v4.19.13 snapshot.
diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c
new file mode 100644
index 0000000..93ceea4
--- /dev/null
+++ b/drivers/mtd/ubi/attach.c
@@ -0,0 +1,1935 @@
+/*
+ * 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 is 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);
+
+#define AV_FIND BIT(0)
+#define AV_ADD BIT(1)
+#define AV_FIND_OR_ADD (AV_FIND | AV_ADD)
+
+/**
+ * find_or_add_av - internal function to find a volume, add a volume or do
+ * both (find and add if missing).
+ * @ai: attaching information
+ * @vol_id: the requested volume ID
+ * @flags: a combination of the %AV_FIND and %AV_ADD flags describing the
+ * expected operation. If only %AV_ADD is set, -EEXIST is returned
+ * if the volume already exists. If only %AV_FIND is set, NULL is
+ * returned if the volume does not exist. And if both flags are
+ * set, the helper first tries to find an existing volume, and if
+ * it does not exist it creates a new one.
+ * @created: in value used to inform the caller whether it"s a newly created
+ * volume or not.
+ *
+ * This function returns a pointer to a volume description or an ERR_PTR if
+ * the operation failed. It can also return NULL if only %AV_FIND is set and
+ * the volume does not exist.
+ */
+static struct ubi_ainf_volume *find_or_add_av(struct ubi_attach_info *ai,
+ int vol_id, unsigned int flags,
+ bool *created)
+{
+ struct ubi_ainf_volume *av;
+ struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
+
+ /* 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) {
+ *created = false;
+
+ if (!(flags & AV_FIND))
+ return ERR_PTR(-EEXIST);
+
+ return av;
+ }
+
+ if (vol_id > av->vol_id)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+
+ if (!(flags & AV_ADD))
+ return NULL;
+
+ /* The volume is absent - add it */
+ av = kzalloc(sizeof(*av), GFP_KERNEL);
+ if (!av)
+ return ERR_PTR(-ENOMEM);
+
+ av->vol_id = vol_id;
+
+ 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;
+ *created = true;
+ dbg_bld("added volume %d", vol_id);
+ return av;
+}
+
+/**
+ * ubi_find_or_add_av - search for a volume in the attaching information and
+ * add one if it does not exist.
+ * @ai: attaching information
+ * @vol_id: the requested volume ID
+ * @created: whether the volume has been created or not
+ *
+ * This function returns a pointer to the new volume description or an
+ * ERR_PTR if the operation failed.
+ */
+static struct ubi_ainf_volume *ubi_find_or_add_av(struct ubi_attach_info *ai,
+ int vol_id, bool *created)
+{
+ return find_or_add_av(ai, vol_id, AV_FIND_OR_ADD, created);
+}
+
+/**
+ * ubi_alloc_aeb - allocate an aeb element
+ * @ai: attaching information
+ * @pnum: physical eraseblock number
+ * @ec: erase counter of the physical eraseblock
+ *
+ * Allocate an aeb object and initialize the pnum and ec information.
+ * vol_id and lnum are set to UBI_UNKNOWN, and the other fields are
+ * initialized to zero.
+ * Note that the element is not added in any list or RB tree.
+ */
+struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum,
+ int ec)
+{
+ struct ubi_ainf_peb *aeb;
+
+ aeb = kmem_cache_zalloc(ai->aeb_slab_cache, GFP_KERNEL);
+ if (!aeb)
+ return NULL;
+
+ aeb->pnum = pnum;
+ aeb->ec = ec;
+ aeb->vol_id = UBI_UNKNOWN;
+ aeb->lnum = UBI_UNKNOWN;
+
+ return aeb;
+}
+
+/**
+ * ubi_free_aeb - free an aeb element
+ * @ai: attaching information
+ * @aeb: the element to free
+ *
+ * Free an aeb object. The caller must have removed the element from any list
+ * or RB tree.
+ */
+void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb)
+{
+ kmem_cache_free(ai->aeb_slab_cache, aeb);
+}
+
+/**
+ * add_to_list - add physical eraseblock to a list.
+ * @ai: attaching information
+ * @pnum: physical eraseblock number to add
+ * @vol_id: the last used volume id for the PEB
+ * @lnum: the last used LEB number for the PEB
+ * @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.
+ * It stores the @lnum and @vol_id alongside, which can both be
+ * %UBI_UNKNOWN if they are not available, not readable, or not assigned.
+ * 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 vol_id,
+ int lnum, 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 = ubi_alloc_aeb(ai, pnum, ec);
+ if (!aeb)
+ return -ENOMEM;
+
+ aeb->vol_id = vol_id;
+ aeb->lnum = lnum;
+ 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 = ubi_alloc_aeb(ai, pnum, ec);
+ if (!aeb)
+ return -ENOMEM;
+
+ ai->corr_peb_count += 1;
+ list_add(&aeb->u.list, &ai->corr);
+ return 0;
+}
+
+/**
+ * add_fastmap - add a Fastmap related physical eraseblock.
+ * @ai: attaching information
+ * @pnum: physical eraseblock number the VID header came from
+ * @vid_hdr: the volume identifier header
+ * @ec: erase counter of the physical eraseblock
+ *
+ * This function allocates a 'struct ubi_ainf_peb' object for a Fastamp
+ * physical eraseblock @pnum and adds it to the 'fastmap' list.
+ * Such blocks can be Fastmap super and data blocks from both the most
+ * recent Fastmap we're attaching from or from old Fastmaps which will
+ * be erased.
+ */
+static int add_fastmap(struct ubi_attach_info *ai, int pnum,
+ struct ubi_vid_hdr *vid_hdr, int ec)
+{
+ struct ubi_ainf_peb *aeb;
+
+ aeb = ubi_alloc_aeb(ai, pnum, ec);
+ if (!aeb)
+ return -ENOMEM;
+
+ aeb->vol_id = be32_to_cpu(vid_hdr->vol_id);
+ aeb->sqnum = be64_to_cpu(vid_hdr->sqnum);
+ list_add(&aeb->u.list, &ai->fastmap);
+
+ dbg_bld("add to fastmap list: PEB %d, vol_id %d, sqnum: %llu", pnum,
+ aeb->vol_id, aeb->sqnum);
+
+ return 0;
+}
+
+/**
+ * validate_vid_hdr - check volume identifier header.
+ * @ubi: UBI device description object
+ * @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_device *ubi,
+ 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(ubi, "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(ubi, "inconsistent vol_type");
+ goto bad;
+ }
+
+ if (used_ebs != av->used_ebs) {
+ ubi_err(ubi, "inconsistent used_ebs");
+ goto bad;
+ }
+
+ if (data_pad != av->data_pad) {
+ ubi_err(ubi, "inconsistent data_pad");
+ goto bad;
+ }
+ }
+
+ return 0;
+
+bad:
+ ubi_err(ubi, "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;
+ bool created;
+
+ ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
+
+ av = ubi_find_or_add_av(ai, vol_id, &created);
+ if (IS_ERR(av) || !created)
+ return av;
+
+ 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;
+
+ return av;
+}
+
+/**
+ * ubi_compare_lebs - find out which logical eraseblock is newer.
+ * @ubi: UBI device description object
+ * @aeb: first logical eraseblock to compare
+ * @pnum: physical eraseblock number of the second logical eraseblock to
+ * 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.
+ */
+int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
+ int pnum, const struct ubi_vid_hdr *vid_hdr)
+{
+ int len, err, second_is_newer, bitflips = 0, corrupted = 0;
+ uint32_t data_crc, crc;
+ struct ubi_vid_io_buf *vidb = 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(ubi, "unsupported on-flash UBI format");
+ 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;
+ }
+
+ vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
+ if (!vidb)
+ return -ENOMEM;
+
+ pnum = aeb->pnum;
+ err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 0);
+ if (err) {
+ if (err == UBI_IO_BITFLIPS)
+ bitflips = 1;
+ else {
+ ubi_err(ubi, "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 = ubi_get_vid_hdr(vidb);
+ }
+
+ /* Read the data of the copy and check the CRC */
+
+ len = be32_to_cpu(vid_hdr->data_size);
+
+ mutex_lock(&ubi->buf_mutex);
+ err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, len);
+ if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
+ goto out_unlock;
+
+ data_crc = be32_to_cpu(vid_hdr->data_crc);
+ crc = crc32(UBI_CRC32_INIT, ubi->peb_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;
+ }
+ mutex_unlock(&ubi->buf_mutex);
+
+ ubi_free_vid_buf(vidb);
+
+ 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_unlock:
+ mutex_unlock(&ubi->buf_mutex);
+out_free_vidh:
+ ubi_free_vid_buf(vidb);
+ 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
+ * 'ubi_compare_lebs()'. In other words, we attach old clean
+ * images, but refuse attaching old images with duplicated
+ * logical eraseblocks because there was an unclean reboot.
+ */
+ if (aeb->sqnum == sqnum && sqnum != 0) {
+ ubi_err(ubi, "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 = ubi_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(ubi, vid_hdr, av, pnum);
+ if (err)
+ return err;
+
+ err = add_to_list(ai, aeb->pnum, aeb->vol_id,
+ aeb->lnum, aeb->ec, cmp_res & 4,
+ &ai->erase);
+ if (err)
+ return err;
+
+ aeb->ec = ec;
+ aeb->pnum = pnum;
+ aeb->vol_id = vol_id;
+ aeb->lnum = lnum;
+ 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, vol_id, lnum, 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(ubi, vid_hdr, av, pnum);
+ if (err)
+ return err;
+
+ aeb = ubi_alloc_aeb(ai, pnum, ec);
+ if (!aeb)
+ return -ENOMEM;
+
+ aeb->vol_id = vol_id;
+ 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_add_av - add volume to the attaching information.
+ * @ai: attaching information
+ * @vol_id: the requested volume ID
+ *
+ * This function returns a pointer to the new volume description or an
+ * ERR_PTR if the operation failed.
+ */
+struct ubi_ainf_volume *ubi_add_av(struct ubi_attach_info *ai, int vol_id)
+{
+ bool created;
+
+ return find_or_add_av(ai, vol_id, AV_ADD, &created);
+}
+
+/**
+ * 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)
+{
+ bool created;
+
+ return find_or_add_av((struct ubi_attach_info *)ai, vol_id, AV_FIND,
+ &created);
+}
+
+static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av,
+ struct list_head *list);
+
+/**
+ * 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)
+{
+ dbg_bld("remove attaching information about volume %d", av->vol_id);
+
+ rb_erase(&av->rb, &ai->volumes);
+ destroy_av(ai, av, &ai->erase);
+ 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(ubi, "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(ubi, "no free eraseblocks");
+ return ERR_PTR(-ENOSPC);
+}
+
+/**
+ * check_corruption - check the data area of PEB.
+ * @ubi: UBI device description object
+ * @vid_hdr: the (corrupted) VID header of this PEB
+ * @pnum: the physical eraseblock number to check
+ *
+ * This is a helper function which is used to distinguish between VID header
+ * 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(ubi, "PEB %d contains corrupted VID header, and the data does not contain all 0xFF",
+ pnum);
+ ubi_err(ubi, "this may be a non-UBI PEB or a severe VID header corruption which requires manual inspection");
+ ubi_dump_vid_hdr(vid_hdr);
+ pr_err("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;
+}
+
+static bool vol_ignored(int vol_id)
+{
+ switch (vol_id) {
+ case UBI_LAYOUT_VOLUME_ID:
+ return true;
+ }
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+ return ubi_is_fm_vol(vol_id);
+#else
+ return false;
+#endif
+}
+
+/**
+ * scan_peb - scan and process UBI headers of a PEB.
+ * @ubi: UBI device description object
+ * @ai: attaching information
+ * @pnum: the physical eraseblock number
+ * @fast: true if we're scanning for a Fastmap
+ *
+ * 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, bool fast)
+{
+ struct ubi_ec_hdr *ech = ai->ech;
+ struct ubi_vid_io_buf *vidb = ai->vidb;
+ struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb);
+ long long ec;
+ int err, bitflips = 0, vol_id = -1, 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, UBI_UNKNOWN,
+ UBI_UNKNOWN, 0, &ai->erase);
+ case UBI_IO_FF_BITFLIPS:
+ ai->empty_peb_count += 1;
+ return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
+ 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, "'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(ubi, "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(ubi, "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)
+ ubi->image_seq = image_seq;
+ if (image_seq && ubi->image_seq != image_seq) {
+ ubi_err(ubi, "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, vidb, 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 we're facing a bad VID header we have to drop *all*
+ * Fastmap data structures we find. The most recent Fastmap
+ * could be bad and therefore there is a chance that we attach
+ * from an old one. On a fine MTD stack a PEB must not render
+ * bad all of a sudden, but the reality is different.
+ * So, let's be paranoid and help finding the root cause by
+ * falling back to scanning mode instead of attaching with a
+ * bad EBA table and cause data corruption which is hard to
+ * analyze.
+ */
+ if (fast)
+ ai->force_full_scan = 1;
+
+ 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, UBI_UNKNOWN,
+ UBI_UNKNOWN, 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, UBI_UNKNOWN, UBI_UNKNOWN,
+ ec, 1, &ai->erase);
+ if (err)
+ return err;
+ goto adjust_mean_ec;
+ case UBI_IO_FF:
+ if (ec_err || bitflips)
+ err = add_to_list(ai, pnum, UBI_UNKNOWN,
+ UBI_UNKNOWN, ec, 1, &ai->erase);
+ else
+ err = add_to_list(ai, pnum, UBI_UNKNOWN,
+ UBI_UNKNOWN, ec, 0, &ai->free);
+ if (err)
+ return err;
+ goto adjust_mean_ec;
+ default:
+ ubi_err(ubi, "'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_ignored(vol_id)) {
+ int lnum = be32_to_cpu(vidh->lnum);
+
+ /* Unsupported internal volume */
+ switch (vidh->compat) {
+ case UBI_COMPAT_DELETE:
+ ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it",
+ vol_id, lnum);
+
+ err = add_to_list(ai, pnum, vol_id, lnum,
+ ec, 1, &ai->erase);
+ if (err)
+ return err;
+ return 0;
+
+ case UBI_COMPAT_RO:
+ ubi_msg(ubi, "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(ubi, "\"preserve\" compatible internal volume %d:%d found",
+ vol_id, lnum);
+ err = add_to_list(ai, pnum, vol_id, lnum,
+ ec, 0, &ai->alien);
+ if (err)
+ return err;
+ return 0;
+
+ case UBI_COMPAT_REJECT:
+ ubi_err(ubi, "incompatible internal volume %d:%d found",
+ vol_id, lnum);
+ return -EINVAL;
+ }
+ }
+
+ if (ec_err)
+ ubi_warn(ubi, "valid VID header but corrupted EC header at PEB %d",
+ pnum);
+
+ if (ubi_is_fm_vol(vol_id))
+ err = add_fastmap(ai, pnum, vidh, ec);
+ else
+ 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(ubi, "%d PEBs are corrupted and preserved",
+ ai->corr_peb_count);
+ pr_err("Corrupted PEBs are:");
+ list_for_each_entry(aeb, &ai->corr, u.list)
+ pr_cont(" %d", aeb->pnum);
+ pr_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(ubi, "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(ubi, "empty MTD device detected");
+ get_random_bytes(&ubi->image_seq,
+ sizeof(ubi->image_seq));
+ } else {
+ ubi_err(ubi, "MTD device is not UBI-formatted and possibly contains non-UBI data - refusing it");
+ return -EINVAL;
+ }
+
+ }
+
+ return 0;
+}
+
+/**
+ * destroy_av - free volume attaching information.
+ * @av: volume attaching information
+ * @ai: attaching information
+ * @list: put the aeb elements in there if !NULL, otherwise free them
+ *
+ * This function destroys the volume attaching information.
+ */
+static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av,
+ struct list_head *list)
+{
+ 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;
+ }
+
+ if (list)
+ list_add_tail(&aeb->u.list, list);
+ else
+ ubi_free_aeb(ai, aeb);
+ }
+ }
+ kfree(av);
+}
+
+/**
+ * destroy_ai - destroy attaching information.
+ * @ai: attaching information
+ */
+static void destroy_ai(struct ubi_attach_info *ai)
+{
+ struct ubi_ainf_peb *aeb, *aeb_tmp;
+ struct ubi_ainf_volume *av;
+ struct rb_node *rb;
+
+ list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {
+ list_del(&aeb->u.list);
+ ubi_free_aeb(ai, aeb);
+ }
+ list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
+ list_del(&aeb->u.list);
+ ubi_free_aeb(ai, aeb);
+ }
+ list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
+ list_del(&aeb->u.list);
+ ubi_free_aeb(ai, aeb);
+ }
+ list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
+ list_del(&aeb->u.list);
+ ubi_free_aeb(ai, aeb);
+ }
+ list_for_each_entry_safe(aeb, aeb_tmp, &ai->fastmap, u.list) {
+ list_del(&aeb->u.list);
+ ubi_free_aeb(ai, 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, NULL);
+ }
+ }
+
+ kmem_cache_destroy(ai->aeb_slab_cache);
+ kfree(ai);
+}
+
+/**
+ * scan_all - scan entire MTD device.
+ * @ubi: UBI device description object
+ * @ai: attach info object
+ * @start: start scanning at this PEB
+ *
+ * This function does full scanning of an MTD device and returns complete
+ * information about it in form of a "struct ubi_attach_info" object. In case
+ * of failure, an error code is returned.
+ */
+static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
+ int start)
+{
+ int err, pnum;
+ struct rb_node *rb1, *rb2;
+ struct ubi_ainf_volume *av;
+ struct ubi_ainf_peb *aeb;
+
+ err = -ENOMEM;
+
+ ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ if (!ai->ech)
+ return err;
+
+ ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
+ if (!ai->vidb)
+ goto out_ech;
+
+ for (pnum = start; pnum < ubi->peb_count; pnum++) {
+ cond_resched();
+
+ dbg_gen("process PEB %d", pnum);
+ err = scan_peb(ubi, ai, pnum, false);
+ if (err < 0)
+ goto out_vidh;
+ }
+
+ ubi_msg(ubi, "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_buf(ai->vidb);
+ kfree(ai->ech);
+
+ return 0;
+
+out_vidh:
+ ubi_free_vid_buf(ai->vidb);
+out_ech:
+ kfree(ai->ech);
+ return err;
+}
+
+static struct ubi_attach_info *alloc_ai(void)
+{
+ struct ubi_attach_info *ai;
+
+ ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
+ if (!ai)
+ return ai;
+
+ INIT_LIST_HEAD(&ai->corr);
+ INIT_LIST_HEAD(&ai->free);
+ INIT_LIST_HEAD(&ai->erase);
+ INIT_LIST_HEAD(&ai->alien);
+ INIT_LIST_HEAD(&ai->fastmap);
+ ai->volumes = RB_ROOT;
+ ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
+ sizeof(struct ubi_ainf_peb),
+ 0, 0, NULL);
+ if (!ai->aeb_slab_cache) {
+ kfree(ai);
+ ai = NULL;
+ }
+
+ return ai;
+}
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+
+/**
+ * scan_fast - try to find a fastmap and attach from it.
+ * @ubi: UBI device description object
+ * @ai: attach info object
+ *
+ * Returns 0 on success, negative return values indicate an internal
+ * error.
+ * UBI_NO_FASTMAP denotes that no fastmap was found.
+ * UBI_BAD_FASTMAP denotes that the found fastmap was invalid.
+ */
+static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
+{
+ int err, pnum;
+ struct ubi_attach_info *scan_ai;
+
+ err = -ENOMEM;
+
+ scan_ai = alloc_ai();
+ if (!scan_ai)
+ goto out;
+
+ scan_ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ if (!scan_ai->ech)
+ goto out_ai;
+
+ scan_ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
+ if (!scan_ai->vidb)
+ goto out_ech;
+
+ for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
+ cond_resched();
+
+ dbg_gen("process PEB %d", pnum);
+ err = scan_peb(ubi, scan_ai, pnum, true);
+ if (err < 0)
+ goto out_vidh;
+ }
+
+ ubi_free_vid_buf(scan_ai->vidb);
+ kfree(scan_ai->ech);
+
+ if (scan_ai->force_full_scan)
+ err = UBI_NO_FASTMAP;
+ else
+ err = ubi_scan_fastmap(ubi, *ai, scan_ai);
+
+ if (err) {
+ /*
+ * Didn't attach via fastmap, do a full scan but reuse what
+ * we've aready scanned.
+ */
+ destroy_ai(*ai);
+ *ai = scan_ai;
+ } else
+ destroy_ai(scan_ai);
+
+ return err;
+
+out_vidh:
+ ubi_free_vid_buf(scan_ai->vidb);
+out_ech:
+ kfree(scan_ai->ech);
+out_ai:
+ destroy_ai(scan_ai);
+out:
+ return err;
+}
+
+#endif
+
+/**
+ * ubi_attach - attach an MTD device.
+ * @ubi: UBI device descriptor
+ * @force_scan: if set to non-zero attach by scanning
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_attach(struct ubi_device *ubi, int force_scan)
+{
+ int err;
+ struct ubi_attach_info *ai;
+
+ ai = alloc_ai();
+ if (!ai)
+ return -ENOMEM;
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+ /* On small flash devices we disable fastmap in any case. */
+ if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) {
+ ubi->fm_disabled = 1;
+ force_scan = 1;
+ }
+
+ if (force_scan)
+ err = scan_all(ubi, ai, 0);
+ else {
+ err = scan_fast(ubi, &ai);
+ if (err > 0 || mtd_is_eccerr(err)) {
+ if (err != UBI_NO_FASTMAP) {
+ destroy_ai(ai);
+ ai = alloc_ai();
+ if (!ai)
+ return -ENOMEM;
+
+ err = scan_all(ubi, ai, 0);
+ } else {
+ err = scan_all(ubi, ai, UBI_FM_MAX_START);
+ }
+ }
+ }
+#else
+ err = scan_all(ubi, ai, 0);
+#endif
+ if (err)
+ goto out_ai;
+
+ ubi->bad_peb_count = ai->bad_peb_count;
+ ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
+ ubi->corr_peb_count = ai->corr_peb_count;
+ ubi->max_ec = ai->max_ec;
+ ubi->mean_ec = ai->mean_ec;
+ dbg_gen("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;
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+ if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) {
+ struct ubi_attach_info *scan_ai;
+
+ scan_ai = alloc_ai();
+ if (!scan_ai) {
+ err = -ENOMEM;
+ goto out_wl;
+ }
+
+ err = scan_all(ubi, scan_ai, 0);
+ if (err) {
+ destroy_ai(scan_ai);
+ goto out_wl;
+ }
+
+ err = self_check_eba(ubi, ai, scan_ai);
+ destroy_ai(scan_ai);
+
+ if (err)
+ goto out_wl;
+ }
+#endif
+
+ destroy_ai(ai);
+ return 0;
+
+out_wl:
+ ubi_wl_close(ubi);
+out_vtbl:
+ ubi_free_internal_volumes(ubi);
+ vfree(ubi->vtbl);
+out_ai:
+ destroy_ai(ai);
+ return err;
+}
+
+/**
+ * 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)
+{
+ struct ubi_vid_io_buf *vidb = ai->vidb;
+ struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb);
+ 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(ubi))
+ 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(ubi, "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(ubi, "negative values");
+ goto bad_av;
+ }
+
+ if (av->vol_id >= UBI_MAX_VOLUMES &&
+ av->vol_id < UBI_INTERNAL_VOL_START) {
+ ubi_err(ubi, "bad vol_id");
+ goto bad_av;
+ }
+
+ if (av->vol_id > ai->highest_vol_id) {
+ ubi_err(ubi, "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(ubi, "bad vol_type");
+ goto bad_av;
+ }
+
+ if (av->data_pad > ubi->leb_size / 2) {
+ ubi_err(ubi, "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(ubi, "negative values");
+ goto bad_aeb;
+ }
+
+ if (aeb->ec < ai->min_ec) {
+ ubi_err(ubi, "bad ai->min_ec (%d), %d found",
+ ai->min_ec, aeb->ec);
+ goto bad_aeb;
+ }
+
+ if (aeb->ec > ai->max_ec) {
+ ubi_err(ubi, "bad ai->max_ec (%d), %d found",
+ ai->max_ec, aeb->ec);
+ goto bad_aeb;
+ }
+
+ if (aeb->pnum >= ubi->peb_count) {
+ ubi_err(ubi, "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(ubi, "bad lnum or used_ebs");
+ goto bad_aeb;
+ }
+ } else {
+ if (av->used_ebs != 0) {
+ ubi_err(ubi, "non-zero used_ebs");
+ goto bad_aeb;
+ }
+ }
+
+ if (aeb->lnum > av->highest_lnum) {
+ ubi_err(ubi, "incorrect highest_lnum or lnum");
+ goto bad_aeb;
+ }
+ }
+
+ if (av->leb_count != leb_count) {
+ ubi_err(ubi, "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(ubi, "bad highest_lnum");
+ goto bad_aeb;
+ }
+ }
+
+ if (vols_found != ai->vols_found) {
+ ubi_err(ubi, "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, vidb, 1);
+ if (err && err != UBI_IO_BITFLIPS) {
+ ubi_err(ubi, "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(ubi, "bad vol_type");
+ goto bad_vid_hdr;
+ }
+
+ if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
+ ubi_err(ubi, "bad sqnum %llu", aeb->sqnum);
+ goto bad_vid_hdr;
+ }
+
+ if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
+ ubi_err(ubi, "bad vol_id %d", av->vol_id);
+ goto bad_vid_hdr;
+ }
+
+ if (av->compat != vidh->compat) {
+ ubi_err(ubi, "bad compat %d", vidh->compat);
+ goto bad_vid_hdr;
+ }
+
+ if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
+ ubi_err(ubi, "bad lnum %d", aeb->lnum);
+ goto bad_vid_hdr;
+ }
+
+ if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
+ ubi_err(ubi, "bad used_ebs %d", av->used_ebs);
+ goto bad_vid_hdr;
+ }
+
+ if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
+ ubi_err(ubi, "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(ubi, "bad highest_lnum %d", av->highest_lnum);
+ goto bad_vid_hdr;
+ }
+
+ if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
+ ubi_err(ubi, "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(ubi, "PEB %d is not referred", pnum);
+ err = 1;
+ }
+
+ kfree(buf);
+ if (err)
+ goto out;
+ return 0;
+
+bad_aeb:
+ ubi_err(ubi, "bad attaching information about LEB %d", aeb->lnum);
+ ubi_dump_aeb(aeb, 0);
+ ubi_dump_av(av);
+ goto out;
+
+bad_av:
+ ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
+ ubi_dump_av(av);
+ goto out;
+
+bad_vid_hdr:
+ ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
+ ubi_dump_av(av);
+ ubi_dump_vid_hdr(vidh);
+
+out:
+ dump_stack();
+ return -EINVAL;
+}