filefrag: Fix calculation of ideal number of extents

Fix calculation of the ideal number of extents needed for a file to
take into account sparse files.

In addition, suppress the "this file is extent-based" message unless
verbose mode is enabled.

Addresses-Debian-Bug: #458306

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/misc/filefrag.c b/misc/filefrag.c
index 79f8faf..526b906 100644 (file)
--- a/misc/filefrag.c
+++ b/misc/filefrag.c
@@ -83,7 +83,7 @@ static void frag_report(const char *filename)
 #endif
        int             bs;
        long            fd;
-       unsigned long   block, last_block = 0, numblocks, i;
+       unsigned long   block, last_block = 0, numblocks, i, count;
        long            bpib;   /* Blocks per indirect block */
        long            cylgroups;
        int             discont = 0, expected;
@@ -135,7 +135,8 @@ static void frag_report(const char *filename)
        if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
                flags = 0;
        if (flags & EXT4_EXTENTS_FL) {
-               printf("File is stored in extents format\n");
+               if (verbose)
+                       printf("File is stored in extents format\n");
                is_ext2 = 0;
        }
        if (verbose)
@@ -148,7 +149,7 @@ static void frag_report(const char *filename)
                printf("First block: %lu\nLast block: %lu\n",
                       get_bmap(fd, 0), get_bmap(fd, numblocks - 1));
        }
-       for (i=0; i < numblocks; i++) {
+       for (i=0, count=0; i < numblocks; i++) {
                if (is_ext2 && last_block) {
                        if (((i-EXT2_DIRECT) % bpib) == 0)
                                last_block++;
@@ -160,6 +161,7 @@ static void frag_report(const char *filename)
                block = get_bmap(fd, i);
                if (block == 0)
                        continue;
+               count++;
                if (last_block && (block != last_block +1) ) {
                        if (verbose)
                                printf("Discontinuity: Block %ld is at %lu (was %lu)\n",
@@ -172,8 +174,8 @@ static void frag_report(const char *filename)
                printf("%s: 1 extent found", filename);
        else
                printf("%s: %d extents found", filename, discont+1);
-       expected = (numblocks/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
-       if (is_ext2 && expected != discont+1)
+       expected = (count/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
+       if (is_ext2 && expected < discont+1)
                printf(", perfection would be %d extent%s\n", expected,
                        (expected>1) ? "s" : "");
        else