e2fsprogs/e2fsck-clarify-overflow-link-count-error-message.patch

From 125850eb92f042c76b6f001bf63833ffc15e7916 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Thu, 13 Feb 2020 11:15:56 +0100
Subject: [PATCH] e2fsck: clarify overflow link count error message
References: bsc#1160979

When directory link count is set to overflow value (1) but during pass 4
we find out the exact link count would fit, we either silently fix this
(which is not great because e2fsck then reports the fs was modified but
output doesn't indicate why in any way), or we report that link count is
wrong and ask whether we should fix it (in case -n option was
specified). The second case is even more misleading because it suggests
non-trivial fs corruption which then gets silently fixed on the next
run. Similarly to how we fix up other non-problems, just create a new
error message for the case directory link count is not overflown anymore
and always report it to clarify what is going on.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
(cherry picked from commit 4ebce13292f54c96f43dcb1bd1d5b8df5dc8749d)
Acked-by: Jan Kara <jack@suse.cz>
---
 e2fsck/pass4.c   | 20 ++++++++++++++++----
 e2fsck/problem.c |  5 +++++
 e2fsck/problem.h |  3 +++
 3 files changed, 24 insertions(+), 4 deletions(-)

Index: e2fsprogs-1.43.8/e2fsck/pass4.c
===================================================================
--- e2fsprogs-1.43.8.orig/e2fsck/pass4.c
+++ e2fsprogs-1.43.8/e2fsck/pass4.c
@@ -169,6 +169,8 @@ void e2fsck_pass4(e2fsck_t ctx)
 		if (isdir && (link_counted > EXT2_LINK_MAX))
 			link_counted = 1;
 		if (link_counted != link_count) {
+			int fix_nlink = 0;
+
 			e2fsck_read_inode_full(ctx, i, EXT2_INODE(inode),
 					       inode_size, "pass4");
 			pctx.ino = i;
@@ -182,10 +184,20 @@ void e2fsck_pass4(e2fsck_t ctx)
 			pctx.num = link_counted;
 			/* i_link_count was previously exceeded, but no longer
 			 * is, fix this but don't consider it an error */
-			if ((isdir && link_counted > 1 &&
-			     (inode->i_flags & EXT2_INDEX_FL) &&
-			     link_count == 1 && !(ctx->options & E2F_OPT_NO)) ||
-			    fix_problem(ctx, PR_4_BAD_REF_COUNT, &pctx)) {
+			if (isdir && link_counted > 1 &&
+			    (inode->i_flags & EXT2_INDEX_FL) &&
+			    link_count == 1) {
+				if ((ctx->options & E2F_OPT_READONLY) == 0) {
+					fix_nlink =
+						fix_problem(ctx,
+							PR_4_DIR_OVERFLOW_REF_COUNT,
+							&pctx);
+				}
+			} else {
+				fix_nlink = fix_problem(ctx, PR_4_BAD_REF_COUNT,
+						&pctx);
+			}
+			if (fix_nlink) {
 				inode->i_links_count = link_counted;
 				e2fsck_write_inode_full(ctx, i,
 							EXT2_INODE(inode),
Index: e2fsprogs-1.43.8/e2fsck/problem.c
===================================================================
--- e2fsprogs-1.43.8.orig/e2fsck/problem.c
+++ e2fsprogs-1.43.8/e2fsck/problem.c
@@ -1857,6 +1857,11 @@ static struct e2fsck_problem problem_tab
 	  "They @s the same!\n"),
 	  PROMPT_NONE, 0 },
 
+	/* Directory inode ref count set to overflow but could be exact value */
+	{ PR_4_DIR_OVERFLOW_REF_COUNT,
+	  N_("@d @i %i ref count set to overflow but could be exact value %N.  "),
+	  PROMPT_FIX, PR_PREEN_OK, 0, 0, 0 },
+
 	/* Pass 5 errors */
 
 	/* Pass 5: Checking group summary information */
Index: e2fsprogs-1.43.8/e2fsck/problem.h
===================================================================
--- e2fsprogs-1.43.8.orig/e2fsck/problem.h
+++ e2fsprogs-1.43.8/e2fsck/problem.h
@@ -1123,6 +1123,9 @@ struct problem_context {
 /* Inconsistent inode count information cached */
 #define PR_4_INCONSISTENT_COUNT		0x040004
 
+/* Directory ref count set to overflow but it doesn't have to be */
+#define PR_4_DIR_OVERFLOW_REF_COUNT	0x040007
+
 /*
  * Pass 5 errors
  */