Andreas,

Thanks for the info.  A related question:  I am using the O_LOV_DELAY_CREATE open flag mechanism to open a file and then set the composite layout with llapi_layout_file_open().  I was kind of surprised this worked.  This ends up opening the file twice and I simply close the fd returned from llapi_layout_file_open().  It would seem there should be an llapi function such as llapi_layout_set_by_fd() to match the llapi_layout_get_by_fd().  I need to use this mechanism to set striping for files where the pathname is not necessarily known before the open, such as the mkstemps() family of opens.  It also makes it easier to handle setting striping for files opened with openat().  It seems it would be more straight forward for llapi to work with an fd than a pathname if a valid fd already exists. Am I missing an easier way to do this?

Thanks,

John

On 7/27/22 16:25, Andreas Dilger wrote:
The HLD document was written before the feature was implemented, and is outdated.  The lustreapi.h and llapi_layout_file_comp_del.3 man page are correct.  Feel free to update the wiki to use the correct argument list.

I believe that it is possible to delete multiple components that match the <flags> argument (e.g. LCME_FL_NEG|LCME_FL_INIT), but I haven't tested that.

On Jul 26, 2022, at 14:35, John Bauer <[email protected]> wrote:

Hi all,

I would like to use the llapi_layout_file_comp_del() function.  I have found 2 prototypes in different places.  One has the 3rd argument, uint32_t flags, and the other doesn't.  I suspect the High Level Design document is incorrect.  The one line of documentation in lustreapi.h indicates I could delete multiple components with one call.  How does one do that? What are the applicable flags?

From version 2.12.8 lustreapi.h

/**
* Delete component(s) by the specified component id or flags.
*/
int  llapi_layout_file_comp_del(const  char  *path, uint32_t  id, uint32_t  flags);


From https://wiki.lustre.org/PFL2_High_Level_Design

A new interface llapi_layout_file_comp_del(3) to delete component(s) by the specified component id (accepting LCME_ID_* wildcards also) from an existing file:

int llapi_layout_file_comp_del(const char *path, uint32_t id);

John

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Cheers, Andreas
--
Andreas Dilger
Lustre Principal Architect
Whamcloud






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