mirror of
https://github.com/torvalds/linux
synced 2024-09-27 23:10:58 +00:00
Merge branch 'stable/for-jens-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-3.8/drivers
This commit is contained in:
Jens Axboe
commit
8d0ff3924b
|
|
@ -39,6 +39,7 @@
|
|||
#include <linux/list.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/freezer.h>
|
||||
#include <linux/bitmap.h>
|
||||
|
||||
#include <xen/events.h>
|
||||
#include <xen/page.h>
|
||||
|
|
@ -79,6 +80,7 @@ struct pending_req {
|
|||
unsigned short operation;
|
||||
int status;
|
||||
struct list_head free_list;
|
||||
DECLARE_BITMAP(unmap_seg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
|
||||
};
|
||||
|
||||
#define BLKBACK_INVALID_HANDLE (~0)
|
||||
|
|
@ -98,6 +100,36 @@ struct xen_blkbk {
|
|||
|
||||
static struct xen_blkbk *blkbk;
|
||||
|
||||
/*
|
||||
* Maximum number of grant pages that can be mapped in blkback.
|
||||
* BLKIF_MAX_SEGMENTS_PER_REQUEST * RING_SIZE is the maximum number of
|
||||
* pages that blkback will persistently map.
|
||||
* Currently, this is:
|
||||
* RING_SIZE = 32 (for all known ring types)
|
||||
* BLKIF_MAX_SEGMENTS_PER_REQUEST = 11
|
||||
* sizeof(struct persistent_gnt) = 48
|
||||
* So the maximum memory used to store the grants is:
|
||||
* 32 * 11 * 48 = 16896 bytes
|
||||
*/
|
||||
static inline unsigned int max_mapped_grant_pages(enum blkif_protocol protocol)
|
||||
{
|
||||
switch (protocol) {
|
||||
case BLKIF_PROTOCOL_NATIVE:
|
||||
return __CONST_RING_SIZE(blkif, PAGE_SIZE) *
|
||||
BLKIF_MAX_SEGMENTS_PER_REQUEST;
|
||||
case BLKIF_PROTOCOL_X86_32:
|
||||
return __CONST_RING_SIZE(blkif_x86_32, PAGE_SIZE) *
|
||||
BLKIF_MAX_SEGMENTS_PER_REQUEST;
|
||||
case BLKIF_PROTOCOL_X86_64:
|
||||
return __CONST_RING_SIZE(blkif_x86_64, PAGE_SIZE) *
|
||||
BLKIF_MAX_SEGMENTS_PER_REQUEST;
|
||||
default:
|
||||
BUG();
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Little helpful macro to figure out the index and virtual address of the
|
||||
* pending_pages[..]. For each 'pending_req' we have have up to
|
||||
|
|
@ -129,6 +161,57 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
|
|||
static void make_response(struct xen_blkif *blkif, u64 id,
|
||||
unsigned short op, int st);
|
||||
|
||||
#define foreach_grant(pos, rbtree, node) \
|
||||
for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node); \
|
||||
&(pos)->node != NULL; \
|
||||
(pos) = container_of(rb_next(&(pos)->node), typeof(*(pos)), node))
|
||||
|
||||
|
||||
static void add_persistent_gnt(struct rb_root *root,
|
||||
struct persistent_gnt *persistent_gnt)
|
||||
{
|
||||
struct rb_node **new = &(root->rb_node), *parent = NULL;
|
||||
struct persistent_gnt *this;
|
||||
|
||||
/* Figure out where to put new node */
|
||||
while (*new) {
|
||||
this = container_of(*new, struct persistent_gnt, node);
|
||||
|
||||
parent = *new;
|
||||
if (persistent_gnt->gnt < this->gnt)
|
||||
new = &((*new)->rb_left);
|
||||
else if (persistent_gnt->gnt > this->gnt)
|
||||
new = &((*new)->rb_right);
|
||||
else {
|
||||
pr_alert(DRV_PFX " trying to add a gref that's already in the tree\n");
|
||||
BUG();
|
||||
}
|
||||
}
|
||||
|
||||
/* Add new node and rebalance tree. */
|
||||
rb_link_node(&(persistent_gnt->node), parent, new);
|
||||
rb_insert_color(&(persistent_gnt->node), root);
|
||||
}
|
||||
|
||||
static struct persistent_gnt *get_persistent_gnt(struct rb_root *root,
|
||||
grant_ref_t gref)
|
||||
{
|
||||
struct persistent_gnt *data;
|
||||
struct rb_node *node = root->rb_node;
|
||||
|
||||
while (node) {
|
||||
data = container_of(node, struct persistent_gnt, node);
|
||||
|
||||
if (gref < data->gnt)
|
||||
node = node->rb_left;
|
||||
else if (gref > data->gnt)
|
||||
node = node->rb_right;
|
||||
else
|
||||
return data;
|
||||
}
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* Retrieve from the 'pending_reqs' a free pending_req structure to be used.
|
||||
*/
|
||||
|
|
@ -275,6 +358,11 @@ int xen_blkif_schedule(void *arg)
|
|||
{
|
||||
struct xen_blkif *blkif = arg;
|
||||
struct xen_vbd *vbd = &blkif->vbd;
|
||||
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
struct persistent_gnt *persistent_gnt;
|
||||
int ret = 0;
|
||||
int segs_to_unmap = 0;
|
||||
|
||||
xen_blkif_get(blkif);
|
||||
|
||||
|
|
@ -302,6 +390,36 @@ int xen_blkif_schedule(void *arg)
|
|||
print_stats(blkif);
|
||||
}
|
||||
|
||||
/* Free all persistent grant pages */
|
||||
if (!RB_EMPTY_ROOT(&blkif->persistent_gnts)) {
|
||||
foreach_grant(persistent_gnt, &blkif->persistent_gnts, node) {
|
||||
BUG_ON(persistent_gnt->handle ==
|
||||
BLKBACK_INVALID_HANDLE);
|
||||
gnttab_set_unmap_op(&unmap[segs_to_unmap],
|
||||
(unsigned long) pfn_to_kaddr(page_to_pfn(
|
||||
persistent_gnt->page)),
|
||||
GNTMAP_host_map,
|
||||
persistent_gnt->handle);
|
||||
|
||||
pages[segs_to_unmap] = persistent_gnt->page;
|
||||
rb_erase(&persistent_gnt->node,
|
||||
&blkif->persistent_gnts);
|
||||
kfree(persistent_gnt);
|
||||
blkif->persistent_gnt_c--;
|
||||
|
||||
if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||
|
||||
!rb_next(&persistent_gnt->node)) {
|
||||
ret = gnttab_unmap_refs(unmap, NULL, pages,
|
||||
segs_to_unmap);
|
||||
BUG_ON(ret);
|
||||
segs_to_unmap = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
BUG_ON(blkif->persistent_gnt_c != 0);
|
||||
BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts));
|
||||
|
||||
if (log_stats)
|
||||
print_stats(blkif);
|
||||
|
||||
|
|
@ -328,6 +446,8 @@ static void xen_blkbk_unmap(struct pending_req *req)
|
|||
int ret;
|
||||
|
||||
for (i = 0; i < req->nr_pages; i++) {
|
||||
if (!test_bit(i, req->unmap_seg))
|
||||
continue;
|
||||
handle = pending_handle(req, i);
|
||||
if (handle == BLKBACK_INVALID_HANDLE)
|
||||
continue;
|
||||
|
|
@ -344,12 +464,26 @@ static void xen_blkbk_unmap(struct pending_req *req)
|
|||
|
||||
static int xen_blkbk_map(struct blkif_request *req,
|
||||
struct pending_req *pending_req,
|
||||
struct seg_buf seg[])
|
||||
struct seg_buf seg[],
|
||||
struct page *pages[])
|
||||
{
|
||||
struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
int i;
|
||||
struct persistent_gnt *persistent_gnts[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
struct page *pages_to_gnt[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
struct persistent_gnt *persistent_gnt = NULL;
|
||||
struct xen_blkif *blkif = pending_req->blkif;
|
||||
phys_addr_t addr = 0;
|
||||
int i, j;
|
||||
bool new_map;
|
||||
int nseg = req->u.rw.nr_segments;
|
||||
int segs_to_map = 0;
|
||||
int ret = 0;
|
||||
int use_persistent_gnts;
|
||||
|
||||
use_persistent_gnts = (blkif->vbd.feature_gnt_persistent);
|
||||
|
||||
BUG_ON(blkif->persistent_gnt_c >
|
||||
max_mapped_grant_pages(pending_req->blkif->blk_protocol));
|
||||
|
||||
/*
|
||||
* Fill out preq.nr_sects with proper amount of sectors, and setup
|
||||
|
|
@ -359,36 +493,146 @@ static int xen_blkbk_map(struct blkif_request *req,
|
|||
for (i = 0; i < nseg; i++) {
|
||||
uint32_t flags;
|
||||
|
||||
flags = GNTMAP_host_map;
|
||||
if (pending_req->operation != BLKIF_OP_READ)
|
||||
flags |= GNTMAP_readonly;
|
||||
gnttab_set_map_op(&map[i], vaddr(pending_req, i), flags,
|
||||
req->u.rw.seg[i].gref,
|
||||
pending_req->blkif->domid);
|
||||
if (use_persistent_gnts)
|
||||
persistent_gnt = get_persistent_gnt(
|
||||
&blkif->persistent_gnts,
|
||||
req->u.rw.seg[i].gref);
|
||||
|
||||
if (persistent_gnt) {
|
||||
/*
|
||||
* We are using persistent grants and
|
||||
* the grant is already mapped
|
||||
*/
|
||||
new_map = false;
|
||||
} else if (use_persistent_gnts &&
|
||||
blkif->persistent_gnt_c <
|
||||
max_mapped_grant_pages(blkif->blk_protocol)) {
|
||||
/*
|
||||
* We are using persistent grants, the grant is
|
||||
* not mapped but we have room for it
|
||||
*/
|
||||
new_map = true;
|
||||
persistent_gnt = kmalloc(
|
||||
sizeof(struct persistent_gnt),
|
||||
GFP_KERNEL);
|
||||
if (!persistent_gnt)
|
||||
return -ENOMEM;
|
||||
persistent_gnt->page = alloc_page(GFP_KERNEL);
|
||||
if (!persistent_gnt->page) {
|
||||
kfree(persistent_gnt);
|
||||
return -ENOMEM;
|
||||
}
|
||||
persistent_gnt->gnt = req->u.rw.seg[i].gref;
|
||||
persistent_gnt->handle = BLKBACK_INVALID_HANDLE;
|
||||
|
||||
pages_to_gnt[segs_to_map] =
|
||||
persistent_gnt->page;
|
||||
addr = (unsigned long) pfn_to_kaddr(
|
||||
page_to_pfn(persistent_gnt->page));
|
||||
|
||||
add_persistent_gnt(&blkif->persistent_gnts,
|
||||
persistent_gnt);
|
||||
blkif->persistent_gnt_c++;
|
||||
pr_debug(DRV_PFX " grant %u added to the tree of persistent grants, using %u/%u\n",
|
||||
persistent_gnt->gnt, blkif->persistent_gnt_c,
|
||||
max_mapped_grant_pages(blkif->blk_protocol));
|
||||
} else {
|
||||
/*
|
||||
* We are either using persistent grants and
|
||||
* hit the maximum limit of grants mapped,
|
||||
* or we are not using persistent grants.
|
||||
*/
|
||||
if (use_persistent_gnts &&
|
||||
!blkif->vbd.overflow_max_grants) {
|
||||
blkif->vbd.overflow_max_grants = 1;
|
||||
pr_alert(DRV_PFX " domain %u, device %#x is using maximum number of persistent grants\n",
|
||||
blkif->domid, blkif->vbd.handle);
|
||||
}
|
||||
new_map = true;
|
||||
pages[i] = blkbk->pending_page(pending_req, i);
|
||||
addr = vaddr(pending_req, i);
|
||||
pages_to_gnt[segs_to_map] =
|
||||
blkbk->pending_page(pending_req, i);
|
||||
}
|
||||
|
||||
if (persistent_gnt) {
|
||||
pages[i] = persistent_gnt->page;
|
||||
persistent_gnts[i] = persistent_gnt;
|
||||
} else {
|
||||
persistent_gnts[i] = NULL;
|
||||
}
|
||||
|
||||
if (new_map) {
|
||||
flags = GNTMAP_host_map;
|
||||
if (!persistent_gnt &&
|
||||
(pending_req->operation != BLKIF_OP_READ))
|
||||
flags |= GNTMAP_readonly;
|
||||
gnttab_set_map_op(&map[segs_to_map++], addr,
|
||||
flags, req->u.rw.seg[i].gref,
|
||||
blkif->domid);
|
||||
}
|
||||
}
|
||||
|
||||
ret = gnttab_map_refs(map, NULL, &blkbk->pending_page(pending_req, 0), nseg);
|
||||
BUG_ON(ret);
|
||||
if (segs_to_map) {
|
||||
ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map);
|
||||
BUG_ON(ret);
|
||||
}
|
||||
|
||||
/*
|
||||
* Now swizzle the MFN in our domain with the MFN from the other domain
|
||||
* so that when we access vaddr(pending_req,i) it has the contents of
|
||||
* the page from the other domain.
|
||||
*/
|
||||
for (i = 0; i < nseg; i++) {
|
||||
if (unlikely(map[i].status != 0)) {
|
||||
pr_debug(DRV_PFX "invalid buffer -- could not remap it\n");
|
||||
map[i].handle = BLKBACK_INVALID_HANDLE;
|
||||
ret |= 1;
|
||||
bitmap_zero(pending_req->unmap_seg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
|
||||
for (i = 0, j = 0; i < nseg; i++) {
|
||||
if (!persistent_gnts[i] ||
|
||||
persistent_gnts[i]->handle == BLKBACK_INVALID_HANDLE) {
|
||||
/* This is a newly mapped grant */
|
||||
BUG_ON(j >= segs_to_map);
|
||||
if (unlikely(map[j].status != 0)) {
|
||||
pr_debug(DRV_PFX "invalid buffer -- could not remap it\n");
|
||||
map[j].handle = BLKBACK_INVALID_HANDLE;
|
||||
ret |= 1;
|
||||
if (persistent_gnts[i]) {
|
||||
rb_erase(&persistent_gnts[i]->node,
|
||||
&blkif->persistent_gnts);
|
||||
blkif->persistent_gnt_c--;
|
||||
kfree(persistent_gnts[i]);
|
||||
persistent_gnts[i] = NULL;
|
||||
}
|
||||
}
|
||||
}
|
||||
if (persistent_gnts[i]) {
|
||||
if (persistent_gnts[i]->handle ==
|
||||
BLKBACK_INVALID_HANDLE) {
|
||||
/*
|
||||
* If this is a new persistent grant
|
||||
* save the handler
|
||||
*/
|
||||
persistent_gnts[i]->handle = map[j].handle;
|
||||
persistent_gnts[i]->dev_bus_addr =
|
||||
map[j++].dev_bus_addr;
|
||||
}
|
||||
pending_handle(pending_req, i) =
|
||||
persistent_gnts[i]->handle;
|
||||
|
||||
pending_handle(pending_req, i) = map[i].handle;
|
||||
if (ret)
|
||||
continue;
|
||||
|
||||
if (ret)
|
||||
continue;
|
||||
seg[i].buf = persistent_gnts[i]->dev_bus_addr |
|
||||
(req->u.rw.seg[i].first_sect << 9);
|
||||
} else {
|
||||
pending_handle(pending_req, i) = map[j].handle;
|
||||
bitmap_set(pending_req->unmap_seg, i, 1);
|
||||
|
||||
seg[i].buf = map[i].dev_bus_addr |
|
||||
(req->u.rw.seg[i].first_sect << 9);
|
||||
if (ret) {
|
||||
j++;
|
||||
continue;
|
||||
}
|
||||
|
||||
seg[i].buf = map[j++].dev_bus_addr |
|
||||
(req->u.rw.seg[i].first_sect << 9);
|
||||
}
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
|
@ -591,6 +835,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
|
|||
int operation;
|
||||
struct blk_plug plug;
|
||||
bool drain = false;
|
||||
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
|
||||
switch (req->operation) {
|
||||
case BLKIF_OP_READ:
|
||||
|
|
@ -677,7 +922,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
|
|||
* the hypercall to unmap the grants - that is all done in
|
||||
* xen_blkbk_unmap.
|
||||
*/
|
||||
if (xen_blkbk_map(req, pending_req, seg))
|
||||
if (xen_blkbk_map(req, pending_req, seg, pages))
|
||||
goto fail_flush;
|
||||
|
||||
/*
|
||||
|
|
@ -689,7 +934,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
|
|||
for (i = 0; i < nseg; i++) {
|
||||
while ((bio == NULL) ||
|
||||
(bio_add_page(bio,
|
||||
blkbk->pending_page(pending_req, i),
|
||||
pages[i],
|
||||
seg[i].nsec << 9,
|
||||
seg[i].buf & ~PAGE_MASK) == 0)) {
|
||||
|
||||
|
|
|
|||
|
|
@ -34,6 +34,7 @@
|
|||
#include <linux/vmalloc.h>
|
||||
#include <linux/wait.h>
|
||||
#include <linux/io.h>
|
||||
#include <linux/rbtree.h>
|
||||
#include <asm/setup.h>
|
||||
#include <asm/pgalloc.h>
|
||||
#include <asm/hypervisor.h>
|
||||
|
|
@ -160,10 +161,22 @@ struct xen_vbd {
|
|||
sector_t size;
|
||||
bool flush_support;
|
||||
bool discard_secure;
|
||||
|
||||
unsigned int feature_gnt_persistent:1;
|
||||
unsigned int overflow_max_grants:1;
|
||||
};
|
||||
|
||||
struct backend_info;
|
||||
|
||||
|
||||
struct persistent_gnt {
|
||||
struct page *page;
|
||||
grant_ref_t gnt;
|
||||
grant_handle_t handle;
|
||||
uint64_t dev_bus_addr;
|
||||
struct rb_node node;
|
||||
};
|
||||
|
||||
struct xen_blkif {
|
||||
/* Unique identifier for this interface. */
|
||||
domid_t domid;
|
||||
|
|
@ -190,6 +203,10 @@ struct xen_blkif {
|
|||
struct task_struct *xenblkd;
|
||||
unsigned int waiting_reqs;
|
||||
|
||||
/* tree to store persistent grants */
|
||||
struct rb_root persistent_gnts;
|
||||
unsigned int persistent_gnt_c;
|
||||
|
||||
/* statistics */
|
||||
unsigned long st_print;
|
||||
int st_rd_req;
|
||||
|
|
|
|||
|
|
@ -118,6 +118,7 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)
|
|||
atomic_set(&blkif->drain, 0);
|
||||
blkif->st_print = jiffies;
|
||||
init_waitqueue_head(&blkif->waiting_to_free);
|
||||
blkif->persistent_gnts.rb_node = NULL;
|
||||
|
||||
return blkif;
|
||||
}
|
||||
|
|
@ -673,6 +674,13 @@ static void connect(struct backend_info *be)
|
|||
|
||||
xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support);
|
||||
|
||||
err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u", 1);
|
||||
if (err) {
|
||||
xenbus_dev_fatal(dev, err, "writing %s/feature-persistent",
|
||||
dev->nodename);
|
||||
goto abort;
|
||||
}
|
||||
|
||||
err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu",
|
||||
(unsigned long long)vbd_sz(&be->blkif->vbd));
|
||||
if (err) {
|
||||
|
|
@ -721,6 +729,7 @@ static int connect_ring(struct backend_info *be)
|
|||
struct xenbus_device *dev = be->dev;
|
||||
unsigned long ring_ref;
|
||||
unsigned int evtchn;
|
||||
unsigned int pers_grants;
|
||||
char protocol[64] = "";
|
||||
int err;
|
||||
|
||||
|
|
@ -750,8 +759,18 @@ static int connect_ring(struct backend_info *be)
|
|||
xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol);
|
||||
return -1;
|
||||
}
|
||||
pr_info(DRV_PFX "ring-ref %ld, event-channel %d, protocol %d (%s)\n",
|
||||
ring_ref, evtchn, be->blkif->blk_protocol, protocol);
|
||||
err = xenbus_gather(XBT_NIL, dev->otherend,
|
||||
"feature-persistent", "%u",
|
||||
&pers_grants, NULL);
|
||||
if (err)
|
||||
pers_grants = 0;
|
||||
|
||||
be->blkif->vbd.feature_gnt_persistent = pers_grants;
|
||||
be->blkif->vbd.overflow_max_grants = 0;
|
||||
|
||||
pr_info(DRV_PFX "ring-ref %ld, event-channel %d, protocol %d (%s) %s\n",
|
||||
ring_ref, evtchn, be->blkif->blk_protocol, protocol,
|
||||
pers_grants ? "persistent grants" : "");
|
||||
|
||||
/* Map the shared frame, irq etc. */
|
||||
err = xen_blkif_map(be->blkif, ring_ref, evtchn);
|
||||
|
|
|
|||
|
|
@ -44,6 +44,7 @@
|
|||
#include <linux/mutex.h>
|
||||
#include <linux/scatterlist.h>
|
||||
#include <linux/bitmap.h>
|
||||
#include <linux/llist.h>
|
||||
|
||||
#include <xen/xen.h>
|
||||
#include <xen/xenbus.h>
|
||||
|
|
@ -64,10 +65,17 @@ enum blkif_state {
|
|||
BLKIF_STATE_SUSPENDED,
|
||||
};
|
||||
|
||||
struct grant {
|
||||
grant_ref_t gref;
|
||||
unsigned long pfn;
|
||||
struct llist_node node;
|
||||
};
|
||||
|
||||
struct blk_shadow {
|
||||
struct blkif_request req;
|
||||
struct request *request;
|
||||
unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
struct grant *grants_used[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
||||
};
|
||||
|
||||
static DEFINE_MUTEX(blkfront_mutex);
|
||||
|
|
@ -97,6 +105,8 @@ struct blkfront_info
|
|||
struct work_struct work;
|
||||
struct gnttab_free_callback callback;
|
||||
struct blk_shadow shadow[BLK_RING_SIZE];
|
||||
struct llist_head persistent_gnts;
|
||||
unsigned int persistent_gnts_c;
|
||||
unsigned long shadow_free;
|
||||
unsigned int feature_flush;
|
||||
unsigned int flush_op;
|
||||
|
|
@ -104,6 +114,7 @@ struct blkfront_info
|
|||
unsigned int feature_secdiscard:1;
|
||||
unsigned int discard_granularity;
|
||||
unsigned int discard_alignment;
|
||||
unsigned int feature_persistent:1;
|
||||
int is_ready;
|
||||
};
|
||||
|
||||
|
|
@ -287,21 +298,36 @@ static int blkif_queue_request(struct request *req)
|
|||
unsigned long id;
|
||||
unsigned int fsect, lsect;
|
||||
int i, ref;
|
||||
|
||||
/*
|
||||
* Used to store if we are able to queue the request by just using
|
||||
* existing persistent grants, or if we have to get new grants,
|
||||
* as there are not sufficiently many free.
|
||||
*/
|
||||
bool new_persistent_gnts;
|
||||
grant_ref_t gref_head;
|
||||
struct page *granted_page;
|
||||
struct grant *gnt_list_entry = NULL;
|
||||
struct scatterlist *sg;
|
||||
|
||||
if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
|
||||
return 1;
|
||||
|
||||
if (gnttab_alloc_grant_references(
|
||||
BLKIF_MAX_SEGMENTS_PER_REQUEST, &gref_head) < 0) {
|
||||
gnttab_request_free_callback(
|
||||
&info->callback,
|
||||
blkif_restart_queue_callback,
|
||||
info,
|
||||
BLKIF_MAX_SEGMENTS_PER_REQUEST);
|
||||
return 1;
|
||||
}
|
||||
/* Check if we have enought grants to allocate a requests */
|
||||
if (info->persistent_gnts_c < BLKIF_MAX_SEGMENTS_PER_REQUEST) {
|
||||
new_persistent_gnts = 1;
|
||||
if (gnttab_alloc_grant_references(
|
||||
BLKIF_MAX_SEGMENTS_PER_REQUEST - info->persistent_gnts_c,
|
||||
&gref_head) < 0) {
|
||||
gnttab_request_free_callback(
|
||||
&info->callback,
|
||||
blkif_restart_queue_callback,
|
||||
info,
|
||||
BLKIF_MAX_SEGMENTS_PER_REQUEST);
|
||||
return 1;
|
||||
}
|
||||
} else
|
||||
new_persistent_gnts = 0;
|
||||
|
||||
/* Fill out a communications ring structure. */
|
||||
ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
|
||||
|
|
@ -341,18 +367,73 @@ static int blkif_queue_request(struct request *req)
|
|||
BLKIF_MAX_SEGMENTS_PER_REQUEST);
|
||||
|
||||
for_each_sg(info->sg, sg, ring_req->u.rw.nr_segments, i) {
|
||||
buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg)));
|
||||
fsect = sg->offset >> 9;
|
||||
lsect = fsect + (sg->length >> 9) - 1;
|
||||
/* install a grant reference. */
|
||||
ref = gnttab_claim_grant_reference(&gref_head);
|
||||
BUG_ON(ref == -ENOSPC);
|
||||
|
||||
gnttab_grant_foreign_access_ref(
|
||||
ref,
|
||||
if (info->persistent_gnts_c) {
|
||||
BUG_ON(llist_empty(&info->persistent_gnts));
|
||||
gnt_list_entry = llist_entry(
|
||||
llist_del_first(&info->persistent_gnts),
|
||||
struct grant, node);
|
||||
|
||||
ref = gnt_list_entry->gref;
|
||||
buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn);
|
||||
info->persistent_gnts_c--;
|
||||
} else {
|
||||
ref = gnttab_claim_grant_reference(&gref_head);
|
||||
BUG_ON(ref == -ENOSPC);
|
||||
|
||||
gnt_list_entry =
|
||||
kmalloc(sizeof(struct grant),
|
||||
GFP_ATOMIC);
|
||||
if (!gnt_list_entry)
|
||||
return -ENOMEM;
|
||||
|
||||
granted_page = alloc_page(GFP_ATOMIC);
|
||||
if (!granted_page) {
|
||||
kfree(gnt_list_entry);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
gnt_list_entry->pfn =
|
||||
page_to_pfn(granted_page);
|
||||
gnt_list_entry->gref = ref;
|
||||
|
||||
buffer_mfn = pfn_to_mfn(page_to_pfn(
|
||||
granted_page));
|
||||
gnttab_grant_foreign_access_ref(ref,
|
||||
info->xbdev->otherend_id,
|
||||
buffer_mfn,
|
||||
rq_data_dir(req));
|
||||
buffer_mfn, 0);
|
||||
}
|
||||
|
||||
info->shadow[id].grants_used[i] = gnt_list_entry;
|
||||
|
||||
if (rq_data_dir(req)) {
|
||||
char *bvec_data;
|
||||
void *shared_data;
|
||||
|
||||
BUG_ON(sg->offset + sg->length > PAGE_SIZE);
|
||||
|
||||
shared_data = kmap_atomic(
|
||||
pfn_to_page(gnt_list_entry->pfn));
|
||||
bvec_data = kmap_atomic(sg_page(sg));
|
||||
|
||||
/*
|
||||
* this does not wipe data stored outside the
|
||||
* range sg->offset..sg->offset+sg->length.
|
||||
* Therefore, blkback *could* see data from
|
||||
* previous requests. This is OK as long as
|
||||
* persistent grants are shared with just one
|
||||
* domain. It may need refactoring if this
|
||||
* changes
|
||||
*/
|
||||
memcpy(shared_data + sg->offset,
|
||||
bvec_data + sg->offset,
|
||||
sg->length);
|
||||
|
||||
kunmap_atomic(bvec_data);
|
||||
kunmap_atomic(shared_data);
|
||||
}
|
||||
|
||||
info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
|
||||
ring_req->u.rw.seg[i] =
|
||||
|
|
@ -368,7 +449,8 @@ static int blkif_queue_request(struct request *req)
|
|||
/* Keep a private copy so we can reissue requests when recovering. */
|
||||
info->shadow[id].req = *ring_req;
|
||||
|
||||
gnttab_free_grant_references(gref_head);
|
||||
if (new_persistent_gnts)
|
||||
gnttab_free_grant_references(gref_head);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -480,12 +562,13 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
|
|||
static void xlvbd_flush(struct blkfront_info *info)
|
||||
{
|
||||
blk_queue_flush(info->rq, info->feature_flush);
|
||||
printk(KERN_INFO "blkfront: %s: %s: %s\n",
|
||||
printk(KERN_INFO "blkfront: %s: %s: %s %s\n",
|
||||
info->gd->disk_name,
|
||||
info->flush_op == BLKIF_OP_WRITE_BARRIER ?
|
||||
"barrier" : (info->flush_op == BLKIF_OP_FLUSH_DISKCACHE ?
|
||||
"flush diskcache" : "barrier or flush"),
|
||||
info->feature_flush ? "enabled" : "disabled");
|
||||
info->feature_flush ? "enabled" : "disabled",
|
||||
info->feature_persistent ? "using persistent grants" : "");
|
||||
}
|
||||
|
||||
static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset)
|
||||
|
|
@ -707,6 +790,9 @@ static void blkif_restart_queue(struct work_struct *work)
|
|||
|
||||
static void blkif_free(struct blkfront_info *info, int suspend)
|
||||
{
|
||||
struct llist_node *all_gnts;
|
||||
struct grant *persistent_gnt;
|
||||
|
||||
/* Prevent new requests being issued until we fix things up. */
|
||||
spin_lock_irq(&info->io_lock);
|
||||
info->connected = suspend ?
|
||||
|
|
@ -714,6 +800,17 @@ static void blkif_free(struct blkfront_info *info, int suspend)
|
|||
/* No more blkif_request(). */
|
||||
if (info->rq)
|
||||
blk_stop_queue(info->rq);
|
||||
|
||||
/* Remove all persistent grants */
|
||||
if (info->persistent_gnts_c) {
|
||||
all_gnts = llist_del_all(&info->persistent_gnts);
|
||||
llist_for_each_entry(persistent_gnt, all_gnts, node) {
|
||||
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
|
||||
kfree(persistent_gnt);
|
||||
}
|
||||
info->persistent_gnts_c = 0;
|
||||
}
|
||||
|
||||
/* No more gnttab callback work. */
|
||||
gnttab_cancel_free_callback(&info->callback);
|
||||
spin_unlock_irq(&info->io_lock);
|
||||
|
|
@ -734,13 +831,43 @@ static void blkif_free(struct blkfront_info *info, int suspend)
|
|||
|
||||
}
|
||||
|
||||
static void blkif_completion(struct blk_shadow *s)
|
||||
static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
|
||||
struct blkif_response *bret)
|
||||
{
|
||||
int i;
|
||||
/* Do not let BLKIF_OP_DISCARD as nr_segment is in the same place
|
||||
* flag. */
|
||||
for (i = 0; i < s->req.u.rw.nr_segments; i++)
|
||||
gnttab_end_foreign_access(s->req.u.rw.seg[i].gref, 0, 0UL);
|
||||
struct bio_vec *bvec;
|
||||
struct req_iterator iter;
|
||||
unsigned long flags;
|
||||
char *bvec_data;
|
||||
void *shared_data;
|
||||
unsigned int offset = 0;
|
||||
|
||||
if (bret->operation == BLKIF_OP_READ) {
|
||||
/*
|
||||
* Copy the data received from the backend into the bvec.
|
||||
* Since bv_offset can be different than 0, and bv_len different
|
||||
* than PAGE_SIZE, we have to keep track of the current offset,
|
||||
* to be sure we are copying the data from the right shared page.
|
||||
*/
|
||||
rq_for_each_segment(bvec, s->request, iter) {
|
||||
BUG_ON((bvec->bv_offset + bvec->bv_len) > PAGE_SIZE);
|
||||
i = offset >> PAGE_SHIFT;
|
||||
BUG_ON(i >= s->req.u.rw.nr_segments);
|
||||
shared_data = kmap_atomic(
|
||||
pfn_to_page(s->grants_used[i]->pfn));
|
||||
bvec_data = bvec_kmap_irq(bvec, &flags);
|
||||
memcpy(bvec_data, shared_data + bvec->bv_offset,
|
||||
bvec->bv_len);
|
||||
bvec_kunmap_irq(bvec_data, &flags);
|
||||
kunmap_atomic(shared_data);
|
||||
offset += bvec->bv_len;
|
||||
}
|
||||
}
|
||||
/* Add the persistent grant into the list of free grants */
|
||||
for (i = 0; i < s->req.u.rw.nr_segments; i++) {
|
||||
llist_add(&s->grants_used[i]->node, &info->persistent_gnts);
|
||||
info->persistent_gnts_c++;
|
||||
}
|
||||
}
|
||||
|
||||
static irqreturn_t blkif_interrupt(int irq, void *dev_id)
|
||||
|
|
@ -783,7 +910,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
|
|||
req = info->shadow[id].request;
|
||||
|
||||
if (bret->operation != BLKIF_OP_DISCARD)
|
||||
blkif_completion(&info->shadow[id]);
|
||||
blkif_completion(&info->shadow[id], info, bret);
|
||||
|
||||
if (add_id_to_freelist(info, id)) {
|
||||
WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n",
|
||||
|
|
@ -942,6 +1069,11 @@ static int talk_to_blkback(struct xenbus_device *dev,
|
|||
message = "writing protocol";
|
||||
goto abort_transaction;
|
||||
}
|
||||
err = xenbus_printf(xbt, dev->nodename,
|
||||
"feature-persistent", "%u", 1);
|
||||
if (err)
|
||||
dev_warn(&dev->dev,
|
||||
"writing persistent grants feature to xenbus");
|
||||
|
||||
err = xenbus_transaction_end(xbt, 0);
|
||||
if (err) {
|
||||
|
|
@ -1029,6 +1161,8 @@ static int blkfront_probe(struct xenbus_device *dev,
|
|||
spin_lock_init(&info->io_lock);
|
||||
info->xbdev = dev;
|
||||
info->vdevice = vdevice;
|
||||
init_llist_head(&info->persistent_gnts);
|
||||
info->persistent_gnts_c = 0;
|
||||
info->connected = BLKIF_STATE_DISCONNECTED;
|
||||
INIT_WORK(&info->work, blkif_restart_queue);
|
||||
|
||||
|
|
@ -1093,7 +1227,7 @@ static int blkif_recover(struct blkfront_info *info)
|
|||
req->u.rw.seg[j].gref,
|
||||
info->xbdev->otherend_id,
|
||||
pfn_to_mfn(info->shadow[req->u.rw.id].frame[j]),
|
||||
rq_data_dir(info->shadow[req->u.rw.id].request));
|
||||
0);
|
||||
}
|
||||
info->shadow[req->u.rw.id].req = *req;
|
||||
|
||||
|
|
@ -1225,7 +1359,7 @@ static void blkfront_connect(struct blkfront_info *info)
|
|||
unsigned long sector_size;
|
||||
unsigned int binfo;
|
||||
int err;
|
||||
int barrier, flush, discard;
|
||||
int barrier, flush, discard, persistent;
|
||||
|
||||
switch (info->connected) {
|
||||
case BLKIF_STATE_CONNECTED:
|
||||
|
|
@ -1303,6 +1437,14 @@ static void blkfront_connect(struct blkfront_info *info)
|
|||
if (!err && discard)
|
||||
blkfront_setup_discard(info);
|
||||
|
||||
err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
|
||||
"feature-persistent", "%u", &persistent,
|
||||
NULL);
|
||||
if (err)
|
||||
info->feature_persistent = 0;
|
||||
else
|
||||
info->feature_persistent = persistent;
|
||||
|
||||
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
|
||||
if (err) {
|
||||
xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s",
|
||||
|
|
|
|||
Loading…
Reference in a new issue