[PATCH 2/7] xfs_scrub: remove preen mode

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

While it's true that the kernel can tell us whether something needs
repairs or it needs optimizing, from the admin's perspective there's
no point in having an optimize-only mode -- either fix everything, or
don't.  This is what xfs_repair does w.r.t. -n, so let's do the same
thing too.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 man/man8/xfs_scrub.8 |   51 +++++++++++++++++++++++---------------------------
 scrub/phase1.c       |    6 +-----
 scrub/phase4.c       |   19 -------------------
 scrub/scrub.c        |    2 +-
 scrub/xfs_scrub.c    |   33 +++++++-------------------------
 scrub/xfs_scrub.h    |    3 ---
 6 files changed, 32 insertions(+), 82 deletions(-)


diff --git a/man/man8/xfs_scrub.8 b/man/man8/xfs_scrub.8
index 4c394a5..77fed92 100644
--- a/man/man8/xfs_scrub.8
+++ b/man/man8/xfs_scrub.8
@@ -1,10 +1,10 @@
 .TH xfs_scrub 8
 .SH NAME
-xfs_scrub \- scrub the contents of an XFS filesystem
+xfs_scrub \- check the contents of a mounted XFS filesystem
 .SH SYNOPSIS
 .B xfs_scrub
 [
-.B \-abCemnTvxy
+.B \-abCemnTvx
 ]
 .RI "[" mount-point " | " block-device "]"
 .br
@@ -13,6 +13,12 @@ xfs_scrub \- scrub the contents of an XFS filesystem
 .B xfs_scrub
 attempts to check and repair all metadata in a mounted XFS filesystem.
 .PP
+.B WARNING!
+This program is
+.BR EXPERIMENTAL ","
+which means that its behavior and interface
+could change at any time!
+.PP
 .B xfs_scrub
 asks the kernel to scrub all metadata objects in the filesystem.
 Metadata records are scanned for obviously bad values and then
@@ -28,19 +34,17 @@ the standard error stream.
 Enabling verbose mode will increase the amount of status information
 sent to the output.
 .PP
-This utility does not know how to correct all errors.
-If the tool cannot fix the detected errors, you must unmount the
-filesystem and run
+If the kernel scrub reports that metadata needs repairs or optimizations and
+the user does not pass
+.B -n
+on the command line, this program will ask the kernel to make the repairs and
+to perform the optimizations.
+See the sections about optimizations and repairs for a list of optimizations
+and repairs known to this program.
+The kernel may not support repairing or optimizing the filesystem.
+If this is the case, the filesystem must be unmounted and
 .BR xfs_repair (8)
-to fix the problems.
-If this tool is not run with either of the
-.B \-n
-or
-.B \-y
-options, then it will optimize the filesystem when possible,
-but it will not try to fix errors.
-See the optimizations section below for a list of optimizations
-supported by this program.
+run on the filesystem to fix the problems.
 .SH OPTIONS
 .TP
 .BI \-a " errors"
@@ -73,14 +77,14 @@ is given, no action is taken if errors are found; this is the default
 behavior.
 .TP
 .B \-k
-Do not call FITRIM on the free space.
+Do not call TRIM on the free space.
 .TP
 .BI \-m " file"
 Search this file for mounted filesystems instead of /etc/mtab.
 .TP
 .B \-n
-Dry run, do not modify anything in the filesystem.
-This disables all optimization and repair behaviors.
+Only check filesystem metadata.
+Do not repair or optimize anything.
 .TP
 .BI \-T
 Print timing and memory usage information for each phase.
@@ -98,20 +102,11 @@ will issue O_DIRECT reads to the block device directly.
 If the block device is a SCSI disk, it will instead issue READ VERIFY commands
 directly to the disk.
 These actions will confirm that all file data blocks can be read from storage.
-.TP
-.B \-y
-Try to repair all filesystem errors.
-If the errors cannot be fixed online, then the filesystem must be taken
-offline for repair.
 .SH OPTIMIZATIONS
-Optimizations supported by this program include:
+Optimizations supported by this program include, but are not limited to:
 .IP \[bu] 2
-Updating secondary superblocks to match the primary superblock.
-.IP \[bu]
-Turning off shared block write checks for files that no longer share blocks.
-.IP \[bu]
 Instructing the underlying storage to discard unused extents via the
-.B FITRIM
+.B TRIM
 ioctl.
 .SH REPAIRS
 This program currently does not support making any repairs.
diff --git a/scrub/phase1.c b/scrub/phase1.c
index 75da296..af93d0f 100644
--- a/scrub/phase1.c
+++ b/scrub/phase1.c
@@ -181,11 +181,7 @@ _("Kernel metadata scrubbing facility is not available."));
 
 	/* Do we need kernel-assisted metadata repair? */
 	if (ctx->mode != SCRUB_MODE_DRY_RUN && !xfs_can_repair(ctx)) {
-		if (ctx->mode == SCRUB_MODE_PREEN)
-			str_error(ctx, ctx->mntpoint,
-_("Kernel metadata optimization facility is not available.  Use -n to scrub."));
-		else
-			str_error(ctx, ctx->mntpoint,
+		str_error(ctx, ctx->mntpoint,
 _("Kernel metadata repair facility is not available.  Use -n to scrub."));
 		return false;
 	}
diff --git a/scrub/phase4.c b/scrub/phase4.c
index 3100d75..1fb8da9 100644
--- a/scrub/phase4.c
+++ b/scrub/phase4.c
@@ -62,25 +62,6 @@ xfs_repair_fs(
 	return xfs_process_action_items(ctx);
 }
 
-/* Run the optimize-only phase if there are no errors. */
-bool
-xfs_optimize_fs(
-	struct scrub_ctx	*ctx)
-{
-	/*
-	 * In preen mode, corruptions are immediately recorded as errors,
-	 * so if there are any corruptions on the filesystem errors_found
-	 * will be non-zero and we won't do anything.
-	 */
-	if (ctx->errors_found) {
-		str_info(ctx, ctx->mntpoint,
-_("Errors found, please re-run with -y."));
-		return true;
-	}
-
-	return xfs_process_action_items(ctx);
-}
-
 /* Estimate how much work we're going to do. */
 bool
 xfs_estimate_repair_work(
diff --git a/scrub/scrub.c b/scrub/scrub.c
index 6abca2a..bc0e2f0 100644
--- a/scrub/scrub.c
+++ b/scrub/scrub.c
@@ -279,7 +279,7 @@ _("Repairs are required."));
 	 * otherwise complain.
 	 */
 	if (is_unoptimized(meta)) {
-		if (ctx->mode < SCRUB_MODE_PREEN) {
+		if (ctx->mode != SCRUB_MODE_REPAIR) {
 			if (!is_inode) {
 				/* AG or FS metadata, always warn. */
 				str_info(ctx, buf,
diff --git a/scrub/xfs_scrub.c b/scrub/xfs_scrub.c
index 5ab557d..6efcf77 100644
--- a/scrub/xfs_scrub.c
+++ b/scrub/xfs_scrub.c
@@ -187,7 +187,6 @@ usage(void)
 	fprintf(stderr, _("  -v           Verbose output.\n"));
 	fprintf(stderr, _("  -V           Print version.\n"));
 	fprintf(stderr, _("  -x           Scrub file data too.\n"));
-	fprintf(stderr, _("  -y           Repair all errors.\n"));
 
 	exit(SCRUB_RET_SYNTAX);
 }
@@ -441,16 +440,11 @@ run_scrub_phases(
 		/* Turn on certain phases if user said to. */
 		if (sp->fn == DATASCAN_DUMMY_FN && scrub_data) {
 			sp->fn = xfs_scan_blocks;
-		} else if (sp->fn == REPAIR_DUMMY_FN) {
-			if (ctx->mode == SCRUB_MODE_PREEN) {
-				sp->descr = _("Optimize filesystem.");
-				sp->fn = xfs_optimize_fs;
-				sp->must_run = true;
-			} else if (ctx->mode == SCRUB_MODE_REPAIR) {
-				sp->descr = _("Repair filesystem.");
-				sp->fn = xfs_repair_fs;
-				sp->must_run = true;
-			}
+		} else if (sp->fn == REPAIR_DUMMY_FN &&
+			   ctx->mode == SCRUB_MODE_REPAIR) {
+			sp->descr = _("Repair filesystem.");
+			sp->fn = xfs_repair_fs;
+			sp->must_run = true;
 		}
 
 		/* Skip certain phases unless they're turned on. */
@@ -524,9 +518,9 @@ main(
 	textdomain(PACKAGE);
 
 	pthread_mutex_init(&ctx.lock, NULL);
-	ctx.mode = SCRUB_MODE_DEFAULT;
+	ctx.mode = SCRUB_MODE_REPAIR;
 	ctx.error_action = ERRORS_CONTINUE;
-	while ((c = getopt(argc, argv, "a:bC:de:km:nTvxVy")) != EOF) {
+	while ((c = getopt(argc, argv, "a:bC:de:km:nTvxV")) != EOF) {
 		switch (c) {
 		case 'a':
 			ctx.max_errors = cvt_u64(optarg, 10);
@@ -574,11 +568,6 @@ main(
 			mtab = optarg;
 			break;
 		case 'n':
-			if (ctx.mode != SCRUB_MODE_DEFAULT) {
-				fprintf(stderr,
-_("Only one of the options -n or -y may be specified.\n"));
-				usage();
-			}
 			ctx.mode = SCRUB_MODE_DRY_RUN;
 			break;
 		case 'T':
@@ -595,14 +584,6 @@ _("Only one of the options -n or -y may be specified.\n"));
 		case 'x':
 			scrub_data = true;
 			break;
-		case 'y':
-			if (ctx.mode != SCRUB_MODE_DEFAULT) {
-				fprintf(stderr,
-_("Only one of the options -n or -y may be specified.\n"));
-				usage();
-			}
-			ctx.mode = SCRUB_MODE_REPAIR;
-			break;
 		case '?':
 			/* fall through */
 		default:
diff --git a/scrub/xfs_scrub.h b/scrub/xfs_scrub.h
index 8407885..89b46a4 100644
--- a/scrub/xfs_scrub.h
+++ b/scrub/xfs_scrub.h
@@ -34,10 +34,8 @@ extern bool			stdout_isatty;
 
 enum scrub_mode {
 	SCRUB_MODE_DRY_RUN,
-	SCRUB_MODE_PREEN,
 	SCRUB_MODE_REPAIR,
 };
-#define SCRUB_MODE_DEFAULT			SCRUB_MODE_PREEN
 
 enum error_action {
 	ERRORS_CONTINUE,
@@ -111,7 +109,6 @@ bool xfs_scan_connections(struct scrub_ctx *ctx);
 bool xfs_scan_blocks(struct scrub_ctx *ctx);
 bool xfs_scan_summary(struct scrub_ctx *ctx);
 bool xfs_repair_fs(struct scrub_ctx *ctx);
-bool xfs_optimize_fs(struct scrub_ctx *ctx);
 
 /* Progress estimator functions */
 uint64_t xfs_estimate_inodes(struct scrub_ctx *ctx);