3.2.82-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Richard Weinberger <richard@xxxxxx> commit 972228d87445dc46c0a01f5f3de673ac017626f7 upstream. recover_peb() was never power cut aware, if a power cut happened right after writing the VID header upon next attach UBI would blindly use the new partial written PEB and all data from the old PEB is lost. In order to make recover_peb() power cut aware, write the new VID with a proper crc and copy_flag set such that the UBI attach process will detect whether the new PEB is completely written or not. We cannot directly use ubi_eba_atomic_leb_change() since we'd have to unlock the LEB which is facing a write error. Reported-by: Jörg Pfähler <pfaehler@xxxxxxx> Reviewed-by: Jörg Pfähler <pfaehler@xxxxxxx> Signed-off-by: Richard Weinberger <richard@xxxxxx> [bwh: Backported to 3.2: - Adjust context - Use next_sqnum() instead of ubi_next_sqnum() - Use ubi_device::peb_buf1 instead of ubi_device::peb_buf - No need to unlock ubi->fm_eba_sem on error] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/mtd/ubi/eba.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -501,6 +501,7 @@ static int recover_peb(struct ubi_device int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0; struct ubi_volume *vol = ubi->volumes[idx]; struct ubi_vid_hdr *vid_hdr; + uint32_t crc; vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) @@ -522,12 +523,8 @@ retry: goto out_put; } - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); - err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr); - if (err) - goto write_error; + ubi_assert(vid_hdr->vol_type == UBI_VID_DYNAMIC); - data_size = offset + len; mutex_lock(&ubi->buf_mutex); memset(ubi->peb_buf1 + offset, 0xFF, len); @@ -540,6 +537,18 @@ retry: memcpy(ubi->peb_buf1 + offset, buf, len); + data_size = offset + len; + crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size); + vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->copy_flag = 1; + vid_hdr->data_size = cpu_to_be32(data_size); + vid_hdr->data_crc = cpu_to_be32(crc); + err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr); + if (err) { + mutex_unlock(&ubi->buf_mutex); + goto write_error; + } + err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size); if (err) { mutex_unlock(&ubi->buf_mutex); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html