Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
To:     Theodore Ts'o <tytso@mit.edu>
Cc:     linux-ext4@vger.kernel.org,
        Harshad Shirwadkar <harshadshirwadkar@gmail.com>,
        Wang Shilong <wshilong@ddn.com>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Li Xi <lixi@ddn.com>, Ritesh Harjani <ritesh.list@gmail.com>
Subject: [RFCv1 20/72] libext2fs: avoid too much memory allocation in case fs_num_threads
Date:   Mon,  7 Nov 2022 17:51:08 +0530
Message-Id: <5ae4498b906ea4adffcca5546e2c9deba39dd05a.1667822611.git.ritesh.list@gmail.com>
In-Reply-To: <cover.1667822611.git.ritesh.list@gmail.com>
References: <cover.1667822611.git.ritesh.list@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Wang Shilong <wshilong@ddn.com>

e2fsck init memory according to filesystem inodes/dir numbers
recorded in the superblock, this should be aware of filesystem
number of threads, otherwise, oom can happen.

So in case of fs->fs_num_threads, this patch controls the amount of
memory consumed for running multiple threads in e2fsck.

Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
---
 lib/ext2fs/dblist.c | 2 ++
 lib/ext2fs/icount.c | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/lib/ext2fs/dblist.c b/lib/ext2fs/dblist.c
index 5568b8ec..c19e17bc 100644
--- a/lib/ext2fs/dblist.c
+++ b/lib/ext2fs/dblist.c
@@ -58,6 +58,8 @@ static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size,
 		if (retval)
 			goto cleanup;
 		dblist->size = (num_dirs * 2) + 12;
+		if (fs->fs_num_threads)
+			dblist->size /= fs->fs_num_threads;
 	}
 	len = (size_t) sizeof(struct ext2_db_entry2) * dblist->size;
 	dblist->count = count;
diff --git a/lib/ext2fs/icount.c b/lib/ext2fs/icount.c
index 766eccca..48665c7e 100644
--- a/lib/ext2fs/icount.c
+++ b/lib/ext2fs/icount.c
@@ -237,6 +237,8 @@ errcode_t ext2fs_create_icount_tdb(ext2_filsys fs EXT2FS_NO_TDB_UNUSED,
 	 * value.
 	 */
 	num_inodes = fs->super->s_inodes_count - fs->super->s_free_inodes_count;
+	if (fs->fs_num_threads)
+		num_inodes /= fs->fs_num_threads;
 
 	icount->tdb = tdb_open(fn, num_inodes, TDB_NOLOCK | TDB_NOSYNC,
 			       O_RDWR | O_CREAT | O_TRUNC, 0600);
@@ -288,6 +290,8 @@ errcode_t ext2fs_create_icount2(ext2_filsys fs, int flags, unsigned int size,
 		if (retval)
 			goto errout;
 		icount->size += fs->super->s_inodes_count / 50;
+		if (fs->fs_num_threads)
+			icount->size /= fs->fs_num_threads;
 	}
 
 	bytes = (size_t) (icount->size * sizeof(struct ext2_icount_el));
-- 
2.37.3