Re: [PATCH] eal: fix plugindir processing to be filesystem agnostic

[Panu Matilainen <pmatilai@redhat.com>]

On 11/20/2015 06:38 PM, David Marchand wrote:
> Hello Panu,
>
> On Wed, Nov 18, 2015 at 7:45 AM, Panu Matilainen <pmatilai@redhat.com>
> wrote:
>
>> Not all filesystems supply struct dirent d_type field, in which case
>> everything in the specified directory would go ignored. One such
>> filesystem being XFS which RHEL 7 defaults to... stat() the entries
>> instead.
>>
>> Fixes: 9f8eb1d9ca0f ("eal: support driver loading from directory")
>>
>> Signed-off-by: Panu Matilainen <pmatilai@redhat.com>
>> ---
>>   lib/librte_eal/common/eal_common_options.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/librte_eal/common/eal_common_options.c
>> b/lib/librte_eal/common/eal_common_options.c
>> index bed7385..e51fa12 100644
>> --- a/lib/librte_eal/common/eal_common_options.c
>> +++ b/lib/librte_eal/common/eal_common_options.c
>> @@ -191,12 +191,14 @@ eal_plugindir_init(const char *path)
>>          }
>>
>>          while ((dent = readdir(d)) != NULL) {
>> -               if (dent->d_type != DT_REG && dent->d_type != DT_LNK)
>> -                       continue;
>> +               struct stat sb;
>>
>>                  snprintf(sopath, PATH_MAX-1, "%s/%s", path, dent->d_name);
>>                  sopath[PATH_MAX-1] = 0;
>>
>> +               if (!(stat(sopath, &sb) == 0 && S_ISREG(sb.st_mode)))
>> +                       continue;
>> +
>>                  if (eal_plugin_add(sopath) == -1)
>>                          break;
>>          }
>
>
>
> It looks like you would skip the symbolic links while you were not before.
> Intended ?

Intended. We want to accept symlinks in the driver directory, but the 
actual drivers are always regular files. Since stat() dereferences 
symbolic links it cannot return a file whose type would be S_IFLNK.

	- Panu -