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author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/block/request.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/block/request.txt')
-rw-r--r-- | kernel/Documentation/block/request.txt | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/kernel/Documentation/block/request.txt b/kernel/Documentation/block/request.txt new file mode 100644 index 000000000..754e104ed --- /dev/null +++ b/kernel/Documentation/block/request.txt @@ -0,0 +1,88 @@ + +struct request documentation + +Jens Axboe <jens.axboe@oracle.com> 27/05/02 + +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> + +2.1 +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 |