On Wed, Dec 7, 2016 at 2:27 PM, Jan Tulak <jtulak@xxxxxxxxxx> wrote: > Hi guys, > > this set is a follow-up of some old discussions and further attempts to untangle > the spaghetti in options parsing. In short, this patchset allows to define > cross-option conflicts and makes the conflicts detection more robust. > > Until now, we had the ability to define conflicts within one option (e.g. -d > sunit/su), but things like -i attr=1 -m crc=1 conflict had to be watched for on > case by case basis somewhere in the code. Now, when even those situations are > handled by the same code, it is enough to just add a new entry into a table of > options. Thus, a reduced chance for an error and easier adding of new cases. > > One of the biggest changes in this set is that user input is now stored in > directly in the opts table defining allowed range and the like, and variables > in the main() of mkfs.xfs are now just aliases/pointers. This allows as to do > conditional checks based on actual values, not only on occurence of an option. > > (A technical note here is that not every value can be saved in a single place > like this. Some values are already stored in a table or structure and I wanted > to avoid modifying anything outside of xfs_mkfs.c.) > > I tested it with full xfstests suit and the only failed tests I saw are because > some ambiguity in arguments parsing was removed. E.g. sometimes it was possible > to specify size in blocks without stating the blocksize first, even if manpage > explicitly requires -b or -s to be used before. > > I already submitted part of this patchset as RFC before, but as I got no reply, > I tried to finish it before submitting again. So, this set works as it is. I > still have some questions, but they can be answered with "let's keep it as it > is." > > Number one is simple: What values can use block/sector sizes as user input? > There is an inconsistency or ambiguity between manual page and the code. Look > at man page for -d agsize. > > agsize=value > This is an alternative to using the agcount subop‐ > tion. The value is the desired size of the alloca‐ > tion group expressed in bytes (usually using the m > ^^^^^^^^ > or g suffixes). This value must be a multiple of > [ ... ] > > > The option -d agsize explicitly states that it accepts size in bytes, in a > similar tone to the one used for describe allowed values for -s/-b size: > > value in bytes with size=value > ^^^^^^^^ > > However, -d agsize=1234s input was accepted as valid until now. Is the manual > page misleading, or are the options where b/s suffix is forbidden are > block/sector size definitions? I decided to err on the compatibility side and > kept the current behaviour - only blocksize or sectorsize can't be stated in > blocks and sectors, but it can be easily changed. > > I will send an update for xfstests once I know what behaviour is correct. > > > The other question about this patchset is: As we are saving all the values in > the opt_params table, and the values have different types, I thought it > necessary to not use a single data type for everything and created an union > field (could be easily changed to struct, that would not change anything > important). Do you see any non-adressed issue with this approach? Is there > another way how to solve the problem? > > If nothing else, numbers and strings can't be easily saved in a single > variable. Also, as we are using shift operations, any type conversions > (like storing everything in long long type) could cause trouble. This is one of > the reasons why I'm changed the variables in main() to pointers. This allows > for simple and easy access to the correct union field, so unless one is adding > a new option, there should be no need to remember the correct date type. If the > pointer assignment is done correctly, then GCC will watch for type mismatch. > > I really couldn't find out better solution, but see for yourself, this change > is done in "mkfs: Change all value fields in opt structures into unions" > and "mkfs: use old variables as pointers to the new opts struct values". > > > So, I think this is all I wanted to cover in the cover letter. :-) > I will be glad for any comments or bugs you find out. > > Thanks for your time, > > Jan > > > Jan Tulak (22): > mkfs: remove intermediate getstr followed by getnum > mkfs: merge tables for opts parsing into one table > mkfs: extend opt_params with a value field > mkfs: change conflicts array into a table capable of cross-option > addressing > mkfs: add a check for conflicting values > mkfs: add cross-section conflict checks > mkfs: Move opts related #define to one place > mkfs: move conflicts into the table > mkfs: change conflict checks to utilize the new conflict structure > mkfs: change when to mark an option as seen > mkfs: add test_default_value into conflict struct > mkfs: expand conflicts declarations to named declaration > mkfs: remove zeroed items from conflicts declaration > mkfs: rename defaultval to flagval in opts > mkfs: replace SUBOPT_NEEDS_VAL for a flag > mkfs: Change all value fields in opt structures into unions > mkfs: use old variables as pointers to the new opts struct values > mkfs: prevent sector/blocksize to be specified as a number of blocks > mkfs: subopt flags should be saved as bool > mkfs: move uuid empty string test to getstr() > mkfs: remove duplicit checks > mkfs: prevent multiple specifications of a single option > > mkfs/xfs_mkfs.c | 2952 +++++++++++++++++++++++++++++++++++-------------------- > 1 file changed, 1864 insertions(+), 1088 deletions(-) > > -- > 2.8.1 > Hi guys, I'm just pinging this up. If there are no issues with it, I will rebase it on top of new releases and send it again without the RFC. Cheers, Jan -- Jan Tulak jtulak@xxxxxxxxxx / jan@xxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
