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Message-Id: <20070323164347.8958.62489.sendpatchset@localhost.localdomain>
Date: Fri, 23 Mar 2007 18:43:47 +0200
From: Artem Bityutskiy <dedekind@...radead.org>
To: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Cc: Frank Haverkamp <haver@...t.ibm.com>,
David Woodhouse <dwmw2@...radead.org>,
Josh Boyer <jwboyer@...ux.vnet.ibm.com>,
Artem Bityutskiy <dedekind@...radead.org>
Subject: [PATCH 10/20 take 4] UBI: EBA unit
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 2007-03-23 18:20:01.000000000 +0200
@@ -0,0 +1,1132 @@
+/*
+ * 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 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 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: 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 ltree_entry
+ * object is inserted to the lock tree (@ubi->ltree).
+ */
+struct ltree_entry {
+ struct rb_node rb;
+ int vol_id;
+ int lnum;
+ int users;
+ struct rw_semaphore mutex;
+};
+
+/* Slab cache for lock-tree entries */
+static struct kmem_cache *ltree_slab;
+
+/**
+ * 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_VOL_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 ltree_entry
+ * object if the logical eraseblock is locked and %NULL if it is not.
+ * @ubi->ltree_lock has to be locked.
+ */
+static struct 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 ltree_entry *le;
+
+ le = rb_entry(p, struct 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 ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id,
+ int lnum)
+{
+ struct ltree_entry *le, *le1, *le_free;
+
+ le = kmem_cache_alloc(ltree_slab, GFP_KERNEL);
+ if (unlikely(!le))
+ return ERR_PTR(-ENOMEM);
+
+ 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 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)
+ kmem_cache_free(ltree_slab, 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 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: 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 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)
+ kmem_cache_free(ltree_slab, 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 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: 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 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)
+ kmem_cache_free(ltree_slab, le);
+}
+
+/**
+ * ubi_eba_unmap_leb - un-map logical eraseblock.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @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, int vol_id, int lnum)
+{
+ int idx = vol_id2idx(ubi, vol_id), err, pnum;
+ struct ubi_volume *vol = ubi->volumes[idx];
+
+ if (unlikely(ubi->ro_mode))
+ return -EROFS;
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (unlikely(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_id: volume ID
+ * @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, int vol_id, int lnum, void *buf,
+ int offset, int len, int check)
+{
+ int err, pnum, scrub = 0, idx = vol_id2idx(ubi, vol_id);
+ struct ubi_vid_hdr *vid_hdr;
+ struct ubi_volume *vol = ubi->volumes[idx];
+ uint32_t crc, crc1;
+
+ err = leb_read_lock(ubi, vol_id, lnum);
+ if (unlikely(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);
+ 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;
+
+ ubi_assert(lnum < ubi32_to_cpu(vid_hdr->used_ebs));
+ ubi_assert(len == ubi32_to_cpu(vid_hdr->data_size));
+
+ 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)) {
+ 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) {
+ crc1 = crc32(UBI_CRC32_INIT, buf, len);
+ if (unlikely(crc1 != crc)) {
+ ubi_warn("CRC error: calculated %#08x, must be %#08x",
+ crc1, crc);
+ err = -EBADMSG;
+ 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: 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.
+ */
+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;
+ unsigned char *new_buf;
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ if (!vid_hdr) {
+ return -ENOMEM;
+ }
+
+retry:
+ new_pnum = ubi_wl_get_peb(ubi, UBI_DATA_UNKNOWN);
+ if (new_pnum < 0) {
+ 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_ubi64(next_sqnum(ubi));
+ err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
+ if (err)
+ goto write_error;
+
+ data_size = offset + len;
+ new_buf = kmalloc(data_size, GFP_KERNEL);
+ if (unlikely(!new_buf)) {
+ err = -ENOMEM;
+ goto out_put;
+ }
+ 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_put;
+ }
+ }
+
+ 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);
+
+ vol->eba_tbl[lnum] = new_pnum;
+ ubi_wl_put_peb(ubi, pnum, 1);
+
+ ubi_msg("data was successfully recovered");
+ return 0;
+
+out_put:
+ 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) {
+ 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_id: volume ID
+ * @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_id. 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, int vol_id, int lnum,
+ const void *buf, int offset, int len,
+ enum ubi_data_type dtype)
+{
+ int idx = vol_id2idx(ubi, vol_id), err, pnum, tries = 0;
+ struct ubi_volume *vol = ubi->volumes[idx];
+ struct ubi_vid_hdr *vid_hdr;
+
+ if (unlikely(ubi->ro_mode))
+ return -EROFS;
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (unlikely(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 (unlikely(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);
+ if (unlikely(!vid_hdr)) {
+ leb_write_unlock(ubi, vol_id, lnum);
+ return -ENOMEM;
+ }
+
+ vid_hdr->vol_type = UBI_VID_DYNAMIC;
+ vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
+ 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(vol->data_pad);
+
+retry:
+ pnum = ubi_wl_get_peb(ubi, dtype);
+ if (unlikely(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 (unlikely(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, offset, len);
+ if (unlikely(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_ubi64(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_id: volume ID
+ * @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_id. 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, 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;
+ int idx = vol_id2idx(ubi, vol_id);
+ struct ubi_volume *vol = ubi->volumes[idx];
+ struct ubi_vid_hdr *vid_hdr;
+ uint32_t crc;
+
+ if (unlikely(ubi->ro_mode))
+ return -EROFS;
+
+ if (lnum == used_ebs - 1)
+ /* If this is the last LEB @len may be unaligned */
+ len = ubi_align_up(data_size, ubi->min_io_size);
+ else
+ ubi_assert(len % ubi->min_io_size == 0);
+
+ vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ if (unlikely(!vid_hdr))
+ return -ENOMEM;
+
+ err = leb_write_lock(ubi, vol_id, lnum);
+ if (unlikely(err)) {
+ ubi_free_vid_hdr(ubi, vid_hdr);
+ return err;
+ }
+
+ vid_hdr->sqnum = cpu_to_ubi64(next_sqnum(ubi));
+ 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(vol->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);
+
+retry:
+ pnum = ubi_wl_get_peb(ubi, dtype);
+ if (unlikely(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 (unlikely(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 (unlikely(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_ubi64(next_sqnum(ubi));
+ ubi_msg("try another PEB");
+ goto retry;
+}
+
+/**
+ * ltree_entry_ctor - lock tree entries slab cache constructor.
+ * @obj: the lock-tree entry to construct
+ * @cache: the lock tree entry slab cache
+ * @flags: constructor flags
+ */
+static void ltree_entry_ctor(void *obj, struct kmem_cache *cache,
+ unsigned long flags)
+{
+ struct 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_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 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_device *ubi, int from, int to,
+ struct ubi_vid_hdr *vid_hdr)
+{
+ int err, vol_id, lnum, data_size, aldata_size, pnum, idx;
+ struct ubi_volume *vol;
+ uint32_t crc;
+ void *buf, *buf1 = NULL;
+
+ 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 = ubi_align_up(data_size, ubi->min_io_size);
+ } else
+ data_size = aldata_size =
+ ubi->leb_size - ubi32_to_cpu(vid_hdr->data_pad);
+
+ 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)) {
+ kfree(buf);
+ return err;
+ }
+
+ /*
+ * But the logical eraseblock might have been put by this time.
+ * Cancel if it is true.
+ */
+ idx = vol_id2idx(ubi, vol_id);
+
+ /*
+ * We may race with volume deletion/resize, so we have to hold
+ * @ubi->volumes_lock.
+ */
+ spin_lock(&ubi->volumes_lock);
+ vol = ubi->volumes[idx];
+ if (!vol) {
+ dbg_eba("volume %d was removed meanwhile", vol_id);
+ spin_unlock(&ubi->volumes_lock);
+ goto out_unlock;
+ }
+
+ pnum = vol->eba_tbl[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);
+ spin_unlock(&ubi->volumes_lock);
+ goto out_unlock;
+ }
+ spin_unlock(&ubi->volumes_lock);
+
+ /* 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 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 (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->sqnum = cpu_to_ubi64(next_sqnum(ubi));
+
+ 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)) {
+ 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)) {
+ 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);
+ goto out_unlock;
+ }
+ }
+
+ ubi_assert(vol->eba_tbl[lnum] == from);
+ vol->eba_tbl[lnum] = to;
+
+ leb_write_unlock(ubi, vol_id, lnum);
+ kfree(buf);
+ kfree(buf1);
+
+ return 0;
+
+out_unlock:
+ leb_write_unlock(ubi, vol_id, lnum);
+ kfree(buf);
+ kfree(buf1);
+ 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);
+ ubi->ltree = RB_ROOT;
+
+ if (ubi_devices_cnt == 0) {
+ ltree_slab = kmem_cache_create("ubi_ltree_slab",
+ sizeof(struct ltree_entry), 0,
+ 0, <ree_entry_ctor, NULL);
+ if (!ltree_slab)
+ return -ENOMEM;
+ }
+
+ 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 (unlikely(!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->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);
+ }
+ if (ubi_devices_cnt == 0)
+ kmem_cache_destroy(ltree_slab);
+ 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);
+ }
+ if (ubi_devices_cnt == 1)
+ kmem_cache_destroy(ltree_slab);
+}
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