{"id":54,"date":"2023-03-16T00:05:22","date_gmt":"2023-03-15T16:05:22","guid":{"rendered":"http:\/\/fudong.tech\/?p=54"},"modified":"2023-03-16T00:05:22","modified_gmt":"2023-03-15T16:05:22","slug":"scsi-%e5%91%bd%e4%bb%a4-scsi_cmnd%e7%9a%84%e7%94%9f%e5%91%bd%e5%91%a8%e6%9c%9f-%e5%9f%ba%e4%ba%8e-linux-kernel-v4-0","status":"publish","type":"post","link":"http:\/\/fudong.tech\/?p=54","title":{"rendered":"SCSI \u547d\u4ee4 (scsi_cmnd)\u7684\u751f\u547d\u5468\u671f &#8212; \u57fa\u4e8e Linux kernel v4.0"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>            ==================================\n              SCSI \u547d\u4ee4 (scsi_cmnd)\u7684\u751f\u547d\u5468\u671f\n            ==================================\n\n         Rajat Jain &lt;rajatja@google.com&gt; \u4e8e 2015 \u5e74 5 \u6708 12 \u65e5<\/code><\/pre>\n\n\n\n<h2 class=\"has-small-font-size wp-block-heading\">\u7ffb\u8bd1\u4e8e 2023\u5e743\u670815\u65e5<\/h2>\n\n\n\n<p class=\"has-theme-palette-1-color has-text-color wp-block-paragraph\">|                                                     &amp;&amp;&amp; \u7ffb\u8bd1\u8bf4\u660e &amp;&amp;&amp;                                              |<br \/>| \u672c\u6587\u5bf9\u5e94\u7684\u539f\u6587\u5728\u4e4b\u524d\u5df2\u5411\u4e0a\u6e38\u793e\u533a\u63d0\u4ea4\uff0c\u4f46\u5728\u5f53\u524d\u7684\u4ee3\u7801\u4e2d\u5e76\u6ca1\u6709\u770b\u5230\u6b64\u6587\u6863\u3002 |<br \/>| \u63d0\u4ea4\u7684\u4fe1\u606f\u53ef\u53c2\u8003\u5982\u4e0b\u94fe\u63a5\uff1a                                                                                     |<br \/>| https:\/\/lwn.net\/Articles\/644318\/                                                                                 |<br \/>| https:\/\/lkml.org\/lkml\/2015\/5\/12\/853                                                                          |<br \/>| \u6216\u53ef\u53c2\u89c1 http:\/\/fudong.tech\/?p=52 \u4e2d\u622a\u53d6\u7684\u6b63\u6587                                                    |<br \/>|                                                                                                                                     |<br \/>| \u6587\u4e2d\u51fa\u73b0\u7684\u4e00\u4e9b\u540d\u8bcd\u8bf4\u660e\uff1a                                                                                        |<br \/>| \u4e3b\u673a\uff1a SCSI host\uff0c\u5373\u5bf9\u5e94\u7684\u4e3b\u673a\u9002\u914d\u5668\u3002\u53ef\u80fd\u4e3a RAID \u5361\u3001FC HBA \u7b49\u3002                |<br \/>|<br \/>| \u7f51\u9875\u56e0\u6a21\u677f\u6392\u7248\u539f\u56e0\uff0c\u53ef\u80fd\u5b58\u5728\u9519\u4e71\uff0c\u53ef\u53c2\u8003\u672b\u5c3e PDF \u6587\u4ef6<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\uff08\u672c\u6587\u6863\u5927\u81f4\u5339\u914d Linux \u5185\u6838 v4.0\uff09<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u6587\u6863\u63cf\u8ff0\u4e86 SCSI \u547d\u4ee4 (struct scsi_cmnd) \u751f\u547d\u5468\u671f\u7684\u5404\u4e2a\u9636\u6bb5\uff0c\u56e0\u4e3a\u5b83\u5305\u542b\u4e86 SCSI\u4e2d\u95f4\u5c42\u9a71\u52a8\u7a0b\u5e8f\uff08SCSI mid level driver\uff09\u7684\u4e0d\u540c\u90e8\u5206\u3002 \u5b83\u63cf\u8ff0\u4e86\u5728\u4ec0\u4e48\u6761\u4ef6\u4e0b\u4ee5\u53ca\u5982\u4f55\u4e2d\u6b62\u3001\u91cd\u8bd5\u6216\u5b89\u6392 scsi_cmnd \u8fdb\u884c\u9519\u8bef\u5904\u7406\uff0c\u5b83\u662f\u5982\u4f55\u6062\u590d\uff08recover\uff09\u7684\uff0c\u4ee5\u53ca SCSI\u4e2d\u95f4\u5c42\u9a71\u52a8\u7a0b\u5e8f\u901a\u5e38\u5982\u4f55\u5904\u7406\u5757\u8bf7\u6c42\u3002 \u5b83\u8be6\u7ec6\u4ecb\u7ecd\u4e86\u8c03\u7528\u54ea\u4e9b\u51fd\u6570\u4ee5\u53ca\u6bcf\u4e2a\u51fd\u6570\u7684\u7528\u9014\u7b49\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u7528\u4e00\u4e2a\u4f8b\u5b50\u6765\u5e2e\u52a9\u89e3\u91ca\uff0c\u5b83\u4ee5\u4e00\u4e2a scsi_cmnd \u7684\u4f8b\u5b50\u4e3a\u4f8b\uff0c\u5b83\u7ecf\u5386\u4e86\u8fd9\u4e00\u5207\u2014\u2014\u8d85\u65f6\uff08timeout\uff09\u3001\u4e2d\u6b62\uff08abort\uff09\u3001\u9519\u8bef\u5904\u7406\uff08error handling\uff09\u3001\u91cd\u8bd5\uff08retry\uff0c\u4e5f\u4f1a\u5bfc\u81f4 CHECK_CONDITION \u5e76\u83b7\u53d6\u6709\u610f\u4e49\u7684 sense \u4fe1\u606f\uff09\u3002 \u6700\u540e\u4e00\u90e8\u5206\u4ee5\u793a\u4f8b scsi_cmnd \u8ddf\u8e2a\u5728\u5176\u751f\u547d\u5468\u671f\u4e2d\u6240\u53ef\u80fd\u51fa\u73b0\u7684\u8def\u5f84\uff08\u4e0d\u542b\u5e95\u5c42\u90e8\u5206\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u76ee\u5f55<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[1] scsi_cmnd \u7684\u751f\u547d\u5468\u671f<br \/>[2] scsi_cmnd \u5982\u4f55\u6392\u961f\u5230 LLD\uff08\u5e95\u5c42\u9a71\u52a8\u7a0b\u5e8f\uff09\u8fdb\u884c\u5904\u7406\uff1f<br \/>[3] \u4e00\u4e2a scsi_cmnd \u662f\u5982\u4f55\u5b8c\u6210\u7684\uff1f<br \/>[3.1] \u547d\u4ee4\u901a\u8fc7 scsi_softirq_done() \u5b8c\u6210<br \/>[3.2] \u547d\u4ee4\u901a\u8fc7 scsi_times_out()$ \u5b8c\u6210<br \/>[4] SCSI \u9519\u8bef\u5904\u7406<br \/>[4.1] \u6211\u4eec\u662f\u600e\u4e48\u6765\u5230\u8fd9\u91cc\u7684\uff1f<br \/>[4.2] \u9519\u8bef\u5904\u7406\u4ec0\u4e48\u65f6\u5019\u5b9e\u9645\u8fd0\u884c\uff1f<br \/>[4.3] SCSI \u9519\u8bef\u5904\u7406\u7a0b\u5e8f\u7ebf\u7a0b<br \/>[5] SCSI \u547d\u4ee4\u53ef\u4ee5\u88ab\u201c\u52ab\u6301\uff08hijacked\uff09\u201d<br \/>[6] SCSI \u547d\u4ee4\u4e2d\u6b62<br \/>[6.1]\u4e2d\u95f4\u5c42\u4f55\u65f6\u4f1a\u5c1d\u8bd5\u4e2d\u6b62\u547d\u4ee4\uff1f<br \/>[6.2] SCSI \u547d\u4ee4\u4e2d\u6b62\u5982\u4f55\u5de5\u4f5c\uff1f<br \/>[6.3] \u4e2d\u6b62\u4e5f\u53ef\u80fd\u5931\u8d25<br \/>[7] SCSI \u547d\u4ee4\u91cd\u8bd5<br \/>[7.1] \u4e2d\u7ea7\u4f55\u65f6\u91cd\u8bd5\u547d\u4ee4\uff1f<br \/>[7.2] \u91cd\u8bd5\u8d44\u683c\u6807\u51c6<br \/>[8] \u793a\u4f8b\uff1a\u9075\u5faa scsi_cmnd\uff08\u5bfc\u81f4 CHECK_CONDITION\uff09<br \/>[8.1] \u793a\u4f8b scsi_cmnd \u6240\u7528\u8def\u5f84\u7684\u9ad8\u7ea7\u89c6\u56fe<br \/>[8.2] \u5b9e\u9645\u91c7\u53d6\u7684\u8def\u5f84<br \/>[9] \u53c2\u8003\u8d44\u6599<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>scsi_cmnd \u7684\u751f\u547d\u5468\u671f SCSI Mid level \u4e0e\u5757\u5c42\u7684\u63a5\u53e3\u5c31\u50cf\u4efb\u4f55\u5176\u4ed6\u5757\u9a71\u52a8\u7a0b\u5e8f\u4e00\u6837\u3002 \u5bf9\u4e8e SCSI\u4e2d\u95f4\u5c42\u6dfb\u52a0\u5230\u7cfb\u7edf\u4e2d\u7684\u6bcf\u4e2a\u5757\u8bbe\u5907\uff0c\u5b83\u6307\u793a\u4e86\u4e00\u5806\u51fd\u6570\u6765\u670d\u52a1\u4e8e\u76f8\u5e94\u7684\u8bf7\u6c42\u961f\u5217\u3002 \u4ee5\u4e0b\u51fd\u6570\u5728\u5176\u751f\u547d\u5468\u671f\u5185\u4e0e scsi_cmnd \u76f8\u5173\u3002\u8bf7\u6ce8\u610f\uff0c\u6839\u636e\u5b9e\u9645\u60c5\u51b5\uff0c\u5b83\u53ef\u80fd\u4e0d\u4f1a\u7ecf\u5386\u5176\u4e2d\u4e00\u4e9b\u9636\u6bb5\uff0c\u6216\u8005\u53ef\u80fd\u5fc5\u987b\u591a\u6b21\u7ecf\u5386\u67d0\u4e9b\u9636\u6bb5\u3002 scsi_prep_fn()<br \/>\u7531\u5757\u5c42\u8c03\u7528\u4ee5\u51c6\u5907\u8bf7\u6c42\u3002 \u8fd9\u4e2a\u51fd\u6570\u5b9e\u9645\u4e0a\u4e3a\u8bf7\u6c42\u5206\u914d\u4e00\u4e2a\u65b0\u7684 scsi_cmnd\uff08\u6765\u81ea scsi_host-&gt;cmd_pool\uff09\u5e76\u8bbe\u7f6e\u5b83\u3002 \u8fd9\u662f scsi_smnd \u201c\u8bde\u751f\u201d\u7684\u5730\u65b9\u3002<br \/>\u8bf7\u6ce8\u610f\uff0c\u53ea\u6709\u5f53 blk req \u8fd8\u6ca1\u6709\u4e0e\u4e4b\u5173\u8054\u65f6\uff08req-&gt;special != NULL\uff09\uff0c\u624d\u4f1a\u5206\u914d\u4e00\u4e2a\u65b0\u7684 scsi_cmnd\u3002 \u5982\u679c SCSI \u8f83\u65e9\u5c1d\u8bd5\u8fc7\u8be5\u8bf7\u6c42\uff0c\u5219\u8be5\u8bf7\u6c42\u53ef\u80fd\u5df2\u7ecf\u5177\u6709 scsi_cmnd\uff0c\u5e76\u4e14\u5b83\u5bfc\u81f4\u51b3\u5b9a\u7a0d\u540e\u91cd\u8bd5\uff08\u56e0\u6b64\u8bf7\u6c42\u88ab\u653e\u56de\u961f\u5217\u4e2d\uff09\u3002 scsi_request_fn()<br \/>\u662f\u4e3a\u8bf7\u6c42\u961f\u5217\u63d0\u4f9b\u670d\u52a1\u7684\u5b9e\u9645\u529f\u80fd\u51fd\u6570\u3002 \u5b83\u7b80\u5355\u5730\u68c0\u67e5\u4e3b\u673a\u662f\u5426\u51c6\u5907\u597d\u63a5\u53d7\u65b0\u547d\u4ee4\uff0c\u5982\u679c\u662f\uff0c\u5b83\u4f1a\u5c06\u5176\u63d0\u4ea4\u7ed9 LLD\uff1a<br \/>scsi_request_fn()<br \/>-&gt;scsi_dispatch_cmd()<br \/>-&gt;hostt-&gt;queue_command() \u5982\u679c scsi_cmnd \u7531\u4e8e\u67d0\u79cd\u539f\u56e0\u65e0\u6cd5\u6392\u961f\u5230 LLD\uff0c\u8bf7\u6c42\u5c06\u653e\u56de\u539f\u59cb\u8bf7\u6c42\u961f\u5217\uff08\u7b49\u5f85\u7a0d\u540e\u91cd\u8bd5\uff09\u3002 scsi_softirq_done()<br \/>\u662f\u5728 LLD \u53cd\u9988\u547d\u4ee4\u5b8c\u6210\u540e\u8c03\u7528\u7684\u5904\u7406\u7a0b\u5e8f\u3002<br \/>scsi_done()<br \/>-&gt;blk_complete_request()<br \/>-&gt;\u5bfc\u81f4\u8f6f\u4e2d\u65ad<br \/>-&gt;blk_done_softirq()<br \/>-&gt;scsi_softirq_done() \u6b64\u51fd\u6570\u6700\u91cd\u8981\u7684\u76ee\u6807\u662f\u786e\u5b9a\u6b64\u8bf7\u6c42\u7684\u8fdb\u4e00\u6b65\u64cd\u4f5c\u8fc7\u7a0b\uff08\u57fa\u4e8e scsi_cmnd-&gt;result \u548c\u611f\u77e5\u6570\u636e\uff08\u5982\u679c\u5b58\u5728\uff09\uff09\uff0c\u5e76\u6267\u884c\u8be5\u8fc7\u7a0b\u3002 \u76f8\u5e94\u7684\u9009\u9879\u53ef\u4ee5\u662f\u5b8c\u6210\u5bf9\u5757\u5c42\u7684\u8bf7\u6c42\u3001\u5c06\u5176\u91cd\u65b0\u6392\u961f\u5230\u5757\u5c42\u3001\u6216\u5b89\u6392\u5b83\u8fdb\u884c\u9519\u8bef\u5904\u7406\uff08\u5982\u679c\u8ba4\u4e3a\u6709\u5fc5\u8981\uff09\u3002 \u7a0d\u540e\u5c06\u5bf9\u6b64\u8fdb\u884c\u66f4\u8be6\u7ec6\u7684\u8ba8\u8bba\u3002 scsi_times_out()<br \/>\u662f\u5728 LLD \u957f\u65f6\u95f4\u672a\u54cd\u5e94 scsi_cmnd \u7684\u7ed3\u679c\u5e76\u4e14\u53d1\u751f\u8d85\u65f6\u65f6\u8c03\u7528\u7684\u51fd\u6570\u3002 \u5b83\u4f1a\u5c1d\u8bd5\u67e5\u770b\u662f\u5426\u53ef\u4ee5\u901a\u8fc7 LLD \u8d85\u65f6\u5904\u7406\u7a0b\u5e8f\uff08\u5982\u679c\u53ef\u7528\uff09\u6216\u4e2d\u6b62\u547d\u4ee4\u6765\u4fee\u590d\u8fd9\u79cd\u60c5\u51b5\u3002 \u5982\u679c\u4e0d\u662f\uff0c\u5b83\u4f1a\u4e3a EH \u5b89\u6392\u547d\u4ee4\uff08\u7a0d\u540e\u8be6\u7ec6\u8ba8\u8bba\uff09\u3002 scsi_unprep_fn()<br \/>\u662f\u88ab\u8c03\u7528\u4ee5\u53d6\u6d88\u51c6\u5907\u8bf7\u6c42\u7684\u51fd\u6570\u3002 \u5b83\u5e94\u8be5\u64a4\u6d88 scsi_prep_fn() \u6240\u505a\u7684\u4efb\u4f55\u4e8b\u60c5\u3002<\/li>\n\n\n\n<li>scsi_cmnd \u5982\u4f55\u6392\u961f\u5230 LLD \u8fdb\u884c\u5904\u7406\uff1f \u63d0\u4ea4\u90e8\u5206\u975e\u5e38\u7b80\u5355\u3002 \u4e00\u65e6\u4e3a\u5757\u8bf7\u6c42\u8c03\u7528 scsi_request_fn() \u5e76\u901a\u8fc7 blk_peek_request() \u83b7\u53d6\u65b0\u7684\u5757\u8bf7\u6c42\uff0cscsi_cmnd \u5df2\u7ecf\u8bbe\u7f6e\u5e76\u51c6\u5907\u597d\u53d1\u9001\u5230 LLD\uff1a<br \/>scsi_request_fn()<br \/>-&gt;scsi_dispatch_cmd()<br \/>-&gt;hostt-&gt;queue_command()<\/li>\n\n\n\n<li>scsi_cmnd \u662f\u5982\u4f55\u5b8c\u6210\u7684\uff1f \u5c06 scsi_cmnd \u63d0\u4ea4\u7ed9 LLD \u540e\uff0c\u53ea\u6709\u4e24\u79cd\u65b9\u6cd5\u53ef\u4ee5\u5b8c\u6210\u5b83\uff1a A\u3002 \u8981\u4e48 LLD \u53ca\u65f6\u54cd\u5e94\u3002<br \/>\uff08\u5373 \u7ed3\u679c\u4e3a\u901a\u8fc7 scsi_softirq_done() \u7ee7\u7eed\u5904\u7406\u547d\u4ee4\uff09 b. \u6216\u8005\uff0cLLD\u6ca1\u6709\u53ca\u65f6\u54cd\u5e94\uff0c\u53d1\u751f\u8d85\u65f6<br \/>\uff08\u5373 \u7ed3\u679c\u4e3a\u901a\u8fc7 scsi_times_out() \u7ee7\u7eed\u5904\u7406\u547d\u4ee4\uff09 \u6211\u4eec\u5728\u4e0b\u9762\u8ba8\u8bba\u8fd9\u4e24\u79cd\u60c5\u51b5\u3002 \u6ce8 1\uff1a<br \/>\u53ef\u80fd\u6709\u91cd\u8bd5\u7684 scsi_cmnd(s)\u3002 \u4f46\u662f\u91cd\u8bd5\u7684 scsi_cmnd \u7684\u5b8c\u6210\u4e0e\u65b0 scsi_cmnd \u7684\u5b8c\u6210\u6ca1\u6709\u4efb\u4f55\u4e0d\u540c\u3002 \u56e0\u6b64\uff0c\u65e0\u8bba\u91cd\u8bd5\u7684\u7ed3\u679c\u5982\u4f55\uff0cscsi_cmnds \u5c06\u59cb\u7ec8\u4f7f\u7528\u4e0a\u8ff0\u4e24\u79cd\u60c5\u51b5\u4e4b\u4e00\u7ed3\u675f\u3002 \u6ce8 2\uff1a<br \/>\u5728 scsi_send_eh_cmnd() \u7684\u9519\u8bef\u5904\u7406\u671f\u95f4\uff0cscsi_cmnd \u53ef\u80fd\u88ab\u201c\u52ab\u6301\u201d\uff0c\u4ee5\u53d1\u9001 EH \u547d\u4ee4\u4e4b\u4e00 (TUR \/ STU \/ REQUEST_SENSE)\u3002 \u4f46\u662f\uff0c\u8fd9\u4e9bEH\u547d\u4ee4\u7684\u5b8c\u6210\u5e76\u6ca1\u6709\u5728\u4ee5\u4e0a\u4e24\u79cd\u573a\u666f\u4e2d\u843d\u5730\u3002 \u8fd9\u662f\u552f\u4e00\u7684\u4f8b\u5916\u3002 \u4e00\u65e6 scsi_cmnd \u88ab\u201c\u89e3\u9664\u52ab\u6301\u201d\uff0c\u8fd9\u4e2a\u539f\u59cb scsi_cmnd \u7684\u7ed3\u679c\u4ecd\u5c06\u7ecf\u5386\u76f8\u540c\u7684 2 \u4e2a\u573a\u666f\u4e4b\u4e00\u3002 3.1 \u547d\u4ee4\u901a\u8fc7 scsi_softirq_done() \u5b8c\u6210 \u5f53 LLD \u53ca\u65f6\u54cd\u5e94\u65f6\u5c31\u662f\u8fd9\u79cd\u60c5\u51b5\uff0c\u4f8b\u5982\u547d\u4ee4\u6b63\u5e38\u5b8c\u6210\u3002<br \/>\u8bf7\u6ce8\u610f\uff0c\u8fd9\u91cc\u7684\u201c\u5b8c\u6210\u201d\u5e76\u4e0d\u610f\u5473\u7740\u547d\u4ee4\u5df2\u6210\u529f\u5b8c\u6210\u3002\u4e8b\u5b9e\u4e0a\uff0cSCSI \u4e3b\u673a\u786c\u4ef6\u751a\u81f3\u53ef\u80fd\u5728\u6ca1\u6709\u63a5\u53d7\u547d\u4ee4\u7684\u60c5\u51b5\u4e0b\u53d1\u751f\u6545\u969c\u3002\u7136\u800c\uff0cscsi_softirq_done() \u88ab\u8c03\u7528\u7684\u4e8b\u5b9e\u8868\u660e\u6709\u53ca\u65f6\u53ef\u7528\u7684\u201c\u7ed3\u679c\u201d\u3002\u6211\u4eec\u5fc5\u987b\u68c0\u67e5\u8fd9\u4e2a\u7ed3\u679c\u624d\u80fd\u51b3\u5b9a\u4e0b\u4e00\u6b65\u884c\u52a8\u3002 scsi_softirq_done()<br \/>|<br \/>+&#8212;&gt; scsi_decide_disposition()<br \/>| \u67e5\u770b scsi_cmnd-&gt;result \u548c\u611f\u77e5\uff08sense\uff09\u6570\u636e\u4ee5\u786e\u5b9a\u91c7\u53d6\u7684\u6700\u4f73\u884c\u52a8\u65b9\u6848\u3002\u5728\u9605\u8bfb\u6b64\u51fd\u6570\u4ee3\u7801\u65f6\uff0c\u4e0d\u5e94\u5c06 SUCCESS \u6df7\u6dc6\u4e3a\u8868\u793a\u547d\u4ee4\u6210\u529f\uff0c\u6216\u5c06 FAILED \u6df7\u6dc6\u4e3a\u8868\u793a\u547d\u4ee4\u5931\u8d25\u7b49\u3002\u6b64\u51fd\u6570\u7684\u8fd4\u56de\u503c\u4ec5\u6307\u793a\u8981\u91c7\u53d6\u7684\u64cd\u4f5c\u8fc7\u7a0b<br \/>|<br \/>+&#8212;&gt; \u7ed3\u679c\u4e3a SUCCESS \u65f6\uff1a<br \/>| \uff08\u5b8c\u6210\u5230\u5757\u5c42\u7684\u547d\u4ee4\u3002\u4f8b\u5982\uff0c\u8bbe\u5907\u53ef\u80fd\u5904\u4e8e\u79bb\u7ebf\u72b6\u6001\uff0c\u56e0\u6b64\u5b8c\u6210\u547d\u4ee4 &#8211; \u5757\u5c42\u53ef\u80fd\u7a0d\u540e\u81ea\u884c\u91cd\u8bd5\uff0c\u4f46\u8fd9\u4e0e SCSI ML \u65e0\u5173\uff09<br \/>| |<br \/>| +&#8212;&gt; scsi_finish_command()<br \/>| |<br \/>| +&#8212;&gt; scsi_io_completion()\uff08*\u89c1\u4e0b\u9762\u7684\u6ce8\u91ca\uff09<br \/>| |<br \/>| +&#8212;&gt; blk_finish_request()<br \/>|<br \/>+&#8212;&gt; \u7ed3\u679c\u4e3a RETRY\/ADD_TO_MLQUEUE \u65f6\uff1a<br \/>| \uff08\u91cd\u65b0\u6392\u961f\u8bf7\u6c42\u961f\u5217\u7684\u547d\u4ee4\u3002\u4f8b\u5982\uff0c\u8bbe\u5907\u786c\u4ef6\u662f\u5fd9\u7684\uff0c\u56e0\u6b64 SCSI ML \u77e5\u9053\u91cd\u8bd5\u53ef\u80fd\u4f1a\u6709\u5e2e\u52a9\uff09<br \/>|<br \/>| |<br \/>| +&#8212;&gt; scsi_queue_insert()<br \/>| |<br \/>| +&#8212;&gt; blk_requeue_request()<br \/>|<br \/>+&#8212;&gt; \u7ed3\u679c\u4e3a FAILED\/default \u65f6\uff1a<br \/>\uff08 \u5b89\u6392 scsi_cmnd \u8fdb\u5165 EH \u3002\u4f8b\u5982\uff0c\u5b58\u5728\u53ef\u80fd\u9700\u8981\u603b\u7ebf\u91cd\u7f6e\u7684\u603b\u7ebf\u9519\u8bef\u3002\u6216\u8005\u6211\u4eec\u5f97\u5230 CHECK_CONDITION\uff0c\u6211\u4eec\u9700\u8981\u53d1\u51fa REQ_SENSE \u4ee5\u83b7\u53d6\u6709\u5173\u6545\u969c\u7684\u66f4\u591a\u4fe1\u606f\u7b49\uff09<br \/>|<br \/>+&#8212;&gt; scsi_eh_scmd_add()<br \/>\u5c06 scsi_cmnd \u6dfb\u52a0\u5230\u4e3b\u673a EH \u961f\u5217<br \/>scsi_eh_wakeup() \u6ce83\uff1a<br \/>scsi_io_completion() \u6709\u4e00\u4e2a\u7c7b\u4f3c\u4e8e scsi_decide_disposition() \u7684\u8f85\u52a9\u903b\u8f91\uff0c\u56e0\u4e3a\u5b83\u4e5f\u67e5\u770b\u7ed3\u679c\u548c\u611f\u77e5\u6570\u636e\u5e76\u786e\u5b9a\u5982\u4f55\u5904\u7406\u8bf7\u6c42\u3002\u5b83\u5728\u8981\u91c7\u53d6\u7684\u884c\u52a8\u8fc7\u7a0b\u4e2d\u505a\u51fa\u7c7b\u4f3c\u7684\u9009\u62e9\u3002 \u6b64\u51fd\u6570\u4e2d\u6709\u4e00\u4e2a\u7279\u6b8a\u60c5\u51b5\u6d89\u53ca\u5728\u91cd\u65b0\u6392\u961f\u4e4b\u524d\u201c\u53d6\u6d88\u51c6\u5907\uff08unprepping\uff09\u201dscsi_cmnd\uff0c\u6211\u4eec\u5c06\u5728\u4e0b\u9762\u7684\u90e8\u5206\u4e2d\u8ba8\u8bba\u5b83\u3002 3.2 \u547d\u4ee4\u901a\u8fc7 scsi_times_out() \u5b8c\u6210 \u5f53 LLD \u6ca1\u6709\u53ca\u65f6\u54cd\u5e94\u3001\u5757\u5c42\u8d85\u65f6\uff0c\u5e76\u56e0\u6b64\u8c03\u7528\u76f8\u5173 SCSI \u8bbe\u5907\u7684\u8bf7\u6c42\u961f\u5217\u7684\u8d85\u65f6\u51fd\u6570\u65f6\uff0c\u5c31\u4f1a\u53d1\u751f\u8fd9\u79cd\u60c5\u51b5\u3002 scsi_times_out()<br \/>|<br \/>+&#8212;&gt; scsi_transport_template-&gt;eh_timed_out() &#8211; \u6210\u529f\u4e86\u5417\uff1f \u5982\u679c\u4e0d\u2026<br \/>| \uff08\u7ed9transportt\u4e00\u4e2a\u5904\u7406\u7684\u673a\u4f1a\uff09<br \/>|<br \/>+&#8212;&gt; scsi_host_template-&gt;eh_timed_out() &#8211; \u6210\u529f\u4e86\u5417\uff1f \u5982\u679c\u4e0d\u2026<br \/>| \uff08\u7ed9hostt\u4e00\u4e2a\u5904\u7406\u7684\u673a\u4f1a\uff09<br \/>|<br \/>+&#8212;&gt; scsi_abort_command() &#8211; \u6210\u529f\u4e86\u5417\uff1f \u5982\u679c\u4e0d\u2026<br \/>| \uff08\u5b89\u6392 scsi_cmnd \u7684 ABORT\u3002\u5982\u679c\u9700\u8981\uff0c\u4e2d\u6b62\u5904\u7406\u7a0b\u5e8f\u8fd8\u5c06\u91cd\u65b0\u6392\u961f\uff09<br \/>|<br \/>+&#8212;&gt; scsi_eh_scmd_add()<br \/>\uff08\u4e3a EH \u5b89\u6392 scsi_cmnd\u3002\u8fd9\u80af\u5b9a\u6709\u6548\u3002\u56e0\u4e3a\u5982\u679c\u5b83\u4e0d\u8d77\u4f5c\u7528\uff0cEH \u5904\u7406\u7a0b\u5e8f\u4f1a\u5c06\u8bbe\u5907\u6807\u8bb0\u4e3a\u79bb\u7ebf\uff0c\u8fd9\u7b97\u662f\u4e00\u4e2a\u5f88\u597d\u7684\u4fee\u590d:-)\uff09<\/li>\n\n\n\n<li>SCSI \u9519\u8bef\u5904\u7406 SCSI \u9519\u8bef\u5904\u7406\u5e94\u8be5\u88ab\u8ba4\u4e3a\u662f ML \u5728\u77e5\u9053\u4ec5\u4ec5\u91cd\u8bd5\u8bf7\u6c42\u53ef\u80fd\u65e0\u6d4e\u4e8e\u4e8b\u5e76\u4e14\u9700\u8981\u505a\u5176\u4ed6\u4e8b\u60c5\uff08\u53ef\u80fd\u662f\u7834\u574f\u6027\u7684\uff09\u6765\u89e3\u51b3\u95ee\u9898\u65f6\u51b3\u5b9a\u91c7\u53d6\u7684\u884c\u52a8\u3002 \u4f8b\u5982 \u505c\u6ede\u7684\uff08stalled\uff09\u4e3b\u673a\u53ef\u80fd\u9700\u8981\u4e3b\u673a\u91cd\u7f6e\uff0c\u5e76\u4e14\u53ea\u6709\u5728\u6b64\u4e4b\u540e\u624d\u80fd\u5b8c\u6210\u8bf7\u6c42\u7684\u91cd\u8bd5\u3002 \u6ce84\uff1a<br \/>\uff08\u968f\u673a\u60f3\u6cd5\uff09\uff1a\u5c06\u201c\u9519\u8bef\u5904\u7406\uff08Error Handling\uff09\u201d\u4e0e\u201c\u91cd\u8bd5\uff08Retries\uff09\u201d\u8fdb\u884c\u5bf9\u6bd4\u3002\u91cd\u8bd5\u662f\u4e00\u4ef6\u6b63\u5e38\u7684\u4e8b\u60c5\uff0c\u5f53\u4e2d\u5c42\u8ba4\u4e3a\u5b83\u770b\u5230\u4e86\u4e00\u4e2a\u672c\u8d28\u4e0a\u662f\u6682\u65f6\u7684\u9519\u8bef\uff0c\u5e76\u4e14\u4f1a\u81ea\u884c\u6d88\u5931\u800c\u65e0\u9700\u660e\u786e\u5730\u505a\u4efb\u4f55\u4e8b\u60c5\u3002\u56e0\u6b64\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u518d\u6b21\u91cd\u8bd5\u8bf7\u6c42\u662f\u6709\u610f\u4e49\u7684\u3002\uff08\u53e6\u4e00\u65b9\u9762\uff0c\u4e00\u4e2a cmnd \u88ab\u5b89\u6392\u7528\u4e8e EH\uff0c\u5f53\u5b83\u77e5\u9053\u5b83\u9700\u8981\u5728\u91cd\u8bd5 cmnd \u53ef\u4ee5\u7ed9\u51fa\u597d\u7684\u7ed3\u679c\u4e4b\u524d\u505a\u201c\u67d0\u4e8b\u201d\u65f6\uff09\u3002 \u6ce85\uff1a<br \/>SCSI \u4e2d\u95f4\u5c42\u4f7f\u7528 scsi_host-&gt;eh_cmd_q \u7ef4\u62a4\u4e00\u4e2a\uff08\u6bcf\u4e2a\u4e3b\u673a\uff09\u5217\u8868\uff0c\u5176\u4e2d\u5305\u542b\u5df2\u5728\u8be5\u4e3b\u673a\u4e0a\u4e3a EH \u5b89\u6392\u7684\u6240\u6709 scsi_cmnd\u3002<br \/>\u8fd9\u662f EH \u7ebf\u7a0b\u5728\u8fd0\u884c\u65f6\u5904\u7406\u7684\u5217\u8868\u3002 4.1 \u6211\u4eec\u662f\u5982\u4f55\u5230\u8fbe\u8fd9\u91cc\u7684\uff1f<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4ee5\u4e0b\u60c5\u51b5\u4e0b\uff0c\u53ef\u4ee5\u5c06 scsi_cmnd \u6807\u8bb0\u4e3a EH\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u547d\u4ee4\u201c\u9519\u8bef\u5b8c\u6210\uff08error completed\uff09\u201d\uff0c\u5373 scsi_decide_disposition() \u8fd4\u56de FAILED \u6216\u8868\u793a\u9700\u8981\u67d0\u79cd\u9519\u8bef\u6062\u590d\u7684\u5931\u8d25\u7684\u4e1c\u897f\u3002 \u4f8b\u5982 \u8bbe\u5907\u786c\u4ef6\u51fa\u73b0\u6545\u969c\uff0c\u6216\u8005\u6211\u4eec\u6709 CHECK_CONDITION\u3002<br \/>scsi_softirq_done()<br \/>-&gt;scsi_decide_disposition = FAILED<br \/>-&gt;scsi_eh_scmd_add()<\/li>\n\n\n\n<li>scsi_cmnd \u8d85\u65f6\uff0c\u5c1d\u8bd5\u4e2d\u6b62\u5931\u8d25\u3002<br \/>scsi_times_out()<br \/>-&gt;scsi_abort_command() != SUCCESS<br \/>-&gt;scsi_eh_scmd_add() 4.2 \u9519\u8bef\u5904\u7406\u4ec0\u4e48\u65f6\u5019\u771f\u6b63\u8fd0\u884c\uff1f<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ea\u8981\u6709\u6807\u8bb0\u4e3a EH \u7684 scsi_smnd\uff08\u63d2\u5165\u5230 Scsi_Host-&gt;eh_cmd_q \u4e2d\uff09\uff0c\u5c31\u4f1a\u8c03\u5ea6 SCSI \u9519\u8bef\u5904\u7406\u7a0b\u5e8f\u7ebf\u7a0b\u3002\u4e00\u65e6 scsi_cmnd \u88ab\u6807\u8bb0\u4e3a EH\uff0cML \u5c31\u4e0d\u518d\u63a5\u53d7\u8be5\u7279\u5b9a Scsi_Host \u7684\u4efb\u4f55 scsi_cmnd\u3002\u7136\u800c\uff0cEH \u7ebf\u7a0b\u5b9e\u9645\u4e0a\u5e76\u6ca1\u6709\u8fd0\u884c\uff0c\u76f4\u5230\u8be5\u7279\u5b9a Scsi_Host \u7684\u6240\u6709\u672a\u51b3 IO \u5230 LLD \u5df2\u5b8c\u6210\u6216\u5931\u8d25\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u5728\u8be5\u4e3b\u673a\u7684 LLD \u4e0a\u6302\u8d77\u7684\u552f\u4e00\u547d\u4ee4\u662f\u9700\u8981 EH (host_busy == host_failed) \u7684\u547d\u4ee4\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u60f3\u6cd5\u662f\u505c\u6b62\u603b\u7ebf\uff08quiesce the bus\uff09\uff0c\u4ee5\u4fbf EH \u7ebf\u7a0b\u53ef\u4ee5\u6062\u590d\u8bbe\u5907\uff0c\u56e0\u4e3a\u5b83\u53ef\u80fd\u9700\u8981\u91cd\u7f6e\u4e0d\u540c\u7684\u7ec4\u4ef6\u624d\u80fd\u5b8c\u6210\u5176\u5de5\u4f5c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8865\u6ce8 1:<br \/>\u8fd9\u91cc\u7684\u7ec4\u4ef6\u5373 HBTL \u56db\u4e2a\u5c42\u7ea7\u3002Host:Bus:Target:LUN \u5bf9\u5e94\u7684 \u4e3b\u673a\uff1a\u603b\u7ebf\uff1a\u76ee\u6807\u7aef\uff1a\u76d8 \u56db\u8005\u5012\u5e8f\u5206\u522b\u6267\u884c\u3002<br \/>\u5728\u5b9e\u9645\u6267\u884c\u91cd\u7f6e\u65f6\uff0c\u5b9e\u9645\u6267\u884c\u7684\u64cd\u4f5c\u9664\u4e0e\u5b9e\u9645\u95ee\u9898\u76f8\u5173\u5916\uff0c\u8fd8\u4e0e\u76f8\u5e94\u7684\u5e95\u5c42\u8bbe\u5907\u9a71\u52a8\uff08LLD\uff09\u8bbe\u8ba1\u76f8\u5173\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">4.3 SCSI \u9519\u8bef\u5904\u7406\u5668\u7ebf\u7a0b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_error_handler()<br \/>|<br \/>+&#8212;&gt; transportt-&gt;eh_strategy_handler() \u5982\u679c\u5b58\u5728\uff0c\u5426\u5219\u2026<br \/>| \uff08\u5982\u679c\u53ef\u7528\uff0c\u4f7f\u7528 transportt \u81ea\u5df1\u7684\u9519\u8bef\u6062\u590d\u5904\u7406\u7a0b\u5e8f\uff09<br \/>|<br \/>+&#8212;&gt; scsi_unjam_host()<br \/>| \uff08\u4e0b\u9762\u63cf\u8ff0\u7684 SCSI ML \u9519\u8bef\u5904\u7406\u7a0b\u5e8f\u3002\u4e5f\u5728 Documentation\/scsi\/scsi_eh.txt \u4e2d\u63cf\u8ff0\u3002\u57fa\u672c\u76ee\u6807\u662f\u6267\u884c\u4efb\u4f55\u9700\u8981\u4ece\u5f53\u524d\u9519\u8bef\u6761\u4ef6\u4e2d\u6062\u590d\u7684\u64cd\u4f5c\u3002\u5e76\u5728\u6062\u590d\u540e\u91cd\u65b0\u6392\u961f\u7b26\u5408\u6761\u4ef6\u7684\u547d\u4ee4\uff09<br \/>|<br \/>+&#8212;&gt; scsi_restart_operations()<br \/>(\u91cd\u542fSCSI\u8bf7\u6c42\u961f\u5217\u7684\u64cd\u4f5c)<br \/>|<br \/>+&#8212;&gt; scsi_run_host_queues()<br \/>|<br \/>+&#8212;&gt; scsi_run_queue()<br \/>|<br \/>+&#8212;&gt; blk_run_queue()<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_unjam_host()<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u60f3\u6cd5\u662f\u521b\u5efa 2 \u4e2a\u5217\u8868\uff1awork_q\u3001done_q\u3002<br \/>\u6700\u521d\uff0cwork_q = , done_q = NULL\u3002\u7136\u540e\u4f9d\u6b21\u9012\u589e\u91c7\u53d6\u53ef\u80fd\u6062\u590d cmnd \u6216\u8bbe\u5907\u7684\u66f4\u9ad8\u4e25\u91cd\u6027\u7684\u64cd\u4f5c\u9879\uff0c\u5bf9 work_q \u4e2d\u7684\u6240\u6709\u8bf7\u6c42\u8fdb\u884c\u9519\u8bef\u5904\u7406\u3002\u4e0d\u65ad\u5c06\u8bf7\u6c42\u4ece work_q \u79fb\u52a8\u5230 done_q\uff0c\u6700\u540e\u4e00\u6b21\u5b8c\u6210\u6240\u6709\u8bf7\u6c42\uff0c\u800c\u4e0d\u662f\u5355\u72ec\u5b8c\u6210\u5b83\u4eec\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_unjam_host()<br \/>|<br \/>+&#8211;&gt; \u521b\u5efa 2 \u4e2a\u5217\u8868\uff1awork_q\u3001done_q<br \/>| work_q = &lt;\u6240\u6709 EH scsi \u547d\u4ee4&gt;\uff0cdone_q = NULL<br \/>|<br \/>+&#8211;&gt; scsi_eh_get_sense() &#8211; \u6211\u4eec\u5b8c\u6210\u4e86\u5417\uff1f \u5982\u679c\u4e0d\u2026<br \/>| \uff08\u5bf9\u4e8e\u6709CHECK_CONDITION\u7684\u547d\u4ee4\uff0c\u83b7\u53d6 sense_info\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_request_sense()<br \/>| | \uff08\u4f7f\u7528 scsi_send_eh_cmnd() \u53d1\u9001\u201c\u88ab\u52ab\u6301\u7684\uff08hijacked\uff09\u201dREQ_SENSE \u547d\u4ee4\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_decide_disposition()<br \/>| |<br \/>| +&#8211;&gt; \u5982\u679c\u6210\u529f\uff08SUCCESS\uff09\u5219\u5b89\u6392\u5b8c\u6210 scsi_cmnd\uff08\u901a\u8fc7\u8bbe\u7f6e retries=allowed\uff09<br \/>|<br \/>+&#8211;&gt; scsi_eh_abort_cmds() &#8211; \u6211\u4eec\u5b8c\u6210\u4e86\u5417\uff1f \u5982\u679c\u4e0d\u2026<br \/>| \uff08\u4e2d\u6b62\u8d85\u65f6\u7684\u547d\u4ee4\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_try_to_abort_cmd()<br \/>| | \uff08\u5bfc\u81f4\u8c03\u7528 hostt-&gt;eh_abort_handler()\uff0c\u5b83\u8d1f\u8d23\u4f7f LLD \u548c HW \u5fd8\u8bb0 scsi_cmnd\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_eh_test_devices()<br \/>| \uff08\u901a\u8fc7\u53d1\u9001\u9002\u5f53\u7684 EH \u547d\u4ee4 (STU \/ TEST_UNIT_READY) \u6d4b\u8bd5\u8bbe\u5907\u73b0\u5728\u662f\u5426\u54cd\u5e94\u3002\u540c\u6837\uff0c\u53d1\u9001\u8fd9\u4e9b EH \u547d\u4ee4\u6d89\u53ca\u52ab\u6301\u539f\u59cb scsi_cmnd\uff0c\u7136\u540e\u6062\u590d\u4e0a\u4e0b\u6587\uff09<br \/>|<br \/>+&#8211;&gt; scsi_eh_ready_devs() &#8211; \u6211\u4eec\u5b8c\u6210\u4e86\u5417\uff1f \u5982\u679c\u4e0d\u2026<br \/>| \uff08\u91c7\u53d6\u9012\u589e\u7684\u987a\u5e8f\u8fdb\u884c\u66f4\u9ad8\u4e25\u91cd\u6027\u7684\u64cd\u4f5c\u4ee5\u6062\u590d\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_eh_bus_device_reset()<br \/>| | \uff08\u91cd\u7f6e scsi_device\u3002\u5bfc\u81f4\u8c03\u7528 hostt-&gt;eh_device_reset_handler()\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_eh_target_reset()<br \/>| | \uff08\u91cd\u7f6e scsi_target\u3002\u5bfc\u81f4\u8c03\u7528 hostt-&gt;eh_target_reset_handler()\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_eh_bus_reset()<br \/>| | \uff08\u91cd\u7f6e scsi_bus\u3002\u5bfc\u81f4\u8c03\u7528 hostt-&gt;eh_bus_reset_handler()\uff09<br \/>| |<br \/>| +&#8211;&gt; scsi_eh_host_reset()<br \/>| | \uff08\u91cd\u7f6e Scsi_Host\u3002\u5bfc\u81f4\u8c03\u7528 hostt-&gt;eh_host_reset_handler()\uff09<br \/>| |<br \/>| +&#8211;&gt; \u5982\u679c\u6ca1\u6709\u4efb\u4f55\u6548\u679c &#8211; scsi_eh_offline_sdevs()<br \/>| \uff08\u8bbe\u5907\u4e0d\u53ef\u6062\u590d\uff0c\u8bf7\u4e0b\u7ebf\uff09<br \/>|<br \/>+&#8211;&gt; scsi_eh_flush_done_q()<br \/>\uff08\u5bf9\u4e8e done_q \u4e0a\u7684\u6240\u6709 EH \u547d\u4ee4\uff0c\u5982\u679c\u7b26\u5408\u6761\u4ef6\uff0c\u8981\u4e48\u5c06\u5b83\u4eec\u91cd\u65b0\u6392\u961f\uff08\u901a\u8fc7 scsi_queue_insert()\uff09\uff0c\u8981\u4e48\u5c06\u5b83\u4eec\u5b8c\u6210\u5230\u5757\u5c42\uff08\u901a\u8fc7 scsi_finish_command()\uff09<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ce8 6\uff1a<br \/>\u5728\u6bcf\u4e2a\u6062\u590d\u9636\u6bb5\uff0c\u6211\u4eec\u5747\u9700\u8981\u6d4b\u8bd5\u662f\u5426\u5df2\u5b8c\u6210\u672c\u9636\u6bb5\u7684\u9519\u8bef\u6062\u590d\uff08\u4f7f\u7528 scsi_eh_test_devices()\uff09\uff0c\u5e76\u4ec5\u5728\u9700\u8981\u65f6\u624d\u91c7\u53d6\u4e0b\u4e00\u4e2a\u66f4\u9ad8\u4e25\u91cd\u6027\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ce8 7\uff1a<br \/>\u9519\u8bef\u5904\u7406\u7a0b\u5e8f\u4f1a\u68c0\u67e5\u662f\u5426\u53ef\u4ee5\u901a\u8fc7\u91cd\u7f6e\u67d0\u4e00\u76f8\u540c\u7ec4\u4ef6\uff08\u4f8b\u5982\uff0c\u76f8\u540c\u7684 scsi_device\uff09\u6765\u6062\u590d\u7684\u591a\u4e2a scsi_cmnd\uff0c\u5982\u679c\u53ef\u4ee5\u5219\u6b64\u7ec4\u4ef6\u53ea\u4f1a\u91cd\u7f6e\u4e00\u6b21\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\" start=\"5\">\n<li>SCSI\u547d\u4ee4\u53ef\u4ee5\u88ab\u201c\u52ab\u6301\uff08hijacked\uff09\u201d \u5982\u4e0a\u6240\u793a\uff0cEH \u7ebf\u7a0b\u53ef\u80fd\u9700\u8981\u53d1\u9001\u4e00\u4e9b EH \u547d\u4ee4\u624d\u80fd\u68c0\u67e5 SCSI \u8bbe\u5907\u7684\u5065\u5eb7\u72b6\u51b5\u548c\u54cd\u5e94\u80fd\u529b\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>TUR &#8211; Test Unit Ready\uff0c\u6d4b\u8bd5\u5355\u5143\u5c31\u7eea<\/li>\n\n\n\n<li>STU &#8211; Start \/ Stop Unit\uff0c\u542f\u52a8\/\u505c\u6b62\u5355\u5143<\/li>\n\n\n\n<li>REQUEST_SENSE &#8211; \u83b7\u53d6\u54cd\u5e94 CHECK_CONDITION \u7684 Sense \u6570\u636e \u7136\u800c\uff0cEH \u7ebf\u7a0b\u5e76\u6ca1\u6709\u4e3a\u8fd9\u79cd\u4e34\u65f6\u76ee\u7684\u5206\u914d\u548c\u8bbe\u7f6e\u65b0\u7684 scsi_cmnd\uff0c\u800c\u662f\u52ab\u6301\u5b83\u8bd5\u56fe\u6062\u590d\u7684\u5f53\u524d scsi_cmnd\uff0c\u4ee5\u4fbf\u53d1\u9001 EH \u547d\u4ee4\u3002\u6574\u4e2a\u8fc7\u7a0b\u5728 scsi_send_eh_cmnd() \u4e2d\u5b8c\u6210\u3002 scsi_send_eh_cmnd \u5728\u52ab\u6301\u5b83\u4e4b\u524d\u4fdd\u5b58\u5f53\u524d\u547d\u4ee4\u7684\u4e0a\u4e0b\u6587\uff0c\u5728\u5c06\u5b83\u5206\u53d1\u5230 LLD \u4e4b\u524d\u7528\u5b83\u81ea\u5df1\u7684\u66ff\u6362 scsi_done ptr\uff0c\u5e76\u5728\u5b8c\u6210\u540e\u6062\u590d\u4e0a\u4e0b\u6587\u3002\u4ee5\u8fd9\u79cd\u65b9\u5f0f\u53d1\u9001\u7684 EH \u547d\u4ee4\u4f1a\u9047\u5230\u76f8\u540c\u7684\u8d85\u65f6\/\u4e2d\u6b62\u5931\u8d25\/\u5b8c\u6210 &#8211; \u4f46\u5b83\u4eec\u4e0d\u4f1a\u91c7\u7528\u666e\u901a\u547d\u4ee4\u6240\u91c7\u7528\u7684\u8def\u7531\uff08\u5373\u4e0d\u91c7\u7528 scsi_softirq_done() \u6216 scsi_times_out() \u8def\u7531\uff09\u3002\u6bcf\u4ef6\u4e8b\u90fd\u5728 scsi_send_eh_cmnd() \u4e2d\u5904\u7406\u3002 \u8fd9\u5c06\u5728\u4ee5\u4e0b\u5404\u8282\u4e2d\u8ba8\u8bba\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\" start=\"5\">\n<li>SCSI \u547d\u4ee4\u4e2d\u6b62 \u5b83\u6307\u7684\u662f SCSI\u4e2d\u95f4\u5c42\u60f3\u8981\u8ba9 \u5e95\u5c42\u9a71\u52a8\u7a0b\u5e8f\u548c\u5b83\u4e0b\u9762\u7684\u786c\u4ef6\u5fd8\u8bb0\u4e4b\u524d\u63d0\u4f9b\u7ed9 LLD \u7684 scsi_cmnd \u7684\u6240\u6709\u5185\u5bb9\u7684\u573a\u666f\u3002\u6700\u5e38\u89c1\u7684\u539f\u56e0\u662f LLD \u672a\u80fd\u53ca\u65f6\u54cd\u5e94\u3002 6.1 \u4e2d\u95f4\u5c42\u4f55\u65f6\u4f1a\u5c1d\u8bd5\u4e2d\u6b62\u547d\u4ee4\uff1f<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4ee5\u4e0b\u60c5\u51b5\u4e0b\uff0cSCSI ML \u53ef\u80fd\u4f1a\u5c1d\u8bd5\u4e2d\u6b62 scsi_cmnd\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>SCSI \u4e2d\u95f4\u5c42\u547d\u4ee4\u8d85\u65f6\uff0c\u5e76\u8bd5\u56fe\u4e2d\u6b62\u5b83\u3002<br \/>scsi_times_out()<br \/>-&gt; scsi_abort_command()<br \/>\u5982\u679c\u4e2d\u6b62\u5931\u8d25\u4f1a\u600e\u6837\uff1f \u4e3a EH \u5b89\u6392\u547d\u4ee4\u3002<\/li>\n\n\n\n<li>EH \u7ebf\u7a0b\u5728\u5c1d\u8bd5\u89e3\u9664\u4e3b\u673a\u963b\u585e\u65f6\u5c1d\u8bd5\u4e2d\u6b62\u6240\u6709\u6302\u8d77\u7684\u547d\u4ee4\u3002<br \/>scsi_unjam_host()<br \/>-&gt; scsi_eh_abort_cmds() \u5982\u679c\u4e2d\u6b62\u5931\u8d25\u4f1a\u600e\u6837\uff1f\u6211\u4eec\u8f6c\u5411\u66f4\u9ad8\u4e25\u91cd\u6027\u7684\u6062\u590d\u6b65\u9aa4\uff08\u5f00\u59cb\u91cd\u7f6e HW \u7ec4\u4ef6\u7b49\uff09\uff0c\u56e0\u4e3a\u8fd9\u53ef\u80fd\u4f1a\u5bfc\u81f4 LLD \u548c HW \u5fd8\u8bb0\u8fd9\u4e9b\u547d\u4ee4\u3002<\/li>\n\n\n\n<li>\u8fd9\u662f\u4e00\u4e2a\u8ba8\u538c\u7684\u4e8b\u3002\u5728\u9519\u8bef\u6062\u590d\u671f\u95f4\uff0cEH \u7ebf\u7a0b\u53ef\u80fd\u4f1a\u201c\u52ab\u6301\u201dscsi_cmnd \u4ee5\u4f7f\u7528 scsi_send_eh_cmnd() \u5411 LLD \u53d1\u9001 EH \u547d\u4ee4\uff08TUR\/STU\/REQ_SENSE\uff09\u3002 \u5982\u679c\u6b64\u7c7b\u201c\u52ab\u6301\u201dEH \u547d\u4ee4\u8d85\u65f6\uff0cSCSI EH \u7ebf\u7a0b\u5c06\u5c1d\u8bd5\u4e2d\u6b62\u5b83\u3002<br \/>scsi_send_eh_cmnd()<br \/>-&gt; scsi_abort_eh_cmnd()<br \/>-&gt; scsi_try_to_abort_cmd() \u5982\u679c\u4e2d\u6b62\u5931\u8d25\u4f1a\u600e\u6837\uff1f\u4e0e\u524d\u4e00\u79cd\u60c5\u51b5\u7c7b\u4f3c\uff0cscsi_abort_eh_cmnd() \u5c06\u5c1d\u8bd5\u91c7\u53d6\u66f4\u9ad8\u4e25\u91cd\u6027\u7684\u64cd\u4f5c\uff08\u91cd\u7f6e\u603b\u7ebf\u7b49\uff09\uff0c\u4f46\u4e0d\u4f1a\u518d\u6b21\u53d1\u9001 EH \u547d\u4ee4\uff08\u4f8b\u5982 TUR \u7b49\uff09\u4ee5\u9a8c\u8bc1\u8bbe\u5907\u662f\u5426\u5f00\u59cb\u54cd\u5e94\u3002 6.2 SCSI \u547d\u4ee4\u4e2d\u6b62\u5982\u4f55\u5de5\u4f5c\uff1f<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0e\u50cf TUR \u8fd9\u6837\u7684 EH \u547d\u4ee4\u4e0d\u540c\uff0cABORT \u4e0d\u662f\u4e2d\u95f4\u5c42\u9a71\u52a8\u7a0b\u5e8f\u53d1\u9001\u7ed9 LLD \u7684 SCSI \u547d\u4ee4\u3002LLD \u63d0\u4f9b\u4e86\u4e00\u4e2a eh_abort_handler() \u51fd\u6570\u6307\u9488\uff0c\u7528\u4e8e\u4e2d\u6b62\u547d\u4ee4\u3002\u7531 LLD \u6765\u505a\u4efb\u4f55\u9700\u8981\u7684\u4e8b\u60c5\u6765\u4e2d\u6b62\u547d\u4ee4\u3002 \u5b83\u53ef\u80fd\u9700\u8981\u5411\u786c\u4ef6\u53d1\u9001\u4e00\u4e9b\u4e13\u6709\u547d\u4ee4\uff0c\u6216\u8005\u4fee\u6539\u4e00\u4e9b\u4f4d\uff0c\u6216\u8005\u505a\u4efb\u4f55\u5fc5\u8981\u7684\u9b54\u672f\u66f4\u6539\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">6.3 \u4e2d\u6b62\u4e5f\u53ef\u80fd\u5931\u8d25<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0e\u5176\u4ed6\u4e8b\u60c5\u4e00\u6837\uff0c\u4e2d\u6b62\u5c1d\u8bd5\u4e5f\u53ef\u80fd\u5931\u8d25\u3002 SCSI \u4e2d\u95f4\u5c42\u5728\u4e0a\u4e00\u8282\u4e2d\u63cf\u8ff0\u7684\u60c5\u51b5\u4e0b\u505a\u6b63\u786e\u7684\u4e8b\u60c5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ce88\uff1a<br \/>\u4e00\u65e6\u5757\u5c42\u5c06\u547d\u4ee4\u4ea4\u7ed9 SCSI \u5b50\u7cfb\u7edf\uff0c\u5757\u5c42\u76ee\u524d\u65e0\u6cd5\u53d6\u6d88\/\u4e2d\u6b62\u8bf7\u6c42\u3002\u8fd9\u9700\u8981\u4e00\u4e9b\u5de5\u4f5c\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\" start=\"7\">\n<li>SCSI \u547d\u4ee4\u91cd\u8bd5 SCSI \u4e2d\u95f4\u5c42\u4e0d\u4e3a\u5176\u6b63\u5728\u5904\u7406\u7684 SCSI \u547d\u4ee4\u7ef4\u62a4\u4efb\u4f55\u961f\u5217\uff08EH \u547d\u4ee4\u961f\u5217\u9664\u5916\uff09\u3002 \u56e0\u6b64\uff0c\u6bcf\u5f53 SCSI ML \u8ba4\u4e3a\u5b83\u9700\u8981\u91cd\u8bd5\u547d\u4ee4\u65f6\uff0c\u5b83\u4f1a\u5c06\u8bf7\u6c42\u91cd\u65b0\u6392\u961f\u8fd4\u56de\u5230\u76f8\u5e94\u7684\u8bf7\u6c42\u961f\u5217\uff0c\u4ee5\u4fbf\u5728\u8bf7\u6c42\u51fd\u6570\u9009\u62e9\u4e0b\u4e00\u4e2a\u8bf7\u6c42\u8fdb\u884c\u5904\u7406\u65f6\u201c\u81ea\u7136\u5730\u201d\u8fdb\u884c\u91cd\u8bd5\u3002 \u5f53\u5c06\u6b64\u7c7b\u8bf7\u6c42\u8981\u8bf7\u6c42\u56de\u5230\u8bf7\u6c42\u961f\u5217\u65f6\uff0c\u5b83\u4eec\u88ab\u653e\u5728\u8bf7\u6c42\u961f\u5217\u7684\u5934\u90e8\uff0c\u4ee5\u4fbf\u5b83\u4eec\u5728\u8be5\u961f\u5217\u4e2d\u7684\u5176\u4ed6\uff08\u73b0\u6709\uff09\u8bf7\u6c42\u4e4b\u524d\u3002 7.1 \u4e2d\u95f4\u5c42\u4f55\u65f6\u4f1a\u91cd\u8bd5\u547d\u4ee4\uff1f<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee5\u4e0b\u662f\u5bfc\u81f4\u91cd\u8bd5 SCSI \u547d\u4ee4\u7684\u6761\u4ef6\uff08\u901a\u8fc7\u5c06 blk \u8bf7\u6c42\u653e\u56de\u8bf7\u6c42\u961f\u5217\uff09\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u4e2d\u95f4\u5c42\u5728 scsi_cmnd \u4e0a\u8d85\u65f6\uff0c\u6210\u529f\u4e2d\u6b62\u5e76\u91cd\u65b0\u6392\u961f\u3002<br \/>scsi_times_out()<br \/>-&gt; scsi_abort_command()<br \/>-&gt; \u8c03\u5ea6 scmd_eh_abort_handler()<br \/>-&gt; scsi_queue_insert()<br \/>-&gt; blk_requeue_request()<\/li>\n\n\n\n<li>EH \u7ebf\u7a0b\u5728\u6062\u590d\u4e3b\u673a\u540e\uff0c\u91cd\u65b0\u6392\u961f\u6240\u6709\u7b26\u5408\u91cd\u8bd5\u6761\u4ef6\u7684 scsi_cmnd\uff1a<br \/>scsi_error_handler()<br \/>-&gt; scsi_unjam_host()<br \/>-&gt; scsi_eh_flush_done_q()<br \/>-&gt; scsi_queue_insert()<br \/>-&gt; blk_requeue_request()<\/li>\n\n\n\n<li>LLD \u5b8c\u6210 scsi_cmnd\uff0cscsi_decide_disposition() \u67e5\u770b scsi_cmnd-&gt;result \u5e76\u8ba4\u4e3a\u9700\u8981\u91cd\u8bd5\uff08\u4f8b\u5982\uff0c\u56e0\u4e3a\u603b\u7ebf\u7e41\u5fd9\uff09\u3002<br \/>scsi_softirq_done()<br \/>-&gt; scsi_decide_disposition() \u8fd4\u56de NEEDS_RETRY<br \/>-&gt; scsi_queue_insert()<br \/>-&gt; blk_requeue_request()<\/li>\n\n\n\n<li>\u5728 scsi_request_fn() \u4e2d\uff0cSCSI ML \u53d1\u73b0\u4e3b\u673a\u6b63\u5fd9\uff0cscsi_cmnd \u65e0\u6cd5\u53d1\u9001\u5230 LLD\uff0c\u56e0\u6b64\u5b83\u5c06\u8bf7\u6c42\u91cd\u65b0\u6392\u56de\u961f\u5217\u3002<br \/>scsi_request_fn()<br \/>-&gt;\u6848\u4f8bnote_ready\uff1a<br \/>-&gt; blk_requeue_request()<\/li>\n\n\n\n<li>scsi_finish_command() \u53ef\u4ee5\u4ece\u591a\u4e2a\u5730\u65b9\u88ab\u8c03\u7528\u4ee5\u5b8c\u6210\u5bf9\u5757\u7ea7\u522b\u7684\u8bf7\u6c42\u3002\u4f46\u662f\uff0c\u5b83\u4e5f\u53ef\u80fd\u4f1a\u8c03\u7528 scsi_io_completion() \u6765\u67e5\u770b\u8bf7\u6c42\u5e76\u51b3\u5b9a\u91cd\u8bd5\uff08\u5982\u679c\u7b26\u5408\u6761\u4ef6\uff09\u3002<br \/>scsi_finish_command()<br \/>-&gt; scsi_io_completion()<br \/>-&gt; __scsi_queue_insert()<br \/>-&gt; blk_requeue_request() \u6ce8 9\uff1a<br \/>\u4e0a\u9762\u7684\u60c5\u51b5 5 \u6709\u4e00\u4e2a\u975e\u5e38\u7279\u6b8a\u7684\u60c5\u51b5\u3002\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0cscsi_io_completion() \u51b3\u5b9a\u5fc5\u987b\u91cd\u8bd5 blk \u8bf7\u6c42\uff0c\u4f46\u662f\u5e94\u8be5\u91ca\u653e\u6b64\u8bf7\u6c42\u7684 scsi_cmnd\uff0c\u800c\u662f\u5e94\u8be5\u5206\u914d\u4e00\u4e2a\u65b0\u7684 scsi_cmnd \u5e76\u5728\u4e0b\u4e00\u6b21\u91cd\u8bd5\u65f6\u7528\u4e8e\u6b64\u8bf7\u6c42\u3002\u4f8b\u5982\uff0c\u60c5\u51b5\u53ef\u80fd\u5c31\u662f\u8fd9\u6837\uff1a\u5982\u679c\u5b83\u770b\u5230 ILLEGAL REQUEST \u4f5c\u4e3a\u5bf9 READ10 \u547d\u4ee4\u7684\u54cd\u5e94\uff0c\u5e76\u8ba4\u4e3a\u8fd9\u53ef\u80fd\u662f\u56e0\u4e3a\u8bbe\u5907\u4ec5\u652f\u6301 READ6\u3002\u56e0\u6b64\uff0c\u5728\u4e0b\u6b21\u91cd\u8bd5\u65f6\u5207\u6362\u5230 READ6\uff08\u56e0\u6b64\u662f\u4e00\u4e2a\u65b0\u7684 scsi_cmnd\uff09\u53ef\u80fd\u662f\u6709\u610f\u4e49\u7684\u3002 7.2 \u91cd\u8bd5\u8d44\u683c\u6807\u51c6<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u8bf7\u6ce8\u610f\uff0cSCSI \u4e2d\u95f4\u5c42\u603b\u662f\u5728\u7ee7\u7eed\u4e4b\u524d\u68c0\u67e5\u91cd\u8bd5\u8d44\u683c\u5e76\u91cd\u65b0\u6392\u961f\u547d\u4ee4\u4ee5\u8fdb\u884c\u91cd\u8bd5\u3002 scsi_cmnd \u7684\u8d44\u683c\u6807\u51c6\u5305\u62ec\uff08\u5176\u4e2d\u4e00\u4e9b\u53ef\u80fd\u4e0d\u9002\u7528\u4e8e\u4e0a\u8ff0\u6240\u6709\u60c5\u51b5\uff09\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>retries &lt; allowed (Num of retries should be less than allowed retries\uff0c\u5373\u5df2\u91cd\u8bd5\u7684\u6b21\u6570\u5e94\u5c11\u4e8e\u5141\u8bb8\u7684\u6700\u5927\u91cd\u8bd5\u6b21\u6570)<\/li>\n\n\n\n<li>\u82b1\u8d39\u5728 EH \u7684\u65f6\u95f4\u4e0d\u8d85\u8fc7 host-&gt;eh_deadline jiffies<\/li>\n\n\n\n<li>scsi_noretry_cmd() \u5e94\u8be5\u4e3a\u547d\u4ee4\u8fd4\u56de 0\u3002<\/li>\n\n\n\n<li>scsi_device \u5fc5\u987b\u5728\u7ebf<\/li>\n\n\n\n<li>req-&gt;timeout \u4e0d\u80fd\u8fc7\u671f<\/li>\n\n\n\n<li>\u7b49\u7b49\u3002\u3002\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u793a\u4f8b\uff1a\u4ee5\u4e00\u4e2a scsi_cmnd \u8fc7\u7a0b\u4e3a\u4f8b 8.1 \u793a\u4f8b scsi_cmnd \u6240\u7528\u8def\u5f84\u7684\u9ad8\u7ea7\u89c6\u56fe<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u4ee5\u5757\u8bf7\u6c42\u4e3a\u4f8b\uff0c\u4f8b\u5982\u60f3\u8981\u4ece scsi \u78c1\u76d8\u8bfb\u53d6\u5757\uff0c\u4f46\u662f LBA \u5730\u5740\u8d85\u51fa\u5f53\u524d\u8bbe\u5907\u7684\u8303\u56f4\uff08\u5047\u8bbe\uff09\u3002 ML \u5c06\u5176\u63d0\u4ea4\u7ed9 LLD\uff0c\u4f46 HW \u63a5\u53d7\u547d\u4ee4\u5e76\u5728\u5176\u4e0a\u963b\u585e\uff08\u518d\u6b21\u5047\u8bbe\u901a\u8fc7\u4e2d\u6b62\u5e8f\u5217\u8fdb\u884c\u8ddf\u8e2a\uff09\u3002\u6240\u4ee5\u8d85\u65f6\u53d1\u751f\uff0cML \u4e2d\u6b62\u547d\u4ee4\uff0c\u5e76\u91cd\u65b0\u6392\u961f\u3002\u5728\u4e0b\u4e00\u6b21\u8fd0\u884c\u4e2d\uff0cLLD \u4f7f\u7528 CHECK_CONDITION \u5b8c\u6210\u547d\u4ee4\u3002\u6211\u4eec\u5047\u8bbe SCSI \u4e3b\u673a\u4e0d\u4f1a\u81ea\u52a8\u83b7\u53d6\u611f\u77e5\u4fe1\u606f\u3002ML \u4e3a EH \u8c03\u5ea6 cmnd\u3002EH\u7ebf\u7a0b\u53d1\u9001REQUEST_SENSE \u83b7\u53d6 sense info ILLEGAL_REQUEST\uff0c\u5e76\u636e\u6b64\u5b8c\u6210\u5bf9block\u5c42\u7684\u8bf7\u6c42\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">8.2 \u5b9e\u9645\u91c7\u53d6\u7684\u8def\u5f84<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">Dispatched \u6d3e\u53d1\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_request_fn()<br \/>|<br \/>+&#8212;&gt; blk_peek_request()<br \/>| |<br \/>| +&#8212;&gt; scsi_prep_fn()<br \/>| \uff08\u5206\u914d\u548c\u8bbe\u7f6e scsi_cmnd\uff09<br \/>|<br \/>+&#8212;&gt; scsi_dispatch_cmd()<br \/>|<br \/>+&#8212;&gt; hostt-&gt;queue_command()<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8d85\u65f6\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_times_out()<br \/>|<br \/>+&#8212;&gt; scsi_abort_command() &#8211; \u8fd4\u56de\u6210\u529f\uff08SUCCESS\uff09<br \/>|<br \/>+&#8212;&gt; queue_delayed_work(abort_work) \uff0c\u961f\u5217\u5ef6\u8fdf\u5de5\u4f5c\uff08\u4e2d\u6b62\u5de5\u4f5c\uff09<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e2d\u6b62\u5904\u7406\u7a0b\u5e8f\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scmd_eh_abort_handler()<br \/>|<br \/>+&#8212;&gt; scsi_try_to_abort_cmd() &#8211; \u8fd4\u56de\u6210\u529f\uff08SUCCESS\uff09<br \/>| |<br \/>| +&#8212;&gt; hostt-&gt;eh_abort_handler()<br \/>|<br \/>+&#8212;&gt; scsi_queue_insert()<br \/>|<br \/>+&#8212;&gt; __scsi_queue_insert()<br \/>|<br \/>+&#8212;&gt; blk_requeue_request()<br \/>\uff08req \u88ab\u91cd\u65b0\u6392\u961f\uff0creq-&gt;special \u6307\u5411 scsi_cmnd\uff09<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u518d\u6b21\u6536\u5230\u8bf7\u6c42\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_request_fn()<br \/>|<br \/>+&#8212;&gt; blk_peek_request()<br \/>| \uff08req-&gt;cmd_flags \u8bbe\u7f6e\u4e86 REQ_DONTPREP\uff0c\u56e0\u6b64\u4e0d\u4f1a\u518d\u6b21\u8c03\u7528 scsi_prep_fn()\uff09<br \/>|<br \/>+&#8212;&gt; scsi_dispatch_cmd()<br \/>|<br \/>+&#8212;&gt; hostt-&gt;queue_command()<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u547d\u4ee4\u4ee5 CHECK_CONDITION \u5b8c\u6210\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_softirq_done()<br \/>|<br \/>+&#8212;&gt; scsi_decide_disposition()<br \/>| \uff08\u67e5\u770b CHECK_CONDITION\uff09<br \/>| |<br \/>| +&#8212;&gt; scsi_check_sense() &#8211; \u8fd4\u56de\u5931\u8d25<br \/>| |<br \/>| +&#8212;&gt; scsi_command_normalize_sense()<br \/>| \uff08\u672a\u80fd\u627e\u5230\u6709\u6548\u7684\u611f\u77e5\u6570\u636e\uff09<br \/>|<br \/>+&#8212;&gt; \u8fd4\u56de\u7ed3\u679c\u4e3a \u5931\u8d25\uff08FAILED\uff09\uff1a<br \/>|<br \/>+&#8212;&gt; scsi_eh_scmd_add()<br \/>\u5c06 scsi_cmnd \u6dfb\u52a0\u5230\u4e3b\u673a EH \u961f\u5217<br \/>|<br \/>+&#8212;&gt; scsi_eh_wakeup()<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SCSI \u9519\u8bef\u5904\u7406\u7a0b\u5e8f\u7ebf\u7a0b\u8fd0\u884c\u4ee5\u83b7\u53d6\u611f\u77e5\u4fe1\u606f\uff0c\u5e76\u5728\u5176\u6267\u884c\u5b8c\u6210\u540e\u5b8c\u6210\u8bf7\u6c42\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scsi_error_handler()<br \/>|<br \/>+&#8212;&gt; scsi_unjam_host()<br \/>|<br \/>+&#8212;&gt; scsi_eh_get_sense()<br \/>| |<br \/>| +&#8212;&gt; scsi_request_sense()<br \/>| | |<br \/>| | +&#8212;&gt; scsi_send_eh_cmnd()<br \/>| | \uff08\u52ab\u6301 smnd \u53d1\u9001 EH \u547d\u4ee4\uff09<br \/>| | |<br \/>| | +&#8211;&gt; scsi_eh_prep_cmnd()<br \/>| | | \uff08\u4fdd\u5b58\u73b0\u6709 scsi_cmndi \u7684\u4e0a\u4e0b\u6587\uff0c\u5206\u914d sence \u611f\u77e5\u6570\u636e\u7f13\u51b2\u533a\uff0c\u5e76\u4e3a REQUEST_SENSE \u8bbe\u7f6e scsi_cmnd\uff09<br \/>| | |<br \/>| | +&#8211;&gt; hostt-&gt;queuecommand()\uff0c\u7136\u540e\u7b49\u5f85\u2026<br \/>| | | \uff08\u83b7\u53d6 cmnd \u7684\u611f\u77e5\u6570\u636e\uff09<br \/>| | |<br \/>| | +&#8211;&gt; scsi_eh_completed_normally() &#8211; \u8fd4\u56de\u6210\u529f<br \/>| | |<br \/>| | +&#8211;&gt; scsi_eh_restore_cmnd()<br \/>| | \uff08\u6062\u590d\u539f\u59cb scsi_cmnd \u7684\u4e0a\u4e0b\u6587\uff09<br \/>| |<br \/>| +&#8212;&gt; scsi_decide_disposition() &#8211; \u8fd4\u56de\u6210\u529f<br \/>| | \uff08\u6b64\u65f6\u53ef\u4ee5\u770b\u5230sense info\uff09<br \/>| |<br \/>| +&#8212;&gt; \u8bbe\u7f6e scmd-&gt;retries = scmd-&gt;allowed\uff08\u907f\u514d\u91cd\u8bd5\uff09<br \/>| |<br \/>| +&#8212;&gt; scsi_eh_finish_cmd()<br \/>| \uff08\u5c06 scsi_cmnd \u653e\u5728 done_q \u4e0a\uff09<br \/>|<br \/>+&#8212;&gt; scsi_eh_flush_done_q()<br \/>\uff08\u770b\u5230 scsi_cmnd \u4e0d\u7b26\u5408\u91cd\u8bd5\u6761\u4ef6\uff09<br \/>|<br \/>+&#8212;&gt; scsi_finish_command()<br \/>|<br \/>+&#8212;&gt; scsi_io_completion()<br \/>|<br \/>+&#8212;&gt; scsi_end_request()<br \/>|<br \/>+&#8212;&gt; scsi_put_command()<br \/>\uff08\u91ca\u653e scsi_cmnd\uff09<\/p>\n\n\n\n<ol class=\"wp-block-list\" start=\"9\">\n<li>\u53c2\u8003\u6587\u732e<br \/>==========<br \/>\u4ee5\u4e0b\u662f\u6781\u597d\u7684\u53c2\u8003\u8d44\u6599\u6765\u6e90\uff1a<br \/>Documentation\/scsi\/scsi_eh.txt<\/li>\n<\/ol>\n\n\n\n<h2 class=\"has-small-font-size wp-block-heading\">http:\/\/events.linuxfoundation.org\/sites\/events\/files\/slides\/SCSI-EH.pdf &lt;===<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u8865\u6ce8 2:<br \/>\u4e0a\u8ff0 SCSI-EH.pdf \u539f\u94fe\u63a5\u5931\u6548\uff0c\u6839\u636e\u5185\u5bb9\u63a8\u65ad\uff0c\u5e94\u4e3a\u5982\u4e0b\u94fe\u63a5\uff1a<br \/>http:\/\/events17.linuxfoundation.org\/sites\/events\/files\/slides\/SCSI-EH.pdf<\/p>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"http:\/\/fudong.tech\/wp-content\/uploads\/2023\/03\/SCSI-\u547d\u4ee4\uff08scsi_cmnd\uff09\u7684\u751f\u547d\u5468\u671f-4.0v1.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"\u5d4c\u5165 SCSI-\u547d\u4ee4\uff08scsi_cmnd\uff09\u7684\u751f\u547d\u5468\u671f-4.0v1\"><\/object><a id=\"wp-block-file--media-c7a7a2e4-365d-4d30-9345-13389b327da2\" href=\"http:\/\/fudong.tech\/wp-content\/uploads\/2023\/03\/SCSI-\u547d\u4ee4\uff08scsi_cmnd\uff09\u7684\u751f\u547d\u5468\u671f-4.0v1.pdf\">SCSI-\u547d\u4ee4\uff08scsi_cmnd\uff09\u7684\u751f\u547d\u5468\u671f-4.0v1<\/a><a href=\"http:\/\/fudong.tech\/wp-content\/uploads\/2023\/03\/SCSI-\u547d\u4ee4\uff08scsi_cmnd\uff09\u7684\u751f\u547d\u5468\u671f-4.0v1.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-c7a7a2e4-365d-4d30-9345-13389b327da2\">\u4e0b\u8f7d<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7ffb\u8bd1\u4e8e 2023\u5e743\u670815\u65e5 | &amp;&amp;&amp; \u7ffb\u8bd1\u8bf4\u660e &amp;&amp;&amp; | [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18,4],"tags":[],"class_list":["post-54","post","type-post","status-publish","format-standard","hentry","category-linux","category-storage"],"_links":{"self":[{"href":"http:\/\/fudong.tech\/index.php?rest_route=\/wp\/v2\/posts\/54","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/fudong.tech\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/fudong.tech\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/fudong.tech\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/fudong.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=54"}],"version-history":[{"count":0,"href":"http:\/\/fudong.tech\/index.php?rest_route=\/wp\/v2\/posts\/54\/revisions"}],"wp:attachment":[{"href":"http:\/\/fudong.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=54"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/fudong.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=54"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/fudong.tech\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=54"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}