diff options
Diffstat (limited to 'drivers/xen/blkback/blkback.c')
| -rw-r--r-- | drivers/xen/blkback/blkback.c | 759 |
1 files changed, 0 insertions, 759 deletions
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"); |