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authorRichard Weinberger <richard@nod.at>2016-06-21 01:31:50 +0300
committerRichard Weinberger <richard@nod.at>2016-06-23 01:29:32 +0300
commit972228d87445dc46c0a01f5f3de673ac017626f7 (patch)
tree41cf6d89bcc2899d00d52b46d4333179f4903e50 /drivers/mtd
parentc0a1ecb9f4e208f4b75d88fa9669748e3fd705ab (diff)
downloadlinux-972228d87445dc46c0a01f5f3de673ac017626f7.tar.xz
ubi: Make recover_peb power cut aware
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. Cc: stable@vger.kernel.org Reported-by: Jörg Pfähler <pfaehler@isse.de> Reviewed-by: Jörg Pfähler <pfaehler@isse.de> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/ubi/eba.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 5780dd1ba79d..ebf517271d29 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -575,6 +575,7 @@ 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)
@@ -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);