linux-kernel - [PATCH AUTOSEL 5.4 248/266] f2fs: don't return vmalloc() memory from f2fs

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Message-Id: <20200618011631.604574-248-sashal@kernel.org>
Date:   Wed, 17 Jun 2020 21:16:13 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Eric Biggers <ebiggers@...gle.com>, Chao Yu <yuchao0@...wei.com>,
        Jaegeuk Kim <jaegeuk@...nel.org>,
        Sasha Levin <sashal@...nel.org>,
        linux-f2fs-devel@...ts.sourceforge.net
Subject: [PATCH AUTOSEL 5.4 248/266] f2fs: don't return vmalloc() memory from f2fs_kmalloc()

From: Eric Biggers <ebiggers@...gle.com>

[ Upstream commit 0b6d4ca04a86b9dababbb76e58d33c437e127b77 ]

kmalloc() returns kmalloc'ed memory, and kvmalloc() returns either
kmalloc'ed or vmalloc'ed memory.  But the f2fs wrappers, f2fs_kmalloc()
and f2fs_kvmalloc(), both return both kinds of memory.

It's redundant to have two functions that do the same thing, and also
breaking the standard naming convention is causing bugs since people
assume it's safe to kfree() memory allocated by f2fs_kmalloc().  See
e.g. the various allocations in fs/f2fs/compress.c.

Fix this by making f2fs_kmalloc() just use kmalloc().  And to avoid
re-introducing the allocation failures that the vmalloc fallback was
intended to fix, convert the largest allocations to use f2fs_kvmalloc().

Signed-off-by: Eric Biggers <ebiggers@...gle.com>
Reviewed-by: Chao Yu <yuchao0@...wei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/f2fs/checkpoint.c | 4 ++--
 fs/f2fs/f2fs.h       | 8 +-------
 fs/f2fs/node.c       | 8 ++++----
 fs/f2fs/super.c      | 2 +-
 4 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index a28ffecc0f95..bbd07fe8a492 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -892,8 +892,8 @@ int f2fs_get_valid_checkpoint(struct f2fs_sb_info *sbi)
 	int i;
 	int err;
 
-	sbi->ckpt = f2fs_kzalloc(sbi, array_size(blk_size, cp_blks),
-				 GFP_KERNEL);
+	sbi->ckpt = f2fs_kvzalloc(sbi, array_size(blk_size, cp_blks),
+				  GFP_KERNEL);
 	if (!sbi->ckpt)
 		return -ENOMEM;
 	/*
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 3edde3d6d089..3c7a4df5cdf0 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2789,18 +2789,12 @@ static inline bool f2fs_may_extent_tree(struct inode *inode)
 static inline void *f2fs_kmalloc(struct f2fs_sb_info *sbi,
 					size_t size, gfp_t flags)
 {
-	void *ret;
-
 	if (time_to_inject(sbi, FAULT_KMALLOC)) {
 		f2fs_show_injection_info(FAULT_KMALLOC);
 		return NULL;
 	}
 
-	ret = kmalloc(size, flags);
-	if (ret)
-		return ret;
-
-	return kvmalloc(size, flags);
+	return kmalloc(size, flags);
 }
 
 static inline void *f2fs_kzalloc(struct f2fs_sb_info *sbi,
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index f14401a77d60..90a20bd12961 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -2933,7 +2933,7 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
 		return 0;
 
 	nm_i->nat_bits_blocks = F2FS_BLK_ALIGN((nat_bits_bytes << 1) + 8);
-	nm_i->nat_bits = f2fs_kzalloc(sbi,
+	nm_i->nat_bits = f2fs_kvzalloc(sbi,
 			nm_i->nat_bits_blocks << F2FS_BLKSIZE_BITS, GFP_KERNEL);
 	if (!nm_i->nat_bits)
 		return -ENOMEM;
@@ -3066,9 +3066,9 @@ static int init_free_nid_cache(struct f2fs_sb_info *sbi)
 	int i;
 
 	nm_i->free_nid_bitmap =
-		f2fs_kzalloc(sbi, array_size(sizeof(unsigned char *),
-					     nm_i->nat_blocks),
-			     GFP_KERNEL);
+		f2fs_kvzalloc(sbi, array_size(sizeof(unsigned char *),
+					      nm_i->nat_blocks),
+			      GFP_KERNEL);
 	if (!nm_i->free_nid_bitmap)
 		return -ENOMEM;
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 47bfa5f2b75d..b530db25f2f2 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2889,7 +2889,7 @@ static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
 	if (nr_sectors & (bdev_zone_sectors(bdev) - 1))
 		FDEV(devi).nr_blkz++;
 
-	FDEV(devi).blkz_seq = f2fs_kzalloc(sbi,
+	FDEV(devi).blkz_seq = f2fs_kvzalloc(sbi,
 					BITS_TO_LONGS(FDEV(devi).nr_blkz)
 					* sizeof(unsigned long),
 					GFP_KERNEL);
-- 
2.25.1