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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Chao Yu <yuchao0@huawei.com>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.11 122/329] f2fs: fix to align to section for fallocate() on pinned file
Date:   Mon, 17 May 2021 16:00:33 +0200
Message-Id: <20210517140306.238770756@linuxfoundation.org>
In-Reply-To: <20210517140302.043055203@linuxfoundation.org>
References: <20210517140302.043055203@linuxfoundation.org>
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From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit e1175f02291141bbd924fc578299305fcde35855 ]

Now, fallocate() on a pinned file only allocates blocks which aligns
to segment rather than section, so GC may try to migrate pinned file's
block, and after several times of failure, pinned file's block could
be migrated to other place, however user won't be aware of such
condition, and then old obsolete block address may be readed/written
incorrectly.

To avoid such condition, let's try to allocate pinned file's blocks
with section alignment.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/f2fs.h    |  2 +-
 fs/f2fs/file.c    | 19 +++++++++----------
 fs/f2fs/segment.c | 34 ++++++++++++++++++++++++++--------
 3 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a150633400ed..e72ed7baf17f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3329,7 +3329,7 @@ void f2fs_get_new_segment(struct f2fs_sb_info *sbi,
 			unsigned int *newseg, bool new_sec, int dir);
 void f2fs_allocate_segment_for_resize(struct f2fs_sb_info *sbi, int type,
 					unsigned int start, unsigned int end);
-void f2fs_allocate_new_segment(struct f2fs_sb_info *sbi, int type);
+void f2fs_allocate_new_section(struct f2fs_sb_info *sbi, int type);
 void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi);
 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range);
 bool f2fs_exist_trim_candidates(struct f2fs_sb_info *sbi,
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 2af0f0e292d5..00e89f45ccde 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1643,27 +1643,26 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
 		return 0;
 
 	if (f2fs_is_pinned_file(inode)) {
-		block_t len = (map.m_len >> sbi->log_blocks_per_seg) <<
-					sbi->log_blocks_per_seg;
+		block_t sec_blks = BLKS_PER_SEC(sbi);
+		block_t sec_len = roundup(map.m_len, sec_blks);
 		block_t done = 0;
 
-		if (map.m_len % sbi->blocks_per_seg)
-			len += sbi->blocks_per_seg;
-
-		map.m_len = sbi->blocks_per_seg;
+		map.m_len = sec_blks;
 next_alloc:
 		if (has_not_enough_free_secs(sbi, 0,
 			GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
 			down_write(&sbi->gc_lock);
 			err = f2fs_gc(sbi, true, false, false, NULL_SEGNO);
-			if (err && err != -ENODATA && err != -EAGAIN)
+			if (err && err != -ENODATA && err != -EAGAIN) {
+				map.m_len = done;
 				goto out_err;
+			}
 		}
 
 		down_write(&sbi->pin_sem);
 
 		f2fs_lock_op(sbi);
-		f2fs_allocate_new_segment(sbi, CURSEG_COLD_DATA_PINNED);
+		f2fs_allocate_new_section(sbi, CURSEG_COLD_DATA_PINNED);
 		f2fs_unlock_op(sbi);
 
 		map.m_seg_type = CURSEG_COLD_DATA_PINNED;
@@ -1672,9 +1671,9 @@ next_alloc:
 		up_write(&sbi->pin_sem);
 
 		done += map.m_len;
-		len -= map.m_len;
+		sec_len -= map.m_len;
 		map.m_lblk += map.m_len;
-		if (!err && len)
+		if (!err && sec_len)
 			goto next_alloc;
 
 		map.m_len = done;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index f447fcbff5bb..86bbba93c349 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2910,7 +2910,8 @@ unlock:
 	up_read(&SM_I(sbi)->curseg_lock);
 }
 
-static void __allocate_new_segment(struct f2fs_sb_info *sbi, int type)
+static void __allocate_new_segment(struct f2fs_sb_info *sbi, int type,
+								bool new_sec)
 {
 	struct curseg_info *curseg = CURSEG_I(sbi, type);
 	unsigned int old_segno;
@@ -2918,10 +2919,22 @@ static void __allocate_new_segment(struct f2fs_sb_info *sbi, int type)
 	if (!curseg->inited)
 		goto alloc;
 
-	if (!curseg->next_blkoff &&
-		!get_valid_blocks(sbi, curseg->segno, false) &&
-		!get_ckpt_valid_blocks(sbi, curseg->segno))
-		return;
+	if (curseg->next_blkoff ||
+		get_valid_blocks(sbi, curseg->segno, new_sec))
+		goto alloc;
+
+	if (new_sec) {
+		unsigned int segno = START_SEGNO(curseg->segno);
+		int i;
+
+		for (i = 0; i < sbi->segs_per_sec; i++, segno++) {
+			if (get_ckpt_valid_blocks(sbi, segno))
+				goto alloc;
+		}
+	} else {
+		if (!get_ckpt_valid_blocks(sbi, curseg->segno))
+			return;
+	}
 
 alloc:
 	old_segno = curseg->segno;
@@ -2929,10 +2942,15 @@ alloc:
 	locate_dirty_segment(sbi, old_segno);
 }
 
-void f2fs_allocate_new_segment(struct f2fs_sb_info *sbi, int type)
+static void __allocate_new_section(struct f2fs_sb_info *sbi, int type)
+{
+	__allocate_new_segment(sbi, type, true);
+}
+
+void f2fs_allocate_new_section(struct f2fs_sb_info *sbi, int type)
 {
 	down_write(&SIT_I(sbi)->sentry_lock);
-	__allocate_new_segment(sbi, type);
+	__allocate_new_section(sbi, type);
 	up_write(&SIT_I(sbi)->sentry_lock);
 }
 
@@ -2942,7 +2960,7 @@ void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi)
 
 	down_write(&SIT_I(sbi)->sentry_lock);
 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++)
-		__allocate_new_segment(sbi, i);
+		__allocate_new_segment(sbi, i, false);
 	up_write(&SIT_I(sbi)->sentry_lock);
 }
 
-- 
2.30.2