Re: [PATCH] cifs: handle cifs_get_tcon() errors properly

[Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org>]

On 11/15/2010 06:55 PM, Jeff Layton wrote:
> On Mon, 15 Nov 2010 18:15:23 +0530
> Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org> wrote:
> 
>> cifs_get_tcon() could return any of the following errors:
>> -ENOMEM/-ENODEV/EREMOTEIO. We should follow the DFS referral code path only
>> when we get -EREMOTEIO (STATUS_PATH_NOT_COVERED) from the server and not
>> otherwise.
>>
>> Compile-tested only.
>>
>> Signed-off-by: Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org>
>> ---
>>  fs/cifs/connect.c |    5 ++++-
>>  1 files changed, 4 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
>> index 251a17c..c3a2323 100644
>> --- a/fs/cifs/connect.c
>> +++ b/fs/cifs/connect.c
>> @@ -2780,7 +2780,10 @@ try_mount_again:
>>  	if (IS_ERR(tcon)) {
>>  		rc = PTR_ERR(tcon);
>>  		tcon = NULL;
>> -		goto remote_path_check;
>> +		if (rc == -EREMOTEIO)
>> +			goto remote_path_check;
>> +		else
>> +			goto mount_fail_check;
>>  	}
>>  
>>  	/* do not care if following two calls succeed - informational */
> 
> Don't you mean "EREMOTE" here? I've always interpreted "EREMOTEIO" to

Doh, yes. 

> mean that the server had the equivalent of an I/O error, whereas
> "EREMOTE" means "Object is remote".
> 
> I don't see how this patch materially changes anything. Pseudocode,
> assuming that rc == -EREMOTE:

I agree that this is not an improvement (more of a cleanup), but I think
it improves readability (given that the single function runs for more than 
hundred lines), and skips a couple of unneeded checks.

Here's a fixed version (but this patch can be ignored if we feel so):


cifs_get_tcon() could return any of the following errors:
-ENOMEM/-ENODEV/EREMOTEIO. We should follow the DFS referral code path only
when we get -EREMOTEIO (STATUS_PATH_NOT_COVERED) from the server and not
otherwise.

Compile-tested only.

Signed-off-by: Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org>
--- 
 fs/cifs/connect.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 251a17c..6dbc145 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2780,7 +2780,10 @@ try_mount_again:
 	if (IS_ERR(tcon)) {
 		rc = PTR_ERR(tcon);
 		tcon = NULL;
-		goto remote_path_check;
+		if (rc == -EREMOTE)
+			goto remote_path_check;
+		else
+			goto mount_fail_check;
 	}
 
 	/* do not care if following two calls succeed - informational */