Hi Catalin,
On 07/31/2017 07:19 AM, Catalin Marinas wrote:
> Anna, Trond,
>
> On Fri, Jul 28, 2017 at 06:54:52PM +0100, Catalin Marinas wrote:
>> --- a/fs/nfs/nfs4proc.c
>> +++ b/fs/nfs/nfs4proc.c
>> @@ -2236,7 +2236,7 @@ static int nfs4_opendata_access(struct rpc_cred *cred,
>> int openflags)
>> {
>> struct nfs_access_entry cache;
>> - u32 mask;
>> + int mask, cache_mask;
>>
>> /* access call failed or for some reason the server doesn't
>> * support any access modes -- defer access call until later */
>> @@ -2259,7 +2259,8 @@ static int nfs4_opendata_access(struct rpc_cred *cred,
>> nfs_access_set_mask(&cache, opendata->o_res.access_result);
>> nfs_access_add_cache(state->inode, &cache);
>>
>> - if ((mask & ~cache.mask & (MAY_READ | MAY_EXEC)) == 0)
>> + cache_mask = nfs_access_calc_mask(cache.mask, state->inode->i_mode);
>> + if ((mask & ~cache_mask & (MAY_READ | MAY_EXEC)) == 0)
>> return 0;
>>
>> return -EACCES;
>
> I noticed -rc3 already has a fix here, commit 1e6f209515a0 ("NFS: Use
> raw NFS access mask in nfs4_opendata_access()"), without having to
> export nfs_access_calc_mask().
>
>> @@ -3870,25 +3871,9 @@ static int _nfs4_proc_access(struct inode *inode,
>> struct nfs_access_entry *entry
>> .rpc_resp = &res,
>> .rpc_cred = entry->cred,
>> };
>> - int mode = entry->mask;
>> int status = 0;
>>
>> - /*
>> - * Determine which access bits we want to ask for...
>> - */
>> - if (mode & MAY_READ)
>> - args.access |= NFS4_ACCESS_READ;
>> - if (S_ISDIR(inode->i_mode)) {
>> - if (mode & MAY_WRITE)
>> - args.access |= NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND
>> | NFS4_ACCESS_DELETE;
>> - if (mode & MAY_EXEC)
>> - args.access |= NFS4_ACCESS_LOOKUP;
>> - } else {
>> - if (mode & MAY_WRITE)
>> - args.access |= NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND;
>> - if (mode & MAY_EXEC)
>> - args.access |= NFS4_ACCESS_EXECUTE;
>> - }
>> + args.access = entry->mask;
>
> However, AFAICT, 'entry->mask' already uses the NFS4_* bits, so checking
> 'mode' against MAY_READ etc. to build up args.access is incorrect. Is
> this hunk still needed?
>
I think the code is okay short term, because all the bits it's checking against
are set in entry->mask whenever we enter this function. Long term, yes it
should be updated. I have patches to do this in a generic way that can be used
for both NFS v3 and NFS v4, but they'll probably go into 4.14
Thanks,
Anna
