Btrfs: extended inode refs support for send mechanism

This adds support for the new extended inode refs to btrfs send.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>

3 files changed, 94 insertions, 58 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 2bcbea3f6308..b8b69266393a 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1177,11 +1177,10 @@ int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
         return ret;
 }
 
-static char *ref_to_path(struct btrfs_root *fs_root,
-                         struct btrfs_path *path,
-                         u32 name_len, unsigned long name_off,
-                         struct extent_buffer *eb_in, u64 parent,
-                         char *dest, u32 size)
+char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
+                        u32 name_len, unsigned long name_off,
+                        struct extent_buffer *eb_in, u64 parent,
+                        char *dest, u32 size)
 {
         int slot;
         u64 next_inum;
@@ -1266,10 +1265,10 @@ char *btrfs_iref_to_path(struct btrfs_root *fs_root,
                          struct extent_buffer *eb_in, u64 parent,
                          char *dest, u32 size)
 {
-        return ref_to_path(fs_root, path,
-                           btrfs_inode_ref_name_len(eb_in, iref),
-                           (unsigned long)(iref + 1),
-                           eb_in, parent, dest, size);
+        return btrfs_ref_to_path(fs_root, path,
+                                 btrfs_inode_ref_name_len(eb_in, iref),
+                                 (unsigned long)(iref + 1),
+                                 eb_in, parent, dest, size);
 }
 
 /*
@@ -1715,9 +1714,8 @@ static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off,
                                         ipath->fspath->bytes_left - s_ptr : 0;
 
         fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr;
-        fspath = ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len,
-                             name_off, eb, inum, fspath_min,
-                             bytes_left);
+        fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len,
+                                   name_off, eb, inum, fspath_min, bytes_left);
         if (IS_ERR(fspath))
                 return PTR_ERR(fspath);
 
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index e75533043a5f..d61feca79455 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -62,6 +62,10 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
 char *btrfs_iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
                          struct btrfs_inode_ref *iref, struct extent_buffer *eb,
                          u64 parent, char *dest, u32 size);
+char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
+                        u32 name_len, unsigned long name_off,
+                        struct extent_buffer *eb_in, u64 parent,
+                        char *dest, u32 size);
 
 struct btrfs_data_container *init_data_container(u32 total_bytes);
 struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index c7beb543a4a8..4f20c49edd58 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -745,31 +745,36 @@ typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
                                    void *ctx);
 
 /*
- * Helper function to iterate the entries in ONE btrfs_inode_ref.
+ * Helper function to iterate the entries in ONE btrfs_inode_ref or
+ * btrfs_inode_extref.
  * The iterate callback may return a non zero value to stop iteration. This can
  * be a negative value for error codes or 1 to simply stop it.
  *
- * path must point to the INODE_REF when called.
+ * path must point to the INODE_REF or INODE_EXTREF when called.
  */
 static int iterate_inode_ref(struct send_ctx *sctx,
                              struct btrfs_root *root, struct btrfs_path *path,
                              struct btrfs_key *found_key, int resolve,
                              iterate_inode_ref_t iterate, void *ctx)
 {
-        struct extent_buffer *eb;
+        struct extent_buffer *eb = path->nodes[0];
         struct btrfs_item *item;
         struct btrfs_inode_ref *iref;
+        struct btrfs_inode_extref *extref;
         struct btrfs_path *tmp_path;
         struct fs_path *p;
-        u32 cur;
-        u32 len;
+        u32 cur = 0;
         u32 total;
-        int slot;
+        int slot = path->slots[0];
         u32 name_len;
         char *start;
         int ret = 0;
-        int num;
+        int num = 0;
         int index;
+        u64 dir;
+        unsigned long name_off;
+        unsigned long elem_size;
+        unsigned long ptr;
 
         p = fs_path_alloc_reversed(sctx);
         if (!p)
@@ -781,24 +786,40 @@ static int iterate_inode_ref(struct send_ctx *sctx,
                 return -ENOMEM;
         }
 
-        eb = path->nodes[0];
-        slot = path->slots[0];
-        item = btrfs_item_nr(eb, slot);
-        iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
-        cur = 0;
-        len = 0;
-        total = btrfs_item_size(eb, item);
 
-        num = 0;
+        if (found_key->type == BTRFS_INODE_REF_KEY) {
+                ptr = (unsigned long)btrfs_item_ptr(eb, slot,
+                                                    struct btrfs_inode_ref);
+                item = btrfs_item_nr(eb, slot);
+                total = btrfs_item_size(eb, item);
+                elem_size = sizeof(*iref);
+        } else {
+                ptr = btrfs_item_ptr_offset(eb, slot);
+                total = btrfs_item_size_nr(eb, slot);
+                elem_size = sizeof(*extref);
+        }
+
         while (cur < total) {
                 fs_path_reset(p);
 
-                name_len = btrfs_inode_ref_name_len(eb, iref);
-                index = btrfs_inode_ref_index(eb, iref);
+                if (found_key->type == BTRFS_INODE_REF_KEY) {
+                        iref = (struct btrfs_inode_ref *)(ptr + cur);
+                        name_len = btrfs_inode_ref_name_len(eb, iref);
+                        name_off = (unsigned long)(iref + 1);
+                        index = btrfs_inode_ref_index(eb, iref);
+                        dir = found_key->offset;
+                } else {
+                        extref = (struct btrfs_inode_extref *)(ptr + cur);
+                        name_len = btrfs_inode_extref_name_len(eb, extref);
+                        name_off = (unsigned long)&extref->name;
+                        index = btrfs_inode_extref_index(eb, extref);
+                        dir = btrfs_inode_extref_parent(eb, extref);
+                }
+
                 if (resolve) {
-                        start = btrfs_iref_to_path(root, tmp_path, iref, eb,
-                                                found_key->offset, p->buf,
-                                                p->buf_len);
+                        start = btrfs_ref_to_path(root, tmp_path, name_len,
+                                                  name_off, eb, dir,
+                                                  p->buf, p->buf_len);
                         if (IS_ERR(start)) {
                                 ret = PTR_ERR(start);
                                 goto out;
@@ -809,9 +830,10 @@ static int iterate_inode_ref(struct send_ctx *sctx,
                                                 p->buf_len + p->buf - start);
                                 if (ret < 0)
                                         goto out;
-                                start = btrfs_iref_to_path(root, tmp_path, iref,
-                                                eb, found_key->offset, p->buf,
-                                                p->buf_len);
+                                start = btrfs_ref_to_path(root, tmp_path,
+                                                          name_len, name_off,
+                                                          eb, dir,
+                                                          p->buf, p->buf_len);
                                 if (IS_ERR(start)) {
                                         ret = PTR_ERR(start);
                                         goto out;
@@ -820,21 +842,16 @@ static int iterate_inode_ref(struct send_ctx *sctx,
                         }
                         p->start = start;
                 } else {
-                        ret = fs_path_add_from_extent_buffer(p, eb,
-                                        (unsigned long)(iref + 1), name_len);
+                        ret = fs_path_add_from_extent_buffer(p, eb, name_off,
+                                                             name_len);
                         if (ret < 0)
                                 goto out;
                 }
 
-
-                len = sizeof(*iref) + name_len;
-                iref = (struct btrfs_inode_ref *)((char *)iref + len);
-                cur += len;
-
-                ret = iterate(num, found_key->offset, index, p, ctx);
+                cur += elem_size + name_len;
+                ret = iterate(num, dir, index, p, ctx);
                 if (ret)
                         goto out;
-
                 num++;
         }
 
@@ -998,7 +1015,8 @@ static int get_inode_path(struct send_ctx *sctx, struct btrfs_root *root,
         }
         btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
         if (found_key.objectid != ino ||
-                found_key.type != BTRFS_INODE_REF_KEY) {
+            (found_key.type != BTRFS_INODE_REF_KEY &&
+             found_key.type != BTRFS_INODE_EXTREF_KEY)) {
                 ret = -ENOENT;
                 goto out;
         }
@@ -1551,8 +1569,8 @@ static int get_first_ref(struct send_ctx *sctx,
         struct btrfs_key key;
         struct btrfs_key found_key;
         struct btrfs_path *path;
-        struct btrfs_inode_ref *iref;
         int len;
+        u64 parent_dir;
 
         path = alloc_path_for_send();
         if (!path)
@@ -1568,27 +1586,41 @@ static int get_first_ref(struct send_ctx *sctx,
         if (!ret)
                 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
                                 path->slots[0]);
-        if (ret || found_key.objectid != key.objectid ||
-            found_key.type != key.type) {
+        if (ret || found_key.objectid != ino ||
+            (found_key.type != BTRFS_INODE_REF_KEY &&
+             found_key.type != BTRFS_INODE_EXTREF_KEY)) {
                 ret = -ENOENT;
                 goto out;
         }
 
-        iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
-                        struct btrfs_inode_ref);
-        len = btrfs_inode_ref_name_len(path->nodes[0], iref);
-        ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
-                        (unsigned long)(iref + 1), len);
+        if (key.type == BTRFS_INODE_REF_KEY) {
+                struct btrfs_inode_ref *iref;
+                iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                      struct btrfs_inode_ref);
+                len = btrfs_inode_ref_name_len(path->nodes[0], iref);
+                ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
+                                                     (unsigned long)(iref + 1),
+                                                     len);
+                parent_dir = found_key.offset;
+        } else {
+                struct btrfs_inode_extref *extref;
+                extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                        struct btrfs_inode_extref);
+                len = btrfs_inode_extref_name_len(path->nodes[0], extref);
+                ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
+                                        (unsigned long)&extref->name, len);
+                parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
+        }
         if (ret < 0)
                 goto out;
         btrfs_release_path(path);
 
-        ret = get_inode_info(root, found_key.offset, NULL, dir_gen, NULL, NULL,
+        ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
                         NULL, NULL);
         if (ret < 0)
                 goto out;
 
-        *dir = found_key.offset;
+        *dir = parent_dir;
 
 out:
         btrfs_free_path(path);
@@ -3226,7 +3258,8 @@ static int process_all_refs(struct send_ctx *sctx,
                 btrfs_item_key_to_cpu(eb, &found_key, slot);
 
                 if (found_key.objectid != key.objectid ||
-                    found_key.type != key.type)
+                    (found_key.type != BTRFS_INODE_REF_KEY &&
+                     found_key.type != BTRFS_INODE_EXTREF_KEY))
                         break;
 
                 ret = iterate_inode_ref(sctx, root, path, &found_key, 0, cb,
@@ -3987,7 +4020,7 @@ static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end)
         if (sctx->cur_ino == 0)
                 goto out;
         if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
-            sctx->cmp_key->type <= BTRFS_INODE_REF_KEY)
+            sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
                 goto out;
         if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
                 goto out;
@@ -4335,7 +4368,8 @@ static int changed_cb(struct btrfs_root *left_root,
 
         if (key->type == BTRFS_INODE_ITEM_KEY)
                 ret = changed_inode(sctx, result);
-        else if (key->type == BTRFS_INODE_REF_KEY)
+        else if (key->type == BTRFS_INODE_REF_KEY ||
+                 key->type == BTRFS_INODE_EXTREF_KEY)
                 ret = changed_ref(sctx, result);
         else if (key->type == BTRFS_XATTR_ITEM_KEY)
                 ret = changed_xattr(sctx, result);