btrfs-progs: check/lowmem: Fix false alert of data extent backref lost for snapshot
[platform/upstream/btrfs-progs.git] / send-utils.c
index 874f8a5..b5289e7 100644 (file)
@@ -20,6 +20,8 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <uuid/uuid.h>
+#include <limits.h>
+#include <errno.h>
 
 #include "ctree.h"
 #include "send-utils.h"
@@ -81,8 +83,7 @@ static int btrfs_read_root_item_raw(int mnt_fd, u64 root_id, size_t buf_len,
                ret = ioctl(mnt_fd, BTRFS_IOC_TREE_SEARCH, &args);
                if (ret < 0) {
                        fprintf(stderr,
-                               "ERROR: can't perform the search - %s\n",
-                               strerror(errno));
+                               "ERROR: can't perform the search - %m\n");
                        return 0;
                }
                /* the ioctl returns the number of item it found in nr_items */
@@ -97,25 +98,25 @@ static int btrfs_read_root_item_raw(int mnt_fd, u64 root_id, size_t buf_len,
 
                        off += sizeof(*sh);
                        item = (struct btrfs_root_item *)(args.buf + off);
-                       off += sh->len;
+                       off += btrfs_search_header_len(sh);
 
-                       sk->min_objectid = sh->objectid;
-                       sk->min_type = sh->type;
-                       sk->min_offset = sh->offset;
+                       sk->min_objectid = btrfs_search_header_objectid(sh);
+                       sk->min_type = btrfs_search_header_type(sh);
+                       sk->min_offset = btrfs_search_header_offset(sh);
 
-                       if (sh->objectid > root_id)
+                       if (btrfs_search_header_objectid(sh) > root_id)
                                break;
 
-                       if (sh->objectid == root_id &&
-                           sh->type == BTRFS_ROOT_ITEM_KEY) {
-                               if (sh->len > buf_len) {
+                       if (btrfs_search_header_objectid(sh) == root_id &&
+                           btrfs_search_header_type(sh) == BTRFS_ROOT_ITEM_KEY) {
+                               if (btrfs_search_header_len(sh) > buf_len) {
                                        /* btrfs-progs is too old for kernel */
                                        fprintf(stderr,
                                                "ERROR: buf for read_root_item_raw() is too small, get newer btrfs tools!\n");
                                        return -EOVERFLOW;
                                }
-                               memcpy(buf, item, sh->len);
-                               *read_len = sh->len;
+                               memcpy(buf, item, btrfs_search_header_len(sh));
+                               *read_len = btrfs_search_header_len(sh);
                                found = 1;
                        }
                }
@@ -159,6 +160,73 @@ 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)
@@ -196,10 +264,10 @@ static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
        search_arg.key.max_transid = (u64)-1;
        search_arg.key.nr_items = 1;
        ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_arg);
-       if (ret) {
+       if (ret < 0) {
                fprintf(stderr,
-                       "ioctl(BTRFS_IOC_TREE_SEARCH, subvol_id %llu) ret=%d, error: %s\n",
-                       (unsigned long long)subvol_id, ret, strerror(errno));
+                       "ioctl(BTRFS_IOC_TREE_SEARCH, subvol_id %llu) ret=%d, error: %m\n",
+                       (unsigned long long)subvol_id, ret);
                return ret;
        }
 
@@ -211,11 +279,12 @@ static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
        }
        search_header = (struct btrfs_ioctl_search_header *)search_arg.buf;
        backref_item = (struct btrfs_root_ref *)(search_header + 1);
-       if (search_header->offset != BTRFS_FS_TREE_OBJECTID) {
+       if (btrfs_search_header_offset(search_header)
+           != BTRFS_FS_TREE_OBJECTID) {
                int sub_ret;
 
                sub_ret = btrfs_subvolid_resolve_sub(fd, path, path_len,
-                                                    search_header->offset);
+                               btrfs_search_header_offset(search_header));
                if (sub_ret)
                        return sub_ret;
                if (*path_len < 1)
@@ -229,14 +298,15 @@ static int btrfs_subvolid_resolve_sub(int fd, char *path, size_t *path_len,
                int len;
 
                memset(&ino_lookup_arg, 0, sizeof(ino_lookup_arg));
-               ino_lookup_arg.treeid = search_header->offset;
+               ino_lookup_arg.treeid =
+                       btrfs_search_header_offset(search_header);
                ino_lookup_arg.objectid =
                        btrfs_stack_root_ref_dirid(backref_item);
                ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_lookup_arg);
-               if (ret) {
+               if (ret < 0) {
                        fprintf(stderr,
-                               "ioctl(BTRFS_IOC_INO_LOOKUP) ret=%d, error: %s\n",
-                               ret, strerror(errno));
+                               "ioctl(BTRFS_IOC_INO_LOOKUP) ret=%d, error: %m\n",
+                               ret);
                        return ret;
                }
 
@@ -255,6 +325,104 @@ 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)
 {
@@ -263,16 +431,35 @@ 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,
                                       const char *path,
                                       enum subvol_search_type type)
 {
+       struct subvol_info *si;
+
+       si = subvol_uuid_search2(s, root_id, uuid, transid, path, type);
+       if (IS_ERR(si))
+               return NULL;
+       return si;
+}
+
+struct subvol_info *subvol_uuid_search2(struct subvol_uuid_search *s,
+                                      u64 root_id, const u8 *uuid, u64 transid,
+                                      const char *path,
+                                      enum subvol_search_type type)
+{
        int ret = 0;
        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,
@@ -299,6 +486,10 @@ struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,
                goto out;
 
        info = calloc(1, sizeof(*info));
+       if (!info) {
+               ret = -ENOMEM;
+               goto out;
+       }
        info->root_id = root_id;
        memcpy(info->uuid, root_item.uuid, BTRFS_UUID_SIZE);
        memcpy(info->received_uuid, root_item.received_uuid, BTRFS_UUID_SIZE);
@@ -309,22 +500,234 @@ struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,
        info->rtransid = btrfs_root_rtransid(&root_item);
        if (type == subvol_search_by_path) {
                info->path = strdup(path);
+               if (!info->path) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
        } else {
-               info->path = malloc(BTRFS_PATH_NAME_MAX);
+               info->path = malloc(PATH_MAX);
+               if (!info->path) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
                ret = btrfs_subvolid_resolve(s->mnt_fd, info->path,
-                                            BTRFS_PATH_NAME_MAX, root_id);
+                                            PATH_MAX, root_id);
        }
 
 out:
-       if (ret && info) {
-               free(info->path);
-               free(info);
-               info = NULL;
+       if (ret) {
+               if (info) {
+                       free(info->path);
+                       free(info);
+               }
+               return ERR_PTR(ret);
        }
 
        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;
+       char *path;
+
+       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) {
+                               if (!root_item_valid)
+                                       goto skip;
+
+                               path = btrfs_list_path_for_root(mnt_fd,
+                                       btrfs_search_header_objectid(sh));
+                               if (!path)
+                                       path = strdup("");
+                               if (IS_ERR(path)) {
+                                       ret = PTR_ERR(path);
+                                       fprintf(stderr, "ERROR: unable to "
+                                                       "resolve path "
+                                                       "for root %llu\n",
+                                               btrfs_search_header_objectid(sh));
+                                       goto out;
+                               }
+
+                               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;
@@ -335,27 +738,45 @@ int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
 void subvol_uuid_search_finit(struct subvol_uuid_search *s)
 {
 }
+#endif
 
-char *path_cat(const char *p1, const char *p2)
+int path_cat_out(char *out, const char *p1, const char *p2)
 {
        int p1_len = strlen(p1);
        int p2_len = strlen(p2);
-       char *new = malloc(p1_len + p2_len + 2);
+
+       if (p1_len + p2_len + 2 >= PATH_MAX)
+               return -ENAMETOOLONG;
 
        if (p1_len && p1[p1_len - 1] == '/')
                p1_len--;
        if (p2_len && p2[p2_len - 1] == '/')
                p2_len--;
-       sprintf(new, "%.*s/%.*s", p1_len, p1, p2_len, p2);
+       sprintf(out, "%.*s/%.*s", p1_len, p1, p2_len, p2);
+
+       return 0;
+}
+
+__attribute__((deprecated))
+char *path_cat(const char *p1, const char *p2)
+{
+       int p1_len = strlen(p1);
+       int p2_len = strlen(p2);
+       char *new = malloc(p1_len + p2_len + 2);
+
+       path_cat_out(new, p1, p2);
+
        return new;
 }
 
-char *path_cat3(const char *p1, const char *p2, const char *p3)
+int path_cat3_out(char *out, const char *p1, const char *p2, const char *p3)
 {
        int p1_len = strlen(p1);
        int p2_len = strlen(p2);
        int p3_len = strlen(p3);
-       char *new = malloc(p1_len + p2_len + p3_len + 3);
+
+       if (p1_len + p2_len + p3_len + 3 >= PATH_MAX)
+               return -ENAMETOOLONG;
 
        if (p1_len && p1[p1_len - 1] == '/')
                p1_len--;
@@ -363,6 +784,20 @@ char *path_cat3(const char *p1, const char *p2, const char *p3)
                p2_len--;
        if (p3_len && p3[p3_len - 1] == '/')
                p3_len--;
-       sprintf(new, "%.*s/%.*s/%.*s", p1_len, p1, p2_len, p2, p3_len, p3);
+       sprintf(out, "%.*s/%.*s/%.*s", p1_len, p1, p2_len, p2, p3_len, p3);
+
+       return 0;
+}
+
+__attribute__((deprecated))
+char *path_cat3(const char *p1, const char *p2, const char *p3)
+{
+       int p1_len = strlen(p1);
+       int p2_len = strlen(p2);
+       int p3_len = strlen(p3);
+       char *new = malloc(p1_len + p2_len + p3_len + 3);
+
+       path_cat3_out(new, p1, p2, p3);
+
        return new;
 }