{"id":17639,"date":"2024-11-18T10:00:46","date_gmt":"2024-11-18T02:00:46","guid":{"rendered":"https:\/\/fwq.ai\/blog\/17639\/"},"modified":"2024-11-18T10:00:46","modified_gmt":"2024-11-18T02:00:46","slug":"linux%e4%b8%8bext2%e6%96%87%e4%bb%b6%e7%b3%bb%e7%bb%9f%e7%9a%84%e7%89%a9%e7%90%86%e7%bb%93%e6%9e%84%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/17639\/","title":{"rendered":"Linux\u4e0bext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\u8be6\u89e3"},"content":{"rendered":"

\"Linux\u4e0bext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\u8be6\u89e3\u63d2\u56fe\"<\/p>\n

Linux\u4e0bext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\u8be6\u89e3<\/strong><\/p>\n

\u5728Linux\u7cfb\u7edf\u4e2d\uff0cext2\u662f\u4e00\u79cd\u5e38\u7528\u7684\u6587\u4ef6\u7cfb\u7edf\u7c7b\u578b\uff0c\u5b83\u662f\u4e00\u79cd\u8f83\u4e3a\u7b80\u5355\u800c\u53c8\u9ad8\u6548\u7684\u6587\u4ef6\u7cfb\u7edf\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8ext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\uff0c\u5305\u62ec\u8d85\u7ea7\u5757\u3001\u7ec4\u63cf\u8ff0\u7b26\u3001inode\u8868\u3001\u6570\u636e\u5757\u7b49\uff0c\u540c\u65f6\u4f1a\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u6765\u5e2e\u52a9\u8bfb\u8005\u66f4\u597d\u5730\u7406\u89e3\u3002<\/p>\n

1. \u8d85\u7ea7\u5757\uff08Super Block\uff09<\/h3>\n

\u8d85\u7ea7\u5757<\/strong>\u662fext2\u6587\u4ef6\u7cfb\u7edf\u4e2d\u6700\u91cd\u8981\u7684\u6570\u636e\u7ed3\u6784\u4e4b\u4e00\uff0c\u5b83\u5b58\u50a8\u7740\u6587\u4ef6\u7cfb\u7edf\u7684\u6574\u4f53\u4fe1\u606f\uff0c\u5982inode\u603b\u6570\u3001\u6570\u636e\u5757\u603b\u6570\u3001\u6bcf\u7ec4\u7684inode\u6570\u91cf\u3001\u6570\u636e\u5757\u6570\u91cf\u7b49\u3002\u4ee5\u4e0b\u662f\u8d85\u7ea7\u5757\u7684\u7ed3\u6784\u793a\u4f8b\uff1a<\/p>\n

struct ext2_super_block {\n    __le32 s_inodes_count; \/\/ inode\u603b\u6570\n    __le32 s_blocks_count; \/\/ \u6570\u636e\u5757\u603b\u6570\n    __le32 s_inodes_per_group; \/\/ \u6bcf\u7ec4\u7684inode\u6570\u91cf\n    __le32 s_blocks_per_group; \/\/ \u6bcf\u7ec4\u7684\u6570\u636e\u5757\u6570\u91cf\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u7701\u7565\n};<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
2. \u7ec4\u63cf\u8ff0\u7b26\uff08Group Descriptor\uff09<\/h3>\n
\u7ec4\u63cf\u8ff0\u7b26<\/strong>\u5b58\u50a8\u7740\u6bcf\u4e2a\u7ec4\uff08group\uff09\u7684\u5143\u6570\u636e\u4fe1\u606f\uff0c\u5305\u62ecinode\u4f4d\u56fe\u3001\u6570\u636e\u5757\u4f4d\u56fe\u3001inode\u8868\u8d77\u59cb\u5757\u53f7\u3001\u6570\u636e\u5757\u8d77\u59cb\u5757\u53f7\u7b49\u3002\u4ee5\u4e0b\u662f\u7ec4\u63cf\u8ff0\u7b26\u7684\u7ed3\u6784\u793a\u4f8b\uff1a<\/p>\n
struct ext2_group_desc {\n    __le32 bg_inode_bitmap; \/\/ inode\u4f4d\u56fe\u5757\u53f7\n    __le32 bg_block_bitmap; \/\/ \u6570\u636e\u5757\u4f4d\u56fe\u5757\u53f7\n    __le32 bg_inode_table; \/\/ inode\u8868\u7684\u8d77\u59cb\u5757\u53f7\n    __le16 bg_free_blocks_count; \/\/ \u7a7a\u95f2\u6570\u636e\u5757\u6570\u91cf\n    __le16 bg_free_inodes_count; \/\/ \u7a7a\u95f2inode\u6570\u91cf\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u7701\u7565\n};<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
3. inode\u8868\uff08Inode Table\uff09<\/h3>\n
inode\u8868<\/strong>\u5b58\u50a8\u7740\u6587\u4ef6\u6216\u76ee\u5f55\u7684\u5143\u6570\u636e\u4fe1\u606f\uff0c\u5982\u6587\u4ef6\u5927\u5c0f\u3001\u6743\u9650\u3001\u6240\u6709\u8005\u3001\u65f6\u95f4\u6233\u7b49\u3002\u6bcf\u4e2a\u6587\u4ef6\u6216\u76ee\u5f55\u90fd\u5bf9\u5e94\u4e00\u4e2ainode\u8868\u4e2d\u7684\u7d22\u5f15\u8282\u70b9\uff08inode\uff09\u3002\u4ee5\u4e0b\u662finode\u8868\u4e2d\u6bcf\u4e2ainode\u7684\u7ed3\u6784\u793a\u4f8b\uff1a<\/p>\n
struct ext2_inode {\n    __le16 i_mode; \/\/ \u6587\u4ef6\u7c7b\u578b\u548c\u6743\u9650\n    __le32 i_size; \/\/ \u6587\u4ef6\u5927\u5c0f\n    __le32 i_blocks; \/\/ \u6570\u636e\u5757\u6570\u91cf\n    __le32 i_block[15]; \/\/ \u6570\u636e\u5757\u53f7\u6570\u7ec4\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u7701\u7565\n};<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
4. \u6570\u636e\u5757\uff08Data Block\uff09<\/h3>\n
\u6570\u636e\u5757<\/strong>\u662f\u5b58\u50a8\u5b9e\u9645\u6587\u4ef6\u5185\u5bb9\u7684\u5730\u65b9\uff0cext2\u6587\u4ef6\u7cfb\u7edf\u91c7\u7528\u95f4\u63a5\u5bfb\u5740\u7684\u65b9\u5f0f\u6765\u7ba1\u7406\u6570\u636e\u5757\u3002\u6570\u636e\u5757\u7531\u82e5\u5e72\u4e2a\u6247\u533a\u7ec4\u6210\uff0c\u6247\u533a\u662f\u6587\u4ef6\u7cfb\u7edf\u4e2d\u6700\u5c0f\u7684\u5b58\u50a8\u5355\u4f4d\u3002\u4ee5\u4e0b\u662f\u6570\u636e\u5757\u7684\u7ed3\u6784\u793a\u4f8b\uff1a<\/p>\n
struct ext2_data_block {\n    char data[1024]; \/\/ \u6570\u636e\u5757\u5927\u5c0f\u4e3a1KB\n};<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
5. \u4ee3\u7801\u793a\u4f8b<\/h3>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u793a\u4f8b\u7a0b\u5e8f\uff0c\u7528\u4e8e\u8bfb\u53d6ext2\u6587\u4ef6\u7cfb\u7edf\u4e2d\u7684\u8d85\u7ea7\u5757\u4fe1\u606f\uff1a<\/p>\n
#include <stdio.h>\n#include <fcntl.h>\n#include <ext2fs>\n\nint main() {\n    int fd = open(\"\/dev\/sda1\", O_RDONLY);\n    if (fd == -1) {\n        perror(\"open\");\n        return 1;\n    }\n\n    struct ext2_super_block sb;\n    lseek(fd, 1024, SEEK_SET); \/\/ \u8d85\u7ea7\u5757\u4f4d\u4e8e\u504f\u79fb1024\u5b57\u8282\u5904\n    read(fd, &amp;sb, sizeof(sb));\n\n    printf(\"Inode\u603b\u6570\uff1a%u\n\", sb.s_inodes_count);\n    printf(\"\u6570\u636e\u5757\u603b\u6570\uff1a%u\n\", sb.s_blocks_count);\n    \/\/ \u8f93\u51fa\u5176\u4ed6\u8d85\u7ea7\u5757\u4fe1\u606f\n\n    close(fd);\n    return 0;\n}<\/ext2fs><\/fcntl.h><\/stdio.h><\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u7ed3\u8bed<\/h3>\n
\u672c\u6587\u5bf9Linux\u4e0bext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\u8fdb\u884c\u4e86\u8be6\u7ec6\u89e3\u6790\uff0c\u5305\u62ec\u8d85\u7ea7\u5757\u3001\u7ec4\u63cf\u8ff0\u7b26\u3001inode\u8868\u548c\u6570\u636e\u5757\u7b49\u91cd\u8981\u90e8\u5206\uff0c\u5e76\u63d0\u4f9b\u4e86\u76f8\u5173\u4ee3\u7801\u793a\u4f8b\u5e2e\u52a9\u8bfb\u8005\u66f4\u52a0\u6df1\u5165\u5730\u4e86\u89e3ext2\u6587\u4ef6\u7cfb\u7edf\u7684\u5185\u90e8\u5b9e\u73b0\u3002\u5e0c\u671b\u672c\u6587\u80fd\u591f\u5bf9\u8bfb\u8005\u6709\u6240\u5e2e\u52a9\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662fLinux\u4e0bext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\u8be6\u89e3\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
Linux\u4e0bext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\u8be6\u89e3 \u5728Linux\u7cfb\u7edf\u4e2d\uff0cext2\u662f\u4e00\u79cd\u5e38\u7528\u7684\u6587\u4ef6\u7cfb\u7edf\u7c7b\u578b\uff0c\u5b83\u662f\u4e00\u79cd\u8f83\u4e3a\u7b80\u5355\u800c\u53c8\u9ad8\u6548\u7684\u6587\u4ef6\u7cfb\u7edf\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8ext2\u6587\u4ef6\u7cfb\u7edf\u7684\u7269\u7406\u7ed3\u6784\uff0c\u5305\u62ec\u8d85\u7ea7\u5757\u3001\u7ec4\u63cf\u8ff0\u7b26\u3001inode\u8868\u3001\u6570\u636e\u5757\u7b49\uff0c\u540c\u65f6\u4f1a\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u6765\u5e2e\u52a9\u8bfb\u8005\u66f4\u597d\u5730\u7406\u89e3\u3002 1. \u8d85\u7ea7\u5757\uff08Super Block\uff09 \u8d85\u7ea7\u5757\u662fext2\u6587\u4ef6\u7cfb\u7edf\u4e2d\u6700\u91cd\u8981\u7684\u6570\u636e\u7ed3\u6784\u4e4b\u4e00\uff0c\u5b83\u5b58\u50a8\u7740\u6587\u4ef6\u7cfb\u7edf\u7684\u6574\u4f53\u4fe1\u606f\uff0c\u5982inode\u603b\u6570\u3001\u6570\u636e\u5757\u603b\u6570\u3001\u6bcf\u7ec4\u7684inode\u6570\u91cf\u3001\u6570\u636e\u5757\u6570\u91cf\u7b49\u3002\u4ee5\u4e0b\u662f\u8d85\u7ea7\u5757\u7684\u7ed3\u6784\u793a\u4f8b\uff1a struct ext2_super_block { __le32 s_inodes_count; \/\/ inode\u603b\u6570 __le32 s_blocks_count; \/\/ \u6570\u636e\u5757\u603b\u6570 __le32 s_inodes_per_group; \/\/ \u6bcf\u7ec4\u7684inode\u6570\u91cf __le32 s_blocks_per_group; \/\/ \u6bcf\u7ec4\u7684\u6570\u636e\u5757\u6570\u91cf \/\/ \u5176\u4ed6\u5b57\u6bb5\u7701\u7565 }; \u767b\u5f55\u540e\u590d\u5236 2. \u7ec4\u63cf\u8ff0\u7b26\uff08Group Descriptor\uff09 \u7ec4\u63cf\u8ff0\u7b26\u5b58\u50a8\u7740\u6bcf\u4e2a\u7ec4\uff08group\uff09\u7684\u5143\u6570\u636e\u4fe1\u606f\uff0c\u5305\u62ecinode\u4f4d\u56fe\u3001\u6570\u636e\u5757\u4f4d\u56fe\u3001inode\u8868\u8d77\u59cb\u5757\u53f7\u3001\u6570\u636e\u5757\u8d77\u59cb\u5757\u53f7\u7b49\u3002\u4ee5\u4e0b\u662f\u7ec4\u63cf\u8ff0\u7b26\u7684\u7ed3\u6784\u793a\u4f8b\uff1a struct ext2_group_desc { __le32 bg_inode_bitmap; \/\/ inode\u4f4d\u56fe\u5757\u53f7 __le32 bg_block_bitmap; \/\/ \u6570\u636e\u5757\u4f4d\u56fe\u5757\u53f7 __le32 bg_inode_table; \/\/ inode\u8868\u7684\u8d77\u59cb\u5757\u53f7 __le16 bg_free_blocks_count; \/\/ \u7a7a\u95f2\u6570\u636e\u5757\u6570\u91cf __le16 bg_free_inodes_count; \/\/ […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-17639","post","type-post","status-publish","format-standard","hentry","category-os"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/17639","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=17639"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/17639\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=17639"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=17639"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=17639"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}