qed: Table, L2 cache, and cluster functions
This patch adds code to look up data cluster offsets in the image via the L1/L2 tables. The L2 tables are writethrough cached in memory for performance (each read/write requires a lookup so it is essential to cache the tables). With cluster lookup code in place it is possible to implement bdrv_is_allocated() to query the number of contiguous allocated/unallocated clusters. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi
Kevin Wolf
parent
75411d236d
commit
298800cae7
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@ -20,7 +20,7 @@ block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
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block-nested-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat.o
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block-nested-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o
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block-nested-y += qed.o
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block-nested-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
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block-nested-y += parallels.o nbd.o blkdebug.o sheepdog.o blkverify.o
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block-nested-$(CONFIG_WIN32) += raw-win32.o
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block-nested-$(CONFIG_POSIX) += raw-posix.o
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@ -0,0 +1,154 @@
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/*
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* QEMU Enhanced Disk Format Cluster functions
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*
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* Copyright IBM, Corp. 2010
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*
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* Authors:
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* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2 or later.
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* See the COPYING.LIB file in the top-level directory.
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*
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*/
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#include "qed.h"
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/**
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* Count the number of contiguous data clusters
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*
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* @s: QED state
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* @table: L2 table
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* @index: First cluster index
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* @n: Maximum number of clusters
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* @offset: Set to first cluster offset
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*
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* This function scans tables for contiguous allocated or free clusters.
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*/
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static unsigned int qed_count_contiguous_clusters(BDRVQEDState *s,
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QEDTable *table,
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unsigned int index,
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unsigned int n,
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uint64_t *offset)
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{
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unsigned int end = MIN(index + n, s->table_nelems);
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uint64_t last = table->offsets[index];
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unsigned int i;
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*offset = last;
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for (i = index + 1; i < end; i++) {
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if (last == 0) {
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/* Counting free clusters */
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if (table->offsets[i] != 0) {
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break;
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}
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} else {
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/* Counting allocated clusters */
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if (table->offsets[i] != last + s->header.cluster_size) {
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break;
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}
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last = table->offsets[i];
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}
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}
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return i - index;
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}
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typedef struct {
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BDRVQEDState *s;
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uint64_t pos;
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size_t len;
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QEDRequest *request;
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/* User callback */
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QEDFindClusterFunc *cb;
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void *opaque;
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} QEDFindClusterCB;
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static void qed_find_cluster_cb(void *opaque, int ret)
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{
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QEDFindClusterCB *find_cluster_cb = opaque;
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BDRVQEDState *s = find_cluster_cb->s;
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QEDRequest *request = find_cluster_cb->request;
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uint64_t offset = 0;
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size_t len = 0;
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unsigned int index;
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unsigned int n;
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if (ret) {
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goto out;
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}
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index = qed_l2_index(s, find_cluster_cb->pos);
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n = qed_bytes_to_clusters(s,
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qed_offset_into_cluster(s, find_cluster_cb->pos) +
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find_cluster_cb->len);
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n = qed_count_contiguous_clusters(s, request->l2_table->table,
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index, n, &offset);
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ret = offset ? QED_CLUSTER_FOUND : QED_CLUSTER_L2;
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len = MIN(find_cluster_cb->len, n * s->header.cluster_size -
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qed_offset_into_cluster(s, find_cluster_cb->pos));
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if (offset && !qed_check_cluster_offset(s, offset)) {
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ret = -EINVAL;
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}
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out:
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find_cluster_cb->cb(find_cluster_cb->opaque, ret, offset, len);
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qemu_free(find_cluster_cb);
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}
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/**
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* Find the offset of a data cluster
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*
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* @s: QED state
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* @request: L2 cache entry
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* @pos: Byte position in device
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* @len: Number of bytes
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* @cb: Completion function
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* @opaque: User data for completion function
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*
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* This function translates a position in the block device to an offset in the
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* image file. It invokes the cb completion callback to report back the
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* translated offset or unallocated range in the image file.
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*
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* If the L2 table exists, request->l2_table points to the L2 table cache entry
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* and the caller must free the reference when they are finished. The cache
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* entry is exposed in this way to avoid callers having to read the L2 table
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* again later during request processing. If request->l2_table is non-NULL it
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* will be unreferenced before taking on the new cache entry.
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*/
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void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos,
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size_t len, QEDFindClusterFunc *cb, void *opaque)
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{
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QEDFindClusterCB *find_cluster_cb;
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uint64_t l2_offset;
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/* Limit length to L2 boundary. Requests are broken up at the L2 boundary
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* so that a request acts on one L2 table at a time.
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*/
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len = MIN(len, (((pos >> s->l1_shift) + 1) << s->l1_shift) - pos);
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l2_offset = s->l1_table->offsets[qed_l1_index(s, pos)];
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if (!l2_offset) {
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cb(opaque, QED_CLUSTER_L1, 0, len);
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return;
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}
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if (!qed_check_table_offset(s, l2_offset)) {
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cb(opaque, -EINVAL, 0, 0);
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return;
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}
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find_cluster_cb = qemu_malloc(sizeof(*find_cluster_cb));
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find_cluster_cb->s = s;
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find_cluster_cb->pos = pos;
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find_cluster_cb->len = len;
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find_cluster_cb->cb = cb;
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find_cluster_cb->opaque = opaque;
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find_cluster_cb->request = request;
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qed_read_l2_table(s, request, l2_offset,
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qed_find_cluster_cb, find_cluster_cb);
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}
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@ -0,0 +1,32 @@
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/*
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* QEMU Enhanced Disk Format
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*
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* Copyright IBM, Corp. 2010
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*
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* Authors:
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* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2 or later.
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* See the COPYING.LIB file in the top-level directory.
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*
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*/
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#include "qed.h"
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void *gencb_alloc(size_t len, BlockDriverCompletionFunc *cb, void *opaque)
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{
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GenericCB *gencb = qemu_malloc(len);
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gencb->cb = cb;
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gencb->opaque = opaque;
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return gencb;
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}
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void gencb_complete(void *opaque, int ret)
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{
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GenericCB *gencb = opaque;
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BlockDriverCompletionFunc *cb = gencb->cb;
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void *user_opaque = gencb->opaque;
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qemu_free(gencb);
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cb(user_opaque, ret);
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}
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@ -0,0 +1,173 @@
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/*
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* QEMU Enhanced Disk Format L2 Cache
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*
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* Copyright IBM, Corp. 2010
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2 or later.
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* See the COPYING.LIB file in the top-level directory.
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*
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*/
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/*
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* L2 table cache usage is as follows:
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*
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* An open image has one L2 table cache that is used to avoid accessing the
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* image file for recently referenced L2 tables.
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*
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* Cluster offset lookup translates the logical offset within the block device
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* to a cluster offset within the image file. This is done by indexing into
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* the L1 and L2 tables which store cluster offsets. It is here where the L2
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* table cache serves up recently referenced L2 tables.
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*
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* If there is a cache miss, that L2 table is read from the image file and
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* committed to the cache. Subsequent accesses to that L2 table will be served
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* from the cache until the table is evicted from the cache.
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*
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* L2 tables are also committed to the cache when new L2 tables are allocated
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* in the image file. Since the L2 table cache is write-through, the new L2
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* table is first written out to the image file and then committed to the
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* cache.
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*
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* Multiple I/O requests may be using an L2 table cache entry at any given
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* time. That means an entry may be in use across several requests and
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* reference counting is needed to free the entry at the correct time. In
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* particular, an entry evicted from the cache will only be freed once all
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* references are dropped.
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*
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* An in-flight I/O request will hold a reference to a L2 table cache entry for
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* the period during which it needs to access the L2 table. This includes
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* cluster offset lookup, L2 table allocation, and L2 table update when a new
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* data cluster has been allocated.
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*
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* An interesting case occurs when two requests need to access an L2 table that
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* is not in the cache. Since the operation to read the table from the image
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* file takes some time to complete, both requests may see a cache miss and
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* start reading the L2 table from the image file. The first to finish will
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* commit its L2 table into the cache. When the second tries to commit its
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* table will be deleted in favor of the existing cache entry.
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*/
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#include "trace.h"
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#include "qed.h"
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/* Each L2 holds 2GB so this let's us fully cache a 100GB disk */
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#define MAX_L2_CACHE_SIZE 50
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/**
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* Initialize the L2 cache
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*/
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void qed_init_l2_cache(L2TableCache *l2_cache)
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{
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QTAILQ_INIT(&l2_cache->entries);
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l2_cache->n_entries = 0;
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}
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/**
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* Free the L2 cache
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*/
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void qed_free_l2_cache(L2TableCache *l2_cache)
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{
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CachedL2Table *entry, *next_entry;
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QTAILQ_FOREACH_SAFE(entry, &l2_cache->entries, node, next_entry) {
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qemu_vfree(entry->table);
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qemu_free(entry);
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}
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}
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/**
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* Allocate an uninitialized entry from the cache
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*
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* The returned entry has a reference count of 1 and is owned by the caller.
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* The caller must allocate the actual table field for this entry and it must
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* be freeable using qemu_vfree().
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*/
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CachedL2Table *qed_alloc_l2_cache_entry(L2TableCache *l2_cache)
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{
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CachedL2Table *entry;
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entry = qemu_mallocz(sizeof(*entry));
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entry->ref++;
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trace_qed_alloc_l2_cache_entry(l2_cache, entry);
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return entry;
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}
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/**
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* Decrease an entry's reference count and free if necessary when the reference
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* count drops to zero.
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*/
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void qed_unref_l2_cache_entry(CachedL2Table *entry)
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{
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if (!entry) {
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return;
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}
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entry->ref--;
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trace_qed_unref_l2_cache_entry(entry, entry->ref);
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if (entry->ref == 0) {
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qemu_vfree(entry->table);
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qemu_free(entry);
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}
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}
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/**
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* Find an entry in the L2 cache. This may return NULL and it's up to the
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* caller to satisfy the cache miss.
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*
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* For a cached entry, this function increases the reference count and returns
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* the entry.
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*/
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CachedL2Table *qed_find_l2_cache_entry(L2TableCache *l2_cache, uint64_t offset)
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{
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CachedL2Table *entry;
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QTAILQ_FOREACH(entry, &l2_cache->entries, node) {
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if (entry->offset == offset) {
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trace_qed_find_l2_cache_entry(l2_cache, entry, offset, entry->ref);
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entry->ref++;
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return entry;
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}
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}
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return NULL;
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}
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/**
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* Commit an L2 cache entry into the cache. This is meant to be used as part of
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* the process to satisfy a cache miss. A caller would allocate an entry which
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* is not actually in the L2 cache and then once the entry was valid and
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* present on disk, the entry can be committed into the cache.
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*
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* Since the cache is write-through, it's important that this function is not
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* called until the entry is present on disk and the L1 has been updated to
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* point to the entry.
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*
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* N.B. This function steals a reference to the l2_table from the caller so the
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* caller must obtain a new reference by issuing a call to
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* qed_find_l2_cache_entry().
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*/
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void qed_commit_l2_cache_entry(L2TableCache *l2_cache, CachedL2Table *l2_table)
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{
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CachedL2Table *entry;
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entry = qed_find_l2_cache_entry(l2_cache, l2_table->offset);
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if (entry) {
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qed_unref_l2_cache_entry(entry);
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qed_unref_l2_cache_entry(l2_table);
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return;
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}
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if (l2_cache->n_entries >= MAX_L2_CACHE_SIZE) {
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entry = QTAILQ_FIRST(&l2_cache->entries);
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QTAILQ_REMOVE(&l2_cache->entries, entry, node);
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l2_cache->n_entries--;
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qed_unref_l2_cache_entry(entry);
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}
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l2_cache->n_entries++;
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QTAILQ_INSERT_TAIL(&l2_cache->entries, l2_table, node);
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}
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@ -0,0 +1,319 @@
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/*
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* QEMU Enhanced Disk Format Table I/O
|
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*
|
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* Copyright IBM, Corp. 2010
|
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*
|
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* Authors:
|
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* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
|
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* Anthony Liguori <aliguori@us.ibm.com>
|
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*
|
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* This work is licensed under the terms of the GNU LGPL, version 2 or later.
|
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* See the COPYING.LIB file in the top-level directory.
|
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*
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*/
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|
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#include "trace.h"
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#include "qemu_socket.h" /* for EINPROGRESS on Windows */
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#include "qed.h"
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typedef struct {
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GenericCB gencb;
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BDRVQEDState *s;
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QEDTable *table;
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|
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struct iovec iov;
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QEMUIOVector qiov;
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} QEDReadTableCB;
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static void qed_read_table_cb(void *opaque, int ret)
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{
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QEDReadTableCB *read_table_cb = opaque;
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QEDTable *table = read_table_cb->table;
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int noffsets = read_table_cb->iov.iov_len / sizeof(uint64_t);
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int i;
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/* Handle I/O error */
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if (ret) {
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goto out;
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}
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/* Byteswap offsets */
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for (i = 0; i < noffsets; i++) {
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table->offsets[i] = le64_to_cpu(table->offsets[i]);
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}
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out:
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/* Completion */
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trace_qed_read_table_cb(read_table_cb->s, read_table_cb->table, ret);
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gencb_complete(&read_table_cb->gencb, ret);
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}
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static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
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BlockDriverCompletionFunc *cb, void *opaque)
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{
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QEDReadTableCB *read_table_cb = gencb_alloc(sizeof(*read_table_cb),
|
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cb, opaque);
|
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QEMUIOVector *qiov = &read_table_cb->qiov;
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BlockDriverAIOCB *aiocb;
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trace_qed_read_table(s, offset, table);
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read_table_cb->s = s;
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read_table_cb->table = table;
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read_table_cb->iov.iov_base = table->offsets,
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read_table_cb->iov.iov_len = s->header.cluster_size * s->header.table_size,
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qemu_iovec_init_external(qiov, &read_table_cb->iov, 1);
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aiocb = bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov,
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read_table_cb->iov.iov_len / BDRV_SECTOR_SIZE,
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qed_read_table_cb, read_table_cb);
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if (!aiocb) {
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qed_read_table_cb(read_table_cb, -EIO);
|
||||
}
|
||||
}
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||||
|
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typedef struct {
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GenericCB gencb;
|
||||
BDRVQEDState *s;
|
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QEDTable *orig_table;
|
||||
QEDTable *table;
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||||
bool flush; /* flush after write? */
|
||||
|
||||
struct iovec iov;
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||||
QEMUIOVector qiov;
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} QEDWriteTableCB;
|
||||
|
||||
static void qed_write_table_cb(void *opaque, int ret)
|
||||
{
|
||||
QEDWriteTableCB *write_table_cb = opaque;
|
||||
|
||||
trace_qed_write_table_cb(write_table_cb->s,
|
||||
write_table_cb->orig_table,
|
||||
write_table_cb->flush,
|
||||
ret);
|
||||
|
||||
if (ret) {
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (write_table_cb->flush) {
|
||||
/* We still need to flush first */
|
||||
write_table_cb->flush = false;
|
||||
bdrv_aio_flush(write_table_cb->s->bs, qed_write_table_cb,
|
||||
write_table_cb);
|
||||
return;
|
||||
}
|
||||
|
||||
out:
|
||||
qemu_vfree(write_table_cb->table);
|
||||
gencb_complete(&write_table_cb->gencb, ret);
|
||||
return;
|
||||
}
|
||||
|
||||
/**
|
||||
* Write out an updated part or all of a table
|
||||
*
|
||||
* @s: QED state
|
||||
* @offset: Offset of table in image file, in bytes
|
||||
* @table: Table
|
||||
* @index: Index of first element
|
||||
* @n: Number of elements
|
||||
* @flush: Whether or not to sync to disk
|
||||
* @cb: Completion function
|
||||
* @opaque: Argument for completion function
|
||||
*/
|
||||
static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
|
||||
unsigned int index, unsigned int n, bool flush,
|
||||
BlockDriverCompletionFunc *cb, void *opaque)
|
||||
{
|
||||
QEDWriteTableCB *write_table_cb;
|
||||
BlockDriverAIOCB *aiocb;
|
||||
unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
|
||||
unsigned int start, end, i;
|
||||
size_t len_bytes;
|
||||
|
||||
trace_qed_write_table(s, offset, table, index, n);
|
||||
|
||||
/* Calculate indices of the first and one after last elements */
|
||||
start = index & ~sector_mask;
|
||||
end = (index + n + sector_mask) & ~sector_mask;
|
||||
|
||||
len_bytes = (end - start) * sizeof(uint64_t);
|
||||
|
||||
write_table_cb = gencb_alloc(sizeof(*write_table_cb), cb, opaque);
|
||||
write_table_cb->s = s;
|
||||
write_table_cb->orig_table = table;
|
||||
write_table_cb->flush = flush;
|
||||
write_table_cb->table = qemu_blockalign(s->bs, len_bytes);
|
||||
write_table_cb->iov.iov_base = write_table_cb->table->offsets;
|
||||
write_table_cb->iov.iov_len = len_bytes;
|
||||
qemu_iovec_init_external(&write_table_cb->qiov, &write_table_cb->iov, 1);
|
||||
|
||||
/* Byteswap table */
|
||||
for (i = start; i < end; i++) {
|
||||
uint64_t le_offset = cpu_to_le64(table->offsets[i]);
|
||||
write_table_cb->table->offsets[i - start] = le_offset;
|
||||
}
|
||||
|
||||
/* Adjust for offset into table */
|
||||
offset += start * sizeof(uint64_t);
|
||||
|
||||
aiocb = bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
|
||||
&write_table_cb->qiov,
|
||||
write_table_cb->iov.iov_len / BDRV_SECTOR_SIZE,
|
||||
qed_write_table_cb, write_table_cb);
|
||||
if (!aiocb) {
|
||||
qed_write_table_cb(write_table_cb, -EIO);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Propagate return value from async callback
|
||||
*/
|
||||
static void qed_sync_cb(void *opaque, int ret)
|
||||
{
|
||||
*(int *)opaque = ret;
|
||||
}
|
||||
|
||||
int qed_read_l1_table_sync(BDRVQEDState *s)
|
||||
{
|
||||
int ret = -EINPROGRESS;
|
||||
|
||||
async_context_push();
|
||||
|
||||
qed_read_table(s, s->header.l1_table_offset,
|
||||
s->l1_table, qed_sync_cb, &ret);
|
||||
while (ret == -EINPROGRESS) {
|
||||
qemu_aio_wait();
|
||||
}
|
||||
|
||||
async_context_pop();
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,
|
||||
BlockDriverCompletionFunc *cb, void *opaque)
|
||||
{
|
||||
BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE);
|
||||
qed_write_table(s, s->header.l1_table_offset,
|
||||
s->l1_table, index, n, false, cb, opaque);
|
||||
}
|
||||
|
||||
int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
|
||||
unsigned int n)
|
||||
{
|
||||
int ret = -EINPROGRESS;
|
||||
|
||||
async_context_push();
|
||||
|
||||
qed_write_l1_table(s, index, n, qed_sync_cb, &ret);
|
||||
while (ret == -EINPROGRESS) {
|
||||
qemu_aio_wait();
|
||||
}
|
||||
|
||||
async_context_pop();
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
typedef struct {
|
||||
GenericCB gencb;
|
||||
BDRVQEDState *s;
|
||||
uint64_t l2_offset;
|
||||
QEDRequest *request;
|
||||
} QEDReadL2TableCB;
|
||||
|
||||
static void qed_read_l2_table_cb(void *opaque, int ret)
|
||||
{
|
||||
QEDReadL2TableCB *read_l2_table_cb = opaque;
|
||||
QEDRequest *request = read_l2_table_cb->request;
|
||||
BDRVQEDState *s = read_l2_table_cb->s;
|
||||
CachedL2Table *l2_table = request->l2_table;
|
||||
|
||||
if (ret) {
|
||||
/* can't trust loaded L2 table anymore */
|
||||
qed_unref_l2_cache_entry(l2_table);
|
||||
request->l2_table = NULL;
|
||||
} else {
|
||||
l2_table->offset = read_l2_table_cb->l2_offset;
|
||||
|
||||
qed_commit_l2_cache_entry(&s->l2_cache, l2_table);
|
||||
|
||||
/* This is guaranteed to succeed because we just committed the entry
|
||||
* to the cache.
|
||||
*/
|
||||
request->l2_table = qed_find_l2_cache_entry(&s->l2_cache,
|
||||
l2_table->offset);
|
||||
assert(request->l2_table != NULL);
|
||||
}
|
||||
|
||||
gencb_complete(&read_l2_table_cb->gencb, ret);
|
||||
}
|
||||
|
||||
void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
|
||||
BlockDriverCompletionFunc *cb, void *opaque)
|
||||
{
|
||||
QEDReadL2TableCB *read_l2_table_cb;
|
||||
|
||||
qed_unref_l2_cache_entry(request->l2_table);
|
||||
|
||||
/* Check for cached L2 entry */
|
||||
request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset);
|
||||
if (request->l2_table) {
|
||||
cb(opaque, 0);
|
||||
return;
|
||||
}
|
||||
|
||||
request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
|
||||
request->l2_table->table = qed_alloc_table(s);
|
||||
|
||||
read_l2_table_cb = gencb_alloc(sizeof(*read_l2_table_cb), cb, opaque);
|
||||
read_l2_table_cb->s = s;
|
||||
read_l2_table_cb->l2_offset = offset;
|
||||
read_l2_table_cb->request = request;
|
||||
|
||||
BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD);
|
||||
qed_read_table(s, offset, request->l2_table->table,
|
||||
qed_read_l2_table_cb, read_l2_table_cb);
|
||||
}
|
||||
|
||||
int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset)
|
||||
{
|
||||
int ret = -EINPROGRESS;
|
||||
|
||||
async_context_push();
|
||||
|
||||
qed_read_l2_table(s, request, offset, qed_sync_cb, &ret);
|
||||
while (ret == -EINPROGRESS) {
|
||||
qemu_aio_wait();
|
||||
}
|
||||
|
||||
async_context_pop();
|
||||
return ret;
|
||||
}
|
||||
|
||||
void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
|
||||
unsigned int index, unsigned int n, bool flush,
|
||||
BlockDriverCompletionFunc *cb, void *opaque)
|
||||
{
|
||||
BLKDBG_EVENT(s->bs->file, BLKDBG_L2_UPDATE);
|
||||
qed_write_table(s, request->l2_table->offset,
|
||||
request->l2_table->table, index, n, flush, cb, opaque);
|
||||
}
|
||||
|
||||
int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
|
||||
unsigned int index, unsigned int n, bool flush)
|
||||
{
|
||||
int ret = -EINPROGRESS;
|
||||
|
||||
async_context_push();
|
||||
|
||||
qed_write_l2_table(s, request, index, n, flush, qed_sync_cb, &ret);
|
||||
while (ret == -EINPROGRESS) {
|
||||
qemu_aio_wait();
|
||||
}
|
||||
|
||||
async_context_pop();
|
||||
return ret;
|
||||
}
|
||||
54
block/qed.c
54
block/qed.c
|
|
@ -155,6 +155,13 @@ static int qed_read_string(BlockDriverState *file, uint64_t offset, size_t n,
|
|||
return 0;
|
||||
}
|
||||
|
||||
QEDTable *qed_alloc_table(BDRVQEDState *s)
|
||||
{
|
||||
/* Honor O_DIRECT memory alignment requirements */
|
||||
return qemu_blockalign(s->bs,
|
||||
s->header.cluster_size * s->header.table_size);
|
||||
}
|
||||
|
||||
static int bdrv_qed_open(BlockDriverState *bs, int flags)
|
||||
{
|
||||
BDRVQEDState *s = bs->opaque;
|
||||
|
|
@ -244,11 +251,23 @@ static int bdrv_qed_open(BlockDriverState *bs, int flags)
|
|||
bdrv_flush(bs->file);
|
||||
}
|
||||
|
||||
s->l1_table = qed_alloc_table(s);
|
||||
qed_init_l2_cache(&s->l2_cache);
|
||||
|
||||
ret = qed_read_l1_table_sync(s);
|
||||
if (ret) {
|
||||
qed_free_l2_cache(&s->l2_cache);
|
||||
qemu_vfree(s->l1_table);
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void bdrv_qed_close(BlockDriverState *bs)
|
||||
{
|
||||
BDRVQEDState *s = bs->opaque;
|
||||
|
||||
qed_free_l2_cache(&s->l2_cache);
|
||||
qemu_vfree(s->l1_table);
|
||||
}
|
||||
|
||||
static int bdrv_qed_flush(BlockDriverState *bs)
|
||||
|
|
@ -368,10 +387,43 @@ static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options)
|
|||
backing_file, backing_fmt);
|
||||
}
|
||||
|
||||
typedef struct {
|
||||
int is_allocated;
|
||||
int *pnum;
|
||||
} QEDIsAllocatedCB;
|
||||
|
||||
static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t len)
|
||||
{
|
||||
QEDIsAllocatedCB *cb = opaque;
|
||||
*cb->pnum = len / BDRV_SECTOR_SIZE;
|
||||
cb->is_allocated = ret == QED_CLUSTER_FOUND;
|
||||
}
|
||||
|
||||
static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
||||
int nb_sectors, int *pnum)
|
||||
{
|
||||
return -ENOTSUP;
|
||||
BDRVQEDState *s = bs->opaque;
|
||||
uint64_t pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE;
|
||||
size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE;
|
||||
QEDIsAllocatedCB cb = {
|
||||
.is_allocated = -1,
|
||||
.pnum = pnum,
|
||||
};
|
||||
QEDRequest request = { .l2_table = NULL };
|
||||
|
||||
async_context_push();
|
||||
|
||||
qed_find_cluster(s, &request, pos, len, qed_is_allocated_cb, &cb);
|
||||
|
||||
while (cb.is_allocated == -1) {
|
||||
qemu_aio_wait();
|
||||
}
|
||||
|
||||
async_context_pop();
|
||||
|
||||
qed_unref_l2_cache_entry(request.l2_table);
|
||||
|
||||
return cb.is_allocated;
|
||||
}
|
||||
|
||||
static int bdrv_qed_make_empty(BlockDriverState *bs)
|
||||
|
|
|
|||
123
block/qed.h
123
block/qed.h
|
|
@ -95,17 +95,119 @@ typedef struct {
|
|||
uint32_t backing_filename_size; /* in bytes */
|
||||
} QEDHeader;
|
||||
|
||||
typedef struct {
|
||||
uint64_t offsets[0]; /* in bytes */
|
||||
} QEDTable;
|
||||
|
||||
/* The L2 cache is a simple write-through cache for L2 structures */
|
||||
typedef struct CachedL2Table {
|
||||
QEDTable *table;
|
||||
uint64_t offset; /* offset=0 indicates an invalidate entry */
|
||||
QTAILQ_ENTRY(CachedL2Table) node;
|
||||
int ref;
|
||||
} CachedL2Table;
|
||||
|
||||
typedef struct {
|
||||
QTAILQ_HEAD(, CachedL2Table) entries;
|
||||
unsigned int n_entries;
|
||||
} L2TableCache;
|
||||
|
||||
typedef struct QEDRequest {
|
||||
CachedL2Table *l2_table;
|
||||
} QEDRequest;
|
||||
|
||||
typedef struct {
|
||||
BlockDriverState *bs; /* device */
|
||||
uint64_t file_size; /* length of image file, in bytes */
|
||||
|
||||
QEDHeader header; /* always cpu-endian */
|
||||
QEDTable *l1_table;
|
||||
L2TableCache l2_cache; /* l2 table cache */
|
||||
uint32_t table_nelems;
|
||||
uint32_t l1_shift;
|
||||
uint32_t l2_shift;
|
||||
uint32_t l2_mask;
|
||||
} BDRVQEDState;
|
||||
|
||||
enum {
|
||||
QED_CLUSTER_FOUND, /* cluster found */
|
||||
QED_CLUSTER_L2, /* cluster missing in L2 */
|
||||
QED_CLUSTER_L1, /* cluster missing in L1 */
|
||||
};
|
||||
|
||||
/**
|
||||
* qed_find_cluster() completion callback
|
||||
*
|
||||
* @opaque: User data for completion callback
|
||||
* @ret: QED_CLUSTER_FOUND Success
|
||||
* QED_CLUSTER_L2 Data cluster unallocated in L2
|
||||
* QED_CLUSTER_L1 L2 unallocated in L1
|
||||
* -errno POSIX error occurred
|
||||
* @offset: Data cluster offset
|
||||
* @len: Contiguous bytes starting from cluster offset
|
||||
*
|
||||
* This function is invoked when qed_find_cluster() completes.
|
||||
*
|
||||
* On success ret is QED_CLUSTER_FOUND and offset/len are a contiguous range
|
||||
* in the image file.
|
||||
*
|
||||
* On failure ret is QED_CLUSTER_L2 or QED_CLUSTER_L1 for missing L2 or L1
|
||||
* table offset, respectively. len is number of contiguous unallocated bytes.
|
||||
*/
|
||||
typedef void QEDFindClusterFunc(void *opaque, int ret, uint64_t offset, size_t len);
|
||||
|
||||
/**
|
||||
* Generic callback for chaining async callbacks
|
||||
*/
|
||||
typedef struct {
|
||||
BlockDriverCompletionFunc *cb;
|
||||
void *opaque;
|
||||
} GenericCB;
|
||||
|
||||
void *gencb_alloc(size_t len, BlockDriverCompletionFunc *cb, void *opaque);
|
||||
void gencb_complete(void *opaque, int ret);
|
||||
|
||||
/**
|
||||
* L2 cache functions
|
||||
*/
|
||||
void qed_init_l2_cache(L2TableCache *l2_cache);
|
||||
void qed_free_l2_cache(L2TableCache *l2_cache);
|
||||
CachedL2Table *qed_alloc_l2_cache_entry(L2TableCache *l2_cache);
|
||||
void qed_unref_l2_cache_entry(CachedL2Table *entry);
|
||||
CachedL2Table *qed_find_l2_cache_entry(L2TableCache *l2_cache, uint64_t offset);
|
||||
void qed_commit_l2_cache_entry(L2TableCache *l2_cache, CachedL2Table *l2_table);
|
||||
|
||||
/**
|
||||
* Table I/O functions
|
||||
*/
|
||||
int qed_read_l1_table_sync(BDRVQEDState *s);
|
||||
void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,
|
||||
BlockDriverCompletionFunc *cb, void *opaque);
|
||||
int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
|
||||
unsigned int n);
|
||||
int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
|
||||
uint64_t offset);
|
||||
void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
|
||||
BlockDriverCompletionFunc *cb, void *opaque);
|
||||
void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
|
||||
unsigned int index, unsigned int n, bool flush,
|
||||
BlockDriverCompletionFunc *cb, void *opaque);
|
||||
int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
|
||||
unsigned int index, unsigned int n, bool flush);
|
||||
|
||||
/**
|
||||
* Cluster functions
|
||||
*/
|
||||
void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos,
|
||||
size_t len, QEDFindClusterFunc *cb, void *opaque);
|
||||
|
||||
/**
|
||||
* Consistency check
|
||||
*/
|
||||
int qed_check(BDRVQEDState *s, BdrvCheckResult *result, bool fix);
|
||||
|
||||
QEDTable *qed_alloc_table(BDRVQEDState *s);
|
||||
|
||||
/**
|
||||
* Round down to the start of a cluster
|
||||
*/
|
||||
|
|
@ -114,6 +216,27 @@ static inline uint64_t qed_start_of_cluster(BDRVQEDState *s, uint64_t offset)
|
|||
return offset & ~(uint64_t)(s->header.cluster_size - 1);
|
||||
}
|
||||
|
||||
static inline uint64_t qed_offset_into_cluster(BDRVQEDState *s, uint64_t offset)
|
||||
{
|
||||
return offset & (s->header.cluster_size - 1);
|
||||
}
|
||||
|
||||
static inline unsigned int qed_bytes_to_clusters(BDRVQEDState *s, size_t bytes)
|
||||
{
|
||||
return qed_start_of_cluster(s, bytes + (s->header.cluster_size - 1)) /
|
||||
(s->header.cluster_size - 1);
|
||||
}
|
||||
|
||||
static inline unsigned int qed_l1_index(BDRVQEDState *s, uint64_t pos)
|
||||
{
|
||||
return pos >> s->l1_shift;
|
||||
}
|
||||
|
||||
static inline unsigned int qed_l2_index(BDRVQEDState *s, uint64_t pos)
|
||||
{
|
||||
return (pos >> s->l2_shift) & s->l2_mask;
|
||||
}
|
||||
|
||||
/**
|
||||
* Test if a cluster offset is valid
|
||||
*/
|
||||
|
|
|
|||
11
trace-events
11
trace-events
|
|
@ -192,3 +192,14 @@ disable sun4m_iommu_bad_addr(uint64_t addr) "bad addr %"PRIx64""
|
|||
|
||||
# vl.c
|
||||
disable vm_state_notify(int running, int reason) "running %d reason %d"
|
||||
|
||||
# block/qed-l2-cache.c
|
||||
disable qed_alloc_l2_cache_entry(void *l2_cache, void *entry) "l2_cache %p entry %p"
|
||||
disable qed_unref_l2_cache_entry(void *entry, int ref) "entry %p ref %d"
|
||||
disable qed_find_l2_cache_entry(void *l2_cache, void *entry, uint64_t offset, int ref) "l2_cache %p entry %p offset %"PRIu64" ref %d"
|
||||
|
||||
# block/qed-table.c
|
||||
disable qed_read_table(void *s, uint64_t offset, void *table) "s %p offset %"PRIu64" table %p"
|
||||
disable qed_read_table_cb(void *s, void *table, int ret) "s %p table %p ret %d"
|
||||
disable qed_write_table(void *s, uint64_t offset, void *table, unsigned int index, unsigned int n) "s %p offset %"PRIu64" table %p index %u n %u"
|
||||
disable qed_write_table_cb(void *s, void *table, int flush, int ret) "s %p table %p flush %d ret %d"
|
||||
|
|
|
|||
Reference in New Issue