diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mtd/ubi/upd.c | 441 | ||||
| -rw-r--r-- | drivers/mtd/ubi/vmt.c | 862 | ||||
| -rw-r--r-- | drivers/mtd/ubi/vtbl.c | 837 | ||||
| -rw-r--r-- | drivers/mtd/ubi/wl.c | 1670 |
4 files changed, 3810 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c new file mode 100644 index 0000000..5f7ed7b --- /dev/null +++ b/drivers/mtd/ubi/upd.c @@ -0,0 +1,441 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 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) + * + * Jan 2007: Alexander Schmidt, hacked per-volume update. + */ + +/* + * This file contains implementation of the volume update and atomic LEB change + * functionality. + * + * The update operation is based on the per-volume update marker which is + * stored in the volume table. The update marker is set before the update + * starts, and removed after the update has been finished. So if the update was + * interrupted by an unclean re-boot or due to some other reasons, the update + * marker stays on the flash media and UBI finds it when it attaches the MTD + * device next time. If the update marker is set for a volume, the volume is + * treated as damaged and most I/O operations are prohibited. Only a new update + * operation is allowed. + * + * Note, in general it is possible to implement the update operation as a + * transaction with a roll-back capability. + */ + +#ifdef UBI_LINUX +#include <linux/err.h> +#include <asm/uaccess.h> +#include <asm/div64.h> +#endif + +#include <ubi_uboot.h> +#include "ubi.h" + +/** + * set_update_marker - set update marker. + * @ubi: UBI device description object + * @vol: volume description object + * + * This function sets the update marker flag for volume @vol. Returns zero + * in case of success and a negative error code in case of failure. + */ +static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol) +{ + int err; + struct ubi_vtbl_record vtbl_rec; + + dbg_msg("set update marker for volume %d", vol->vol_id); + + if (vol->upd_marker) { + ubi_assert(ubi->vtbl[vol->vol_id].upd_marker); + dbg_msg("already set"); + return 0; + } + + memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id], + sizeof(struct ubi_vtbl_record)); + vtbl_rec.upd_marker = 1; + + mutex_lock(&ubi->volumes_mutex); + err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); + mutex_unlock(&ubi->volumes_mutex); + vol->upd_marker = 1; + return err; +} + +/** + * clear_update_marker - clear update marker. + * @ubi: UBI device description object + * @vol: volume description object + * @bytes: new data size in bytes + * + * This function clears the update marker for volume @vol, sets new volume + * data size and clears the "corrupted" flag (static volumes only). Returns + * zero in case of success and a negative error code in case of failure. + */ +static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol, + long long bytes) +{ + int err; + uint64_t tmp; + struct ubi_vtbl_record vtbl_rec; + + dbg_msg("clear update marker for volume %d", vol->vol_id); + + memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id], + sizeof(struct ubi_vtbl_record)); + ubi_assert(vol->upd_marker && vtbl_rec.upd_marker); + vtbl_rec.upd_marker = 0; + + if (vol->vol_type == UBI_STATIC_VOLUME) { + vol->corrupted = 0; + vol->used_bytes = tmp = bytes; + vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size); + vol->used_ebs = tmp; + if (vol->last_eb_bytes) + vol->used_ebs += 1; + else + vol->last_eb_bytes = vol->usable_leb_size; + } + + mutex_lock(&ubi->volumes_mutex); + err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); + mutex_unlock(&ubi->volumes_mutex); + vol->upd_marker = 0; + return err; +} + +/** + * ubi_start_update - start volume update. + * @ubi: UBI device description object + * @vol: volume description object + * @bytes: update bytes + * + * This function starts volume update operation. If @bytes is zero, the volume + * is just wiped out. Returns zero in case of success and a negative error code + * in case of failure. + */ +int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol, + long long bytes) +{ + int i, err; + uint64_t tmp; + + dbg_msg("start update of volume %d, %llu bytes", vol->vol_id, bytes); + ubi_assert(!vol->updating && !vol->changing_leb); + vol->updating = 1; + + err = set_update_marker(ubi, vol); + if (err) + return err; + + /* Before updating - wipe out the volume */ + for (i = 0; i < vol->reserved_pebs; i++) { + err = ubi_eba_unmap_leb(ubi, vol, i); + if (err) + return err; + } + + if (bytes == 0) { + err = clear_update_marker(ubi, vol, 0); + if (err) + return err; + err = ubi_wl_flush(ubi); + if (!err) + vol->updating = 0; + } + + vol->upd_buf = vmalloc(ubi->leb_size); + if (!vol->upd_buf) + return -ENOMEM; + + tmp = bytes; + vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size); + vol->upd_ebs += tmp; + vol->upd_bytes = bytes; + vol->upd_received = 0; + return 0; +} + +/** + * ubi_start_leb_change - start atomic LEB change. + * @ubi: UBI device description object + * @vol: volume description object + * @req: operation request + * + * This function starts atomic LEB change operation. Returns zero in case of + * success and a negative error code in case of failure. + */ +int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, + const struct ubi_leb_change_req *req) +{ + ubi_assert(!vol->updating && !vol->changing_leb); + + dbg_msg("start changing LEB %d:%d, %u bytes", + vol->vol_id, req->lnum, req->bytes); + if (req->bytes == 0) + return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0, + req->dtype); + + vol->upd_bytes = req->bytes; + vol->upd_received = 0; + vol->changing_leb = 1; + vol->ch_lnum = req->lnum; + vol->ch_dtype = req->dtype; + + vol->upd_buf = vmalloc(req->bytes); + if (!vol->upd_buf) + return -ENOMEM; + + return 0; +} + +/** + * write_leb - write update data. + * @ubi: UBI device description object + * @vol: volume description object + * @lnum: logical eraseblock number + * @buf: data to write + * @len: data size + * @used_ebs: how many logical eraseblocks will this volume contain (static + * volumes only) + * + * This function writes update data to corresponding logical eraseblock. In + * case of dynamic volume, this function checks if the data contains 0xFF bytes + * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole + * buffer contains only 0xFF bytes, the LEB is left unmapped. + * + * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is + * that we want to make sure that more data may be appended to the logical + * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and + * this PEB won't be writable anymore. So if one writes the file-system image + * to the UBI volume where 0xFFs mean free space - UBI makes sure this free + * space is writable after the update. + * + * We do not do this for static volumes because they are read-only. But this + * also cannot be done because we have to store per-LEB CRC and the correct + * data length. + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, + void *buf, int len, int used_ebs) +{ + int err; + + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + int l = ALIGN(len, ubi->min_io_size); + + memset(buf + len, 0xFF, l - len); + len = ubi_calc_data_len(ubi, buf, l); + if (len == 0) { + dbg_msg("all %d bytes contain 0xFF - skip", len); + return 0; + } + + err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len, UBI_UNKNOWN); + } else { + /* + * When writing static volume, and this is the last logical + * eraseblock, the length (@len) does not have to be aligned to + * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()' + * function accepts exact (unaligned) length and stores it in + * the VID header. And it takes care of proper alignment by + * padding the buffer. Here we just make sure the padding will + * contain zeros, not random trash. + */ + memset(buf + len, 0, vol->usable_leb_size - len); + err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len, + UBI_UNKNOWN, used_ebs); + } + + return err; +} + +/** + * ubi_more_update_data - write more update data. + * @vol: volume description object + * @buf: write data (user-space memory buffer) + * @count: how much bytes to write + * + * This function writes more data to the volume which is being updated. It may + * be called arbitrary number of times until all the update data arriveis. This + * function returns %0 in case of success, number of bytes written during the + * last call if the whole volume update has been successfully finished, and a + * negative error code in case of failure. + */ +int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol, + const void __user *buf, int count) +{ + uint64_t tmp; + int lnum, offs, err = 0, len, to_write = count; + + dbg_msg("write %d of %lld bytes, %lld already passed", + count, vol->upd_bytes, vol->upd_received); + + if (ubi->ro_mode) + return -EROFS; + + tmp = vol->upd_received; + offs = do_div(tmp, vol->usable_leb_size); + lnum = tmp; + + if (vol->upd_received + count > vol->upd_bytes) + to_write = count = vol->upd_bytes - vol->upd_received; + + /* + * When updating volumes, we accumulate whole logical eraseblock of + * data and write it at once. + */ + if (offs != 0) { + /* + * This is a write to the middle of the logical eraseblock. We + * copy the data to our update buffer and wait for more data or + * flush it if the whole eraseblock is written or the update + * is finished. + */ + + len = vol->usable_leb_size - offs; + if (len > count) + len = count; + + err = copy_from_user(vol->upd_buf + offs, buf, len); + if (err) + return -EFAULT; + + if (offs + len == vol->usable_leb_size || + vol->upd_received + len == vol->upd_bytes) { + int flush_len = offs + len; + + /* + * OK, we gathered either the whole eraseblock or this + * is the last chunk, it's time to flush the buffer. + */ + ubi_assert(flush_len <= vol->usable_leb_size); + err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len, + vol->upd_ebs); + if (err) + return err; + } + + vol->upd_received += len; + count -= len; + buf += len; + lnum += 1; + } + + /* + * If we've got more to write, let's continue. At this point we know we + * are starting from the beginning of an eraseblock. + */ + while (count) { + if (count > vol->usable_leb_size) + len = vol->usable_leb_size; + else + len = count; + + err = copy_from_user(vol->upd_buf, buf, len); + if (err) + return -EFAULT; + + if (len == vol->usable_leb_size || + vol->upd_received + len == vol->upd_bytes) { + err = write_leb(ubi, vol, lnum, vol->upd_buf, + len, vol->upd_ebs); + if (err) + break; + } + + vol->upd_received += len; + count -= len; + lnum += 1; + buf += len; + } + + ubi_assert(vol->upd_received <= vol->upd_bytes); + if (vol->upd_received == vol->upd_bytes) { + /* The update is finished, clear the update marker */ + err = clear_update_marker(ubi, vol, vol->upd_bytes); + if (err) + return err; + err = ubi_wl_flush(ubi); + if (err == 0) { + vol->updating = 0; + err = to_write; + vfree(vol->upd_buf); + } + } + + return err; +} + +/** + * ubi_more_leb_change_data - accept more data for atomic LEB change. + * @vol: volume description object + * @buf: write data (user-space memory buffer) + * @count: how much bytes to write + * + * This function accepts more data to the volume which is being under the + * "atomic LEB change" operation. It may be called arbitrary number of times + * until all data arrives. This function returns %0 in case of success, number + * of bytes written during the last call if the whole "atomic LEB change" + * operation has been successfully finished, and a negative error code in case + * of failure. + */ +int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol, + const void __user *buf, int count) +{ + int err; + + dbg_msg("write %d of %lld bytes, %lld already passed", + count, vol->upd_bytes, vol->upd_received); + + if (ubi->ro_mode) + return -EROFS; + + if (vol->upd_received + count > vol->upd_bytes) + count = vol->upd_bytes - vol->upd_received; + + err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count); + if (err) + return -EFAULT; + + vol->upd_received += count; + + if (vol->upd_received == vol->upd_bytes) { + int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size); + + memset(vol->upd_buf + vol->upd_bytes, 0xFF, len - vol->upd_bytes); + len = ubi_calc_data_len(ubi, vol->upd_buf, len); + err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum, + vol->upd_buf, len, UBI_UNKNOWN); + if (err) + return err; + } + + ubi_assert(vol->upd_received <= vol->upd_bytes); + if (vol->upd_received == vol->upd_bytes) { + vol->changing_leb = 0; + err = count; + vfree(vol->upd_buf); + } + + return err; +} diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c new file mode 100644 index 0000000..a87a2f3 --- /dev/null +++ b/drivers/mtd/ubi/vmt.c @@ -0,0 +1,862 @@ +/* + * 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) + */ + +/* + * This file contains implementation of volume creation, deletion, updating and + * resizing. + */ + +#ifdef UBI_LINUX +#include <linux/err.h> +#include <asm/div64.h> +#endif + +#include <ubi_uboot.h> +#include "ubi.h" + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static void paranoid_check_volumes(struct ubi_device *ubi); +#else +#define paranoid_check_volumes(ubi) +#endif + +#ifdef UBI_LINUX +static ssize_t vol_attribute_show(struct device *dev, + struct device_attribute *attr, char *buf); + +/* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */ +static struct device_attribute attr_vol_reserved_ebs = + __ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute attr_vol_type = + __ATTR(type, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute attr_vol_name = + __ATTR(name, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute attr_vol_corrupted = + __ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute attr_vol_alignment = + __ATTR(alignment, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute attr_vol_usable_eb_size = + __ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute attr_vol_data_bytes = + __ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL); +static struct device_attribute attr_vol_upd_marker = + __ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL); + +/* + * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'. + * + * Consider a situation: + * A. process 1 opens a sysfs file related to volume Y, say + * /<sysfs>/class/ubi/ubiX_Y/reserved_ebs; + * B. process 2 removes volume Y; + * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file; + * + * In this situation, this function will return %-ENODEV because it will find + * out that the volume was removed from the @ubi->volumes array. + */ +static ssize_t vol_attribute_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int ret; + struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev); + struct ubi_device *ubi; + + ubi = ubi_get_device(vol->ubi->ubi_num); + if (!ubi) + return -ENODEV; + + spin_lock(&ubi->volumes_lock); + if (!ubi->volumes[vol->vol_id]) { + spin_unlock(&ubi->volumes_lock); + ubi_put_device(ubi); + return -ENODEV; + } + /* Take a reference to prevent volume removal */ + vol->ref_count += 1; + spin_unlock(&ubi->volumes_lock); + + if (attr == &attr_vol_reserved_ebs) + ret = sprintf(buf, "%d\n", vol->reserved_pebs); + else if (attr == &attr_vol_type) { + const char *tp; + + if (vol->vol_type == UBI_DYNAMIC_VOLUME) + tp = "dynamic"; + else + tp = "static"; + ret = sprintf(buf, "%s\n", tp); + } else if (attr == &attr_vol_name) + ret = sprintf(buf, "%s\n", vol->name); + else if (attr == &attr_vol_corrupted) + ret = sprintf(buf, "%d\n", vol->corrupted); + else if (attr == &attr_vol_alignment) + ret = sprintf(buf, "%d\n", vol->alignment); + else if (attr == &attr_vol_usable_eb_size) + ret = sprintf(buf, "%d\n", vol->usable_leb_size); + else if (attr == &attr_vol_data_bytes) + ret = sprintf(buf, "%lld\n", vol->used_bytes); + else if (attr == &attr_vol_upd_marker) + ret = sprintf(buf, "%d\n", vol->upd_marker); + else + /* This must be a bug */ + ret = -EINVAL; + + /* We've done the operation, drop volume and UBI device references */ + spin_lock(&ubi->volumes_lock); + vol->ref_count -= 1; + ubi_assert(vol->ref_count >= 0); + spin_unlock(&ubi->volumes_lock); + ubi_put_device(ubi); + return ret; +} +#endif + +/* Release method for volume devices */ +static void vol_release(struct device *dev) +{ + struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev); + + kfree(vol); +} + +#ifdef UBI_LINUX +/** + * volume_sysfs_init - initialize sysfs for new volume. + * @ubi: UBI device description object + * @vol: volume description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + * + * Note, this function does not free allocated resources in case of failure - + * the caller does it. This is because this would cause release() here and the + * caller would oops. + */ +static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol) +{ + int err; + + err = device_create_file(&vol->dev, &attr_vol_reserved_ebs); + if (err) + return err; + err = device_create_file(&vol->dev, &attr_vol_type); + if (err) + return err; + err = device_create_file(&vol->dev, &attr_vol_name); + if (err) + return err; + err = device_create_file(&vol->dev, &attr_vol_corrupted); + if (err) + return err; + err = device_create_file(&vol->dev, &attr_vol_alignment); + if (err) + return err; + err = device_create_file(&vol->dev, &attr_vol_usable_eb_size); + if (err) + return err; + err = device_create_file(&vol->dev, &attr_vol_data_bytes); + if (err) + return err; + err = device_create_file(&vol->dev, &attr_vol_upd_marker); + return err; +} + +/** + * volume_sysfs_close - close sysfs for a volume. + * @vol: volume description object + */ +static void volume_sysfs_close(struct ubi_volume *vol) +{ + device_remove_file(&vol->dev, &attr_vol_upd_marker); + device_remove_file(&vol->dev, &attr_vol_data_bytes); + device_remove_file(&vol->dev, &attr_vol_usable_eb_size); + device_remove_file(&vol->dev, &attr_vol_alignment); + device_remove_file(&vol->dev, &attr_vol_corrupted); + device_remove_file(&vol->dev, &attr_vol_name); + device_remove_file(&vol->dev, &attr_vol_type); + device_remove_file(&vol->dev, &attr_vol_reserved_ebs); + device_unregister(&vol->dev); +} +#endif + +/** + * ubi_create_volume - create volume. + * @ubi: UBI device description object + * @req: volume creation request + * + * This function creates volume described by @req. If @req->vol_id id + * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume + * and saves it in @req->vol_id. Returns zero in case of success and a negative + * error code in case of failure. Note, the caller has to have the + * @ubi->volumes_mutex locked. + */ +int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) +{ + int i, err, vol_id = req->vol_id, dont_free = 0; + struct ubi_volume *vol; + struct ubi_vtbl_record vtbl_rec; + uint64_t bytes; + dev_t dev; + + if (ubi->ro_mode) + return -EROFS; + + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + spin_lock(&ubi->volumes_lock); + if (vol_id == UBI_VOL_NUM_AUTO) { + /* Find unused volume ID */ + dbg_msg("search for vacant volume ID"); + for (i = 0; i < ubi->vtbl_slots; i++) + if (!ubi->volumes[i]) { + vol_id = i; + break; + } + + if (vol_id == UBI_VOL_NUM_AUTO) { + dbg_err("out of volume IDs"); + err = -ENFILE; + goto out_unlock; + } + req->vol_id = vol_id; + } + + dbg_msg("volume ID %d, %llu bytes, type %d, name %s", + vol_id, (unsigned long long)req->bytes, + (int)req->vol_type, req->name); + + /* Ensure that this volume does not exist */ + err = -EEXIST; + if (ubi->volumes[vol_id]) { + dbg_err("volume %d already exists", vol_id); + goto out_unlock; + } + + /* Ensure that the name is unique */ + for (i = 0; i < ubi->vtbl_slots; i++) + if (ubi->volumes[i] && + ubi->volumes[i]->name_len == req->name_len && + !strcmp(ubi->volumes[i]->name, req->name)) { + dbg_err("volume \"%s\" exists (ID %d)", req->name, i); + goto out_unlock; + } + + /* Calculate how many eraseblocks are requested */ + vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment; + bytes = req->bytes; + if (do_div(bytes, vol->usable_leb_size)) + vol->reserved_pebs = 1; + vol->reserved_pebs += bytes; + + /* Reserve physical eraseblocks */ + if (vol->reserved_pebs > ubi->avail_pebs) { + dbg_err("not enough PEBs, only %d available", ubi->avail_pebs); + err = -ENOSPC; + goto out_unlock; + } + ubi->avail_pebs -= vol->reserved_pebs; + ubi->rsvd_pebs += vol->reserved_pebs; + spin_unlock(&ubi->volumes_lock); + + vol->vol_id = vol_id; + vol->alignment = req->alignment; + vol->data_pad = ubi->leb_size % vol->alignment; + vol->vol_type = req->vol_type; + vol->name_len = req->name_len; + memcpy(vol->name, req->name, vol->name_len + 1); + vol->ubi = ubi; + + /* + * Finish all pending erases because there may be some LEBs belonging + * to the same volume ID. + */ + err = ubi_wl_flush(ubi); + if (err) + goto out_acc; + + vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL); + if (!vol->eba_tbl) { + err = -ENOMEM; + goto out_acc; + } + + for (i = 0; i < vol->reserved_pebs; i++) + vol->eba_tbl[i] = UBI_LEB_UNMAPPED; + + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->usable_leb_size; + vol->used_bytes = + (long long)vol->used_ebs * vol->usable_leb_size; + } else { + bytes = vol->used_bytes; + vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size); + vol->used_ebs = bytes; + if (vol->last_eb_bytes) + vol->used_ebs += 1; + else + vol->last_eb_bytes = vol->usable_leb_size; + } + + /* Register character device for the volume */ + cdev_init(&vol->cdev, &ubi_vol_cdev_operations); + vol->cdev.owner = THIS_MODULE; + dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1); + err = cdev_add(&vol->cdev, dev, 1); + if (err) { + ubi_err("cannot add character device"); + goto out_mapping; + } + + err = ubi_create_gluebi(ubi, vol); + if (err) + goto out_cdev; + + vol->dev.release = vol_release; + vol->dev.parent = &ubi->dev; + vol->dev.devt = dev; + vol->dev.class = ubi_class; + + sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id); + err = device_register(&vol->dev); + if (err) { + ubi_err("cannot register device"); + goto out_gluebi; + } + + err = volume_sysfs_init(ubi, vol); + if (err) + goto out_sysfs; + + /* Fill volume table record */ + memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record)); + vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs); + vtbl_rec.alignment = cpu_to_be32(vol->alignment); + vtbl_rec.data_pad = cpu_to_be32(vol->data_pad); + vtbl_rec.name_len = cpu_to_be16(vol->name_len); + if (vol->vol_type == UBI_DYNAMIC_VOLUME) + vtbl_rec.vol_type = UBI_VID_DYNAMIC; + else + vtbl_rec.vol_type = UBI_VID_STATIC; + memcpy(vtbl_rec.name, vol->name, vol->name_len + 1); + + err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec); + if (err) + goto out_sysfs; + + spin_lock(&ubi->volumes_lock); + ubi->volumes[vol_id] = vol; + ubi->vol_count += 1; + spin_unlock(&ubi->volumes_lock); + + paranoid_check_volumes(ubi); + return 0; + +out_sysfs: + /* + * We have registered our device, we should not free the volume* + * description object in this function in case of an error - it is + * freed by the release function. + * + * Get device reference to prevent the release function from being + * called just after sysfs has been closed. + */ + dont_free = 1; + get_device(&vol->dev); + volume_sysfs_close(vol); +out_gluebi: + if (ubi_destroy_gluebi(vol)) + dbg_err("cannot destroy gluebi for volume %d:%d", + ubi->ubi_num, vol_id); +out_cdev: + cdev_del(&vol->cdev); +out_mapping: + kfree(vol->eba_tbl); +out_acc: + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs -= vol->reserved_pebs; + ubi->avail_pebs += vol->reserved_pebs; +out_unlock: + spin_unlock(&ubi->volumes_lock); + if (dont_free) + put_device(&vol->dev); + else + kfree(vol); + ubi_err("cannot create volume %d, error %d", vol_id, err); + return err; +} + +/** + * ubi_remove_volume - remove volume. + * @desc: volume descriptor + * + * This function removes volume described by @desc. The volume has to be opened + * in "exclusive" mode. Returns zero in case of success and a negative error + * code in case of failure. The caller has to have the @ubi->volumes_mutex + * locked. + */ +int ubi_remove_volume(struct ubi_volume_desc *desc) +{ + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs; + + dbg_msg("remove UBI volume %d", vol_id); + ubi_assert(desc->mode == UBI_EXCLUSIVE); + ubi_assert(vol == ubi->volumes[vol_id]); + + if (ubi->ro_mode) + return -EROFS; + + spin_lock(&ubi->volumes_lock); + if (vol->ref_count > 1) { + /* + * The volume is busy, probably someone is reading one of its + * sysfs files. + */ + err = -EBUSY; + goto out_unlock; + } + ubi->volumes[vol_id] = NULL; + spin_unlock(&ubi->volumes_lock); + + err = ubi_destroy_gluebi(vol); + if (err) + goto out_err; + + err = ubi_change_vtbl_record(ubi, vol_id, NULL); + if (err) + goto out_err; + + for (i = 0; i < vol->reserved_pebs; i++) { + err = ubi_eba_unmap_leb(ubi, vol, i); + if (err) + goto out_err; + } + + kfree(vol->eba_tbl); + vol->eba_tbl = NULL; + cdev_del(&vol->cdev); + volume_sysfs_close(vol); + + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs -= reserved_pebs; + ubi->avail_pebs += reserved_pebs; + i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs; + if (i > 0) { + i = ubi->avail_pebs >= i ? i : ubi->avail_pebs; + ubi->avail_pebs -= i; + ubi->rsvd_pebs += i; + ubi->beb_rsvd_pebs += i; + if (i > 0) + ubi_msg("reserve more %d PEBs", i); + } + ubi->vol_count -= 1; + spin_unlock(&ubi->volumes_lock); + + paranoid_check_volumes(ubi); + return 0; + +out_err: + ubi_err("cannot remove volume %d, error %d", vol_id, err); + spin_lock(&ubi->volumes_lock); + ubi->volumes[vol_id] = vol; +out_unlock: + spin_unlock(&ubi->volumes_lock); + return err; +} + +/** + * ubi_resize_volume - re-size volume. + * @desc: volume descriptor + * @reserved_pebs: new size in physical eraseblocks + * + * This function re-sizes the volume and returns zero in case of success, and a + * negative error code in case of failure. The caller has to have the + * @ubi->volumes_mutex locked. + */ +int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) +{ + int i, err, pebs, *new_mapping; + struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; + struct ubi_vtbl_record vtbl_rec; + int vol_id = vol->vol_id; + + if (ubi->ro_mode) + return -EROFS; + + dbg_msg("re-size volume %d to from %d to %d PEBs", + vol_id, vol->reserved_pebs, reserved_pebs); + + if (vol->vol_type == UBI_STATIC_VOLUME && + reserved_pebs < vol->used_ebs) { + dbg_err("too small size %d, %d LEBs contain data", + reserved_pebs, vol->used_ebs); + return -EINVAL; + } + + /* If the size is the same, we have nothing to do */ + if (reserved_pebs == vol->reserved_pebs) + return 0; + + new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL); + if (!new_mapping) + return -ENOMEM; + + for (i = 0; i < reserved_pebs; i++) + new_mapping[i] = UBI_LEB_UNMAPPED; + + spin_lock(&ubi->volumes_lock); + if (vol->ref_count > 1) { + spin_unlock(&ubi->volumes_lock); + err = -EBUSY; + goto out_free; + } + spin_unlock(&ubi->volumes_lock); + + /* Reserve physical eraseblocks */ + pebs = reserved_pebs - vol->reserved_pebs; + if (pebs > 0) { + spin_lock(&ubi->volumes_lock); + if (pebs > ubi->avail_pebs) { + dbg_err("not enough PEBs: requested %d, available %d", + pebs, ubi->avail_pebs); + spin_unlock(&ubi->volumes_lock); + err = -ENOSPC; + goto out_free; + } + ubi->avail_pebs -= pebs; + ubi->rsvd_pebs += pebs; + for (i = 0; i < vol->reserved_pebs; i++) + new_mapping[i] = vol->eba_tbl[i]; + kfree(vol->eba_tbl); + vol->eba_tbl = new_mapping; + spin_unlock(&ubi->volumes_lock); + } + + /* Change volume table record */ + memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record)); + vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs); + err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec); + if (err) + goto out_acc; + + if (pebs < 0) { + for (i = 0; i < -pebs; i++) { + err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i); + if (err) + goto out_acc; + } + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs += pebs; + ubi->avail_pebs -= pebs; + pebs = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs; + if (pebs > 0) { + pebs = ubi->avail_pebs >= pebs ? pebs : ubi->avail_pebs; + ubi->avail_pebs -= pebs; + ubi->rsvd_pebs += pebs; + ubi->beb_rsvd_pebs += pebs; + if (pebs > 0) + ubi_msg("reserve more %d PEBs", pebs); + } + for (i = 0; i < reserved_pebs; i++) + new_mapping[i] = vol->eba_tbl[i]; + kfree(vol->eba_tbl); + vol->eba_tbl = new_mapping; + spin_unlock(&ubi->volumes_lock); + } + + vol->reserved_pebs = reserved_pebs; + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + vol->used_ebs = reserved_pebs; + vol->last_eb_bytes = vol->usable_leb_size; + vol->used_bytes = + (long long)vol->used_ebs * vol->usable_leb_size; + } + + paranoid_check_volumes(ubi); + return 0; + +out_acc: + if (pebs > 0) { + spin_lock(&ubi->volumes_lock); + ubi->rsvd_pebs -= pebs; + ubi->avail_pebs += pebs; + spin_unlock(&ubi->volumes_lock); + } +out_free: + kfree(new_mapping); + return err; +} + +/** + * ubi_add_volume - add volume. + * @ubi: UBI device description object + * @vol: volume description object + * + * This function adds an existing volume and initializes all its data + * structures. Returns zero in case of success and a negative error code in + * case of failure. + */ +int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol) +{ + int err, vol_id = vol->vol_id; + dev_t dev; + + dbg_msg("add volume %d", vol_id); + ubi_dbg_dump_vol_info(vol); + + /* Register character device for the volume */ + cdev_init(&vol->cdev, &ubi_vol_cdev_operations); + vol->cdev.owner = THIS_MODULE; + dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1); + err = cdev_add(&vol->cdev, dev, 1); + if (err) { + ubi_err("cannot add character device for volume %d, error %d", + vol_id, err); + return err; + } + + err = ubi_create_gluebi(ubi, vol); + if (err) + goto out_cdev; + + vol->dev.release = vol_release; + vol->dev.parent = &ubi->dev; + vol->dev.devt = dev; + vol->dev.class = ubi_class; + sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id); + err = device_register(&vol->dev); + if (err) + goto out_gluebi; + + err = volume_sysfs_init(ubi, vol); + if (err) { + cdev_del(&vol->cdev); + err = ubi_destroy_gluebi(vol); + volume_sysfs_close(vol); + return err; + } + + paranoid_check_volumes(ubi); + return 0; + +out_gluebi: + err = ubi_destroy_gluebi(vol); +out_cdev: + cdev_del(&vol->cdev); + return err; +} + +/** + * ubi_free_volume - free volume. + * @ubi: UBI device description object + * @vol: volume description object + * + * This function frees all resources for volume @vol but does not remove it. + * Used only when the UBI device is detached. + */ +void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol) +{ + int err; + + dbg_msg("free volume %d", vol->vol_id); + + ubi->volumes[vol->vol_id] = NULL; + err = ubi_destroy_gluebi(vol); + cdev_del(&vol->cdev); + volume_sysfs_close(vol); +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_check_volume - check volume information. + * @ubi: UBI device description object + * @vol_id: volume ID + */ +static void paranoid_check_volume(struct ubi_device *ubi, int vol_id) +{ + int idx = vol_id2idx(ubi, vol_id); + int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker; + const struct ubi_volume *vol; + long long n; + const char *name; + + spin_lock(&ubi->volumes_lock); + reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs); + vol = ubi->volumes[idx]; + + if (!vol) { + if (reserved_pebs) { + ubi_err("no volume info, but volume exists"); + goto fail; + } + spin_unlock(&ubi->volumes_lock); + return; + } + + if (vol->exclusive) { + /* + * The volume may be being created at the moment, do not check + * it (e.g., it may be in the middle of ubi_create_volume(). + */ + spin_unlock(&ubi->volumes_lock); + return; + } + + if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 || + vol->name_len < 0) { + ubi_err("negative values"); + goto fail; + } + if (vol->alignment > ubi->leb_size || vol->alignment == 0) { + ubi_err("bad alignment"); + goto fail; + } + + n = vol->alignment & (ubi->min_io_size - 1); + if (vol->alignment != 1 && n) { + ubi_err("alignment is not multiple of min I/O unit"); + goto fail; + } + + n = ubi->leb_size % vol->alignment; + if (vol->data_pad != n) { + ubi_err("bad data_pad, has to be %lld", n); + goto fail; + } + + if (vol->vol_type != UBI_DYNAMIC_VOLUME && + vol->vol_type != UBI_STATIC_VOLUME) { + ubi_err("bad vol_type"); + goto fail; + } + + if (vol->upd_marker && vol->corrupted) { + dbg_err("update marker and corrupted simultaneously"); + goto fail; + } + + if (vol->reserved_pebs > ubi->good_peb_count) { + ubi_err("too large reserved_pebs"); + goto fail; + } + + n = ubi->leb_size - vol->data_pad; + if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) { + ubi_err("bad usable_leb_size, has to be %lld", n); + goto fail; + } + + if (vol->name_len > UBI_VOL_NAME_MAX) { + ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX); + goto fail; + } + + if (!vol->name) { + ubi_err("NULL volume name"); + goto fail; + } + + n = strnlen(vol->name, vol->name_len + 1); + if (n != vol->name_len) { + ubi_err("bad name_len %lld", n); + goto fail; + } + + n = (long long)vol->used_ebs * vol->usable_leb_size; + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + if (vol->corrupted) { + ubi_err("corrupted dynamic volume"); + goto fail; + } + if (vol->used_ebs != vol->reserved_pebs) { + ubi_err("bad used_ebs"); + goto fail; + } + if (vol->last_eb_bytes != vol->usable_leb_size) { + ubi_err("bad last_eb_bytes"); + goto fail; + } + if (vol->used_bytes != n) { + ubi_err("bad used_bytes"); + goto fail; + } + } else { + if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) { + ubi_err("bad used_ebs"); + goto fail; + } + if (vol->last_eb_bytes < 0 || + vol->last_eb_bytes > vol->usable_leb_size) { + ubi_err("bad last_eb_bytes"); + goto fail; + } + if (vol->used_bytes < 0 || vol->used_bytes > n || + vol->used_bytes < n - vol->usable_leb_size) { + ubi_err("bad used_bytes"); + goto fail; + } + } + + alignment = be32_to_cpu(ubi->vtbl[vol_id].alignment); + data_pad = be32_to_cpu(ubi->vtbl[vol_id].data_pad); + name_len = be16_to_cpu(ubi->vtbl[vol_id].name_len); + upd_marker = ubi->vtbl[vol_id].upd_marker; + name = &ubi->vtbl[vol_id].name[0]; + if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC) + vol_type = UBI_DYNAMIC_VOLUME; + else + vol_type = UBI_STATIC_VOLUME; + + if (alignment != vol->alignment || data_pad != vol->data_pad || + upd_marker != vol->upd_marker || vol_type != vol->vol_type || + name_len!= vol->name_len || strncmp(name, vol->name, name_len)) { + ubi_err("volume info is different"); + goto fail; + } + + spin_unlock(&ubi->volumes_lock); + return; + +fail: + ubi_err("paranoid check failed for volume %d", vol_id); + ubi_dbg_dump_vol_info(vol); + ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id); + spin_unlock(&ubi->volumes_lock); + BUG(); +} + +/** + * paranoid_check_volumes - check information about all volumes. + * @ubi: UBI device description object + */ +static void paranoid_check_volumes(struct ubi_device *ubi) +{ + int i; + + for (i = 0; i < ubi->vtbl_slots; i++) + paranoid_check_volume(ubi, i); +} +#endif diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c new file mode 100644 index 0000000..9264ac6 --- /dev/null +++ b/drivers/mtd/ubi/vtbl.c @@ -0,0 +1,837 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2006, 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file includes volume table manipulation code. The volume table is an + * on-flash table containing volume meta-data like name, number of reserved + * physical eraseblocks, type, etc. The volume table is stored in the so-called + * "layout volume". + * + * The layout volume is an internal volume which is organized as follows. It + * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical + * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each + * other. This redundancy guarantees robustness to unclean reboots. The volume + * table is basically an array of volume table records. Each record contains + * full information about the volume and protected by a CRC checksum. + * + * The volume table is changed, it is first changed in RAM. Then LEB 0 is + * erased, and the updated volume table is written back to LEB 0. Then same for + * LEB 1. This scheme guarantees recoverability from unclean reboots. + * + * In this UBI implementation the on-flash volume table does not contain any + * information about how many data static volumes contain. This information may + * be found from the scanning data. + * + * But it would still be beneficial to store this information in the volume + * table. For example, suppose we have a static volume X, and all its physical + * eraseblocks became bad for some reasons. Suppose we are attaching the + * corresponding MTD device, the scanning has found no logical eraseblocks + * corresponding to the volume X. According to the volume table volume X does + * exist. So we don't know whether it is just empty or all its physical + * eraseblocks went bad. So we cannot alarm the user about this corruption. + * + * The volume table also stores so-called "update marker", which is used for + * volume updates. Before updating the volume, the update marker is set, and + * after the update operation is finished, the update marker is cleared. So if + * the update operation was interrupted (e.g. by an unclean reboot) - the + * update marker is still there and we know that the volume's contents is + * damaged. + */ + +#ifdef UBI_LINUX +#include <linux/crc32.h> +#include <linux/err.h> +#include <asm/div64.h> +#endif + +#include <ubi_uboot.h> +#include "ubi.h" + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static void paranoid_vtbl_check(const struct ubi_device *ubi); +#else +#define paranoid_vtbl_check(ubi) +#endif + +/* Empty volume table record */ +static struct ubi_vtbl_record empty_vtbl_record; + +/** + * ubi_change_vtbl_record - change volume table record. + * @ubi: UBI device description object + * @idx: table index to change + * @vtbl_rec: new volume table record + * + * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty + * volume table record is written. The caller does not have to calculate CRC of + * the record as it is done by this function. Returns zero in case of success + * and a negative error code in case of failure. + */ +int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, + struct ubi_vtbl_record *vtbl_rec) +{ + int i, err; + uint32_t crc; + struct ubi_volume *layout_vol; + + ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); + layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; + + if (!vtbl_rec) + vtbl_rec = &empty_vtbl_record; + else { + crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); + vtbl_rec->crc = cpu_to_be32(crc); + } + + memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); + for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { + err = ubi_eba_unmap_leb(ubi, layout_vol, i); + if (err) + return err; + + err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0, + ubi->vtbl_size, UBI_LONGTERM); + if (err) + return err; + } + + paranoid_vtbl_check(ubi); + return 0; +} + +/** + * vtbl_check - check if volume table is not corrupted and contains sensible + * data. + * @ubi: UBI device description object + * @vtbl: volume table + * + * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, + * and %-EINVAL if it contains inconsistent data. + */ +static int vtbl_check(const struct ubi_device *ubi, + const struct ubi_vtbl_record *vtbl) +{ + int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; + int upd_marker, err; + uint32_t crc; + const char *name; + + for (i = 0; i < ubi->vtbl_slots; i++) { + cond_resched(); + + reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); + alignment = be32_to_cpu(vtbl[i].alignment); + data_pad = be32_to_cpu(vtbl[i].data_pad); + upd_marker = vtbl[i].upd_marker; + vol_type = vtbl[i].vol_type; + name_len = be16_to_cpu(vtbl[i].name_len); + name = (const char *) &vtbl[i].name[0]; + + crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); + if (be32_to_cpu(vtbl[i].crc) != crc) { + ubi_err("bad CRC at record %u: %#08x, not %#08x", + i, crc, be32_to_cpu(vtbl[i].crc)); + ubi_dbg_dump_vtbl_record(&vtbl[i], i); + return 1; + } + + if (reserved_pebs == 0) { + if (memcmp(&vtbl[i], &empty_vtbl_record, + UBI_VTBL_RECORD_SIZE)) { + err = 2; + goto bad; + } + continue; + } + + if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || + name_len < 0) { + err = 3; + goto bad; + } + + if (alignment > ubi->leb_size || alignment == 0) { + err = 4; + goto bad; + } + + n = alignment & (ubi->min_io_size - 1); + if (alignment != 1 && n) { + err = 5; + goto bad; + } + + n = ubi->leb_size % alignment; + if (data_pad != n) { + dbg_err("bad data_pad, has to be %d", n); + err = 6; + goto bad; + } + + if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { + err = 7; + goto bad; + } + + if (upd_marker != 0 && upd_marker != 1) { + err = 8; + goto bad; + } + + if (reserved_pebs > ubi->good_peb_count) { + dbg_err("too large reserved_pebs, good PEBs %d", + ubi->good_peb_count); + err = 9; + goto bad; + } + + if (name_len > UBI_VOL_NAME_MAX) { + err = 10; + goto bad; + } + + if (name[0] == '\0') { + err = 11; + goto bad; + } + + if (name_len != strnlen(name, name_len + 1)) { + err = 12; + goto bad; + } + } + + /* Checks that all names are unique */ + for (i = 0; i < ubi->vtbl_slots - 1; i++) { + for (n = i + 1; n < ubi->vtbl_slots; n++) { + int len1 = be16_to_cpu(vtbl[i].name_len); + int len2 = be16_to_cpu(vtbl[n].name_len); + + if (len1 > 0 && len1 == len2 && + !strncmp((char *)vtbl[i].name, (char *)vtbl[n].name, len1)) { + ubi_err("volumes %d and %d have the same name" + " \"%s\"", i, n, vtbl[i].name); + ubi_dbg_dump_vtbl_record(&vtbl[i], i); + ubi_dbg_dump_vtbl_record(&vtbl[n], n); + return -EINVAL; + } + } + } + + return 0; + +bad: + ubi_err("volume table check failed: record %d, error %d", i, err); + ubi_dbg_dump_vtbl_record(&vtbl[i], i); + return -EINVAL; +} + +/** + * create_vtbl - create a copy of volume table. + * @ubi: UBI device description object + * @si: scanning information + * @copy: number of the volume table copy + * @vtbl: contents of the volume table + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si, + int copy, void *vtbl) +{ + int err, tries = 0; + static struct ubi_vid_hdr *vid_hdr; + struct ubi_scan_volume *sv; + struct ubi_scan_leb *new_seb, *old_seb = NULL; + + ubi_msg("create volume table (copy #%d)", copy + 1); + + vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); + if (!vid_hdr) + return -ENOMEM; + + /* + * Check if there is a logical eraseblock which would have to contain + * this volume table copy was found during scanning. It has to be wiped + * out. + */ + sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID); + if (sv) + old_seb = ubi_scan_find_seb(sv, copy); + +retry: + new_seb = ubi_scan_get_free_peb(ubi, si); + if (IS_ERR(new_seb)) { + err = PTR_ERR(new_seb); + goto out_free; + } + + vid_hdr->vol_type = UBI_VID_DYNAMIC; + vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID); + vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; + vid_hdr->data_size = vid_hdr->used_ebs = + vid_hdr->data_pad = cpu_to_be32(0); + vid_hdr->lnum = cpu_to_be32(copy); + vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum); + vid_hdr->leb_ver = cpu_to_be32(old_seb ? old_seb->leb_ver + 1: 0); + + /* The EC header is already there, write the VID header */ + err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr); + if (err) + goto write_error; + + /* Write the layout volume contents */ + err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size); + if (err) + goto write_error; + + /* + * And add it to the scanning information. Don't delete the old + * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'. + */ + err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec, + vid_hdr, 0); + kfree(new_seb); + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + +write_error: + if (err == -EIO && ++tries <= 5) { + /* + * Probably this physical eraseblock went bad, try to pick + * another one. + */ + list_add_tail(&new_seb->u.list, &si->corr); + goto retry; + } + kfree(new_seb); +out_free: + ubi_free_vid_hdr(ubi, vid_hdr); + return err; + +} + +/** + * process_lvol - process the layout volume. + * @ubi: UBI device description object + * @si: scanning information + * @sv: layout volume scanning information + * + * This function is responsible for reading the layout volume, ensuring it is + * not corrupted, and recovering from corruptions if needed. Returns volume + * table in case of success and a negative error code in case of failure. + */ +static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi, + struct ubi_scan_info *si, + struct ubi_scan_volume *sv) +{ + int err; + struct rb_node *rb; + struct ubi_scan_leb *seb; + struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; + int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; + + /* + * UBI goes through the following steps when it changes the layout + * volume: + * a. erase LEB 0; + * b. write new data to LEB 0; + * c. erase LEB 1; + * d. write new data to LEB 1. + * + * Before the change, both LEBs contain the same data. + * + * Due to unclean reboots, the contents of LEB 0 may be lost, but there + * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. + * Similarly, LEB 1 may be lost, but there should be LEB 0. And + * finally, unclean reboots may result in a situation when neither LEB + * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB + * 0 contains more recent information. + * + * So the plan is to first check LEB 0. Then + * a. if LEB 0 is OK, it must be containing the most resent data; then + * we compare it with LEB 1, and if they are different, we copy LEB + * 0 to LEB 1; + * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 + * to LEB 0. + */ + + dbg_msg("check layout volume"); + + /* Read both LEB 0 and LEB 1 into memory */ + ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { + leb[seb->lnum] = vmalloc(ubi->vtbl_size); + if (!leb[seb->lnum]) { + err = -ENOMEM; + goto out_free; + } + memset(leb[seb->lnum], 0, ubi->vtbl_size); + + err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0, + ubi->vtbl_size); + if (err == UBI_IO_BITFLIPS || err == -EBADMSG) + /* + * Scrub the PEB later. Note, -EBADMSG indicates an + * uncorrectable ECC error, but we have our own CRC and + * the data will be checked later. If the data is OK, + * the PEB will be scrubbed (because we set + * seb->scrub). If the data is not OK, the contents of + * the PEB will be recovered from the second copy, and + * seb->scrub will be cleared in + * 'ubi_scan_add_used()'. + */ + seb->scrub = 1; + else if (err) + goto out_free; + } + + err = -EINVAL; + if (leb[0]) { + leb_corrupted[0] = vtbl_check(ubi, leb[0]); + if (leb_corrupted[0] < 0) + goto out_free; + } + + if (!leb_corrupted[0]) { + /* LEB 0 is OK */ + if (leb[1]) + leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size); + if (leb_corrupted[1]) { + ubi_warn("volume table copy #2 is corrupted"); + err = create_vtbl(ubi, si, 1, leb[0]); + if (err) + goto out_free; + ubi_msg("volume table was restored"); + } + + /* Both LEB 1 and LEB 2 are OK and consistent */ + vfree(leb[1]); + return leb[0]; + } else { + /* LEB 0 is corrupted or does not exist */ + if (leb[1]) { + leb_corrupted[1] = vtbl_check(ubi, leb[1]); + if (leb_corrupted[1] < 0) + goto out_free; + } + if (leb_corrupted[1]) { + /* Both LEB 0 and LEB 1 are corrupted */ + ubi_err("both volume tables are corrupted"); + goto out_free; + } + + ubi_warn("volume table copy #1 is corrupted"); + err = create_vtbl(ubi, si, 0, leb[1]); + if (err) + goto out_free; + ubi_msg("volume table was restored"); + + vfree(leb[0]); + return leb[1]; + } + +out_free: + vfree(leb[0]); + vfree(leb[1]); + return ERR_PTR(err); +} + +/** + * create_empty_lvol - create empty layout volume. + * @ubi: UBI device description object + * @si: scanning information + * + * This function returns volume table contents in case of success and a + * negative error code in case of failure. + */ +static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi, + struct ubi_scan_info *si) +{ + int i; + struct ubi_vtbl_record *vtbl; + + vtbl = vmalloc(ubi->vtbl_size); + if (!vtbl) + return ERR_PTR(-ENOMEM); + memset(vtbl, 0, ubi->vtbl_size); + + for (i = 0; i < ubi->vtbl_slots; i++) + memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); + + for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { + int err; + + err = create_vtbl(ubi, si, i, vtbl); + if (err) { + vfree(vtbl); + return ERR_PTR(err); + } + } + + return vtbl; +} + +/** + * init_volumes - initialize volume information for existing volumes. + * @ubi: UBI device description object + * @si: scanning information + * @vtbl: volume table + * + * This function allocates volume description objects for existing volumes. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si, + const struct ubi_vtbl_record *vtbl) +{ + int i, reserved_pebs = 0; + struct ubi_scan_volume *sv; + struct ubi_volume *vol; + + for (i = 0; i < ubi->vtbl_slots; i++) { + cond_resched(); + + if (be32_to_cpu(vtbl[i].reserved_pebs) == 0) + continue; /* Empty record */ + + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); + vol->alignment = be32_to_cpu(vtbl[i].alignment); + vol->data_pad = be32_to_cpu(vtbl[i].data_pad); + vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? + UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; + vol->name_len = be16_to_cpu(vtbl[i].name_len); + vol->usable_leb_size = ubi->leb_size - vol->data_pad; + memcpy(vol->name, vtbl[i].name, vol->name_len); + vol->name[vol->name_len] = '\0'; + vol->vol_id = i; + + if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) { + /* Auto re-size flag may be set only for one volume */ + if (ubi->autoresize_vol_id != -1) { + ubi_err("more then one auto-resize volume (%d " + "and %d)", ubi->autoresize_vol_id, i); + kfree(vol); + return -EINVAL; + } + + ubi->autoresize_vol_id = i; + } + + ubi_assert(!ubi->volumes[i]); + ubi->volumes[i] = vol; + ubi->vol_count += 1; + vol->ubi = ubi; + reserved_pebs += vol->reserved_pebs; + + /* + * In case of dynamic volume UBI knows nothing about how many + * data is stored there. So assume the whole volume is used. + */ + if (vol->vol_type == UBI_DYNAMIC_VOLUME) { + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->usable_leb_size; + vol->used_bytes = + (long long)vol->used_ebs * vol->usable_leb_size; + continue; + } + + /* Static volumes only */ + sv = ubi_scan_find_sv(si, i); + if (!sv) { + /* + * No eraseblocks belonging to this volume found. We + * don't actually know whether this static volume is + * completely corrupted or just contains no data. And + * we cannot know this as long as data size is not + * stored on flash. So we just assume the volume is + * empty. FIXME: this should be handled. + */ + continue; + } + + if (sv->leb_count != sv->used_ebs) { + /* + * We found a static volume which misses several + * eraseblocks. Treat it as corrupted. + */ + ubi_warn("static volume %d misses %d LEBs - corrupted", + sv->vol_id, sv->used_ebs - sv->leb_count); + vol->corrupted = 1; + continue; + } + + vol->used_ebs = sv->used_ebs; + vol->used_bytes = + (long long)(vol->used_ebs - 1) * vol->usable_leb_size; + vol->used_bytes += sv->last_data_size; + vol->last_eb_bytes = sv->last_data_size; + } + + /* And add the layout volume */ + vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); + if (!vol) + return -ENOMEM; + + vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; + vol->alignment = 1; + vol->vol_type = UBI_DYNAMIC_VOLUME; + vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; + memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); + vol->usable_leb_size = ubi->leb_size; + vol->used_ebs = vol->reserved_pebs; + vol->last_eb_bytes = vol->reserved_pebs; + vol->used_bytes = + (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); + vol->vol_id = UBI_LAYOUT_VOLUME_ID; + vol->ref_count = 1; + + ubi_assert(!ubi->volumes[i]); + ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; + reserved_pebs += vol->reserved_pebs; + ubi->vol_count += 1; + vol->ubi = ubi; + + if (reserved_pebs > ubi->avail_pebs) + ubi_err("not enough PEBs, required %d, available %d", + reserved_pebs, ubi->avail_pebs); + ubi->rsvd_pebs += reserved_pebs; + ubi->avail_pebs -= reserved_pebs; + + return 0; +} + +/** + * check_sv - check volume scanning information. + * @vol: UBI volume description object + * @sv: volume scanning information + * + * This function returns zero if the volume scanning information is consistent + * to the data read from the volume tabla, and %-EINVAL if not. + */ +static int check_sv(const struct ubi_volume *vol, + const struct ubi_scan_volume *sv) +{ + int err; + + if (sv->highest_lnum >= vol->reserved_pebs) { + err = 1; + goto bad; + } + if (sv->leb_count > vol->reserved_pebs) { + err = 2; + goto bad; + } + if (sv->vol_type != vol->vol_type) { + err = 3; + goto bad; + } + if (sv->used_ebs > vol->reserved_pebs) { + err = 4; + goto bad; + } + if (sv->data_pad != vol->data_pad) { + err = 5; + goto bad; + } + return 0; + +bad: + ubi_err("bad scanning information, error %d", err); + ubi_dbg_dump_sv(sv); + ubi_dbg_dump_vol_info(vol); + return -EINVAL; +} + +/** + * check_scanning_info - check that scanning information. + * @ubi: UBI device description object + * @si: scanning information + * + * Even though we protect on-flash data by CRC checksums, we still don't trust + * the media. This function ensures that scanning information is consistent to + * the information read from the volume table. Returns zero if the scanning + * information is OK and %-EINVAL if it is not. + */ +static int check_scanning_info(const struct ubi_device *ubi, + struct ubi_scan_info *si) +{ + int err, i; + struct ubi_scan_volume *sv; + struct ubi_volume *vol; + + if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { + ubi_err("scanning found %d volumes, maximum is %d + %d", + si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); + return -EINVAL; + } + + if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT && + si->highest_vol_id < UBI_INTERNAL_VOL_START) { + ubi_err("too large volume ID %d found by scanning", + si->highest_vol_id); + return -EINVAL; + } + + for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { + cond_resched(); + + sv = ubi_scan_find_sv(si, i); + vol = ubi->volumes[i]; + if (!vol) { + if (sv) + ubi_scan_rm_volume(si, sv); + continue; + } + + if (vol->reserved_pebs == 0) { + ubi_assert(i < ubi->vtbl_slots); + + if (!sv) + continue; + + /* + * During scanning we found a volume which does not + * exist according to the information in the volume + * table. This must have happened due to an unclean + * reboot while the volume was being removed. Discard + * these eraseblocks. + */ + ubi_msg("finish volume %d removal", sv->vol_id); + ubi_scan_rm_volume(si, sv); + } else if (sv) { + err = check_sv(vol, sv); + if (err) + return err; + } + } + + return 0; +} + +/** + * ubi_read_volume_table - read volume table. + * information. + * @ubi: UBI device description object + * @si: scanning information + * + * This function reads volume table, checks it, recover from errors if needed, + * or creates it if needed. Returns zero in case of success and a negative + * error code in case of failure. + */ +int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si) +{ + int i, err; + struct ubi_scan_volume *sv; + + empty_vtbl_record.crc = cpu_to_be32(0xf116c36b); + + /* + * The number of supported volumes is limited by the eraseblock size + * and by the UBI_MAX_VOLUMES constant. + */ + ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; + if (ubi->vtbl_slots > UBI_MAX_VOLUMES) + ubi->vtbl_slots = UBI_MAX_VOLUMES; + + ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; + ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); + + sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID); + if (!sv) { + /* + * No logical eraseblocks belonging to the layout volume were + * found. This could mean that the flash is just empty. In + * this case we create empty layout volume. + * + * But if flash is not empty this must be a corruption or the + * MTD device just contains garbage. + */ + if (si->is_empty) { + ubi->vtbl = create_empty_lvol(ubi, si); + if (IS_ERR(ubi->vtbl)) + return PTR_ERR(ubi->vtbl); + } else { + ubi_err("the layout volume was not found"); + return -EINVAL; + } + } else { + if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) { + /* This must not happen with proper UBI images */ + dbg_err("too many LEBs (%d) in layout volume", + sv->leb_count); + return -EINVAL; + } + + ubi->vtbl = process_lvol(ubi, si, sv); + if (IS_ERR(ubi->vtbl)) + return PTR_ERR(ubi->vtbl); + } + + ubi->avail_pebs = ubi->good_peb_count; + + /* + * The layout volume is OK, initialize the corresponding in-RAM data + * structures. + */ + err = init_volumes(ubi, si, ubi->vtbl); + if (err) + goto out_free; + + /* + * Get sure that the scanning information is consistent to the + * information stored in the volume table. + */ + err = check_scanning_info(ubi, si); + if (err) + goto out_free; + + return 0; + +out_free: + vfree(ubi->vtbl); + for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) + if (ubi->volumes[i]) { + kfree(ubi->volumes[i]); + ubi->volumes[i] = NULL; + } + return err; +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_vtbl_check - check volume table. + * @ubi: UBI device description object + */ +static void paranoid_vtbl_check(const struct ubi_device *ubi) +{ + if (vtbl_check(ubi, ubi->vtbl)) { + ubi_err("paranoid check failed"); + BUG(); + } +} + +#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c new file mode 100644 index 0000000..2f9a5e3 --- /dev/null +++ b/drivers/mtd/ubi/wl.c @@ -0,0 +1,1670 @@ +/* + * 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 + * + * Authors: Artem Bityutskiy (Битюцкий Артём), Thomas Gleixner + */ + +/* + * UBI wear-leveling unit. + * + * This unit is responsible for wear-leveling. It works in terms of physical + * eraseblocks and erase counters and knows nothing about logical eraseblocks, + * volumes, etc. From this unit's perspective all physical eraseblocks are of + * two types - used and free. Used physical eraseblocks are those that were + * "get" by the 'ubi_wl_get_peb()' function, and free physical eraseblocks are + * those that were put by the 'ubi_wl_put_peb()' function. + * + * Physical eraseblocks returned by 'ubi_wl_get_peb()' have only erase counter + * header. The rest of the physical eraseblock contains only 0xFF bytes. + * + * When physical eraseblocks are returned to the WL unit by means of the + * 'ubi_wl_put_peb()' function, they are scheduled for erasure. The erasure is + * done asynchronously in context of the per-UBI device background thread, + * which is also managed by the WL unit. + * + * The wear-leveling is ensured by means of moving the contents of used + * physical eraseblocks with low erase counter to free physical eraseblocks + * with high erase counter. + * + * The 'ubi_wl_get_peb()' function accepts data type hints which help to pick + * an "optimal" physical eraseblock. For example, when it is known that the + * physical eraseblock will be "put" soon because it contains short-term data, + * the WL unit may pick a free physical eraseblock with low erase counter, and + * so forth. + * + * If the WL unit fails to erase a physical eraseblock, it marks it as bad. + * + * This unit is also responsible for scrubbing. If a bit-flip is detected in a + * physical eraseblock, it has to be moved. Technically this is the same as + * moving it for wear-leveling reasons. + * + * As it was said, for the UBI unit all physical eraseblocks are either "free" + * or "used". Free eraseblock are kept in the @wl->free RB-tree, while used + * eraseblocks are kept in a set of different RB-trees: @wl->used, + * @wl->prot.pnum, @wl->prot.aec, and @wl->scrub. + * + * Note, in this implementation, we keep a small in-RAM object for each physical + * eraseblock. This is surely not a scalable solution. But it appears to be good + * enough for moderately large flashes and it is simple. In future, one may + * re-work this unit and make it more scalable. + * + * At the moment this unit does not utilize the sequence number, which was + * introduced relatively recently. But it would be wise to do this because the + * sequence number of a logical eraseblock characterizes how old is it. For + * example, when we move a PEB with low erase counter, and we need to pick the + * target PEB, we pick a PEB with the highest EC if our PEB is "old" and we + * pick target PEB with an average EC if our PEB is not very "old". This is a + * room for future re-works of the WL unit. + * + * FIXME: looks too complex, should be simplified (later). + */ + +#ifdef UBI_LINUX +#include <linux/slab.h> +#include <linux/crc32.h> +#include <linux/freezer.h> +#include <linux/kthread.h> +#endif + +#include <ubi_uboot.h> +#include "ubi.h" + +/* Number of physical eraseblocks reserved for wear-leveling purposes */ +#define WL_RESERVED_PEBS 1 + +/* + * How many erase cycles are short term, unknown, and long term physical + * eraseblocks protected. + */ +#define ST_PROTECTION 16 +#define U_PROTECTION 10 +#define LT_PROTECTION 4 + +/* + * Maximum difference between two erase counters. If this threshold is + * exceeded, the WL unit starts moving data from used physical eraseblocks with + * low erase counter to free physical eraseblocks with high erase counter. + */ +#define UBI_WL_THRESHOLD CONFIG_MTD_UBI_WL_THRESHOLD + +/* + * When a physical eraseblock is moved, the WL unit has to pick the target + * physical eraseblock to move to. The simplest way would be just to pick the + * one with the highest erase counter. But in certain workloads this could lead + * to an unlimited wear of one or few physical eraseblock. Indeed, imagine a + * situation when the picked physical eraseblock is constantly erased after the + * data is written to it. So, we have a constant which limits the highest erase + * counter of the free physical eraseblock to pick. Namely, the WL unit does + * not pick eraseblocks with erase counter greater then the lowest erase + * counter plus %WL_FREE_MAX_DIFF. + */ +#define WL_FREE_MAX_DIFF (2*UBI_WL_THRESHOLD) + +/* + * Maximum number of consecutive background thread failures which is enough to + * switch to read-only mode. + */ +#define WL_MAX_FAILURES 32 + +/** + * struct ubi_wl_prot_entry - PEB protection entry. + * @rb_pnum: link in the @wl->prot.pnum RB-tree + * @rb_aec: link in the @wl->prot.aec RB-tree + * @abs_ec: the absolute erase counter value when the protection ends + * @e: the wear-leveling entry of the physical eraseblock under protection + * + * When the WL unit returns a physical eraseblock, the physical eraseblock is + * protected from being moved for some "time". For this reason, the physical + * eraseblock is not directly moved from the @wl->free tree to the @wl->used + * tree. There is one more tree in between where this physical eraseblock is + * temporarily stored (@wl->prot). + * + * All this protection stuff is needed because: + * o we don't want to move physical eraseblocks just after we have given them + * to the user; instead, we first want to let users fill them up with data; + * + * o there is a chance that the user will put the physical eraseblock very + * soon, so it makes sense not to move it for some time, but wait; this is + * especially important in case of "short term" physical eraseblocks. + * + * Physical eraseblocks stay protected only for limited time. But the "time" is + * measured in erase cycles in this case. This is implemented with help of the + * absolute erase counter (@wl->abs_ec). When it reaches certain value, the + * physical eraseblocks are moved from the protection trees (@wl->prot.*) to + * the @wl->used tree. + * + * Protected physical eraseblocks are searched by physical eraseblock number + * (when they are put) and by the absolute erase counter (to check if it is + * time to move them to the @wl->used tree). So there are actually 2 RB-trees + * storing the protected physical eraseblocks: @wl->prot.pnum and + * @wl->prot.aec. They are referred to as the "protection" trees. The + * first one is indexed by the physical eraseblock number. The second one is + * indexed by the absolute erase counter. Both trees store + * &struct ubi_wl_prot_entry objects. + * + * Each physical eraseblock has 2 main states: free and used. The former state + * corresponds to the @wl->free tree. The latter state is split up on several + * sub-states: + * o the WL movement is allowed (@wl->used tree); + * o the WL movement is temporarily prohibited (@wl->prot.pnum and + * @wl->prot.aec trees); + * o scrubbing is needed (@wl->scrub tree). + * + * Depending on the sub-state, wear-leveling entries of the used physical + * eraseblocks may be kept in one of those trees. + */ +struct ubi_wl_prot_entry { + struct rb_node rb_pnum; + struct rb_node rb_aec; + unsigned long long abs_ec; + struct ubi_wl_entry *e; +}; + +/** + * struct ubi_work - UBI work description data structure. + * @list: a link in the list of pending works + * @func: worker function + * @priv: private data of the worker function + * + * @e: physical eraseblock to erase + * @torture: if the physical eraseblock has to be tortured + * + * The @func pointer points to the worker function. If the @cancel argument is + * not zero, the worker has to free the resources and exit immediately. The + * worker has to return zero in case of success and a negative error code in + * case of failure. + */ +struct ubi_work { + struct list_head list; + int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel); + /* The below fields are only relevant to erasure works */ + struct ubi_wl_entry *e; + int torture; +}; + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec); +static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e, + struct rb_root *root); +#else +#define paranoid_check_ec(ubi, pnum, ec) 0 +#define paranoid_check_in_wl_tree(e, root) +#endif + +/** + * wl_tree_add - add a wear-leveling entry to a WL RB-tree. + * @e: the wear-leveling entry to add + * @root: the root of the tree + * + * Note, we use (erase counter, physical eraseblock number) pairs as keys in + * the @ubi->used and @ubi->free RB-trees. + */ +static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root) +{ + struct rb_node **p, *parent = NULL; + + p = &root->rb_node; + while (*p) { + struct ubi_wl_entry *e1; + + parent = *p; + e1 = rb_entry(parent, struct ubi_wl_entry, rb); + + if (e->ec < e1->ec) + p = &(*p)->rb_left; + else if (e->ec > e1->ec) + p = &(*p)->rb_right; + else { + ubi_assert(e->pnum != e1->pnum); + if (e->pnum < e1->pnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + } + + rb_link_node(&e->rb, parent, p); + rb_insert_color(&e->rb, root); +} + +/** + * do_work - do one pending work. + * @ubi: UBI device description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int do_work(struct ubi_device *ubi) +{ + int err; + struct ubi_work *wrk; + + cond_resched(); + + /* + * @ubi->work_sem is used to synchronize with the workers. Workers take + * it in read mode, so many of them may be doing works at a time. But + * the queue flush code has to be sure the whole queue of works is + * done, and it takes the mutex in write mode. + */ + down_read(&ubi->work_sem); + spin_lock(&ubi->wl_lock); + if (list_empty(&ubi->works)) { + spin_unlock(&ubi->wl_lock); + up_read(&ubi->work_sem); + return 0; + } + + wrk = list_entry(ubi->works.next, struct ubi_work, list); + list_del(&wrk->list); + ubi->works_count -= 1; + ubi_assert(ubi->works_count >= 0); + spin_unlock(&ubi->wl_lock); + + /* + * Call the worker function. Do not touch the work structure + * after this call as it will have been freed or reused by that + * time by the worker function. + */ + err = wrk->func(ubi, wrk, 0); + if (err) + ubi_err("work failed with error code %d", err); + up_read(&ubi->work_sem); + + return err; +} + +/** + * produce_free_peb - produce a free physical eraseblock. + * @ubi: UBI device description object + * + * This function tries to make a free PEB by means of synchronous execution of + * pending works. This may be needed if, for example the background thread is + * disabled. Returns zero in case of success and a negative error code in case + * of failure. + */ +static int produce_free_peb(struct ubi_device *ubi) +{ + int err; + + spin_lock(&ubi->wl_lock); + while (!ubi->free.rb_node) { + spin_unlock(&ubi->wl_lock); + + dbg_wl("do one work synchronously"); + err = do_work(ubi); + if (err) + return err; + + spin_lock(&ubi->wl_lock); + } + spin_unlock(&ubi->wl_lock); + + return 0; +} + +/** + * in_wl_tree - check if wear-leveling entry is present in a WL RB-tree. + * @e: the wear-leveling entry to check + * @root: the root of the tree + * + * This function returns non-zero if @e is in the @root RB-tree and zero if it + * is not. + */ +static int in_wl_tree(struct ubi_wl_entry *e, struct rb_root *root) +{ + struct rb_node *p; + + p = root->rb_node; + while (p) { + struct ubi_wl_entry *e1; + + e1 = rb_entry(p, struct ubi_wl_entry, rb); + + if (e->pnum == e1->pnum) { + ubi_assert(e == e1); + return 1; + } + + if (e->ec < e1->ec) + p = p->rb_left; + else if (e->ec > e1->ec) + p = p->rb_right; + else { + ubi_assert(e->pnum != e1->pnum); + if (e->pnum < e1->pnum) + p = p->rb_left; + else + p = p->rb_right; + } + } + + return 0; +} + +/** + * prot_tree_add - add physical eraseblock to protection trees. + * @ubi: UBI device description object + * @e: the physical eraseblock to add + * @pe: protection entry object to use + * @abs_ec: absolute erase counter value when this physical eraseblock has + * to be removed from the protection trees. + * + * @wl->lock has to be locked. + */ +static void prot_tree_add(struct ubi_device *ubi, struct ubi_wl_entry *e, + struct ubi_wl_prot_entry *pe, int abs_ec) +{ + struct rb_node **p, *parent = NULL; + struct ubi_wl_prot_entry *pe1; + + pe->e = e; + pe->abs_ec = ubi->abs_ec + abs_ec; + + p = &ubi->prot.pnum.rb_node; + while (*p) { + parent = *p; + pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_pnum); + + if (e->pnum < pe1->e->pnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + rb_link_node(&pe->rb_pnum, parent, p); + rb_insert_color(&pe->rb_pnum, &ubi->prot.pnum); + + p = &ubi->prot.aec.rb_node; + parent = NULL; + while (*p) { + parent = *p; + pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_aec); + + if (pe->abs_ec < pe1->abs_ec) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + rb_link_node(&pe->rb_aec, parent, p); + rb_insert_color(&pe->rb_aec, &ubi->prot.aec); +} + +/** + * find_wl_entry - find wear-leveling entry closest to certain erase counter. + * @root: the RB-tree where to look for + * @max: highest possible erase counter + * + * This function looks for a wear leveling entry with erase counter closest to + * @max and less then @max. + */ +static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int max) +{ + struct rb_node *p; + struct ubi_wl_entry *e; + + e = rb_entry(rb_first(root), struct ubi_wl_entry, rb); + max += e->ec; + + p = root->rb_node; + while (p) { + struct ubi_wl_entry *e1; + + e1 = rb_entry(p, struct ubi_wl_entry, rb); + if (e1->ec >= max) + p = p->rb_left; + else { + p = p->rb_right; + e = e1; + } + } + + return e; +} + +/** + * ubi_wl_get_peb - get a physical eraseblock. + * @ubi: UBI device description object + * @dtype: type of data which will be stored in this physical eraseblock + * + * This function returns a physical eraseblock in case of success and a + * negative error code in case of failure. Might sleep. + */ +int ubi_wl_get_peb(struct ubi_device *ubi, int dtype) +{ + int err, protect, medium_ec; + struct ubi_wl_entry *e, *first, *last; + struct ubi_wl_prot_entry *pe; + + ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM || + dtype == UBI_UNKNOWN); + + pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS); + if (!pe) + return -ENOMEM; + +retry: + spin_lock(&ubi->wl_lock); + if (!ubi->free.rb_node) { + if (ubi->works_count == 0) { + ubi_assert(list_empty(&ubi->works)); + ubi_err("no free eraseblocks"); + spin_unlock(&ubi->wl_lock); + kfree(pe); + return -ENOSPC; + } + spin_unlock(&ubi->wl_lock); + + err = produce_free_peb(ubi); + if (err < 0) { + kfree(pe); + return err; + } + goto retry; + } + + switch (dtype) { + case UBI_LONGTERM: + /* + * For long term data we pick a physical eraseblock + * with high erase counter. But the highest erase + * counter we can pick is bounded by the the lowest + * erase counter plus %WL_FREE_MAX_DIFF. + */ + e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + protect = LT_PROTECTION; + break; + case UBI_UNKNOWN: + /* + * For unknown data we pick a physical eraseblock with + * medium erase counter. But we by no means can pick a + * physical eraseblock with erase counter greater or + * equivalent than the lowest erase counter plus + * %WL_FREE_MAX_DIFF. + */ + first = rb_entry(rb_first(&ubi->free), + struct ubi_wl_entry, rb); + last = rb_entry(rb_last(&ubi->free), + struct ubi_wl_entry, rb); + + if (last->ec - first->ec < WL_FREE_MAX_DIFF) + e = rb_entry(ubi->free.rb_node, + struct ubi_wl_entry, rb); + else { + medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2; + e = find_wl_entry(&ubi->free, medium_ec); + } + protect = U_PROTECTION; + break; + case UBI_SHORTTERM: + /* + * For short term data we pick a physical eraseblock + * with the lowest erase counter as we expect it will + * be erased soon. + */ + e = rb_entry(rb_first(&ubi->free), + struct ubi_wl_entry, rb); + protect = ST_PROTECTION; + break; + default: + protect = 0; + e = NULL; + BUG(); + } + + /* + * Move the physical eraseblock to the protection trees where it will + * be protected from being moved for some time. + */ + paranoid_check_in_wl_tree(e, &ubi->free); + rb_erase(&e->rb, &ubi->free); + prot_tree_add(ubi, e, pe, protect); + + dbg_wl("PEB %d EC %d, protection %d", e->pnum, e->ec, protect); + spin_unlock(&ubi->wl_lock); + + return e->pnum; +} + +/** + * prot_tree_del - remove a physical eraseblock from the protection trees + * @ubi: UBI device description object + * @pnum: the physical eraseblock to remove + * + * This function returns PEB @pnum from the protection trees and returns zero + * in case of success and %-ENODEV if the PEB was not found in the protection + * trees. + */ +static int prot_tree_del(struct ubi_device *ubi, int pnum) +{ + struct rb_node *p; + struct ubi_wl_prot_entry *pe = NULL; + + p = ubi->prot.pnum.rb_node; + while (p) { + + pe = rb_entry(p, struct ubi_wl_prot_entry, rb_pnum); + + if (pnum == pe->e->pnum) + goto found; + + if (pnum < pe->e->pnum) + p = p->rb_left; + else + p = p->rb_right; + } + + return -ENODEV; + +found: + ubi_assert(pe->e->pnum == pnum); + rb_erase(&pe->rb_aec, &ubi->prot.aec); + rb_erase(&pe->rb_pnum, &ubi->prot.pnum); + kfree(pe); + return 0; +} + +/** + * sync_erase - synchronously erase a physical eraseblock. + * @ubi: UBI device description object + * @e: the the physical eraseblock to erase + * @torture: if the physical eraseblock has to be tortured + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture) +{ + int err; + struct ubi_ec_hdr *ec_hdr; + unsigned long long ec = e->ec; + + dbg_wl("erase PEB %d, old EC %llu", e->pnum, ec); + + err = paranoid_check_ec(ubi, e->pnum, e->ec); + if (err > 0) + return -EINVAL; + + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS); + if (!ec_hdr) + return -ENOMEM; + + err = ubi_io_sync_erase(ubi, e->pnum, torture); + if (err < 0) + goto out_free; + + ec += err; + if (ec > UBI_MAX_ERASECOUNTER) { + /* + * Erase counter overflow. Upgrade UBI and use 64-bit + * erase counters internally. + */ + ubi_err("erase counter overflow at PEB %d, EC %llu", + e->pnum, ec); + err = -EINVAL; + goto out_free; + } + + dbg_wl("erased PEB %d, new EC %llu", e->pnum, ec); + + ec_hdr->ec = cpu_to_be64(ec); + + err = ubi_io_write_ec_hdr(ubi, e->pnum, ec_hdr); + if (err) + goto out_free; + + e->ec = ec; + spin_lock(&ubi->wl_lock); + if (e->ec > ubi->max_ec) + ubi->max_ec = e->ec; + spin_unlock(&ubi->wl_lock); + +out_free: + kfree(ec_hdr); + return err; +} + +/** + * check_protection_over - check if it is time to stop protecting some + * physical eraseblocks. + * @ubi: UBI device description object + * + * This function is called after each erase operation, when the absolute erase + * counter is incremented, to check if some physical eraseblock have not to be + * protected any longer. These physical eraseblocks are moved from the + * protection trees to the used tree. + */ +static void check_protection_over(struct ubi_device *ubi) +{ + struct ubi_wl_prot_entry *pe; + + /* + * There may be several protected physical eraseblock to remove, + * process them all. + */ + while (1) { + spin_lock(&ubi->wl_lock); + if (!ubi->prot.aec.rb_node) { + spin_unlock(&ubi->wl_lock); + break; + } + + pe = rb_entry(rb_first(&ubi->prot.aec), + struct ubi_wl_prot_entry, rb_aec); + + if (pe->abs_ec > ubi->abs_ec) { + spin_unlock(&ubi->wl_lock); + break; + } + + dbg_wl("PEB %d protection over, abs_ec %llu, PEB abs_ec %llu", + pe->e->pnum, ubi->abs_ec, pe->abs_ec); + rb_erase(&pe->rb_aec, &ubi->prot.aec); + rb_erase(&pe->rb_pnum, &ubi->prot.pnum); + wl_tree_add(pe->e, &ubi->used); + spin_unlock(&ubi->wl_lock); + + kfree(pe); + cond_resched(); + } +} + +/** + * schedule_ubi_work - schedule a work. + * @ubi: UBI device description object + * @wrk: the work to schedule + * + * This function enqueues a work defined by @wrk to the tail of the pending + * works list. + */ +static void schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk) +{ + spin_lock(&ubi->wl_lock); + list_add_tail(&wrk->list, &ubi->works); + ubi_assert(ubi->works_count >= 0); + ubi->works_count += 1; + if (ubi->thread_enabled) + wake_up_process(ubi->bgt_thread); + spin_unlock(&ubi->wl_lock); +} + +static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk, + int cancel); + +/** + * schedule_erase - schedule an erase work. + * @ubi: UBI device description object + * @e: the WL entry of the physical eraseblock to erase + * @torture: if the physical eraseblock has to be tortured + * + * This function returns zero in case of success and a %-ENOMEM in case of + * failure. + */ +static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, + int torture) +{ + struct ubi_work *wl_wrk; + + dbg_wl("schedule erasure of PEB %d, EC %d, torture %d", + e->pnum, e->ec, torture); + + wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS); + if (!wl_wrk) + return -ENOMEM; + + wl_wrk->func = &erase_worker; + wl_wrk->e = e; + wl_wrk->torture = torture; + + schedule_ubi_work(ubi, wl_wrk); + return 0; +} + +/** + * wear_leveling_worker - wear-leveling worker function. + * @ubi: UBI device description object + * @wrk: the work object + * @cancel: non-zero if the worker has to free memory and exit + * + * This function copies a more worn out physical eraseblock to a less worn out + * one. Returns zero in case of success and a negative error code in case of + * failure. + */ +static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk, + int cancel) +{ + int err, put = 0, scrubbing = 0, protect = 0; + struct ubi_wl_prot_entry *uninitialized_var(pe); + struct ubi_wl_entry *e1, *e2; + struct ubi_vid_hdr *vid_hdr; + + kfree(wrk); + + if (cancel) + return 0; + + vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); + if (!vid_hdr) + return -ENOMEM; + + mutex_lock(&ubi->move_mutex); + spin_lock(&ubi->wl_lock); + ubi_assert(!ubi->move_from && !ubi->move_to); + ubi_assert(!ubi->move_to_put); + + if (!ubi->free.rb_node || + (!ubi->used.rb_node && !ubi->scrub.rb_node)) { + /* + * No free physical eraseblocks? Well, they must be waiting in + * the queue to be erased. Cancel movement - it will be + * triggered again when a free physical eraseblock appears. + * + * No used physical eraseblocks? They must be temporarily + * protected from being moved. They will be moved to the + * @ubi->used tree later and the wear-leveling will be + * triggered again. + */ + dbg_wl("cancel WL, a list is empty: free %d, used %d", + !ubi->free.rb_node, !ubi->used.rb_node); + goto out_cancel; + } + + if (!ubi->scrub.rb_node) { + /* + * Now pick the least worn-out used physical eraseblock and a + * highly worn-out free physical eraseblock. If the erase + * counters differ much enough, start wear-leveling. + */ + e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb); + e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + + if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD)) { + dbg_wl("no WL needed: min used EC %d, max free EC %d", + e1->ec, e2->ec); + goto out_cancel; + } + paranoid_check_in_wl_tree(e1, &ubi->used); + rb_erase(&e1->rb, &ubi->used); + dbg_wl("move PEB %d EC %d to PEB %d EC %d", + e1->pnum, e1->ec, e2->pnum, e2->ec); + } else { + /* Perform scrubbing */ + scrubbing = 1; + e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, rb); + e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + paranoid_check_in_wl_tree(e1, &ubi->scrub); + rb_erase(&e1->rb, &ubi->scrub); + dbg_wl("scrub PEB %d to PEB %d", e1->pnum, e2->pnum); + } + + paranoid_check_in_wl_tree(e2, &ubi->free); + rb_erase(&e2->rb, &ubi->free); + ubi->move_from = e1; + ubi->move_to = e2; + spin_unlock(&ubi->wl_lock); + + /* + * Now we are going to copy physical eraseblock @e1->pnum to @e2->pnum. + * We so far do not know which logical eraseblock our physical + * eraseblock (@e1) belongs to. We have to read the volume identifier + * header first. + * + * Note, we are protected from this PEB being unmapped and erased. The + * 'ubi_wl_put_peb()' would wait for moving to be finished if the PEB + * which is being moved was unmapped. + */ + + err = ubi_io_read_vid_hdr(ubi, e1->pnum, vid_hdr, 0); + if (err && err != UBI_IO_BITFLIPS) { + if (err == UBI_IO_PEB_FREE) { + /* + * We are trying to move PEB without a VID header. UBI + * always write VID headers shortly after the PEB was + * given, so we have a situation when it did not have + * chance to write it down because it was preempted. + * Just re-schedule the work, so that next time it will + * likely have the VID header in place. + */ + dbg_wl("PEB %d has no VID header", e1->pnum); + goto out_not_moved; + } + + ubi_err("error %d while reading VID header from PEB %d", + err, e1->pnum); + if (err > 0) + err = -EIO; + goto out_error; + } + + err = ubi_eba_copy_leb(ubi, e1->pnum, e2->pnum, vid_hdr); + if (err) { + + if (err < 0) + goto out_error; + if (err == 1) + goto out_not_moved; + + /* + * For some reason the LEB was not moved - it might be because + * the volume is being deleted. We should prevent this PEB from + * being selected for wear-levelling movement for some "time", + * so put it to the protection tree. + */ + + dbg_wl("cancelled moving PEB %d", e1->pnum); + pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS); + if (!pe) { + err = -ENOMEM; + goto out_error; + } + + protect = 1; + } + + ubi_free_vid_hdr(ubi, vid_hdr); + spin_lock(&ubi->wl_lock); + if (protect) + prot_tree_add(ubi, e1, pe, protect); + if (!ubi->move_to_put) + wl_tree_add(e2, &ubi->used); + else + put = 1; + ubi->move_from = ubi->move_to = NULL; + ubi->move_to_put = ubi->wl_scheduled = 0; + spin_unlock(&ubi->wl_lock); + + if (put) { + /* + * Well, the target PEB was put meanwhile, schedule it for + * erasure. + */ + dbg_wl("PEB %d was put meanwhile, erase", e2->pnum); + err = schedule_erase(ubi, e2, 0); + if (err) + goto out_error; + } + + if (!protect) { + err = schedule_erase(ubi, e1, 0); + if (err) + goto out_error; + } + + + dbg_wl("done"); + mutex_unlock(&ubi->move_mutex); + return 0; + + /* + * For some reasons the LEB was not moved, might be an error, might be + * something else. @e1 was not changed, so return it back. @e2 might + * be changed, schedule it for erasure. + */ +out_not_moved: + ubi_free_vid_hdr(ubi, vid_hdr); + spin_lock(&ubi->wl_lock); + if (scrubbing) + wl_tree_add(e1, &ubi->scrub); + else + wl_tree_add(e1, &ubi->used); + ubi->move_from = ubi->move_to = NULL; + ubi->move_to_put = ubi->wl_scheduled = 0; + spin_unlock(&ubi->wl_lock); + + err = schedule_erase(ubi, e2, 0); + if (err) + goto out_error; + + mutex_unlock(&ubi->move_mutex); + return 0; + +out_error: + ubi_err("error %d while moving PEB %d to PEB %d", + err, e1->pnum, e2->pnum); + + ubi_free_vid_hdr(ubi, vid_hdr); + spin_lock(&ubi->wl_lock); + ubi->move_from = ubi->move_to = NULL; + ubi->move_to_put = ubi->wl_scheduled = 0; + spin_unlock(&ubi->wl_lock); + + kmem_cache_free(ubi_wl_entry_slab, e1); + kmem_cache_free(ubi_wl_entry_slab, e2); + ubi_ro_mode(ubi); + + mutex_unlock(&ubi->move_mutex); + return err; + +out_cancel: + ubi->wl_scheduled = 0; + spin_unlock(&ubi->wl_lock); + mutex_unlock(&ubi->move_mutex); + ubi_free_vid_hdr(ubi, vid_hdr); + return 0; +} + +/** + * ensure_wear_leveling - schedule wear-leveling if it is needed. + * @ubi: UBI device description object + * + * This function checks if it is time to start wear-leveling and schedules it + * if yes. This function returns zero in case of success and a negative error + * code in case of failure. + */ +static int ensure_wear_leveling(struct ubi_device *ubi) +{ + int err = 0; + struct ubi_wl_entry *e1; + struct ubi_wl_entry *e2; + struct ubi_work *wrk; + + spin_lock(&ubi->wl_lock); + if (ubi->wl_scheduled) + /* Wear-leveling is already in the work queue */ + goto out_unlock; + + /* + * If the ubi->scrub tree is not empty, scrubbing is needed, and the + * the WL worker has to be scheduled anyway. + */ + if (!ubi->scrub.rb_node) { + if (!ubi->used.rb_node || !ubi->free.rb_node) + /* No physical eraseblocks - no deal */ + goto out_unlock; + + /* + * We schedule wear-leveling only if the difference between the + * lowest erase counter of used physical eraseblocks and a high + * erase counter of free physical eraseblocks is greater then + * %UBI_WL_THRESHOLD. + */ + e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb); + e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF); + + if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD)) + goto out_unlock; + dbg_wl("schedule wear-leveling"); + } else + dbg_wl("schedule scrubbing"); + + ubi->wl_scheduled = 1; + spin_unlock(&ubi->wl_lock); + + wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS); + if (!wrk) { + err = -ENOMEM; + goto out_cancel; + } + + wrk->func = &wear_leveling_worker; + schedule_ubi_work(ubi, wrk); + return err; + +out_cancel: + spin_lock(&ubi->wl_lock); + ubi->wl_scheduled = 0; +out_unlock: + spin_unlock(&ubi->wl_lock); + return err; +} + +/** + * erase_worker - physical eraseblock erase worker function. + * @ubi: UBI device description object + * @wl_wrk: the work object + * @cancel: non-zero if the worker has to free memory and exit + * + * This function erases a physical eraseblock and perform torture testing if + * needed. It also takes care about marking the physical eraseblock bad if + * needed. Returns zero in case of success and a negative error code in case of + * failure. + */ +static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk, + int cancel) +{ + struct ubi_wl_entry *e = wl_wrk->e; + int pnum = e->pnum, err, need; + + if (cancel) { + dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec); + kfree(wl_wrk); + kmem_cache_free(ubi_wl_entry_slab, e); + return 0; + } + + dbg_wl("erase PEB %d EC %d", pnum, e->ec); + + err = sync_erase(ubi, e, wl_wrk->torture); + if (!err) { + /* Fine, we've erased it successfully */ + kfree(wl_wrk); + + spin_lock(&ubi->wl_lock); + ubi->abs_ec += 1; + wl_tree_add(e, &ubi->free); + spin_unlock(&ubi->wl_lock); + + /* + * One more erase operation has happened, take care about protected + * physical eraseblocks. + */ + check_protection_over(ubi); + + /* And take care about wear-leveling */ + err = ensure_wear_leveling(ubi); + return err; + } + + ubi_err("failed to erase PEB %d, error %d", pnum, err); + kfree(wl_wrk); + kmem_cache_free(ubi_wl_entry_slab, e); + + if (err == -EINTR || err == -ENOMEM || err == -EAGAIN || + err == -EBUSY) { + int err1; + + /* Re-schedule the LEB for erasure */ + err1 = schedule_erase(ubi, e, 0); + if (err1) { + err = err1; + goto out_ro; + } + return err; + } else if (err != -EIO) { + /* + * If this is not %-EIO, we have no idea what to do. Scheduling + * this physical eraseblock for erasure again would cause + * errors again and again. Well, lets switch to RO mode. + */ + goto out_ro; + } + + /* It is %-EIO, the PEB went bad */ + + if (!ubi->bad_allowed) { + ubi_err("bad physical eraseblock %d detected", pnum); + goto out_ro; + } + + spin_lock(&ubi->volumes_lock); + need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs + 1; + if (need > 0) { + need = ubi->avail_pebs >= need ? need : ubi->avail_pebs; + ubi->avail_pebs -= need; + ubi->rsvd_pebs += need; + ubi->beb_rsvd_pebs += need; + if (need > 0) + ubi_msg("reserve more %d PEBs", need); + } + + if (ubi->beb_rsvd_pebs == 0) { + spin_unlock(&ubi->volumes_lock); + ubi_err("no reserved physical eraseblocks"); + goto out_ro; + } + + spin_unlock(&ubi->volumes_lock); + ubi_msg("mark PEB %d as bad", pnum); + + err = ubi_io_mark_bad(ubi, pnum); + if (err) + goto out_ro; + + spin_lock(&ubi->volumes_lock); + ubi->beb_rsvd_pebs -= 1; + ubi->bad_peb_count += 1; + ubi->good_peb_count -= 1; + ubi_calculate_reserved(ubi); + if (ubi->beb_rsvd_pebs == 0) + ubi_warn("last PEB from the reserved pool was used"); + spin_unlock(&ubi->volumes_lock); + + return err; + +out_ro: + ubi_ro_mode(ubi); + return err; +} + +/** + * ubi_wl_put_peb - return a physical eraseblock to the wear-leveling unit. + * @ubi: UBI device description object + * @pnum: physical eraseblock to return + * @torture: if this physical eraseblock has to be tortured + * + * This function is called to return physical eraseblock @pnum to the pool of + * free physical eraseblocks. The @torture flag has to be set if an I/O error + * occurred to this @pnum and it has to be tested. This function returns zero + * in case of success, and a negative error code in case of failure. + */ +int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture) +{ + int err; + struct ubi_wl_entry *e; + + dbg_wl("PEB %d", pnum); + ubi_assert(pnum >= 0); + ubi_assert(pnum < ubi->peb_count); + +retry: + spin_lock(&ubi->wl_lock); + e = ubi->lookuptbl[pnum]; + if (e == ubi->move_from) { + /* + * User is putting the physical eraseblock which was selected to + * be moved. It will be scheduled for erasure in the + * wear-leveling worker. + */ + dbg_wl("PEB %d is being moved, wait", pnum); + spin_unlock(&ubi->wl_lock); + + /* Wait for the WL worker by taking the @ubi->move_mutex */ + mutex_lock(&ubi->move_mutex); + mutex_unlock(&ubi->move_mutex); + goto retry; + } else if (e == ubi->move_to) { + /* + * User is putting the physical eraseblock which was selected + * as the target the data is moved to. It may happen if the EBA + * unit already re-mapped the LEB in 'ubi_eba_copy_leb()' but + * the WL unit has not put the PEB to the "used" tree yet, but + * it is about to do this. So we just set a flag which will + * tell the WL worker that the PEB is not needed anymore and + * should be scheduled for erasure. + */ + dbg_wl("PEB %d is the target of data moving", pnum); + ubi_assert(!ubi->move_to_put); + ubi->move_to_put = 1; + spin_unlock(&ubi->wl_lock); + return 0; + } else { + if (in_wl_tree(e, &ubi->used)) { + paranoid_check_in_wl_tree(e, &ubi->used); + rb_erase(&e->rb, &ubi->used); + } else if (in_wl_tree(e, &ubi->scrub)) { + paranoid_check_in_wl_tree(e, &ubi->scrub); + rb_erase(&e->rb, &ubi->scrub); + } else { + err = prot_tree_del(ubi, e->pnum); + if (err) { + ubi_err("PEB %d not found", pnum); + ubi_ro_mode(ubi); + spin_unlock(&ubi->wl_lock); + return err; + } + } + } + spin_unlock(&ubi->wl_lock); + + err = schedule_erase(ubi, e, torture); + if (err) { + spin_lock(&ubi->wl_lock); + wl_tree_add(e, &ubi->used); + spin_unlock(&ubi->wl_lock); + } + + return err; +} + +/** + * ubi_wl_scrub_peb - schedule a physical eraseblock for scrubbing. + * @ubi: UBI device description object + * @pnum: the physical eraseblock to schedule + * + * If a bit-flip in a physical eraseblock is detected, this physical eraseblock + * needs scrubbing. This function schedules a physical eraseblock for + * scrubbing which is done in background. This function returns zero in case of + * success and a negative error code in case of failure. + */ +int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum) +{ + struct ubi_wl_entry *e; + + ubi_msg("schedule PEB %d for scrubbing", pnum); + +retry: + spin_lock(&ubi->wl_lock); + e = ubi->lookuptbl[pnum]; + if (e == ubi->move_from || in_wl_tree(e, &ubi->scrub)) { + spin_unlock(&ubi->wl_lock); + return 0; + } + + if (e == ubi->move_to) { + /* + * This physical eraseblock was used to move data to. The data + * was moved but the PEB was not yet inserted to the proper + * tree. We should just wait a little and let the WL worker + * proceed. + */ + spin_unlock(&ubi->wl_lock); + dbg_wl("the PEB %d is not in proper tree, retry", pnum); + yield(); + goto retry; + } + + if (in_wl_tree(e, &ubi->used)) { + paranoid_check_in_wl_tree(e, &ubi->used); + rb_erase(&e->rb, &ubi->used); + } else { + int err; + + err = prot_tree_del(ubi, e->pnum); + if (err) { + ubi_err("PEB %d not found", pnum); + ubi_ro_mode(ubi); + spin_unlock(&ubi->wl_lock); + return err; + } + } + + wl_tree_add(e, &ubi->scrub); + spin_unlock(&ubi->wl_lock); + + /* + * Technically scrubbing is the same as wear-leveling, so it is done + * by the WL worker. + */ + return ensure_wear_leveling(ubi); +} + +/** + * ubi_wl_flush - flush all pending works. + * @ubi: UBI device description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +int ubi_wl_flush(struct ubi_device *ubi) +{ + int err; + + /* + * Erase while the pending works queue is not empty, but not more then + * the number of currently pending works. + */ + dbg_wl("flush (%d pending works)", ubi->works_count); + while (ubi->works_count) { + err = do_work(ubi); + if (err) + return err; + } + + /* + * Make sure all the works which have been done in parallel are + * finished. + */ + down_write(&ubi->work_sem); + up_write(&ubi->work_sem); + + /* + * And in case last was the WL worker and it cancelled the LEB + * movement, flush again. + */ + while (ubi->works_count) { + dbg_wl("flush more (%d pending works)", ubi->works_count); + err = do_work(ubi); + if (err) + return err; + } + + return 0; +} + +/** + * tree_destroy - destroy an RB-tree. + * @root: the root of the tree to destroy + */ +static void tree_destroy(struct rb_root *root) +{ + struct rb_node *rb; + struct ubi_wl_entry *e; + + rb = root->rb_node; + while (rb) { + if (rb->rb_left) + rb = rb->rb_left; + else if (rb->rb_right) + rb = rb->rb_right; + else { + e = rb_entry(rb, struct ubi_wl_entry, rb); + + rb = rb_parent(rb); + if (rb) { + if (rb->rb_left == &e->rb) + rb->rb_left = NULL; + else + rb->rb_right = NULL; + } + + kmem_cache_free(ubi_wl_entry_slab, e); + } + } +} + +/** + * ubi_thread - UBI background thread. + * @u: the UBI device description object pointer + */ +int ubi_thread(void *u) +{ + int failures = 0; + struct ubi_device *ubi = u; + + ubi_msg("background thread \"%s\" started, PID %d", + ubi->bgt_name, task_pid_nr(current)); + + set_freezable(); + for (;;) { + int err; + + if (kthread_should_stop()) + break; + + if (try_to_freeze()) + continue; + + spin_lock(&ubi->wl_lock); + if (list_empty(&ubi->works) || ubi->ro_mode || + !ubi->thread_enabled) { + set_current_state(TASK_INTERRUPTIBLE); + spin_unlock(&ubi->wl_lock); + schedule(); + continue; + } + spin_unlock(&ubi->wl_lock); + + err = do_work(ubi); + if (err) { + ubi_err("%s: work failed with error code %d", + ubi->bgt_name, err); + if (failures++ > WL_MAX_FAILURES) { + /* + * Too many failures, disable the thread and + * switch to read-only mode. + */ + ubi_msg("%s: %d consecutive failures", + ubi->bgt_name, WL_MAX_FAILURES); + ubi_ro_mode(ubi); + break; + } + } else + failures = 0; + + cond_resched(); + } + + dbg_wl("background thread \"%s\" is killed", ubi->bgt_name); + return 0; +} + +/** + * cancel_pending - cancel all pending works. + * @ubi: UBI device description object + */ +static void cancel_pending(struct ubi_device *ubi) +{ + while (!list_empty(&ubi->works)) { + struct ubi_work *wrk; + + wrk = list_entry(ubi->works.next, struct ubi_work, list); + list_del(&wrk->list); + wrk->func(ubi, wrk, 1); + ubi->works_count -= 1; + ubi_assert(ubi->works_count >= 0); + } +} + +/** + * ubi_wl_init_scan - initialize the wear-leveling 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_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si) +{ + int err; + struct rb_node *rb1, *rb2; + struct ubi_scan_volume *sv; + struct ubi_scan_leb *seb, *tmp; + struct ubi_wl_entry *e; + + + ubi->used = ubi->free = ubi->scrub = RB_ROOT; + ubi->prot.pnum = ubi->prot.aec = RB_ROOT; + spin_lock_init(&ubi->wl_lock); + mutex_init(&ubi->move_mutex); + init_rwsem(&ubi->work_sem); + ubi->max_ec = si->max_ec; + INIT_LIST_HEAD(&ubi->works); + + sprintf(ubi->bgt_name, UBI_BGT_NAME_PATTERN, ubi->ubi_num); + + err = -ENOMEM; + ubi->lookuptbl = kzalloc(ubi->peb_count * sizeof(void *), GFP_KERNEL); + if (!ubi->lookuptbl) + return err; + + list_for_each_entry_safe(seb, tmp, &si->erase, u.list) { + cond_resched(); + + e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi->lookuptbl[e->pnum] = e; + if (schedule_erase(ubi, e, 0)) { + kmem_cache_free(ubi_wl_entry_slab, e); + goto out_free; + } + } + + list_for_each_entry(seb, &si->free, u.list) { + cond_resched(); + + e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi_assert(e->ec >= 0); + wl_tree_add(e, &ubi->free); + ubi->lookuptbl[e->pnum] = e; + } + + list_for_each_entry(seb, &si->corr, u.list) { + cond_resched(); + + e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi->lookuptbl[e->pnum] = e; + if (schedule_erase(ubi, e, 0)) { + kmem_cache_free(ubi_wl_entry_slab, e); + goto out_free; + } + } + + ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { + ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) { + cond_resched(); + + e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL); + if (!e) + goto out_free; + + e->pnum = seb->pnum; + e->ec = seb->ec; + ubi->lookuptbl[e->pnum] = e; + if (!seb->scrub) { + dbg_wl("add PEB %d EC %d to the used tree", + e->pnum, e->ec); + wl_tree_add(e, &ubi->used); + } else { + dbg_wl("add PEB %d EC %d to the scrub tree", + e->pnum, e->ec); + wl_tree_add(e, &ubi->scrub); + } + } + } + + if (ubi->avail_pebs < WL_RESERVED_PEBS) { + ubi_err("no enough physical eraseblocks (%d, need %d)", + ubi->avail_pebs, WL_RESERVED_PEBS); + goto out_free; + } + ubi->avail_pebs -= WL_RESERVED_PEBS; + ubi->rsvd_pebs += WL_RESERVED_PEBS; + + /* Schedule wear-leveling if needed */ + err = ensure_wear_leveling(ubi); + if (err) + goto out_free; + + return 0; + +out_free: + cancel_pending(ubi); + tree_destroy(&ubi->used); + tree_destroy(&ubi->free); + tree_destroy(&ubi->scrub); + kfree(ubi->lookuptbl); + return err; +} + +/** + * protection_trees_destroy - destroy the protection RB-trees. + * @ubi: UBI device description object + */ +static void protection_trees_destroy(struct ubi_device *ubi) +{ + struct rb_node *rb; + struct ubi_wl_prot_entry *pe; + + rb = ubi->prot.aec.rb_node; + while (rb) { + if (rb->rb_left) + rb = rb->rb_left; + else if (rb->rb_right) + rb = rb->rb_right; + else { + pe = rb_entry(rb, struct ubi_wl_prot_entry, rb_aec); + + rb = rb_parent(rb); + if (rb) { + if (rb->rb_left == &pe->rb_aec) + rb->rb_left = NULL; + else + rb->rb_right = NULL; + } + + kmem_cache_free(ubi_wl_entry_slab, pe->e); + kfree(pe); + } + } +} + +/** + * ubi_wl_close - close the wear-leveling unit. + * @ubi: UBI device description object + */ +void ubi_wl_close(struct ubi_device *ubi) +{ + dbg_wl("close the UBI wear-leveling unit"); + + cancel_pending(ubi); + protection_trees_destroy(ubi); + tree_destroy(&ubi->used); + tree_destroy(&ubi->free); + tree_destroy(&ubi->scrub); + kfree(ubi->lookuptbl); +} + +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID + +/** + * paranoid_check_ec - make sure that the erase counter of a physical eraseblock + * is correct. + * @ubi: UBI device description object + * @pnum: the physical eraseblock number to check + * @ec: the erase counter to check + * + * This function returns zero if the erase counter of physical eraseblock @pnum + * is equivalent to @ec, %1 if not, and a negative error code if an error + * occurred. + */ +static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec) +{ + int err; + long long read_ec; + struct ubi_ec_hdr *ec_hdr; + + ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS); + if (!ec_hdr) + return -ENOMEM; + + err = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0); + if (err && err != UBI_IO_BITFLIPS) { + /* The header does not have to exist */ + err = 0; + goto out_free; + } + + read_ec = be64_to_cpu(ec_hdr->ec); + if (ec != read_ec) { + ubi_err("paranoid check failed for PEB %d", pnum); + ubi_err("read EC is %lld, should be %d", read_ec, ec); + ubi_dbg_dump_stack(); + err = 1; + } else + err = 0; + +out_free: + kfree(ec_hdr); + return err; +} + +/** + * paranoid_check_in_wl_tree - make sure that a wear-leveling entry is present + * in a WL RB-tree. + * @e: the wear-leveling entry to check + * @root: the root of the tree + * + * This function returns zero if @e is in the @root RB-tree and %1 if it + * is not. + */ +static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e, + struct rb_root *root) +{ + if (in_wl_tree(e, root)) + return 0; + + ubi_err("paranoid check failed for PEB %d, EC %d, RB-tree %p ", + e->pnum, e->ec, root); + ubi_dbg_dump_stack(); + return 1; +} + +#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ |