From 334cc898f177771a5f1ca14c181d6df775cc55ec Mon Sep 17 00:00:00 2001

From: Jan Kara <jack@suse.cz>

Date: Thu, 13 Feb 2020 11:15:56 +0100

Subject: [PATCH 7/7] e2fsck: clarify overflow link count error message

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.

RHBZ: 1820048

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)

---

 e2fsck/pass4.c   | 19 +++++++++++++++----

 e2fsck/problem.c |  5 +++++

 e2fsck/problem.h |  3 +++

 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/e2fsck/pass4.c b/e2fsck/pass4.c

index ad95227c..c9586dfb 100644

--- a/e2fsck/pass4.c

+++ b/e2fsck/pass4.c

@@ -173,6 +173,7 @@ void e2fsck_pass4(e2fsck_t ctx)

 			link_counted = 1;

 		}

 		if (link_counted != link_count) {

+			int fix_nlink = 0;

 			e2fsck_read_inode(ctx, i, inode, "pass4");

 			pctx.ino = i;

 			pctx.inode = inode;

@@ -185,10 +186,20 @@ 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(ctx, i, inode, "pass4");

 			}

diff --git a/e2fsck/problem.c b/e2fsck/problem.c

index 0210ff8f..2e41bb2e 100644

--- a/e2fsck/problem.c

+++ b/e2fsck/problem.c

@@ -1581,6 +1581,11 @@ static struct e2fsck_problem problem_table[] = {

 	  N_("@d exceeds max links, but no DIR_NLINK feature in @S.\n"),

 	  PROMPT_FIX, 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 */

diff --git a/e2fsck/problem.h b/e2fsck/problem.h

index 5712de59..a591974e 100644

--- a/e2fsck/problem.h

+++ b/e2fsck/problem.h

@@ -948,6 +948,9 @@ 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

  */

-- 

2.21.1