linux-kernel - [PATCH] f2fs: handle error cases of memory donation

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-next>] [day] [month] [year] [list]

Message-ID: <20250422191128.1346260-1-daeho43@gmail.com>
Date: Tue, 22 Apr 2025 12:11:28 -0700
From: Daeho Jeong <daeho43@...il.com>
To: linux-kernel@...r.kernel.org,
	linux-f2fs-devel@...ts.sourceforge.net,
	kernel-team@...roid.com
Cc: Daeho Jeong <daehojeong@...gle.com>
Subject: [PATCH] f2fs: handle error cases of memory donation

From: Daeho Jeong <daehojeong@...gle.com>

In cases of removing memory donation, we need to handle some error cases
like ENOENT and EACCES (indicating the range already has been donated).

Signed-off-by: Daeho Jeong <daehojeong@...gle.com>
---
 fs/f2fs/f2fs.h     |  1 +
 fs/f2fs/file.c     | 21 ++++++++++++++-------
 fs/f2fs/shrinker.c |  5 +++++
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f1576dc6ec67..e4b39550f380 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -821,6 +821,7 @@ enum {
 	FI_ATOMIC_DIRTIED,	/* indicate atomic file is dirtied */
 	FI_ATOMIC_REPLACE,	/* indicate atomic replace */
 	FI_OPENED_FILE,		/* indicate file has been opened */
+	FI_PAGE_DONATED,	/* indicate pages of file has been donated */
 	FI_MAX,			/* max flag, never be used */
 };
 
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index abbcbb5865a3..0807f8e97492 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2464,19 +2464,20 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
 	return ret;
 }
 
-static void f2fs_keep_noreuse_range(struct inode *inode,
+static int f2fs_keep_noreuse_range(struct inode *inode,
 				loff_t offset, loff_t len)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	u64 max_bytes = F2FS_BLK_TO_BYTES(max_file_blocks(inode));
 	u64 start, end;
+	int ret = 0;
 
 	if (!S_ISREG(inode->i_mode))
-		return;
+		return 0;
 
 	if (offset >= max_bytes || len > max_bytes ||
 	    (offset + len) > max_bytes)
-		return;
+		return 0;
 
 	start = offset >> PAGE_SHIFT;
 	end = DIV_ROUND_UP(offset + len, PAGE_SIZE);
@@ -2484,7 +2485,7 @@ static void f2fs_keep_noreuse_range(struct inode *inode,
 	inode_lock(inode);
 	if (f2fs_is_atomic_file(inode)) {
 		inode_unlock(inode);
-		return;
+		return 0;
 	}
 
 	spin_lock(&sbi->inode_lock[DONATE_INODE]);
@@ -2493,7 +2494,10 @@ static void f2fs_keep_noreuse_range(struct inode *inode,
 		if (!list_empty(&F2FS_I(inode)->gdonate_list)) {
 			list_del_init(&F2FS_I(inode)->gdonate_list);
 			sbi->donate_files--;
-		}
+			if (is_inode_flag_set(inode, FI_PAGE_DONATED))
+				ret = -EACCES;
+		} else
+			ret = -ENOENT;
 	} else {
 		if (list_empty(&F2FS_I(inode)->gdonate_list)) {
 			list_add_tail(&F2FS_I(inode)->gdonate_list,
@@ -2505,9 +2509,12 @@ static void f2fs_keep_noreuse_range(struct inode *inode,
 		}
 		F2FS_I(inode)->donate_start = start;
 		F2FS_I(inode)->donate_end = end - 1;
+		clear_inode_flag(inode, FI_PAGE_DONATED);
 	}
 	spin_unlock(&sbi->inode_lock[DONATE_INODE]);
 	inode_unlock(inode);
+
+	return ret;
 }
 
 static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
@@ -5236,8 +5243,8 @@ static int f2fs_file_fadvise(struct file *filp, loff_t offset, loff_t len,
 	     f2fs_compressed_file(inode)))
 		f2fs_invalidate_compress_pages(F2FS_I_SB(inode), inode->i_ino);
 	else if (advice == POSIX_FADV_NOREUSE)
-		f2fs_keep_noreuse_range(inode, offset, len);
-	return 0;
+		err = f2fs_keep_noreuse_range(inode, offset, len);
+	return err;
 }
 
 #ifdef CONFIG_COMPAT
diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index 9c8d3aee89af..1fa6619db40f 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -186,8 +186,13 @@ static unsigned int do_reclaim_caches(struct f2fs_sb_info *sbi,
 
 		len = fi->donate_end - fi->donate_start + 1;
 		npages = npages < len ? 0 : npages - len;
+
+		inode_lock(inode);
 		invalidate_inode_pages2_range(inode->i_mapping,
 					fi->donate_start, fi->donate_end);
+		set_inode_flag(inode, FI_PAGE_DONATED);
+		inode_unlock(inode);
+
 		iput(inode);
 		cond_resched();
 	}
-- 
2.49.0.805.g082f7c87e0-goog