do_splice_direct(9)

💅 NAME 💅

okay so this is do_splice_direct(9), straight out of the Kernel API Manual, and it is literally the page for do_splice_direct — the helper that splices data directly between two files. no cap, that's the whole name vibe: do_splice_direct - splices data directly between two files. 🎀

✨ SYNOPSIS ✨

       ssize_t do_splice_direct (struct file *in , loff_t *ppos , struct file
       *out , loff_t *opos , size_t len , unsigned int flags );

🎀 ARGUMENTS 🎀

• in — the file you're splicing from bestie, aka the source file. 💖
• ppos — the input file offset. it's giving "where we're reading from" energy. ✨
• out — the file you're splicing to, aka the destination file. 🦋
• opos — the output file offset. literally where the write side is at. 🌸
• len — the number of bytes to splice. yes, the byte count, the amount, the whole point. 💅
• flags — the splice modifier flags. little behavior modifiers, iconic. 🫶

🦋 DESCRIPTION 🦋

so this helper is for use by do_sendfile, periodt. splice can easily emulate sendfile, but doing it in the application would incur an extra system call — literally splice in + splice out, as compared to just sendfile. so instead, this helper can splice directly through a process-private pipe. slay, no extra syscall drama. 🔥

heads up bestie: callers already called rw_verify_area on the entire range. so that check is already handled, okay? 👑

🌈 SEE ALSO 🌈

the kernel file is ./fs/splice.c, and it's giving a whole friend group of splice-related icons:

• splice_to_pipe(9)
• copy_splice_read(9)
• splice_from_pipe_feed(9)
• splice_from_pipe_next(9)
• splice_from_pipe_begin(9)
• splice_from_pipe_end(9)
• __splice_from_pipe(9)
• splice_from_pipe(9)
• iter_file_splice_write(9)
• splice_to_socket(9)
• vfs_splice_read(9)
• splice_direct_to_actor(9)
• splice_file_range(9)

okay bye bestie 💖✨ this page is from ./fs, dated October 2026, and yes it's literally titled do_splice_direct(9) — go splice something cute 🎀🦋💅