On Tue, May 29, 2018 at 5:43 PM, Miklos Szeredi <mszeredi@xxxxxxxxxx> wrote:
> Extract vfs_dedupe_file_range_one() helper to deal with a single dedup
> request.
>
> Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
> ---
> fs/read_write.c | 89 +++++++++++++++++++++++++++++++--------------------------
> 1 file changed, 49 insertions(+), 40 deletions(-)
>
> diff --git a/fs/read_write.c b/fs/read_write.c
> index 1818581cadf6..82a53c44c0aa 100644
> --- a/fs/read_write.c
> +++ b/fs/read_write.c
> @@ -1964,6 +1964,44 @@ int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
> }
> EXPORT_SYMBOL(vfs_dedupe_file_range_compare);
>
> +static s64 vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
> + struct file *dst_file, loff_t dst_pos,
> + u64 len)
> +{
> + s64 ret;
> +
> + ret = mnt_want_write_file(dst_file);
> + if (ret)
> + return ret;
> +
> + ret = clone_verify_area(dst_file, dst_pos, len, true);
> + if (ret < 0)
> + goto out_drop_write;
> +
> + ret = -EINVAL;
> + if (!(capable(CAP_SYS_ADMIN) || (dst_file->f_mode & FMODE_WRITE)))
> + goto out_drop_write;
> +
> + ret = -EXDEV;
> + if (src_file->f_path.mnt != dst_file->f_path.mnt)
> + goto out_drop_write;
> +
> + ret = -EISDIR;
> + if (S_ISDIR(file_inode(dst_file)->i_mode))
> + goto out_drop_write;
> +
> + ret = -EINVAL;
> + if (!dst_file->f_op->dedupe_file_range)
> + goto out_drop_write;
> +
> + ret = dst_file->f_op->dedupe_file_range(src_file, src_pos,
> + dst_file, dst_pos, len);
> +out_drop_write:
> + mnt_drop_write_file(dst_file);
> +
> + return ret;
> +}
> +
> int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
> {
> struct file_dedupe_range_info *info;
> @@ -1972,10 +2010,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
> u64 len;
> int i;
> int ret;
> - bool is_admin = capable(CAP_SYS_ADMIN);
> u16 count = same->dest_count;
> - struct file *dst_file;
> - loff_t dst_off;
> loff_t deduped;
>
> if (!(file->f_mode & FMODE_READ))
> @@ -2010,54 +2045,28 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
> }
>
> for (i = 0, info = same->info; i < count; i++, info++) {
> - struct inode *dst;
> struct fd dst_fd = fdget(info->dest_fd);
> + struct file *dst_file = dst_fd.file;
>
> - dst_file = dst_fd.file;
> if (!dst_file) {
> info->status = -EBADF;
> goto next_loop;
> }
> - dst = file_inode(dst_file);
> -
> - ret = mnt_want_write_file(dst_file);
> - if (ret) {
> - info->status = ret;
> - goto next_loop;
> - }
> -
> - dst_off = info->dest_offset;
> - ret = clone_verify_area(dst_file, dst_off, len, true);
> - if (ret < 0) {
> - info->status = ret;
> - goto next_file;
> - }
> - ret = 0;
>
> if (info->reserved) {
> info->status = -EINVAL;
> - } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
> - info->status = -EINVAL;
> - } else if (file->f_path.mnt != dst_file->f_path.mnt) {
> - info->status = -EXDEV;
> - } else if (S_ISDIR(dst->i_mode)) {
> - info->status = -EISDIR;
> - } else if (dst_file->f_op->dedupe_file_range == NULL) {
> - info->status = -EINVAL;
> - } else {
> - deduped = dst_file->f_op->dedupe_file_range(file, off,
> - dst_file,
> - info->dest_offset, len);
> - if (deduped == -EBADE)
> - info->status = FILE_DEDUPE_RANGE_DIFFERS;
> - else if (deduped < 0)
> - info->status = deduped;
> - else
> - info->bytes_deduped += deduped;
> + goto next_loop;
> }
>
> -next_file:
> - mnt_drop_write_file(dst_file);
> + deduped = vfs_dedupe_file_range_one(file, off, dst_file,
> + info->dest_offset, len);
> + if (deduped == -EBADE)
> + info->status = FILE_DEDUPE_RANGE_DIFFERS;
> + else if (deduped < 0)
> + info->status = deduped;
> + else
> + info->bytes_deduped += deduped;
> +
> next_loop:
> fdput(dst_fd);
>
Please note that this patch conflicts with but is also an alternative to commit
227627114799 fs: avoid fdput() after failed fdget() in vfs_dedupe_file_range()
on Al's fixes => for-next branch.
Thanks,
Amir.
