Re: [PATCH] netfs: Let netfs depends on PROC_FS

[Song Liu <songliubraving@xxxxxxxx>]

Hi Paulo and David, 

> On Apr 8, 2025, at 8:05 AM, Paulo Alcantara <pc@xxxxxxxxxxxxx> wrote:
> 
> David Howells <dhowells@xxxxxxxxxx> writes:
> 
>> Paulo Alcantara <pc@xxxxxxxxxxxxx> wrote:
>> 
>>> (2) There's a wrong assumption in the API that @netfs_request_pool and
>>> @netfs_subrequest_pool will always be initialized.  For example, we
>>> should return an error from netfs_alloc_[sub]rquest() functions in case
>>> @mempool == NULL.
>> 
>> No.  The assumption is correct.  The problem is that if the module is built in
>> (ie. CONFIG_NETFS_SUPPORT=y), then there is no consequence of netfs_init()
>> failing - and fail it does if CONFIG_PROC_FS=n - and 9p, afs and cifs will
>> call into it anyway, despite the fact it deinitialised itself.
>> 
>> It should marked be module_init(), not fs_initcall().
> 
> Makes sense, thanks.  I tried to reproduce it with cifs.ko and it didn't
> oops as netfslib ended up not using the default memory pools as cifs.ko
> already provide its own memory pools via netfs_request_ops.

Thanks for the review. I guess we will need the following changes, 
probably in two separate patches?

Thanks,
Song


diff --git c/fs/netfs/main.c w/fs/netfs/main.c
index 4e3e62040831..e12f7575e657 100644
--- c/fs/netfs/main.c
+++ w/fs/netfs/main.c
@@ -127,11 +127,13 @@ static int __init netfs_init(void)
        if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0)
                goto error_subreqpool;

+#ifdef CONFIG_PROC_FS
        if (!proc_mkdir("fs/netfs", NULL))
                goto error_proc;
        if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL,
                             &netfs_requests_seq_ops))
                goto error_procfile;
+#endif
 #ifdef CONFIG_FSCACHE_STATS
        if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL,
                                netfs_stats_show))
@@ -157,7 +159,7 @@ static int __init netfs_init(void)
 error_req:
        return ret;
 }
-fs_initcall(netfs_init);
+module_init(netfs_init);

 static void __exit netfs_exit(void)
 {