affs: 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-v1-9-6d3e4816aa7b@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/affs/dir.c b/fs/affs/dir.c
index b2bf7016e1b34655e3431e6f4fc2036c7491f9a2..bd40d5f0881042e7e6b15b09a76a1793169a1d50 100644 (file)
--- a/fs/affs/dir.c
+++ b/fs/affs/dir.c
@@ -17,13 +17,44 @@
 #include <linux/iversion.h>
 #include "affs.h"
 
+struct affs_dir_data {
+       unsigned long ino;
+       u64 cookie;
+};
+
 static int affs_readdir(struct file *, struct dir_context *);
 
+static loff_t affs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+       struct affs_dir_data *data = file->private_data;
+
+       return generic_llseek_cookie(file, offset, whence, &data->cookie);
+}
+
+static int affs_dir_open(struct inode *inode, struct file *file)
+{
+       struct affs_dir_data    *data;
+
+       data = kzalloc(sizeof(struct affs_dir_data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+       file->private_data = data;
+       return 0;
+}
+
+static int affs_dir_release(struct inode *inode, struct file *file)
+{
+       kfree(file->private_data);
+       return 0;
+}
+
 const struct file_operations affs_dir_operations = {
+       .open           = affs_dir_open,
        .read           = generic_read_dir,
-       .llseek         = generic_file_llseek,
+       .llseek         = affs_dir_llseek,
        .iterate_shared = affs_readdir,
        .fsync          = affs_file_fsync,
+       .release        = affs_dir_release,
 };
 
 /*
@@ -45,6 +76,7 @@ static int
 affs_readdir(struct file *file, struct dir_context *ctx)
 {
        struct inode            *inode = file_inode(file);
+       struct affs_dir_data    *data = file->private_data;
        struct super_block      *sb = inode->i_sb;
        struct buffer_head      *dir_bh = NULL;
        struct buffer_head      *fh_bh = NULL;
@@ -59,7 +91,7 @@ affs_readdir(struct file *file, struct dir_context *ctx)
        pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
 
        if (ctx->pos < 2) {
-               file->private_data = (void *)0;
+               data->ino = 0;
                if (!dir_emit_dots(file, ctx))
                        return 0;
        }
@@ -80,8 +112,8 @@ affs_readdir(struct file *file, struct dir_context *ctx)
        /* If the directory hasn't changed since the last call to readdir(),
         * we can jump directly to where we left off.
         */
-       ino = (u32)(long)file->private_data;
-       if (ino && inode_eq_iversion(inode, file->f_version)) {
+       ino = data->ino;
+       if (ino && inode_eq_iversion(inode, data->cookie)) {
                pr_debug("readdir() left off=%d\n", ino);
                goto inside;
        }
@@ -131,8 +163,8 @@ inside:
                } while (ino);
        }
 done:
-       file->f_version = inode_query_iversion(inode);
-       file->private_data = (void *)(long)ino;
+       data->cookie = inode_query_iversion(inode);
+       data->ino = ino;
        affs_brelse(fh_bh);
 
 out_brelse_dir: