diff options
Diffstat (limited to 'drivers/mtd/ubi/scan.c')
-rw-r--r-- | drivers/mtd/ubi/scan.c | 131 |
1 files changed, 101 insertions, 30 deletions
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c index aed19f33b8f..372a15ac999 100644 --- a/drivers/mtd/ubi/scan.c +++ b/drivers/mtd/ubi/scan.c @@ -44,6 +44,7 @@ #include <linux/slab.h> #include <linux/crc32.h> #include <linux/math64.h> +#include <linux/random.h> #include "ubi.h" #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID @@ -72,16 +73,19 @@ static int add_to_list(struct ubi_scan_info *si, int pnum, int ec, { struct ubi_scan_leb *seb; - if (list == &si->free) + if (list == &si->free) { dbg_bld("add to free: PEB %d, EC %d", pnum, ec); - else if (list == &si->erase) + si->free_peb_count += 1; + } else if (list == &si->erase) { dbg_bld("add to erase: PEB %d, EC %d", pnum, ec); - else if (list == &si->corr) { + si->erase_peb_count += 1; + } else if (list == &si->corr) { dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec); - si->corr_count += 1; - } else if (list == &si->alien) + si->corr_peb_count += 1; + } else if (list == &si->alien) { dbg_bld("add to alien: PEB %d, EC %d", pnum, ec); - else + si->alien_peb_count += 1; + } else BUG(); seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL); @@ -517,6 +521,7 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si, sv->leb_count += 1; rb_link_node(&seb->u.rb, parent, p); rb_insert_color(&seb->u.rb, &sv->root); + si->used_peb_count += 1; return 0; } @@ -745,19 +750,17 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, bitflips = 1; else if (err == UBI_IO_PEB_EMPTY) return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase); - else if (err == UBI_IO_BAD_EC_HDR) { + else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR) { /* * We have to also look at the VID header, possibly it is not * corrupted. Set %bitflips flag in order to make this PEB be * moved and EC be re-created. */ - ec_corr = 1; + ec_corr = err; ec = UBI_SCAN_UNKNOWN_EC; bitflips = 1; } - si->is_empty = 0; - if (!ec_corr) { int image_seq; @@ -813,9 +816,12 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, return err; else if (err == UBI_IO_BITFLIPS) bitflips = 1; - else if (err == UBI_IO_BAD_VID_HDR || + else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR || (err == UBI_IO_PEB_FREE && ec_corr)) { /* VID header is corrupted */ + if (err == UBI_IO_BAD_HDR_READ || + ec_corr == UBI_IO_BAD_HDR_READ) + si->read_err_count += 1; err = add_to_list(si, pnum, ec, &si->corr); if (err) return err; @@ -836,11 +842,11 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, switch (vidh->compat) { case UBI_COMPAT_DELETE: ubi_msg("\"delete\" compatible internal volume %d:%d" - " found, remove it", vol_id, lnum); + " found, will remove it", vol_id, lnum); err = add_to_list(si, pnum, ec, &si->corr); if (err) return err; - break; + return 0; case UBI_COMPAT_RO: ubi_msg("read-only compatible internal volume %d:%d" @@ -855,7 +861,6 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, err = add_to_list(si, pnum, ec, &si->alien); if (err) return err; - si->alien_peb_count += 1; return 0; case UBI_COMPAT_REJECT: @@ -886,6 +891,85 @@ adjust_mean_ec: } /** + * check_what_we_have - check what PEB were found by scanning. + * @ubi: UBI device description object + * @si: scanning information + * + * This is a helper function which takes a look what PEBs were found by + * scanning, and decides whether the flash is empty and should be formatted and + * whether there are too many corrupted PEBs and we should not attach this + * MTD device. Returns zero if we should proceed with attaching the MTD device, + * and %-EINVAL if we should not. + */ +static int check_what_we_have(struct ubi_device *ubi, struct ubi_scan_info *si) +{ + struct ubi_scan_leb *seb; + int max_corr; + + max_corr = ubi->peb_count - si->bad_peb_count - si->alien_peb_count; + max_corr = max_corr / 20 ?: 8; + + /* + * Few corrupted PEBs are not a problem and may be just a result of + * unclean reboots. However, many of them may indicate some problems + * with the flash HW or driver. + */ + if (si->corr_peb_count >= 8) { + ubi_warn("%d PEBs are corrupted", si->corr_peb_count); + printk(KERN_WARNING "corrupted PEBs are:"); + list_for_each_entry(seb, &si->corr, u.list) + printk(KERN_CONT " %d", seb->pnum); + printk(KERN_CONT "\n"); + + /* + * If too many PEBs are corrupted, we refuse attaching, + * otherwise, only print a warning. + */ + if (si->corr_peb_count >= max_corr) { + ubi_err("too many corrupted PEBs, refusing this device"); + return -EINVAL; + } + } + + if (si->free_peb_count + si->used_peb_count + + si->alien_peb_count == 0) { + /* No UBI-formatted eraseblocks were found */ + if (si->corr_peb_count == si->read_err_count && + si->corr_peb_count < 8) { + /* No or just few corrupted PEBs, and all of them had a + * read error. We assume that those are bad PEBs, which + * were just not marked as bad so far. + * + * This piece of code basically tries to distinguish + * between the following 2 situations: + * + * 1. Flash is empty, but there are few bad PEBs, which + * are not marked as bad so far, and which were read + * with error. We want to go ahead and format this + * flash. While formating, the faulty PEBs will + * probably be marked as bad. + * + * 2. Flash probably contains non-UBI data and we do + * not want to format it and destroy possibly needed + * data (e.g., consider the case when the bootloader + * MTD partition was accidentally fed to UBI). + */ + si->is_empty = 1; + ubi_msg("empty MTD device detected"); + get_random_bytes(&ubi->image_seq, sizeof(ubi->image_seq)); + } else { + ubi_err("MTD device possibly contains non-UBI data, " + "refusing it"); + return -EINVAL; + } + } + + if (si->corr_peb_count > 0) + ubi_msg("corrupted PEBs will be formatted"); + return 0; +} + +/** * ubi_scan - scan an MTD device. * @ubi: UBI device description object * @@ -909,7 +993,6 @@ struct ubi_scan_info *ubi_scan(struct ubi_device *ubi) INIT_LIST_HEAD(&si->erase); INIT_LIST_HEAD(&si->alien); si->volumes = RB_ROOT; - si->is_empty = 1; err = -ENOMEM; ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); @@ -935,21 +1018,9 @@ struct ubi_scan_info *ubi_scan(struct ubi_device *ubi) if (si->ec_count) si->mean_ec = div_u64(si->ec_sum, si->ec_count); - if (si->is_empty) - ubi_msg("empty MTD device detected"); - - /* - * Few corrupted PEBs are not a problem and may be just a result of - * unclean reboots. However, many of them may indicate some problems - * with the flash HW or driver. Print a warning in this case. - */ - if (si->corr_count >= 8 || si->corr_count >= ubi->peb_count / 4) { - ubi_warn("%d PEBs are corrupted", si->corr_count); - printk(KERN_WARNING "corrupted PEBs are:"); - list_for_each_entry(seb, &si->corr, u.list) - printk(KERN_CONT " %d", seb->pnum); - printk(KERN_CONT "\n"); - } + err = check_what_we_have(ubi, si); + if (err) + goto out_vidh; /* * In case of unknown erase counter we use the mean erase counter |