*
* Routines for managing virtual block devices (VBDs).
*
- * NOTE: vbd_lock protects updates to the rb_tree against concurrent lookups
- * in vbd_translate. All other lookups are implicitly protected because the
- * only caller (the control message dispatch routine) serializes the calls.
- *
* 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"
+#include <xen/xenbus.h>
-struct vbd {
- blkif_vdev_t vdevice; /* what the domain refers to this vbd as */
- unsigned char readonly; /* Non-zero -> read-only */
- unsigned char type; /* VDISK_TYPE_xxx */
- blkif_pdev_t pdevice; /* phys device that this vbd maps to */
- struct block_device *bdev;
- rb_node_t rb; /* for linking into R-B tree lookup struct */
-};
+#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
+ (_v)->bdev->bd_part->nr_sects : (_v)->bdev->bd_disk->capacity)
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-static inline dev_t vbd_map_devnum(blkif_pdev_t cookie)
-{ return MKDEV(cookie>>8, cookie&0xff); }
-#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
- (_v)->bdev->bd_part->nr_sects : (_v)->bdev->bd_disk->capacity)
-#define bdev_put(_b) blkdev_put(_b)
-#else
-#define vbd_sz(_v) (blk_size[MAJOR((_v)->pdevice)][MINOR((_v)->pdevice)]*2)
-#define bdev_put(_b) ((void)0)
-#endif
-
-void vbd_create(blkif_be_vbd_create_t *create)
+unsigned long vbd_size(struct vbd *vbd)
{
- struct vbd *vbd;
- rb_node_t **rb_p, *rb_parent = NULL;
- blkif_t *blkif;
- blkif_vdev_t vdevice = create->vdevice;
-
- blkif = blkif_find_by_handle(create->domid, create->blkif_handle);
- if ( unlikely(blkif == NULL) )
- {
- DPRINTK("vbd_create attempted for non-existent blkif (%u,%u)\n",
- create->domid, create->blkif_handle);
- create->status = BLKIF_BE_STATUS_INTERFACE_NOT_FOUND;
- return;
- }
-
- rb_p = &blkif->vbd_rb.rb_node;
- while ( *rb_p != NULL )
- {
- rb_parent = *rb_p;
- vbd = rb_entry(rb_parent, struct vbd, rb);
- if ( vdevice < vbd->vdevice )
- {
- rb_p = &rb_parent->rb_left;
- }
- else if ( vdevice > vbd->vdevice )
- {
- rb_p = &rb_parent->rb_right;
- }
- else
- {
- DPRINTK("vbd_create attempted for already existing vbd\n");
- create->status = BLKIF_BE_STATUS_VBD_EXISTS;
- return;
- }
- }
-
- if ( unlikely((vbd = kmalloc(sizeof(struct vbd), GFP_KERNEL)) == NULL) )
- {
- DPRINTK("vbd_create: out of memory\n");
- create->status = BLKIF_BE_STATUS_OUT_OF_MEMORY;
- return;
- }
-
- vbd->vdevice = vdevice;
- vbd->readonly = create->readonly;
- vbd->type = VDISK_TYPE_DISK | VDISK_FLAG_VIRT;
-
- /* Mask to 16-bit for compatibility with old tools */
- vbd->pdevice = create->pdevice & 0xffff;
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
- vbd->bdev = open_by_devnum(
- vbd_map_devnum(vbd->pdevice),
- vbd->readonly ? FMODE_READ : FMODE_WRITE);
- if ( IS_ERR(vbd->bdev) )
- {
- DPRINTK("vbd_creat: device %08x doesn't exist.\n", vbd->pdevice);
- create->status = BLKIF_BE_STATUS_PHYSDEV_NOT_FOUND;
- return;
- }
-
- if ( (vbd->bdev->bd_disk == NULL) )
- {
- DPRINTK("vbd_creat: device %08x doesn't exist.\n", vbd->pdevice);
- create->status = BLKIF_BE_STATUS_PHYSDEV_NOT_FOUND;
- bdev_put(vbd->bdev);
- return;
- }
-#else
- if ( (blk_size[MAJOR(vbd->pdevice)] == NULL) || (vbd_sz(vbd) == 0) )
- {
- DPRINTK("vbd_creat: device %08x doesn't exist.\n", vbd->pdevice);
- create->status = BLKIF_BE_STATUS_PHYSDEV_NOT_FOUND;
- return;
- }
-#endif
-
- spin_lock(&blkif->vbd_lock);
- rb_link_node(&vbd->rb, rb_parent, rb_p);
- rb_insert_color(&vbd->rb, &blkif->vbd_rb);
- spin_unlock(&blkif->vbd_lock);
-
- DPRINTK("Successful creation of vdev=%04x (dom=%u)\n",
- vdevice, create->domid);
- create->status = BLKIF_BE_STATUS_OKAY;
+ return vbd_sz(vbd);
}
-
-void vbd_destroy(blkif_be_vbd_destroy_t *destroy)
+unsigned int vbd_info(struct vbd *vbd)
{
- blkif_t *blkif;
- struct vbd *vbd;
- rb_node_t *rb;
- blkif_vdev_t vdevice = destroy->vdevice;
-
- blkif = blkif_find_by_handle(destroy->domid, destroy->blkif_handle);
- if ( unlikely(blkif == NULL) )
- {
- DPRINTK("vbd_destroy attempted for non-existent blkif (%u,%u)\n",
- destroy->domid, destroy->blkif_handle);
- destroy->status = BLKIF_BE_STATUS_INTERFACE_NOT_FOUND;
- return;
- }
-
- rb = blkif->vbd_rb.rb_node;
- while ( rb != NULL )
- {
- vbd = rb_entry(rb, struct vbd, rb);
- if ( vdevice < vbd->vdevice )
- rb = rb->rb_left;
- else if ( vdevice > vbd->vdevice )
- rb = rb->rb_right;
- else
- goto found;
- }
-
- destroy->status = BLKIF_BE_STATUS_VBD_NOT_FOUND;
- return;
-
- found:
- spin_lock(&blkif->vbd_lock);
- rb_erase(rb, &blkif->vbd_rb);
- spin_unlock(&blkif->vbd_lock);
- bdev_put(vbd->bdev);
- kfree(vbd);
+ return vbd->type | (vbd->readonly?VDISK_READONLY:0);
}
-
-void destroy_all_vbds(blkif_t *blkif)
+unsigned long vbd_secsize(struct vbd *vbd)
{
- struct vbd *vbd;
- rb_node_t *rb;
-
- spin_lock(&blkif->vbd_lock);
-
- while ( (rb = blkif->vbd_rb.rb_node) != NULL )
- {
- vbd = rb_entry(rb, struct vbd, rb);
- rb_erase(rb, &blkif->vbd_rb);
- spin_unlock(&blkif->vbd_lock);
- bdev_put(vbd->bdev);
- kfree(vbd);
- spin_lock(&blkif->vbd_lock);
- }
-
- spin_unlock(&blkif->vbd_lock);
+ return bdev_hardsect_size(vbd->bdev);
}
-
-static void vbd_probe_single(
- blkif_t *blkif, vdisk_t *vbd_info, struct vbd *vbd)
+int vbd_create(blkif_t *blkif, blkif_vdev_t handle, unsigned major,
+ unsigned minor, int readonly)
{
- vbd_info->device = vbd->vdevice;
- vbd_info->info = vbd->type | (vbd->readonly ? VDISK_FLAG_RO : 0);
- vbd_info->capacity = vbd_sz(vbd);
+ 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 = open_by_devnum(vbd->pdevice,
+ vbd->readonly ? FMODE_READ : FMODE_WRITE);
+
+ if (IS_ERR(bdev)) {
+ DPRINTK("vbd_creat: device %08x could not be opened.\n",
+ vbd->pdevice);
+ return -ENOENT;
+ }
+
+ vbd->bdev = bdev;
+
+ 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)
+ 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;
}
-
-int vbd_probe(blkif_t *blkif, vdisk_t *vbd_info, int max_vbds)
+void vbd_free(struct vbd *vbd)
{
- int rc = 0, nr_vbds = 0;
- rb_node_t *rb;
-
- spin_lock(&blkif->vbd_lock);
-
- if ( (rb = blkif->vbd_rb.rb_node) == NULL )
- goto out;
-
- new_subtree:
- /* STEP 1. Find least node (it'll be left-most). */
- while ( rb->rb_left != NULL )
- rb = rb->rb_left;
-
- for ( ; ; )
- {
- /* STEP 2. Dealt with left subtree. Now process current node. */
- vbd_probe_single(blkif, &vbd_info[nr_vbds],
- rb_entry(rb, struct vbd, rb));
- if ( ++nr_vbds == max_vbds )
- goto out;
-
- /* STEP 3. Process right subtree, if any. */
- if ( rb->rb_right != NULL )
- {
- rb = rb->rb_right;
- goto new_subtree;
- }
-
- /* STEP 4. Done both subtrees. Head back through ancesstors. */
- for ( ; ; )
- {
- /* We're done when we get back to the root node. */
- if ( rb->rb_parent == NULL )
- goto out;
- /* If we are left of parent, then parent is next to process. */
- if ( rb->rb_parent->rb_left == rb )
- break;
- /* If we are right of parent, then we climb to grandparent. */
- rb = rb->rb_parent;
- }
-
- rb = rb->rb_parent;
- }
-
- out:
- spin_unlock(&blkif->vbd_lock);
- return (rc == 0) ? nr_vbds : rc;
+ if (vbd->bdev)
+ blkdev_put(vbd->bdev);
+ vbd->bdev = NULL;
}
-
int vbd_translate(struct phys_req *req, blkif_t *blkif, int operation)
{
- struct vbd *vbd;
- rb_node_t *rb;
- int rc = -EACCES;
-
- /* Take the vbd_lock because another thread could be updating the tree. */
- spin_lock(&blkif->vbd_lock);
-
- rb = blkif->vbd_rb.rb_node;
- while ( rb != NULL )
- {
- vbd = rb_entry(rb, struct vbd, rb);
- if ( req->dev < vbd->vdevice )
- rb = rb->rb_left;
- else if ( req->dev > vbd->vdevice )
- rb = rb->rb_right;
- else
- goto found;
- }
-
- DPRINTK("vbd_translate; domain %u attempted to access "
- "non-existent VBD.\n", blkif->domid);
- rc = -ENODEV;
- goto out;
-
- found:
+ struct vbd *vbd = &blkif->vbd;
+ int rc = -EACCES;
- if ( (operation == WRITE) && vbd->readonly )
- goto out;
+ if ((operation == WRITE) && vbd->readonly)
+ goto out;
- if ( unlikely((req->sector_number + req->nr_sects) > vbd_sz(vbd)) )
- 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;
+ req->dev = vbd->pdevice;
+ req->bdev = vbd->bdev;
+ rc = 0;
out:
- spin_unlock(&blkif->vbd_lock);
- return rc;
+ return rc;
}
git://git.onelab.eu / linux-2.6.git / blobdiff