Module Name: src
Committed By: jdolecek
Date: Mon Apr 20 16:12:28 UTC 2020
Modified Files:
src/sys/arch/xen/xen: xbdback_xenbus.c
Log Message:
remove I/O defragmentation logic, pass requests straight to the
underlying block device without trying to coalesce them
it seems rarely useful, and it makes the handling logic unnecessarily complex -
ultimately it's the DomU operating system responsibility to issue optimal I/O
might also help with the ZFS problem reported on port-xen, and will surely
simplify eventual indirect segment support
To generate a diff of this commit:
cvs rdiff -u -r1.82 -r1.83 src/sys/arch/xen/xen/xbdback_xenbus.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xbdback_xenbus.c
diff -u src/sys/arch/xen/xen/xbdback_xenbus.c:1.82 src/sys/arch/xen/xen/xbdback_xenbus.c:1.83
--- src/sys/arch/xen/xen/xbdback_xenbus.c:1.82 Mon Apr 20 14:11:04 2020
+++ src/sys/arch/xen/xen/xbdback_xenbus.c Mon Apr 20 16:12:28 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: xbdback_xenbus.c,v 1.82 2020/04/20 14:11:04 jdolecek Exp $ */
+/* $NetBSD: xbdback_xenbus.c,v 1.83 2020/04/20 16:12:28 jdolecek Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.82 2020/04/20 14:11:04 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.83 2020/04/20 16:12:28 jdolecek Exp $");
#include <sys/atomic.h>
#include <sys/buf.h>
@@ -74,9 +74,7 @@ __KERNEL_RCSID(0, "$NetBSD: xbdback_xenb
/* Need to alloc one extra page to account for possible mapping offset */
#define VBD_VA_SIZE (MAXPHYS + PAGE_SIZE)
-struct xbdback_request;
struct xbdback_io;
-struct xbdback_fragment;
struct xbdback_instance;
/*
@@ -98,8 +96,8 @@ typedef enum {WAITING, RUN, DISCONNECTIN
* callback), the return value of a continuation can be set to NULL. In that
* case, the thread will go back to sleeping and wait for the proper
* condition before it starts processing requests again from where it left.
- * Continuation state is "stored" in the xbdback instance (xbdi_cont and
- * xbdi_cont_aux), and should only be manipulated by the instance thread.
+ * Continuation state is "stored" in the xbdback instance (xbdi_cont),
+ * and should only be manipulated by the instance thread.
*
* As xbdback(4) has to handle different sort of asynchronous events (Xen
* event channels, biointr() soft interrupts, xenbus commands), the xbdi_lock
@@ -109,36 +107,23 @@ typedef enum {WAITING, RUN, DISCONNECTIN
* Here's how the call graph is supposed to be for a single I/O:
*
* xbdback_co_main()
- * |
- * | --> xbdback_co_cache_doflush() or NULL
- * | |
- * | - xbdback_co_cache_flush2() <- xbdback_co_do_io() <-
- * | | |
- * | |-> xbdback_co_cache_flush() -> xbdback_co_map_io()-
+ * | --> xbdback_co_cache_flush()
+ * | | |
+ * | | -> xbdback_co_cache_doflush() or NULL
+ * | | |
+ * | | -> xbdback_co_do_io()
* xbdback_co_main_loop()-|
- * | |-> xbdback_co_main_done() ---> xbdback_co_map_io()-
- * | | |
- * | -- xbdback_co_main_done2() <-- xbdback_co_do_io() <-
+ * | |-> xbdback_co_main_done2() or NULL
* | |
- * | --> xbdback_co_main() or NULL
+ * | --> xbdback_co_main_incr() -> xbdback_co_main_loop()
* |
* xbdback_co_io() -> xbdback_co_main_incr() -> xbdback_co_main_loop()
* |
- * xbdback_co_io_gotreq()--+--> xbdback_co_map_io() ---
- * | | |
- * -> xbdback_co_io_loop()----| <- xbdback_co_do_io() <--
- * | | | |
- * | | | |----------> xbdback_co_io_gotio()
- * | | | |
- * | | xbdback_co_main_incr() |
- * | | | |
- * | | xbdback_co_main_loop() |
- * | | |
- * | xbdback_co_io_gotio2() <-----------|
- * | | |
- * | | |----------> xbdback_co_io_gotfrag()
- * | | |
- * -- xbdback_co_io_gotfrag2() <---------|
+ * xbdback_co_io_gotio() -> xbdback_map_shm()
+ * | |
+ * | xbdback_co_main_incr() -> xbdback_co_main_loop()
+ * |
+ * xbdback_co_do_io()
* |
* xbdback_co_main_incr() -> xbdback_co_main_loop()
*/
@@ -192,17 +177,12 @@ struct xbdback_instance {
* continuation-ness (see above).
*/
RING_IDX xbdi_req_prod; /* limit on request indices */
- xbdback_cont_t xbdi_cont, xbdi_cont_aux;
+ xbdback_cont_t xbdi_cont;
/* _request state: track requests fetched from ring */
struct xbdback_request *xbdi_req; /* if NULL, ignore following */
blkif_request_t xbdi_xen_req;
- int xbdi_segno;
/* _io state: I/O associated to this instance */
- struct xbdback_io *xbdi_io; /* if NULL, ignore next field */
- daddr_t xbdi_next_sector;
- uint8_t xbdi_last_fs, xbdi_this_fs; /* first sectors */
- uint8_t xbdi_last_ls, xbdi_this_ls; /* last sectors */
- grant_ref_t xbdi_thisgrt, xbdi_lastgrt; /* grants */
+ struct xbdback_io *xbdi_io;
/* other state */
int xbdi_same_page; /* are we merging two segments on the same page? */
uint xbdi_pendingreqs; /* number of I/O in fly */
@@ -223,20 +203,6 @@ static SLIST_HEAD(, xbdback_instance) xb
static kmutex_t xbdback_lock;
/*
- * For each request from a guest, a xbdback_request is allocated from
- * a pool. This will describe the request until completion. The
- * request may require multiple IO operations to perform, so the
- * per-IO information is not stored here.
- */
-struct xbdback_request {
- struct xbdback_instance *rq_xbdi; /* our xbd instance */
- uint64_t rq_id;
- int rq_iocount; /* reference count; or, number of outstanding I/O's */
- int rq_ioerrs;
- uint8_t rq_operation;
-};
-
-/*
* For each I/O operation associated with one of those requests, an
* xbdback_io is allocated from a pool. It may correspond to multiple
* Xen disk requests, or parts of them, if several arrive at once that
@@ -246,56 +212,35 @@ struct xbdback_io {
/* The instance pointer is duplicated for convenience. */
struct xbdback_instance *xio_xbdi; /* our xbd instance */
uint8_t xio_operation;
+ uint64_t xio_id;
union {
struct {
struct buf xio_buf; /* our I/O */
- /* xbd requests involved */
- SLIST_HEAD(, xbdback_fragment) xio_rq;
/* the virtual address to map the request at */
vaddr_t xio_vaddr;
struct xbdback_va *xio_xv;
+ vaddr_t xio_start_offset; /* I/O start offset */
/* grants to map */
grant_ref_t xio_gref[XENSHM_MAX_PAGES_PER_REQUEST];
/* grants release */
grant_handle_t xio_gh[XENSHM_MAX_PAGES_PER_REQUEST];
uint16_t xio_nrma; /* number of guest pages */
- uint16_t xio_mapped; /* == 1: grants are mapped */
} xio_rw;
- uint64_t xio_flush_id;
} u;
};
#define xio_buf u.xio_rw.xio_buf
-#define xio_rq u.xio_rw.xio_rq
#define xio_vaddr u.xio_rw.xio_vaddr
+#define xio_start_offset u.xio_rw.xio_start_offset
#define xio_xv u.xio_rw.xio_xv
#define xio_gref u.xio_rw.xio_gref
#define xio_gh u.xio_rw.xio_gh
#define xio_nrma u.xio_rw.xio_nrma
-#define xio_mapped u.xio_rw.xio_mapped
-
-#define xio_flush_id u.xio_flush_id
-
-/*
- * Rather than having the xbdback_io keep an array of the
- * xbdback_requests involved, since the actual number will probably be
- * small but might be as large as BLKIF_RING_SIZE, use a list. This
- * would be threaded through xbdback_request, but one of them might be
- * part of multiple I/O's, alas.
- */
-struct xbdback_fragment {
- struct xbdback_request *car;
- SLIST_ENTRY(xbdback_fragment) cdr;
-};
/*
* Pools to manage the chain of block requests and I/Os fragments
* submitted by frontend.
*/
-/* XXXSMP */
-static struct xbdback_pool {
- struct pool_cache pc;
- struct timeval last_warning;
-} xbdback_request_pool, xbdback_io_pool, xbdback_fragment_pool;
+static struct pool_cache xbdback_io_pool;
/* Interval between reports of I/O errors from frontend */
static const struct timeval xbdback_err_intvl = { 1, 0 };
@@ -320,22 +265,14 @@ static bool xbdif_lookup(domid_t, uint32
static void *xbdback_co_main(struct xbdback_instance *, void *);
static void *xbdback_co_main_loop(struct xbdback_instance *, void *);
static void *xbdback_co_main_incr(struct xbdback_instance *, void *);
-static void *xbdback_co_main_done(struct xbdback_instance *, void *);
static void *xbdback_co_main_done2(struct xbdback_instance *, void *);
static void *xbdback_co_cache_flush(struct xbdback_instance *, void *);
-static void *xbdback_co_cache_flush2(struct xbdback_instance *, void *);
static void *xbdback_co_cache_doflush(struct xbdback_instance *, void *);
static void *xbdback_co_io(struct xbdback_instance *, void *);
-static void *xbdback_co_io_gotreq(struct xbdback_instance *, void *);
-static void *xbdback_co_io_loop(struct xbdback_instance *, void *);
static void *xbdback_co_io_gotio(struct xbdback_instance *, void *);
-static void *xbdback_co_io_gotio2(struct xbdback_instance *, void *);
-static void *xbdback_co_io_gotfrag(struct xbdback_instance *, void *);
-static void *xbdback_co_io_gotfrag2(struct xbdback_instance *, void *);
-static void *xbdback_co_map_io(struct xbdback_instance *, void *);
static void *xbdback_co_do_io(struct xbdback_instance *, void *);
static void xbdback_io_error(struct xbdback_io *, int);
@@ -345,9 +282,9 @@ static void xbdback_send_reply(struct xb
static void *xbdback_map_shm(struct xbdback_io *);
static void xbdback_unmap_shm(struct xbdback_io *);
-static void *xbdback_pool_get(struct xbdback_pool *,
+static void *xbdback_pool_get(struct pool_cache *,
struct xbdback_instance *);
-static void xbdback_pool_put(struct xbdback_pool *, void *);
+static void xbdback_pool_put(struct pool_cache *, void *);
static void xbdback_thread(void *);
static void xbdback_wakeup_thread(struct xbdback_instance *);
static void xbdback_trampoline(struct xbdback_instance *, void *);
@@ -369,21 +306,12 @@ xbdbackattach(int n)
SLIST_INIT(&xbdback_instances);
mutex_init(&xbdback_lock, MUTEX_DEFAULT, IPL_NONE);
- pool_cache_bootstrap(&xbdback_request_pool.pc,
- sizeof(struct xbdback_request), 0, 0, 0, "xbbrp", NULL,
- IPL_SOFTBIO, NULL, NULL, NULL);
- pool_cache_bootstrap(&xbdback_io_pool.pc,
+ pool_cache_bootstrap(&xbdback_io_pool,
sizeof(struct xbdback_io), 0, 0, 0, "xbbip", NULL,
IPL_SOFTBIO, NULL, NULL, NULL);
- pool_cache_bootstrap(&xbdback_fragment_pool.pc,
- sizeof(struct xbdback_fragment), 0, 0, 0, "xbbfp", NULL,
- IPL_SOFTBIO, NULL, NULL, NULL);
/* we allocate enough to handle a whole ring at once */
- pool_prime(&xbdback_request_pool.pc.pc_pool, BLKIF_RING_SIZE);
- pool_prime(&xbdback_io_pool.pc.pc_pool, BLKIF_RING_SIZE);
- pool_prime(&xbdback_fragment_pool.pc.pc_pool,
- BLKIF_MAX_SEGMENTS_PER_REQUEST * BLKIF_RING_SIZE);
+ pool_prime(&xbdback_io_pool.pc_pool, BLKIF_RING_SIZE);
xenbus_backend_register(&xbd_backend_driver);
}
@@ -1074,7 +1002,8 @@ xbdback_co_main_loop(struct xbdback_inst
break;
}
} else {
- xbdi->xbdi_cont = xbdback_co_main_done;
+ KASSERT(xbdi->xbdi_io == NULL);
+ xbdi->xbdi_cont = xbdback_co_main_done2;
}
return xbdi;
}
@@ -1112,25 +1041,6 @@ xbdback_co_main_incr(struct xbdback_inst
}
/*
- * Ring processing is over. If there are any I/O still present for this
- * instance, handle them first.
- */
-static void *
-xbdback_co_main_done(struct xbdback_instance *xbdi, void *obj)
-{
- (void)obj;
- if (xbdi->xbdi_io != NULL) {
- KASSERT(xbdi->xbdi_io->xio_operation == BLKIF_OP_READ ||
- xbdi->xbdi_io->xio_operation == BLKIF_OP_WRITE);
- xbdi->xbdi_cont = xbdback_co_map_io;
- xbdi->xbdi_cont_aux = xbdback_co_main_done2;
- } else {
- xbdi->xbdi_cont = xbdback_co_main_done2;
- }
- return xbdi;
-}
-
-/*
* Check for requests in the instance's ring. In case there are, start again
* from the beginning. If not, stall.
*/
@@ -1139,6 +1049,7 @@ xbdback_co_main_done2(struct xbdback_ins
{
int work_to_do;
+ KASSERT(xbdi->xbdio_io == NULL);
RING_FINAL_CHECK_FOR_REQUESTS(&xbdi->xbdi_ring.ring_n, work_to_do);
if (work_to_do)
xbdi->xbdi_cont = xbdback_co_main;
@@ -1152,29 +1063,8 @@ xbdback_co_main_done2(struct xbdback_ins
* Frontend requested a cache flush operation.
*/
static void *
-xbdback_co_cache_flush(struct xbdback_instance *xbdi, void *obj)
-{
- (void)obj;
-
- XENPRINTF(("xbdback_co_cache_flush %p %p\n", xbdi, obj));
- if (xbdi->xbdi_io != NULL) {
- /* Some I/Os are required for this instance. Process them. */
- KASSERT(xbdi->xbdi_io->xio_operation == BLKIF_OP_READ ||
- xbdi->xbdi_io->xio_operation == BLKIF_OP_WRITE);
- KASSERT(xbdi->xbdi_pendingreqs > 0);
- xbdi->xbdi_cont = xbdback_co_map_io;
- xbdi->xbdi_cont_aux = xbdback_co_cache_flush2;
- } else {
- xbdi->xbdi_cont = xbdback_co_cache_flush2;
- }
- return xbdi;
-}
-
-static void *
-xbdback_co_cache_flush2(struct xbdback_instance *xbdi, void *obj)
+xbdback_co_cache_flush(struct xbdback_instance *xbdi, void *obj __unused)
{
- (void)obj;
- XENPRINTF(("xbdback_co_cache_flush2 %p %p\n", xbdi, obj));
if (xbdi->xbdi_pendingreqs > 0) {
/*
* There are pending requests.
@@ -1198,7 +1088,7 @@ xbdback_co_cache_doflush(struct xbdback_
xbd_io = xbdi->xbdi_io = obj;
xbd_io->xio_xbdi = xbdi;
xbd_io->xio_operation = xbdi->xbdi_xen_req.operation;
- xbd_io->xio_flush_id = xbdi->xbdi_xen_req.id;
+ xbd_io->xio_id = xbdi->xbdi_xen_req.id;
xbdi->xbdi_cont = xbdback_co_do_io;
return xbdi;
}
@@ -1240,8 +1130,6 @@ xbdback_co_io(struct xbdback_instance *x
}
}
- xbdi->xbdi_segno = 0;
-
/* copy request segments */
switch(xbdi->xbdi_proto) {
case XBDIP_NATIVE:
@@ -1261,169 +1149,51 @@ xbdback_co_io(struct xbdback_instance *x
break;
}
- xbdi->xbdi_cont = xbdback_co_io_gotreq;
- return xbdback_pool_get(&xbdback_request_pool, xbdi);
+ KASSERT(xbdi->xbdi_io == NULL);
+ xbdi->xbdi_cont = xbdback_co_io_gotio;
+ return xbdback_pool_get(&xbdback_io_pool, xbdi);
end:
xbdback_send_reply(xbdi, xbdi->xbdi_xen_req.id,
- xbdi->xbdi_xen_req.operation, error);
+ xbdi->xbdi_xen_req.operation,
+ (error == EROFS) ? BLKIF_RSP_EOPNOTSUPP : BLKIF_RSP_ERROR);
xbdi->xbdi_cont = xbdback_co_main_incr;
return xbdi;
}
-/*
- * We have fetched segment requests from the ring. In case there are already
- * I/Os prepared for this instance, we can try coalescing the requests
- * with these I/Os.
- */
-static void *
-xbdback_co_io_gotreq(struct xbdback_instance *xbdi, void *obj)
-{
- struct xbdback_request *xrq;
-
- xrq = xbdi->xbdi_req = obj;
-
- xrq->rq_xbdi = xbdi;
- xrq->rq_iocount = 0;
- xrq->rq_ioerrs = 0;
- xrq->rq_id = xbdi->xbdi_xen_req.id;
- xrq->rq_operation = xbdi->xbdi_xen_req.operation;
- KASSERT(xbdi->xbdi_req->rq_operation == BLKIF_OP_READ ||
- xbdi->xbdi_req->rq_operation == BLKIF_OP_WRITE);
-
- /*
- * Request-level reasons not to coalesce: different device,
- * different op, or noncontiguous disk sectors (vs. previous
- * request handed to us).
- */
- xbdi->xbdi_cont = xbdback_co_io_loop;
- if (xbdi->xbdi_io != NULL) {
- struct xbdback_request *last_req;
- last_req = SLIST_FIRST(&xbdi->xbdi_io->xio_rq)->car;
- XENPRINTF(("xbdback_io domain %d: hoping for sector %" PRIu64
- "; got %" PRIu64 "\n", xbdi->xbdi_domid,
- xbdi->xbdi_next_sector,
- xbdi->xbdi_xen_req.sector_number));
- if ((xrq->rq_operation != last_req->rq_operation)
- || (xbdi->xbdi_xen_req.sector_number !=
- xbdi->xbdi_next_sector)) {
- XENPRINTF(("xbdback_io domain %d: segment break\n",
- xbdi->xbdi_domid));
- xbdi->xbdi_next_sector =
- xbdi->xbdi_xen_req.sector_number;
- KASSERT(xbdi->xbdi_io->xio_operation == BLKIF_OP_READ ||
- xbdi->xbdi_io->xio_operation == BLKIF_OP_WRITE);
- xbdi->xbdi_cont_aux = xbdback_co_io_loop;
- xbdi->xbdi_cont = xbdback_co_map_io;
- }
- } else {
- xbdi->xbdi_next_sector = xbdi->xbdi_xen_req.sector_number;
- }
- return xbdi;
-}
-
-/* Handle coalescing of multiple segment requests into one I/O work */
-static void *
-xbdback_co_io_loop(struct xbdback_instance *xbdi, void *obj)
-{
- (void)obj;
- KASSERT(xbdi->xbdi_req->rq_operation == BLKIF_OP_READ ||
- xbdi->xbdi_req->rq_operation == BLKIF_OP_WRITE);
- if (xbdi->xbdi_segno < xbdi->xbdi_xen_req.nr_segments) {
- uint8_t this_fs, this_ls, last_ls;
- grant_ref_t thisgrt;
- /*
- * Segment-level reason to coalesce: handling full
- * pages, or adjacent sector ranges from the same page
- * (and yes, this latter does happen). But not if the
- * array of client pseudo-physical pages is full.
- */
- this_fs = xbdi->xbdi_xen_req.seg[xbdi->xbdi_segno].first_sect;
- this_ls = xbdi->xbdi_xen_req.seg[xbdi->xbdi_segno].last_sect;
- thisgrt = xbdi->xbdi_xen_req.seg[xbdi->xbdi_segno].gref;
- XENPRINTF(("xbdback_io domain %d: "
- "first,last_sect[%d]=0%o,0%o\n",
- xbdi->xbdi_domid, xbdi->xbdi_segno,
- this_fs, this_ls));
- last_ls = xbdi->xbdi_last_ls = xbdi->xbdi_this_ls;
- xbdi->xbdi_this_fs = this_fs;
- xbdi->xbdi_this_ls = this_ls;
- xbdi->xbdi_thisgrt = thisgrt;
- if (xbdi->xbdi_io != NULL) {
- if (last_ls == VBD_MAXSECT
- && this_fs == 0
- && xbdi->xbdi_io->xio_nrma
- < XENSHM_MAX_PAGES_PER_REQUEST) {
- xbdi->xbdi_same_page = 0;
- } else if (last_ls + 1
- == this_fs
-#ifdef notyet
- && (last_fas & ~PAGE_MASK)
- == (this_fas & ~PAGE_MASK)
-#else
- && 0 /* can't know frame number yet */
-#endif
- ) {
-#ifdef DEBUG
- if (ratecheck(&xbdi->xbdi_lastfragio_time,
- &xbdback_fragio_intvl))
- printf("%s: domain is sending"
- " excessively fragmented I/O\n",
- xbdi->xbdi_name);
-#endif
- printf("xbdback_io: would maybe glue "
- "same page sec %d (%d->%d)\n",
- xbdi->xbdi_segno, this_fs, this_ls);
- XENPRINTF(("xbdback_io domain %d: glue same "
- "page", xbdi->xbdi_domid));
- panic("notyet!");
- xbdi->xbdi_same_page = 1;
- } else {
- KASSERT(xbdi->xbdi_io->xio_operation ==
- BLKIF_OP_READ ||
- xbdi->xbdi_io->xio_operation ==
- BLKIF_OP_WRITE);
- xbdi->xbdi_cont_aux = xbdback_co_io_loop;
- xbdi->xbdi_cont = xbdback_co_map_io;
- return xbdi;
- }
- } else
- xbdi->xbdi_same_page = 0;
-
- if (xbdi->xbdi_io == NULL) {
- xbdi->xbdi_cont = xbdback_co_io_gotio;
- return xbdback_pool_get(&xbdback_io_pool, xbdi);
- } else {
- xbdi->xbdi_cont = xbdback_co_io_gotio2;
- }
- } else {
- /* done with the loop over segments; get next request */
- xbdi->xbdi_cont = xbdback_co_main_incr;
- }
- return xbdi;
-}
-
/* Prepare an I/O buffer for a xbdback instance */
static void *
xbdback_co_io_gotio(struct xbdback_instance *xbdi, void *obj)
{
struct xbdback_io *xbd_io;
- vaddr_t start_offset; /* start offset in vm area */
int buf_flags;
+ size_t bcount;
+ blkif_request_t *req;
xbdi_get(xbdi);
atomic_inc_uint(&xbdi->xbdi_pendingreqs);
+ req = &xbdi->xbdi_xen_req;
xbd_io = xbdi->xbdi_io = obj;
+ memset(xbd_io, 0, sizeof(*xbd_io));
buf_init(&xbd_io->xio_buf);
xbd_io->xio_xbdi = xbdi;
- SLIST_INIT(&xbd_io->xio_rq);
- xbd_io->xio_nrma = 0;
- xbd_io->xio_mapped = 0;
- xbd_io->xio_operation = xbdi->xbdi_xen_req.operation;
+ xbd_io->xio_operation = req->operation;
+ xbd_io->xio_id = req->id;
- start_offset = xbdi->xbdi_this_fs * VBD_BSIZE;
- KASSERT(start_offset < PAGE_SIZE);
+ /* Process segments */
+ bcount = 0;
+ for (int i = 0; i < req->nr_segments; i++) {
+ xbd_io->xio_gref[i] = req->seg[i].gref;
+ bcount += (req->seg[i].last_sect - req->seg[i].first_sect + 1)
+ * VBD_BSIZE;
+ }
+ KASSERT(bcount <= MAXPHYS);
+ xbd_io->xio_nrma = req->nr_segments;
+
+ xbd_io->xio_start_offset = req->seg[0].first_sect * VBD_BSIZE;
+ KASSERT(xbd_io->xio_start_offset < PAGE_SIZE);
+ KASSERT(bcount + xbd_io->xio_start_offset < VBD_VA_SIZE);
if (xbdi->xbdi_xen_req.operation == BLKIF_OP_WRITE) {
buf_flags = B_WRITE;
@@ -1439,97 +1209,11 @@ xbdback_co_io_gotio(struct xbdback_insta
xbd_io->xio_buf.b_vp = xbdi->xbdi_vp;
xbd_io->xio_buf.b_objlock = xbdi->xbdi_vp->v_interlock;
xbd_io->xio_buf.b_dev = xbdi->xbdi_dev;
- xbd_io->xio_buf.b_blkno = xbdi->xbdi_next_sector;
- xbd_io->xio_buf.b_bcount = 0;
- xbd_io->xio_buf.b_data = (void *)start_offset;
+ xbd_io->xio_buf.b_blkno = req->sector_number;
+ xbd_io->xio_buf.b_bcount = bcount;
+ xbd_io->xio_buf.b_data = NULL;
xbd_io->xio_buf.b_private = xbd_io;
- xbdi->xbdi_cont = xbdback_co_io_gotio2;
- return xbdi;
-}
-
-/* Manage fragments */
-static void *
-xbdback_co_io_gotio2(struct xbdback_instance *xbdi, void *obj)
-{
- (void)obj;
- if (xbdi->xbdi_segno == 0 || SLIST_EMPTY(&xbdi->xbdi_io->xio_rq)) {
- /* if this is the first segment of a new request */
- /* or if it's the first segment of the io */
- xbdi->xbdi_cont = xbdback_co_io_gotfrag;
- return xbdback_pool_get(&xbdback_fragment_pool, xbdi);
- }
- xbdi->xbdi_cont = xbdback_co_io_gotfrag2;
- return xbdi;
-}
-
-/* Prepare the instance for its first fragment */
-static void *
-xbdback_co_io_gotfrag(struct xbdback_instance *xbdi, void *obj)
-{
- struct xbdback_fragment *xbd_fr;
-
- xbd_fr = obj;
- xbd_fr->car = xbdi->xbdi_req;
- SLIST_INSERT_HEAD(&xbdi->xbdi_io->xio_rq, xbd_fr, cdr);
- ++xbdi->xbdi_req->rq_iocount;
-
- xbdi->xbdi_cont = xbdback_co_io_gotfrag2;
- return xbdi;
-}
-
-/* Last routine to manage segments fragments for one I/O */
-static void *
-xbdback_co_io_gotfrag2(struct xbdback_instance *xbdi, void *obj)
-{
- struct xbdback_io *xbd_io;
- int seg_size;
- uint8_t this_fs, this_ls;
-
- this_fs = xbdi->xbdi_this_fs;
- this_ls = xbdi->xbdi_this_ls;
- xbd_io = xbdi->xbdi_io;
- seg_size = this_ls - this_fs + 1;
-
- if (seg_size < 0) {
- if (ratecheck(&xbdi->xbdi_lasterr_time, &xbdback_err_intvl)) {
- printf("xbdback_io domain %d: negative-size request "
- "(%d %d)\n",
- xbdi->xbdi_domid, this_ls, this_fs);
- }
- xbdback_io_error(xbdi->xbdi_io, EINVAL);
- xbdi->xbdi_io = NULL;
- xbdi->xbdi_cont = xbdback_co_main_incr;
- return xbdi;
- }
-
- if (!xbdi->xbdi_same_page) {
- XENPRINTF(("xbdback_io domain %d: appending grant %u\n",
- xbdi->xbdi_domid, (u_int)xbdi->xbdi_thisgrt));
- xbd_io->xio_gref[xbd_io->xio_nrma++] = xbdi->xbdi_thisgrt;
- }
-
- xbd_io->xio_buf.b_bcount += (daddr_t)(seg_size * VBD_BSIZE);
- XENPRINTF(("xbdback_io domain %d: start sect %ld size %d\n",
- xbdi->xbdi_domid, (long)xbdi->xbdi_next_sector, seg_size));
-
- /* Finally, the end of the segment loop! */
- xbdi->xbdi_next_sector += seg_size;
- ++xbdi->xbdi_segno;
- xbdi->xbdi_cont = xbdback_co_io_loop;
- return xbdi;
-}
-
-/*
- * Map the different I/O requests in backend's VA space.
- */
-static void *
-xbdback_co_map_io(struct xbdback_instance *xbdi, void *obj)
-{
- (void)obj;
- XENPRINTF(("xbdback_io domain %d: flush sect %ld size %d ptr 0x%lx\n",
- xbdi->xbdi_domid, (long)xbdi->xbdi_io->xio_buf.b_blkno,
- (int)xbdi->xbdi_io->xio_buf.b_bcount, (long)xbdi->xbdi_io));
xbdi->xbdi_cont = xbdback_co_do_io;
return xbdback_map_shm(xbdi->xbdi_io);
}
@@ -1549,7 +1233,6 @@ static void *
xbdback_co_do_io(struct xbdback_instance *xbdi, void *obj)
{
struct xbdback_io *xbd_io = xbdi->xbdi_io;
- vaddr_t start_offset;
int nsegs __diagused;
switch (xbd_io->xio_operation) {
@@ -1569,7 +1252,7 @@ xbdback_co_do_io(struct xbdback_instance
error = BLKIF_RSP_ERROR;
} else
error = BLKIF_RSP_OKAY;
- xbdback_send_reply(xbdi, xbd_io->xio_flush_id,
+ xbdback_send_reply(xbdi, xbd_io->xio_id,
xbd_io->xio_operation, error);
xbdback_pool_put(&xbdback_io_pool, xbd_io);
xbdi_put(xbdi);
@@ -1579,30 +1262,18 @@ xbdback_co_do_io(struct xbdback_instance
}
case BLKIF_OP_READ:
case BLKIF_OP_WRITE:
- start_offset = (vaddr_t)xbd_io->xio_buf.b_data;
- KASSERT(xbd_io->xio_buf.b_bcount + start_offset < VBD_VA_SIZE);
xbd_io->xio_buf.b_data = (void *)
- (start_offset + xbd_io->xio_vaddr);
-#ifdef DIAGNOSTIC
- nsegs = round_page(start_offset + xbd_io->xio_buf.b_bcount)
- >> PAGE_SHIFT;
- if (nsegs > xbd_io->xio_nrma) {
- printf("xbdback_co_do_io: vaddr %#" PRIxVADDR
- " bcount %#x doesn't fit in %d pages\n",
- start_offset, xbd_io->xio_buf.b_bcount,
- xbd_io->xio_nrma);
- panic("xbdback_co_do_io: not enough pages");
- }
-#endif
+ (xbd_io->xio_vaddr + xbd_io->xio_start_offset);
+
if ((xbd_io->xio_buf.b_flags & B_READ) == 0) {
mutex_enter(xbd_io->xio_buf.b_vp->v_interlock);
xbd_io->xio_buf.b_vp->v_numoutput++;
mutex_exit(xbd_io->xio_buf.b_vp->v_interlock);
}
- bdev_strategy(&xbd_io->xio_buf);
/* will call xbdback_iodone() asynchronously when done */
+ bdev_strategy(&xbd_io->xio_buf);
xbdi->xbdi_io = NULL;
- xbdi->xbdi_cont = xbdi->xbdi_cont_aux;
+ xbdi->xbdi_cont = xbdback_co_main_incr;
return xbdi;
default:
/* Should never happen */
@@ -1622,7 +1293,7 @@ xbdback_iodone(struct buf *bp)
{
struct xbdback_io *xbd_io;
struct xbdback_instance *xbdi;
- int errp;
+ int status;
KERNEL_LOCK(1, NULL); /* XXXSMP */
@@ -1632,49 +1303,19 @@ xbdback_iodone(struct buf *bp)
XENPRINTF(("xbdback_io domain %d: iodone ptr 0x%lx\n",
xbdi->xbdi_domid, (long)xbd_io));
- if (xbd_io->xio_mapped == 1)
+ KASSERT(bp->b_error != 0 || xbd_io->xio_xv != NULL);
+ if (xbd_io->xio_xv != NULL)
xbdback_unmap_shm(xbd_io);
if (bp->b_error != 0) {
printf("xbd IO domain %d: error %d\n",
xbdi->xbdi_domid, bp->b_error);
- errp = 1;
+ status = BLKIF_RSP_ERROR;
} else
- errp = 0;
+ status = BLKIF_RSP_OKAY;
- /* for each constituent xbd request */
- while(!SLIST_EMPTY(&xbd_io->xio_rq)) {
- struct xbdback_fragment *xbd_fr;
- struct xbdback_request *xbd_req;
- struct xbdback_instance *rxbdi __diagused;
- int error;
-
- xbd_fr = SLIST_FIRST(&xbd_io->xio_rq);
- xbd_req = xbd_fr->car;
- SLIST_REMOVE_HEAD(&xbd_io->xio_rq, cdr);
- xbdback_pool_put(&xbdback_fragment_pool, xbd_fr);
-
- if (errp)
- ++xbd_req->rq_ioerrs;
-
- /* finalize it only if this was its last I/O */
- if (--xbd_req->rq_iocount > 0)
- continue;
-
- rxbdi = xbd_req->rq_xbdi;
- KASSERT(xbdi == rxbdi);
-
- error = xbd_req->rq_ioerrs > 0
- ? BLKIF_RSP_ERROR
- : BLKIF_RSP_OKAY;
-
- XENPRINTF(("xbdback_io domain %d: end request %"PRIu64
- " error=%d\n",
- xbdi->xbdi_domid, xbd_req->rq_id, error));
- xbdback_send_reply(xbdi, xbd_req->rq_id,
- xbd_req->rq_operation, error);
- xbdback_pool_put(&xbdback_request_pool, xbd_req);
- }
+ xbdback_send_reply(xbdi, xbd_io->xio_id, xbd_io->xio_operation, status);
+
xbdi_put(xbdi);
atomic_dec_uint(&xbdi->xbdi_pendingreqs);
buf_destroy(&xbd_io->xio_buf);
@@ -1759,7 +1400,6 @@ static void *
xbdback_map_shm(struct xbdback_io *xbd_io)
{
struct xbdback_instance *xbdi = xbd_io->xio_xbdi;
- struct xbdback_request *xbd_rq;
int error, s;
#ifdef XENDEBUG_VBD
@@ -1770,11 +1410,7 @@ xbdback_map_shm(struct xbdback_io *xbd_i
}
#endif
- KASSERT(xbd_io->xio_mapped == 0);
-
s = splvm(); /* XXXSMP */
- xbd_rq = SLIST_FIRST(&xbd_io->xio_rq)->car;
-
xbd_io->xio_xv = SLIST_FIRST(&xbdi->xbdi_va_free);
KASSERT(xbd_io->xio_xv != NULL);
SLIST_REMOVE_HEAD(&xbdi->xbdi_va_free, xv_next);
@@ -1783,7 +1419,7 @@ xbdback_map_shm(struct xbdback_io *xbd_i
error = xen_shm_map(xbd_io->xio_nrma, xbdi->xbdi_domid,
xbd_io->xio_gref, xbd_io->xio_vaddr, xbd_io->xio_gh,
- (xbd_rq->rq_operation == BLKIF_OP_WRITE) ? XSHM_RO : 0);
+ (xbd_io->xio_operation == BLKIF_OP_WRITE) ? XSHM_RO : 0);
switch(error) {
case 0:
@@ -1794,7 +1430,6 @@ xbdback_map_shm(struct xbdback_io *xbd_i
}
printf("\n");
#endif
- xbd_io->xio_mapped = 1;
return xbdi;
default:
if (ratecheck(&xbdi->xbdi_lasterr_time, &xbdback_err_intvl)) {
@@ -1825,8 +1460,7 @@ xbdback_unmap_shm(struct xbdback_io *xbd
printf("\n");
#endif
- KASSERT(xbd_io->xio_mapped == 1);
- xbd_io->xio_mapped = 0;
+ KASSERT(xbd_io->xio_xv != NULL);
xen_shm_unmap(xbd_io->xio_vaddr, xbd_io->xio_nrma,
xbd_io->xio_gh);
SLIST_INSERT_HEAD(&xbdi->xbdi_va_free, xbd_io->xio_xv, xv_next);
@@ -1836,17 +1470,17 @@ xbdback_unmap_shm(struct xbdback_io *xbd
/* Obtain memory from a pool */
static void *
-xbdback_pool_get(struct xbdback_pool *pp,
+xbdback_pool_get(struct pool_cache *pc,
struct xbdback_instance *xbdi)
{
- return pool_cache_get(&pp->pc, PR_WAITOK);
+ return pool_cache_get(pc, PR_WAITOK);
}
/* Restore memory to a pool */
static void
-xbdback_pool_put(struct xbdback_pool *pp, void *item)
+xbdback_pool_put(struct pool_cache *pc, void *item)
{
- pool_cache_put(&pp->pc, item);
+ pool_cache_put(pc, item);
}
/*
