Based on kernel version 6.3.13
. Page generated on 2023-08-29 08:35 EST
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 | ============================ struct request documentation ============================ Jens Axboe <jens.axboe@oracle.com> 27/05/02 .. FIXME: No idea about what does mean - seems just some noise, so comment it 1.0 Index 2.0 Struct request members classification 2.1 struct request members explanation 3.0 2.0 Short explanation of request members ==================================== Classification flags: = ==================== D driver member B block layer member I I/O scheduler member = ==================== Unless an entry contains a D classification, a device driver must not access this member. Some members may contain D classifications, but should only be access through certain macros or functions (eg ->flags). <linux/blkdev.h> =============================== ======= ======================================= Member Flag Comment =============================== ======= ======================================= struct list_head queuelist BI Organization on various internal queues ``void *elevator_private`` I I/O scheduler private data unsigned char cmd[16] D Driver can use this for setting up a cdb before execution, see blk_queue_prep_rq unsigned long flags DBI Contains info about data direction, request type, etc. int rq_status D Request status bits kdev_t rq_dev DBI Target device int errors DB Error counts sector_t sector DBI Target location unsigned long hard_nr_sectors B Used to keep sector sane unsigned long nr_sectors DBI Total number of sectors in request unsigned long hard_nr_sectors B Used to keep nr_sectors sane unsigned short nr_phys_segments DB Number of physical scatter gather segments in a request unsigned short nr_hw_segments DB Number of hardware scatter gather segments in a request unsigned int current_nr_sectors DB Number of sectors in first segment of request unsigned int hard_cur_sectors B Used to keep current_nr_sectors sane int tag DB TCQ tag, if assigned ``void *special`` D Free to be used by driver ``char *buffer`` D Map of first segment, also see section on bouncing SECTION ``struct completion *waiting`` D Can be used by driver to get signalled on request completion ``struct bio *bio`` DBI First bio in request ``struct bio *biotail`` DBI Last bio in request ``struct request_queue *q`` DB Request queue this request belongs to ``struct request_list *rl`` B Request list this request came from =============================== ======= ======================================= |