LLAPI_OPEN_BY_FID(3)

✨ NAME ✨

llapi_open_by_fid, llapi_open_by_fid_at — okay so these two cuties open a file descriptor from a File Identifier 🎀 no path-walking drama, we're going straight to the fid periodt

🦋 SYNOPSIS 🦋

#include <lustre/lustreapi.h>

int llapi_open_by_fid(const char *mntpath, struct lu_fid *fid, int oflag);
int llapi_open_by_fid_at(int dir_fd, struct lu_fid *fid, int oflag);

🌸 DESCRIPTION 🌸

So llapi_open_by_fid() opens a file descriptor in the filesystem mountpoint that path points at, and it does it for the file identified by fid, using the open file flags you hand it in oflag — literally exactly like your normal open(2) call does, same energy.

And llapi_open_by_fid_at()? She's the ✨ _at() variant ✨ — she opens a file descriptor on fid in the filesystem referenced by the open file descriptor dir_fd. Think of it like open_by_handle_at(3), that system call that opens files by their NFS file handle (iykyk). Oh and if dir_fd is AT_CWD, then the open happens against the local working directory. iconic. 💅

👑 RETURN VALUES 👑

She returns a file descriptor number when she's slaying 💖 or a negative errno value if it flopped. 😭

💀 ERRORS 💀

• -EINVAL — bestie you passed an invalid argument 🙈
• -ENOMEM — no memory available during the operation, she's running on empty 🫠

🎀 AVAILABILITY 🎀

llapi_open_by_fid() and llapi_open_by_fid_at() are part of the lustre(7) user application interface library, and they've been in the group chat since release 2.4.0. long-running friendship fr fr 🫶

🔥 SEE ALSO 🔥

llapi_fd2fid(3), llapi_fid_parse(3), llapi_fid2path(3), llapi_path2fid(3), open_by_handle_at(3), lustreapi(7)

okay that's the whole page, no skips, no edits, everything's still there 💜 and just so we're keeping receipts: this one's from the Lustre User API, dated 2024-08-27. mwah, go open some fids bestie 💖✨🌸