diff options
| -rw-r--r-- | drivers/mtd/ubi/eba.c | 90 |
1 files changed, 89 insertions, 1 deletions
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index 250e30fac61b..593a4f9d97e3 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -490,6 +490,82 @@ out_unlock: return err; } +#ifdef CONFIG_MTD_UBI_FASTMAP +/** + * check_mapping - check and fixup a mapping + * @ubi: UBI device description object + * @vol: volume description object + * @lnum: logical eraseblock number + * @pnum: physical eraseblock number + * + * Checks whether a given mapping is valid. Fastmap cannot track LEB unmap + * operations, if such an operation is interrupted the mapping still looks + * good, but upon first read an ECC is reported to the upper layer. + * Normaly during the full-scan at attach time this is fixed, for Fastmap + * we have to deal with it while reading. + * If the PEB behind a LEB shows this symthom we change the mapping to + * %UBI_LEB_UNMAPPED and schedule the PEB for erasure. + * + * Returns 0 on success, negative error code in case of failure. + */ +static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, + int *pnum) +{ + int err; + struct ubi_vid_io_buf *vidb; + + if (!ubi->fast_attach) + return 0; + + vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS); + if (!vidb) + return -ENOMEM; + + err = ubi_io_read_vid_hdr(ubi, *pnum, vidb, 0); + if (err > 0 && err != UBI_IO_BITFLIPS) { + int torture = 0; + + switch (err) { + case UBI_IO_FF: + case UBI_IO_FF_BITFLIPS: + case UBI_IO_BAD_HDR: + case UBI_IO_BAD_HDR_EBADMSG: + break; + default: + ubi_assert(0); + } + + if (err == UBI_IO_BAD_HDR_EBADMSG || err == UBI_IO_FF_BITFLIPS) + torture = 1; + + down_read(&ubi->fm_eba_sem); + vol->eba_tbl->entries[lnum].pnum = UBI_LEB_UNMAPPED; + up_read(&ubi->fm_eba_sem); + ubi_wl_put_peb(ubi, vol->vol_id, lnum, *pnum, torture); + + *pnum = UBI_LEB_UNMAPPED; + } else if (err < 0) { + ubi_err(ubi, "unable to read VID header back from PEB %i: %i", + *pnum, err); + + goto out_free; + } + + err = 0; + +out_free: + ubi_free_vid_buf(vidb); + + return err; +} +#else +static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, + int *pnum) +{ + return 0; +} +#endif + /** * ubi_eba_read_leb - read data. * @ubi: UBI device description object @@ -522,7 +598,13 @@ int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, return err; pnum = vol->eba_tbl->entries[lnum].pnum; - if (pnum < 0) { + if (pnum >= 0) { + err = check_mapping(ubi, vol, lnum, &pnum); + if (err < 0) + goto out_unlock; + } + + if (pnum == UBI_LEB_UNMAPPED) { /* * The logical eraseblock is not mapped, fill the whole buffer * with 0xFF bytes. The exception is static volumes for which @@ -931,6 +1013,12 @@ int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, pnum = vol->eba_tbl->entries[lnum].pnum; if (pnum >= 0) { + err = check_mapping(ubi, vol, lnum, &pnum); + if (err < 0) + goto out; + } + + if (pnum >= 0) { dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d", len, offset, vol_id, lnum, pnum); |