fiemap: De-obfuscate last_logical and cur_extent manipulation

last_logical and cur_extent are being passed by reference to the printing
functions and the in turn modify those variables. This makes it a bit harder to
reason about the code. So change the printing function to take those 2 arguemnts
by value and move the manipulation logic in fiemap_f. Furthermore, the printing
function now return the number of extents they have printed (either 1 or 2,
dependent on whether we've hit the -n limit). No functional changes

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/io/fiemap.c b/io/fiemap.c
index a31db790c86d7493769c6fbaa43755168867e1cf..0f04b874fd5f66d0b120ee2e59a96c8de05444a9 100644 (file)
--- a/io/fiemap.c
+++ b/io/fiemap.c
@@ -52,15 +52,15 @@ fiemap_help(void)
 "\n"));
 }
 
-static void
+static int
 print_verbose(
        struct fiemap_extent    *extent,
        int                     foff_w,
        int                     boff_w,
        int                     tot_w,
        int                     flg_w,
-       int                     *cur_extent,
-       __u64                   *last_logical)
+       int                     cur_extent,
+       __u64                   last_logical)
 {
        __u64                   lstart;
        __u64                   llast;
@@ -70,7 +70,7 @@ print_verbose(
        char                    bbuf[48];
        char                    flgbuf[16];
 
-       llast = BTOBBT(*last_logical);
+       llast = BTOBBT(last_logical);
        lstart = BTOBBT(extent->fe_logical);
        len = BTOBBT(extent->fe_length);
        block = BTOBBT(extent->fe_physical);
@@ -78,7 +78,7 @@ print_verbose(
        memset(lbuf, 0, sizeof(lbuf));
        memset(bbuf, 0, sizeof(bbuf));
 
-       if (*cur_extent == 0) {
+       if (cur_extent == 0) {
                printf("%4s: %-*s %-*s %*s %*s\n", _("EXT"),
                        foff_w, _("FILE-OFFSET"),
                        boff_w, _("BLOCK-RANGE"),
@@ -89,57 +89,56 @@ print_verbose(
        if (lstart != llast) {
                snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", llast,
                         lstart - 1ULL);
-               printf("%4d: %-*s %-*s %*llu\n", *cur_extent, foff_w, lbuf,
+               printf("%4d: %-*s %-*s %*llu\n", cur_extent, foff_w, lbuf,
                       boff_w, _("hole"), tot_w, lstart - llast);
-               (*cur_extent)++;
                memset(lbuf, 0, sizeof(lbuf));
+               cur_extent++;
        }
 
-       if ((*cur_extent + 1) == max_extents)
-               return;
+       if ((cur_extent + 1) == max_extents)
+               return 1;
 
        snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", lstart,
                 lstart + len - 1ULL);
        snprintf(bbuf, sizeof(bbuf), "%llu..%llu", block, block + len - 1ULL);
        snprintf(flgbuf, sizeof(flgbuf), "0x%x", extent->fe_flags);
-       printf("%4d: %-*s %-*s %*llu %*s\n", *cur_extent, foff_w, lbuf,
+       printf("%4d: %-*s %-*s %*llu %*s\n", cur_extent, foff_w, lbuf,
               boff_w, bbuf, tot_w, len, flg_w, flgbuf);
 
-       (*cur_extent)++;
-       *last_logical = extent->fe_logical + extent->fe_length;
+       return 2;
 }
 
-static void
+static int
 print_plain(
        struct fiemap_extent    *extent,
        int                     lflag,
-       int                     *cur_extent,
-       __u64                   *last_logical)
+       int                     cur_extent,
+       __u64                   last_logical)
 {
        __u64                   lstart;
        __u64                   llast;
        __u64                   block;
        __u64                   len;
 
-       llast = BTOBBT(*last_logical);
+       llast = BTOBBT(last_logical);
        lstart = BTOBBT(extent->fe_logical);
        len = BTOBBT(extent->fe_length);
        block = BTOBBT(extent->fe_physical);
 
        if (lstart != llast) {
-               printf("\t%d: [%llu..%llu]: hole", *cur_extent,
+               printf("\t%d: [%llu..%llu]: hole", cur_extent,
                       llast, lstart - 1ULL);
                if (lflag)
                        printf(_(" %llu blocks\n"), lstart - llast);
                else
                        printf("\n");
-               (*cur_extent)++;
+               cur_extent++;
        }
 
-       if ((*cur_extent + 1) == max_extents)
-               return;
+       if ((cur_extent + 1) == max_extents)
+               return 1;
 
-       printf("\t%d: [%llu..%llu]: %llu..%llu", *cur_extent,
+       printf("\t%d: [%llu..%llu]: %llu..%llu", cur_extent,
               lstart, lstart + len - 1ULL, block,
               block + len - 1ULL);
 
@@ -147,8 +146,7 @@ print_plain(
                printf(_(" %llu blocks\n"), len);
        else
                printf("\n");
-       (*cur_extent)++;
-       *last_logical = extent->fe_logical + extent->fe_length;
+       return 2;
 }
 
 /*
@@ -267,6 +265,7 @@ fiemap_f(
 
                for (i = 0; i < fiemap->fm_mapped_extents; i++) {
                        struct fiemap_extent    *extent;
+                       int num_printed = 0;
 
                        extent = &fiemap->fm_extents[i];
                        if (vflag) {
@@ -276,12 +275,17 @@ fiemap_f(
                                                          &flg_w);
                                }
 
-                               print_verbose(extent, foff_w, boff_w, tot_w,
-                                             flg_w, &cur_extent,
-                                             &last_logical);
+                               num_printed = print_verbose(extent, foff_w,
+                                                           boff_w, tot_w,
+                                                           flg_w, cur_extent,
+                                                           last_logical);
                        } else
-                               print_plain(extent, lflag, &cur_extent,
-                                           &last_logical);
+                               num_printed = print_plain(extent, lflag,
+                                                         cur_extent,
+                                                         last_logical);
+
+                       cur_extent += num_printed;
+                       last_logical = extent->fe_logical + extent->fe_length;
 
                        if (extent->fe_flags & FIEMAP_EXTENT_LAST) {
                                last = 1;