fstrim: add --dry-run

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/fstrim.8 b/sys-utils/fstrim.8
index eceaf272367981953282cd52b0e703655f0ec92b..f86dda984df51fd15f12217b84a81ffe92bf2da6 100644 (file)
--- a/sys-utils/fstrim.8
+++ b/sys-utils/fstrim.8
@@ -52,6 +52,8 @@ The other supplied options, like \fB\-\-offset\fR, \fB\-\-length\fR and
 \fB-\-minimum\fR, are applied to all these devices.
 Errors from filesystems that do not support the discard operation are silently
 ignored.
+.IP "\fB\-d, \-\-dry\-run\fP"
+This option does everything apart from actually call FITRIM ioctl.
 .IP "\fB\-o, \-\-offset\fP \fIoffset\fP"
 Byte offset in the filesystem from which to begin searching for free blocks
 to discard.  The default value is zero, starting at the beginning of the

diff --git a/sys-utils/fstrim.c b/sys-utils/fstrim.c
index 798811a22fb9218b42e86bcf53434a4d29fd6695..ad6084334079d3b333d8555a357954a8cd822d47 100644 (file)
--- a/sys-utils/fstrim.c
+++ b/sys-utils/fstrim.c
@@ -58,7 +58,7 @@ struct fstrim_range {
 
 /* returns: 0 = success, 1 = unsupported, < 0 = error */
 static int fstrim_filesystem(const char *path, struct fstrim_range *rangetpl,
-                           int verbose)
+                           int verbose, int dryrun)
 {
        int fd, rc;
        struct stat sb;
@@ -83,6 +83,13 @@ static int fstrim_filesystem(const char *path, struct fstrim_range *rangetpl,
                rc = -EINVAL;
                goto done;
        }
+
+       if (dryrun) {
+               printf(_("%s (dry run)\n"), path);
+               rc = 0;
+               goto done;
+       }
+
        errno = 0;
        if (ioctl(fd, FITRIM, &range)) {
                rc = errno == EOPNOTSUPP || errno == ENOTTY ? 1 : -errno;
@@ -188,7 +195,7 @@ static int uniq_fs_source_cmp(
  * 32 = all failed
  * 64 = some failed, some success
  */
-static int fstrim_all(struct fstrim_range *rangetpl, int verbose)
+static int fstrim_all(struct fstrim_range *rangetpl, int verbose, int dryrun)
 {
        struct libmnt_fs *fs;
        struct libmnt_iter *itr;
@@ -197,6 +204,7 @@ static int fstrim_all(struct fstrim_range *rangetpl, int verbose)
        int cnt = 0, cnt_err = 0;
 
        mnt_init_debug(0);
+       ul_path_init_debug();
 
        itr = mnt_new_iter(MNT_ITER_BACKWARD);
        if (!itr)
@@ -244,7 +252,7 @@ static int fstrim_all(struct fstrim_range *rangetpl, int verbose)
                 * This is reason why we ignore EOPNOTSUPP and ENOTTY errors
                 * from discard ioctl.
                 */
-               if (fstrim_filesystem(tgt, rangetpl, verbose) < 0)
+               if (fstrim_filesystem(tgt, rangetpl, verbose, dryrun) < 0)
                       cnt_err++;
        }
 
@@ -276,6 +284,7 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_(" -l, --length <num>  the number of bytes to discard\n"), out);
        fputs(_(" -m, --minimum <num> the minimum extent length to discard\n"), out);
        fputs(_(" -v, --verbose       print number of discarded bytes\n"), out);
+       fputs(_(" -d, --dry-run       does everything, but trim\n"), out);
 
        fputs(USAGE_SEPARATOR, out);
        printf(USAGE_HELP_OPTIONS(21));
@@ -286,7 +295,7 @@ static void __attribute__((__noreturn__)) usage(void)
 int main(int argc, char **argv)
 {
        char *path = NULL;
-       int c, rc, verbose = 0, all = 0;
+       int c, rc, verbose = 0, all = 0, dryrun = 0;
        struct fstrim_range range;
 
        static const struct option longopts[] = {
@@ -297,6 +306,7 @@ int main(int argc, char **argv)
            { "length",    required_argument, NULL, 'l' },
            { "minimum",   required_argument, NULL, 'm' },
            { "verbose",   no_argument,       NULL, 'v' },
+           { "dry-run",   no_argument,       NULL, 'd' },
            { NULL, 0, NULL, 0 }
        };
 
@@ -308,11 +318,14 @@ int main(int argc, char **argv)
        memset(&range, 0, sizeof(range));
        range.len = ULLONG_MAX;
 
-       while ((c = getopt_long(argc, argv, "ahVo:l:m:v", longopts, NULL)) != -1) {
+       while ((c = getopt_long(argc, argv, "adhVo:l:m:v", longopts, NULL)) != -1) {
                switch(c) {
                case 'a':
                        all = 1;
                        break;
+               case 'd':
+                       dryrun = 1;
+                       break;
                case 'h':
                        usage();
                        break;
@@ -352,9 +365,9 @@ int main(int argc, char **argv)
        }
 
        if (all)
-               return fstrim_all(&range, verbose);     /* MNT_EX_* codes */
+               return fstrim_all(&range, verbose, dryrun);     /* MNT_EX_* codes */
 
-       rc = fstrim_filesystem(path, &range, verbose);
+       rc = fstrim_filesystem(path, &range, verbose, dryrun);
        if (rc == 1)
                warnx(_("%s: the discard operation is not supported"), path);