UBI: remember copy_flag while scanning

While scanning the flash we read all VID headers and store some important
information in 'struct ubi_scan_leb'. Store also the 'copy_flag' value there
as it is needed when comparing LEBs. We do not increase memory consumption
because this is just one bit and we have plenty of spare bits in
'struct ubi_scan_leb' (sizeof(struct ubi_scan_leb) is 48 both with and
without this patch).

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 30b710216f264cf2c43095ea65f48876b18ef741..2fbb571b9828720c98f190c4a3150f1dae15951d 100644 (file)
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -330,12 +330,18 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
                        return 1;
                }
        } else {
-               pnum = seb->pnum;
+               if (!seb->copy_flag) {
+                       /* It is not a copy, so it is newer */
+                       dbg_bld("first PEB %d is newer, copy_flag is unset",
+                               pnum);
+                       return bitflips << 1;
+               }
 
                vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
                if (!vh)
                        return -ENOMEM;
 
+               pnum = seb->pnum;
                err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
                if (err) {
                        if (err == UBI_IO_BITFLIPS)
@@ -350,14 +356,6 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
                        }
                }
 
-               if (!vh->copy_flag) {
-                       /* It is not a copy, so it is newer */
-                       dbg_bld("first PEB %d is newer, copy_flag is unset",
-                               pnum);
-                       err = bitflips << 1;
-                       goto out_free_vidh;
-               }
-
                vid_hdr = vh;
        }
 
@@ -516,6 +514,7 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
                        seb->ec = ec;
                        seb->pnum = pnum;
                        seb->scrub = ((cmp_res & 2) || bitflips);
+                       seb->copy_flag = vid_hdr->copy_flag;
                        seb->sqnum = sqnum;
 
                        if (sv->highest_lnum == lnum)
@@ -549,8 +548,9 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
        seb->ec = ec;
        seb->pnum = pnum;
        seb->lnum = lnum;
-       seb->sqnum = sqnum;
        seb->scrub = bitflips;
+       seb->copy_flag = vid_hdr->copy_flag;
+       seb->sqnum = sqnum;
 
        if (sv->highest_lnum <= lnum) {
                sv->highest_lnum = lnum;

diff --git a/drivers/mtd/ubi/scan.h b/drivers/mtd/ubi/scan.h
index 12ac852c993be4b636ab21084f4f2c2eb34bf2f4..a3264f0bef2b825d3df88b40480dc390cfa94860 100644 (file)
--- a/drivers/mtd/ubi/scan.h
+++ b/drivers/mtd/ubi/scan.h
@@ -30,6 +30,7 @@
  * @pnum: physical eraseblock number
  * @lnum: logical eraseblock number
  * @scrub: if this physical eraseblock needs scrubbing
+ * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
  * @sqnum: sequence number
  * @u: unions RB-tree or @list links
  * @u.rb: link in the per-volume RB-tree of &struct ubi_scan_leb objects
@@ -42,7 +43,8 @@ struct ubi_scan_leb {
        int ec;
        int pnum;
        int lnum;
-       int scrub;
+       unsigned int scrub:1;
+       unsigned int copy_flag:1;
        unsigned long long sqnum;
        union {
                struct rb_node rb;