linux-ext4 - [PATCH 2/9] udf: Avoid GFP_NOFS allocation in udf

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Date: Tue, 23 Jan 2024 16:25:01 +0100
From: Jan Kara <jack@...e.cz>
To: <linux-fsdevel@...r.kernel.org>
Cc: <linux-ext4@...r.kernel.org>,
	Matthew Wilcox <willy@...radead.org>,
	Jan Kara <jack@...e.cz>
Subject: [PATCH 2/9] udf: Avoid GFP_NOFS allocation in udf_symlink()

The GFP_NOFS allocation in udf_symlink() is called only under
inode->i_rwsem and UDF_I(inode)->i_data_sem. The first is safe wrt
reclaim, the second should be as well but allocating unde this lock is
actually unnecessary. Move the allocation from under i_data_sem and
change it to GFP_KERNEL.

Signed-off-by: Jan Kara <jack@...e.cz>
---
 fs/udf/namei.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 1f14a0621a91..1308109fd42d 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -566,7 +566,7 @@ static int udf_unlink(struct inode *dir, struct dentry *dentry)
 static int udf_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, const char *symname)
 {
-	struct inode *inode = udf_new_inode(dir, S_IFLNK | 0777);
+	struct inode *inode;
 	struct pathComponent *pc;
 	const char *compstart;
 	struct extent_position epos = {};
@@ -579,17 +579,20 @@ static int udf_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	struct udf_inode_info *iinfo;
 	struct super_block *sb = dir->i_sb;
 
-	if (IS_ERR(inode))
-		return PTR_ERR(inode);
-
-	iinfo = UDF_I(inode);
-	down_write(&iinfo->i_data_sem);
-	name = kmalloc(UDF_NAME_LEN_CS0, GFP_NOFS);
+	name = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL);
 	if (!name) {
 		err = -ENOMEM;
-		goto out_no_entry;
+		goto out;
+	}
+
+	inode = udf_new_inode(dir, S_IFLNK | 0777);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out;
 	}
 
+	iinfo = UDF_I(inode);
+	down_write(&iinfo->i_data_sem);
 	inode->i_data.a_ops = &udf_symlink_aops;
 	inode->i_op = &udf_symlink_inode_operations;
 	inode_nohighmem(inode);
-- 
2.35.3