[RFC PATCH 5/8] f2fs: use fscrypt_prepare_new_inode() and fscrypt_set_context()

[Eric Biggers]

From: Eric Biggers <ebiggers at google.com>

Convert f2fs to use the new functions fscrypt_prepare_new_inode() and
fscrypt_set_context().  This avoids calling
fscrypt_get_encryption_info() from under f2fs_lock_op(), which can
deadlock because fscrypt_get_encryption_info() isn't GFP_NOFS-safe.

For more details about this problem, see the earlier patch
"fscrypt: add fscrypt_prepare_new_inode() and fscrypt_set_context()".

Signed-off-by: Eric Biggers <ebiggers at google.com>
---
 fs/f2fs/dir.c   |  2 +-
 fs/f2fs/f2fs.h  | 16 ----------------
 fs/f2fs/namei.c |  7 ++++++-
 3 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 069f498af1e38..d627ca97fc500 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -537,7 +537,7 @@ struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir,
 			goto put_error;
 
 		if (IS_ENCRYPTED(inode)) {
-			err = fscrypt_inherit_context(dir, inode, page, false);
+			err = fscrypt_set_context(inode, page);
 			if (err)
 				goto put_error;
 		}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 16322ea5b4630..eb37d1974ba8e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4022,22 +4022,6 @@ static inline bool f2fs_lfs_mode(struct f2fs_sb_info *sbi)
 	return F2FS_OPTION(sbi).fs_mode == FS_MODE_LFS;
 }
 
-static inline bool f2fs_may_encrypt(struct inode *dir, struct inode *inode)
-{
-#ifdef CONFIG_FS_ENCRYPTION
-	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
-	umode_t mode = inode->i_mode;
-
-	/*
-	 * If the directory encrypted or dummy encryption enabled,
-	 * then we should encrypt the inode.
-	 */
-	if (IS_ENCRYPTED(dir) || DUMMY_ENCRYPTION_ENABLED(sbi))
-		return (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode));
-#endif
-	return false;
-}
-
 static inline bool f2fs_may_compress(struct inode *inode)
 {
 	if (IS_SWAPFILE(inode) || f2fs_is_pinned_file(inode) ||
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 84e4bbc1a64de..45f324511a19e 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -28,6 +28,7 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
 	nid_t ino;
 	struct inode *inode;
 	bool nid_free = false;
+	bool encrypt = false;
 	int xattr_size = 0;
 	int err;
 
@@ -69,13 +70,17 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
 		F2FS_I(inode)->i_projid = make_kprojid(&init_user_ns,
 							F2FS_DEF_PROJID);
 
+	err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
+	if (err)
+		goto fail_drop;
+
 	err = dquot_initialize(inode);
 	if (err)
 		goto fail_drop;
 
 	set_inode_flag(inode, FI_NEW_INODE);
 
-	if (f2fs_may_encrypt(dir, inode))
+	if (encrypt)
 		f2fs_set_encrypted_inode(inode);
 
 	if (f2fs_sb_has_extra_attr(sbi)) {
-- 
2.28.0