UBI: change cascade of ifs to switch statements

This patch improves readability and simplifies scanning code by changing a
long cascade of 'if' statements to a switch statement. This should presumably
be a little faster as well.

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

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index a15e9bc..9405e24 100644 (file)
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -746,11 +746,18 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
        err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
        if (err < 0)
                return err;
-       else if (err == UBI_IO_BITFLIPS)
+       switch (err) {
+       case 0:
+               break;
+       case UBI_IO_BITFLIPS:
                bitflips = 1;
-       else if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS)
+               break;
+       case UBI_IO_FF:
+       case UBI_IO_FF_BITFLIPS:
                return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
-       else if (err == UBI_IO_BAD_HDR_EBADMSG || err == UBI_IO_BAD_HDR) {
+       case UBI_IO_BAD_HDR_EBADMSG:
+               si->read_err_count += 1;
+       case UBI_IO_BAD_HDR:
                /*
                 * We have to also look at the VID header, possibly it is not
                 * corrupted. Set %bitflips flag in order to make this PEB be
@@ -759,6 +766,10 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
                ec_err = err;
                ec = UBI_SCAN_UNKNOWN_EC;
                bitflips = 1;
+               break;
+       default:
+               ubi_err("'ubi_io_read_ec_hdr()' returned unknown code %d", err);
+               return -EINVAL;
        }
 
        if (!ec_err) {
@@ -814,24 +825,32 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
        err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
        if (err < 0)
                return err;
-       else if (err == UBI_IO_BITFLIPS)
+       switch (err) {
+       case 0:
+               break;
+       case UBI_IO_BITFLIPS:
                bitflips = 1;
-       else if (err == UBI_IO_BAD_HDR_EBADMSG || err == UBI_IO_BAD_HDR ||
-                (err == UBI_IO_FF && ec_err) || err == UBI_IO_FF_BITFLIPS) {
-               /* VID header is corrupted */
-               if (err == UBI_IO_BAD_HDR_EBADMSG ||
-                   ec_err == UBI_IO_BAD_HDR_EBADMSG)
-                       si->read_err_count += 1;
+               break;
+       case UBI_IO_BAD_HDR_EBADMSG:
+               si->read_err_count += 1;
+       case UBI_IO_BAD_HDR:
+       case UBI_IO_FF_BITFLIPS:
                err = add_to_list(si, pnum, ec, &si->corr);
                if (err)
                        return err;
                goto adjust_mean_ec;
-       } else if (err == UBI_IO_FF) {
-               /* No VID header - the physical eraseblock is free */
-               err = add_to_list(si, pnum, ec, &si->free);
+       case UBI_IO_FF:
+               if (ec_err)
+                       err = add_to_list(si, pnum, ec, &si->corr);
+               else
+                       err = add_to_list(si, pnum, ec, &si->free);
                if (err)
                        return err;
                goto adjust_mean_ec;
+       default:
+               ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d",
+                       err);
+               return -EINVAL;
        }
 
        vol_id = be32_to_cpu(vidh->vol_id);