Add support for FS_TRIM to user-mode UFS utilities.

Reviewed by:	mckusick, pjd, pho
Tested by:	pho
MFC after:	1 month

2 files changed, 50 insertions, 5 deletions

diff --git a/sbin/tunefs/tunefs.8 b/sbin/tunefs/tunefs.8
index a883cd4..a8904db 100644
--- a/sbin/tunefs/tunefs.8
+++ b/sbin/tunefs/tunefs.8
@@ -28,7 +28,7 @@
 .\"     @(#)tunefs.8	8.2 (Berkeley) 12/11/93
 .\" $FreeBSD$
 .\"
-.Dd March 6, 2010
+.Dd December 9, 2010
 .Dt TUNEFS 8
 .Os
 .Sh NAME
@@ -51,6 +51,7 @@
 .Op Fl p
 .Op Fl s Ar avgfpdir
 .Op Fl S Ar size
+.Op Fl t Cm enable | disable
 .Ar special | filesystem
 .Sh DESCRIPTION
 The
@@ -143,6 +144,14 @@ Specify the expected number of files per directory.
 .It Fl S Ar size
 Specify the softdep journal size in bytes.
 The minimum is 4M.
+.It Fl t Cm enable | disable
+Turn on/off the TRIM enable flag.
+If enabled, and if the underlying device supports the BIO_DELETE
+command, the file system will send a delete request to the underlying
+device for each freed block.
+The trim enable flag is typically set when the underlying device
+uses flash-memory as the device can use the delete command to
+pre-zero or at least avoid copying blocks that have been deleted.
 .El
 .Pp
 At least one of the above flags is required.
diff --git a/sbin/tunefs/tunefs.c b/sbin/tunefs/tunefs.c
index b2ea602..08c127d 100644
--- a/sbin/tunefs/tunefs.c
+++ b/sbin/tunefs/tunefs.c
@@ -82,11 +82,13 @@ int
 main(int argc, char *argv[])
 {
 	char *avalue, *jvalue, *Jvalue, *Lvalue, *lvalue, *Nvalue, *nvalue;
+	char *tvalue;
 	const char *special, *on;
 	const char *name;
 	int active;
 	int Aflag, aflag, eflag, evalue, fflag, fvalue, jflag, Jflag, Lflag;
 	int lflag, mflag, mvalue, Nflag, nflag, oflag, ovalue, pflag, sflag;
+	int tflag;
 	int svalue, Sflag, Svalue;
 	int ch, found_arg, i;
 	const char *chg[2];
@@ -96,12 +98,13 @@ main(int argc, char *argv[])
 	if (argc < 3)
 		usage();
 	Aflag = aflag = eflag = fflag = jflag = Jflag = Lflag = lflag = 0;
-	mflag = Nflag = nflag = oflag = pflag = sflag = 0;
+	mflag = Nflag = nflag = oflag = pflag = sflag = tflag = 0;
 	avalue = jvalue = Jvalue = Lvalue = lvalue = Nvalue = nvalue = NULL;
 	evalue = fvalue = mvalue = ovalue = svalue = Svalue = 0;
 	active = 0;
 	found_arg = 0;		/* At least one arg is required. */
-	while ((ch = getopt(argc, argv, "Aa:e:f:j:J:L:l:m:N:n:o:ps:S:")) != -1)
+	while ((ch = getopt(argc, argv, "Aa:e:f:j:J:L:l:m:N:n:o:ps:S:t:"))
+	    != -1)
 		switch (ch) {
 
 		case 'A':
@@ -268,6 +271,18 @@ main(int argc, char *argv[])
 			Sflag = 1;
 			break;
 
+		case 't':
+			found_arg = 1;
+			name = "trim";
+			tvalue = optarg;
+			if (strcmp(tvalue, "enable") != 0 &&
+			    strcmp(tvalue, "disable") != 0) {
+				errx(10, "bad %s (options are %s)",
+				    name, "`enable' or `disable'");
+			}
+			tflag = 1;
+			break;
+
 		default:
 			usage();
 		}
@@ -493,6 +508,24 @@ main(int argc, char *argv[])
 			sblock.fs_avgfpdir = svalue;
 		}
 	}
+	if (tflag) {
+		name = "issue TRIM to the disk";
+ 		if (strcmp(tvalue, "enable") == 0) {
+			if (sblock.fs_flags & FS_TRIM)
+				warnx("%s remains unchanged as enabled", name);
+			else {
+ 				sblock.fs_flags |= FS_TRIM;
+ 				warnx("%s set", name);
+			}
+ 		} else if (strcmp(tvalue, "disable") == 0) {
+			if ((~sblock.fs_flags & FS_TRIM) == FS_TRIM)
+				warnx("%s remains unchanged as disabled", name);
+			else {
+ 				sblock.fs_flags &= ~FS_TRIM;
+ 				warnx("%s cleared", name);
+			}
+ 		}
+	}
 
 	if (sbwrite(&disk, Aflag) == -1)
 		goto err;
@@ -1011,12 +1044,13 @@ out:
 void
 usage(void)
 {
-	fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n",
+	fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n",
 "usage: tunefs [-A] [-a enable | disable] [-e maxbpg] [-f avgfilesize]",
 "              [-J enable | disable] [-j enable | disable]", 
 "              [-L volname] [-l enable | disable] [-m minfree]",
 "              [-N enable | disable] [-n enable | disable]",
-"              [-o space | time] [-p] [-s avgfpdir] special | filesystem");
+"              [-o space | time] [-p] [-s avgfpdir] [-t enable | disable]",
+"              special | filesystem");
 	exit(2);
 }
 
@@ -1035,6 +1069,8 @@ printfs(void)
 		(sblock.fs_flags & FS_SUJ)? "enabled" : "disabled");
 	warnx("gjournal: (-J)                                     %s",
 		(sblock.fs_flags & FS_GJOURNAL)? "enabled" : "disabled");
+	warnx("trim: (-t)                                         %s", 
+		(sblock.fs_flags & FS_TRIM)? "enabled" : "disabled");
 	warnx("maximum blocks per file in a cylinder group: (-e)  %d",
 	      sblock.fs_maxbpg);
 	warnx("average file size: (-f)                            %d",