<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>Chapter 14. Block Devices</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><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="re494.html" title="acct_process" /><link rel="next" href="re495.html" title="blk_get_backing_dev_info" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 14. Block Devices</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re494.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="re495.html">Next</a></td></tr></table><hr /></div><div class="chapter" title="Chapter 14. Block Devices"><div class="titlepage"><div><div><h2 class="title"><a id="blkdev"></a>Chapter 14. Block Devices</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="refentrytitle"><a href="re495.html"><span>blk_get_backing_dev_info</span></a></span><span class="refpurpose"> —
get the address of a queue's backing_dev_info
</span></dt><dt><span class="refentrytitle"><a href="re496.html"><span>blk_plug_device_unlocked</span></a></span><span class="refpurpose"> —
plug a device without queue lock held
</span></dt><dt><span class="refentrytitle"><a href="re497.html"><span>generic_unplug_device</span></a></span><span class="refpurpose"> —
fire a request queue
</span></dt><dt><span class="refentrytitle"><a href="re498.html"><span>blk_start_queue</span></a></span><span class="refpurpose"> —
restart a previously stopped queue
</span></dt><dt><span class="refentrytitle"><a href="re499.html"><span>blk_stop_queue</span></a></span><span class="refpurpose"> —
stop a queue
</span></dt><dt><span class="refentrytitle"><a href="re500.html"><span>blk_sync_queue</span></a></span><span class="refpurpose"> —
cancel any pending callbacks on a queue
</span></dt><dt><span class="refentrytitle"><a href="re501.html"><span>__blk_run_queue</span></a></span><span class="refpurpose"> —
run a single device queue
</span></dt><dt><span class="refentrytitle"><a href="re502.html"><span>blk_run_queue</span></a></span><span class="refpurpose"> —
run a single device queue
</span></dt><dt><span class="refentrytitle"><a href="re503.html"><span>blk_init_queue</span></a></span><span class="refpurpose"> —
prepare a request queue for use with a block device
</span></dt><dt><span class="refentrytitle"><a href="re504.html"><span>blk_make_request</span></a></span><span class="refpurpose"> —
given a bio, allocate a corresponding struct request.
</span></dt><dt><span class="refentrytitle"><a href="re505.html"><span>blk_requeue_request</span></a></span><span class="refpurpose"> —
put a request back on queue
</span></dt><dt><span class="refentrytitle"><a href="re506.html"><span>blk_insert_request</span></a></span><span class="refpurpose"> —
insert a special request into a request queue
</span></dt><dt><span class="refentrytitle"><a href="re507.html"><span>part_round_stats</span></a></span><span class="refpurpose"> —
Round off the performance stats on a struct disk_stats.
</span></dt><dt><span class="refentrytitle"><a href="re508.html"><span>blk_add_request_payload</span></a></span><span class="refpurpose"> —
add a payload to a request
</span></dt><dt><span class="refentrytitle"><a href="re509.html"><span>submit_bio</span></a></span><span class="refpurpose"> —
submit a bio to the block device layer for I/O
</span></dt><dt><span class="refentrytitle"><a href="re510.html"><span>blk_rq_check_limits</span></a></span><span class="refpurpose"> —
Helper function to check a request for the queue limit
</span></dt><dt><span class="refentrytitle"><a href="re511.html"><span>blk_insert_cloned_request</span></a></span><span class="refpurpose"> —
Helper for stacking drivers to submit a request
</span></dt><dt><span class="refentrytitle"><a href="re512.html"><span>blk_rq_err_bytes</span></a></span><span class="refpurpose"> —
determine number of bytes till the next failure boundary
</span></dt><dt><span class="refentrytitle"><a href="re513.html"><span>blk_peek_request</span></a></span><span class="refpurpose"> —
peek at the top of a request queue
</span></dt><dt><span class="refentrytitle"><a href="re514.html"><span>blk_start_request</span></a></span><span class="refpurpose"> —
start request processing on the driver
</span></dt><dt><span class="refentrytitle"><a href="re515.html"><span>blk_fetch_request</span></a></span><span class="refpurpose"> —
fetch a request from a request queue
</span></dt><dt><span class="refentrytitle"><a href="re516.html"><span>blk_update_request</span></a></span><span class="refpurpose"> —
Special helper function for request stacking drivers
</span></dt><dt><span class="refentrytitle"><a href="re517.html"><span>blk_unprep_request</span></a></span><span class="refpurpose"> —
unprepare a request
</span></dt><dt><span class="refentrytitle"><a href="re518.html"><span>blk_end_request</span></a></span><span class="refpurpose"> —
Helper function for drivers to complete the request.
</span></dt><dt><span class="refentrytitle"><a href="re519.html"><span>blk_end_request_all</span></a></span><span class="refpurpose"> —
Helper function for drives to finish the request.
</span></dt><dt><span class="refentrytitle"><a href="re520.html"><span>blk_end_request_cur</span></a></span><span class="refpurpose"> —
Helper function to finish the current request chunk.
</span></dt><dt><span class="refentrytitle"><a href="re521.html"><span>blk_end_request_err</span></a></span><span class="refpurpose"> —
Finish a request till the next failure boundary.
</span></dt><dt><span class="refentrytitle"><a href="re522.html"><span>__blk_end_request</span></a></span><span class="refpurpose"> —
Helper function for drivers to complete the request.
</span></dt><dt><span class="refentrytitle"><a href="re523.html"><span>__blk_end_request_all</span></a></span><span class="refpurpose"> —
Helper function for drives to finish the request.
</span></dt><dt><span class="refentrytitle"><a href="re524.html"><span>__blk_end_request_cur</span></a></span><span class="refpurpose"> —
Helper function to finish the current request chunk.
</span></dt><dt><span class="refentrytitle"><a href="re525.html"><span>__blk_end_request_err</span></a></span><span class="refpurpose"> —
Finish a request till the next failure boundary.
</span></dt><dt><span class="refentrytitle"><a href="re526.html"><span>blk_lld_busy</span></a></span><span class="refpurpose"> —
Check if underlying low-level drivers of a device are busy
</span></dt><dt><span class="refentrytitle"><a href="re527.html"><span>blk_rq_unprep_clone</span></a></span><span class="refpurpose"> —
Helper function to free all bios in a cloned request
</span></dt><dt><span class="refentrytitle"><a href="re528.html"><span>blk_rq_prep_clone</span></a></span><span class="refpurpose"> —
Helper function to setup clone request
</span></dt><dt><span class="refentrytitle"><a href="re529.html"><span>__generic_make_request</span></a></span><span class="refpurpose"> —
hand a buffer to its device driver for I/O
</span></dt><dt><span class="refentrytitle"><a href="re530.html"><span>blk_end_bidi_request</span></a></span><span class="refpurpose"> —
Complete a bidi request
</span></dt><dt><span class="refentrytitle"><a href="re531.html"><span>__blk_end_bidi_request</span></a></span><span class="refpurpose"> —
Complete a bidi request with queue lock held
</span></dt><dt><span class="refentrytitle"><a href="re532.html"><span>blk_rq_map_user</span></a></span><span class="refpurpose"> —
map user data to a request, for REQ_TYPE_BLOCK_PC usage
</span></dt><dt><span class="refentrytitle"><a href="re533.html"><span>blk_rq_map_user_iov</span></a></span><span class="refpurpose"> —
map user data to a request, for REQ_TYPE_BLOCK_PC usage
</span></dt><dt><span class="refentrytitle"><a href="re534.html"><span>blk_rq_unmap_user</span></a></span><span class="refpurpose"> —
unmap a request with user data
</span></dt><dt><span class="refentrytitle"><a href="re535.html"><span>blk_rq_map_kern</span></a></span><span class="refpurpose"> —
map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
</span></dt><dt><span class="refentrytitle"><a href="re536.html"><span>blk_release_queue</span></a></span><span class="refpurpose"> —
release a <span class="structname">struct request_queue</span> when it is no longer needed
</span></dt><dt><span class="refentrytitle"><a href="re537.html"><span>blk_queue_prep_rq</span></a></span><span class="refpurpose"> —
set a prepare_request function for queue
</span></dt><dt><span class="refentrytitle"><a href="re538.html"><span>blk_queue_unprep_rq</span></a></span><span class="refpurpose"> —
set an unprepare_request function for queue
</span></dt><dt><span class="refentrytitle"><a href="re539.html"><span>blk_queue_merge_bvec</span></a></span><span class="refpurpose"> —
set a merge_bvec function for queue
</span></dt><dt><span class="refentrytitle"><a href="re540.html"><span>blk_set_default_limits</span></a></span><span class="refpurpose"> —
reset limits to default values
</span></dt><dt><span class="refentrytitle"><a href="re541.html"><span>blk_queue_make_request</span></a></span><span class="refpurpose"> —
define an alternate make_request function for a device
</span></dt><dt><span class="refentrytitle"><a href="re542.html"><span>blk_queue_bounce_limit</span></a></span><span class="refpurpose"> —
set bounce buffer limit for queue
</span></dt><dt><span class="refentrytitle"><a href="re543.html"><span>blk_queue_max_hw_sectors</span></a></span><span class="refpurpose"> —
set max sectors for a request for this queue
</span></dt><dt><span class="refentrytitle"><a href="re544.html"><span>blk_queue_max_discard_sectors</span></a></span><span class="refpurpose"> —
set max sectors for a single discard
</span></dt><dt><span class="refentrytitle"><a href="re545.html"><span>blk_queue_max_segments</span></a></span><span class="refpurpose"> —
set max hw segments for a request for this queue
</span></dt><dt><span class="refentrytitle"><a href="re546.html"><span>blk_queue_max_segment_size</span></a></span><span class="refpurpose"> —
set max segment size for blk_rq_map_sg
</span></dt><dt><span class="refentrytitle"><a href="re547.html"><span>blk_queue_logical_block_size</span></a></span><span class="refpurpose"> —
set logical block size for the queue
</span></dt><dt><span class="refentrytitle"><a href="re548.html"><span>blk_queue_physical_block_size</span></a></span><span class="refpurpose"> —
set physical block size for the queue
</span></dt><dt><span class="refentrytitle"><a href="re549.html"><span>blk_queue_alignment_offset</span></a></span><span class="refpurpose"> —
set physical block alignment offset
</span></dt><dt><span class="refentrytitle"><a href="re550.html"><span>blk_limits_io_min</span></a></span><span class="refpurpose"> —
set minimum request size for a device
</span></dt><dt><span class="refentrytitle"><a href="re551.html"><span>blk_queue_io_min</span></a></span><span class="refpurpose"> —
set minimum request size for the queue
</span></dt><dt><span class="refentrytitle"><a href="re552.html"><span>blk_limits_io_opt</span></a></span><span class="refpurpose"> —
set optimal request size for a device
</span></dt><dt><span class="refentrytitle"><a href="re553.html"><span>blk_queue_io_opt</span></a></span><span class="refpurpose"> —
set optimal request size for the queue
</span></dt><dt><span class="refentrytitle"><a href="re554.html"><span>blk_queue_stack_limits</span></a></span><span class="refpurpose"> —
inherit underlying queue limits for stacked drivers
</span></dt><dt><span class="refentrytitle"><a href="re555.html"><span>blk_stack_limits</span></a></span><span class="refpurpose"> —
adjust queue_limits for stacked devices
</span></dt><dt><span class="refentrytitle"><a href="re556.html"><span>bdev_stack_limits</span></a></span><span class="refpurpose"> —
adjust queue limits for stacked drivers
</span></dt><dt><span class="refentrytitle"><a href="re557.html"><span>disk_stack_limits</span></a></span><span class="refpurpose"> —
adjust queue limits for stacked drivers
</span></dt><dt><span class="refentrytitle"><a href="re558.html"><span>blk_queue_dma_pad</span></a></span><span class="refpurpose"> —
set pad mask
</span></dt><dt><span class="refentrytitle"><a href="re559.html"><span>blk_queue_update_dma_pad</span></a></span><span class="refpurpose"> —
update pad mask
</span></dt><dt><span class="refentrytitle"><a href="re560.html"><span>blk_queue_dma_drain</span></a></span><span class="refpurpose"> —
Set up a drain buffer for excess dma.
</span></dt><dt><span class="refentrytitle"><a href="re561.html"><span>blk_queue_segment_boundary</span></a></span><span class="refpurpose"> —
set boundary rules for segment merging
</span></dt><dt><span class="refentrytitle"><a href="re562.html"><span>blk_queue_dma_alignment</span></a></span><span class="refpurpose"> —
set dma length and memory alignment
</span></dt><dt><span class="refentrytitle"><a href="re563.html"><span>blk_queue_update_dma_alignment</span></a></span><span class="refpurpose"> —
update dma length and memory alignment
</span></dt><dt><span class="refentrytitle"><a href="re564.html"><span>blk_execute_rq_nowait</span></a></span><span class="refpurpose"> —
insert a request into queue for execution
</span></dt><dt><span class="refentrytitle"><a href="re565.html"><span>blk_execute_rq</span></a></span><span class="refpurpose"> —
insert a request into queue for execution
</span></dt><dt><span class="refentrytitle"><a href="re566.html"><span>blk_queue_ordered</span></a></span><span class="refpurpose"> —
does this queue support ordered writes
</span></dt><dt><span class="refentrytitle"><a href="re567.html"><span>blkdev_issue_flush</span></a></span><span class="refpurpose"> —
queue a flush
</span></dt><dt><span class="refentrytitle"><a href="re568.html"><span>blkdev_issue_discard</span></a></span><span class="refpurpose"> —
queue a discard
</span></dt><dt><span class="refentrytitle"><a href="re569.html"><span>blk_queue_find_tag</span></a></span><span class="refpurpose"> —
find a request by its tag and queue
</span></dt><dt><span class="refentrytitle"><a href="re570.html"><span>blk_free_tags</span></a></span><span class="refpurpose"> —
release a given set of tag maintenance info
</span></dt><dt><span class="refentrytitle"><a href="re571.html"><span>blk_queue_free_tags</span></a></span><span class="refpurpose"> —
release tag maintenance info
</span></dt><dt><span class="refentrytitle"><a href="re572.html"><span>blk_init_tags</span></a></span><span class="refpurpose"> —
initialize the tag info for an external tag map
</span></dt><dt><span class="refentrytitle"><a href="re573.html"><span>blk_queue_init_tags</span></a></span><span class="refpurpose"> —
initialize the queue tag info
</span></dt><dt><span class="refentrytitle"><a href="re574.html"><span>blk_queue_resize_tags</span></a></span><span class="refpurpose"> —
change the queueing depth
</span></dt><dt><span class="refentrytitle"><a href="re575.html"><span>blk_queue_end_tag</span></a></span><span class="refpurpose"> —
end tag operations for a request
</span></dt><dt><span class="refentrytitle"><a href="re576.html"><span>blk_queue_start_tag</span></a></span><span class="refpurpose"> —
find a free tag and assign it
</span></dt><dt><span class="refentrytitle"><a href="re577.html"><span>blk_queue_invalidate_tags</span></a></span><span class="refpurpose"> —
invalidate all pending tags
</span></dt><dt><span class="refentrytitle"><a href="re578.html"><span>__blk_free_tags</span></a></span><span class="refpurpose"> —
release a given set of tag maintenance info
</span></dt><dt><span class="refentrytitle"><a href="re579.html"><span>__blk_queue_free_tags</span></a></span><span class="refpurpose"> —
release tag maintenance info
</span></dt><dt><span class="refentrytitle"><a href="re580.html"><span>blk_rq_count_integrity_sg</span></a></span><span class="refpurpose"> —
Count number of integrity scatterlist elements
</span></dt><dt><span class="refentrytitle"><a href="re581.html"><span>blk_rq_map_integrity_sg</span></a></span><span class="refpurpose"> —
Map integrity metadata into a scatterlist
</span></dt><dt><span class="refentrytitle"><a href="re582.html"><span>blk_integrity_compare</span></a></span><span class="refpurpose"> —
Compare integrity profile of two disks
</span></dt><dt><span class="refentrytitle"><a href="re583.html"><span>blk_integrity_register</span></a></span><span class="refpurpose"> —
Register a gendisk as being integrity-capable
</span></dt><dt><span class="refentrytitle"><a href="re584.html"><span>blk_integrity_unregister</span></a></span><span class="refpurpose"> —
Remove block integrity profile
</span></dt><dt><span class="refentrytitle"><a href="re585.html"><span>blk_trace_ioctl</span></a></span><span class="refpurpose"> —
handle the ioctls associated with tracing
</span></dt><dt><span class="refentrytitle"><a href="re586.html"><span>blk_trace_shutdown</span></a></span><span class="refpurpose"> —
stop and cleanup trace structures
</span></dt><dt><span class="refentrytitle"><a href="re587.html"><span>blk_add_trace_rq</span></a></span><span class="refpurpose"> —
Add a trace for a request oriented action
</span></dt><dt><span class="refentrytitle"><a href="re588.html"><span>blk_add_trace_bio</span></a></span><span class="refpurpose"> —
Add a trace for a bio oriented action
</span></dt><dt><span class="refentrytitle"><a href="re589.html"><span>blk_add_trace_remap</span></a></span><span class="refpurpose"> —
Add a trace for a remap operation
</span></dt><dt><span class="refentrytitle"><a href="re590.html"><span>blk_add_trace_rq_remap</span></a></span><span class="refpurpose"> —
Add a trace for a request-remap operation
</span></dt><dt><span class="refentrytitle"><a href="re591.html"><span>blk_mangle_minor</span></a></span><span class="refpurpose"> —
scatter minor numbers apart
</span></dt><dt><span class="refentrytitle"><a href="re592.html"><span>blk_alloc_devt</span></a></span><span class="refpurpose"> —
allocate a dev_t for a partition
</span></dt><dt><span class="refentrytitle"><a href="re593.html"><span>blk_free_devt</span></a></span><span class="refpurpose"> —
free a dev_t
</span></dt><dt><span class="refentrytitle"><a href="re594.html"><span>get_gendisk</span></a></span><span class="refpurpose"> —
get partitioning information for a given device
</span></dt><dt><span class="refentrytitle"><a href="re595.html"><span>disk_replace_part_tbl</span></a></span><span class="refpurpose"> —
replace disk->part_tbl in RCU-safe way
</span></dt><dt><span class="refentrytitle"><a href="re596.html"><span>disk_expand_part_tbl</span></a></span><span class="refpurpose"> —
expand disk->part_tbl
</span></dt><dt><span class="refentrytitle"><a href="re597.html"><span>disk_get_part</span></a></span><span class="refpurpose"> —
get partition
</span></dt><dt><span class="refentrytitle"><a href="re598.html"><span>disk_part_iter_init</span></a></span><span class="refpurpose"> —
initialize partition iterator
</span></dt><dt><span class="refentrytitle"><a href="re599.html"><span>disk_part_iter_next</span></a></span><span class="refpurpose"> —
proceed iterator to the next partition and return it
</span></dt><dt><span class="refentrytitle"><a href="re600.html"><span>disk_part_iter_exit</span></a></span><span class="refpurpose"> —
finish up partition iteration
</span></dt><dt><span class="refentrytitle"><a href="re601.html"><span>disk_map_sector_rcu</span></a></span><span class="refpurpose"> —
map sector to partition
</span></dt><dt><span class="refentrytitle"><a href="re602.html"><span>register_blkdev</span></a></span><span class="refpurpose"> —
register a new block device
</span></dt><dt><span class="refentrytitle"><a href="re603.html"><span>add_disk</span></a></span><span class="refpurpose"> —
add partitioning information to kernel list
</span></dt><dt><span class="refentrytitle"><a href="re604.html"><span>bdget_disk</span></a></span><span class="refpurpose"> —
do <code class="function">bdget</code> by gendisk and partition number
</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="re494.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="re495.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>acct_process</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>blk_get_backing_dev_info</span></td></tr></table></div></body></html>
