vfs: hoist the btrfs deduplication ioctl to the vfs
Hoist the btrfs EXTENT_SAME ioctl up to the VFS and make the name
more systematic (FIDEDUPERANGE).
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/read_write.c b/fs/read_write.c
index 60ee269..2116e74 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1523,3 +1523,103 @@
return ret;
}
EXPORT_SYMBOL(vfs_clone_file_range);
+
+int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
+{
+ struct file_dedupe_range_info *info;
+ struct inode *src = file_inode(file);
+ u64 off;
+ 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;
+ ssize_t deduped;
+
+ if (!(file->f_mode & FMODE_READ))
+ return -EINVAL;
+
+ if (same->reserved1 || same->reserved2)
+ return -EINVAL;
+
+ off = same->src_offset;
+ len = same->src_length;
+
+ ret = -EISDIR;
+ if (S_ISDIR(src->i_mode))
+ goto out;
+
+ ret = -EINVAL;
+ if (!S_ISREG(src->i_mode))
+ goto out;
+
+ ret = clone_verify_area(file, off, len, false);
+ if (ret < 0)
+ goto out;
+ ret = 0;
+
+ /* pre-format output fields to sane values */
+ for (i = 0; i < count; i++) {
+ same->info[i].bytes_deduped = 0ULL;
+ same->info[i].status = 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);
+
+ 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,
+ len, dst_file,
+ info->dest_offset);
+ if (deduped == -EBADE)
+ info->status = FILE_DEDUPE_RANGE_DIFFERS;
+ else if (deduped < 0)
+ info->status = deduped;
+ else
+ info->bytes_deduped += deduped;
+ }
+
+next_file:
+ mnt_drop_write_file(dst_file);
+next_loop:
+ fdput(dst_fd);
+ }
+
+out:
+ return ret;
+}
+EXPORT_SYMBOL(vfs_dedupe_file_range);