--- /dev/null
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * 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);
+
+ if (le_free)
+ 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 (mtd_is_eccerr(err)) {
+ 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);
+ }
+}
Code Review / kvmfornfv.git / blobdiff