btrfs-progs: drop slow subvol uuid search

There's a lot of code under BTRFS_COMPAT_SEND_NO_UUID_TREE to support
kernels < 3.12 that don't have uuid tree and the subvolume uuids are
searched in a slow way, building the uuid tree on the userspace side.

As the uuid tree is always created, the fallback code was not exercised
anyway due to 'uuid_tree_existed' check in subvol_uuid_search2.

Delete the code from the internal copy of send-utils. The support still
stays for libbtrfs and will be removed in the future.

Signed-off-by: David Sterba <dsterba@suse.com>

2 files changed, 0 insertions, 397 deletions

diff --git a/common/send-utils.c b/common/send-utils.c
index 0b1a1dd0..e6692e67 100644
--- a/common/send-utils.c
+++ b/common/send-utils.c
@@ -175,73 +175,6 @@ static int btrfs_read_root_item(int mnt_fd, u64 root_id,
 	return 0;
 }
 
-#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
-static struct rb_node *tree_insert(struct rb_root *root,
-				   struct subvol_info *si,
-				   enum subvol_search_type type)
-{
-	struct rb_node **p = &root->rb_node;
-	struct rb_node *parent = NULL;
-	struct subvol_info *entry;
-	__s64 comp;
-
-	while (*p) {
-		parent = *p;
-		if (type == subvol_search_by_received_uuid) {
-			entry = rb_entry(parent, struct subvol_info,
-					rb_received_node);
-
-			comp = memcmp(entry->received_uuid, si->received_uuid,
-					BTRFS_UUID_SIZE);
-			if (!comp) {
-				if (entry->stransid < si->stransid)
-					comp = -1;
-				else if (entry->stransid > si->stransid)
-					comp = 1;
-				else
-					comp = 0;
-			}
-		} else if (type == subvol_search_by_uuid) {
-			entry = rb_entry(parent, struct subvol_info,
-					rb_local_node);
-			comp = memcmp(entry->uuid, si->uuid, BTRFS_UUID_SIZE);
-		} else if (type == subvol_search_by_root_id) {
-			entry = rb_entry(parent, struct subvol_info,
-					rb_root_id_node);
-			comp = entry->root_id - si->root_id;
-		} else if (type == subvol_search_by_path) {
-			entry = rb_entry(parent, struct subvol_info,
-					rb_path_node);
-			comp = strcmp(entry->path, si->path);
-		} else {
-			BUG();
-		}
-
-		if (comp < 0)
-			p = &(*p)->rb_left;
-		else if (comp > 0)
-			p = &(*p)->rb_right;
-		else
-			return parent;
-	}
-
-	if (type == subvol_search_by_received_uuid) {
-		rb_link_node(&si->rb_received_node, parent, p);
-		rb_insert_color(&si->rb_received_node, root);
-	} else if (type == subvol_search_by_uuid) {
-		rb_link_node(&si->rb_local_node, parent, p);
-		rb_insert_color(&si->rb_local_node, root);
-	} else if (type == subvol_search_by_root_id) {
-		rb_link_node(&si->rb_root_id_node, parent, p);
-		rb_insert_color(&si->rb_root_id_node, root);
-	} else if (type == subvol_search_by_path) {
-		rb_link_node(&si->rb_path_node, parent, p);
-		rb_insert_color(&si->rb_path_node, root);
-	}
-	return NULL;
-}
-#endif
-
 int btrfs_subvolid_resolve(int fd, char *path, size_t path_len, u64 subvol_id)
 {
 	if (path_len < 1)
@@ -340,104 +273,6 @@ static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
 	return 0;
 }
 
-#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
-static int count_bytes(void *buf, int len, char b)
-{
-	int cnt = 0;
-	int i;
-
-	for (i = 0; i < len; i++) {
-		if (((char *)buf)[i] == b)
-			cnt++;
-	}
-	return cnt;
-}
-
-void subvol_uuid_search_add(struct subvol_uuid_search *s,
-			    struct subvol_info *si)
-{
-	int cnt;
-
-	tree_insert(&s->root_id_subvols, si, subvol_search_by_root_id);
-	tree_insert(&s->path_subvols, si, subvol_search_by_path);
-
-	cnt = count_bytes(si->uuid, BTRFS_UUID_SIZE, 0);
-	if (cnt != BTRFS_UUID_SIZE)
-		tree_insert(&s->local_subvols, si, subvol_search_by_uuid);
-	cnt = count_bytes(si->received_uuid, BTRFS_UUID_SIZE, 0);
-	if (cnt != BTRFS_UUID_SIZE)
-		tree_insert(&s->received_subvols, si,
-				subvol_search_by_received_uuid);
-}
-
-static struct subvol_info *tree_search(struct rb_root *root,
-				       u64 root_id, const u8 *uuid,
-				       u64 stransid, const char *path,
-				       enum subvol_search_type type)
-{
-	struct rb_node *n = root->rb_node;
-	struct subvol_info *entry;
-	__s64 comp;
-
-	while (n) {
-		if (type == subvol_search_by_received_uuid) {
-			entry = rb_entry(n, struct subvol_info,
-					rb_received_node);
-			comp = memcmp(entry->received_uuid, uuid,
-					BTRFS_UUID_SIZE);
-			if (!comp) {
-				if (entry->stransid < stransid)
-					comp = -1;
-				else if (entry->stransid > stransid)
-					comp = 1;
-				else
-					comp = 0;
-			}
-		} else if (type == subvol_search_by_uuid) {
-			entry = rb_entry(n, struct subvol_info, rb_local_node);
-			comp = memcmp(entry->uuid, uuid, BTRFS_UUID_SIZE);
-		} else if (type == subvol_search_by_root_id) {
-			entry = rb_entry(n, struct subvol_info,
-					 rb_root_id_node);
-			comp = entry->root_id - root_id;
-		} else if (type == subvol_search_by_path) {
-			entry = rb_entry(n, struct subvol_info, rb_path_node);
-			comp = strcmp(entry->path, path);
-		} else {
-			BUG();
-		}
-		if (comp < 0)
-			n = n->rb_left;
-		else if (comp > 0)
-			n = n->rb_right;
-		else
-			return entry;
-	}
-	return NULL;
-}
-
-/*
- * this function will be only called if kernel doesn't support uuid tree.
- */
-static struct subvol_info *subvol_uuid_search_old(struct subvol_uuid_search *s,
-				       u64 root_id, const u8 *uuid, u64 transid,
-				       const char *path,
-				       enum subvol_search_type type)
-{
-	struct rb_root *root;
-	if (type == subvol_search_by_received_uuid)
-		root = &s->received_subvols;
-	else if (type == subvol_search_by_uuid)
-		root = &s->local_subvols;
-	else if (type == subvol_search_by_root_id)
-		root = &s->root_id_subvols;
-	else if (type == subvol_search_by_path)
-		root = &s->path_subvols;
-	else
-		return NULL;
-	return tree_search(root, root_id, uuid, transid, path, type);
-}
-#else
 void subvol_uuid_search_add(struct subvol_uuid_search *s,
 			    struct subvol_info *si)
 {
@@ -446,7 +281,6 @@ void subvol_uuid_search_add(struct subvol_uuid_search *s,
 		free(si);
 	}
 }
-#endif
 
 struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,
 				       u64 root_id, const u8 *uuid, u64 transid,
@@ -470,11 +304,6 @@ struct subvol_info *subvol_uuid_search2(struct subvol_uuid_search *s,
 	struct btrfs_root_item root_item;
 	struct subvol_info *info = NULL;
 
-#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
-	if (!s->uuid_tree_existed)
-		return subvol_uuid_search_old(s, root_id, uuid, transid,
-					     path, type);
-#endif
 	switch (type) {
 	case subvol_search_by_received_uuid:
 		ret = btrfs_lookup_uuid_received_subvol_item(s->mnt_fd, uuid,
@@ -541,210 +370,6 @@ out:
 	return info;
 }
 
-#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
-static int is_uuid_tree_supported(int fd)
-{
-	int ret;
-	struct btrfs_ioctl_search_args args;
-	struct btrfs_ioctl_search_key *sk = &args.key;
-
-	memset(&args, 0, sizeof(args));
-
-	sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
-
-	sk->min_objectid = BTRFS_UUID_TREE_OBJECTID;
-	sk->max_objectid = BTRFS_UUID_TREE_OBJECTID;
-	sk->max_type = BTRFS_ROOT_ITEM_KEY;
-	sk->min_type = BTRFS_ROOT_ITEM_KEY;
-	sk->max_offset = (u64)-1;
-	sk->max_transid = (u64)-1;
-	sk->nr_items = 1;
-
-	ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
-	if (ret < 0)
-		return ret;
-
-	/* the ioctl returns the number of item it found in nr_items */
-	if (sk->nr_items == 0)
-		return 0;
-
-	return 1;
-}
-
-/*
- * this function is mainly used to read all root items
- * it will be only used when we use older kernel which uuid
- * tree is not supported yet
- */
-int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
-{
-	int ret;
-	struct btrfs_ioctl_search_args args;
-	struct btrfs_ioctl_search_key *sk = &args.key;
-	struct btrfs_ioctl_search_header *sh;
-	struct btrfs_root_item *root_item_ptr;
-	struct btrfs_root_item root_item = {};
-	struct subvol_info *si = NULL;
-	int root_item_valid = 0;
-	unsigned long off = 0;
-	int i;
-
-	s->mnt_fd = mnt_fd;
-
-	s->root_id_subvols = RB_ROOT;
-	s->local_subvols = RB_ROOT;
-	s->received_subvols = RB_ROOT;
-	s->path_subvols = RB_ROOT;
-
-	ret = is_uuid_tree_supported(mnt_fd);
-	if (ret < 0) {
-		fprintf(stderr,
-			"ERROR: check if we support uuid tree fails - %m\n");
-		return ret;
-	} else if (ret) {
-		/* uuid tree is supported */
-		s->uuid_tree_existed = 1;
-		return 0;
-	}
-	memset(&args, 0, sizeof(args));
-
-	sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
-
-	sk->max_objectid = (u64)-1;
-	sk->max_offset = (u64)-1;
-	sk->max_transid = (u64)-1;
-	sk->min_type = BTRFS_ROOT_ITEM_KEY;
-	sk->max_type = BTRFS_ROOT_BACKREF_KEY;
-	sk->nr_items = 4096;
-
-	while (1) {
-		ret = ioctl(mnt_fd, BTRFS_IOC_TREE_SEARCH, &args);
-		if (ret < 0) {
-			fprintf(stderr, "ERROR: can't perform the search - %m\n");
-			return ret;
-		}
-		if (sk->nr_items == 0)
-			break;
-
-		off = 0;
-
-		for (i = 0; i < sk->nr_items; i++) {
-			sh = (struct btrfs_ioctl_search_header *)(args.buf +
-								  off);
-			off += sizeof(*sh);
-
-			if ((btrfs_search_header_objectid(sh) != 5 &&
-			     btrfs_search_header_objectid(sh)
-			     < BTRFS_FIRST_FREE_OBJECTID) ||
-			    btrfs_search_header_objectid(sh)
-			    > BTRFS_LAST_FREE_OBJECTID) {
-				goto skip;
-			}
-
-			if (btrfs_search_header_type(sh)
-			    == BTRFS_ROOT_ITEM_KEY) {
-				/* older kernels don't have uuids+times */
-				if (btrfs_search_header_len(sh)
-				    < sizeof(root_item)) {
-					root_item_valid = 0;
-					goto skip;
-				}
-				root_item_ptr = (struct btrfs_root_item *)
-						(args.buf + off);
-				memcpy(&root_item, root_item_ptr,
-						sizeof(root_item));
-				root_item_valid = 1;
-			} else if (btrfs_search_header_type(sh)
-				   == BTRFS_ROOT_BACKREF_KEY ||
-				   root_item_valid) {
-				char path_buf[PATH_MAX];
-				char *path;
-
-				if (!root_item_valid)
-					goto skip;
-
-				ret = btrfs_subvolid_resolve(mnt_fd, path_buf,
-						sizeof(path_buf),
-						btrfs_search_header_objectid(sh));
-				if (ret < 0) {
-					errno = -ret;
-					fprintf(stderr, "ERROR: unable to "
-							"resolve path "
-							"for root %llu: %m\n",
-						btrfs_search_header_objectid(sh));
-					goto out;
-				}
-				path = strdup(path_buf);
-
-				si = calloc(1, sizeof(*si));
-				si->root_id = btrfs_search_header_objectid(sh);
-				memcpy(si->uuid, root_item.uuid,
-						BTRFS_UUID_SIZE);
-				memcpy(si->parent_uuid, root_item.parent_uuid,
-						BTRFS_UUID_SIZE);
-				memcpy(si->received_uuid,
-						root_item.received_uuid,
-						BTRFS_UUID_SIZE);
-				si->ctransid = btrfs_root_ctransid(&root_item);
-				si->otransid = btrfs_root_otransid(&root_item);
-				si->stransid = btrfs_root_stransid(&root_item);
-				si->rtransid = btrfs_root_rtransid(&root_item);
-				si->path = path;
-				subvol_uuid_search_add(s, si);
-				root_item_valid = 0;
-			} else {
-				goto skip;
-			}
-
-skip:
-			off += btrfs_search_header_len(sh);
-
-			/*
-			 * record the mins in sk so we can make sure the
-			 * next search doesn't repeat this root
-			 */
-			sk->min_objectid = btrfs_search_header_objectid(sh);
-			sk->min_offset = btrfs_search_header_offset(sh);
-			sk->min_type = btrfs_search_header_type(sh);
-		}
-		sk->nr_items = 4096;
-		if (sk->min_offset < (u64)-1)
-			sk->min_offset++;
-		else if (sk->min_objectid < (u64)-1) {
-			sk->min_objectid++;
-			sk->min_offset = 0;
-			sk->min_type = 0;
-		} else
-			break;
-	}
-
-out:
-	return ret;
-}
-
-void subvol_uuid_search_finit(struct subvol_uuid_search *s)
-{
-	struct rb_root *root = &s->root_id_subvols;
-	struct rb_node *node;
-
-	if (!s->uuid_tree_existed)
-		return;
-
-	while ((node = rb_first(root))) {
-		struct subvol_info *entry =
-			rb_entry(node, struct subvol_info, rb_root_id_node);
-
-		free(entry->path);
-		rb_erase(node, root);
-		free(entry);
-	}
-
-	s->root_id_subvols = RB_ROOT;
-	s->local_subvols = RB_ROOT;
-	s->received_subvols = RB_ROOT;
-	s->path_subvols = RB_ROOT;
-}
-#else
 int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
 {
 	s->mnt_fd = mnt_fd;
@@ -755,4 +380,3 @@ int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
 void subvol_uuid_search_finit(struct subvol_uuid_search *s)
 {
 }
-#endif
diff --git a/common/send-utils.h b/common/send-utils.h
index 06c249e0..363e2483 100644
--- a/common/send-utils.h
+++ b/common/send-utils.h
@@ -23,12 +23,6 @@
 #include "kernel-shared/ctree.h"
 #include "kernel-lib/rbtree.h"
 
-/*
- * Compatibility code for kernels < 3.12; the UUID tree is not available there
- * and we have to do the slow search. This should be deprecated someday.
- */
-#define BTRFS_COMPAT_SEND_NO_UUID_TREE 1
-
 enum subvol_search_type {
 	subvol_search_by_root_id,
 	subvol_search_by_uuid,
@@ -37,13 +31,6 @@ enum subvol_search_type {
 };
 
 struct subvol_info {
-#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
-	struct rb_node rb_root_id_node;
-	struct rb_node rb_local_node;
-	struct rb_node rb_received_node;
-	struct rb_node rb_path_node;
-#endif
-
 	u64 root_id;
 	u8 uuid[BTRFS_UUID_SIZE];
 	u8 parent_uuid[BTRFS_UUID_SIZE];
@@ -58,14 +45,6 @@ struct subvol_info {
 
 struct subvol_uuid_search {
 	int mnt_fd;
-#ifdef BTRFS_COMPAT_SEND_NO_UUID_TREE
-	int uuid_tree_existed;
-
-	struct rb_root root_id_subvols;
-	struct rb_root local_subvols;
-	struct rb_root received_subvols;
-	struct rb_root path_subvols;
-#endif
 };
 
 int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s);