3 files changed, 16 insertions, 97 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index dd4733fa882c..b7e4e344e8e0 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -4024,6 +4024,8 @@ void btrfs_get_block_group_info(struct list_head *groups_list,
                                 struct btrfs_ioctl_space_info *space);
 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
                                struct btrfs_ioctl_balance_args *bargs);
+ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
+                           struct file *dst_file, u64 dst_loff);
 
 /* file.c */
 int btrfs_auto_defrag_init(void);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 232e300a6c93..d012e0a96ec3 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2926,6 +2926,7 @@ const struct file_operations btrfs_file_operations = {
 #endif
         .copy_file_range = btrfs_copy_file_range,
         .clone_file_range = btrfs_clone_file_range,
+        .dedupe_file_range = btrfs_dedupe_file_range,
 };
 
 void btrfs_auto_defrag_exit(void)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 85b1caeeec85..e21997385d14 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2962,7 +2962,7 @@ static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
                 flush_dcache_page(dst_page);
 
                 if (memcmp(addr, dst_addr, cmp_len))
-                        ret = BTRFS_SAME_DATA_DIFFERS;
+                        ret = -EBADE;
 
                 kunmap_atomic(addr);
                 kunmap_atomic(dst_addr);
@@ -3098,53 +3098,16 @@ out_unlock:
 
 #define BTRFS_MAX_DEDUPE_LEN    (16 * 1024 * 1024)
 
-static long btrfs_ioctl_file_extent_same(struct file *file,
-                        struct btrfs_ioctl_same_args __user *argp)
+ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
+                                struct file *dst_file, u64 dst_loff)
 {
-        struct btrfs_ioctl_same_args *same = NULL;
-        struct btrfs_ioctl_same_extent_info *info;
-        struct inode *src = file_inode(file);
-        u64 off;
-        u64 len;
-        int i;
-        int ret;
-        unsigned long size;
+        struct inode *src = file_inode(src_file);
+        struct inode *dst = file_inode(dst_file);
         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
-        bool is_admin = capable(CAP_SYS_ADMIN);
-        u16 count;
-
-        if (!(file->f_mode & FMODE_READ))
-                return -EINVAL;
+        ssize_t res;
 
-        ret = mnt_want_write_file(file);
-        if (ret)
-                return ret;
-
-        if (get_user(count, &argp->dest_count)) {
-                ret = -EFAULT;
-                goto out;
-        }
-
-        size = offsetof(struct btrfs_ioctl_same_args __user, info[count]);
-
-        same = memdup_user(argp, size);
-
-        if (IS_ERR(same)) {
-                ret = PTR_ERR(same);
-                same = NULL;
-                goto out;
-        }
-
-        off = same->logical_offset;
-        len = same->length;
-
-        /*
-         * Limit the total length we will dedupe for each operation.
-         * This is intended to bound the total time spent in this
-         * ioctl to something sane.
-         */
-        if (len > BTRFS_MAX_DEDUPE_LEN)
-                len = BTRFS_MAX_DEDUPE_LEN;
+        if (olen > BTRFS_MAX_DEDUPE_LEN)
+                olen = BTRFS_MAX_DEDUPE_LEN;
 
         if (WARN_ON_ONCE(bs < PAGE_CACHE_SIZE)) {
                 /*
@@ -3152,58 +3115,13 @@ static long btrfs_ioctl_file_extent_same(struct file *file,
                  * result, btrfs_cmp_data() won't correctly handle
                  * this situation without an update.
                  */
-                ret = -EINVAL;
-                goto out;
-        }
-
-        ret = -EISDIR;
-        if (S_ISDIR(src->i_mode))
-                goto out;
-
-        ret = -EACCES;
-        if (!S_ISREG(src->i_mode))
-                goto out;
-
-        /* pre-format output fields to sane values */
-        for (i = 0; i < count; i++) {
-                same->info[i].bytes_deduped = 0ULL;
-                same->info[i].status = 0;
-        }
-
-        for (i = 0, info = same->info; i < count; i++, info++) {
-                struct inode *dst;
-                struct fd dst_file = fdget(info->fd);
-                if (!dst_file.file) {
-                        info->status = -EBADF;
-                        continue;
-                }
-                dst = file_inode(dst_file.file);
-
-                if (!(is_admin || (dst_file.file->f_mode & FMODE_WRITE))) {
-                        info->status = -EINVAL;
-                } else if (file->f_path.mnt != dst_file.file->f_path.mnt) {
-                        info->status = -EXDEV;
-                } else if (S_ISDIR(dst->i_mode)) {
-                        info->status = -EISDIR;
-                } else if (!S_ISREG(dst->i_mode)) {
-                        info->status = -EACCES;
-                } else {
-                        info->status = btrfs_extent_same(src, off, len, dst,
-                                                        info->logical_offset);
-                        if (info->status == 0)
-                                info->bytes_deduped += len;
-                }
-                fdput(dst_file);
+                return -EINVAL;
         }
 
-        ret = copy_to_user(argp, same, size);
-        if (ret)
-                ret = -EFAULT;
-
-out:
-        mnt_drop_write_file(file);
-        kfree(same);
-        return ret;
+        res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
+        if (res)
+                return res;
+        return olen;
 }
 
 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
@@ -5536,8 +5454,6 @@ long btrfs_ioctl(struct file *file, unsigned int
                 return btrfs_ioctl_get_fslabel(file, argp);
         case BTRFS_IOC_SET_FSLABEL:
                 return btrfs_ioctl_set_fslabel(file, argp);
-        case BTRFS_IOC_FILE_EXTENT_SAME:
-                return btrfs_ioctl_file_extent_same(file, argp);
         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
                 return btrfs_ioctl_get_supported_features(file, argp);
         case BTRFS_IOC_GET_FEATURES: