linux-kernel - [PATCH v2] f2fs: free_user_blocks should use reserved

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1502781273-97035-1-git-send-email-yunlong.song@huawei.com>
Date:   Tue, 15 Aug 2017 15:14:33 +0800
From:   Yunlong Song <yunlong.song@...wei.com>
To:     <jaegeuk@...nel.org>, <chao@...nel.org>, <yuchao0@...wei.com>,
        <yunlong.song@...oud.com>, <yunlong.song@...wei.com>
CC:     <miaoxie@...wei.com>, <bintian.wang@...wei.com>,
        <linux-fsdevel@...r.kernel.org>,
        <linux-f2fs-devel@...ts.sourceforge.net>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH v2] f2fs: free_user_blocks should use reserved_segments instead

The part (overprovision_segments - reserved_segments) can still be used for LFS
in some case, e.g., there are lots of invalid block from dirty segments, then
the part (overprovision_segments - reserved_segments) can be safely used. So
free_use_blocks should use reserved_segments instead, rather than directly use
overprovision_segments. BTW, we also add the constraint of sbi->reserved_blocks.

Signed-off-by: Yunlong Song <yunlong.song@...wei.com>
---
 fs/f2fs/gc.h | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 9325191..542612a 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -49,11 +49,23 @@ struct gc_inode_list {
  */
 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
 {
-	if (free_segments(sbi) < overprovision_segments(sbi))
+	block_t avail_user_block_count, free_blocks, avail_free_blocks;
+	block_t reserved_blocks;
+
+	avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks;
+
+	if (unlikely(sbi->total_valid_block_count > avail_user_block_count))
+		return 0;
+
+	free_blocks = free_segments(sbi) << sbi->log_blocks_per_seg;
+	avail_free_blocks = min(free_blocks, avail_user_block_count -
+								sbi->total_valid_block_count);
+	reserved_blocks = reserved_segments(sbi) << sbi->log_blocks_per_seg;
+
+	if (avail_free_blocks < reserved_blocks)
 		return 0;
 	else
-		return (free_segments(sbi) - overprovision_segments(sbi))
-			<< sbi->log_blocks_per_seg;
+		return avail_free_blocks - reserved_blocks;
 }
 
 static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
-- 
1.8.5.2