On Aug 15, 2013, at 11:40 AM, Scott Mayhew <smayhew@xxxxxxxxxx> wrote:
> On Thu, 15 Aug 2013, Chuck Lever wrote:
>
>> Hi Scott-
>>
>> On Aug 15, 2013, at 9:58 AM, Scott Mayhew <smayhew@xxxxxxxxxx> wrote:
>>
>>> This patch makes 2 small improvements to the parsing of the bg, fg, and
>>> sloppy mount options in nfsmount.conf.
>>>
>>> 1. "bg" and "fg" negate should each other. "Background=True" should
>>> mean "bg" and "Background=False" should mean "fg". The same applies to
>>> "Foreground".
>>
>> This looks OK.
>>
>>> 2. Once we see "Sloppy=False" while parsing the configuration file we
>>> should ignore subsequent occurrences of the sloppy option. This will
>>> preserve the "right-most setting wins" behavior for the sloppy mount
>>> option.
>>
>> Here, I'm confused. The "right-most wins" rule goes:
>>
>> 1. mount options are parsed in order from left (closest to the command-line prompt) to right (closest to the carriage return)
>>
>> 2. the last instance of an option (the right-most instance) is the setting that takes effect
>>
>> As I understand it, this applies to config file settings in the following way: config file settings are specified in order from "whole system" to "server" to "mount point", then the command line options are appended to the end of that.
>
> conf_get_mntopts parses the mountpoint specific options first, then the
> server-specific options, and finally global options, inserting each
> option at the head of a list as it goes. It then walks the list and
> appends each option to the string that it ultimately returns to the
> caller. So the order that options appear in the list is reversed from
> how they appear in the string.
For what it's worth:
Acked-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
>>
>> Then, "Right-most wins" means the last occurrence of "Sloppy=true" should override any previous occurrence of "Sloppy=False", right? Or did I misunderstand again?
>
> Yes, this is what it does.
>>
>> It seems like you can just walk the appropriate sections of the config file, and set the sloppiness in each section that has such a setting. The last section you walked with a sloppiness setting wins. After you are done walking, append (or don't) a "sloppy" option, then pass that on to the mount.nfs command.
>>
>> IIUC if the last config file setting is "Sloppy=True" there is no way for command-line options to disable "sloppy".
>
> That's true with the existing code as well though. I don't see any way
> around that besides adding another nfs mount option to the kernel... but
> what is the likelihood that someone would specify sloppy=true in their
> config file and then want to override it from the command line?
>
> -Scott
>>
>>
>>> Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
>>> ---
>>> utils/mount/configfile.c | 11 +++++++++++
>>> 1 file changed, 11 insertions(+)
>>>
>>> diff --git a/utils/mount/configfile.c b/utils/mount/configfile.c
>>> index 1f1b6e7..68b9f93 100644
>>> --- a/utils/mount/configfile.c
>>> +++ b/utils/mount/configfile.c
>>> @@ -73,6 +73,8 @@ struct mnt_alias {
>>> };
>>> int mnt_alias_sz = (sizeof(mnt_alias_tab)/sizeof(mnt_alias_tab[0]));
>>>
>>> +static int strict;
>>> +
>>> /*
>>> * See if the option is an alias, if so return the
>>> * real mount option along with the argument type.
>>> @@ -310,7 +312,15 @@ conf_parse_mntopts(char *section, char *arg, char *opts)
>>> if (strcasecmp(value, "false") == 0) {
>>> if (argtype != MNT_NOARG)
>>> snprintf(buf, BUFSIZ, "no%s", field);
>>> + else if (strcasecmp(field, "bg") == 0)
>>> + snprintf(buf, BUFSIZ, "fg");
>>> + else if (strcasecmp(field, "fg") == 0)
>>> + snprintf(buf, BUFSIZ, "bg");
>>> + else if (strcasecmp(field, "sloppy") == 0)
>>> + strict = 1;
>>> } else if (strcasecmp(value, "true") == 0) {
>>> + if ((strcasecmp(field, "sloppy") == 0) && strict)
>>> + continue;
>>> snprintf(buf, BUFSIZ, "%s", field);
>>> } else {
>>> nvalue = strdup(value);
>>> @@ -345,6 +355,7 @@ char *conf_get_mntopts(char *spec, char *mount_point,
>>> char *ptr, *server, *config_opts;
>>> int optlen = 0;
>>>
>>> + strict = 0;
>>> SLIST_INIT(&head);
>>> list_size = 0;
>>> /*
>>> --
>>> 1.7.11.7
>>>
>>> --
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>>
>> --
>> Chuck Lever
>> chuck[dot]lever[at]oracle[dot]com
>>
>>
>>
>>
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--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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