New API: Bind the tune2fs command.

Previously we bound the 'tune2fs -l' command so that we could list out
the tunables of an ext2/3/4 filesystem.  Also commands like
set_e2label and set_e2uuid used tune2fs.

This commit binds many of the tunables that can be set using tune2fs.

The coverage is not complete, but we can add more later because this
uses optional parameters so the call is extensible without breaking
ABI.  The current change gives us enough for using libguestfs within
OpenStack.

1 files changed, 149 insertions, 0 deletions

diff --git a/daemon/ext2.c b/daemon/ext2.c
index f7889da4..79fd3549 100644
--- a/daemon/ext2.c
+++ b/daemon/ext2.c
@@ -32,6 +32,8 @@
 /* Confirmed this is true up to ext4 from the Linux sources. */
 #define EXT2_LABEL_MAX 16
 
+#define MAX_ARGS 64
+
 /* Choose which tools like mke2fs to use.  For RHEL 5 (only) there
  * is a special set of tools which support ext2/3/4.  eg. On RHEL 5,
  * mke2fs only supports ext2/3, but mke4fs supports ext2/3/4.
@@ -498,3 +500,150 @@ do_mke2fs_JU (const char *fstype, int blocksize, const char *device,
   free (err);
   return 0;
 }
+
+/* Takes optional arguments, consult optargs_bitmask. */
+int
+do_tune2fs (const char *device, /* only required parameter */
+            int force,
+            int maxmountcount,
+            int mountcount,
+            const char *errorbehavior,
+            int64_t group,
+            int intervalbetweenchecks,
+            int reservedblockspercentage,
+            const char *lastmounteddirectory,
+            int64_t reservedblockscount,
+            int64_t user)
+{
+  const char *argv[MAX_ARGS];
+  size_t i = 0;
+  int r;
+  char *err;
+  char prog[] = "tune2fs";
+  char maxmountcount_s[64];
+  char mountcount_s[64];
+  char group_s[64];
+  char intervalbetweenchecks_s[64];
+  char reservedblockspercentage_s[64];
+  char reservedblockscount_s[64];
+  char user_s[64];
+
+  if (e2prog (prog) == -1)
+    return -1;
+
+  ADD_ARG (argv, i, prog);
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_FORCE_BITMASK) {
+    if (force)
+      ADD_ARG (argv, i, "-f");
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_MAXMOUNTCOUNT_BITMASK) {
+    if (maxmountcount < 0) {
+      reply_with_error ("maxmountcount cannot be negative");
+      return -1;
+    }
+    ADD_ARG (argv, i, "-c");
+    snprintf (maxmountcount_s, sizeof maxmountcount_s, "%d", maxmountcount);
+    ADD_ARG (argv, i, maxmountcount_s);
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_MOUNTCOUNT_BITMASK) {
+    if (mountcount < 0) {
+      reply_with_error ("mountcount cannot be negative");
+      return -1;
+    }
+    ADD_ARG (argv, i, "-C");
+    snprintf (mountcount_s, sizeof mountcount_s, "%d", mountcount);
+    ADD_ARG (argv, i, mountcount_s);
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_ERRORBEHAVIOR_BITMASK) {
+    if (STRNEQ (errorbehavior, "continue") &&
+        STRNEQ (errorbehavior, "remount-ro") &&
+        STRNEQ (errorbehavior, "panic")) {
+      reply_with_error ("invalid errorbehavior parameter: %s", errorbehavior);
+      return -1;
+    }
+    ADD_ARG (argv, i, "-e");
+    ADD_ARG (argv, i, errorbehavior);
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_GROUP_BITMASK) {
+    if (group < 0) {
+      reply_with_error ("group cannot be negative");
+      return -1;
+    }
+    ADD_ARG (argv, i, "-g");
+    snprintf (group_s, sizeof group_s, "%" PRIi64, group);
+    ADD_ARG (argv, i, group_s);
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_INTERVALBETWEENCHECKS_BITMASK) {
+    if (intervalbetweenchecks < 0) {
+      reply_with_error ("intervalbetweenchecks cannot be negative");
+      return -1;
+    }
+    ADD_ARG (argv, i, "-i");
+    if (intervalbetweenchecks > 0) {
+      /* -i <NN>s is not documented in the man page, but has been
+       * supported in tune2fs for several years.
+       */
+      snprintf (intervalbetweenchecks_s, sizeof intervalbetweenchecks_s,
+                "%ds", intervalbetweenchecks);
+      ADD_ARG (argv, i, intervalbetweenchecks_s);
+    }
+    else
+      ADD_ARG (argv, i, "0");
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_RESERVEDBLOCKSPERCENTAGE_BITMASK) {
+    if (reservedblockspercentage < 0) {
+      reply_with_error ("reservedblockspercentage cannot be negative");
+      return -1;
+    }
+    ADD_ARG (argv, i, "-m");
+    snprintf (reservedblockspercentage_s, sizeof reservedblockspercentage_s,
+              "%d", reservedblockspercentage);
+    ADD_ARG (argv, i, reservedblockspercentage_s);
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_LASTMOUNTEDDIRECTORY_BITMASK) {
+    ADD_ARG (argv, i, "-M");
+    ADD_ARG (argv, i, lastmounteddirectory);
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_RESERVEDBLOCKSCOUNT_BITMASK) {
+    if (reservedblockscount < 0) {
+      reply_with_error ("reservedblockscount cannot be negative");
+      return -1;
+    }
+    ADD_ARG (argv, i, "-r");
+    snprintf (reservedblockscount_s, sizeof reservedblockscount_s,
+              "%" PRIi64, reservedblockscount);
+    ADD_ARG (argv, i, reservedblockscount_s);
+  }
+
+  if (optargs_bitmask & GUESTFS_TUNE2FS_USER_BITMASK) {
+    if (user < 0) {
+      reply_with_error ("user cannot be negative");
+      return -1;
+    }
+    ADD_ARG (argv, i, "-u");
+    snprintf (user_s, sizeof user_s, "%" PRIi64, user);
+    ADD_ARG (argv, i, user_s);
+  }
+
+  ADD_ARG (argv, i, device);
+  ADD_ARG (argv, i, NULL);
+
+  r = commandv (NULL, &err, argv);
+  if (r == -1) {
+    reply_with_error ("%s: %s: %s", prog, device, err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+  return 0;
+}