[U-Boot] [PATCH] [UBI] Basic Unsorted Block Image (UBI) support v3 (#2)
Kyungmin Park
kmpark at infradead.org
Tue Oct 28 08:47:49 CET 2008
UBI (Latin: "where?") stands for "Unsorted Block Images". It is a volume management system for flash devices which manages multiple logical volumes on a single physical flash device and spreads the I/O load (i.e, wear-leveling) across the whole flash chip.
In a sense, UBI may be compared to the Logical Volume Manager (LVM). Whereas LVM maps logical sectors to physical sectors, UBI maps logical eraseblocks to physical eraseblocks. But besides the mapping, UBI implements global wear-leveling and I/O errors handling.
For more details, Please visit the following URL.
http://www.linux-mtd.infradead.org/doc/ubi.html
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
new file mode 100644
index 0000000..d320562
--- /dev/null
+++ b/drivers/mtd/ubi/eba.c
@@ -0,0 +1,1254 @@
+/*
+ * 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)
+ */
+
+/*
+ * The UBI Eraseblock Association (EBA) unit.
+ *
+ * This unit is responsible for I/O to/from logical eraseblock.
+ *
+ * Although in this implementation the EBA table is fully kept and managed in
+ * RAM, which assumes poor scalability, it might be (partially) maintained on
+ * flash in future implementations.
+ *
+ * The EBA unit implements per-logical eraseblock locking. Before accessing a
+ * logical eraseblock it is locked for reading or writing. The per-logical
+ * eraseblock locking is implemented by means of the lock tree. The lock tree
+ * is an RB-tree which refers all the currently locked logical eraseblocks. The
+ * lock tree elements are &struct ubi_ltree_entry objects. They are indexed by
+ * (@vol_id, @lnum) pairs.
+ *
+ * EBA also maintains the global sequence counter which is incremented each
+ * time a logical eraseblock is mapped to a physical eraseblock and it is
+ * stored in the volume identifier header. This means that each VID header has
+ * a unique sequence number. The sequence number is only increased an we assume
+ * 64 bits is enough to never overflow.
+ */
+
+#ifdef UBI_LINUX
+#include <linux/slab.h>
+#include <linux/crc32.h>
+#include <linux/err.h>
+#endif
+
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+/* Number of physical eraseblocks reserved for atomic LEB change operation */
+#define EBA_RESERVED_PEBS 1
+
+/**
+ * next_sqnum - get next sequence number.
+ * @ubi: UBI device description object
+ *
+ * This function returns next sequence number to use, which is just the current
+ * global sequence counter value. It also increases the global sequence
+ * counter.
+ */
+static unsigned long long next_sqnum(struct ubi_device *ubi)
+{
+ unsigned long long sqnum;
+
+ spin_lock(&ubi->ltree_lock);
+ sqnum = ubi->global_sqnum++;
+ spin_unlock(&ubi->ltree_lock);
+
+ return sqnum;
+}
+
+/**
+ * ubi_get_compat - get compatibility flags of a volume.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ *
+ * This function returns compatibility flags for an internal volume. User
+ * volumes have no compatibility flags, so %0 is returned.
+ */
+static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
+{
+ if (vol_id == UBI_LAYOUT_VOLUME_ID)
+ return UBI_LAYOUT_VOLUME_COMPAT;
+ return 0;
+}
+
+/**
+ * ltree_lookup - look up the lock tree.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function returns a pointer to the corresponding &struct ubi_ltree_entry
+ * object if the logical eraseblock is locked and %NULL if it is not.
+ * @ubi->ltree_lock has to be locked.
+ */
+static struct ubi_ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id,
+ int lnum)
+{
+ struct rb_node *p;
+
+ p = ubi->ltree.rb_node;
+ while (p) {
+ struct ubi_ltree_entry *le;
+
+ le = rb_entry(p, struct ubi_ltree_entry, rb);
+
+ if (vol_id < le->vol_id)
+ p = p->rb_left;
+ else if (vol_id > le->vol_id)
+ p = p->rb_right;
+ else {
+ if (lnum < le->lnum)
+ p = p->rb_left;
+ else if (lnum > le->lnum)
+ p = p->rb_right;
+ else
+ return le;
+ }
+ }
+
+ return NULL;
+}
+
+/**
+ * ltree_add_entry - add new entry to the lock tree.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function adds new entry for logical eraseblock (@vol_id, @lnum) to the
+ * lock tree. If such entry is already there, its usage counter is increased.
+ * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation
+ * failed.
+ */
+static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi,
+ int vol_id, int lnum)
+{
+ struct ubi_ltree_entry *le, *le1, *le_free;
+
+ le = kmalloc(sizeof(struct ubi_ltree_entry), GFP_NOFS);
+ if (!le)
+ return ERR_PTR(-ENOMEM);
+
+ le->users = 0;
+ init_rwsem(&le->mutex);
+ le->vol_id = vol_id;
+ le->lnum = lnum;
+
+ spin_lock(&ubi->ltree_lock);
+ le1 = ltree_lookup(ubi, vol_id, lnum);
+
+ if (le1) {
+ /*
+ * This logical eraseblock is already locked. The newly
+ * allocated lock entry is not needed.
+ */
+ le_free = le;
+ le = le1;
+ } else {
+ struct rb_node **p, *parent = NULL;
+
+ /*
+ * No lock entry, add the newly allocated one to the
+ * @ubi->ltree RB-tree.
+ */
+ le_free = NULL;
+
+ p = &ubi->ltree.rb_node;
+ while (*p) {
+ parent = *p;
+ le1 = rb_entry(parent, struct ubi_ltree_entry, rb);
+
+ if (vol_id < le1->vol_id)
+ p = &(*p)->rb_left;
+ else if (vol_id > le1->vol_id)
+ p = &(*p)->rb_right;
+ else {
+ ubi_assert(lnum != le1->lnum);
+ if (lnum < le1->lnum)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+ }
+
+ rb_link_node(&le->rb, parent, p);
+ rb_insert_color(&le->rb, &ubi->ltree);
+ }
+ le->users += 1;
+ spin_unlock(&ubi->ltree_lock);
+
+ kfree(le_free);
+
+ return le;
+}
+
+/**
+ * leb_read_lock - lock logical eraseblock for reading.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function locks a logical eraseblock for reading. Returns zero in case
+ * of success and a negative error code in case of failure.
+ */
+static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+ struct ubi_ltree_entry *le;
+
+ le = ltree_add_entry(ubi, vol_id, lnum);
+ if (IS_ERR(le))
+ return PTR_ERR(le);
+ down_read(&le->mutex);
+ return 0;
+}
+
+/**
+ * leb_read_unlock - unlock logical eraseblock.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ */
+static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+ int _free = 0;
+ struct ubi_ltree_entry *le;
+
+ spin_lock(&ubi->ltree_lock);
+ le = ltree_lookup(ubi, vol_id, lnum);
+ le->users -= 1;
+ ubi_assert(le->users >= 0);
+ if (le->users == 0) {
+ rb_erase(&le->rb, &ubi->ltree);
+ _free = 1;
+ }
+ spin_unlock(&ubi->ltree_lock);
+
+ up_read(&le->mutex);
+ if (_free)
+ kfree(le);
+}
+
+/**
+ * leb_write_lock - lock logical eraseblock for writing.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function locks a logical eraseblock for writing. Returns zero in case
+ * of success and a negative error code in case of failure.
+ */
+static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+ struct ubi_ltree_entry *le;
+
+ le = ltree_add_entry(ubi, vol_id, lnum);
+ if (IS_ERR(le))
+ return PTR_ERR(le);
+ down_write(&le->mutex);
+ return 0;
+}
+
+/**
+ * leb_write_lock - lock logical eraseblock for writing.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function locks a logical eraseblock for writing if there is no
+ * contention and does nothing if there is contention. Returns %0 in case of
+ * success, %1 in case of contention, and and a negative error code in case of
+ * failure.
+ */
+static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+ int _free;
+ struct ubi_ltree_entry *le;
+
+ le = ltree_add_entry(ubi, vol_id, lnum);
+ if (IS_ERR(le))
+ return PTR_ERR(le);
+ if (down_write_trylock(&le->mutex))
+ return 0;
+
+ /* Contention, cancel */
+ spin_lock(&ubi->ltree_lock);
+ le->users -= 1;
+ ubi_assert(le->users >= 0);
+ if (le->users == 0) {
+ rb_erase(&le->rb, &ubi->ltree);
+ _free = 1;
+ } else
+ _free = 0;
+ spin_unlock(&ubi->ltree_lock);
+ if (_free)
+ kfree(le);
+
+ return 1;
+}
+
+/**
+ * leb_write_unlock - unlock logical eraseblock.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ */
+static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+ int _free;
+ struct ubi_ltree_entry *le;
+
+ spin_lock(&ubi->ltree_lock);
+ le = ltree_lookup(ubi, vol_id, lnum);
+ le->users -= 1;
+ ubi_assert(le->users >= 0);
+ if (le->users == 0) {
+ rb_erase(&le->rb, &ubi->ltree);
+ _free = 1;
+ } else
+ _free = 0;
+ spin_unlock(&ubi->ltree_lock);
+
+ up_write(&le->mutex);
+ if (_free)
+ kfree(le);
+}
+
+/**
+ * ubi_eba_unmap_leb - un-map logical eraseblock.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ *
+ * This function un-maps logical eraseblock @lnum and schedules corresponding
+ * physical eraseblock for erasure. Returns zero in case of success and a
+ * negative error code in case of failure.
+ */
+int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
+ int lnum)
+{
+ int err, pnum, vol_id = vol->vol_id;
+
+ if (ubi->ro_mode)
+ return -EROFS;
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (err)
+ return err;
+
+ pnum = vol->eba_tbl[lnum];
+ if (pnum < 0)
+ /* This logical eraseblock is already unmapped */
+ goto out_unlock;
+
+ dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
+
+ vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
+ err = ubi_wl_put_peb(ubi, pnum, 0);
+
+out_unlock:
+ leb_write_unlock(ubi, vol_id, lnum);
+ return err;
+}
+
+/**
+ * ubi_eba_read_leb - read data.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: buffer to store the read data
+ * @offset: offset from where to read
+ * @len: how many bytes to read
+ * @check: data CRC check flag
+ *
+ * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
+ * bytes. The @check flag only makes sense for static volumes and forces
+ * eraseblock data CRC checking.
+ *
+ * In case of success this function returns zero. In case of a static volume,
+ * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
+ * returned for any volume type if an ECC error was detected by the MTD device
+ * driver. Other negative error cored may be returned in case of other errors.
+ */
+int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
+ void *buf, int offset, int len, int check)
+{
+ int err, pnum, scrub = 0, vol_id = vol->vol_id;
+ struct ubi_vid_hdr *vid_hdr;
+ uint32_t uninitialized_var(crc);
+
+ err = leb_read_lock(ubi, vol_id, lnum);
+ if (err)
+ return err;
+
+ pnum = vol->eba_tbl[lnum];
+ if (pnum < 0) {
+ /*
+ * The logical eraseblock is not mapped, fill the whole buffer
+ * with 0xFF bytes. The exception is static volumes for which
+ * it is an error to read unmapped logical eraseblocks.
+ */
+ dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
+ len, offset, vol_id, lnum);
+ leb_read_unlock(ubi, vol_id, lnum);
+ ubi_assert(vol->vol_type != UBI_STATIC_VOLUME);
+ memset(buf, 0xFF, len);
+ return 0;
+ }
+
+ dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
+ len, offset, vol_id, lnum, pnum);
+
+ if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+ check = 0;
+
+retry:
+ if (check) {
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ if (!vid_hdr) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
+ if (err && err != UBI_IO_BITFLIPS) {
+ if (err > 0) {
+ /*
+ * The header is either absent or corrupted.
+ * The former case means there is a bug -
+ * switch to read-only mode just in case.
+ * The latter case means a real corruption - we
+ * may try to recover data. FIXME: but this is
+ * not implemented.
+ */
+ if (err == UBI_IO_BAD_VID_HDR) {
+ ubi_warn("bad VID header at PEB %d, LEB"
+ "%d:%d", pnum, vol_id, lnum);
+ err = -EBADMSG;
+ } else
+ ubi_ro_mode(ubi);
+ }
+ goto out_free;
+ } else if (err == UBI_IO_BITFLIPS)
+ scrub = 1;
+
+ ubi_assert(lnum < be32_to_cpu(vid_hdr->used_ebs));
+ ubi_assert(len == be32_to_cpu(vid_hdr->data_size));
+
+ crc = be32_to_cpu(vid_hdr->data_crc);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ }
+
+ err = ubi_io_read_data(ubi, buf, pnum, offset, len);
+ if (err) {
+ if (err == UBI_IO_BITFLIPS) {
+ scrub = 1;
+ err = 0;
+ } else if (err == -EBADMSG) {
+ if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+ goto out_unlock;
+ scrub = 1;
+ if (!check) {
+ ubi_msg("force data checking");
+ check = 1;
+ goto retry;
+ }
+ } else
+ goto out_unlock;
+ }
+
+ if (check) {
+ uint32_t crc1 = crc32(UBI_CRC32_INIT, buf, len);
+ if (crc1 != crc) {
+ ubi_warn("CRC error: calculated %#08x, must be %#08x",
+ crc1, crc);
+ err = -EBADMSG;
+ goto out_unlock;
+ }
+ }
+
+ if (scrub)
+ err = ubi_wl_scrub_peb(ubi, pnum);
+
+ leb_read_unlock(ubi, vol_id, lnum);
+ return err;
+
+out_free:
+ ubi_free_vid_hdr(ubi, vid_hdr);
+out_unlock:
+ leb_read_unlock(ubi, vol_id, lnum);
+ return err;
+}
+
+/**
+ * recover_peb - recover from write failure.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock to recover
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ * @buf: data which was not written because of the write failure
+ * @offset: offset of the failed write
+ * @len: how many bytes should have been written
+ *
+ * This function is called in case of a write failure and moves all good data
+ * from the potentially bad physical eraseblock to a good physical eraseblock.
+ * This function also writes the data which was not written due to the failure.
+ * Returns new physical eraseblock number in case of success, and a negative
+ * error code in case of failure.
+ */
+static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
+ const void *buf, int offset, int len)
+{
+ int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0;
+ struct ubi_volume *vol = ubi->volumes[idx];
+ struct ubi_vid_hdr *vid_hdr;
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ if (!vid_hdr)
+ return -ENOMEM;
+
+ mutex_lock(&ubi->buf_mutex);
+
+retry:
+ new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
+ if (new_pnum < 0) {
+ mutex_unlock(&ubi->buf_mutex);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return new_pnum;
+ }
+
+ ubi_msg("recover PEB %d, move data to PEB %d", pnum, new_pnum);
+
+ err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
+ if (err && err != UBI_IO_BITFLIPS) {
+ if (err > 0)
+ err = -EIO;
+ goto out_put;
+ }
+
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
+ if (err)
+ goto write_error;
+
+ data_size = offset + len;
+ memset(ubi->peb_buf1 + offset, 0xFF, len);
+
+ /* Read everything before the area where the write failure happened */
+ if (offset > 0) {
+ err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
+ if (err && err != UBI_IO_BITFLIPS)
+ goto out_put;
+ }
+
+ memcpy(ubi->peb_buf1 + offset, buf, len);
+
+ err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
+ if (err)
+ goto write_error;
+
+ mutex_unlock(&ubi->buf_mutex);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+
+ vol->eba_tbl[lnum] = new_pnum;
+ ubi_wl_put_peb(ubi, pnum, 1);
+
+ ubi_msg("data was successfully recovered");
+ return 0;
+
+out_put:
+ mutex_unlock(&ubi->buf_mutex);
+ ubi_wl_put_peb(ubi, new_pnum, 1);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+
+write_error:
+ /*
+ * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
+ * get another one.
+ */
+ ubi_warn("failed to write to PEB %d", new_pnum);
+ ubi_wl_put_peb(ubi, new_pnum, 1);
+ if (++tries > UBI_IO_RETRIES) {
+ mutex_unlock(&ubi->buf_mutex);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+ }
+ ubi_msg("try again");
+ goto retry;
+}
+
+/**
+ * ubi_eba_write_leb - write data to dynamic volume.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: the data to write
+ * @offset: offset within the logical eraseblock where to write
+ * @len: how many bytes to write
+ * @dtype: data type
+ *
+ * This function writes data to logical eraseblock @lnum of a dynamic volume
+ * @vol. Returns zero in case of success and a negative error code in case
+ * of failure. In case of error, it is possible that something was still
+ * written to the flash media, but may be some garbage.
+ */
+int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
+ const void *buf, int offset, int len, int dtype)
+{
+ int err, pnum, tries = 0, vol_id = vol->vol_id;
+ struct ubi_vid_hdr *vid_hdr;
+
+ if (ubi->ro_mode)
+ return -EROFS;
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (err)
+ return err;
+
+ pnum = vol->eba_tbl[lnum];
+ if (pnum >= 0) {
+ dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
+ len, offset, vol_id, lnum, pnum);
+
+ err = ubi_io_write_data(ubi, buf, pnum, offset, len);
+ if (err) {
+ ubi_warn("failed to write data to PEB %d", pnum);
+ if (err == -EIO && ubi->bad_allowed)
+ err = recover_peb(ubi, pnum, vol_id, lnum, buf,
+ offset, len);
+ if (err)
+ ubi_ro_mode(ubi);
+ }
+ leb_write_unlock(ubi, vol_id, lnum);
+ return err;
+ }
+
+ /*
+ * The logical eraseblock is not mapped. We have to get a free physical
+ * eraseblock and write the volume identifier header there first.
+ */
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ if (!vid_hdr) {
+ leb_write_unlock(ubi, vol_id, lnum);
+ return -ENOMEM;
+ }
+
+ vid_hdr->vol_type = UBI_VID_DYNAMIC;
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ vid_hdr->vol_id = cpu_to_be32(vol_id);
+ vid_hdr->lnum = cpu_to_be32(lnum);
+ vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+ vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
+
+retry:
+ pnum = ubi_wl_get_peb(ubi, dtype);
+ if (pnum < 0) {
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ leb_write_unlock(ubi, vol_id, lnum);
+ return pnum;
+ }
+
+ dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
+ len, offset, vol_id, lnum, pnum);
+
+ err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
+ if (err) {
+ ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
+ vol_id, lnum, pnum);
+ goto write_error;
+ }
+
+ if (len) {
+ err = ubi_io_write_data(ubi, buf, pnum, offset, len);
+ if (err) {
+ ubi_warn("failed to write %d bytes at offset %d of "
+ "LEB %d:%d, PEB %d", len, offset, vol_id,
+ lnum, pnum);
+ goto write_error;
+ }
+ }
+
+ vol->eba_tbl[lnum] = pnum;
+
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return 0;
+
+write_error:
+ if (err != -EIO || !ubi->bad_allowed) {
+ ubi_ro_mode(ubi);
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+ }
+
+ /*
+ * Fortunately, this is the first write operation to this physical
+ * eraseblock, so just put it and request a new one. We assume that if
+ * this physical eraseblock went bad, the erase code will handle that.
+ */
+ err = ubi_wl_put_peb(ubi, pnum, 1);
+ if (err || ++tries > UBI_IO_RETRIES) {
+ ubi_ro_mode(ubi);
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+ }
+
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ ubi_msg("try another PEB");
+ goto retry;
+}
+
+/**
+ * ubi_eba_write_leb_st - write data to static volume.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: data to write
+ * @len: how many bytes to write
+ * @dtype: data type
+ * @used_ebs: how many logical eraseblocks will this volume contain
+ *
+ * This function writes data to logical eraseblock @lnum of static volume
+ * @vol. The @used_ebs argument should contain total number of logical
+ * eraseblock in this static volume.
+ *
+ * When writing to the last logical eraseblock, the @len argument doesn't have
+ * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
+ * to the real data size, although the @buf buffer has to contain the
+ * alignment. In all other cases, @len has to be aligned.
+ *
+ * It is prohibited to write more then once to logical eraseblocks of static
+ * volumes. This function returns zero in case of success and a negative error
+ * code in case of failure.
+ */
+int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
+ int lnum, const void *buf, int len, int dtype,
+ int used_ebs)
+{
+ int err, pnum, tries = 0, data_size = len, vol_id = vol->vol_id;
+ struct ubi_vid_hdr *vid_hdr;
+ uint32_t crc;
+
+ if (ubi->ro_mode)
+ return -EROFS;
+
+ if (lnum == used_ebs - 1)
+ /* If this is the last LEB @len may be unaligned */
+ len = ALIGN(data_size, ubi->min_io_size);
+ else
+ ubi_assert(!(len & (ubi->min_io_size - 1)));
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ if (!vid_hdr)
+ return -ENOMEM;
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (err) {
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+ }
+
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ vid_hdr->vol_id = cpu_to_be32(vol_id);
+ vid_hdr->lnum = cpu_to_be32(lnum);
+ vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+ vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
+
+ crc = crc32(UBI_CRC32_INIT, buf, data_size);
+ vid_hdr->vol_type = UBI_VID_STATIC;
+ vid_hdr->data_size = cpu_to_be32(data_size);
+ vid_hdr->used_ebs = cpu_to_be32(used_ebs);
+ vid_hdr->data_crc = cpu_to_be32(crc);
+
+retry:
+ pnum = ubi_wl_get_peb(ubi, dtype);
+ if (pnum < 0) {
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ leb_write_unlock(ubi, vol_id, lnum);
+ return pnum;
+ }
+
+ dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
+ len, vol_id, lnum, pnum, used_ebs);
+
+ err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
+ if (err) {
+ ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
+ vol_id, lnum, pnum);
+ goto write_error;
+ }
+
+ err = ubi_io_write_data(ubi, buf, pnum, 0, len);
+ if (err) {
+ ubi_warn("failed to write %d bytes of data to PEB %d",
+ len, pnum);
+ goto write_error;
+ }
+
+ ubi_assert(vol->eba_tbl[lnum] < 0);
+ vol->eba_tbl[lnum] = pnum;
+
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return 0;
+
+write_error:
+ if (err != -EIO || !ubi->bad_allowed) {
+ /*
+ * This flash device does not admit of bad eraseblocks or
+ * something nasty and unexpected happened. Switch to read-only
+ * mode just in case.
+ */
+ ubi_ro_mode(ubi);
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+ }
+
+ err = ubi_wl_put_peb(ubi, pnum, 1);
+ if (err || ++tries > UBI_IO_RETRIES) {
+ ubi_ro_mode(ubi);
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+ }
+
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ ubi_msg("try another PEB");
+ goto retry;
+}
+
+/*
+ * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: data to write
+ * @len: how many bytes to write
+ * @dtype: data type
+ *
+ * This function changes the contents of a logical eraseblock atomically. @buf
+ * has to contain new logical eraseblock data, and @len - the length of the
+ * data, which has to be aligned. This function guarantees that in case of an
+ * unclean reboot the old contents is preserved. Returns zero in case of
+ * success and a negative error code in case of failure.
+ *
+ * UBI reserves one LEB for the "atomic LEB change" operation, so only one
+ * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
+ */
+int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
+ int lnum, const void *buf, int len, int dtype)
+{
+ int err, pnum, tries = 0, vol_id = vol->vol_id;
+ struct ubi_vid_hdr *vid_hdr;
+ uint32_t crc;
+
+ if (ubi->ro_mode)
+ return -EROFS;
+
+ if (len == 0) {
+ /*
+ * Special case when data length is zero. In this case the LEB
+ * has to be unmapped and mapped somewhere else.
+ */
+ err = ubi_eba_unmap_leb(ubi, vol, lnum);
+ if (err)
+ return err;
+ return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
+ }
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ if (!vid_hdr)
+ return -ENOMEM;
+
+ mutex_lock(&ubi->alc_mutex);
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (err)
+ goto out_mutex;
+
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ vid_hdr->vol_id = cpu_to_be32(vol_id);
+ vid_hdr->lnum = cpu_to_be32(lnum);
+ vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+ vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
+
+ crc = crc32(UBI_CRC32_INIT, buf, len);
+ vid_hdr->vol_type = UBI_VID_DYNAMIC;
+ vid_hdr->data_size = cpu_to_be32(len);
+ vid_hdr->copy_flag = 1;
+ vid_hdr->data_crc = cpu_to_be32(crc);
+
+retry:
+ pnum = ubi_wl_get_peb(ubi, dtype);
+ if (pnum < 0) {
+ err = pnum;
+ goto out_leb_unlock;
+ }
+
+ dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
+ vol_id, lnum, vol->eba_tbl[lnum], pnum);
+
+ err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
+ if (err) {
+ ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
+ vol_id, lnum, pnum);
+ goto write_error;
+ }
+
+ err = ubi_io_write_data(ubi, buf, pnum, 0, len);
+ if (err) {
+ ubi_warn("failed to write %d bytes of data to PEB %d",
+ len, pnum);
+ goto write_error;
+ }
+
+ if (vol->eba_tbl[lnum] >= 0) {
+ err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1);
+ if (err)
+ goto out_leb_unlock;
+ }
+
+ vol->eba_tbl[lnum] = pnum;
+
+out_leb_unlock:
+ leb_write_unlock(ubi, vol_id, lnum);
+out_mutex:
+ mutex_unlock(&ubi->alc_mutex);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+
+write_error:
+ if (err != -EIO || !ubi->bad_allowed) {
+ /*
+ * This flash device does not admit of bad eraseblocks or
+ * something nasty and unexpected happened. Switch to read-only
+ * mode just in case.
+ */
+ ubi_ro_mode(ubi);
+ goto out_leb_unlock;
+ }
+
+ err = ubi_wl_put_peb(ubi, pnum, 1);
+ if (err || ++tries > UBI_IO_RETRIES) {
+ ubi_ro_mode(ubi);
+ goto out_leb_unlock;
+ }
+
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ ubi_msg("try another PEB");
+ goto retry;
+}
+
+/**
+ * ubi_eba_copy_leb - copy logical eraseblock.
+ * @ubi: UBI device description object
+ * @from: physical eraseblock number from where to copy
+ * @to: physical eraseblock number where to copy
+ * @vid_hdr: VID header of the @from physical eraseblock
+ *
+ * This function copies logical eraseblock from physical eraseblock @from to
+ * physical eraseblock @to. The @vid_hdr buffer may be changed by this
+ * function. Returns:
+ * o %0 in case of success;
+ * o %1 if the operation was canceled and should be tried later (e.g.,
+ * because a bit-flip was detected at the target PEB);
+ * o %2 if the volume is being deleted and this LEB should not be moved.
+ */
+int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
+ struct ubi_vid_hdr *vid_hdr)
+{
+ int err, vol_id, lnum, data_size, aldata_size, idx;
+ struct ubi_volume *vol;
+ uint32_t crc;
+
+ vol_id = be32_to_cpu(vid_hdr->vol_id);
+ lnum = be32_to_cpu(vid_hdr->lnum);
+
+ dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to);
+
+ if (vid_hdr->vol_type == UBI_VID_STATIC) {
+ data_size = be32_to_cpu(vid_hdr->data_size);
+ aldata_size = ALIGN(data_size, ubi->min_io_size);
+ } else
+ data_size = aldata_size =
+ ubi->leb_size - be32_to_cpu(vid_hdr->data_pad);
+
+ idx = vol_id2idx(ubi, vol_id);
+ spin_lock(&ubi->volumes_lock);
+ /*
+ * Note, we may race with volume deletion, which means that the volume
+ * this logical eraseblock belongs to might be being deleted. Since the
+ * volume deletion unmaps all the volume's logical eraseblocks, it will
+ * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
+ */
+ vol = ubi->volumes[idx];
+ if (!vol) {
+ /* No need to do further work, cancel */
+ dbg_eba("volume %d is being removed, cancel", vol_id);
+ spin_unlock(&ubi->volumes_lock);
+ return 2;
+ }
+ spin_unlock(&ubi->volumes_lock);
+
+ /*
+ * We do not want anybody to write to this logical eraseblock while we
+ * are moving it, so lock it.
+ *
+ * Note, we are using non-waiting locking here, because we cannot sleep
+ * on the LEB, since it may cause deadlocks. Indeed, imagine a task is
+ * unmapping the LEB which is mapped to the PEB we are going to move
+ * (@from). This task locks the LEB and goes sleep in the
+ * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
+ * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
+ * LEB is already locked, we just do not move it and return %1.
+ */
+ err = leb_write_trylock(ubi, vol_id, lnum);
+ if (err) {
+ dbg_eba("contention on LEB %d:%d, cancel", vol_id, lnum);
+ return err;
+ }
+
+ /*
+ * The LEB might have been put meanwhile, and the task which put it is
+ * probably waiting on @ubi->move_mutex. No need to continue the work,
+ * cancel it.
+ */
+ if (vol->eba_tbl[lnum] != from) {
+ dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
+ "PEB %d, cancel", vol_id, lnum, from,
+ vol->eba_tbl[lnum]);
+ err = 1;
+ goto out_unlock_leb;
+ }
+
+ /*
+ * OK, now the LEB is locked and we can safely start moving iy. Since
+ * this function utilizes thie @ubi->peb1_buf buffer which is shared
+ * with some other functions, so lock the buffer by taking the
+ * @ubi->buf_mutex.
+ */
+ mutex_lock(&ubi->buf_mutex);
+ dbg_eba("read %d bytes of data", aldata_size);
+ err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size);
+ if (err && err != UBI_IO_BITFLIPS) {
+ ubi_warn("error %d while reading data from PEB %d",
+ err, from);
+ goto out_unlock_buf;
+ }
+
+ /*
+ * Now we have got to calculate how much data we have to to copy. In
+ * case of a static volume it is fairly easy - the VID header contains
+ * the data size. In case of a dynamic volume it is more difficult - we
+ * have to read the contents, cut 0xFF bytes from the end and copy only
+ * the first part. We must do this to avoid writing 0xFF bytes as it
+ * may have some side-effects. And not only this. It is important not
+ * to include those 0xFFs to CRC because later the they may be filled
+ * by data.
+ */
+ if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
+ aldata_size = data_size =
+ ubi_calc_data_len(ubi, ubi->peb_buf1, data_size);
+
+ cond_resched();
+ crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size);
+ cond_resched();
+
+ /*
+ * It may turn out to me that the whole @from physical eraseblock
+ * contains only 0xFF bytes. Then we have to only write the VID header
+ * and do not write any data. This also means we should not set
+ * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
+ */
+ if (data_size > 0) {
+ vid_hdr->copy_flag = 1;
+ vid_hdr->data_size = cpu_to_be32(data_size);
+ vid_hdr->data_crc = cpu_to_be32(crc);
+ }
+ vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+
+ err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
+ if (err)
+ goto out_unlock_buf;
+
+ cond_resched();
+
+ /* Read the VID header back and check if it was written correctly */
+ err = ubi_io_read_vid_hdr(ubi, to, vid_hdr, 1);
+ if (err) {
+ if (err != UBI_IO_BITFLIPS)
+ ubi_warn("cannot read VID header back from PEB %d", to);
+ else
+ err = 1;
+ goto out_unlock_buf;
+ }
+
+ if (data_size > 0) {
+ err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
+ if (err)
+ goto out_unlock_buf;
+
+ cond_resched();
+
+ /*
+ * We've written the data and are going to read it back to make
+ * sure it was written correctly.
+ */
+
+ err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size);
+ if (err) {
+ if (err != UBI_IO_BITFLIPS)
+ ubi_warn("cannot read data back from PEB %d",
+ to);
+ else
+ err = 1;
+ goto out_unlock_buf;
+ }
+
+ cond_resched();
+
+ if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
+ ubi_warn("read data back from PEB %d - it is different",
+ to);
+ goto out_unlock_buf;
+ }
+ }
+
+ ubi_assert(vol->eba_tbl[lnum] == from);
+ vol->eba_tbl[lnum] = to;
+
+out_unlock_buf:
+ mutex_unlock(&ubi->buf_mutex);
+out_unlock_leb:
+ leb_write_unlock(ubi, vol_id, lnum);
+ return err;
+}
+
+/**
+ * ubi_eba_init_scan - initialize the EBA unit using scanning information.
+ * @ubi: UBI device description object
+ * @si: scanning information
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
+{
+ int i, j, err, num_volumes;
+ struct ubi_scan_volume *sv;
+ struct ubi_volume *vol;
+ struct ubi_scan_leb *seb;
+ struct rb_node *rb;
+
+ dbg_eba("initialize EBA unit");
+
+ spin_lock_init(&ubi->ltree_lock);
+ mutex_init(&ubi->alc_mutex);
+ ubi->ltree = RB_ROOT;
+
+ ubi->global_sqnum = si->max_sqnum + 1;
+ num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
+
+ for (i = 0; i < num_volumes; i++) {
+ vol = ubi->volumes[i];
+ if (!vol)
+ continue;
+
+ cond_resched();
+
+ vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int),
+ GFP_KERNEL);
+ if (!vol->eba_tbl) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ for (j = 0; j < vol->reserved_pebs; j++)
+ vol->eba_tbl[j] = UBI_LEB_UNMAPPED;
+
+ sv = ubi_scan_find_sv(si, idx2vol_id(ubi, i));
+ if (!sv)
+ continue;
+
+ ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
+ if (seb->lnum >= vol->reserved_pebs)
+ /*
+ * This may happen in case of an unclean reboot
+ * during re-size.
+ */
+ ubi_scan_move_to_list(sv, seb, &si->erase);
+ vol->eba_tbl[seb->lnum] = seb->pnum;
+ }
+ }
+
+ if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
+ ubi_err("no enough physical eraseblocks (%d, need %d)",
+ ubi->avail_pebs, EBA_RESERVED_PEBS);
+ err = -ENOSPC;
+ goto out_free;
+ }
+ ubi->avail_pebs -= EBA_RESERVED_PEBS;
+ ubi->rsvd_pebs += EBA_RESERVED_PEBS;
+
+ if (ubi->bad_allowed) {
+ ubi_calculate_reserved(ubi);
+
+ if (ubi->avail_pebs < ubi->beb_rsvd_level) {
+ /* No enough free physical eraseblocks */
+ ubi->beb_rsvd_pebs = ubi->avail_pebs;
+ ubi_warn("cannot reserve enough PEBs for bad PEB "
+ "handling, reserved %d, need %d",
+ ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
+ } else
+ ubi->beb_rsvd_pebs = ubi->beb_rsvd_level;
+
+ ubi->avail_pebs -= ubi->beb_rsvd_pebs;
+ ubi->rsvd_pebs += ubi->beb_rsvd_pebs;
+ }
+
+ dbg_eba("EBA unit is initialized");
+ return 0;
+
+out_free:
+ for (i = 0; i < num_volumes; i++) {
+ if (!ubi->volumes[i])
+ continue;
+ kfree(ubi->volumes[i]->eba_tbl);
+ }
+ return err;
+}
+
+/**
+ * ubi_eba_close - close EBA unit.
+ * @ubi: UBI device description object
+ */
+void ubi_eba_close(const struct ubi_device *ubi)
+{
+ int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
+
+ dbg_eba("close EBA unit");
+
+ for (i = 0; i < num_volumes; i++) {
+ if (!ubi->volumes[i])
+ continue;
+ kfree(ubi->volumes[i]->eba_tbl);
+ }
+}
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
new file mode 100644
index 0000000..623ab76
--- /dev/null
+++ b/drivers/mtd/ubi/io.c
@@ -0,0 +1,1273 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ * Copyright (c) Nokia Corporation, 2006, 2007
+ *
+ * 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 input/output unit.
+ *
+ * This unit provides a uniform way to work with all kinds of the underlying
+ * MTD devices. It also implements handy functions for reading and writing UBI
+ * headers.
+ *
+ * We are trying to have a paranoid mindset and not to trust to what we read
+ * from the flash media in order to be more secure and robust. So this unit
+ * validates every single header it reads from the flash media.
+ *
+ * Some words about how the eraseblock headers are stored.
+ *
+ * The erase counter header is always stored at offset zero. By default, the
+ * VID header is stored after the EC header at the closest aligned offset
+ * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
+ * header at the closest aligned offset. But this default layout may be
+ * changed. For example, for different reasons (e.g., optimization) UBI may be
+ * asked to put the VID header at further offset, and even at an unaligned
+ * offset. Of course, if the offset of the VID header is unaligned, UBI adds
+ * proper padding in front of it. Data offset may also be changed but it has to
+ * be aligned.
+ *
+ * About minimal I/O units. In general, UBI assumes flash device model where
+ * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
+ * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
+ * @ubi->mtd->writesize field. But as an exception, UBI admits of using another
+ * (smaller) minimal I/O unit size for EC and VID headers to make it possible
+ * to do different optimizations.
+ *
+ * This is extremely useful in case of NAND flashes which admit of several
+ * write operations to one NAND page. In this case UBI can fit EC and VID
+ * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
+ * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
+ * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
+ * users.
+ *
+ * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
+ * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
+ * headers.
+ *
+ * Q: why not just to treat sub-page as a minimal I/O unit of this flash
+ * device, e.g., make @ubi->min_io_size = 512 in the example above?
+ *
+ * A: because when writing a sub-page, MTD still writes a full 2K page but the
+ * bytes which are no relevant to the sub-page are 0xFF. So, basically, writing
+ * 4x512 sub-pages is 4 times slower then writing one 2KiB NAND page. Thus, we
+ * prefer to use sub-pages only for EV and VID headers.
+ *
+ * As it was noted above, the VID header may start at a non-aligned offset.
+ * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
+ * the VID header may reside at offset 1984 which is the last 64 bytes of the
+ * last sub-page (EC header is always at offset zero). This causes some
+ * difficulties when reading and writing VID headers.
+ *
+ * Suppose we have a 64-byte buffer and we read a VID header at it. We change
+ * the data and want to write this VID header out. As we can only write in
+ * 512-byte chunks, we have to allocate one more buffer and copy our VID header
+ * to offset 448 of this buffer.
+ *
+ * The I/O unit does the following trick in order to avoid this extra copy.
+ * It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID header
+ * and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. When the
+ * VID header is being written out, it shifts the VID header pointer back and
+ * writes the whole sub-page.
+ */
+
+#ifdef UBI_LINUX
+#include <linux/crc32.h>
+#include <linux/err.h>
+#endif
+
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum);
+static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
+static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
+ const struct ubi_ec_hdr *ec_hdr);
+static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
+static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
+ const struct ubi_vid_hdr *vid_hdr);
+static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
+ int len);
+#else
+#define paranoid_check_not_bad(ubi, pnum) 0
+#define paranoid_check_peb_ec_hdr(ubi, pnum) 0
+#define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0
+#define paranoid_check_peb_vid_hdr(ubi, pnum) 0
+#define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0
+#define paranoid_check_all_ff(ubi, pnum, offset, len) 0
+#endif
+
+/**
+ * ubi_io_read - read data from a physical eraseblock.
+ * @ubi: UBI device description object
+ * @buf: buffer where to store the read data
+ * @pnum: physical eraseblock number to read from
+ * @offset: offset within the physical eraseblock from where to read
+ * @len: how many bytes to read
+ *
+ * This function reads data from offset @offset of physical eraseblock @pnum
+ * and stores the read data in the @buf buffer. The following return codes are
+ * possible:
+ *
+ * o %0 if all the requested data were successfully read;
+ * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
+ * correctable bit-flips were detected; this is harmless but may indicate
+ * that this eraseblock may become bad soon (but do not have to);
+ * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
+ * example it can be an ECC error in case of NAND; this most probably means
+ * that the data is corrupted;
+ * o %-EIO if some I/O error occurred;
+ * o other negative error codes in case of other errors.
+ */
+int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
+ int len)
+{
+ int err, retries = 0;
+ size_t read;
+ loff_t addr;
+
+ dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
+
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+ ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
+ ubi_assert(len > 0);
+
+ err = paranoid_check_not_bad(ubi, pnum);
+ if (err)
+ return err > 0 ? -EINVAL : err;
+
+ addr = (loff_t)pnum * ubi->peb_size + offset;
+retry:
+ err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
+ if (err) {
+ if (err == -EUCLEAN) {
+ /*
+ * -EUCLEAN is reported if there was a bit-flip which
+ * was corrected, so this is harmless.
+ */
+ ubi_msg("fixable bit-flip detected at PEB %d", pnum);
+ ubi_assert(len == read);
+ return UBI_IO_BITFLIPS;
+ }
+
+ if (read != len && retries++ < UBI_IO_RETRIES) {
+ dbg_io("error %d while reading %d bytes from PEB %d:%d, "
+ "read only %zd bytes, retry",
+ err, len, pnum, offset, read);
+ yield();
+ goto retry;
+ }
+
+ ubi_err("error %d while reading %d bytes from PEB %d:%d, "
+ "read %zd bytes", err, len, pnum, offset, read);
+ ubi_dbg_dump_stack();
+
+ /*
+ * The driver should never return -EBADMSG if it failed to read
+ * all the requested data. But some buggy drivers might do
+ * this, so we change it to -EIO.
+ */
+ if (read != len && err == -EBADMSG) {
+ ubi_assert(0);
+ err = -EIO;
+ }
+ } else {
+ ubi_assert(len == read);
+
+ if (ubi_dbg_is_bitflip()) {
+ dbg_msg("bit-flip (emulated)");
+ err = UBI_IO_BITFLIPS;
+ }
+ }
+
+ return err;
+}
+
+/**
+ * ubi_io_write - write data to a physical eraseblock.
+ * @ubi: UBI device description object
+ * @buf: buffer with the data to write
+ * @pnum: physical eraseblock number to write to
+ * @offset: offset within the physical eraseblock where to write
+ * @len: how many bytes to write
+ *
+ * This function writes @len bytes of data from buffer @buf to offset @offset
+ * of physical eraseblock @pnum. If all the data were successfully written,
+ * zero is returned. If an error occurred, this function returns a negative
+ * error code. If %-EIO is returned, the physical eraseblock most probably went
+ * bad.
+ *
+ * Note, in case of an error, it is possible that something was still written
+ * to the flash media, but may be some garbage.
+ */
+int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
+ int len)
+{
+ int err;
+ size_t written;
+ loff_t addr;
+
+ dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
+
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+ ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
+ ubi_assert(offset % ubi->hdrs_min_io_size == 0);
+ ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
+
+ if (ubi->ro_mode) {
+ ubi_err("read-only mode");
+ return -EROFS;
+ }
+
+ /* The below has to be compiled out if paranoid checks are disabled */
+
+ err = paranoid_check_not_bad(ubi, pnum);
+ if (err)
+ return err > 0 ? -EINVAL : err;
+
+ /* The area we are writing to has to contain all 0xFF bytes */
+ err = paranoid_check_all_ff(ubi, pnum, offset, len);
+ if (err)
+ return err > 0 ? -EINVAL : err;
+
+ if (offset >= ubi->leb_start) {
+ /*
+ * We write to the data area of the physical eraseblock. Make
+ * sure it has valid EC and VID headers.
+ */
+ err = paranoid_check_peb_ec_hdr(ubi, pnum);
+ if (err)
+ return err > 0 ? -EINVAL : err;
+ err = paranoid_check_peb_vid_hdr(ubi, pnum);
+ if (err)
+ return err > 0 ? -EINVAL : err;
+ }
+
+ if (ubi_dbg_is_write_failure()) {
+ dbg_err("cannot write %d bytes to PEB %d:%d "
+ "(emulated)", len, pnum, offset);
+ ubi_dbg_dump_stack();
+ return -EIO;
+ }
+
+ addr = (loff_t)pnum * ubi->peb_size + offset;
+ err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf);
+ if (err) {
+ ubi_err("error %d while writing %d bytes to PEB %d:%d, written"
+ " %zd bytes", err, len, pnum, offset, written);
+ ubi_dbg_dump_stack();
+ } else
+ ubi_assert(written == len);
+
+ return err;
+}
+
+/**
+ * erase_callback - MTD erasure call-back.
+ * @ei: MTD erase information object.
+ *
+ * Note, even though MTD erase interface is asynchronous, all the current
+ * implementations are synchronous anyway.
+ */
+static void erase_callback(struct erase_info *ei)
+{
+ wake_up_interruptible((wait_queue_head_t *)ei->priv);
+}
+
+/**
+ * do_sync_erase - synchronously erase a physical eraseblock.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to erase
+ *
+ * This function synchronously erases physical eraseblock @pnum and returns
+ * zero in case of success and a negative error code in case of failure. If
+ * %-EIO is returned, the physical eraseblock most probably went bad.
+ */
+static int do_sync_erase(struct ubi_device *ubi, int pnum)
+{
+ int err, retries = 0;
+ struct erase_info ei;
+ wait_queue_head_t wq;
+
+ dbg_io("erase PEB %d", pnum);
+
+retry:
+ init_waitqueue_head(&wq);
+ memset(&ei, 0, sizeof(struct erase_info));
+
+ ei.mtd = ubi->mtd;
+ ei.addr = (loff_t)pnum * ubi->peb_size;
+ ei.len = ubi->peb_size;
+ ei.callback = erase_callback;
+ ei.priv = (unsigned long)&wq;
+
+ err = ubi->mtd->erase(ubi->mtd, &ei);
+ if (err) {
+ if (retries++ < UBI_IO_RETRIES) {
+ dbg_io("error %d while erasing PEB %d, retry",
+ err, pnum);
+ yield();
+ goto retry;
+ }
+ ubi_err("cannot erase PEB %d, error %d", pnum, err);
+ ubi_dbg_dump_stack();
+ return err;
+ }
+
+ err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
+ ei.state == MTD_ERASE_FAILED);
+ if (err) {
+ ubi_err("interrupted PEB %d erasure", pnum);
+ return -EINTR;
+ }
+
+ if (ei.state == MTD_ERASE_FAILED) {
+ if (retries++ < UBI_IO_RETRIES) {
+ dbg_io("error while erasing PEB %d, retry", pnum);
+ yield();
+ goto retry;
+ }
+ ubi_err("cannot erase PEB %d", pnum);
+ ubi_dbg_dump_stack();
+ return -EIO;
+ }
+
+ err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size);
+ if (err)
+ return err > 0 ? -EINVAL : err;
+
+ if (ubi_dbg_is_erase_failure() && !err) {
+ dbg_err("cannot erase PEB %d (emulated)", pnum);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/**
+ * check_pattern - check if buffer contains only a certain byte pattern.
+ * @buf: buffer to check
+ * @patt: the pattern to check
+ * @size: buffer size in bytes
+ *
+ * This function returns %1 in there are only @patt bytes in @buf, and %0 if
+ * something else was also found.
+ */
+static int check_pattern(const void *buf, uint8_t patt, int size)
+{
+ int i;
+
+ for (i = 0; i < size; i++)
+ if (((const uint8_t *)buf)[i] != patt)
+ return 0;
+ return 1;
+}
+
+/* Patterns to write to a physical eraseblock when torturing it */
+static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
+
+/**
+ * torture_peb - test a supposedly bad physical eraseblock.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to test
+ *
+ * This function returns %-EIO if the physical eraseblock did not pass the
+ * test, a positive number of erase operations done if the test was
+ * successfully passed, and other negative error codes in case of other errors.
+ */
+static int torture_peb(struct ubi_device *ubi, int pnum)
+{
+ int err, i, patt_count;
+
+ patt_count = ARRAY_SIZE(patterns);
+ ubi_assert(patt_count > 0);
+
+ mutex_lock(&ubi->buf_mutex);
+ for (i = 0; i < patt_count; i++) {
+ err = do_sync_erase(ubi, pnum);
+ if (err)
+ goto out;
+
+ /* Make sure the PEB contains only 0xFF bytes */
+ err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
+ if (err)
+ goto out;
+
+ err = check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
+ if (err == 0) {
+ ubi_err("erased PEB %d, but a non-0xFF byte found",
+ pnum);
+ err = -EIO;
+ goto out;
+ }
+
+ /* Write a pattern and check it */
+ memset(ubi->peb_buf1, patterns[i], ubi->peb_size);
+ err = ubi_io_write(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
+ if (err)
+ goto out;
+
+ memset(ubi->peb_buf1, ~patterns[i], ubi->peb_size);
+ err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
+ if (err)
+ goto out;
+
+ err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size);
+ if (err == 0) {
+ ubi_err("pattern %x checking failed for PEB %d",
+ patterns[i], pnum);
+ err = -EIO;
+ goto out;
+ }
+ }
+
+ err = patt_count;
+
+out:
+ mutex_unlock(&ubi->buf_mutex);
+ if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
+ /*
+ * If a bit-flip or data integrity error was detected, the test
+ * has not passed because it happened on a freshly erased
+ * physical eraseblock which means something is wrong with it.
+ */
+ ubi_err("read problems on freshly erased PEB %d, must be bad",
+ pnum);
+ err = -EIO;
+ }
+ return err;
+}
+
+/**
+ * ubi_io_sync_erase - synchronously erase a physical eraseblock.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number to erase
+ * @torture: if this physical eraseblock has to be tortured
+ *
+ * This function synchronously erases physical eraseblock @pnum. If @torture
+ * flag is not zero, the physical eraseblock is checked by means of writing
+ * different patterns to it and reading them back. If the torturing is enabled,
+ * the physical eraseblock is erased more then once.
+ *
+ * This function returns the number of erasures made in case of success, %-EIO
+ * if the erasure failed or the torturing test failed, and other negative error
+ * codes in case of other errors. Note, %-EIO means that the physical
+ * eraseblock is bad.
+ */
+int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
+{
+ int err, ret = 0;
+
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+ err = paranoid_check_not_bad(ubi, pnum);
+ if (err != 0)
+ return err > 0 ? -EINVAL : err;
+
+ if (ubi->ro_mode) {
+ ubi_err("read-only mode");
+ return -EROFS;
+ }
+
+ if (torture) {
+ ret = torture_peb(ubi, pnum);
+ if (ret < 0)
+ return ret;
+ }
+
+ err = do_sync_erase(ubi, pnum);
+ if (err)
+ return err;
+
+ return ret + 1;
+}
+
+/**
+ * ubi_io_is_bad - check if a physical eraseblock is bad.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ *
+ * This function returns a positive number if the physical eraseblock is bad,
+ * zero if not, and a negative error code if an error occurred.
+ */
+int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
+{
+ struct mtd_info *mtd = ubi->mtd;
+
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+ if (ubi->bad_allowed) {
+ int ret;
+
+ ret = mtd->block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
+ if (ret < 0)
+ ubi_err("error %d while checking if PEB %d is bad",
+ ret, pnum);
+ else if (ret)
+ dbg_io("PEB %d is bad", pnum);
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * ubi_io_mark_bad - mark a physical eraseblock as bad.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to mark
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
+{
+ int err;
+ struct mtd_info *mtd = ubi->mtd;
+
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+ if (ubi->ro_mode) {
+ ubi_err("read-only mode");
+ return -EROFS;
+ }
+
+ if (!ubi->bad_allowed)
+ return 0;
+
+ err = mtd->block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
+ if (err)
+ ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
+ return err;
+}
+
+/**
+ * validate_ec_hdr - validate an erase counter header.
+ * @ubi: UBI device description object
+ * @ec_hdr: the erase counter header to check
+ *
+ * This function returns zero if the erase counter header is OK, and %1 if
+ * not.
+ */
+static int validate_ec_hdr(const struct ubi_device *ubi,
+ const struct ubi_ec_hdr *ec_hdr)
+{
+ long long ec;
+ int vid_hdr_offset, leb_start;
+
+ ec = be64_to_cpu(ec_hdr->ec);
+ vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
+ leb_start = be32_to_cpu(ec_hdr->data_offset);
+
+ if (ec_hdr->version != UBI_VERSION) {
+ ubi_err("node with incompatible UBI version found: "
+ "this UBI version is %d, image version is %d",
+ UBI_VERSION, (int)ec_hdr->version);
+ goto bad;
+ }
+
+ if (vid_hdr_offset != ubi->vid_hdr_offset) {
+ ubi_err("bad VID header offset %d, expected %d",
+ vid_hdr_offset, ubi->vid_hdr_offset);
+ goto bad;
+ }
+
+ if (leb_start != ubi->leb_start) {
+ ubi_err("bad data offset %d, expected %d",
+ leb_start, ubi->leb_start);
+ goto bad;
+ }
+
+ if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
+ ubi_err("bad erase counter %lld", ec);
+ goto bad;
+ }
+
+ return 0;
+
+bad:
+ ubi_err("bad EC header");
+ ubi_dbg_dump_ec_hdr(ec_hdr);
+ ubi_dbg_dump_stack();
+ return 1;
+}
+
+/**
+ * ubi_io_read_ec_hdr - read and check an erase counter header.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock to read from
+ * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
+ * header
+ * @verbose: be verbose if the header is corrupted or was not found
+ *
+ * This function reads erase counter header from physical eraseblock @pnum and
+ * stores it in @ec_hdr. This function also checks CRC checksum of the read
+ * erase counter header. The following codes may be returned:
+ *
+ * o %0 if the CRC checksum is correct and the header was successfully read;
+ * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
+ * and corrected by the flash driver; this is harmless but may indicate that
+ * this eraseblock may become bad soon (but may be not);
+ * o %UBI_IO_BAD_EC_HDR if the erase counter header is corrupted (a CRC error);
+ * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
+ * o a negative error code in case of failure.
+ */
+int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
+ struct ubi_ec_hdr *ec_hdr, int verbose)
+{
+ int err, read_err = 0;
+ uint32_t crc, magic, hdr_crc;
+
+ dbg_io("read EC header from PEB %d", pnum);
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+ if (UBI_IO_DEBUG)
+ verbose = 1;
+
+ err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
+ if (err) {
+ if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
+ return err;
+
+ /*
+ * We read all the data, but either a correctable bit-flip
+ * occurred, or MTD reported about some data integrity error,
+ * like an ECC error in case of NAND. The former is harmless,
+ * the later may mean that the read data is corrupted. But we
+ * have a CRC check-sum and we will detect this. If the EC
+ * header is still OK, we just report this as there was a
+ * bit-flip.
+ */
+ read_err = err;
+ }
+
+ magic = be32_to_cpu(ec_hdr->magic);
+ if (magic != UBI_EC_HDR_MAGIC) {
+ /*
+ * The magic field is wrong. Let's check if we have read all
+ * 0xFF. If yes, this physical eraseblock is assumed to be
+ * empty.
+ *
+ * But if there was a read error, we do not test it for all
+ * 0xFFs. Even if it does contain all 0xFFs, this error
+ * indicates that something is still wrong with this physical
+ * eraseblock and we anyway cannot treat it as empty.
+ */
+ if (read_err != -EBADMSG &&
+ check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
+ /* The physical eraseblock is supposedly empty */
+
+ /*
+ * The below is just a paranoid check, it has to be
+ * compiled out if paranoid checks are disabled.
+ */
+ err = paranoid_check_all_ff(ubi, pnum, 0,
+ ubi->peb_size);
+ if (err)
+ return err > 0 ? UBI_IO_BAD_EC_HDR : err;
+
+ if (verbose)
+ ubi_warn("no EC header found at PEB %d, "
+ "only 0xFF bytes", pnum);
+ return UBI_IO_PEB_EMPTY;
+ }
+
+ /*
+ * This is not a valid erase counter header, and these are not
+ * 0xFF bytes. Report that the header is corrupted.
+ */
+ if (verbose) {
+ ubi_warn("bad magic number at PEB %d: %08x instead of "
+ "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
+ ubi_dbg_dump_ec_hdr(ec_hdr);
+ }
+ return UBI_IO_BAD_EC_HDR;
+ }
+
+ crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
+ hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
+
+ if (hdr_crc != crc) {
+ if (verbose) {
+ ubi_warn("bad EC header CRC at PEB %d, calculated %#08x,"
+ " read %#08x", pnum, crc, hdr_crc);
+ ubi_dbg_dump_ec_hdr(ec_hdr);
+ }
+ return UBI_IO_BAD_EC_HDR;
+ }
+
+ /* And of course validate what has just been read from the media */
+ err = validate_ec_hdr(ubi, ec_hdr);
+ if (err) {
+ ubi_err("validation failed for PEB %d", pnum);
+ return -EINVAL;
+ }
+
+ return read_err ? UBI_IO_BITFLIPS : 0;
+}
+
+/**
+ * ubi_io_write_ec_hdr - write an erase counter header.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock to write to
+ * @ec_hdr: the erase counter header to write
+ *
+ * This function writes erase counter header described by @ec_hdr to physical
+ * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
+ * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
+ * field.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure. If %-EIO is returned, the physical eraseblock most probably
+ * went bad.
+ */
+int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
+ struct ubi_ec_hdr *ec_hdr)
+{
+ int err;
+ uint32_t crc;
+
+ dbg_io("write EC header to PEB %d", pnum);
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+ ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
+ ec_hdr->version = UBI_VERSION;
+ ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
+ ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
+ crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
+ ec_hdr->hdr_crc = cpu_to_be32(crc);
+
+ err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
+ if (err)
+ return -EINVAL;
+
+ err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
+ return err;
+}
+
+/**
+ * validate_vid_hdr - validate a volume identifier header.
+ * @ubi: UBI device description object
+ * @vid_hdr: the volume identifier header to check
+ *
+ * This function checks that data stored in the volume identifier header
+ * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
+ */
+static int validate_vid_hdr(const struct ubi_device *ubi,
+ const struct ubi_vid_hdr *vid_hdr)
+{
+ int vol_type = vid_hdr->vol_type;
+ int copy_flag = vid_hdr->copy_flag;
+ int vol_id = be32_to_cpu(vid_hdr->vol_id);
+ int lnum = be32_to_cpu(vid_hdr->lnum);
+ int compat = vid_hdr->compat;
+ int data_size = be32_to_cpu(vid_hdr->data_size);
+ int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
+ int data_pad = be32_to_cpu(vid_hdr->data_pad);
+ int data_crc = be32_to_cpu(vid_hdr->data_crc);
+ int usable_leb_size = ubi->leb_size - data_pad;
+
+ if (copy_flag != 0 && copy_flag != 1) {
+ dbg_err("bad copy_flag");
+ goto bad;
+ }
+
+ if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
+ data_pad < 0) {
+ dbg_err("negative values");
+ goto bad;
+ }
+
+ if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
+ dbg_err("bad vol_id");
+ goto bad;
+ }
+
+ if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
+ dbg_err("bad compat");
+ goto bad;
+ }
+
+ if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
+ compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
+ compat != UBI_COMPAT_REJECT) {
+ dbg_err("bad compat");
+ goto bad;
+ }
+
+ if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
+ dbg_err("bad vol_type");
+ goto bad;
+ }
+
+ if (data_pad >= ubi->leb_size / 2) {
+ dbg_err("bad data_pad");
+ goto bad;
+ }
+
+ if (vol_type == UBI_VID_STATIC) {
+ /*
+ * Although from high-level point of view static volumes may
+ * contain zero bytes of data, but no VID headers can contain
+ * zero at these fields, because they empty volumes do not have
+ * mapped logical eraseblocks.
+ */
+ if (used_ebs == 0) {
+ dbg_err("zero used_ebs");
+ goto bad;
+ }
+ if (data_size == 0) {
+ dbg_err("zero data_size");
+ goto bad;
+ }
+ if (lnum < used_ebs - 1) {
+ if (data_size != usable_leb_size) {
+ dbg_err("bad data_size");
+ goto bad;
+ }
+ } else if (lnum == used_ebs - 1) {
+ if (data_size == 0) {
+ dbg_err("bad data_size at last LEB");
+ goto bad;
+ }
+ } else {
+ dbg_err("too high lnum");
+ goto bad;
+ }
+ } else {
+ if (copy_flag == 0) {
+ if (data_crc != 0) {
+ dbg_err("non-zero data CRC");
+ goto bad;
+ }
+ if (data_size != 0) {
+ dbg_err("non-zero data_size");
+ goto bad;
+ }
+ } else {
+ if (data_size == 0) {
+ dbg_err("zero data_size of copy");
+ goto bad;
+ }
+ }
+ if (used_ebs != 0) {
+ dbg_err("bad used_ebs");
+ goto bad;
+ }
+ }
+
+ return 0;
+
+bad:
+ ubi_err("bad VID header");
+ ubi_dbg_dump_vid_hdr(vid_hdr);
+ ubi_dbg_dump_stack();
+ return 1;
+}
+
+/**
+ * ubi_io_read_vid_hdr - read and check a volume identifier header.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number to read from
+ * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
+ * identifier header
+ * @verbose: be verbose if the header is corrupted or wasn't found
+ *
+ * This function reads the volume identifier header from physical eraseblock
+ * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
+ * volume identifier header. The following codes may be returned:
+ *
+ * o %0 if the CRC checksum is correct and the header was successfully read;
+ * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
+ * and corrected by the flash driver; this is harmless but may indicate that
+ * this eraseblock may become bad soon;
+ * o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC
+ * error detected);
+ * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
+ * header there);
+ * o a negative error code in case of failure.
+ */
+int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
+ struct ubi_vid_hdr *vid_hdr, int verbose)
+{
+ int err, read_err = 0;
+ uint32_t crc, magic, hdr_crc;
+ void *p;
+
+ dbg_io("read VID header from PEB %d", pnum);
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+ if (UBI_IO_DEBUG)
+ verbose = 1;
+
+ p = (char *)vid_hdr - ubi->vid_hdr_shift;
+ err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
+ ubi->vid_hdr_alsize);
+ if (err) {
+ if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
+ return err;
+
+ /*
+ * We read all the data, but either a correctable bit-flip
+ * occurred, or MTD reported about some data integrity error,
+ * like an ECC error in case of NAND. The former is harmless,
+ * the later may mean the read data is corrupted. But we have a
+ * CRC check-sum and we will identify this. If the VID header is
+ * still OK, we just report this as there was a bit-flip.
+ */
+ read_err = err;
+ }
+
+ magic = be32_to_cpu(vid_hdr->magic);
+ if (magic != UBI_VID_HDR_MAGIC) {
+ /*
+ * If we have read all 0xFF bytes, the VID header probably does
+ * not exist and the physical eraseblock is assumed to be free.
+ *
+ * But if there was a read error, we do not test the data for
+ * 0xFFs. Even if it does contain all 0xFFs, this error
+ * indicates that something is still wrong with this physical
+ * eraseblock and it cannot be regarded as free.
+ */
+ if (read_err != -EBADMSG &&
+ check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
+ /* The physical eraseblock is supposedly free */
+
+ /*
+ * The below is just a paranoid check, it has to be
+ * compiled out if paranoid checks are disabled.
+ */
+ err = paranoid_check_all_ff(ubi, pnum, ubi->leb_start,
+ ubi->leb_size);
+ if (err)
+ return err > 0 ? UBI_IO_BAD_VID_HDR : err;
+
+ if (verbose)
+ ubi_warn("no VID header found at PEB %d, "
+ "only 0xFF bytes", pnum);
+ return UBI_IO_PEB_FREE;
+ }
+
+ /*
+ * This is not a valid VID header, and these are not 0xFF
+ * bytes. Report that the header is corrupted.
+ */
+ if (verbose) {
+ ubi_warn("bad magic number at PEB %d: %08x instead of "
+ "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
+ ubi_dbg_dump_vid_hdr(vid_hdr);
+ }
+ return UBI_IO_BAD_VID_HDR;
+ }
+
+ crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
+ hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
+
+ if (hdr_crc != crc) {
+ if (verbose) {
+ ubi_warn("bad CRC at PEB %d, calculated %#08x, "
+ "read %#08x", pnum, crc, hdr_crc);
+ ubi_dbg_dump_vid_hdr(vid_hdr);
+ }
+ return UBI_IO_BAD_VID_HDR;
+ }
+
+ /* Validate the VID header that we have just read */
+ err = validate_vid_hdr(ubi, vid_hdr);
+ if (err) {
+ ubi_err("validation failed for PEB %d", pnum);
+ return -EINVAL;
+ }
+
+ return read_err ? UBI_IO_BITFLIPS : 0;
+}
+
+/**
+ * ubi_io_write_vid_hdr - write a volume identifier header.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to write to
+ * @vid_hdr: the volume identifier header to write
+ *
+ * This function writes the volume identifier header described by @vid_hdr to
+ * physical eraseblock @pnum. This function automatically fills the
+ * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
+ * header CRC checksum and stores it at vid_hdr->hdr_crc.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure. If %-EIO is returned, the physical eraseblock probably went
+ * bad.
+ */
+int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
+ struct ubi_vid_hdr *vid_hdr)
+{
+ int err;
+ uint32_t crc;
+ void *p;
+
+ dbg_io("write VID header to PEB %d", pnum);
+ ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+ err = paranoid_check_peb_ec_hdr(ubi, pnum);
+ if (err)
+ return err > 0 ? -EINVAL: err;
+
+ vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
+ vid_hdr->version = UBI_VERSION;
+ crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
+ vid_hdr->hdr_crc = cpu_to_be32(crc);
+
+ err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
+ if (err)
+ return -EINVAL;
+
+ p = (char *)vid_hdr - ubi->vid_hdr_shift;
+ err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
+ ubi->vid_hdr_alsize);
+ return err;
+}
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+
+/**
+ * paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number to check
+ *
+ * This function returns zero if the physical eraseblock is good, a positive
+ * number if it is bad and a negative error code if an error occurred.
+ */
+static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
+{
+ int err;
+
+ err = ubi_io_is_bad(ubi, pnum);
+ if (!err)
+ return err;
+
+ ubi_err("paranoid check failed for PEB %d", pnum);
+ ubi_dbg_dump_stack();
+ return err;
+}
+
+/**
+ * paranoid_check_ec_hdr - check if an erase counter header is all right.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number the erase counter header belongs to
+ * @ec_hdr: the erase counter header to check
+ *
+ * This function returns zero if the erase counter header contains valid
+ * values, and %1 if not.
+ */
+static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
+ const struct ubi_ec_hdr *ec_hdr)
+{
+ int err;
+ uint32_t magic;
+
+ magic = be32_to_cpu(ec_hdr->magic);
+ if (magic != UBI_EC_HDR_MAGIC) {
+ ubi_err("bad magic %#08x, must be %#08x",
+ magic, UBI_EC_HDR_MAGIC);
+ goto fail;
+ }
+
+ err = validate_ec_hdr(ubi, ec_hdr);
+ if (err) {
+ ubi_err("paranoid check failed for PEB %d", pnum);
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ ubi_dbg_dump_ec_hdr(ec_hdr);
+ ubi_dbg_dump_stack();
+ return 1;
+}
+
+/**
+ * paranoid_check_peb_ec_hdr - check that the erase counter header of a
+ * physical eraseblock is in-place and is all right.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ *
+ * This function returns zero if the erase counter header is all right, %1 if
+ * not, and a negative error code if an error occurred.
+ */
+static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
+{
+ int err;
+ uint32_t crc, hdr_crc;
+ struct ubi_ec_hdr *ec_hdr;
+
+ ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
+ if (!ec_hdr)
+ return -ENOMEM;
+
+ err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
+ if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
+ goto exit;
+
+ crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
+ hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
+ if (hdr_crc != crc) {
+ ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
+ ubi_err("paranoid check failed for PEB %d", pnum);
+ ubi_dbg_dump_ec_hdr(ec_hdr);
+ ubi_dbg_dump_stack();
+ err = 1;
+ goto exit;
+ }
+
+ err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
+
+exit:
+ kfree(ec_hdr);
+ return err;
+}
+
+/**
+ * paranoid_check_vid_hdr - check that a volume identifier header is all right.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number the volume identifier header belongs to
+ * @vid_hdr: the volume identifier header to check
+ *
+ * This function returns zero if the volume identifier header is all right, and
+ * %1 if not.
+ */
+static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
+ const struct ubi_vid_hdr *vid_hdr)
+{
+ int err;
+ uint32_t magic;
+
+ magic = be32_to_cpu(vid_hdr->magic);
+ if (magic != UBI_VID_HDR_MAGIC) {
+ ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
+ magic, pnum, UBI_VID_HDR_MAGIC);
+ goto fail;
+ }
+
+ err = validate_vid_hdr(ubi, vid_hdr);
+ if (err) {
+ ubi_err("paranoid check failed for PEB %d", pnum);
+ goto fail;
+ }
+
+ return err;
+
+fail:
+ ubi_err("paranoid check failed for PEB %d", pnum);
+ ubi_dbg_dump_vid_hdr(vid_hdr);
+ ubi_dbg_dump_stack();
+ return 1;
+
+}
+
+/**
+ * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
+ * physical eraseblock is in-place and is all right.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ *
+ * This function returns zero if the volume identifier header is all right,
+ * %1 if not, and a negative error code if an error occurred.
+ */
+static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
+{
+ int err;
+ uint32_t crc, hdr_crc;
+ struct ubi_vid_hdr *vid_hdr;
+ void *p;
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ if (!vid_hdr)
+ return -ENOMEM;
+
+ p = (char *)vid_hdr - ubi->vid_hdr_shift;
+ err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
+ ubi->vid_hdr_alsize);
+ if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
+ goto exit;
+
+ crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
+ hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
+ if (hdr_crc != crc) {
+ ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
+ "read %#08x", pnum, crc, hdr_crc);
+ ubi_err("paranoid check failed for PEB %d", pnum);
+ ubi_dbg_dump_vid_hdr(vid_hdr);
+ ubi_dbg_dump_stack();
+ err = 1;
+ goto exit;
+ }
+
+ err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
+
+exit:
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+}
+
+/**
+ * paranoid_check_all_ff - check that a region of flash is empty.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ * @offset: the starting offset within the physical eraseblock to check
+ * @len: the length of the region to check
+ *
+ * This function returns zero if only 0xFF bytes are present at offset
+ * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
+ * code if an error occurred.
+ */
+static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
+ int len)
+{
+ size_t read;
+ int err;
+ loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
+
+ mutex_lock(&ubi->dbg_buf_mutex);
+ err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf);
+ if (err && err != -EUCLEAN) {
+ ubi_err("error %d while reading %d bytes from PEB %d:%d, "
+ "read %zd bytes", err, len, pnum, offset, read);
+ goto error;
+ }
+
+ err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
+ if (err == 0) {
+ ubi_err("flash region at PEB %d:%d, length %d does not "
+ "contain all 0xFF bytes", pnum, offset, len);
+ goto fail;
+ }
+ mutex_unlock(&ubi->dbg_buf_mutex);
+
+ return 0;
+
+fail:
+ ubi_err("paranoid check failed for PEB %d", pnum);
+ dbg_msg("hex dump of the %d-%d region", offset, offset + len);
+ print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+ ubi->dbg_peb_buf, len, 1);
+ err = 1;
+error:
+ ubi_dbg_dump_stack();
+ mutex_unlock(&ubi->dbg_buf_mutex);
+ return err;
+}
+
+#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
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