Sign Up
Log In
Log In
or
Sign Up
Places
All Projects
Status Monitor
Collapse sidebar
home:steve-beattie
kernel
linux-2.6-scsi-fix-shared-tag-maps.patch
Overview
Repositories
Revisions
Requests
Users
Attributes
Meta
File linux-2.6-scsi-fix-shared-tag-maps.patch of Package kernel
Date: Mon, 9 Oct 2006 03:03:32 -0400 From: Jeff Garzik <jgarzik@redhat.com> Subject: [RHEL5 PATCH 1/2] block & scsi: fix shared tag maps Update shared TCQ map support, which was always fundamentally incomplete and broken. From upstream. The only publicly visible change is an added struct member to Scsi_Host. Required for patch #2, which addresses BZ#209179. block/ll_rw_blk.c | 122 +++++++++++++++++++++++++++++++++++++---------- drivers/scsi/hosts.c | 3 + include/linux/blkdev.h | 2 include/scsi/scsi_host.h | 7 ++ include/scsi/scsi_tcq.h | 15 +++++ 5 files changed, 123 insertions(+), 26 deletions(-) diff -urN linux-2.6.18.x86_64/block/ll_rw_blk.c linux-2.6.18.x86_64.stex1/block/ll_rw_blk.c --- linux-2.6.18.x86_64/block/ll_rw_blk.c 2006-09-19 23:42:06.000000000 -0400 +++ linux-2.6.18.x86_64.stex1/block/ll_rw_blk.c 2006-10-08 21:28:47.000000000 -0400 @@ -848,21 +848,18 @@ EXPORT_SYMBOL(blk_queue_find_tag); /** - * __blk_queue_free_tags - release tag maintenance info - * @q: the request queue for the device + * __blk_free_tags - release a given set of tag maintenance info + * @bqt: the tag map to free * - * Notes: - * blk_cleanup_queue() will take care of calling this function, if tagging - * has been used. So there's no need to call this directly. - **/ -static void __blk_queue_free_tags(request_queue_t *q) + * Tries to free the specified @bqt@. Returns true if it was + * actually freed and false if there are still references using it + */ +static int __blk_free_tags(struct blk_queue_tag *bqt) { - struct blk_queue_tag *bqt = q->queue_tags; + int retval; - if (!bqt) - return; - - if (atomic_dec_and_test(&bqt->refcnt)) { + retval = atomic_dec_and_test(&bqt->refcnt); + if (retval) { BUG_ON(bqt->busy); BUG_ON(!list_empty(&bqt->busy_list)); @@ -873,12 +870,49 @@ bqt->tag_map = NULL; kfree(bqt); + } + return retval; +} + +/** + * __blk_queue_free_tags - release tag maintenance info + * @q: the request queue for the device + * + * Notes: + * blk_cleanup_queue() will take care of calling this function, if tagging + * has been used. So there's no need to call this directly. + **/ +static void __blk_queue_free_tags(request_queue_t *q) +{ + struct blk_queue_tag *bqt = q->queue_tags; + + if (!bqt) + return; + + __blk_free_tags(bqt); + q->queue_tags = NULL; q->queue_flags &= ~(1 << QUEUE_FLAG_QUEUED); } + +/** + * blk_free_tags - release a given set of tag maintenance info + * @bqt: the tag map to free + * + * For externally managed @bqt@ frees the map. Callers of this + * function must guarantee to have released all the queues that + * might have been using this tag map. + */ +void blk_free_tags(struct blk_queue_tag *bqt) +{ + if (unlikely(!__blk_free_tags(bqt))) + BUG(); +} +EXPORT_SYMBOL(blk_free_tags); + /** * blk_queue_free_tags - release tag maintenance info * @q: the request queue for the device @@ -901,7 +935,7 @@ unsigned long *tag_map; int nr_ulongs; - if (depth > q->nr_requests * 2) { + if (q && depth > q->nr_requests * 2) { depth = q->nr_requests * 2; printk(KERN_ERR "%s: adjusted depth to %d\n", __FUNCTION__, depth); @@ -927,6 +961,38 @@ return -ENOMEM; } +static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q, + int depth) +{ + struct blk_queue_tag *tags; + + tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC); + if (!tags) + goto fail; + + if (init_tag_map(q, tags, depth)) + goto fail; + + INIT_LIST_HEAD(&tags->busy_list); + tags->busy = 0; + atomic_set(&tags->refcnt, 1); + return tags; +fail: + kfree(tags); + return NULL; +} + +/** + * blk_init_tags - initialize the tag info for an external tag map + * @depth: the maximum queue depth supported + * @tags: the tag to use + **/ +struct blk_queue_tag *blk_init_tags(int depth) +{ + return __blk_queue_init_tags(NULL, depth); +} +EXPORT_SYMBOL(blk_init_tags); + /** * blk_queue_init_tags - initialize the queue tag info * @q: the request queue for the device @@ -941,16 +1007,10 @@ BUG_ON(tags && q->queue_tags && tags != q->queue_tags); if (!tags && !q->queue_tags) { - tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC); - if (!tags) - goto fail; + tags = __blk_queue_init_tags(q, depth); - if (init_tag_map(q, tags, depth)) + if (!tags) goto fail; - - INIT_LIST_HEAD(&tags->busy_list); - tags->busy = 0; - atomic_set(&tags->refcnt, 1); } else if (q->queue_tags) { if ((rc = blk_queue_resize_tags(q, depth))) return rc; @@ -1002,6 +1062,13 @@ } /* + * Currently cannot replace a shared tag map with a new + * one, so error out if this is the case + */ + if (atomic_read(&bqt->refcnt) != 1) + return -EBUSY; + + /* * save the old state info, so we can copy it back */ tag_index = bqt->tag_index; @@ -1101,11 +1168,16 @@ BUG(); } - tag = find_first_zero_bit(bqt->tag_map, bqt->max_depth); - if (tag >= bqt->max_depth) - return 1; + /* + * Protect against shared tag maps, as we may not have exclusive + * access to the tag map. + */ + do { + tag = find_first_zero_bit(bqt->tag_map, bqt->max_depth); + if (tag >= bqt->max_depth) + return 1; - __set_bit(tag, bqt->tag_map); + } while (test_and_set_bit(tag, bqt->tag_map)); rq->flags |= REQ_QUEUED; rq->tag = tag; diff -urN linux-2.6.18.x86_64/drivers/scsi/hosts.c linux-2.6.18.x86_64.stex1/drivers/scsi/hosts.c --- linux-2.6.18.x86_64/drivers/scsi/hosts.c 2006-09-19 23:42:06.000000000 -0400 +++ linux-2.6.18.x86_64.stex1/drivers/scsi/hosts.c 2006-10-08 21:28:45.000000000 -0400 @@ -265,6 +265,9 @@ destroy_workqueue(shost->work_q); scsi_destroy_command_freelist(shost); + if (shost->bqt) + blk_free_tags(shost->bqt); + kfree(shost->shost_data); if (parent) diff -urN linux-2.6.18.x86_64/include/linux/blkdev.h linux-2.6.18.x86_64.stex1/include/linux/blkdev.h --- linux-2.6.18.x86_64/include/linux/blkdev.h 2006-09-19 23:42:06.000000000 -0400 +++ linux-2.6.18.x86_64.stex1/include/linux/blkdev.h 2006-10-08 21:28:46.000000000 -0400 @@ -746,6 +746,8 @@ extern int blk_queue_resize_tags(request_queue_t *, int); extern void blk_queue_invalidate_tags(request_queue_t *); extern long blk_congestion_wait(int rw, long timeout); +extern struct blk_queue_tag *blk_init_tags(int); +extern void blk_free_tags(struct blk_queue_tag *); extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); extern int blkdev_issue_flush(struct block_device *, sector_t *); diff -urN linux-2.6.18.x86_64/include/scsi/scsi_host.h linux-2.6.18.x86_64.stex1/include/scsi/scsi_host.h --- linux-2.6.18.x86_64/include/scsi/scsi_host.h 2006-09-19 23:42:06.000000000 -0400 +++ linux-2.6.18.x86_64.stex1/include/scsi/scsi_host.h 2006-10-08 21:28:45.000000000 -0400 @@ -16,6 +16,7 @@ struct Scsi_Host; struct scsi_host_cmd_pool; struct scsi_transport_template; +struct blk_queue_tags; /* @@ -466,6 +467,12 @@ struct scsi_transport_template *transportt; /* + * area to keep a shared tag map (if needed, will be + * NULL if not) + */ + struct blk_queue_tag *bqt; + + /* * The following two fields are protected with host_lock; * however, eh routines can safely access during eh processing * without acquiring the lock. diff -urN linux-2.6.18.x86_64/include/scsi/scsi_tcq.h linux-2.6.18.x86_64.stex1/include/scsi/scsi_tcq.h --- linux-2.6.18.x86_64/include/scsi/scsi_tcq.h 2006-09-19 23:42:06.000000000 -0400 +++ linux-2.6.18.x86_64.stex1/include/scsi/scsi_tcq.h 2006-10-08 21:28:48.000000000 -0400 @@ -4,6 +4,7 @@ #include <linux/blkdev.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_device.h> +#include <scsi/scsi_host.h> #define MSG_SIMPLE_TAG 0x20 @@ -66,7 +67,8 @@ return; if (!blk_queue_tagged(sdev->request_queue)) - blk_queue_init_tags(sdev->request_queue, depth, NULL); + blk_queue_init_tags(sdev->request_queue, depth, + sdev->host->bqt); scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth); } @@ -131,4 +133,15 @@ return sdev->current_cmnd; } +/** + * scsi_init_shared_tag_map - create a shared tag map + * @shost: the host to share the tag map among all devices + * @depth: the total depth of the map + */ +static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth) +{ + shost->bqt = blk_init_tags(depth); + return shost->bqt ? 0 : -ENOMEM; +} + #endif /* _SCSI_SCSI_TCQ_H */
Locations
Projects
Search
Status Monitor
Help
OpenBuildService.org
Documentation
API Documentation
Code of Conduct
Contact
Support
@OBShq
Terms
openSUSE Build Service is sponsored by
The Open Build Service is an
openSUSE project
.
Sign Up
Log In
Places
Places
All Projects
Status Monitor
