LLAPI_LAYOUT_COMP_ADD(3)

💖 LLAPI_LAYOUT_COMP_ADD(3) 💖

okay bestie, welcome to the Lustre Library Functions corner of the manual, this one's about llapi_layout_comp_add and llapi_layout_comp_del — yes they share a page, they're a package deal, like us 🫶

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✨ NAME ✨

llapi_layout_comp_add, llapi_layout_comp_del — add or delete a layout component into/from the layout.

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🌸 SYNOPSIS 🌸

#include <lustre/lustreapi.h>

int llapi_layout_comp_add(struct llapi_layout *layout,
                          struct llapi_layout *comp);

int llapi_layout_comp_del(struct llapi_layout *layout,
                          struct llapi_layout *comp);

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🦋 DESCRIPTION 🦋

so a composite layout? it's literally made of several layout components. that's the whole vibe. multiple pieces, one layout. iconic.

llapi_layout_comp_add(3) adds the layout component comp into the existing in-memory layout under construction, and comp is freed. yes, freed — she's absorbed, she's part of the family now, don't go touching her afterwards 😭

The layout will be turned into composite if it was plain before adding. a glow-up, fr fr.

All layout attributes of comp will be inherited from the layout, unless otherwise specified for this component by llapi_layout_*_set(3) functions. so the defaults are inherited, but you can override per-component with the setter functions, iykyk.

llapi_layout_comp_del(3) deletes the layout component comp from the in-memory layout, but does not delete the component from an existing file layout on the MDT. ⚠️ read that again bestie — in-memory only. the MDT is unaffected. do not come crying to me when your file still has the component on disk.

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🎀 RETURN VALUES 🎀

Both llapi_layout_comp_add() and llapi_layout_comp_del() return 0 on success, or -1 if an error occurred (in which case, errno is set appropriately). classic, love that for them 💅

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💀 ERRORS 💀

• EINVAL — An invalid argument was specified. something you passed was not it, bestie 🙈

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🌈 AVAILABILITY 🌈

llapi_layout_comp_add() and llapi_layout_comp_del() are part of the lustre(7) user application interface library since release 2.10.0. so they've been serving looks for a while now 👑

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👑 SEE ALSO 👑

• llapi_layout_alloc(3)
• llapi_layout_file_comp_add(3)
• llapi_layout_file_comp_del(3)
• llapi_layout_file_open(3)
• llapi_layout_free(3)
• llapi_layout(7)
• lustreapi(7)

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lowkey feel free to go read those too, they're all besties in the same friend group 🫶

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and that's the whole page, no cap 💖 this fine piece of documentation came to you from the Lustre User API, dated 2024-08-27, and it lives at LLAPI_LAYOUT_COMP_ADD(3) — periodt ✨