ext4: Use page_symlink() instead of __page_symlink()

By using the memalloc_nofs_save() functionality, we can call
page_symlink(), safe in the knowledge that it won't recurse into the
filesystem.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 767b4bfe39c38974fb90767ad2bbcf3d0638d345..1e7c5deed5e30faf1c2c51ddfd229b6ff95925be 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -29,6 +29,7 @@
 #include <linux/pagemap.h>
 #include <linux/time.h>
 #include <linux/fcntl.h>
+#include <linux/sched/mm.h>
 #include <linux/stat.h>
 #include <linux/string.h>
 #include <linux/quotaops.h>
@@ -3308,6 +3309,8 @@ static int ext4_symlink(struct user_namespace *mnt_userns, struct inode *dir,
        }
 
        if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
+               unsigned int flags;
+
                if (!IS_ENCRYPTED(inode))
                        inode->i_op = &ext4_symlink_inode_operations;
                inode_nohighmem(inode);
@@ -3329,7 +3332,9 @@ static int ext4_symlink(struct user_namespace *mnt_userns, struct inode *dir,
                handle = NULL;
                if (err)
                        goto err_drop_inode;
-               err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
+               flags = memalloc_nofs_save();
+               err = page_symlink(inode, disk_link.name, disk_link.len);
+               memalloc_nofs_restore(flags);
                if (err)
                        goto err_drop_inode;
                /*