ufs: store cookie in private data

Store the cookie to detect concurrent seeks on directories in
file->private_data.

Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-16-6d3e4816aa7b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
index 61f25d3cf3f7149aec8cca53334d33fbf4649ea3..335f0ae529b4e8636a5d193c06d0c64c62da2fa6 100644 (file)
--- a/fs/ufs/dir.c
+++ b/fs/ufs/dir.c
@@ -435,7 +435,7 @@ ufs_readdir(struct file *file, struct dir_context *ctx)
        unsigned long n = pos >> PAGE_SHIFT;
        unsigned long npages = dir_pages(inode);
        unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
-       bool need_revalidate = !inode_eq_iversion(inode, file->f_version);
+       bool need_revalidate = !inode_eq_iversion(inode, *(u64 *)file->private_data);
        unsigned flags = UFS_SB(sb)->s_flags;
 
        UFSD("BEGIN\n");
@@ -462,7 +462,7 @@ ufs_readdir(struct file *file, struct dir_context *ctx)
                                offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
                                ctx->pos = (n<<PAGE_SHIFT) + offset;
                        }
-                       file->f_version = inode_query_iversion(inode);
+                       *(u64 *)file->private_data = inode_query_iversion(inode);
                        need_revalidate = false;
                }
                de = (struct ufs_dir_entry *)(kaddr+offset);
@@ -646,9 +646,31 @@ not_empty:
        return 0;
 }
 
+static int ufs_dir_open(struct inode *inode, struct file *file)
+{
+       file->private_data = kzalloc(sizeof(u64), GFP_KERNEL);
+       if (!file->private_data)
+               return -ENOMEM;
+       return 0;
+}
+
+static int ufs_dir_release(struct inode *inode, struct file *file)
+{
+       kfree(file->private_data);
+       return 0;
+}
+
+static loff_t ufs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+       return generic_llseek_cookie(file, offset, whence,
+                                    (u64 *)file->private_data);
+}
+
 const struct file_operations ufs_dir_operations = {
+       .open           = ufs_dir_open,
+       .release        = ufs_dir_release,
        .read           = generic_read_dir,
        .iterate_shared = ufs_readdir,
        .fsync          = generic_file_fsync,
-       .llseek         = generic_file_llseek,
+       .llseek         = ufs_dir_llseek,
 };