e2fsck: check for invalid quota inode numbers

If the superblock has invalid inode numbers for the user, group, or
project quota inodes, e2fsck should notice and offer to fix things by
zeroing out the invalid superblock field.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

e2fsck/e2fsck.h

@@ -505,6 +505,7 @@ extern void set_up_logging(e2fsck_t ctx);
 
 /* quota.c */
 extern void e2fsck_hide_quota(e2fsck_t ctx);
+extern void e2fsck_validate_quota_inodes(e2fsck_t ctx);
 
 /* pass1.c */
 extern errcode_t e2fsck_setup_icount(e2fsck_t ctx, const char *icount_name,

e2fsck/problem.c

@@ -488,6 +488,11 @@ static struct e2fsck_problem problem_table[] = {
 	  N_("Bad desired extra isize in @S (%N).  "),
 	  PROMPT_FIX, 0 },
 
+	/* Invalid quota inode number */
+	{ PR_0_INVALID_QUOTA_INO,
+	  N_("Invalid %U @q @i %i.  "),
+	  PROMPT_FIX, 0 },
+
 	/* Pass 1 errors */
 
 	/* Pass 1: Checking inodes, blocks, and sizes */

e2fsck/problem.h

@@ -279,6 +279,9 @@ struct problem_context {
 /* Bad desired extra isize in superblock */
 #define PR_0_BAD_WANT_EXTRA_ISIZE		0x00004E
 
+/* Invalid quota inode number */
+#define PR_0_INVALID_QUOTA_INO			0x00004F
+
 
 /*
  * Pass 1 errors

e2fsck/quota.c

@@ -79,8 +79,39 @@ void e2fsck_hide_quota(e2fsck_t ctx)
 		    fix_problem(ctx, PR_0_HIDE_QUOTA, &pctx)) {
 			move_quota_inode(fs, pctx.ino, quota_ino, qtype);
 			*quota_sb_inump(sb, qtype) = quota_ino;
+			ext2fs_mark_super_dirty(fs);
 		}
 	}
 
 	return;
 }
+
+void e2fsck_validate_quota_inodes(e2fsck_t ctx)
+{
+	struct ext2_super_block *sb = ctx->fs->super;
+	struct problem_context	pctx;
+	ext2_filsys		fs = ctx->fs;
+	enum quota_type qtype;
+	ext2_ino_t quota_ino;
+
+	clear_problem_context(&pctx);
+
+	for (qtype = 0; qtype < MAXQUOTAS; qtype++) {
+		pctx.ino = *quota_sb_inump(sb, qtype);
+		pctx.num = qtype;
+		if (pctx.ino &&
+		    ((pctx.ino == EXT2_BAD_INO) ||
+		     (pctx.ino == EXT2_ROOT_INO) ||
+		     (pctx.ino == EXT2_BOOT_LOADER_INO) ||
+		     (pctx.ino == EXT2_UNDEL_DIR_INO) ||
+		     (pctx.ino == EXT2_RESIZE_INO) ||
+		     (pctx.ino == EXT2_JOURNAL_INO) ||
+		     (pctx.ino == EXT2_EXCLUDE_INO) ||
+		     (pctx.ino == EXT4_REPLICA_INO) ||
+		     (pctx.ino > fs->super->s_inodes_count)) &&
+		    fix_problem(ctx, PR_0_INVALID_QUOTA_INO, &pctx)) {
+			*quota_sb_inump(sb, qtype) = 0;
+			ext2fs_mark_super_dirty(fs);
+		}
+	}
+}

e2fsck/super.c

@@ -910,6 +910,8 @@ void check_super_block(e2fsck_t ctx)
 		}
 	}
 
+	e2fsck_validate_quota_inodes(ctx);
+
 	/*
 	 * Move the ext3 journal file, if necessary.
 	 */

tests/f_quota_invalid_inum/expect.1

@@ -0,0 +1,15 @@
+Invalid user quota inode 808464432.  Fix? yes
+
+Invalid group quota inode 808464432.  Fix? yes
+
+Invalid group quota inode 808464432.  Fix? yes
+
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 11/16 files (0.0% non-contiguous), 21/100 blocks
+Exit status is 1

tests/f_quota_invalid_inum/expect.2

@@ -0,0 +1,7 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 11/16 files (0.0% non-contiguous), 21/100 blocks
+Exit status is 0

tests/f_quota_invalid_inum/name

@@ -0,0 +1 @@
+invalid quota inode numbers