Skip to content

Align struct file_operations with upstream v6.14 #311

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
+12 −6
Open

Align struct file_operations with upstream v6.14 #311

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 12 additions & 6 deletions lkmpg.tex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -908,46 +908,52 @@ \subsection{The file\_operations Structure}

For example, every character driver needs to define a function that reads from the device.
The \cpp|file_operations| structure holds the address of the module's function that performs that operation.
Here is what the definition looks like for kernel 5.4:
Here is what the definition looks like for kernel 6.14:
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Don't do that. Linux v5.4 is a long-term support kernel. LKMPG maintains compatibility with LTS kernels, which means all content should be compatible with Linux v5.4 and newer versions, rather than focusing exclusively on recent Linux releases. Instead of modifying the struct definitions, please document any changes to member fields in the descriptions.

Copy link
Contributor Author

@Jordymalone Jordymalone Apr 24, 2025 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks for your clarification! That make sense.
I just want to confirm that my understanding aligns with your intent:

I’ll revert the struct file_operations example to the original Linux 5.4 definition (undoing my earlier changes) so it stays compatible with all LTS kernels.

To cover newer kernels without breaking the build, I’ll add a short note right after the code that lists the fields added, removed, or modified since 5.4.

As of Linux kernel 6.12, several member fields have been added or removed, or had their prototypes changed:

  • Added: fop_flags, splice_eof, uring_cmd, uring_cmd_iopoll, mmap_capabilities
  • Removed: iterate, sendpage, mmap_supported_flags (!CONFIG_MMU)
  • Modified:
    • iopoll now takes struct io_comp_batch * and unsigned int flags
    • setlease now uses struct file_lease ** and int instead of long

Let me know if this approach fits the documentation style you prefer, or if you'd suggest any adjustments.


\begin{code}
struct file_operations {
struct module *owner;
fop_flags_t fop_flags;
loff_t (*llseek) (struct file *, loff_t, int);
ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
int (*iopoll)(struct kiocb *kiocb, bool spin);
int (*iterate) (struct file *, struct dir_context *);
int (*iopoll)(struct kiocb *kiocb, struct io_comp_batch *,
unsigned int flags);
int (*iterate_shared) (struct file *, struct dir_context *);
__poll_t (*poll) (struct file *, struct poll_table_struct *);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
unsigned long mmap_supported_flags;
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
int (*fsync) (struct file *, loff_t, loff_t, int datasync);
int (*fasync) (int, struct file *, int);
int (*lock) (struct file *, int, struct file_lock *);
ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
int (*check_flags)(int);
int (*flock) (struct file *, int, struct file_lock *);
ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
int (*setlease)(struct file *, long, struct file_lock **, void **);
void (*splice_eof)(struct file *file);
int (*setlease)(struct file *, int, struct file_lease **, void **);
long (*fallocate)(struct file *file, int mode, loff_t offset,
loff_t len);
void (*show_fdinfo)(struct seq_file *m, struct file *f);
#ifndef CONFIG_MMU
unsigned (*mmap_capabilities)(struct file *);
#endif
ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
loff_t, size_t, unsigned int);
loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
loff_t len, unsigned int remap_flags);
int (*fadvise)(struct file *, loff_t, loff_t, int);
int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);
int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
unsigned int poll_flags);
} __randomize_layout;
\end{code}

Expand Down