This is a note to let you know that I've just added the patch titled ubi: Make recover_peb power cut aware to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ubi-make-recover_peb-power-cut-aware.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 972228d87445dc46c0a01f5f3de673ac017626f7 Mon Sep 17 00:00:00 2001 From: Richard Weinberger <richard@xxxxxx> Date: Tue, 21 Jun 2016 00:31:50 +0200 Subject: ubi: Make recover_peb power cut aware MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -575,6 +575,7 @@ 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) @@ -599,14 +600,8 @@ retry: goto out_put; } - vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); - err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr); - if (err) { - up_read(&ubi->fm_eba_sem); - goto write_error; - } + ubi_assert(vid_hdr->vol_type == UBI_VID_DYNAMIC); - data_size = offset + len; mutex_lock(&ubi->buf_mutex); memset(ubi->peb_buf + offset, 0xFF, len); @@ -621,6 +616,19 @@ retry: memcpy(ubi->peb_buf + offset, buf, len); + data_size = offset + len; + crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size); + vid_hdr->sqnum = cpu_to_be64(ubi_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); + up_read(&ubi->fm_eba_sem); + goto write_error; + } + err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size); if (err) { mutex_unlock(&ubi->buf_mutex); Patches currently in stable-queue which might be from richard@xxxxxx are queue-4.4/ubifs-implement-migratepage.patch queue-4.4/ubi-make-recover_peb-power-cut-aware.patch queue-4.4/mm-export-migrate_page_move_mapping-and-migrate_page_copy.patch -- 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