diff options
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/xen/Makefile | 1 | ||||
| -rw-r--r-- | drivers/xen/blkback/Makefile | 3 | ||||
| -rw-r--r-- | drivers/xen/blkback/blkback.c | 759 | ||||
| -rw-r--r-- | drivers/xen/blkback/common.h | 142 | ||||
| -rw-r--r-- | drivers/xen/blkback/interface.c | 185 | ||||
| -rw-r--r-- | drivers/xen/blkback/vbd.c | 162 | ||||
| -rw-r--r-- | drivers/xen/blkback/xenbus.c | 562 |
8 files changed, 0 insertions, 1822 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index fb1af628cbf..a59638b37c1 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -37,14 +37,6 @@ config XEN_BACKEND Support for backend device drivers that provide I/O services to other virtual machines. -config XEN_BLKDEV_BACKEND - tristate "Block-device backend driver" - depends on XEN_BACKEND && BLOCK - help - The block-device backend driver allows the kernel to export its - block devices to other guests via a high-performance shared-memory - interface. - config XENFS tristate "Xen filesystem" default y diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 29c0a416f08..f420f1ff7f1 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -11,7 +11,6 @@ obj-$(CONFIG_XEN_BALLOON) += xen-balloon.o obj-$(CONFIG_XEN_DEV_EVTCHN) += xen-evtchn.o obj-$(CONFIG_XEN_GNTDEV) += xen-gntdev.o obj-$(CONFIG_XEN_GRANT_DEV_ALLOC) += xen-gntalloc.o -obj-$(CONFIG_XEN_BLKDEV_BACKEND) += blkback/ obj-$(CONFIG_XENFS) += xenfs/ obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o obj-$(CONFIG_XEN_PLATFORM_PCI) += xen-platform-pci.o diff --git a/drivers/xen/blkback/Makefile b/drivers/xen/blkback/Makefile deleted file mode 100644 index f1ae1ff07a4..00000000000 --- a/drivers/xen/blkback/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -obj-$(CONFIG_XEN_BLKDEV_BACKEND) := xen-blkback.o - -xen-blkback-y := blkback.o xenbus.o interface.o vbd.o diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c deleted file mode 100644 index 59a2bae0f35..00000000000 --- a/drivers/xen/blkback/blkback.c +++ /dev/null @@ -1,759 +0,0 @@ -/****************************************************************************** - * - * Back-end of the driver for virtual block devices. This portion of the - * driver exports a 'unified' block-device interface that can be accessed - * by any operating system that implements a compatible front end. A - * reference front-end implementation can be found in: - * drivers/block/xen-blkfront.c - * - * Copyright (c) 2003-2004, Keir Fraser & Steve Hand - * Copyright (c) 2005, Christopher Clark - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation; or, when distributed - * separately from the Linux kernel or incorporated into other - * software packages, subject to the following license: - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this source file (the "Software"), to deal in the Software without - * restriction, including without limitation the rights to use, copy, modify, - * merge, publish, distribute, sublicense, and/or sell copies of the Software, - * and to permit persons to whom the Software is furnished to do so, subject to - * the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS - * IN THE SOFTWARE. - */ - -#include <linux/spinlock.h> -#include <linux/kthread.h> -#include <linux/list.h> -#include <linux/delay.h> -#include <linux/freezer.h> - -#include <xen/events.h> -#include <xen/page.h> -#include <asm/xen/hypervisor.h> -#include <asm/xen/hypercall.h> -#include "common.h" - -#define WRITE_BARRIER (REQ_WRITE | REQ_FLUSH | REQ_FUA) - -/* - * These are rather arbitrary. They are fairly large because adjacent requests - * pulled from a communication ring are quite likely to end up being part of - * the same scatter/gather request at the disc. - * - * ** TRY INCREASING 'blkif_reqs' IF WRITE SPEEDS SEEM TOO LOW ** - * - * This will increase the chances of being able to write whole tracks. - * 64 should be enough to keep us competitive with Linux. - */ -static int blkif_reqs = 64; -module_param_named(reqs, blkif_reqs, int, 0); -MODULE_PARM_DESC(reqs, "Number of blkback requests to allocate"); - -/* Run-time switchable: /sys/module/blkback/parameters/ */ -static unsigned int log_stats; -static unsigned int debug_lvl; -module_param(log_stats, int, 0644); -module_param(debug_lvl, int, 0644); - -/* - * Each outstanding request that we've passed to the lower device layers has a - * 'pending_req' allocated to it. Each buffer_head that completes decrements - * the pendcnt towards zero. When it hits zero, the specified domain has a - * response queued for it, with the saved 'id' passed back. - */ -struct pending_req { - struct blkif_st *blkif; - u64 id; - int nr_pages; - atomic_t pendcnt; - unsigned short operation; - int status; - struct list_head free_list; -}; - -#define BLKBACK_INVALID_HANDLE (~0) - -struct xen_blkbk { - struct pending_req *pending_reqs; - /* List of all 'pending_req' available */ - struct list_head pending_free; - /* And its spinlock. */ - spinlock_t pending_free_lock; - wait_queue_head_t pending_free_wq; - /* The list of all pages that are available. */ - struct page **pending_pages; - /* And the grant handles that are available. */ - grant_handle_t *pending_grant_handles; -}; - -static struct xen_blkbk *blkbk; - -/* - * Little helpful macro to figure out the index and virtual address of the - * pending_pages[..]. For each 'pending_req' we have have up to - * BLKIF_MAX_SEGMENTS_PER_REQUEST (11) pages. The seg would be from 0 through - * 10 and would index in the pending_pages[..]. */ -static inline int vaddr_pagenr(struct pending_req *req, int seg) -{ - return (req - blkbk->pending_reqs) * - BLKIF_MAX_SEGMENTS_PER_REQUEST + seg; -} - -#define pending_page(req, seg) pending_pages[vaddr_pagenr(req, seg)] - -static inline unsigned long vaddr(struct pending_req *req, int seg) -{ - unsigned long pfn = page_to_pfn(blkbk->pending_page(req, seg)); - return (unsigned long)pfn_to_kaddr(pfn); -} - -#define pending_handle(_req, _seg) \ - (blkbk->pending_grant_handles[vaddr_pagenr(_req, _seg)]) - - -static int do_block_io_op(struct blkif_st *blkif); -static void dispatch_rw_block_io(struct blkif_st *blkif, - struct blkif_request *req, - struct pending_req *pending_req); -static void make_response(struct blkif_st *blkif, u64 id, - unsigned short op, int st); - -/* - * Retrieve from the 'pending_reqs' a free pending_req structure to be used. - */ -static struct pending_req *alloc_req(void) -{ - struct pending_req *req = NULL; - unsigned long flags; - - spin_lock_irqsave(&blkbk->pending_free_lock, flags); - if (!list_empty(&blkbk->pending_free)) { - req = list_entry(blkbk->pending_free.next, struct pending_req, - free_list); - list_del(&req->free_list); - } - spin_unlock_irqrestore(&blkbk->pending_free_lock, flags); - return req; -} - -/* - * Return the 'pending_req' structure back to the freepool. We also - * wake up the thread if it was waiting for a free page. - */ -static void free_req(struct pending_req *req) -{ - unsigned long flags; - int was_empty; - - spin_lock_irqsave(&blkbk->pending_free_lock, flags); - was_empty = list_empty(&blkbk->pending_free); - list_add(&req->free_list, &blkbk->pending_free); - spin_unlock_irqrestore(&blkbk->pending_free_lock, flags); - if (was_empty) - wake_up(&blkbk->pending_free_wq); -} - -/* - * Notification from the guest OS. - */ -static void blkif_notify_work(struct blkif_st *blkif) -{ - blkif->waiting_reqs = 1; - wake_up(&blkif->wq); -} - -irqreturn_t blkif_be_int(int irq, void *dev_id) -{ - blkif_notify_work(dev_id); - return IRQ_HANDLED; -} - -/* - * SCHEDULER FUNCTIONS - */ - -static void print_stats(struct blkif_st *blkif) -{ - printk(KERN_DEBUG "%s: oo %3d | rd %4d | wr %4d | br %4d\n", - current->comm, blkif->st_oo_req, - blkif->st_rd_req, blkif->st_wr_req, blkif->st_br_req); - blkif->st_print = jiffies + msecs_to_jiffies(10 * 1000); - blkif->st_rd_req = 0; - blkif->st_wr_req = 0; - blkif->st_oo_req = 0; -} - -int blkif_schedule(void *arg) -{ - struct blkif_st *blkif = arg; - struct vbd *vbd = &blkif->vbd; - - blkif_get(blkif); - - if (debug_lvl) - printk(KERN_DEBUG "%s: started\n", current->comm); - - while (!kthread_should_stop()) { - if (try_to_freeze()) - continue; - if (unlikely(vbd->size != vbd_size(vbd))) - vbd_resize(blkif); - - wait_event_interruptible( - blkif->wq, - blkif->waiting_reqs || kthread_should_stop()); - wait_event_interruptible( - blkbk->pending_free_wq, - !list_empty(&blkbk->pending_free) || - kthread_should_stop()); - - blkif->waiting_reqs = 0; - smp_mb(); /* clear flag *before* checking for work */ - - if (do_block_io_op(blkif)) - blkif->waiting_reqs = 1; - - if (log_stats && time_after(jiffies, blkif->st_print)) - print_stats(blkif); - } - - if (log_stats) - print_stats(blkif); - if (debug_lvl) - printk(KERN_DEBUG "%s: exiting\n", current->comm); - - blkif->xenblkd = NULL; - blkif_put(blkif); - - return 0; -} - -struct seg_buf { - unsigned long buf; - unsigned int nsec; -}; -/* - * Unmap the grant references, and also remove the M2P over-rides - * used in the 'pending_req'. -*/ -static void xen_blkbk_unmap(struct pending_req *req) -{ - struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - unsigned int i, invcount = 0; - grant_handle_t handle; - int ret; - - for (i = 0; i < req->nr_pages; i++) { - handle = pending_handle(req, i); - if (handle == BLKBACK_INVALID_HANDLE) - continue; - gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i), - GNTMAP_host_map, handle); - pending_handle(req, i) = BLKBACK_INVALID_HANDLE; - invcount++; - } - - ret = HYPERVISOR_grant_table_op( - GNTTABOP_unmap_grant_ref, unmap, invcount); - BUG_ON(ret); - /* Note, we use invcount, so nr->pages, so we can't index - * using vaddr(req, i). - */ - for (i = 0; i < invcount; i++) { - ret = m2p_remove_override( - virt_to_page(unmap[i].host_addr), false); - if (ret) { - printk(KERN_ALERT "Failed to remove M2P override for " \ - "%lx\n", (unsigned long)unmap[i].host_addr); - continue; - } - } -} -static int xen_blkbk_map(struct blkif_request *req, struct pending_req *pending_req, - struct seg_buf seg[]) -{ - struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - int i; - int nseg = req->nr_segments; - int ret = 0; - /* Fill out preq.nr_sects with proper amount of sectors, and setup - * assign map[..] with the PFN of the page in our domain with the - * corresponding grant reference for each page. - */ - 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); - } - - ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map, nseg); - BUG_ON(ret); - - /* Now swizzel 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)) { - DPRINTK("invalid buffer -- could not remap it\n"); - map[i].handle = BLKBACK_INVALID_HANDLE; - ret |= 1; - } - - pending_handle(pending_req, i) = map[i].handle; - - if (ret) - continue; - - ret = m2p_add_override(PFN_DOWN(map[i].dev_bus_addr), - blkbk->pending_page(pending_req, i), false); - if (ret) { - printk(KERN_ALERT "Failed to install M2P override for"\ - " %lx (ret: %d)\n", (unsigned long) - map[i].dev_bus_addr, ret); - /* We could switch over to GNTTABOP_copy */ - continue; - } - - seg[i].buf = map[i].dev_bus_addr | - (req->u.rw.seg[i].first_sect << 9); - } - return ret; -} - -/* - * Completion callback on the bio's. Called as bh->b_end_io() - */ - -static void __end_block_io_op(struct pending_req *pending_req, int error) -{ - /* An error fails the entire request. */ - if ((pending_req->operation == BLKIF_OP_WRITE_BARRIER) && - (error == -EOPNOTSUPP)) { - DPRINTK("blkback: write barrier op failed, not supported\n"); - blkback_barrier(XBT_NIL, pending_req->blkif->be, 0); - pending_req->status = BLKIF_RSP_EOPNOTSUPP; - } else if (error) { - DPRINTK("Buffer not up-to-date at end of operation, " - "error=%d\n", error); - pending_req->status = BLKIF_RSP_ERROR; - } - - /* If all of the bio's have completed it is time to unmap - * the grant references associated with 'request' and provide - * the proper response on the ring. - */ - if (atomic_dec_and_test(&pending_req->pendcnt)) { - xen_blkbk_unmap(pending_req); - make_response(pending_req->blkif, pending_req->id, - pending_req->operation, pending_req->status); - blkif_put(pending_req->blkif); - free_req(pending_req); - } -} - -/* - * bio callback. - */ -static void end_block_io_op(struct bio *bio, int error) -{ - __end_block_io_op(bio->bi_private, error); - bio_put(bio); -} - - - -/* - * Function to copy the from the ring buffer the 'struct blkif_request' - * (which has the sectors we want, number of them, grant references, etc), - * and transmute it to the block API to hand it over to the proper block disk. - */ -static int do_block_io_op(struct blkif_st *blkif) -{ - union blkif_back_rings *blk_rings = &blkif->blk_rings; - struct blkif_request req; - struct pending_req *pending_req; - RING_IDX rc, rp; - int more_to_do = 0; - - rc = blk_rings->common.req_cons; - rp = blk_rings->common.sring->req_prod; - rmb(); /* Ensure we see queued requests up to 'rp'. */ - - while (rc != rp) { - - if (RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rc)) - break; - - if (kthread_should_stop()) { - more_to_do = 1; - break; - } - - pending_req = alloc_req(); - if (NULL == pending_req) { - blkif->st_oo_req++; - more_to_do = 1; - break; - } - - switch (blkif->blk_protocol) { - case BLKIF_PROTOCOL_NATIVE: - memcpy(&req, RING_GET_REQUEST(&blk_rings->native, rc), sizeof(req)); - break; - case BLKIF_PROTOCOL_X86_32: - blkif_get_x86_32_req(&req, RING_GET_REQUEST(&blk_rings->x86_32, rc)); - break; - case BLKIF_PROTOCOL_X86_64: - blkif_get_x86_64_req(&req, RING_GET_REQUEST(&blk_rings->x86_64, rc)); - break; - default: - BUG(); - } - blk_rings->common.req_cons = ++rc; /* before make_response() */ - - /* Apply all sanity checks to /private copy/ of request. */ - barrier(); - - switch (req.operation) { - case BLKIF_OP_READ: - blkif->st_rd_req++; - dispatch_rw_block_io(blkif, &req, pending_req); - break; - case BLKIF_OP_WRITE_BARRIER: - blkif->st_br_req++; - /* fall through */ - case BLKIF_OP_WRITE: - blkif->st_wr_req++; - dispatch_rw_block_io(blkif, &req, pending_req); - break; - default: - /* A good sign something is wrong: sleep for a while to - * avoid excessive CPU consumption by a bad guest. */ - msleep(1); - DPRINTK("error: unknown block io operation [%d]\n", - req.operation); - make_response(blkif, req.id, req.operation, - BLKIF_RSP_ERROR); - free_req(pending_req); - break; - } - - /* Yield point for this unbounded loop. */ - cond_resched(); - } - - return more_to_do; -} - -/* - * Transumation of the 'struct blkif_request' to a proper 'struct bio' - * and call the 'submit_bio' to pass it to the underlaying storage. - */ -static void dispatch_rw_block_io(struct blkif_st *blkif, - struct blkif_request *req, - struct pending_req *pending_req) -{ - struct phys_req preq; - struct seg_buf seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - unsigned int nseg; - struct bio *bio = NULL; - struct bio *biolist[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - int i, nbio = 0; - int operation; - struct blk_plug plug; - - switch (req->operation) { - case BLKIF_OP_READ: - operation = READ; - break; - case BLKIF_OP_WRITE: - operation = WRITE; - break; - case BLKIF_OP_WRITE_BARRIER: - operation = WRITE_BARRIER; - break; - default: - operation = 0; /* make gcc happy */ - BUG(); - } - - /* Check that the number of segments is sane. */ - nseg = req->nr_segments; - if (unlikely(nseg == 0 && operation != WRITE_BARRIER) || - unlikely(nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) { - DPRINTK("Bad number of segments in request (%d)\n", nseg); - /* Haven't submitted any bio's yet. */ - goto fail_response; - } - - preq.dev = req->handle; - preq.sector_number = req->u.rw.sector_number; - preq.nr_sects = 0; - - pending_req->blkif = blkif; - pending_req->id = req->id; - pending_req->operation = req->operation; - pending_req->status = BLKIF_RSP_OKAY; - pending_req->nr_pages = nseg; - - for (i = 0; i < nseg; i++) { - seg[i].nsec = req->u.rw.seg[i].last_sect - - req->u.rw.seg[i].first_sect + 1; - if ((req->u.rw.seg[i].last_sect >= (PAGE_SIZE >> 9)) || - (req->u.rw.seg[i].last_sect < req->u.rw.seg[i].first_sect)) - goto fail_response; - preq.nr_sects += seg[i].nsec; - - } - - if (vbd_translate(&preq, blkif, operation) != 0) { - DPRINTK("access denied: %s of [%llu,%llu] on dev=%04x\n", - operation == READ ? "read" : "write", - preq.sector_number, - preq.sector_number + preq.nr_sects, preq.dev); - goto fail_response; - } - /* This check _MUST_ be done after vbd_translate as the preq.bdev - * is set there. */ - for (i = 0; i < nseg; i++) { - if (((int)preq.sector_number|(int)seg[i].nsec) & - ((bdev_logical_block_size(preq.bdev) >> 9) - 1)) { - DPRINTK("Misaligned I/O request from domain %d", - blkif->domid); - goto fail_response; - } - } - /* If we have failed at this point, we need to undo the M2P override, - * set gnttab_set_unmap_op on all of the grant references and perform - * the hypercall to unmap the grants - that is all done in - * xen_blkbk_unmap. - */ - if (xen_blkbk_map(req, pending_req, seg)) - goto fail_flush; - - /* This corresponding blkif_put is done in __end_block_io_op */ - blkif_get(blkif); - - for (i = 0; i < nseg; i++) { - while ((bio == NULL) || - (bio_add_page(bio, - blkbk->pending_page(pending_req, i), - seg[i].nsec << 9, - seg[i].buf & ~PAGE_MASK) == 0)) { - - bio = biolist[nbio++] = bio_alloc(GFP_KERNEL, nseg-i); - if (unlikely(bio == NULL)) - goto fail_put_bio; - - bio->bi_bdev = preq.bdev; - bio->bi_private = pending_req; - bio->bi_end_io = end_block_io_op; - bio->bi_sector = preq.sector_number; - } - - preq.sector_number += seg[i].nsec; - } - - /* This will be hit if the operation was a barrier. */ - if (!bio) { - BUG_ON(operation != WRITE_BARRIER); - bio = biolist[nbio++] = bio_alloc(GFP_KERNEL, 0); - if (unlikely(bio == NULL)) - goto fail_put_bio; - - bio->bi_bdev = preq.bdev; - bio->bi_private = pending_req; - bio->bi_end_io = end_block_io_op; - bio->bi_sector = -1; - } - - - /* We set it one so that the last submit_bio does not have to call - * atomic_inc. - */ - atomic_set(&pending_req->pendcnt, nbio); - - /* Get a reference count for the disk queue and start sending I/O */ - blk_start_plug(&plug); - - for (i = 0; i < nbio; i++) - submit_bio(operation, biolist[i]); - - blk_finish_plug(&plug); - /* Let the I/Os go.. */ - - if (operation == READ) - blkif->st_rd_sect += preq.nr_sects; - else if (operation == WRITE || operation == WRITE_BARRIER) - blkif->st_wr_sect += preq.nr_sects; - - return; - - fail_flush: - xen_blkbk_unmap(pending_req); - fail_response: - /* Haven't submitted any bio's yet. */ - make_response(blkif, req->id, req->operation, BLKIF_RSP_ERROR); - free_req(pending_req); - msleep(1); /* back off a bit */ - return; - - fail_put_bio: - for (i = 0; i < (nbio-1); i++) - bio_put(biolist[i]); - __end_block_io_op(pending_req, -EINVAL); - msleep(1); /* back off a bit */ - return; -} - - - -/* - * Put a response on the ring on how the operation fared. - */ -static void make_response(struct blkif_st *blkif, u64 id, - unsigned short op, int st) -{ - struct blkif_response resp; - unsigned long flags; - union blkif_back_rings *blk_rings = &blkif->blk_rings; - int more_to_do = 0; - int notify; - - resp.id = id; - resp.operation = op; - resp.status = st; - - spin_lock_irqsave(&blkif->blk_ring_lock, flags); - /* Place on the response ring for the relevant domain. */ - switch (blkif->blk_protocol) { - case BLKIF_PROTOCOL_NATIVE: - memcpy(RING_GET_RESPONSE(&blk_rings->native, blk_rings->native.rsp_prod_pvt), - &resp, sizeof(resp)); - break; - case BLKIF_PROTOCOL_X86_32: - memcpy(RING_GET_RESPONSE(&blk_rings->x86_32, blk_rings->x86_32.rsp_prod_pvt), - &resp, sizeof(resp)); - break; - case BLKIF_PROTOCOL_X86_64: - memcpy(RING_GET_RESPONSE(&blk_rings->x86_64, blk_rings->x86_64.rsp_prod_pvt), - &resp, sizeof(resp)); - break; - default: - BUG(); - } - blk_rings->common.rsp_prod_pvt++; - RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blk_rings->common, notify); - if (blk_rings->common.rsp_prod_pvt == blk_rings->common.req_cons) { - /* - * Tail check for pending requests. Allows frontend to avoid - * notifications if requests are already in flight (lower - * overheads and promotes batching). - */ - RING_FINAL_CHECK_FOR_REQUESTS(&blk_rings->common, more_to_do); - - } else if (RING_HAS_UNCONSUMED_REQUESTS(&blk_rings->common)) { - more_to_do = 1; - } - - spin_unlock_irqrestore(&blkif->blk_ring_lock, flags); - - if (more_to_do) - blkif_notify_work(blkif); - if (notify) - notify_remote_via_irq(blkif->irq); -} - -static int __init blkif_init(void) -{ - int i, mmap_pages; - int rc = 0; - - if (!xen_pv_domain()) - return -ENODEV; - - blkbk = kzalloc(sizeof(struct xen_blkbk), GFP_KERNEL); - if (!blkbk) { - printk(KERN_ALERT "%s: out of memory!\n", __func__); - return -ENOMEM; - } - - mmap_pages = blkif_reqs * BLKIF_MAX_SEGMENTS_PER_REQUEST; - - blkbk->pending_reqs = kmalloc(sizeof(blkbk->pending_reqs[0]) * - blkif_reqs, GFP_KERNEL); - blkbk->pending_grant_handles = kzalloc(sizeof(blkbk->pending_grant_handles[0]) * - mmap_pages, GFP_KERNEL); - blkbk->pending_pages = kzalloc(sizeof(blkbk->pending_pages[0]) * - mmap_pages, GFP_KERNEL); - - if (!blkbk->pending_reqs || !blkbk->pending_grant_handles || - !blkbk->pending_pages) { - rc = -ENOMEM; - goto out_of_memory; - } - - for (i = 0; i < mmap_pages; i++) { - blkbk->pending_grant_handles[i] = BLKBACK_INVALID_HANDLE; - blkbk->pending_pages[i] = alloc_page(GFP_KERNEL); - if (blkbk->pending_pages[i] == NULL) { - rc = -ENOMEM; - goto out_of_memory; - } - } - rc = blkif_interface_init(); - if (rc) - goto failed_init; - - memset(blkbk->pending_reqs, 0, sizeof(blkbk->pending_reqs)); - - INIT_LIST_HEAD(&blkbk->pending_free); - spin_lock_init(&blkbk->pending_free_lock); - init_waitqueue_head(&blkbk->pending_free_wq); - - for (i = 0; i < blkif_reqs; i++) - list_add_tail(&blkbk->pending_reqs[i].free_list, - &blkbk->pending_free); - - rc = blkif_xenbus_init(); - if (rc) - goto failed_init; - - return 0; - - out_of_memory: - printk(KERN_ERR "%s: out of memory\n", __func__); - failed_init: - kfree(blkbk->pending_reqs); - kfree(blkbk->pending_grant_handles); - for (i = 0; i < mmap_pages; i++) { - if (blkbk->pending_pages[i]) - __free_page(blkbk->pending_pages[i]); - } - kfree(blkbk->pending_pages); - kfree(blkbk); - blkbk = NULL; - return rc; -} - -module_init(blkif_init); - -MODULE_LICENSE("Dual BSD/GPL"); diff --git a/drivers/xen/blkback/common.h b/drivers/xen/blkback/common.h deleted file mode 100644 index 6257c110659..00000000000 --- a/drivers/xen/blkback/common.h +++ /dev/null @@ -1,142 +0,0 @@ -/* - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation; or, when distributed - * separately from the Linux kernel or incorporated into other - * software packages, subject to the following license: - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this source file (the "Software"), to deal in the Software without - * restriction, including without limitation the rights to use, copy, modify, - * merge, publish, distribute, sublicense, and/or sell copies of the Software, - * and to permit persons to whom the Software is furnished to do so, subject to - * the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS - * IN THE SOFTWARE. - */ - -#ifndef __BLKIF__BACKEND__COMMON_H__ -#define __BLKIF__BACKEND__COMMON_H__ - -#include <linux/version.h> -#include <linux/module.h> -#include <linux/interrupt.h> -#include <linux/slab.h> -#include <linux/blkdev.h> -#include <linux/vmalloc.h> -#include <linux/wait.h> -#include <linux/io.h> -#include <asm/setup.h> -#include <asm/pgalloc.h> -#include <asm/hypervisor.h> -#include <xen/blkif.h> -#include <xen/grant_table.h> -#include <xen/xenbus.h> - -#define DPRINTK(_f, _a...) \ - pr_debug("(file=%s, line=%d) " _f, \ - __FILE__ , __LINE__ , ## _a) - -struct vbd { - blkif_vdev_t handle; /* what the domain refers to this vbd as */ - unsigned char readonly; /* Non-zero -> read-only */ - unsigned char type; /* VDISK_xxx */ - u32 pdevice; /* phys device that this vbd maps to */ - struct block_device *bdev; - sector_t size; /* Cached size parameter */ -}; - -struct backend_info; - -struct blkif_st { - /* Unique identifier for this interface. */ - domid_t domid; - unsigned int handle; - /* Physical parameters of the comms window. */ - unsigned int irq; - /* Comms information. */ - enum blkif_protocol blk_protocol; - union blkif_back_rings blk_rings; - struct vm_struct *blk_ring_area; - /* The VBD attached to this interface. */ - struct vbd vbd; - /* Back pointer to the backend_info. */ - struct backend_info *be; - /* Private fields. */ - spinlock_t blk_ring_lock; - atomic_t refcnt; - - wait_queue_head_t wq; - /* One thread per one blkif. */ - struct task_struct *xenblkd; - unsigned int waiting_reqs; - - /* statistics */ - unsigned long st_print; - int st_rd_req; - int st_wr_req; - int st_oo_req; - int st_br_req; - int st_rd_sect; - int st_wr_sect; - - wait_queue_head_t waiting_to_free; - - grant_handle_t shmem_handle; - grant_ref_t shmem_ref; -}; - -struct blkif_st *blkif_alloc(domid_t domid); -void blkif_disconnect(struct blkif_st *blkif); -void blkif_free(struct blkif_st *blkif); -int blkif_map(struct blkif_st *blkif, unsigned long shared_page, - unsigned int evtchn); -void vbd_resize(struct blkif_st *blkif); - -#define blkif_get(_b) (atomic_inc(&(_b)->refcnt)) -#define blkif_put(_b) \ - do { \ - if (atomic_dec_and_test(&(_b)->refcnt)) \ - wake_up(&(_b)->waiting_to_free);\ - } while (0) - -/* Create a vbd. */ -int vbd_create(struct blkif_st *blkif, blkif_vdev_t vdevice, unsigned major, - unsigned minor, int readonly, int cdrom); -void vbd_free(struct vbd *vbd); - -unsigned long long vbd_size(struct vbd *vbd); -unsigned int vbd_info(struct vbd *vbd); -unsigned long vbd_secsize(struct vbd *vbd); - -struct phys_req { - unsigned short dev; - unsigned short nr_sects; - struct block_device *bdev; - blkif_sector_t sector_number; -}; - -int vbd_translate(struct phys_req *req, struct blkif_st *blkif, int operation); - -int blkif_interface_init(void); - -int blkif_xenbus_init(void); - -irqreturn_t blkif_be_int(int irq, void *dev_id); -int blkif_schedule(void *arg); - -int blkback_barrier(struct xenbus_transaction xbt, - struct backend_info *be, int state); - -struct xenbus_device *blkback_xenbus(struct backend_info *be); - -#endif /* __BLKIF__BACKEND__COMMON_H__ */ diff --git a/drivers/xen/blkback/interface.c b/drivers/xen/blkback/interface.c deleted file mode 100644 index 163aed41e82..00000000000 --- a/drivers/xen/blkback/interface.c +++ /dev/null @@ -1,185 +0,0 @@ -/****************************************************************************** - * Block-device interface management. - * - * Copyright (c) 2004, Keir Fraser - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation; or, when distributed - * separately from the Linux kernel or incorporated into other - * software packages, subject to the following license: - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this source file (the "Software"), to deal in the Software without - * restriction, including without limitation the rights to use, copy, modify, - * merge, publish, distribute, sublicense, and/or sell copies of the Software, - * and to permit persons to whom the Software is furnished to do so, subject to - * the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS - * IN THE SOFTWARE. - */ - -#include "common.h" -#include <xen/events.h> -#include <xen/grant_table.h> -#include <linux/kthread.h> - -static struct kmem_cache *blkif_cachep; - -struct blkif_st *blkif_alloc(domid_t domid) -{ - struct blkif_st *blkif; - - blkif = kmem_cache_alloc(blkif_cachep, GFP_KERNEL); - if (!blkif) - return ERR_PTR(-ENOMEM); - - memset(blkif, 0, sizeof(*blkif)); - blkif->domid = domid; - spin_lock_init(&blkif->blk_ring_lock); - atomic_set(&blkif->refcnt, 1); - init_waitqueue_head(&blkif->wq); - blkif->st_print = jiffies; - init_waitqueue_head(&blkif->waiting_to_free); - - return blkif; -} - -static int map_frontend_page(struct blkif_st *blkif, unsigned long shared_page) -{ - struct gnttab_map_grant_ref op; - - gnttab_set_map_op(&op, (unsigned long)blkif->blk_ring_area->addr, - GNTMAP_host_map, shared_page, blkif->domid); - - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1)) - BUG(); - - if (op.status) { - DPRINTK(" Grant table operation failure !\n"); - return op.status; - } - - blkif->shmem_ref = shared_page; - blkif->shmem_handle = op.handle; - - return 0; -} - -static void unmap_frontend_page(struct blkif_st *blkif) -{ - struct gnttab_unmap_grant_ref op; - - gnttab_set_unmap_op(&op, (unsigned long)blkif->blk_ring_area->addr, - GNTMAP_host_map, blkif->shmem_handle); - - if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1)) - BUG(); -} - -int blkif_map(struct blkif_st *blkif, unsigned long shared_page, - unsigned int evtchn) -{ - int err; - - /* Already connected through? */ - if (blkif->irq) - return 0; - - blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE); - if (!blkif->blk_ring_area) - return -ENOMEM; - - err = map_frontend_page(blkif, shared_page); - if (err) { - free_vm_area(blkif->blk_ring_area); - return err; - } - - switch (blkif->blk_protocol) { - case BLKIF_PROTOCOL_NATIVE: - { - struct blkif_sring *sring; - sring = (struct blkif_sring *)blkif->blk_ring_area->addr; - BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE); - break; - } - case BLKIF_PROTOCOL_X86_32: - { - struct blkif_x86_32_sring *sring_x86_32; - sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring_area->addr; - BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE); - break; - } - case BLKIF_PROTOCOL_X86_64: - { - struct blkif_x86_64_sring *sring_x86_64; - sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring_area->addr; - BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE); - break; - } - default: - BUG(); - } - - err = bind_interdomain_evtchn_to_irqhandler( - blkif->domid, evtchn, blkif_be_int, 0, "blkif-backend", blkif); - if (err < 0) { - unmap_frontend_page(blkif); - free_vm_area(blkif->blk_ring_area); - blkif->blk_rings.common.sring = NULL; - return err; - } - blkif->irq = err; - - return 0; -} - -void blkif_disconnect(struct blkif_st *blkif) -{ - if (blkif->xenblkd) { - kthread_stop(blkif->xenblkd); - blkif->xenblkd = NULL; - } - - atomic_dec(&blkif->refcnt); - wait_event(blkif->waiting_to_free, atomic_read(&blkif->refcnt) == 0); - atomic_inc(&blkif->refcnt); - - if (blkif->irq) { - unbind_from_irqhandler(blkif->irq, blkif); - blkif->irq = 0; - } - - if (blkif->blk_rings.common.sring) { - unmap_frontend_page(blkif); - free_vm_area(blkif->blk_ring_area); - blkif->blk_rings.common.sring = NULL; - } -} - -void blkif_free(struct blkif_st *blkif) -{ - if (!atomic_dec_and_test(&blkif->refcnt)) - BUG(); - kmem_cache_free(blkif_cachep, blkif); -} - -int __init blkif_interface_init(void) -{ - blkif_cachep = kmem_cache_create("blkif_cache", sizeof(struct blkif_st), - 0, 0, NULL); - if (!blkif_cachep) - return -ENOMEM; - - return 0; -} diff --git a/drivers/xen/blkback/vbd.c b/drivers/xen/blkback/vbd.c deleted file mode 100644 index d0ff4cf91a3..00000000000 --- a/drivers/xen/blkback/vbd.c +++ /dev/null @@ -1,162 +0,0 @@ -/****************************************************************************** - * Routines for managing virtual block devices (VBDs). - * - * Copyright (c) 2003-2005, Keir Fraser & Steve Hand - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation; or, when distributed - * separately from the Linux kernel or incorporated into other - * software packages, subject to the following license: - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this source file (the "Software"), to deal in the Software without - * restriction, including without limitation the rights to use, copy, modify, - * merge, publish, distribute, sublicense, and/or sell copies of the Software, - * and to permit persons to whom the Software is furnished to do so, subject to - * the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS - * IN THE SOFTWARE. - */ - -#include "common.h" - -#define vbd_sz(_v) ((_v)->bdev->bd_part ? \ - (_v)->bdev->bd_part->nr_sects : \ - get_capacity((_v)->bdev->bd_disk)) - -unsigned long long vbd_size(struct vbd *vbd) -{ - return vbd_sz(vbd); -} - -unsigned int vbd_info(struct vbd *vbd) -{ - return vbd->type | (vbd->readonly ? VDISK_READONLY : 0); -} - -unsigned long vbd_secsize(struct vbd *vbd) -{ - return bdev_logical_block_size(vbd->bdev); -} - -int vbd_create(struct blkif_st *blkif, blkif_vdev_t handle, unsigned major, - unsigned minor, int readonly, int cdrom) -{ - struct vbd *vbd; - struct block_device *bdev; - - vbd = &blkif->vbd; - vbd->handle = handle; - vbd->readonly = readonly; - vbd->type = 0; - - vbd->pdevice = MKDEV(major, minor); - - bdev = blkdev_get_by_dev(vbd->pdevice, vbd->readonly ? - FMODE_READ : FMODE_WRITE, NULL); - - if (IS_ERR(bdev)) { - DPRINTK("vbd_creat: device %08x could not be opened.\n", - vbd->pdevice); - return -ENOENT; - } - - vbd->bdev = bdev; - vbd->size = vbd_size(vbd); - - if (vbd->bdev->bd_disk == NULL) { - DPRINTK("vbd_creat: device %08x doesn't exist.\n", - vbd->pdevice); - vbd_free(vbd); - return -ENOENT; - } - - if (vbd->bdev->bd_disk->flags & GENHD_FL_CD || cdrom) - vbd->type |= VDISK_CDROM; - if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE) - vbd->type |= VDISK_REMOVABLE; - - DPRINTK("Successful creation of handle=%04x (dom=%u)\n", - handle, blkif->domid); - return 0; -} - -void vbd_free(struct vbd *vbd) -{ - if (vbd->bdev) - blkdev_put(vbd->bdev, vbd->readonly ? FMODE_READ : FMODE_WRITE); - vbd->bdev = NULL; -} - -int vbd_translate(struct phys_req *req, struct blkif_st *blkif, int operation) -{ - struct vbd *vbd = &blkif->vbd; - int rc = -EACCES; - - if ((operation != READ) && vbd->readonly) - goto out; - - if (unlikely((req->sector_number + req->nr_sects) > vbd_sz(vbd))) - goto out; - - req->dev = vbd->pdevice; - req->bdev = vbd->bdev; - rc = 0; - - out: - return rc; -} - -void vbd_resize(struct blkif_st *blkif) -{ - struct vbd *vbd = &blkif->vbd; - struct xenbus_transaction xbt; - int err; - struct xenbus_device *dev = blkback_xenbus(blkif->be); - unsigned long long new_size = vbd_size(vbd); - - printk(KERN_INFO "VBD Resize: Domid: %d, Device: (%d, %d)\n", - blkif->domid, MAJOR(vbd->pdevice), MINOR(vbd->pdevice)); - printk(KERN_INFO "VBD Resize: new size %llu\n", new_size); - vbd->size = new_size; -again: - err = xenbus_transaction_start(&xbt); - if (err) { - printk(KERN_WARNING "Error starting transaction"); - return; - } - err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", - vbd_size(vbd)); - if (err) { - printk(KERN_WARNING "Error writing new size"); - goto abort; - } - /* - * Write the current state; we will use this to synchronize - * the front-end. If the current state is "connected" the - * front-end will get the new size information online. - */ - err = xenbus_printf(xbt, dev->nodename, "state", "%d", dev->state); - if (err) { - printk(KERN_WARNING "Error writing the state"); - goto abort; - } - - err = xenbus_transaction_end(xbt, 0); - if (err == -EAGAIN) - goto again; - if (err) - printk(KERN_WARNING "Error ending transaction"); -abort: - xenbus_transaction_end(xbt, 1); -} diff --git a/drivers/xen/blkback/xenbus.c b/drivers/xen/blkback/xenbus.c deleted file mode 100644 index b41ed65db2d..00000000000 --- a/drivers/xen/blkback/xenbus.c +++ /dev/null @@ -1,562 +0,0 @@ -/* Xenbus code for blkif backend - Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au> - Copyright (C) 2005 XenSource Ltd - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -*/ - -#include <stdarg.h> -#include <linux/module.h> -#include <linux/kthread.h> -#include "common.h" - -#undef DPRINTK -#define DPRINTK(fmt, args...) \ - pr_debug("blkback/xenbus (%s:%d) " fmt ".\n", \ - __func__, __LINE__, ##args) - -struct backend_info { - struct xenbus_device *dev; - struct blkif_st *blkif; - struct xenbus_watch backend_watch; - unsigned major; - unsigned minor; - char *mode; -}; - -static void connect(struct backend_info *); -static int connect_ring(struct backend_info *); -static void backend_changed(struct xenbus_watch *, const char **, - unsigned int); - -struct xenbus_device *blkback_xenbus(struct backend_info *be) -{ - return be->dev; -} - -static int blkback_name(struct blkif_st *blkif, char *buf) -{ - char *devpath, *devname; - struct xenbus_device *dev = blkif->be->dev; - - devpath = xenbus_read(XBT_NIL, dev->nodename, "dev", NULL); - if (IS_ERR(devpath)) - return PTR_ERR(devpath); - - devname = strstr(devpath, "/dev/"); - if (devname != NULL) - devname += strlen("/dev/"); - else - devname = devpath; - - snprintf(buf, TASK_COMM_LEN, "blkback.%d.%s", blkif->domid, devname); - kfree(devpath); - - return 0; -} - -static void update_blkif_status(struct blkif_st *blkif) -{ - int err; - char name[TASK_COMM_LEN]; - - /* Not ready to connect? */ - if (!blkif->irq || !blkif->vbd.bdev) - return; - - /* Already connected? */ - if (blkif->be->dev->state == XenbusStateConnected) - return; - - /* Attempt to connect: exit if we fail to. */ - connect(blkif->be); - if (blkif->be->dev->state != XenbusStateConnected) - return; - - err = blkback_name(blkif, name); - if (err) { - xenbus_dev_error(blkif->be->dev, err, "get blkback dev name"); - return; - } - - err = filemap_write_and_wait(blkif->vbd.bdev->bd_inode->i_mapping); - if (err) { - xenbus_dev_error(blkif->be->dev, err, "block flush"); - return; - } - invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping); - - blkif->xenblkd = kthread_run(blkif_schedule, blkif, name); - if (IS_ERR(blkif->xenblkd)) { - err = PTR_ERR(blkif->xenblkd); - blkif->xenblkd = NULL; - xenbus_dev_error(blkif->be->dev, err, "start xenblkd"); - } -} - - -/* - * sysfs interface for VBD I/O requests - */ - -#define VBD_SHOW(name, format, args...) \ - static ssize_t show_##name(struct device *_dev, \ - struct device_attribute *attr, \ - char *buf) \ - { \ - struct xenbus_device *dev = to_xenbus_device(_dev); \ - struct backend_info *be = dev_get_drvdata(&dev->dev); \ - \ - return sprintf(buf, format, ##args); \ - } \ - static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL) - -VBD_SHOW(oo_req, "%d\n", be->blkif->st_oo_req); -VBD_SHOW(rd_req, "%d\n", be->blkif->st_rd_req); -VBD_SHOW(wr_req, "%d\n", be->blkif->st_wr_req); -VBD_SHOW(br_req, "%d\n", be->blkif->st_br_req); -VBD_SHOW(rd_sect, "%d\n", be->blkif->st_rd_sect); -VBD_SHOW(wr_sect, "%d\n", be->blkif->st_wr_sect); - -static struct attribute *vbdstat_attrs[] = { - &dev_attr_oo_req.attr, - &dev_attr_rd_req.attr, - &dev_attr_wr_req.attr, - &dev_attr_br_req.attr, - &dev_attr_rd_sect.attr, - &dev_attr_wr_sect.attr, - NULL -}; - -static struct attribute_group vbdstat_group = { - .name = "statistics", - .attrs = vbdstat_attrs, -}; - -VBD_SHOW(physical_device, "%x:%x\n", be->major, be->minor); -VBD_SHOW(mode, "%s\n", be->mode); - -int xenvbd_sysfs_addif(struct xenbus_device *dev) -{ - int error; - - error = device_create_file(&dev->dev, &dev_attr_physical_device); - if (error) - goto fail1; - - error = device_create_file(&dev->dev, &dev_attr_mode); - if (error) - goto fail2; - - error = sysfs_create_group(&dev->dev.kobj, &vbdstat_group); - if (error) - goto fail3; - - return 0; - -fail3: sysfs_remove_group(&dev->dev.kobj, &vbdstat_group); -fail2: device_remove_file(&dev->dev, &dev_attr_mode); -fail1: device_remove_file(&dev->dev, &dev_attr_physical_device); - return error; -} - -void xenvbd_sysfs_delif(struct xenbus_device *dev) -{ - sysfs_remove_group(&dev->dev.kobj, &vbdstat_group); - device_remove_file(&dev->dev, &dev_attr_mode); - device_remove_file(&dev->dev, &dev_attr_physical_device); -} - -static int blkback_remove(struct xenbus_device *dev) -{ - struct backend_info *be = dev_get_drvdata(&dev->dev); - - DPRINTK(""); - - if (be->major || be->minor) - xenvbd_sysfs_delif(dev); - - if (be->backend_watch.node) { - unregister_xenbus_watch(&be->backend_watch); - kfree(be->backend_watch.node); - be->backend_watch.node = NULL; - } - - if (be->blkif) { - blkif_disconnect(be->blkif); - vbd_free(&be->blkif->vbd); - blkif_free(be->blkif); - be->blkif = NULL; - } - - kfree(be); - dev_set_drvdata(&dev->dev, NULL); - return 0; -} - -int blkback_barrier(struct xenbus_transaction xbt, - struct backend_info *be, int state) -{ - struct xenbus_device *dev = be->dev; - int err; - - err = xenbus_printf(xbt, dev->nodename, "feature-barrier", - "%d", state); - if (err) - xenbus_dev_fatal(dev, err, "writing feature-barrier"); - - return err; -} - -/** - * Entry point to this code when a new device is created. Allocate the basic - * structures, and watch the store waiting for the hotplug scripts to tell us - * the device's physical major and minor numbers. Switch to InitWait. - */ -static int blkback_probe(struct xenbus_device *dev, - const struct xenbus_device_id *id) -{ - int err; - struct backend_info *be = kzalloc(sizeof(struct backend_info), - GFP_KERNEL); - if (!be) { - xenbus_dev_fatal(dev, -ENOMEM, - "allocating backend structure"); - return -ENOMEM; - } - be->dev = dev; - dev_set_drvdata(&dev->dev, be); - - be->blkif = blkif_alloc(dev->otherend_id); - if (IS_ERR(be->blkif)) { - err = PTR_ERR(be->blkif); - be->blkif = NULL; - xenbus_dev_fatal(dev, err, "creating block interface"); - goto fail; - } - - /* setup back pointer */ - be->blkif->be = be; - - err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, - "%s/%s", dev->nodename, "physical-device"); - if (err) - goto fail; - - err = xenbus_switch_state(dev, XenbusStateInitWait); - if (err) - goto fail; - - return 0; - -fail: - DPRINTK("failed"); - blkback_remove(dev); - return err; -} - - -/** - * Callback received when the hotplug scripts have placed the physical-device - * node. Read it and the mode node, and create a vbd. If the frontend is - * ready, connect. - */ -static void backend_changed(struct xenbus_watch *watch, - const char **vec, unsigned int len) -{ - int err; - unsigned major; - unsigned minor; - struct backend_info *be - = container_of(watch, struct backend_info, backend_watch); - struct xenbus_device *dev = be->dev; - int cdrom = 0; - char *device_type; - - DPRINTK(""); - - err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x", - &major, &minor); - if (XENBUS_EXIST_ERR(err)) { - /* Since this watch will fire once immediately after it is - registered, we expect this. Ignore it, and wait for the - hotplug scripts. */ - return; - } - if (err != 2) { - xenbus_dev_fatal(dev, err, "reading physical-device"); - return; - } - - if ((be->major || be->minor) && - ((be->major != major) || (be->minor != minor))) { - printk(KERN_WARNING - "blkback: changing physical device (from %x:%x to " - "%x:%x) not supported.\n", be->major, be->minor, - major, minor); - return; - } - - be->mode = xenbus_read(XBT_NIL, dev->nodename, "mode", NULL); - if (IS_ERR(be->mode)) { - err = PTR_ERR(be->mode); - be->mode = NULL; - xenbus_dev_fatal(dev, err, "reading mode"); - return; - } - - device_type = xenbus_read(XBT_NIL, dev->otherend, "device-type", NULL); - if (!IS_ERR(device_type)) { - cdrom = strcmp(device_type, "cdrom") == 0; - kfree(device_type); - } - - if (be->major == 0 && be->minor == 0) { - /* Front end dir is a number, which is used as the handle. */ - - char *p = strrchr(dev->otherend, '/') + 1; - long handle; - err = strict_strtoul(p, 0, &handle); - if (err) - return; - - be->major = major; - be->minor = minor; - - err = vbd_create(be->blkif, handle, major, minor, - (NULL == strchr(be->mode, 'w')), cdrom); - if (err) { - be->major = be->minor = 0; - xenbus_dev_fatal(dev, err, "creating vbd structure"); - return; - } - - err = xenvbd_sysfs_addif(dev); - if (err) { - vbd_free(&be->blkif->vbd); - be->major = be->minor = 0; - xenbus_dev_fatal(dev, err, "creating sysfs entries"); - return; - } - - /* We're potentially connected now */ - update_blkif_status(be->blkif); - } -} - - -/** - * Callback received when the frontend's state changes. - */ -static void frontend_changed(struct xenbus_device *dev, - enum xenbus_state frontend_state) -{ - struct backend_info *be = dev_get_drvdata(&dev->dev); - int err; - - DPRINTK("%s", xenbus_strstate(frontend_state)); - - switch (frontend_state) { - case XenbusStateInitialising: - if (dev->state == XenbusStateClosed) { - printk(KERN_INFO "%s: %s: prepare for reconnect\n", - __func__, dev->nodename); - xenbus_switch_state(dev, XenbusStateInitWait); - } - break; - - case XenbusStateInitialised: - case XenbusStateConnected: - /* Ensure we connect even when two watches fire in - close successsion and we miss the intermediate value - of frontend_state. */ - if (dev->state == XenbusStateConnected) - break; - - /* Enforce precondition before potential leak point. - * blkif_disconnect() is idempotent. - */ - blkif_disconnect(be->blkif); - - err = connect_ring(be); - if (err) - break; - update_blkif_status(be->blkif); - break; - - case XenbusStateClosing: - blkif_disconnect(be->blkif); - xenbus_switch_state(dev, XenbusStateClosing); - break; - - case XenbusStateClosed: - xenbus_switch_state(dev, XenbusStateClosed); - if (xenbus_dev_is_online(dev)) - break; - /* fall through if not online */ - case XenbusStateUnknown: - /* implies blkif_disconnect() via blkback_remove() */ - device_unregister(&dev->dev); - break; - - default: - xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", - frontend_state); - break; - } -} - - -/* ** Connection ** */ - - -/** - * Write the physical details regarding the block device to the store, and - * switch to Connected state. - */ -static void connect(struct backend_info *be) -{ - struct xenbus_transaction xbt; - int err; - struct xenbus_device *dev = be->dev; - - DPRINTK("%s", dev->otherend); - - /* Supply the information about the device the frontend needs */ -again: - err = xenbus_transaction_start(&xbt); - if (err) { - xenbus_dev_fatal(dev, err, "starting transaction"); - return; - } - - err = blkback_barrier(xbt, be, 1); - if (err) - goto abort; - - err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", - vbd_size(&be->blkif->vbd)); - if (err) { - xenbus_dev_fatal(dev, err, "writing %s/sectors", - dev->nodename); - goto abort; - } - - /* FIXME: use a typename instead */ - err = xenbus_printf(xbt, dev->nodename, "info", "%u", - vbd_info(&be->blkif->vbd)); - if (err) { - xenbus_dev_fatal(dev, err, "writing %s/info", - dev->nodename); - goto abort; - } - err = xenbus_printf(xbt, dev->nodename, "sector-size", "%lu", - vbd_secsize(&be->blkif->vbd)); - if (err) { - xenbus_dev_fatal(dev, err, "writing %s/sector-size", - dev->nodename); - goto abort; - } - - err = xenbus_transaction_end(xbt, 0); - if (err == -EAGAIN) - goto again; - if (err) - xenbus_dev_fatal(dev, err, "ending transaction"); - - err = xenbus_switch_state(dev, XenbusStateConnected); - if (err) - xenbus_dev_fatal(dev, err, "switching to Connected state", - dev->nodename); - - return; - abort: - xenbus_transaction_end(xbt, 1); -} - - -static int connect_ring(struct backend_info *be) -{ - struct xenbus_device *dev = be->dev; - unsigned long ring_ref; - unsigned int evtchn; - char protocol[64] = ""; - int err; - - DPRINTK("%s", dev->otherend); - - err = xenbus_gather(XBT_NIL, dev->otherend, "ring-ref", "%lu", - &ring_ref, "event-channel", "%u", &evtchn, NULL); - if (err) { - xenbus_dev_fatal(dev, err, - "reading %s/ring-ref and event-channel", - dev->otherend); - return err; - } - - be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; - err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", - "%63s", protocol, NULL); - if (err) - strcpy(protocol, "unspecified, assuming native"); - else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) - be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; - else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) - be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32; - else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64)) - be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64; - else { - xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); - return -1; - } - printk(KERN_INFO - "blkback: ring-ref %ld, event-channel %d, protocol %d (%s)\n", - ring_ref, evtchn, be->blkif->blk_protocol, protocol); - - /* Map the shared frame, irq etc. */ - err = blkif_map(be->blkif, ring_ref, evtchn); - if (err) { - xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u", - ring_ref, evtchn); - return err; - } - - return 0; -} - - -/* ** Driver Registration ** */ - - -static const struct xenbus_device_id blkback_ids[] = { - { "vbd" }, - { "" } -}; - - -static struct xenbus_driver blkback = { - .name = "vbd", - .owner = THIS_MODULE, - .ids = blkback_ids, - .probe = blkback_probe, - .remove = blkback_remove, - .otherend_changed = frontend_changed -}; - - -int blkif_xenbus_init(void) -{ - return xenbus_register_backend(&blkback); -} |