On Thu, Dec 31, 2020 at 06:23:58PM +0300, Konstantin Komarov wrote:
> This adds NTFS journal
> 
> Signed-off-by: Konstantin Komarov <almaz.alexandrov...@paragon-software.com>
> ---
>  fs/ntfs3/fslog.c | 5220 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 5220 insertions(+)
>  create mode 100644 fs/ntfs3/fslog.c
> 
> diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c

> +static int read_log_page(struct ntfs_log *log, u32 vbo,
> +                      struct RECORD_PAGE_HDR **buffer, bool allow_errors,
> +                      bool ignore_usa_error, bool *usa_error)

Allow_errors does nothing. I also think that no need for
ignore_usa_error. We can just check usa_error if we need
it. We just never raise return error for usa_error. And
then caller can decide if want's to use it. 

> +{
> +     int err = 0;
> +     u32 page_idx = vbo >> log->page_bits;
> +     u32 page_off = vbo & log->page_mask;
> +     u32 bytes = log->page_size - page_off;
> +     void *to_free = NULL;
> +     u32 page_vbo = page_idx << log->page_bits;
> +     struct RECORD_PAGE_HDR *page_buf;
> +     struct ntfs_inode *ni = log->ni;
> +     bool bBAAD;
> +
> +     if (vbo >= log->l_size)
> +             return -EINVAL;
> +
> +     if (!*buffer) {
> +             to_free = ntfs_alloc(bytes, 0);
> +             if (!to_free)
> +                     return -ENOMEM;
> +             *buffer = to_free;
> +     }
> +
> +     page_buf = page_off ? log->one_page_buf : *buffer;
> +
> +     err = ntfs_read_run_nb(ni->mi.sbi, &ni->file.run, page_vbo, page_buf,
> +                            log->page_size, NULL);
> +     if (err)
> +             goto out;
> +
> +     if (page_buf->rhdr.sign != NTFS_FFFF_SIGNATURE)
> +             ntfs_fix_post_read(&page_buf->rhdr, PAGE_SIZE, false);
> +
> +     if (page_buf != *buffer)
> +             memcpy(*buffer, Add2Ptr(page_buf, page_off), bytes);
> +
> +     bBAAD = page_buf->rhdr.sign == NTFS_BAAD_SIGNATURE;
> +
> +     /* Check that the update sequence array for this page is valid */
> +     if (bBAAD) {
> +             /* If we don't allow errors, raise an error status */
> +             if (!ignore_usa_error) {
> +                     err = -EINVAL;
> +                     goto out;
> +             }
> +     }
> +
> +     if (usa_error)
> +             *usa_error = bBAAD;
> +

So here we can just
        delete if(bBAAD)
and use
        if (usa_error)
                *usa_error = page_buf->rhdr.sign == NTFS_BAAD_SIGNATURE;

> +out:
> +     if (err && to_free) {
> +             ntfs_free(to_free);
> +             *buffer = NULL;
> +     }
> +
> +     return err;
> +}

> +/*
> + * last_log_lsn
> + *
> + * This routine walks through the log pages for a file, searching for the
> + * last log page written to the file
> + */
> +static int last_log_lsn(struct ntfs_log *log)
> +{

> +     struct RECORD_PAGE_HDR *first_tail = NULL;
> +     struct RECORD_PAGE_HDR *second_tail = NULL;

> +next_tail:
> +     /* Read second tail page (at pos 3/0x12000) */
> +     if (read_log_page(log, second_off, &second_tail, true, true,
> +                       &usa_error) ||
> +         usa_error || second_tail->rhdr.sign != NTFS_RCRD_SIGNATURE) {
> +             ntfs_free(second_tail);
> +             second_tail = NULL;
> +             second_file_off = 0;
> +             lsn2 = 0;
> +     } else {
> +             second_file_off = hdr_file_off(log, second_tail);
> +             lsn2 = le64_to_cpu(second_tail->record_hdr.last_end_lsn);
> +     }

What will happend if we get -ENOMEM from read_log_page(). Log page
might still be valid we will just ignore it. This doesn't sound 
right. 

This same thing happens many place with read_log_page().

> +
> +     /* Read first tail page (at pos 2/0x2000 ) */
> +     if (read_log_page(log, final_off, &first_tail, true, true,
> +                       &usa_error) ||
> +         usa_error || first_tail->rhdr.sign != NTFS_RCRD_SIGNATURE) {
> +             ntfs_free(first_tail);
> +             first_tail = NULL;
> +             first_file_off = 0;
> +             lsn1 = 0;
> +     } else {
> +             first_file_off = hdr_file_off(log, first_tail);
> +             lsn1 = le64_to_cpu(first_tail->record_hdr.last_end_lsn);
> +     }

> +     if (first_tail && second_tail) {
> +             if (best_lsn1 > best_lsn2) {
> +                     best_lsn = best_lsn1;
> +                     best_page = first_tail;
> +                     this_off = first_file_off;
> +             } else {
> +                     best_lsn = best_lsn2;
> +                     best_page = second_tail;
> +                     this_off = second_file_off;
> +             }
> +     } else if (first_tail) {
> +             best_lsn = best_lsn1;
> +             best_page = first_tail;
> +             this_off = first_file_off;
> +     } else if (second_tail) {
> +             best_lsn = best_lsn2;
> +             best_page = second_tail;
> +             this_off = second_file_off;
> +     } else {
> +             goto free_and_tail_read;

Can't we just use straight tail_read here? 

> +     }
> +
> +     best_page_pos = le16_to_cpu(best_page->page_pos);

> +     } else {
> +free_and_tail_read:
> +             ntfs_free(first_tail);
> +             ntfs_free(second_tail);
> +             goto tail_read;
> +     }
> +
> +     ntfs_free(first_tail_prev);
> +     first_tail_prev = first_tail;
> +     final_off_prev = first_file_off;
> +     first_tail = NULL;
> +
> +     ntfs_free(second_tail_prev);
> +     second_tail_prev = second_tail;
> +     second_off_prev = second_file_off;
> +     second_tail = NULL;
> +
> +     final_off += log->page_size;
> +     second_off += log->page_size;
> +
> +     if (tails < 0x10)
> +             goto next_tail;
> +tail_read:
> +     first_tail = first_tail_prev;
> +     final_off = final_off_prev;

> +int log_replay(struct ntfs_inode *ni)
> +{

> +     /* Now we need to walk through looking for the last lsn */
> +     err = last_log_lsn(log);
> +     if (err == -EROFS)
> +             goto out;
> +

No need for this if below is whole err check.

> +     if (err)
> +             goto out;
 

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