extent-io.c 2.3 KB

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  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. #include "btrfs.h"
  8. #include <malloc.h>
  9. #include <memalign.h>
  10. u64 btrfs_read_extent_inline(struct btrfs_path *path,
  11. struct btrfs_file_extent_item *extent, u64 offset,
  12. u64 size, char *out)
  13. {
  14. u32 clen, dlen, orig_size = size, res;
  15. const char *cbuf;
  16. char *dbuf;
  17. const int data_off = offsetof(struct btrfs_file_extent_item,
  18. disk_bytenr);
  19. clen = btrfs_path_item_size(path) - data_off;
  20. cbuf = (const char *) extent + data_off;
  21. dlen = extent->ram_bytes;
  22. if (offset > dlen)
  23. return -1ULL;
  24. if (size > dlen - offset)
  25. size = dlen - offset;
  26. if (extent->compression == BTRFS_COMPRESS_NONE) {
  27. memcpy(out, cbuf + offset, size);
  28. return size;
  29. }
  30. if (dlen > orig_size) {
  31. dbuf = malloc(dlen);
  32. if (!dbuf)
  33. return -1ULL;
  34. } else {
  35. dbuf = out;
  36. }
  37. res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen);
  38. if (res == -1 || res != dlen)
  39. goto err;
  40. if (dlen > orig_size) {
  41. memcpy(out, dbuf + offset, size);
  42. free(dbuf);
  43. } else if (offset) {
  44. memmove(out, dbuf + offset, size);
  45. }
  46. return size;
  47. err:
  48. if (dlen > orig_size)
  49. free(dbuf);
  50. return -1ULL;
  51. }
  52. u64 btrfs_read_extent_reg(struct btrfs_path *path,
  53. struct btrfs_file_extent_item *extent, u64 offset,
  54. u64 size, char *out)
  55. {
  56. u64 physical, clen, dlen, orig_size = size;
  57. u32 res;
  58. char *cbuf, *dbuf;
  59. clen = extent->disk_num_bytes;
  60. dlen = extent->num_bytes;
  61. if (offset > dlen)
  62. return -1ULL;
  63. if (size > dlen - offset)
  64. size = dlen - offset;
  65. physical = btrfs_map_logical_to_physical(extent->disk_bytenr);
  66. if (physical == -1ULL)
  67. return -1ULL;
  68. if (extent->compression == BTRFS_COMPRESS_NONE) {
  69. physical += extent->offset + offset;
  70. if (!btrfs_devread(physical, size, out))
  71. return -1ULL;
  72. return size;
  73. }
  74. cbuf = malloc_cache_aligned(dlen > size ? clen + dlen : clen);
  75. if (!cbuf)
  76. return -1ULL;
  77. if (dlen > orig_size)
  78. dbuf = cbuf + clen;
  79. else
  80. dbuf = out;
  81. if (!btrfs_devread(physical, clen, cbuf))
  82. goto err;
  83. res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen);
  84. if (res == -1)
  85. goto err;
  86. if (dlen > orig_size)
  87. memcpy(out, dbuf + offset, size);
  88. else
  89. memmove(out, dbuf + offset, size);
  90. free(cbuf);
  91. return res;
  92. err:
  93. free(cbuf);
  94. return -1ULL;
  95. }