fs/btrfs/btrfs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * BTRFS filesystem implementation for U-Boot
   4  *
   5  * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
   6  */
   7
   8 #include <config.h>
   9 #include <malloc.h>
  10 #include <uuid.h>
  11 #include <linux/time.h>
  12 #include "btrfs.h"
  13 #include "crypto/hash.h"
  14 #include "disk-io.h"
  15
  16 struct btrfs_fs_info *current_fs_info;
  17
  18 static int show_dir(struct btrfs_root *root, struct extent_buffer *eb,
  19                     struct btrfs_dir_item *di)
  20 {
  21         struct btrfs_fs_info *fs_info = root->fs_info;
  22         struct btrfs_inode_item ii;
  23         struct btrfs_key key;
  24         static const char* dir_item_str[] = {
  25                 [BTRFS_FT_REG_FILE]     = "   ",
  26                 [BTRFS_FT_DIR]          = "DIR",
  27                 [BTRFS_FT_CHRDEV]       = "CHR",
  28                 [BTRFS_FT_BLKDEV]       = "BLK",
  29                 [BTRFS_FT_FIFO]         = "FIF",
  30                 [BTRFS_FT_SOCK]         = "SCK",
  31                 [BTRFS_FT_SYMLINK]      = "SYM",
  32         };
  33         u8 type = btrfs_dir_type(eb, di);
  34         char namebuf[BTRFS_NAME_LEN];
  35         char *target = NULL;
  36         char filetime[32];
  37         time_t mtime;
  38         int ret = 0;
  39
  40         /* skip XATTRs in directory listing */
  41         if (type == BTRFS_FT_XATTR)
  42                 return 0;
  43
  44         btrfs_dir_item_key_to_cpu(eb, di, &key);
  45
  46         if (key.type == BTRFS_ROOT_ITEM_KEY) {
  47                 struct btrfs_root *subvol;
  48
  49                 /* It's a subvolume, get its mtime from root item */
  50                 subvol = btrfs_read_fs_root(fs_info, &key);
  51                 if (IS_ERR(subvol)) {
  52                         ret = PTR_ERR(subvol);
  53                         error("Can't find root %llu", key.objectid);
  54                         return ret;
  55                 }
  56                 mtime = btrfs_stack_timespec_sec(&subvol->root_item.otime);
  57         } else {
  58                 struct btrfs_path path;
  59
  60                 /* It's regular inode, get its mtime from inode item */
  61                 btrfs_init_path(&path);
  62                 ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
  63                 if (ret > 0)
  64                         ret = -ENOENT;
  65                 if (ret < 0) {
  66                         error("Can't find inode %llu", key.objectid);
  67                         btrfs_release_path(&path);
  68                         return ret;
  69                 }
  70                 read_extent_buffer(path.nodes[0], &ii,
  71                         btrfs_item_ptr_offset(path.nodes[0], path.slots[0]),
  72                         sizeof(ii));
  73                 btrfs_release_path(&path);
  74                 mtime = btrfs_stack_timespec_sec(&ii.mtime);
  75         }
  76         ctime_r(&mtime, filetime);
  77
  78         if (type == BTRFS_FT_SYMLINK) {
  79                 target = malloc(fs_info->sectorsize);
  80                 if (!target) {
  81                         error("Can't alloc memory for symlink %llu",
  82                                 key.objectid);
  83                         return -ENOMEM;
  84                 }
  85                 ret = btrfs_readlink(root, key.objectid, target);
  86                 if (ret < 0) {
  87                         error("Failed to read symlink %llu", key.objectid);
  88                         goto out;
  89                 }
  90                 target[ret] = '\0';
  91         }
  92
  93         if (type < ARRAY_SIZE(dir_item_str) && dir_item_str[type])
  94                 printf("<%s> ", dir_item_str[type]);
  95         else
  96                 printf("?%3u? ", type);
  97         if (type == BTRFS_FT_CHRDEV || type == BTRFS_FT_BLKDEV) {
  98                 ASSERT(key.type == BTRFS_INODE_ITEM_KEY);
  99                 printf("%4llu,%5llu  ", btrfs_stack_inode_rdev(&ii) >> 20,
 100                                 btrfs_stack_inode_rdev(&ii) & 0xfffff);
 101         } else {
 102                 if (key.type == BTRFS_INODE_ITEM_KEY)
 103                         printf("%10llu  ", btrfs_stack_inode_size(&ii));
 104                 else
 105                         printf("%10llu  ", 0ULL);
 106         }
 107
 108         read_extent_buffer(eb, namebuf, (unsigned long)(di + 1),
 109                            btrfs_dir_name_len(eb, di));
 110         printf("%24.24s  %.*s", filetime, btrfs_dir_name_len(eb, di), namebuf);
 111         if (type == BTRFS_FT_SYMLINK)
 112                 printf(" -> %s", target ? target : "?");
 113         printf("\n");
 114 out:
 115         free(target);
 116         return ret;
 117 }
 118
 119 int btrfs_probe(struct blk_desc *fs_dev_desc,
 120                 struct disk_partition *fs_partition)
 121 {
 122         struct btrfs_fs_info *fs_info;
 123         int ret = -1;
 124
 125         btrfs_hash_init();
 126         fs_info = open_ctree_fs_info(fs_dev_desc, fs_partition);
 127         if (fs_info) {
 128                 current_fs_info = fs_info;
 129                 ret = 0;
 130         }
 131         return ret;
 132 }
 133
 134 int btrfs_ls(const char *path)
 135 {
 136         struct btrfs_fs_info *fs_info = current_fs_info;
 137         struct btrfs_root *root = fs_info->fs_root;
 138         u64 ino = BTRFS_FIRST_FREE_OBJECTID;
 139         u8 type;
 140         int ret;
 141
 142         ASSERT(fs_info);
 143         ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
 144                                 path, &root, &ino, &type, 40);
 145         if (ret < 0) {
 146                 printf("Cannot lookup path %s\n", path);
 147                 return ret;
 148         }
 149
 150         if (type != BTRFS_FT_DIR) {
 151                 error("Not a directory: %s", path);
 152                 return -ENOENT;
 153         }
 154         ret = btrfs_iter_dir(root, ino, show_dir);
 155         if (ret < 0) {
 156                 error("An error occurred while listing directory %s", path);
 157                 return ret;
 158         }
 159         return 0;
 160 }
 161
 162 int btrfs_exists(const char *file)
 163 {
 164         struct btrfs_fs_info *fs_info = current_fs_info;
 165         struct btrfs_root *root;
 166         u64 ino;
 167         u8 type;
 168         int ret;
 169
 170         ASSERT(fs_info);
 171
 172         ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
 173                                 file, &root, &ino, &type, 40);
 174         if (ret < 0)
 175                 return 0;
 176
 177         if (type == BTRFS_FT_REG_FILE)
 178                 return 1;
 179         return 0;
 180 }
 181
 182 int btrfs_size(const char *file, loff_t *size)
 183 {
 184         struct btrfs_fs_info *fs_info = current_fs_info;
 185         struct btrfs_inode_item *ii;
 186         struct btrfs_root *root;
 187         struct btrfs_path path;
 188         struct btrfs_key key;
 189         u64 ino;
 190         u8 type;
 191         int ret;
 192
 193         ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
 194                                 file, &root, &ino, &type, 40);
 195         if (ret < 0) {
 196                 printf("Cannot lookup file %s\n", file);
 197                 return ret;
 198         }
 199         if (type != BTRFS_FT_REG_FILE) {
 200                 printf("Not a regular file: %s\n", file);
 201                 return -ENOENT;
 202         }
 203         btrfs_init_path(&path);
 204         key.objectid = ino;
 205         key.type = BTRFS_INODE_ITEM_KEY;
 206         key.offset = 0;
 207
 208         ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
 209         if (ret < 0) {
 210                 printf("Cannot lookup ino %llu\n", ino);
 211                 return ret;
 212         }
 213         if (ret > 0) {
 214                 printf("Ino %llu does not exist\n", ino);
 215                 ret = -ENOENT;
 216                 goto out;
 217         }
 218         ii = btrfs_item_ptr(path.nodes[0], path.slots[0],
 219                             struct btrfs_inode_item);
 220         *size = btrfs_inode_size(path.nodes[0], ii);
 221 out:
 222         btrfs_release_path(&path);
 223         return ret;
 224 }
 225
 226 int btrfs_read(const char *file, void *buf, loff_t offset, loff_t len,
 227                loff_t *actread)
 228 {
 229         struct btrfs_fs_info *fs_info = current_fs_info;
 230         struct btrfs_root *root;
 231         loff_t real_size = 0;
 232         u64 ino;
 233         u8 type;
 234         int ret;
 235
 236         ASSERT(fs_info);
 237         ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
 238                                 file, &root, &ino, &type, 40);
 239         if (ret < 0) {
 240                 error("Cannot lookup file %s", file);
 241                 return ret;
 242         }
 243
 244         if (type != BTRFS_FT_REG_FILE) {
 245                 error("Not a regular file: %s", file);
 246                 return -EINVAL;
 247         }
 248
 249         if (!len) {
 250                 ret = btrfs_size(file, &real_size);
 251                 if (ret < 0) {
 252                         error("Failed to get inode size: %s", file);
 253                         return ret;
 254                 }
 255                 len = real_size;
 256         }
 257
 258         if (len > real_size - offset)
 259                 len = real_size - offset;
 260
 261         ret = btrfs_file_read(root, ino, offset, len, buf);
 262         if (ret < 0) {
 263                 error("An error occurred while reading file %s", file);
 264                 return ret;
 265         }
 266
 267         *actread = len;
 268         return 0;
 269 }
 270
 271 void btrfs_close(void)
 272 {
 273         if (current_fs_info) {
 274                 close_ctree_fs_info(current_fs_info);
 275                 current_fs_info = NULL;
 276         }
 277 }
 278
 279 int btrfs_uuid(char *uuid_str)
 280 {
 281 #ifdef CONFIG_LIB_UUID
 282         if (current_fs_info)
 283                 uuid_bin_to_str(current_fs_info->super_copy->fsid, uuid_str,
 284                                 UUID_STR_FORMAT_STD);
 285         return 0;
 286 #endif
 287         return -ENOSYS;
 288 }