips);
-
- av = add_volume(ai, vol_id, pnum, vid_hdr);
- if (IS_ERR(av))
- return PTR_ERR(av);
-
- if (ai->max_sqnum < sqnum)
- ai->max_sqnum = sqnum;
-
- /*
- * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
- * if this is the first instance of this logical eraseblock or not.
- */
- p = &av->root.rb_node;
- while (*p) {
- int cmp_res;
-
- parent = *p;
- aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
- if (lnum != aeb->lnum) {
- if (lnum < aeb->lnum)
- p = &(*p)->rb_left;
- else
- p = &(*p)->rb_right;
- continue;
- }
-
- /*
- * There is already a physical eraseblock describing the same
- * logical eraseblock present.
- */
-
- dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",
- aeb->pnum, aeb->sqnum, aeb->ec);
-
- /*
- * Make sure that the logical eraseblocks have different
- * sequence numbers. Otherwise the image is bad.
- *
- * However, if the sequence number is zero, we assume it must
- * be an ancient UBI image from the era when UBI did not have
- * 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
- * images, but refuse attaching old images with duplicated
- * logical eraseblocks because there was an unclean reboot.
- */
- if (aeb->sqnum == sqnum && sqnum != 0) {
- ubi_err("two LEBs with same sequence number %llu",
- sqnum);
- ubi_dump_aeb(aeb, 0);
- ubi_dump_vid_hdr(vid_hdr);
- return -EINVAL;
- }
-
- /*
- * Now we have to drop the older one and preserve the newer
- * one.
- */
- cmp_res = compare_lebs(ubi, aeb, pnum, vid_hdr);
- if (cmp_res < 0)
- return cmp_res;
-
- if (cmp_res & 1) {
- /*
- * This logical eraseblock is newer than the one
- * found earlier.
- */
- err = validate_vid_hdr(vid_hdr, av, pnum);
- if (err)
- return err;
-
- err = add_to_list(ai, aeb->pnum, aeb->ec, cmp_res & 4,
- &ai->erase);
- if (err)
- return err;
-
- aeb->ec = ec;
- aeb->pnum = pnum;
- aeb->scrub = ((cmp_res & 2) || bitflips);
- aeb->copy_flag = vid_hdr->copy_flag;
- aeb->sqnum = sqnum;
-
- if (av->highest_lnum == lnum)
- av->last_data_size =
- be32_to_cpu(vid_hdr->data_size);
-
- return 0;
- } else {
- /*
- * This logical eraseblock is older than the one found
- * previously.
- */
- return add_to_list(ai, pnum, ec, cmp_res & 4,
- &ai->erase);
- }
- }
-
- /*
- * We've met this logical eraseblock for the first time, add it to the
- * attaching information.
- */
-
- err = validate_vid_hdr(vid_hdr, av, pnum);
- if (err)
- return err;
-
- aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
- if (!aeb)
- return -ENOMEM;
-
- aeb->ec = ec;
- aeb->pnum = pnum;
- aeb->lnum = lnum;
- aeb->scrub = bitflips;
- aeb->copy_flag = vid_hdr->copy_flag;
- aeb->sqnum = sqnum;
-
- if (av->highest_lnum <= lnum) {
- av->highest_lnum = lnum;
- av->last_data_size = be32_to_cpu(vid_hdr->data_size);
- }
-
- av->leb_count += 1;
- rb_link_node(&aeb->u.rb, parent, p);
- rb_insert_color(&aeb->u.rb, &av->root);
- return 0;
-}
-
-/**
- * ubi_find_av - find volume in the attaching information.
- * @ai: attaching information
- * @vol_id: the requested volume ID
- *
- * This function returns a pointer to the volume description or %NULL if there
- * are no data about this volume in the attaching information.
- */
-struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
- int vol_id)
-{
- struct ubi_ainf_volume *av;
- struct rb_node *p = ai->volumes.rb_node;
-
- while (p) {
- av = rb_entry(p, struct ubi_ainf_volume, rb);
-
- if (vol_id == av->vol_id)
- return av;
-
- if (vol_id > av->vol_id)
- p = p->rb_left;
- else
- p = p->rb_right;
- }
-
- return NULL;
-}
-
-/**
- * ubi_remove_av - delete attaching information about a volume.
- * @ai: attaching information
- * @av: the volume attaching information to delete
- */
-void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
-{
- struct rb_node *rb;
- struct ubi_ainf_peb *aeb;
-
- dbg_bld("remove attaching information about volume %d", av->vol_id);
-
- while ((rb = rb_first(&av->root))) {
- aeb = rb_entry(rb, struct ubi_ainf_peb, u.rb);
- rb_erase(&aeb->u.rb, &av->root);
- list_add_tail(&aeb->u.list, &ai->erase);
- }
-
- rb_erase(&av->rb, &ai->volumes);
- kfree(av);
- ai->vols_found -= 1;
-}
-
-/**
- * early_erase_peb - erase a physical eraseblock.
- * @ubi: UBI device description object
- * @ai: attaching information
- * @pnum: physical eraseblock number to erase;
- * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)
- *
- * This function erases physical eraseblock 'pnum', and writes the erase
- * counter header to it. This function should only be used on UBI device
- * initialization stages, when the EBA sub-system had not been yet initialized.
- * This function returns zero in case of success and a negative error code in
- * case of failure.
- */
-static int early_erase_peb(struct ubi_device *ubi,
- const struct ubi_attach_info *ai, int pnum, int ec)
-{
- int err;
- struct ubi_ec_hdr *ec_hdr;
-
- if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
- /*
- * Erase counter overflow. Upgrade UBI and use 64-bit
- * erase counters internally.
- */
- ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
- return -EINVAL;
- }
-
- ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
- if (!ec_hdr)
- return -ENOMEM;
-
- ec_hdr->ec = cpu_to_be64(ec);
-
- err = ubi_io_sync_erase(ubi, pnum, 0);
- if (err < 0)
- goto out_free;
-
- err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
-
-out_free:
- kfree(ec_hdr);
- return err;
-}
-
-/**
- * ubi_early_get_peb - get a free physical eraseblock.
- * @ubi: UBI device description object
- * @ai: attaching information
- *
- * This function returns a free physical eraseblock. It is supposed to be
- * called on the UBI initialization stages when the wear-leveling sub-system is
- * not initialized yet. This function picks a physical eraseblocks from one of
- * the lists, writes the EC header if it is needed, and removes it from the
- * list.
- *
- * This function returns a pointer to the "aeb" of the found free PEB in case
- * of success and an error code in case of failure.
- */
-struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
- struct ubi_attach_info *ai)
-{
- int err = 0;
- struct ubi_ainf_peb *aeb, *tmp_aeb;
-
- if (!list_empty(&ai->free)) {
- aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);
- list_del(&aeb->u.list);
- dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec);
- return aeb;
- }
-
- /*
- * We try to erase the first physical eraseblock from the erase list
- * and pick it if we succeed, or try to erase the next one if not. And
- * so forth. We don't want to take care about bad eraseblocks here -
- * they'll be handled later.
- */
- list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
-
- err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);
- if (err)
- continue;
-
- aeb->ec += 1;
- list_del(&aeb->u.list);
- dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);
- return aeb;
- }
-
- ubi_err("no free eraseblocks");
- return ERR_PTR(-ENOSPC);
-}
-
-/**
- * check_corruption - check the data area of PEB.
- * @ubi: UBI device description object
- * @vid_hrd: 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
- * corruptions caused by power cuts and other reasons. If the PEB contains only
- * 0xFF bytes in the data area, the VID header is most probably corrupted
- * because of a power cut (%0 is returned in this case). Otherwise, it was
- * probably corrupted for some other reasons (%1 is returned in this case). A
- * negative error code is returned if a read error occurred.
- *
- * If the corruption reason was a power cut, UBI can safely erase this PEB.
- * Otherwise, it should preserve it to avoid possibly destroying important
- * information.
- */
-static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
- int pnum)
-{
- int err;
-
- mutex_lock(&ubi->buf_mutex);
- memset(ubi->peb_buf, 0x00, ubi->leb_size);
-
- err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start,
- ubi->leb_size);
- if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
- /*
- * Bit-flips or integrity errors while reading the data area.
- * It is difficult to say for sure what type of corruption is
- * this, but presumably a power cut happened while this PEB was
- * erased, so it became unstable and corrupted, and should be
- * erased.
- */
- err = 0;
- goto out_unlock;
- }
-
- if (err)
- goto out_unlock;
-
- if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size))
- goto out_unlock;
-
- ubi_err("PEB %d contains corrupted VID header, and the data does not "
- "contain all 0xFF, this may be a non-UBI PEB or a severe VID "
- "header corruption which requires manual inspection", pnum);
- ubi_dump_vid_hdr(vid_hdr);
- dbg_msg("hexdump of PEB %d offset %d, length %d",
- pnum, ubi->leb_start, ubi->leb_size);
- ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
- ubi->peb_buf, ubi->leb_size, 1);
- err = 1;
-
-out_unlock:
- mutex_unlock(&ubi->buf_mutex);
- return err;
-}
-
-/**
- * scan_peb - scan and process UBI headers of a PEB.
- * @ubi: UBI device description object
- * @ai: attaching information
- * @pnum: the physical eraseblock number
- *
- * 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
- * "attaching info" structure. Returns zero if the physical eraseblock was
- * 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)
-{
- long long uninitialized_var(ec);
- int err, bitflips = 0, vol_id, ec_err = 0;
-
- dbg_bld("scan PEB %d", pnum);
-
- /* Skip bad physical eraseblocks */
- err = ubi_io_is_bad(ubi, pnum);
- if (err < 0)
- return err;
- else if (err) {
- ai->bad_peb_count += 1;
- return 0;
- }
-
- err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
- if (err < 0)
- return err;
- switch (err) {
- case 0:
- break;
- case UBI_IO_BITFLIPS:
- bitflips = 1;
- break;
- case UBI_IO_FF:
- ai->empty_peb_count += 1;
- return add_to_list(ai, pnum, UBI_UNKNOWN, 0,
- &ai->erase);
- case UBI_IO_FF_BITFLIPS:
- ai->empty_peb_count += 1;
- return add_to_list(ai, pnum, UBI_UNKNOWN, 1,
- &ai->erase);
- case UBI_IO_BAD_HDR_EBADMSG:
- case UBI_IO_BAD_HDR:
- /*
- * We have to also look at the VID header, possibly it is not
- * corrupted. Set %bitflips flag in order to make this PEB be
- * moved and EC be re-created.
- */
- ec_err = err;
- ec = UBI_UNKNOWN;
- bitflips = 1;
- break;
- default:
- ubi_err("'ubi_io_read_ec_hdr()' returned unknown code %d", err);
- return -EINVAL;
- }
-
- if (!ec_err) {
- int image_seq;
-
- /* Make sure UBI version is OK */
- if (ech->version != UBI_VERSION) {
- ubi_err("this UBI version is %d, image version is %d",
- UBI_VERSION, (int)ech->version);
- return -EINVAL;
- }
-
- ec = be64_to_cpu(ech->ec);
- if (ec > UBI_MAX_ERASECOUNTER) {
- /*
- * Erase counter overflow. The EC headers have 64 bits
- * reserved, but we anyway make use of only 31 bit
- * values, as this seems to be enough for any existing
- * flash. Upgrade UBI and use 64-bit erase counters
- * internally.
- */
- ubi_err("erase counter overflow, max is %d",
- UBI_MAX_ERASECOUNTER);
- ubi_dump_ec_hdr(ech);
- return -EINVAL;
- }
-
- /*
- * Make sure that all PEBs have the same image sequence number.
- * This allows us to detect situations when users flash UBI
- * images incorrectly, so that the flash has the new UBI image
- * and leftovers from the old one. This feature was added
- * relatively recently, and the sequence number was always
- * zero, because old UBI implementations always set it to zero.
- * For this reasons, we do not panic if some PEBs have zero
- * sequence number, while other PEBs have non-zero sequence
- * number.
- */
- image_seq = be32_to_cpu(ech->image_seq);
- if (!ubi->image_seq && image_seq)
- ubi->image_seq = image_seq;
- if (ubi->image_seq && image_seq &&
- ubi->image_seq != image_seq) {
- ubi_err("bad image sequence number %d in PEB %d, "
- "expected %d", image_seq, pnum, ubi->image_seq);
- ubi_dump_ec_hdr(ech);
- return -EINVAL;
- }
- }
-
- /* OK, we've done with the EC header, let's look at the VID header */
-
- err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
- if (err < 0)
- return err;
- switch (err) {
- case 0:
- break;
- case UBI_IO_BITFLIPS:
- bitflips = 1;
- break;
- case UBI_IO_BAD_HDR_EBADMSG:
- if (ec_err == UBI_IO_BAD_HDR_EBADMSG)
- /*
- * Both EC and VID headers are corrupted and were read
- * with data integrity error, probably this is a bad
- * PEB, bit it is not marked as bad yet. This may also
- * be a result of power cut during erasure.
- */
- ai->maybe_bad_peb_count += 1;
- case UBI_IO_BAD_HDR:
- if (ec_err)
- /*
- * Both headers are corrupted. There is a possibility
- * that this a valid UBI PEB which has corresponding
- * LEB, but the headers are corrupted. However, it is
- * impossible to distinguish it from a PEB which just
- * contains garbage because of a power cut during erase
- * operation. So we just schedule this PEB for erasure.
- *
- * Besides, in case of NOR flash, we deliberately
- * corrupt both headers because NOR flash erasure is
- * slow and can start from the end.
- */
- err = 0;
- else
- /*
- * The EC was OK, but the VID header is corrupted. We
- * have to check what is in the data area.
- */
- err = check_corruption(ubi, vidh, pnum);
-
- if (err < 0)
- return err;
- else if (!err)
- /* This corruption is caused by a power cut */
- err = add_to_list(ai, pnum, ec, 1, &ai->erase);
- else
- /* This is an unexpected corruption */
- err = add_corrupted(ai, pnum, ec);
- if (err)
- return err;
- goto adjust_mean_ec;
- case UBI_IO_FF_BITFLIPS:
- err = add_to_list(ai, pnum, ec, 1, &ai->erase);
- if (err)
- return err;
- goto adjust_mean_ec;
- case UBI_IO_FF:
- if (ec_err)
- err = add_to_list(ai, pnum, ec, 1, &ai->erase);
- else
- err = add_to_list(ai, pnum, ec, 0, &ai->free);
- if (err)
- return err;
- goto adjust_mean_ec;
- default:
- ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d",
- err);
- return -EINVAL;
- }
-
- vol_id = be32_to_cpu(vidh->vol_id);
- 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);
- err = add_to_list(ai, pnum, ec, 1, &ai->erase);
- if (err)
- return err;
- return 0;
-
- case UBI_COMPAT_RO:
- ubi_msg("read-only compatible internal volume %d:%d"
- " found, switch to read-only mode",
- vol_id, lnum);
- ubi->ro_mode = 1;
- break;
-
- case UBI_COMPAT_PRESERVE:
- ubi_msg("\"preserve\" compatible internal volume %d:%d"
- " found", vol_id, lnum);
- err = add_to_list(ai, pnum, ec, 0, &ai->alien);
- if (err)
- return err;
- return 0;
-
- case UBI_COMPAT_REJECT:
- ubi_err("incompatible internal volume %d:%d found",
- vol_id, lnum);
- return -EINVAL;
- }
- }
-
- if (ec_err)
- ubi_warn("valid VID header but corrupted EC header at PEB %d",
- pnum);
- err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
- if (err)
- return err;
-
-adjust_mean_ec:
- if (!ec_err) {
- ai->ec_sum += ec;
- ai->ec_count += 1;
- if (ec > ai->max_ec)
- ai->max_ec = ec;
- if (ec < ai->min_ec)
- ai->min_ec = ec;
- }
-
- return 0;
-}
-
-/**
- * late_analysis - analyze the overall situation with PEB.
- * @ubi: UBI device description object
- * @ai: attaching information
- *
- * This is a helper function which takes a look what PEBs we have after we
- * gather information about all of them ("ai" is compete). It decides whether
- * the flash is empty and should be formatted of whether there are too many
- * corrupted PEBs and we should not attach this MTD device. Returns zero if we
- * should proceed with attaching the MTD device, and %-EINVAL if we should not.
- */
-static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)
-{
- struct ubi_ainf_peb *aeb;
- int max_corr, peb_count;
-
- peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count;
- max_corr = peb_count / 20 ?: 8;
-
- /*
- * Few corrupted PEBs is not a problem and may be just a result of
- * unclean reboots. However, many of them may indicate some problems
- * with the flash HW or driver.
- */
- if (ai->corr_peb_count) {
- ubi_err("%d PEBs are corrupted and preserved",
- ai->corr_peb_count);
- printk(KERN_ERR "Corrupted PEBs are:");
- list_for_each_entry(aeb, &ai->corr, u.list)
- printk(KERN_CONT " %d", aeb->pnum);
- printk(KERN_CONT "\n");
-
- /*
- * If too many PEBs are corrupted, we refuse attaching,
- * otherwise, only print a warning.
- */
- if (ai->corr_peb_count >= max_corr) {
- ubi_err("too many corrupted PEBs, refusing");
- return -EINVAL;
- }
- }
-
- if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) {
- /*
- * All PEBs are empty, or almost all - a couple PEBs look like
- * they may be bad PEBs which were not marked as bad yet.
- *
- * This piece of code basically tries to distinguish between
- * the following situations:
- *
- * 1. Flash is empty, but there are few bad PEBs, which are not
- * marked as bad so far, and which were read with error. We
- * want to go ahead and format this flash. While formatting,
- * the faulty PEBs will probably be marked as bad.
- *
- * 2. Flash contains non-UBI data and we do not want to format
- * it and destroy possibly important information.
- */
- if (ai->maybe_bad_peb_count <= 2) {
- ai->is_empty = 1;
- ubi_msg("empty MTD device detected");
- get_random_bytes(&ubi->image_seq,
- sizeof(ubi->image_seq));
- } else {
- ubi_err("MTD device is not UBI-formatted and possibly "
- "contains non-UBI data - refusing it");
- return -EINVAL;
- }
-
- }
-
- return 0;
-}
-
-/**
- * scan_all - scan entire MTD device.
- * @ubi: UBI device description object
- *
- * 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)
-{
- 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;
-
- vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
- if (!vidh)
- goto out_ech;
-
- for (pnum = 0; pnum < ubi->peb_count; pnum++) {
- cond_resched();
-
- dbg_gen("process PEB %d", pnum);
- err = scan_peb(ubi, ai, pnum);
- if (err < 0)
- goto out_vidh;
- }
-
- dbg_msg("scanning is finished");
-
- /* Calculate mean erase counter */
- if (ai->ec_count)
- ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
-
- err = late_analysis(ubi, ai);
- if (err)
- goto out_vidh;
-
- /*
- * In case of unknown erase counter we use the mean erase counter
- * value.
- */
- ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
- ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
- }
-
- list_for_each_entry(aeb, &ai->free, u.list) {
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
- }
-
- list_for_each_entry(aeb, &ai->corr, u.list)
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
-
- list_for_each_entry(aeb, &ai->erase, u.list)
- if (aeb->ec == UBI_UNKNOWN)
- aeb->ec = ai->mean_ec;
-
- err = self_check_ai(ubi, ai);
- if (err)
- goto out_vidh;
-
- ubi_free_vid_hdr(ubi, vidh);
- kfree(ech);
-
- return ai;
-
-out_vidh:
- ubi_free_vid_hdr(ubi, vidh);
-out_ech:
- kfree(ech);
-out_ai:
- ubi_destroy_ai(ai);
- return ERR_PTR(err);
-}
-
-/**
- * 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;
- struct ubi_attach_info *ai;
-
- ai = scan_all(ubi);
- if (IS_ERR(ai))
- return PTR_ERR(ai);
-
- ubi->bad_peb_count = ai->bad_peb_count;
- ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
- ubi->corr_peb_count = ai->corr_peb_count;
- ubi->max_ec = ai->max_ec;
- ubi->mean_ec = ai->mean_ec;
- ubi_msg("max. sequence number: %llu", ai->max_sqnum);
-
- err = ubi_read_volume_table(ubi, ai);
- if (err)
- goto out_ai;
-
- err = ubi_wl_init(ubi, ai);
- if (err)
- goto out_vtbl;
-
- err = ubi_eba_init(ubi, ai);
- if (err)
- goto out_wl;
-
- ubi_destroy_ai(ai);
- return 0;
-
-out_wl:
- ubi_wl_close(ubi);
-out_vtbl:
- ubi_free_internal_volumes(ubi);
- vfree(ubi->vtbl);
-out_ai:
- ubi_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
- * @ai: attaching information
- *
- * This function returns zero if the attaching information is all right, and a
- * negative error code if not or if an error occurred.
- */
-static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)
-{
- int pnum, err, vols_found = 0;
- struct rb_node *rb1, *rb2;
- struct ubi_ainf_volume *av;
- struct ubi_ainf_peb *aeb, *last_aeb;
- uint8_t *buf;
-
- if (!ubi->dbg->chk_gen)
- return 0;
-
- /*
- * At first, check that attaching information is OK.
- */
- ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
- int leb_count = 0;
-
- cond_resched();
-
- vols_found += 1;
-
- if (ai->is_empty) {
- ubi_err("bad is_empty flag");
- goto bad_av;
- }
-
- if (av->vol_id < 0 || av->highest_lnum < 0 ||
- av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 ||
- av->data_pad < 0 || av->last_data_size < 0) {
- ubi_err("negative values");
- goto bad_av;
- }
-
- if (av->vol_id >= UBI_MAX_VOLUMES &&
- av->vol_id < UBI_INTERNAL_VOL_START) {
- ubi_err("bad vol_id");
- goto bad_av;
- }
-
- if (av->vol_id > ai->highest_vol_id) {
- ubi_err("highest_vol_id is %d, but vol_id %d is there",
- ai->highest_vol_id, av->vol_id);
- goto out;
- }
-
- if (av->vol_type != UBI_DYNAMIC_VOLUME &&
- av->vol_type != UBI_STATIC_VOLUME) {
- ubi_err("bad vol_type");
- goto bad_av;
- }
-
- if (av->data_pad > ubi->leb_size / 2) {
- ubi_err("bad data_pad");
- goto bad_av;
- }
-
- last_aeb = NULL;
- ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
- cond_resched();
-
- last_aeb = aeb;
- leb_count += 1;
-
- if (aeb->pnum < 0 || aeb->ec < 0) {
- ubi_err("negative values");
- goto bad_aeb;
- }
-
- if (aeb->ec < ai->min_ec) {
- ubi_err("bad ai->min_ec (%d), %d found",
- ai->min_ec, aeb->ec);
- goto bad_aeb;
- }
-
- if (aeb->ec > ai->max_ec) {
- ubi_err("bad ai->max_ec (%d), %d found",
- ai->max_ec, aeb->ec);
- goto bad_aeb;
- }
-
- if (aeb->pnum >= ubi->peb_count) {
- ubi_err("too high PEB number %d, total PEBs %d",
- aeb->pnum, ubi->peb_count);
- goto bad_aeb;
- }
-
- if (av->vol_type == UBI_STATIC_VOLUME) {
- if (aeb->lnum >= av->used_ebs) {
- ubi_err("bad lnum or used_ebs");
- goto bad_aeb;
- }
- } else {
- if (av->used_ebs != 0) {
- ubi_err("non-zero used_ebs");
- goto bad_aeb;
- }
- }
-
- if (aeb->lnum > av->highest_lnum) {
- ubi_err("incorrect highest_lnum or lnum");
- goto bad_aeb;
- }
- }
-
- if (av->leb_count != leb_count) {
- ubi_err("bad leb_count, %d objects in the tree",
- leb_count);
- goto bad_av;
- }
-
- if (!last_aeb)
- continue;
-
- aeb = last_aeb;
-
- if (aeb->lnum != av->highest_lnum) {
- ubi_err("bad highest_lnum");
- goto bad_aeb;
- }
- }
-
- if (vols_found != ai->vols_found) {
- ubi_err("bad ai->vols_found %d, should be %d",
- ai->vols_found, vols_found);
- goto out;
- }
-
- /* Check that attaching information is correct */
- ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
- last_aeb = NULL;
- ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
- int vol_type;
-
- cond_resched();
-
- last_aeb = aeb;
-
- err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidh, 1);
- if (err && err != UBI_IO_BITFLIPS) {
- ubi_err("VID header is not OK (%d)", err);
- if (err > 0)
- err = -EIO;
- return err;
- }
-
- vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
- UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
- if (av->vol_type != vol_type) {
- ubi_err("bad vol_type");
- goto bad_vid_hdr;
- }
-
- if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
- ubi_err("bad sqnum %llu", aeb->sqnum);
- goto bad_vid_hdr;
- }
-
- if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
- ubi_err("bad vol_id %d", av->vol_id);
- goto bad_vid_hdr;
- }
-
- if (av->compat != vidh->compat) {
- ubi_err("bad compat %d", vidh->compat);
- goto bad_vid_hdr;
- }
-
- if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
- ubi_err("bad lnum %d", aeb->lnum);
- goto bad_vid_hdr;
- }
-
- if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
- ubi_err("bad used_ebs %d", av->used_ebs);
- goto bad_vid_hdr;
- }
-
- if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
- ubi_err("bad data_pad %d", av->data_pad);
- goto bad_vid_hdr;
- }
- }
-
- if (!last_aeb)
- continue;
-
- if (av->highest_lnum != be32_to_cpu(vidh->lnum)) {
- ubi_err("bad highest_lnum %d", av->highest_lnum);
- goto bad_vid_hdr;
- }
-
- if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
- ubi_err("bad last_data_size %d", av->last_data_size);
- goto bad_vid_hdr;
- }
- }
-
- /*
- * Make sure that all the physical eraseblocks are in one of the lists
- * or trees.
- */
- buf = kzalloc(ubi->peb_count, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- for (pnum = 0; pnum < ubi->peb_count; pnum++) {
- err = ubi_io_is_bad(ubi, pnum);
- if (err < 0) {
- kfree(buf);
- return err;
- } else if (err)
- buf[pnum] = 1;
- }
-
- ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
- ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
- buf[aeb->pnum] = 1;
-
- list_for_each_entry(aeb, &ai->free, u.list)
- buf[aeb->pnum] = 1;
-
- list_for_each_entry(aeb, &ai->corr, u.list)
- buf[aeb->pnum] = 1;
-
- list_for_each_entry(aeb, &ai->erase, u.list)
- buf[aeb->pnum] = 1;
-
- list_for_each_entry(aeb, &ai->alien, u.list)
- buf[aeb->pnum] = 1;
-
- err = 0;
- for (pnum = 0; pnum < ubi->peb_count; pnum++)
- if (!buf[pnum]) {
- ubi_err("PEB %d is not referred", pnum);
- err = 1;
- }
-
- kfree(buf);
- if (err)
- goto out;
- return 0;
-
-bad_aeb:
- ubi_err("bad attaching information about LEB %d", aeb->lnum);
- ubi_dump_aeb(aeb, 0);
- ubi_dump_av(av);
- goto out;
-
-bad_av:
- ubi_err("bad attaching information about volume %d", av->vol_id);
- ubi_dump_av(av);
- goto out;
-
-bad_vid_hdr:
- ubi_err("bad attaching information about volume %d", av->vol_id);
- ubi_dump_av(av);
- ubi_dump_vid_hdr(vidh);
-
-out:
- dump_stack();
- return -EINVAL;
-}
projects / cascardo / linux.git / commitdiff