1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Chapter&#160;14.&#160;Block Devices</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The Linux Kernel API"><link rel="up" href="index.html" title="The Linux Kernel API"><link rel="prev" href="API-acct-process.html" title="acct_process"><link rel="next" href="API-blk-get-backing-dev-info.html" title="blk_get_backing_dev_info"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter&#160;14.&#160;Block Devices</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-acct-process.html">Prev</a>&#160;</td><th width="60%" align="center">&#160;</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-blk-get-backing-dev-info.html">Next</a></td></tr></table><hr></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="blkdev"></a>Chapter&#160;14.&#160;Block Devices</h1></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl class="toc"><dt><span class="refentrytitle"><a href="API-blk-get-backing-dev-info.html"><span class="phrase">blk_get_backing_dev_info</span></a></span><span class="refpurpose"> &#8212; 
2  get the address of a queue's backing_dev_info
3 </span></dt><dt><span class="refentrytitle"><a href="API-blk-delay-queue.html"><span class="phrase">blk_delay_queue</span></a></span><span class="refpurpose"> &#8212; 
4     restart queueing after defined interval
5 </span></dt><dt><span class="refentrytitle"><a href="API-blk-start-queue.html"><span class="phrase">blk_start_queue</span></a></span><span class="refpurpose"> &#8212; 
6     restart a previously stopped queue
7 </span></dt><dt><span class="refentrytitle"><a href="API-blk-stop-queue.html"><span class="phrase">blk_stop_queue</span></a></span><span class="refpurpose"> &#8212; 
8     stop a queue
9 </span></dt><dt><span class="refentrytitle"><a href="API-blk-sync-queue.html"><span class="phrase">blk_sync_queue</span></a></span><span class="refpurpose"> &#8212; 
10     cancel any pending callbacks on a queue
11 </span></dt><dt><span class="refentrytitle"><a href="API---blk-run-queue.html"><span class="phrase">__blk_run_queue</span></a></span><span class="refpurpose"> &#8212; 
12     run a single device queue
13 </span></dt><dt><span class="refentrytitle"><a href="API-blk-run-queue-async.html"><span class="phrase">blk_run_queue_async</span></a></span><span class="refpurpose"> &#8212; 
14     run a single device queue in workqueue context
15 </span></dt><dt><span class="refentrytitle"><a href="API-blk-run-queue.html"><span class="phrase">blk_run_queue</span></a></span><span class="refpurpose"> &#8212; 
16     run a single device queue
17 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-bypass-start.html"><span class="phrase">blk_queue_bypass_start</span></a></span><span class="refpurpose"> &#8212; 
18     enter queue bypass mode
19 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-bypass-end.html"><span class="phrase">blk_queue_bypass_end</span></a></span><span class="refpurpose"> &#8212; 
20     leave queue bypass mode
21 </span></dt><dt><span class="refentrytitle"><a href="API-blk-cleanup-queue.html"><span class="phrase">blk_cleanup_queue</span></a></span><span class="refpurpose"> &#8212; 
22     shutdown a request queue
23 </span></dt><dt><span class="refentrytitle"><a href="API-blk-init-queue.html"><span class="phrase">blk_init_queue</span></a></span><span class="refpurpose"> &#8212; 
24     prepare a request queue for use with a block device
25 </span></dt><dt><span class="refentrytitle"><a href="API-blk-make-request.html"><span class="phrase">blk_make_request</span></a></span><span class="refpurpose"> &#8212; 
26     given a bio, allocate a corresponding struct request.
27 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-set-block-pc.html"><span class="phrase">blk_rq_set_block_pc</span></a></span><span class="refpurpose"> &#8212; 
28     initialize a request to type BLOCK_PC
29 </span></dt><dt><span class="refentrytitle"><a href="API-blk-requeue-request.html"><span class="phrase">blk_requeue_request</span></a></span><span class="refpurpose"> &#8212; 
30     put a request back on queue
31 </span></dt><dt><span class="refentrytitle"><a href="API-part-round-stats.html"><span class="phrase">part_round_stats</span></a></span><span class="refpurpose"> &#8212; 
32     Round off the performance stats on a struct disk_stats.
33 </span></dt><dt><span class="refentrytitle"><a href="API-blk-add-request-payload.html"><span class="phrase">blk_add_request_payload</span></a></span><span class="refpurpose"> &#8212; 
34     add a payload to a request
35 </span></dt><dt><span class="refentrytitle"><a href="API-generic-make-request.html"><span class="phrase">generic_make_request</span></a></span><span class="refpurpose"> &#8212; 
36     hand a buffer to its device driver for I/O
37 </span></dt><dt><span class="refentrytitle"><a href="API-submit-bio.html"><span class="phrase">submit_bio</span></a></span><span class="refpurpose"> &#8212; 
38     submit a bio to the block device layer for I/O
39 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-check-limits.html"><span class="phrase">blk_rq_check_limits</span></a></span><span class="refpurpose"> &#8212; 
40     Helper function to check a request for the queue limit
41 </span></dt><dt><span class="refentrytitle"><a href="API-blk-insert-cloned-request.html"><span class="phrase">blk_insert_cloned_request</span></a></span><span class="refpurpose"> &#8212; 
42     Helper for stacking drivers to submit a request
43 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-err-bytes.html"><span class="phrase">blk_rq_err_bytes</span></a></span><span class="refpurpose"> &#8212; 
44     determine number of bytes till the next failure boundary
45 </span></dt><dt><span class="refentrytitle"><a href="API-blk-peek-request.html"><span class="phrase">blk_peek_request</span></a></span><span class="refpurpose"> &#8212; 
46     peek at the top of a request queue
47 </span></dt><dt><span class="refentrytitle"><a href="API-blk-start-request.html"><span class="phrase">blk_start_request</span></a></span><span class="refpurpose"> &#8212; 
48     start request processing on the driver
49 </span></dt><dt><span class="refentrytitle"><a href="API-blk-fetch-request.html"><span class="phrase">blk_fetch_request</span></a></span><span class="refpurpose"> &#8212; 
50     fetch a request from a request queue
51 </span></dt><dt><span class="refentrytitle"><a href="API-blk-update-request.html"><span class="phrase">blk_update_request</span></a></span><span class="refpurpose"> &#8212; 
52     Special helper function for request stacking drivers
53 </span></dt><dt><span class="refentrytitle"><a href="API-blk-unprep-request.html"><span class="phrase">blk_unprep_request</span></a></span><span class="refpurpose"> &#8212; 
54     unprepare a request
55 </span></dt><dt><span class="refentrytitle"><a href="API-blk-end-request.html"><span class="phrase">blk_end_request</span></a></span><span class="refpurpose"> &#8212; 
56     Helper function for drivers to complete the request.
57 </span></dt><dt><span class="refentrytitle"><a href="API-blk-end-request-all.html"><span class="phrase">blk_end_request_all</span></a></span><span class="refpurpose"> &#8212; 
58     Helper function for drives to finish the request.
59 </span></dt><dt><span class="refentrytitle"><a href="API-blk-end-request-cur.html"><span class="phrase">blk_end_request_cur</span></a></span><span class="refpurpose"> &#8212; 
60     Helper function to finish the current request chunk.
61 </span></dt><dt><span class="refentrytitle"><a href="API-blk-end-request-err.html"><span class="phrase">blk_end_request_err</span></a></span><span class="refpurpose"> &#8212; 
62     Finish a request till the next failure boundary.
63 </span></dt><dt><span class="refentrytitle"><a href="API---blk-end-request.html"><span class="phrase">__blk_end_request</span></a></span><span class="refpurpose"> &#8212; 
64     Helper function for drivers to complete the request.
65 </span></dt><dt><span class="refentrytitle"><a href="API---blk-end-request-all.html"><span class="phrase">__blk_end_request_all</span></a></span><span class="refpurpose"> &#8212; 
66     Helper function for drives to finish the request.
67 </span></dt><dt><span class="refentrytitle"><a href="API---blk-end-request-cur.html"><span class="phrase">__blk_end_request_cur</span></a></span><span class="refpurpose"> &#8212; 
68     Helper function to finish the current request chunk.
69 </span></dt><dt><span class="refentrytitle"><a href="API---blk-end-request-err.html"><span class="phrase">__blk_end_request_err</span></a></span><span class="refpurpose"> &#8212; 
70     Finish a request till the next failure boundary.
71 </span></dt><dt><span class="refentrytitle"><a href="API-rq-flush-dcache-pages.html"><span class="phrase">rq_flush_dcache_pages</span></a></span><span class="refpurpose"> &#8212; 
72     Helper function to flush all pages in a request
73 </span></dt><dt><span class="refentrytitle"><a href="API-blk-lld-busy.html"><span class="phrase">blk_lld_busy</span></a></span><span class="refpurpose"> &#8212; 
74     Check if underlying low-level drivers of a device are busy
75 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-unprep-clone.html"><span class="phrase">blk_rq_unprep_clone</span></a></span><span class="refpurpose"> &#8212; 
76     Helper function to free all bios in a cloned request
77 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-prep-clone.html"><span class="phrase">blk_rq_prep_clone</span></a></span><span class="refpurpose"> &#8212; 
78     Helper function to setup clone request
79 </span></dt><dt><span class="refentrytitle"><a href="API-blk-start-plug.html"><span class="phrase">blk_start_plug</span></a></span><span class="refpurpose"> &#8212; 
80     initialize blk_plug and track it inside the task_struct
81 </span></dt><dt><span class="refentrytitle"><a href="API-blk-pm-runtime-init.html"><span class="phrase">blk_pm_runtime_init</span></a></span><span class="refpurpose"> &#8212; 
82     Block layer runtime PM initialization routine
83 </span></dt><dt><span class="refentrytitle"><a href="API-blk-pre-runtime-suspend.html"><span class="phrase">blk_pre_runtime_suspend</span></a></span><span class="refpurpose"> &#8212; 
84     Pre runtime suspend check
85 </span></dt><dt><span class="refentrytitle"><a href="API-blk-post-runtime-suspend.html"><span class="phrase">blk_post_runtime_suspend</span></a></span><span class="refpurpose"> &#8212; 
86     Post runtime suspend processing
87 </span></dt><dt><span class="refentrytitle"><a href="API-blk-pre-runtime-resume.html"><span class="phrase">blk_pre_runtime_resume</span></a></span><span class="refpurpose"> &#8212; 
88     Pre runtime resume processing
89 </span></dt><dt><span class="refentrytitle"><a href="API-blk-post-runtime-resume.html"><span class="phrase">blk_post_runtime_resume</span></a></span><span class="refpurpose"> &#8212; 
90     Post runtime resume processing
91 </span></dt><dt><span class="refentrytitle"><a href="API---blk-run-queue-uncond.html"><span class="phrase">__blk_run_queue_uncond</span></a></span><span class="refpurpose"> &#8212; 
92  run a queue whether or not it has been stopped
93 </span></dt><dt><span class="refentrytitle"><a href="API---blk-drain-queue.html"><span class="phrase">__blk_drain_queue</span></a></span><span class="refpurpose"> &#8212; 
94     drain requests from request_queue
95 </span></dt><dt><span class="refentrytitle"><a href="API-rq-ioc.html"><span class="phrase">rq_ioc</span></a></span><span class="refpurpose"> &#8212; 
96     determine io_context for request allocation
97 </span></dt><dt><span class="refentrytitle"><a href="API---get-request.html"><span class="phrase">__get_request</span></a></span><span class="refpurpose"> &#8212; 
98     get a free request
99 </span></dt><dt><span class="refentrytitle"><a href="API-get-request.html"><span class="phrase">get_request</span></a></span><span class="refpurpose"> &#8212; 
100     get a free request
101 </span></dt><dt><span class="refentrytitle"><a href="API-blk-attempt-plug-merge.html"><span class="phrase">blk_attempt_plug_merge</span></a></span><span class="refpurpose"> &#8212; 
102     try to merge with <code class="constant">current</code>'s plugged list
103 </span></dt><dt><span class="refentrytitle"><a href="API-blk-end-bidi-request.html"><span class="phrase">blk_end_bidi_request</span></a></span><span class="refpurpose"> &#8212; 
104     Complete a bidi request
105 </span></dt><dt><span class="refentrytitle"><a href="API---blk-end-bidi-request.html"><span class="phrase">__blk_end_bidi_request</span></a></span><span class="refpurpose"> &#8212; 
106     Complete a bidi request with queue lock held
107 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-map-user-iov.html"><span class="phrase">blk_rq_map_user_iov</span></a></span><span class="refpurpose"> &#8212; 
108  map user data to a request, for REQ_TYPE_BLOCK_PC usage
109 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-unmap-user.html"><span class="phrase">blk_rq_unmap_user</span></a></span><span class="refpurpose"> &#8212; 
110     unmap a request with user data
111 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-map-kern.html"><span class="phrase">blk_rq_map_kern</span></a></span><span class="refpurpose"> &#8212; 
112     map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
113 </span></dt><dt><span class="refentrytitle"><a href="API-blk-release-queue.html"><span class="phrase">blk_release_queue</span></a></span><span class="refpurpose"> &#8212; 
114  release a <span class="structname">struct request_queue</span> when it is no longer needed
115 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-prep-rq.html"><span class="phrase">blk_queue_prep_rq</span></a></span><span class="refpurpose"> &#8212; 
116  set a prepare_request function for queue
117 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-unprep-rq.html"><span class="phrase">blk_queue_unprep_rq</span></a></span><span class="refpurpose"> &#8212; 
118     set an unprepare_request function for queue
119 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-merge-bvec.html"><span class="phrase">blk_queue_merge_bvec</span></a></span><span class="refpurpose"> &#8212; 
120     set a merge_bvec function for queue
121 </span></dt><dt><span class="refentrytitle"><a href="API-blk-set-default-limits.html"><span class="phrase">blk_set_default_limits</span></a></span><span class="refpurpose"> &#8212; 
122     reset limits to default values
123 </span></dt><dt><span class="refentrytitle"><a href="API-blk-set-stacking-limits.html"><span class="phrase">blk_set_stacking_limits</span></a></span><span class="refpurpose"> &#8212; 
124     set default limits for stacking devices
125 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-make-request.html"><span class="phrase">blk_queue_make_request</span></a></span><span class="refpurpose"> &#8212; 
126     define an alternate make_request function for a device
127 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-bounce-limit.html"><span class="phrase">blk_queue_bounce_limit</span></a></span><span class="refpurpose"> &#8212; 
128     set bounce buffer limit for queue
129 </span></dt><dt><span class="refentrytitle"><a href="API-blk-limits-max-hw-sectors.html"><span class="phrase">blk_limits_max_hw_sectors</span></a></span><span class="refpurpose"> &#8212; 
130     set hard and soft limit of max sectors for request
131 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-max-hw-sectors.html"><span class="phrase">blk_queue_max_hw_sectors</span></a></span><span class="refpurpose"> &#8212; 
132     set max sectors for a request for this queue
133 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-chunk-sectors.html"><span class="phrase">blk_queue_chunk_sectors</span></a></span><span class="refpurpose"> &#8212; 
134     set size of the chunk for this queue
135 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-max-discard-sectors.html"><span class="phrase">blk_queue_max_discard_sectors</span></a></span><span class="refpurpose"> &#8212; 
136     set max sectors for a single discard
137 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-max-write-same-sectors.html"><span class="phrase">blk_queue_max_write_same_sectors</span></a></span><span class="refpurpose"> &#8212; 
138     set max sectors for a single write same
139 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-max-segments.html"><span class="phrase">blk_queue_max_segments</span></a></span><span class="refpurpose"> &#8212; 
140     set max hw segments for a request for this queue
141 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-max-segment-size.html"><span class="phrase">blk_queue_max_segment_size</span></a></span><span class="refpurpose"> &#8212; 
142     set max segment size for blk_rq_map_sg
143 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-logical-block-size.html"><span class="phrase">blk_queue_logical_block_size</span></a></span><span class="refpurpose"> &#8212; 
144     set logical block size for the queue
145 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-physical-block-size.html"><span class="phrase">blk_queue_physical_block_size</span></a></span><span class="refpurpose"> &#8212; 
146     set physical block size for the queue
147 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-alignment-offset.html"><span class="phrase">blk_queue_alignment_offset</span></a></span><span class="refpurpose"> &#8212; 
148     set physical block alignment offset
149 </span></dt><dt><span class="refentrytitle"><a href="API-blk-limits-io-min.html"><span class="phrase">blk_limits_io_min</span></a></span><span class="refpurpose"> &#8212; 
150     set minimum request size for a device
151 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-io-min.html"><span class="phrase">blk_queue_io_min</span></a></span><span class="refpurpose"> &#8212; 
152     set minimum request size for the queue
153 </span></dt><dt><span class="refentrytitle"><a href="API-blk-limits-io-opt.html"><span class="phrase">blk_limits_io_opt</span></a></span><span class="refpurpose"> &#8212; 
154     set optimal request size for a device
155 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-io-opt.html"><span class="phrase">blk_queue_io_opt</span></a></span><span class="refpurpose"> &#8212; 
156     set optimal request size for the queue
157 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-stack-limits.html"><span class="phrase">blk_queue_stack_limits</span></a></span><span class="refpurpose"> &#8212; 
158     inherit underlying queue limits for stacked drivers
159 </span></dt><dt><span class="refentrytitle"><a href="API-blk-stack-limits.html"><span class="phrase">blk_stack_limits</span></a></span><span class="refpurpose"> &#8212; 
160     adjust queue_limits for stacked devices
161 </span></dt><dt><span class="refentrytitle"><a href="API-bdev-stack-limits.html"><span class="phrase">bdev_stack_limits</span></a></span><span class="refpurpose"> &#8212; 
162     adjust queue limits for stacked drivers
163 </span></dt><dt><span class="refentrytitle"><a href="API-disk-stack-limits.html"><span class="phrase">disk_stack_limits</span></a></span><span class="refpurpose"> &#8212; 
164     adjust queue limits for stacked drivers
165 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-dma-pad.html"><span class="phrase">blk_queue_dma_pad</span></a></span><span class="refpurpose"> &#8212; 
166     set pad mask
167 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-update-dma-pad.html"><span class="phrase">blk_queue_update_dma_pad</span></a></span><span class="refpurpose"> &#8212; 
168     update pad mask
169 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-dma-drain.html"><span class="phrase">blk_queue_dma_drain</span></a></span><span class="refpurpose"> &#8212; 
170     Set up a drain buffer for excess dma.
171 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-segment-boundary.html"><span class="phrase">blk_queue_segment_boundary</span></a></span><span class="refpurpose"> &#8212; 
172     set boundary rules for segment merging
173 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-dma-alignment.html"><span class="phrase">blk_queue_dma_alignment</span></a></span><span class="refpurpose"> &#8212; 
174     set dma length and memory alignment
175 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-update-dma-alignment.html"><span class="phrase">blk_queue_update_dma_alignment</span></a></span><span class="refpurpose"> &#8212; 
176     update dma length and memory alignment
177 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-flush.html"><span class="phrase">blk_queue_flush</span></a></span><span class="refpurpose"> &#8212; 
178     configure queue's cache flush capability
179 </span></dt><dt><span class="refentrytitle"><a href="API-blk-execute-rq-nowait.html"><span class="phrase">blk_execute_rq_nowait</span></a></span><span class="refpurpose"> &#8212; 
180  insert a request into queue for execution
181 </span></dt><dt><span class="refentrytitle"><a href="API-blk-execute-rq.html"><span class="phrase">blk_execute_rq</span></a></span><span class="refpurpose"> &#8212; 
182     insert a request into queue for execution
183 </span></dt><dt><span class="refentrytitle"><a href="API-blkdev-issue-flush.html"><span class="phrase">blkdev_issue_flush</span></a></span><span class="refpurpose"> &#8212; 
184  queue a flush
185 </span></dt><dt><span class="refentrytitle"><a href="API-blkdev-issue-discard.html"><span class="phrase">blkdev_issue_discard</span></a></span><span class="refpurpose"> &#8212; 
186  queue a discard
187 </span></dt><dt><span class="refentrytitle"><a href="API-blkdev-issue-write-same.html"><span class="phrase">blkdev_issue_write_same</span></a></span><span class="refpurpose"> &#8212; 
188     queue a write same operation
189 </span></dt><dt><span class="refentrytitle"><a href="API-blkdev-issue-zeroout.html"><span class="phrase">blkdev_issue_zeroout</span></a></span><span class="refpurpose"> &#8212; 
190     zero-fill a block range
191 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-find-tag.html"><span class="phrase">blk_queue_find_tag</span></a></span><span class="refpurpose"> &#8212; 
192  find a request by its tag and queue
193 </span></dt><dt><span class="refentrytitle"><a href="API-blk-free-tags.html"><span class="phrase">blk_free_tags</span></a></span><span class="refpurpose"> &#8212; 
194     release a given set of tag maintenance info
195 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-free-tags.html"><span class="phrase">blk_queue_free_tags</span></a></span><span class="refpurpose"> &#8212; 
196     release tag maintenance info
197 </span></dt><dt><span class="refentrytitle"><a href="API-blk-init-tags.html"><span class="phrase">blk_init_tags</span></a></span><span class="refpurpose"> &#8212; 
198     initialize the tag info for an external tag map
199 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-init-tags.html"><span class="phrase">blk_queue_init_tags</span></a></span><span class="refpurpose"> &#8212; 
200     initialize the queue tag info
201 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-resize-tags.html"><span class="phrase">blk_queue_resize_tags</span></a></span><span class="refpurpose"> &#8212; 
202     change the queueing depth
203 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-end-tag.html"><span class="phrase">blk_queue_end_tag</span></a></span><span class="refpurpose"> &#8212; 
204     end tag operations for a request
205 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-start-tag.html"><span class="phrase">blk_queue_start_tag</span></a></span><span class="refpurpose"> &#8212; 
206     find a free tag and assign it
207 </span></dt><dt><span class="refentrytitle"><a href="API-blk-queue-invalidate-tags.html"><span class="phrase">blk_queue_invalidate_tags</span></a></span><span class="refpurpose"> &#8212; 
208     invalidate all pending tags
209 </span></dt><dt><span class="refentrytitle"><a href="API---blk-queue-free-tags.html"><span class="phrase">__blk_queue_free_tags</span></a></span><span class="refpurpose"> &#8212; 
210  release tag maintenance info
211 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-count-integrity-sg.html"><span class="phrase">blk_rq_count_integrity_sg</span></a></span><span class="refpurpose"> &#8212; 
212  Count number of integrity scatterlist elements
213 </span></dt><dt><span class="refentrytitle"><a href="API-blk-rq-map-integrity-sg.html"><span class="phrase">blk_rq_map_integrity_sg</span></a></span><span class="refpurpose"> &#8212; 
214     Map integrity metadata into a scatterlist
215 </span></dt><dt><span class="refentrytitle"><a href="API-blk-integrity-compare.html"><span class="phrase">blk_integrity_compare</span></a></span><span class="refpurpose"> &#8212; 
216     Compare integrity profile of two disks
217 </span></dt><dt><span class="refentrytitle"><a href="API-blk-integrity-register.html"><span class="phrase">blk_integrity_register</span></a></span><span class="refpurpose"> &#8212; 
218     Register a gendisk as being integrity-capable
219 </span></dt><dt><span class="refentrytitle"><a href="API-blk-integrity-unregister.html"><span class="phrase">blk_integrity_unregister</span></a></span><span class="refpurpose"> &#8212; 
220     Remove block integrity profile
221 </span></dt><dt><span class="refentrytitle"><a href="API-blk-trace-ioctl.html"><span class="phrase">blk_trace_ioctl</span></a></span><span class="refpurpose"> &#8212; 
222  handle the ioctls associated with tracing
223 </span></dt><dt><span class="refentrytitle"><a href="API-blk-trace-shutdown.html"><span class="phrase">blk_trace_shutdown</span></a></span><span class="refpurpose"> &#8212; 
224     stop and cleanup trace structures
225 </span></dt><dt><span class="refentrytitle"><a href="API-blk-add-trace-rq.html"><span class="phrase">blk_add_trace_rq</span></a></span><span class="refpurpose"> &#8212; 
226     Add a trace for a request oriented action
227 </span></dt><dt><span class="refentrytitle"><a href="API-blk-add-trace-bio.html"><span class="phrase">blk_add_trace_bio</span></a></span><span class="refpurpose"> &#8212; 
228     Add a trace for a bio oriented action
229 </span></dt><dt><span class="refentrytitle"><a href="API-blk-add-trace-bio-remap.html"><span class="phrase">blk_add_trace_bio_remap</span></a></span><span class="refpurpose"> &#8212; 
230     Add a trace for a bio-remap operation
231 </span></dt><dt><span class="refentrytitle"><a href="API-blk-add-trace-rq-remap.html"><span class="phrase">blk_add_trace_rq_remap</span></a></span><span class="refpurpose"> &#8212; 
232     Add a trace for a request-remap operation
233 </span></dt><dt><span class="refentrytitle"><a href="API-blk-mangle-minor.html"><span class="phrase">blk_mangle_minor</span></a></span><span class="refpurpose"> &#8212; 
234  scatter minor numbers apart
235 </span></dt><dt><span class="refentrytitle"><a href="API-blk-alloc-devt.html"><span class="phrase">blk_alloc_devt</span></a></span><span class="refpurpose"> &#8212; 
236     allocate a dev_t for a partition
237 </span></dt><dt><span class="refentrytitle"><a href="API-blk-free-devt.html"><span class="phrase">blk_free_devt</span></a></span><span class="refpurpose"> &#8212; 
238     free a dev_t
239 </span></dt><dt><span class="refentrytitle"><a href="API-disk-replace-part-tbl.html"><span class="phrase">disk_replace_part_tbl</span></a></span><span class="refpurpose"> &#8212; 
240     replace disk-&gt;part_tbl in RCU-safe way
241 </span></dt><dt><span class="refentrytitle"><a href="API-disk-expand-part-tbl.html"><span class="phrase">disk_expand_part_tbl</span></a></span><span class="refpurpose"> &#8212; 
242     expand disk-&gt;part_tbl
243 </span></dt><dt><span class="refentrytitle"><a href="API-disk-block-events.html"><span class="phrase">disk_block_events</span></a></span><span class="refpurpose"> &#8212; 
244     block and flush disk event checking
245 </span></dt><dt><span class="refentrytitle"><a href="API-disk-unblock-events.html"><span class="phrase">disk_unblock_events</span></a></span><span class="refpurpose"> &#8212; 
246     unblock disk event checking
247 </span></dt><dt><span class="refentrytitle"><a href="API-disk-flush-events.html"><span class="phrase">disk_flush_events</span></a></span><span class="refpurpose"> &#8212; 
248     schedule immediate event checking and flushing
249 </span></dt><dt><span class="refentrytitle"><a href="API-disk-clear-events.html"><span class="phrase">disk_clear_events</span></a></span><span class="refpurpose"> &#8212; 
250     synchronously check, clear and return pending events
251 </span></dt><dt><span class="refentrytitle"><a href="API-disk-get-part.html"><span class="phrase">disk_get_part</span></a></span><span class="refpurpose"> &#8212; 
252  get partition
253 </span></dt><dt><span class="refentrytitle"><a href="API-disk-part-iter-init.html"><span class="phrase">disk_part_iter_init</span></a></span><span class="refpurpose"> &#8212; 
254     initialize partition iterator
255 </span></dt><dt><span class="refentrytitle"><a href="API-disk-part-iter-next.html"><span class="phrase">disk_part_iter_next</span></a></span><span class="refpurpose"> &#8212; 
256     proceed iterator to the next partition and return it
257 </span></dt><dt><span class="refentrytitle"><a href="API-disk-part-iter-exit.html"><span class="phrase">disk_part_iter_exit</span></a></span><span class="refpurpose"> &#8212; 
258     finish up partition iteration
259 </span></dt><dt><span class="refentrytitle"><a href="API-disk-map-sector-rcu.html"><span class="phrase">disk_map_sector_rcu</span></a></span><span class="refpurpose"> &#8212; 
260     map sector to partition
261 </span></dt><dt><span class="refentrytitle"><a href="API-register-blkdev.html"><span class="phrase">register_blkdev</span></a></span><span class="refpurpose"> &#8212; 
262     register a new block device
263 </span></dt><dt><span class="refentrytitle"><a href="API-add-disk.html"><span class="phrase">add_disk</span></a></span><span class="refpurpose"> &#8212; 
264     add partitioning information to kernel list
265 </span></dt><dt><span class="refentrytitle"><a href="API-get-gendisk.html"><span class="phrase">get_gendisk</span></a></span><span class="refpurpose"> &#8212; 
266     get partitioning information for a given device
267 </span></dt><dt><span class="refentrytitle"><a href="API-bdget-disk.html"><span class="phrase">bdget_disk</span></a></span><span class="refpurpose"> &#8212; 
268     do <code class="function">bdget</code> by gendisk and partition number
269 </span></dt></dl></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-acct-process.html">Prev</a>&#160;</td><td width="20%" align="center">&#160;</td><td width="40%" align="right">&#160;<a accesskey="n" href="API-blk-get-backing-dev-info.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">acct_process</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">blk_get_backing_dev_info</span></td></tr></table></div></body></html>
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