file_start_write(9)

🦋 file_start_write(9) 🦋

okay so this little cutie is from the Kernel API Manual, and she's here to explain getting write access to a superblock for regular file io. slay. 💅

🌸 NAME 🌸

file_start_write — get write access to a superblock for regular file io ✨

✨ SYNOPSIS ✨

void file_start_write (struct file *file );

🎀 ARGUMENTS 🎀

• file — the file we want to write to, bestie. that's the whole vibe. 🫶

💖 DESCRIPTION 💖

okay so real talk: this is a variant of sb_start_write that is a complete noop on non-regular files. literally does nothing there, no cap. 🧚

and because we're not chaotic, it should be matched with a call to file_end_write. like, start the write access, then end it. balance. periodt. 🎀

🌈 SEE ALSO 🌈

• Kernel file ./include/linux/fs.h
• enum positive_aop_returns(9)
• struct address_space(9)
• struct file_ra_state(9)
• struct file(9)
• i_uid_into_vfsuid(9)
• i_uid_needs_update(9)
• i_uid_update(9)
• i_gid_into_vfsgid(9)
• i_gid_needs_update(9)
• i_gid_update(9)
• inode_fsuid_set(9)
• inode_fsgid_set(9)
• fsuidgid_has_mapping(9)
• inode_set_ctime(9)
• file_write_started(9)
• file_write_not_started(9)
• struct renamedata(9)
• is_mgtime(9)
• iput_if_not_last(9)
• is_idmapped_mnt(9)
• file_end_write(9)
• kiocb_start_write(9)
• kiocb_end_write(9)
• name_is_dot_dotdot(9)
• name_contains_dotdot(9)
• inode_dio_begin(9)
• inode_dio_end(9)
• generic_ci_validate_strict_name(9)

source/version: ./include/linux 🫶 date: October 2026 🫶 manual: file_start_write(9) — that's the whole cutie, bye bestie! 💖✨