Commit e66d5f6e authored by Richard Weinberger's avatar Richard Weinberger Committed by Ben Hutchings

ubi: Make recover_peb power cut aware

commit 972228d8 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: default avatarJörg Pfähler <pfaehler@isse.de>
Reviewed-by: default avatarJörg Pfähler <pfaehler@isse.de>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
[bwh: Backported to 3.16: no need to unlock ubi->fm_eba_sem on error]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent da0b96a9
......@@ -521,6 +521,7 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
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)
......@@ -542,12 +543,8 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
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)
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);
......@@ -560,6 +557,18 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
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);
goto write_error;
}
err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size);
if (err) {
mutex_unlock(&ubi->buf_mutex);
......
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