[PATCH 10/22 take 3] UBI: EBA unit

Artem Bityutskiy
2007-03-14T15:21:55Z

diff -auNrp tmp-from/drivers/mtd/ubi/eba.c tmp-to/drivers/mtd/ubi/eba.c
--- tmp-from/drivers/mtd/ubi/eba.c 1970-01-01 02:00:00.000000000 +0200
+++ tmp-to/drivers/mtd/ubi/eba.c 2007-03-14 17:15:50.000000000 +0200
@@ -0,0 +1,1735 @@
+/*
+ * 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 B. Bityutskiy
+ */
+
+/*
+ * The UBI Eraseblock Association (EBA) unit.
+ *
+ * This unit maintains the Eraseblock Association Table (EBA table). The EBA
+ * table is a data structure which maps (volume ID, logical eraseblock number)
+ * pairs to physical eraseblock numbers.
+ *
+ * All the UBI input/output goes via the EBA unit. The only reservation is made
+ * for the initialization time when different units may directly do
+ * input/output from physical eraseblocks.
+ *
+ * Although in this implementation the EBA table is fully kept and managed in
+ * RAM, which assumes poor UBI 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 a lock tree. The lock tree is
+ * an RB-tree which refers all the currently locked logical eraseblocks. The
+ * lock tree elements are &struct ubi_eba_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.
+ */
+
+#include <linux/slab.h>
+#include <linux/crc32.h>
+#include <linux/err.h>
+#include "ubi.h"
+
+/**
+ * struct ubi_eba_tbl_rec - a record in the eraseblock association table.
+ *
+ * @pnum: physical eraseblock number
+ * @leb_ver: LEB version (obsolete)
+ *
+ * This structure represents a record in the eraseblock association table.
+ */
+struct ubi_eba_tbl_rec {
+ int pnum;
+ uint32_t leb_ver; /* FIXME: obsolete, to be removed */
+};
+
+/**
+ * struct ubi_eba_tbl_volume - a volume in the the eraseblock association
+ * table.
+ *
+ * @recs: an array of per-logical eraseblock records (for each logical
+ * eraseblock of this volume)
+ * @leb_count: how many logical eraseblock this volume has
+ */
+struct ubi_eba_tbl_volume {
+ struct ubi_eba_tbl_rec *recs;
+ int leb_count;
+};
+
+/**
+ * struct ubi_eba_ltree_entry - an entry in the lock tree.
+ *
+ * @rb: links RB-tree nodes
+ * @vol_id: volume ID of the locked logical eraseblock
+ * @lnum: locked logical eraseblock number
+ * @users: how many tasks are using this logical eraseblock or wait for it
+ * @mutex: a read/write mutex to implement read/write access serialization to
+ * the (@vol_id, @lnum) logical eraseblock
+ *
+ * When a logical eraseblock is being locked - corresponding &struct
+ * ubi_eba_ltree_entry object is inserted to the lock tree (@eba->ltree).
+ */
+struct ubi_eba_ltree_entry {
+ struct rb_node rb;
+ int vol_id;
+ int lnum;
+ int users;
+ struct rw_semaphore mutex;
+};
+
+/*
+ * The top-most bit in logical-to-physical eraseblock mappings is used to
+ * indicate that the logical eraseblock is not mapped.
+ */
+#define NOT_MAPPED 0x80000000
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID_EBA
+static int paranoid_check_leb(const struct ubi_info *ubi, int pnum, int vol_id,
+ int lnum, const struct ubi_vid_hdr *vid_hdr);
+static int paranoid_check_leb_locked(struct ubi_info *ubi, int vol_id,
+ int lnum);
+#else
+#define paranoid_check_leb(ubi, vol_id, pnum, lnum, vid_hdr) 0
+#define paranoid_check_leb_locked(ubi, vol_id, lnum)
+#endif
+
+/* Slab cache for lock-tree entries */
+static struct kmem_cache *eba_ltree_entry_slab;
+
+/**
+ * vol_id2idx - turn volume ID to the EBA table index.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID
+ */
+static inline int vol_id2idx(const struct ubi_info *ubi, int vol_id)
+{
+ if (vol_id >= UBI_INTERNAL_VOL_START)
+ return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl.vt_slots;
+ else
+ return vol_id;
+}
+
+/**
+ * idx2vol_id - turn an EBA table index to the volume ID.
+ *
+ * @ubi: the UBI device description object
+ * @idx: the EBA table index
+ */
+static inline int idx2vol_id(const struct ubi_info *ubi, int idx)
+{
+ if (idx >= ubi->vtbl.vt_slots)
+ return idx - ubi->vtbl.vt_slots + UBI_INTERNAL_VOL_START;
+ else
+ return idx;
+}
+
+/**
+ * leb_get_ver - get logical eraseblock version.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID
+ * @lnum: the logical eraseblock number
+ *
+ * The logical eraseblock has to be locked. Note, all this leb_ver stuff is
+ * obsolete and will be removed eventually. FIXME: to be removed together with
+ * leb_ver support.
+ */
+static inline int leb_get_ver(struct ubi_info *ubi, int vol_id, int lnum)
+{
+ int idx, leb_ver;
+
+ idx = vol_id2idx(ubi, vol_id);
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ ubi_assert(ubi->eba.eba_tbl[idx].recs);
+ leb_ver = ubi->eba.eba_tbl[idx].recs[lnum].leb_ver;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ return leb_ver;
+}
+
+/**
+ * next_sqnum - get next sequence number.
+ *
+ * @ubi: the 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_info *ubi)
+{
+ unsigned long long sqnum;
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ sqnum = ubi->eba.global_sq_cnt++;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ return sqnum;
+}
+
+/**
+ * leb_map - map a logical eraseblock to a physical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID
+ * @lnum: the logical eraseblock number
+ * @pnum: the physical eraseblock
+ *
+ * The logical eraseblock has to be locked.
+ */
+static inline void leb_map(struct ubi_info *ubi, int vol_id, int lnum, int pnum)
+{
+ int idx;
+
+ idx = vol_id2idx(ubi, vol_id);
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ ubi_assert(ubi->eba.eba_tbl[idx].recs);
+ ubi_assert(ubi->eba.eba_tbl[idx].recs[lnum].pnum < 0);
+ ubi->eba.eba_tbl[idx].recs[lnum].pnum = pnum;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+}
+
+/**
+ * leb_unmap - un-map a logical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID
+ * @lnum: the logical eraseblock number to unmap
+ *
+ * This function un-maps a logical eraseblock and increases its version. The
+ * logical eraseblock has to be locked.
+ */
+static inline void leb_unmap(struct ubi_info *ubi, int vol_id, int lnum)
+{
+ int idx;
+
+ idx = vol_id2idx(ubi, vol_id);
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ ubi_assert(ubi->eba.eba_tbl[idx].recs);
+ ubi_assert(ubi->eba.eba_tbl[idx].recs[lnum].pnum >= 0);
+ ubi->eba.eba_tbl[idx].recs[lnum].pnum |= NOT_MAPPED;
+ ubi->eba.eba_tbl[idx].recs[lnum].leb_ver += 1;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+}
+
+/**
+ * leb2peb - get physical eraseblock number by logical eraseblock number.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID
+ * @lnum: the logical eraseblock number
+ *
+ * If the logical eraseblock is mapped, this function returns a positive
+ * physical eraseblock number. If it is not mapped, this function returns
+ * a negative number.
+ */
+static inline int leb2peb(struct ubi_info *ubi, int vol_id, int lnum)
+{
+ int idx, pnum;
+
+ idx = vol_id2idx(ubi, vol_id);
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ ubi_assert(ubi->eba.eba_tbl[idx].recs);
+ pnum = ubi->eba.eba_tbl[idx].recs[lnum].pnum;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ return pnum;
+}
+
+/**
+ * ubi_eba_mkvol - create EBA mapping for a new volume.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: ID of the new volume
+ * @leb_count: how many eraseblocks are reserved for this volume
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_eba_mkvol(struct ubi_info *ubi, int vol_id, int reserved_pebs)
+{
+ int i, idx, sz;
+ struct ubi_eba_tbl_rec *new_ebs;
+ struct ubi_eba_tbl_volume *eba_tbl = ubi->eba.eba_tbl;
+
+ dbg_eba("create volume %d, size %d", vol_id, reserved_pebs);
+
+ ubi_assert(vol_id >= 0);
+ ubi_assert(reserved_pebs > 0);
+ ubi_assert(!ubi_is_ivol(vol_id));
+ ubi_assert(vol_id < ubi->vtbl.vt_slots);
+
+ if (ubi->io.ro_mode) {
+ dbg_err("read-only mode");
+ return -EROFS;
+ }
+
+ sz = reserved_pebs * sizeof(struct ubi_eba_tbl_rec);
+ new_ebs = kmalloc(sz, GFP_KERNEL);
+ if (!new_ebs)
+ return -ENOMEM;
+
+ for (i = 0; i < reserved_pebs; i++) {
+ new_ebs[i].pnum = NOT_MAPPED;
+ new_ebs[i].leb_ver = 0xFFFFFFF0;
+ }
+
+ idx = vol_id2idx(ubi, vol_id);
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ ubi_assert(!eba_tbl[idx].recs);
+ eba_tbl[idx].recs = new_ebs;
+ eba_tbl[idx].leb_count = reserved_pebs;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ return 0;
+}
+
+/**
+ * ubi_eba_rmvol - remove EBA mapping of a volume.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: ID of the volume to be removed
+ *
+ * This function removes a volume from the EBA table. It un-maps all the
+ * logical eraseblocks and the corresponding physical eraseblocks are scheduled
+ * for erasure. Returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_eba_rmvol(struct ubi_info *ubi, int vol_id)
+{
+ int err = 0, i, idx, to_put;
+ struct ubi_eba_tbl_rec *rm_ebs;
+ struct ubi_eba_tbl_volume *eba_tbl = ubi->eba.eba_tbl;
+
+ dbg_eba("remove volume %d", vol_id);
+
+ ubi_assert(vol_id >= 0);
+ ubi_assert(!ubi_is_ivol(vol_id));
+ ubi_assert(vol_id < ubi->vtbl.vt_slots);
+
+ if (ubi->io.ro_mode) {
+ dbg_err("read-only mode");
+ return -EROFS;
+ }
+
+ idx = vol_id2idx(ubi, vol_id);
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ ubi_assert(eba_tbl[idx].recs);
+ to_put = eba_tbl[idx].leb_count;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ for (i = 0; i < to_put; i++) {
+ err = ubi_eba_unmap_leb(ubi, vol_id, i);
+ if (err)
+ break;
+ }
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ rm_ebs = eba_tbl[idx].recs;
+ eba_tbl[idx].recs = NULL;
+ eba_tbl[idx].leb_count = 0;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ kfree(rm_ebs);
+ return err;
+}
+
+/**
+ * ubi_eba_rsvol - re-size EBA mapping for a volume.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: ID of the volume to be re-sized
+ * @reserved_pebs: new count of physical eraseblocks in this volume
+ *
+ * This function changes the EBA table accordingly to the volume re-size
+ * operation. If the volume is actually shrunken, the dropped logical
+ * eraseblocks are got unmapped an thus, the corresponding physical eraseblocks
+ * are scheduled for erasure. This function returns zero in case of success and
+ * a negative error code in case of failure.
+ */
+int ubi_eba_rsvol(struct ubi_info *ubi, int vol_id, int reserved_pebs)
+{
+ int err = 0, i, idx, min, to_put, sz;
+ struct ubi_eba_tbl_rec *new_ebs, *old_ebs;
+ struct ubi_eba_tbl_volume *eba_tbl = ubi->eba.eba_tbl;
+
+ dbg_eba("re-size volume %d to %d PEBs", vol_id, reserved_pebs);
+
+ ubi_assert(vol_id >= 0);
+ ubi_assert(!ubi_is_ivol(vol_id));
+ ubi_assert(vol_id < ubi->vtbl.vt_slots);
+ ubi_assert(reserved_pebs > 0);
+
+ if (ubi->io.ro_mode) {
+ dbg_err("read-only mode");
+ return -EROFS;
+ }
+
+ sz = reserved_pebs * sizeof(struct ubi_eba_tbl_rec);
+ new_ebs = kmalloc(sz, GFP_KERNEL);
+ if (!new_ebs)
+ return -ENOMEM;
+
+ for (i = 0; i < reserved_pebs; i++) {
+ new_ebs[i].pnum = NOT_MAPPED;
+ new_ebs[i].leb_ver = 0;
+ }
+
+ idx = vol_id2idx(ubi, vol_id);
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ ubi_assert(eba_tbl[idx].recs);
+
+ if (reserved_pebs < eba_tbl[idx].leb_count) {
+ min = reserved_pebs;
+ to_put = eba_tbl[idx].leb_count - reserved_pebs;
+ } else {
+ min = eba_tbl[idx].leb_count;
+ to_put = 0;
+ }
+
+ for (i = 0; i < min; i++) {
+ new_ebs[i].pnum = eba_tbl[idx].recs[i].pnum;
+ new_ebs[i].leb_ver = eba_tbl[idx].recs[i].leb_ver;
+ }
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ for (i = 0; i < to_put; i++) {
+ err = ubi_eba_unmap_leb(ubi, vol_id, i);
+ if (err)
+ break;
+ }
+
+ spin_lock(&ubi->eba.eba_tbl_lock);
+ old_ebs = eba_tbl[idx].recs;
+ eba_tbl[idx].recs = new_ebs;
+ eba_tbl[idx].leb_count = reserved_pebs;
+ spin_unlock(&ubi->eba.eba_tbl_lock);
+
+ kfree(old_ebs);
+ return err;
+}
+
+/**
+ * ltree_lookup - look up the lock tree.
+ *
+ * @eba: the EBA unit description data structure
+ * @vol_id: volume ID of the logical eraseblock to look up
+ * @lnum: the logical eraseblock to look up
+ *
+ * This function returns a pointer to the corresponding
+ * &struct ubi_eba_ltree_entry object if the logical eraseblock is locked and
+ * %NULL if it is not. The @ubi->eba.ltree_lock has to be locked.
+ */
+static struct ubi_eba_ltree_entry *ltree_lookup(struct ubi_info *ubi,
+ int vol_id, int lnum)
+{
+ struct rb_node *p;
+
+ p = ubi->eba.ltree.rb_node;
+ while (p) {
+ struct ubi_eba_ltree_entry *le;
+
+ le = rb_entry(p, struct ubi_eba_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: the UBI device description object
+ * @vol_id: volume ID of the logical eraseblock
+ * @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 a pointer to the lock tree entry or %-ENOMEM if memory allocation
+ * failed.
+ */
+static struct ubi_eba_ltree_entry *ltree_add_entry(struct ubi_info *ubi,
+ int vol_id, int lnum)
+{
+ struct ubi_eba_ltree_entry *le, *le1, *le_free;
+
+ le = kmem_cache_alloc(eba_ltree_entry_slab, GFP_KERNEL);
+ if (unlikely(!le))
+ return ERR_PTR(-ENOMEM);
+
+ le->vol_id = vol_id;
+ le->lnum = lnum;
+
+ spin_lock(&ubi->eba.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->eba.ltree RB-tree.
+ */
+ le_free = NULL;
+
+ p = &ubi->eba.ltree.rb_node;
+ while (*p) {
+ parent = *p;
+ le1 = rb_entry(parent, struct ubi_eba_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->eba.ltree);
+ }
+ le->users += 1;
+ spin_unlock(&ubi->eba.ltree_lock);
+
+ if (le_free)
+ kmem_cache_free(eba_ltree_entry_slab, le_free);
+
+ return le;
+}
+
+/**
+ * leb_read_lock - lock logical eraseblock for reading.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: volume ID
+ * @lnum: the logical eraseblock to lock
+ *
+ * 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_info *ubi, int vol_id, int lnum)
+{
+ struct ubi_eba_ltree_entry *le;
+
+ le = ltree_add_entry(ubi, vol_id, lnum);
+ if (unlikely(IS_ERR(le)))
+ return PTR_ERR(le);
+ down_read(&le->mutex);
+ return 0;
+}
+
+/**
+ * leb_read_unlock - unlock logical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: volume ID
+ * @lnum: the logical eraseblock to unlock
+ */
+static void leb_read_unlock(struct ubi_info *ubi, int vol_id, int lnum)
+{
+ int free = 0;
+ struct ubi_eba_ltree_entry *le;
+
+ spin_lock(&ubi->eba.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->eba.ltree);
+ free = 1;
+ }
+ spin_unlock(&ubi->eba.ltree_lock);
+
+ up_read(&le->mutex);
+ if (free)
+ kmem_cache_free(eba_ltree_entry_slab, le);
+}
+
+/**
+ * leb_write_lock - lock logical eraseblock for writing.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: volume ID
+ * @lnum: the logical eraseblock to lock
+ *
+ * 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_info *ubi, int vol_id, int lnum)
+{
+ struct ubi_eba_ltree_entry *le;
+
+ le = ltree_add_entry(ubi, vol_id, lnum);
+ if (unlikely(IS_ERR(le)))
+ return PTR_ERR(le);
+ down_write(&le->mutex);
+ return 0;
+}
+
+/**
+ * leb_write_unlock - unlock logical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: volume ID
+ * @lnum: the logical eraseblock to unlock
+ */
+static void leb_write_unlock(struct ubi_info *ubi, int vol_id, int lnum)
+{
+ int free;
+ struct ubi_eba_ltree_entry *le;
+
+ spin_lock(&ubi->eba.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->eba.ltree);
+ free = 1;
+ } else
+ free = 0;
+ spin_unlock(&ubi->eba.ltree_lock);
+
+ up_write(&le->mutex);
+ if (free)
+ kmem_cache_free(eba_ltree_entry_slab, le);
+}
+
+/**
+ * ubi_eba_unmap_leb - un-map a logical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: volume ID
+ * @lnum: the logical eraseblock to erase
+ *
+ * This function un-maps the logical eraseblock 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_info *ubi, int vol_id, int lnum)
+{
+ int err, pnum;
+
+ ubi_assert(vol_id >= 0);
+ ubi_assert(vol_id < ubi->vtbl.vt_slots || ubi_is_ivol(vol_id));
+ ubi_assert(lnum >= 0);
+ ubi_assert(ubi->eba.eba_tbl[vol_id2idx(ubi, vol_id)].recs);
+ ubi_assert(lnum < ubi->eba.eba_tbl[vol_id2idx(ubi, vol_id)].leb_count);
+
+ cond_resched();
+
+ if (unlikely(ubi->io.ro_mode)) {
+ dbg_err("read-only mode");
+ return -EROFS;
+ }
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (unlikely(err))
+ return err;
+
+ pnum = leb2peb(ubi, vol_id, lnum);
+ if (pnum < 0) {
+ /* This logical eraseblock is already unmapped */
+ dbg_eba("erase LEB %d:%d (unmapped)", vol_id, lnum);
+ goto out_unlock;
+ }
+ dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
+
+ leb_unmap(ubi, vol_id, lnum);
+
+ 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 from a logical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: volume ID from where to read
+ * @lnum: the logical eraseblock to read from
+ * @buf: buffer to store the read data
+ * @offset: offset within the logical eraseblock 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,
+ * id 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_info *ubi, int vol_id, int lnum, void *buf,
+ int offset, int len, int check)
+{
+ int err, pnum, scrub = 0;
+ const struct ubi_vtbl_vtr *vtr;
+ uint32_t data_crc;
+ struct ubi_vid_hdr *vid_hdr;
+
+ ubi_assert(vol_id >= 0);
+ ubi_assert(vol_id < ubi->vtbl.vt_slots || ubi_is_ivol(vol_id));
+ ubi_assert(lnum >= 0);
+ ubi_assert(offset >= 0);
+ ubi_assert(len > 0);
+
+ vtr = ubi_vtbl_get_vtr(ubi, vol_id);
+ ubi_assert(!IS_ERR(vtr));
+ ubi_assert(offset + len <= ubi->io.leb_size - vtr->data_pad);
+ ubi_assert(lnum < ubi->eba.eba_tbl[vol_id2idx(ubi, vol_id)].leb_count);
+
+ cond_resched();
+
+ err = leb_read_lock(ubi, vol_id, lnum);
+ if (unlikely(err))
+ return err;
+
+ pnum = leb2peb(ubi, vol_id, lnum);
+
+ if (pnum < 0) {
+ /*
+ * The logical eraseblock is not mapped, fill the whole buffer
+ * by 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(vtr->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 (vtr->vol_type == UBI_DYNAMIC_VOLUME)
+ /* In case of dynamic volumes no checking is needed */
+ check = 0;
+
+ if (check) {
+ vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ if (unlikely(!vid_hdr)) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
+ if (unlikely(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 (unlikely(err == UBI_IO_BITFLIPS))
+ scrub = 1;
+
+ err = paranoid_check_leb(ubi, pnum, vol_id, lnum, vid_hdr);
+ if (unlikely(err)) {
+ if (err > 0)
+ err = -EINVAL;
+ goto out_free;
+ }
+
+ ubi_assert(lnum < ubi32_to_cpu(vid_hdr->used_ebs));
+ ubi_assert(len == ubi32_to_cpu(vid_hdr->data_size));
+
+ data_crc = ubi32_to_cpu(vid_hdr->data_crc);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ }
+
+ err = ubi_io_read_data(ubi, buf, pnum, offset, len);
+ if (unlikely(err) && err != UBI_IO_BITFLIPS)
+ goto out_unlock;
+ else if (unlikely(err == UBI_IO_BITFLIPS)) {
+ scrub = 1;
+ err = 0;
+ }
+
+ if (check) {
+ uint32_t crc;
+
+ crc = crc32(UBI_CRC32_INIT, buf, len);
+ if (unlikely(crc != data_crc)) {
+ ubi_warn("CRC error: calculated %#08x, must be %#08x",
+ crc, data_crc);
+ err = -EBADMSG;
+ goto out_unlock;
+ }
+
+ if (err)
+ dbg_eba("error %d while reading, but data CRC is OK, "
+ "ignore the error", err);
+ err = 0;
+ dbg_eba("data is OK, CRC matches");
+ }
+
+ if (unlikely(err))
+ goto out_unlock;
+
+ if (unlikely(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: the 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 a 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
+ * foam 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.
+ */
+int recover_peb(struct ubi_info *ubi, int pnum, int vol_id, int lnum,
+ const void *buf, int offset, int len)
+{
+ int err, new_pnum, data_size, tries = 0;
+ struct ubi_vid_hdr *vid_hdr;
+ unsigned char *new_buf;
+
+ ubi_assert(ubi->io.bad_allowed);
+
+retry:
+ new_pnum = ubi_wl_get_peb(ubi, UBI_DATA_UNKNOWN);
+ if (new_pnum < 0)
+ return new_pnum;
+
+ ubi_msg("recover PEB %d, move data to PEB %d", pnum, new_pnum);
+
+ /* At first recover the VID header */
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ if (!vid_hdr) {
+ err = -ENOMEM;
+ goto out_put;
+ }
+
+ err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
+ if (err && err != UBI_IO_BITFLIPS) {
+ if (err > 0)
+ err = -EIO;
+ goto out_free;
+ }
+
+ vid_hdr->leb_ver = cpu_to_ubi32(ubi32_to_cpu(vid_hdr->leb_ver) + 1);
+ err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
+ if (err)
+ goto write_error;
+
+ /* Now recover the data */
+
+ data_size = offset + len;
+ new_buf = kmalloc(data_size, GFP_KERNEL);
+ if (unlikely(!new_buf)) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+ memset(new_buf + offset, 0xFF, len);
+
+ /* Read everything before the area where the write failure happened */
+ if (offset > 0) {
+ err = ubi_io_read_data(ubi, new_buf, pnum, 0, offset);
+ if (err && err != UBI_IO_BITFLIPS) {
+ kfree(new_buf);
+ goto out_free;
+ }
+ }
+
+ /*
+ * Now we assume that before the failed write the (offset, offset+len)
+ * area contained all 0xFF bytes. This is true for NAND. This is not
+ * always true for NOR, but NOR don't admit of bad PEBs.
+ */
+ memcpy(new_buf + offset, buf, len);
+
+ err = ubi_io_write_data(ubi, new_buf, new_pnum, 0, data_size);
+ if (err) {
+ kfree(new_buf);
+ goto write_error;
+ }
+
+ kfree(new_buf);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ ubi_eba_leb_remap(ubi, vol_id, lnum, new_pnum);
+ ubi_wl_put_peb(ubi, pnum, 1);
+ ubi_msg("data was successfully recovered");
+ return 0;
+
+out_free:
+ ubi_free_vid_hdr(ubi, vid_hdr);
+out_put:
+ ubi_wl_put_peb(ubi, new_pnum, 1);
+ 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_free_vid_hdr(ubi, vid_hdr);
+ ubi_wl_put_peb(ubi, new_pnum, 1);
+ if (++tries > 5)
+ /* We've tried too many times */
+ return err;
+ ubi_msg("try again");
+ goto retry;
+}
+
+/**
+ * ubi_eba_write_leb - write data to logical eraseblock of a dynamic volume.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID where to write
+ * @lnum: the logical eraseblock number to write
+ * @buf: the data to write
+ * @offset: the 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_id. Returns zero in case of success and a negative error code in case
+ * of failure. In case of an 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_info *ubi, int vol_id, int lnum,
+ const void *buf, int offset, int len,
+ enum ubi_data_type dtype)
+{
+ int err, pnum, tries = 0;
+ uint32_t leb_ver;
+ uint64_t sqnum;
+ struct ubi_vid_hdr *vid_hdr;
+ const struct ubi_vtbl_vtr *vtr;
+
+retry:
+ ubi_assert(vol_id >= 0);
+ ubi_assert(vol_id < ubi->vtbl.vt_slots || ubi_is_ivol(vol_id));
+ ubi_assert(lnum >= 0);
+ ubi_assert(offset >= 0);
+ ubi_assert(len >= 0);
+ ubi_assert(dtype == UBI_DATA_LONGTERM || dtype == UBI_DATA_SHORTTERM ||
+ dtype == UBI_DATA_UNKNOWN);
+
+ vtr = ubi_vtbl_get_vtr(ubi, vol_id);
+ ubi_assert(!IS_ERR(vtr));
+ ubi_assert(offset + len <= ubi->io.leb_size - vtr->data_pad);
+ ubi_assert(lnum < ubi->eba.eba_tbl[vol_id2idx(ubi, vol_id)].leb_count);
+ ubi_assert(len % ubi->io.min_io_size == 0);
+ ubi_assert(offset % ubi->io.min_io_size == 0);
+ ubi_assert(vtr->vol_type == UBI_DYNAMIC_VOLUME);
+
+ cond_resched();
+
+ if (unlikely(ubi->io.ro_mode)) {
+ dbg_err("read-only mode");
+ return -EROFS;
+ }
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (unlikely(err))
+ return err;
+
+ pnum = leb2peb(ubi, vol_id, lnum);
+ if (pnum >= 0) {
+ dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
+ len, offset, vol_id, lnum, pnum);
+
+ if (len != 0) {
+ err = ubi_io_write_data(ubi, buf, pnum, offset, len);
+ if (unlikely(err))
+ goto data_write_error;
+ }
+ 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);
+ if (unlikely(!vid_hdr)) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ sqnum = next_sqnum(ubi);
+ leb_ver = leb_get_ver(ubi, vol_id, lnum);
+
+ vid_hdr->vol_type = UBI_VID_DYNAMIC;
+ vid_hdr->sqnum = cpu_to_ubi64(sqnum);
+ vid_hdr->leb_ver = cpu_to_ubi32(leb_ver);
+ vid_hdr->vol_id = cpu_to_ubi32(vol_id);
+ vid_hdr->lnum = cpu_to_ubi32(lnum);
+ vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+ vid_hdr->data_pad = cpu_to_ubi32(vtr->data_pad);
+
+ pnum = ubi_wl_get_peb(ubi, dtype);
+ if (unlikely(pnum < 0)) {
+ err = pnum;
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ goto out_unlock;
+ }
+
+ 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 (unlikely(err)) {
+ ubi_warn("failed to write VID header to PEB %d", pnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ if (err != -EIO || !ubi->io.bad_allowed)
+ goto no_bad_eraseblocks;
+
+ /*
+ * Fortunately, we did not write any data there yet, so just put this
+ * physical eraseblock and request a new one. We assume that if this
+ * physical eraseblock went bad, the erase code will handle that.
+ */
+ ubi_msg("try to recover form the error");
+ err = ubi_wl_put_peb(ubi, pnum, 1);
+ leb_write_unlock(ubi, vol_id, lnum);
+ if (err || ++tries > 5) {
+ ubi_ro_mode(ubi);
+ return err;
+ }
+ goto retry;
+ }
+
+ leb_map(ubi, vol_id, lnum, pnum);
+
+ if (len != 0) {
+ err = ubi_io_write_data(ubi, buf, pnum, offset, len);
+ if (unlikely(err)) {
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ goto data_write_error;
+ }
+ }
+
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return 0;
+
+out_unlock:
+ leb_write_unlock(ubi, vol_id, lnum);
+ return err;
+
+ /* Failed to write data */
+data_write_error:
+ ubi_warn("failed to write data to PEB %d", pnum);
+ if (err != -EIO || !ubi->io.bad_allowed)
+ goto no_bad_eraseblocks;
+
+ 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;
+
+ /*
+ * This flash device does not admit of bad eraseblocks or something
+ * nasty and unexpected happened. Switch to read-only mode just in
+ * case.
+ */
+no_bad_eraseblocks:
+ ubi_ro_mode(ubi);
+ leb_write_unlock(ubi, vol_id, lnum);
+ return err;
+}
+
+/**
+ * ubi_eba_write_leb_st - write data to a logical eraseblock of a static
+ * volume.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID where to write
+ * @lnum: the logical eraseblock number to write
+ * @buf: the data to write
+ * @len: how many bytes to write
+ * @dtype: data type
+ * @used_ebs: how many logical eraseblocks will this volume contain (used only
+ * for static volumes)
+ *
+ * This function writes data to a logical eraseblock of a static volume. The
+ * @used_ebs argument should contain total number of logical eraseblock which
+ * will contain any data in this static volume.
+ *
+ * When writing to the last logical eraseblock of a static volume, 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.
+ *
+ * Note, 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_info *ubi, int vol_id, int lnum,
+ const void *buf, int len, enum ubi_data_type dtype,
+ int used_ebs)
+{
+ int err, pnum, tries = 0, data_size = len;
+ uint32_t leb_ver, crc;
+ uint64_t sqnum;
+ struct ubi_vid_hdr *vid_hdr;
+ const struct ubi_vtbl_vtr *vtr;
+
+retry:
+ ubi_assert(vol_id >= 0);
+ ubi_assert(vol_id < ubi->vtbl.vt_slots || ubi_is_ivol(vol_id));
+ ubi_assert(lnum >= 0);
+ ubi_assert(len > 0);
+ ubi_assert(dtype == UBI_DATA_LONGTERM || dtype == UBI_DATA_SHORTTERM ||
+ dtype == UBI_DATA_UNKNOWN);
+
+ vtr = ubi_vtbl_get_vtr(ubi, vol_id);
+ ubi_assert(!IS_ERR(vtr));
+ ubi_assert(lnum < ubi->eba.eba_tbl[vol_id2idx(ubi, vol_id)].leb_count);
+ ubi_assert(lnum < used_ebs);
+ ubi_assert(used_ebs >= 0);
+ ubi_assert(vtr->vol_type == UBI_STATIC_VOLUME);
+
+ cond_resched();
+
+ if (lnum == used_ebs - 1) {
+ /*
+ * If this is the last logical eraseblock of a static
+ * volume, @len may be unaligned.
+ */
+ ubi_assert(len <= ubi->io.leb_size - vtr->data_pad);
+ len = align_up(data_size, ubi->io.min_io_size);
+ } else {
+ ubi_assert(len == ubi->io.leb_size - vtr->data_pad);
+ ubi_assert(len % ubi->io.min_io_size == 0);
+ }
+
+ if (unlikely(ubi->io.ro_mode)) {
+ dbg_err("read-only mode");
+ return -EROFS;
+ }
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (unlikely(err))
+ return err;
+
+ ubi_assert(leb2peb(ubi, vol_id, lnum) < 0);
+
+ /*
+ * Get a free physical eraseblock and write the volume identifier
+ * header.
+ */
+ vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ if (unlikely(!vid_hdr)) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ sqnum = next_sqnum(ubi);
+ leb_ver = leb_get_ver(ubi, vol_id, lnum);
+
+ vid_hdr->sqnum = cpu_to_ubi64(sqnum);
+ vid_hdr->leb_ver = cpu_to_ubi32(leb_ver);
+ vid_hdr->vol_id = cpu_to_ubi32(vol_id);
+ vid_hdr->lnum = cpu_to_ubi32(lnum);
+ vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+ vid_hdr->data_pad = cpu_to_ubi32(vtr->data_pad);
+
+ crc = crc32(UBI_CRC32_INIT, buf, data_size);
+ vid_hdr->vol_type = UBI_VID_STATIC;
+ vid_hdr->data_size = cpu_to_ubi32(data_size);
+ vid_hdr->used_ebs = cpu_to_ubi32(used_ebs);
+ vid_hdr->data_crc = cpu_to_ubi32(crc);
+
+ pnum = ubi_wl_get_peb(ubi, dtype);
+ if (unlikely(pnum < 0)) {
+ err = pnum;
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ goto out_unlock;
+ }
+
+ dbg_eba("write VID hdr and %d bytes at of LEB %d:%d, PEB %d",
+ len, vol_id, lnum, pnum);
+
+ err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
+ if (unlikely(err)) {
+ ubi_warn("failed to write VID header to PEB %d", pnum);
+ goto write_error;
+ }
+
+ leb_map(ubi, vol_id, lnum, pnum);
+
+ err = ubi_io_write_data(ubi, buf, pnum, 0, len);
+ if (unlikely(err)) {
+ ubi_warn("failed to write data to PEB %d", pnum);
+ goto write_error;
+ }
+
+ leb_write_unlock(ubi, vol_id, lnum);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return 0;
+
+out_unlock:
+ leb_write_unlock(ubi, vol_id, lnum);
+ return err;
+
+ /* Write failure */
+write_error:
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ if (err != -EIO || !ubi->io.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);
+ return err;
+ }
+
+ /*
+ * We assume that if this physical eraseblock went bad - the erase code
+ * will handle that.
+ */
+ ubi_msg("try to recover form the error");
+ err = ubi_wl_put_peb(ubi, pnum, 1);
+ leb_write_unlock(ubi, vol_id, lnum);
+ if (err || ++tries > 5) {
+ ubi_ro_mode(ubi);
+ return err;
+ }
+ goto retry;
+}
+
+/**
+ * ubi_eba_leb_is_mapped - check if a logical eraseblock is mapped.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: volume ID
+ * @lnum: the logical eraseblock to check
+ *
+ * This function checks if logical eraseblock @lnum is mapped to a physical
+ * eraseblock. Returns %1 if it is mapped, and %0 if not.
+ */
+int ubi_eba_leb_is_mapped(struct ubi_info *ubi, int vol_id, int lnum)
+{
+ dbg_eba("check LEB %d:%d PEBs", vol_id, lnum);
+
+ ubi_assert(vol_id >= 0 && vol_id < ubi->vtbl.vt_slots);
+ ubi_assert(lnum >= 0);
+ ubi_assert(lnum < ubi->eba.eba_tbl[vol_id2idx(ubi, vol_id)].leb_count);
+
+ return leb2peb(ubi, vol_id, lnum) >= 0;
+}
+
+/**
+ * ubi_eba_leb_remap - re-map a logical eraseblock to another physical
+ * eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID
+ * @lnum: the logical eraseblock number
+ * @pnum: new physical eraseblock to map to
+ *
+ * The logical eraseblock must be locked before re-mapping.
+ */
+void ubi_eba_leb_remap(struct ubi_info *ubi, int vol_id, int lnum, int pnum)
+{
+ /* The logical eraseblock is supposed to be locked */
+ paranoid_check_leb_locked(ubi, vol_id, lnum);
+ leb_unmap(ubi, vol_id, lnum);
+ leb_map(ubi, vol_id, lnum, pnum);
+}
+
+/**
+ * build_eba_tbl - build the eraseblock association table.
+ *
+ * @ubi: the UBI device description object
+ * @si: scanning info
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int build_eba_tbl(const struct ubi_info *ubi,
+ const struct ubi_scan_info *si)
+{
+ int i, err, idx;
+ struct ubi_eba_tbl_volume *eba_tbl = ubi->eba.eba_tbl;
+
+ for (idx = 0; idx < ubi->eba.num_volumes; idx++) {
+ struct rb_node *rb;
+ struct ubi_scan_leb *seb;
+ struct ubi_scan_volume *sv;
+ const struct ubi_vtbl_vtr *vtr;
+ int sz;
+
+ cond_resched();
+
+ vtr = ubi_vtbl_get_vtr(ubi, idx2vol_id(ubi, idx));
+ if (IS_ERR(vtr))
+ continue;
+
+ dbg_eba("found volume %d (idx %d)", idx2vol_id(ubi, idx), idx);
+
+ eba_tbl[idx].leb_count = vtr->reserved_pebs;
+
+ sz = vtr->reserved_pebs * sizeof(struct ubi_eba_tbl_rec);
+ eba_tbl[idx].recs = kmalloc(sz, GFP_KERNEL);
+ if (unlikely(!eba_tbl[idx].recs)) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ for (i = 0; i < vtr->reserved_pebs; i++) {
+ ubi->eba.eba_tbl[idx].recs[i].pnum = NOT_MAPPED;
+ ubi->eba.eba_tbl[idx].recs[i].leb_ver = 0;
+ }
+
+ sv = ubi_scan_find_sv(si, idx2vol_id(ubi, idx));
+ if (!sv)
+ continue;
+
+ rb_for_each_entry(rb, seb, &sv->root, u.rb) {
+ ubi->eba.eba_tbl[idx].recs[seb->lnum].pnum = seb->pnum;
+ ubi->eba.eba_tbl[idx].recs[seb->lnum].leb_ver
+ = seb->leb_ver + 100;
+ }
+ }
+
+ return 0;
+
+out:
+ for (i = 0; i < ubi->eba.num_volumes; i++)
+ kfree(ubi->eba.eba_tbl[i].recs);
+
+ return err;
+}
+
+/**
+ * ltree_entry_ctor - lock tree entries slab cache constructor.
+ *
+ * @obj: the lock-tree entry to construct
+ * @cache: the lock tree entry slab cache
+ * @flag: constructor flags
+ */
+static void ltree_entry_ctor(void *obj, struct kmem_cache *cache,
+ unsigned long flags)
+{
+ struct ubi_eba_ltree_entry *le = obj;
+
+ if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) !=
+ SLAB_CTOR_CONSTRUCTOR)
+ return;
+
+ le->users = 0;
+ init_rwsem(&le->mutex);
+}
+
+/**
+ * ubi_eba_init_scan - initialize the EBA unit using scanning information.
+ *
+ * @ubi: the UBI device description object
+ * @si: pointer to the 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_info *ubi, struct ubi_scan_info *si)
+{
+ int err, sz;
+
+ dbg_eba("initialize the EBA unit");
+
+ spin_lock_init(&ubi->eba.eba_tbl_lock);
+ spin_lock_init(&ubi->eba.ltree_lock);
+ ubi->eba.ltree = RB_ROOT;
+
+ if (ubis_num == 0) {
+ eba_ltree_entry_slab =
+ kmem_cache_create("ubi_eba_ltree_entry_slab",
+ sizeof(struct ubi_eba_ltree_entry), 0,
+ 0, &ltree_entry_ctor, NULL);
+ if (!eba_ltree_entry_slab)
+ return -ENOMEM;
+ }
+
+ ubi->eba.global_sq_cnt = si->max_sqnum;
+
+ ubi->eba.num_volumes = ubi->vtbl.vt_slots + UBI_INT_VOL_COUNT;
+ sz = ubi->eba.num_volumes * sizeof(struct ubi_eba_tbl_volume);
+ ubi->eba.eba_tbl = kzalloc(sz, GFP_KERNEL);
+ if (!ubi->eba.eba_tbl)
+ goto out;
+
+ err = build_eba_tbl(ubi, si);
+ if (err)
+ goto out;
+
+ dbg_eba("the EBA unit is initialized");
+ return 0;
+
+out:
+ kfree(ubi->eba.eba_tbl);
+ if (ubis_num == 0)
+ kmem_cache_destroy(eba_ltree_entry_slab);
+ return err;
+}
+
+/**
+ * ubi_eba_close - close the EBA unit.
+ *
+ * @ubi: the UBI device description object
+ */
+void ubi_eba_close(const struct ubi_info *ubi)
+{
+ unsigned int i;
+
+ dbg_eba("close EBA management unit");
+
+ for (i = 0; i < ubi->eba.num_volumes; i++)
+ kfree(ubi->eba.eba_tbl[i].recs);
+ if (ubis_num == 1)
+ kmem_cache_destroy(eba_ltree_entry_slab);
+}
+
+/**
+ * ubi_eba_copy_leb - copy logical eraseblock.
+ *
+ * @ubi: the UBI device description object
+ * @from: physical eraseblock number from where to move
+ * @to: physical eraseblock number where to move
+ * @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 zero in case of success, %UBI_IO_BITFLIPS if the operation
+ * was canceled because bit-flips were detected at the target PEB, and a
+ * negative error code in case of failure.
+ */
+int ubi_eba_copy_leb(struct ubi_info *ubi, int from, int to,
+ struct ubi_vid_hdr *vid_hdr)
+{
+ int err, vol_id, lnum, data_size, aldata_size, pnum;
+ uint32_t crc;
+ unsigned long long sqnum;
+ void *buf;
+
+ vol_id = ubi32_to_cpu(vid_hdr->vol_id);
+ lnum = ubi32_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 = ubi32_to_cpu(vid_hdr->data_size);
+ aldata_size = align_up(data_size, ubi->io.min_io_size);
+ } else
+ data_size = aldata_size =
+ ubi->io.leb_size - ubi32_to_cpu(vid_hdr->data_pad);
+
+ ubi_assert(aldata_size % ubi->io.min_io_size == 0);
+
+ buf = kmalloc(aldata_size, GFP_KERNEL);
+ if (unlikely(!buf))
+ return -ENOMEM;
+
+ /*
+ * We do not want anybody to write to this logical eraseblock while we
+ * are moving it, so we lock it.
+ */
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (unlikely(err))
+ goto out_free;
+
+ /*
+ * But the logical eraseblock might have been put by this time.
+ * Cancel if it is true.
+ */
+ pnum = leb2peb(ubi, vol_id, lnum);
+ if (pnum != from) {
+ dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
+ "PEB %d, cancel", vol_id, lnum, from, pnum);
+ goto out_unlock;
+ }
+
+ /*
+ * OK, now the LEB is locked and we can safely start moving it.
+ */
+
+ dbg_eba("read %d bytes of data", aldata_size);
+
+ err = ubi_io_read_data(ubi, buf, from, 0, aldata_size);
+ if (unlikely(err) && err != UBI_IO_BITFLIPS) {
+ ubi_warn("error %d while reading data from PEB %d",
+ err, from);
+ goto out_unlock;
+ }
+
+ /*
+ * 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, buf, data_size);
+
+ cond_resched();
+ crc = crc32(UBI_CRC32_INIT, buf, data_size);
+ cond_resched();
+
+ /*
+ * It may turn out 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 (likely(data_size > 0)) {
+ vid_hdr->copy_flag = 1;
+ vid_hdr->data_size = cpu_to_ubi32(data_size);
+ vid_hdr->data_crc = cpu_to_ubi32(crc);
+ }
+ vid_hdr->leb_ver = cpu_to_ubi32(ubi32_to_cpu(vid_hdr->leb_ver) + 1);
+ sqnum = next_sqnum(ubi);
+ vid_hdr->sqnum = cpu_to_ubi64(sqnum);
+
+ err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
+ if (unlikely(err))
+ goto out_unlock;
+
+ 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 (unlikely(err)) {
+ if (err != UBI_IO_BITFLIPS)
+ ubi_warn("cannot read VID header back from PEB %d", to);
+ goto out_unlock;
+ }
+
+ if (likely(data_size > 0)) {
+ void *buf1;
+
+ err = ubi_io_write_data(ubi, buf, to, 0, aldata_size);
+ if (unlikely(err))
+ goto out_unlock;
+
+ /*
+ * We've written the data and are going to read it back to make
+ * sure it was written correctly.
+ */
+ buf1 = kmalloc(aldata_size, GFP_KERNEL);
+ if (unlikely(!buf1)) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ cond_resched();
+
+ err = ubi_io_read_data(ubi, buf1, to, 0, aldata_size);
+ if (unlikely(err)) {
+ kfree(buf1);
+ if (err != UBI_IO_BITFLIPS)
+ ubi_warn("cannot read data back from PEB %d",
+ to);
+ goto out_unlock;
+ }
+
+ cond_resched();
+
+ if (unlikely(memcmp(buf, buf1, aldata_size))) {
+ ubi_warn("read data back from PEB %d - it is different",
+ to);
+ kfree(buf1);
+ goto out_unlock;
+ }
+ kfree(buf1);
+ }
+
+ ubi_eba_leb_remap(ubi, vol_id, lnum, to);
+ leb_write_unlock(ubi, vol_id, lnum);
+ kfree(buf);
+
+ return 0;
+
+out_unlock:
+ leb_write_unlock(ubi, vol_id, lnum);
+out_free:
+ kfree(buf);
+ return err;
+}
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID_EBA
+
+/**
+ * paranoid_check_leb - check that a logical eraseblock has correct erase
+ * counter and volume identifier headers.
+ *
+ * @ubi: the UBI device description object
+ * @pnum: the physical eraseblock number
+ * @vol_id: the volume ID to check
+ * @lnum: the logical eraseblock number to check
+ * @vid_hdr: volume identifier header to check
+ *
+ * This function returns zero if the headers are all right, %1 if not, and a
+ * negative error code in case of error.
+ */
+static int paranoid_check_leb(const struct ubi_info *ubi, int pnum, int vol_id,
+ int lnum, const struct ubi_vid_hdr *vid_hdr)
+{
+ int err, hdr_vol_id, hdr_lnum;
+ struct ubi_ec_hdr *ec_hdr;
+
+ /* Check the EC header */
+ ec_hdr = kzalloc(ubi->io.ec_hdr_alsize, GFP_KERNEL);
+ if (unlikely(!ec_hdr))
+ return -ENOMEM;
+
+ err = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 1);
+ kfree(ec_hdr);
+ if (unlikely(err) && err != UBI_IO_BITFLIPS) {
+ if (err < 0)
+ return err;
+ goto fail;
+ }
+
+ hdr_vol_id = ubi32_to_cpu(vid_hdr->vol_id);
+ hdr_lnum = ubi32_to_cpu(vid_hdr->lnum);
+
+ if (unlikely(vol_id != hdr_vol_id)) {
+ ubi_err("bad vol_id %d, should be %d", hdr_vol_id, vol_id);
+ goto fail;
+ }
+
+ if (unlikely(lnum != hdr_lnum)) {
+ ubi_err("bad lnum %d, should be %d", hdr_lnum, lnum);
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ ubi_err("paranoid check failed");
+ ubi_dbg_dump_stack();
+ return 1;
+}
+
+/**
+ * paranoid_check_leb_locked - ensure that a logical eraseblock is locked.
+ *
+ * @ubi: the UBI device description object
+ * @vol_id: the volume ID to check
+ * @lnum: the logical eraseblock number to check
+ *
+ * This function returns zero if the logical eraseblock is locked and %1 if
+ * not.
+ */
+static int paranoid_check_leb_locked(struct ubi_info *ubi, int vol_id, int lnum)
+{
+ struct ubi_eba_ltree_entry *le;
+
+ spin_lock(&ubi->eba.ltree_lock);
+ le = ltree_lookup(ubi, vol_id, lnum);
+ spin_unlock(&ubi->eba.ltree_lock);
+ if (likely(le))
+ return 0;
+
+ ubi_err("paranoid check failed");
+ ubi_dbg_dump_stack();
+ return 1;
+}
+
+#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID_EBA */