The purpose of AsyncContexts was to protect qcow and qcow2 against reentrancy during an emulated bdrv_read/write (which includes a qemu_aio_wait() call and can run AIO callbacks of different requests if it weren't for AsyncContexts). Now both qcow and qcow2 are protected by CoMutexes and AsyncContexts can be removed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
1501 lines
43 KiB
C
1501 lines
43 KiB
C
/*
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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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* 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 "qemu-timer.h"
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#include "trace.h"
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#include "qed.h"
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#include "qerror.h"
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static void qed_aio_cancel(BlockDriverAIOCB *blockacb)
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{
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QEDAIOCB *acb = (QEDAIOCB *)blockacb;
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bool finished = false;
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/* Wait for the request to finish */
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acb->finished = &finished;
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while (!finished) {
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qemu_aio_wait();
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}
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}
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static AIOPool qed_aio_pool = {
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.aiocb_size = sizeof(QEDAIOCB),
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.cancel = qed_aio_cancel,
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};
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static int bdrv_qed_probe(const uint8_t *buf, int buf_size,
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const char *filename)
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{
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const QEDHeader *header = (const QEDHeader *)buf;
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if (buf_size < sizeof(*header)) {
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return 0;
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}
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if (le32_to_cpu(header->magic) != QED_MAGIC) {
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return 0;
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}
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return 100;
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}
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/**
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* Check whether an image format is raw
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*
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* @fmt: Backing file format, may be NULL
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*/
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static bool qed_fmt_is_raw(const char *fmt)
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{
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return fmt && strcmp(fmt, "raw") == 0;
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}
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static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu)
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{
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cpu->magic = le32_to_cpu(le->magic);
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cpu->cluster_size = le32_to_cpu(le->cluster_size);
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cpu->table_size = le32_to_cpu(le->table_size);
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cpu->header_size = le32_to_cpu(le->header_size);
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cpu->features = le64_to_cpu(le->features);
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cpu->compat_features = le64_to_cpu(le->compat_features);
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cpu->autoclear_features = le64_to_cpu(le->autoclear_features);
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cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset);
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cpu->image_size = le64_to_cpu(le->image_size);
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cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset);
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cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size);
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}
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static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le)
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{
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le->magic = cpu_to_le32(cpu->magic);
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le->cluster_size = cpu_to_le32(cpu->cluster_size);
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le->table_size = cpu_to_le32(cpu->table_size);
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le->header_size = cpu_to_le32(cpu->header_size);
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le->features = cpu_to_le64(cpu->features);
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le->compat_features = cpu_to_le64(cpu->compat_features);
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le->autoclear_features = cpu_to_le64(cpu->autoclear_features);
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le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset);
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le->image_size = cpu_to_le64(cpu->image_size);
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le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset);
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le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size);
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}
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static int qed_write_header_sync(BDRVQEDState *s)
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{
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QEDHeader le;
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int ret;
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qed_header_cpu_to_le(&s->header, &le);
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ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le));
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if (ret != sizeof(le)) {
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return ret;
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}
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return 0;
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}
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typedef struct {
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GenericCB gencb;
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BDRVQEDState *s;
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struct iovec iov;
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QEMUIOVector qiov;
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int nsectors;
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uint8_t *buf;
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} QEDWriteHeaderCB;
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static void qed_write_header_cb(void *opaque, int ret)
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{
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QEDWriteHeaderCB *write_header_cb = opaque;
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qemu_vfree(write_header_cb->buf);
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gencb_complete(write_header_cb, ret);
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}
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static void qed_write_header_read_cb(void *opaque, int ret)
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{
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QEDWriteHeaderCB *write_header_cb = opaque;
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BDRVQEDState *s = write_header_cb->s;
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BlockDriverAIOCB *acb;
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if (ret) {
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qed_write_header_cb(write_header_cb, ret);
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return;
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}
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/* Update header */
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qed_header_cpu_to_le(&s->header, (QEDHeader *)write_header_cb->buf);
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acb = bdrv_aio_writev(s->bs->file, 0, &write_header_cb->qiov,
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write_header_cb->nsectors, qed_write_header_cb,
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write_header_cb);
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if (!acb) {
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qed_write_header_cb(write_header_cb, -EIO);
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}
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}
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/**
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* Update header in-place (does not rewrite backing filename or other strings)
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*
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* This function only updates known header fields in-place and does not affect
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* extra data after the QED header.
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*/
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static void qed_write_header(BDRVQEDState *s, BlockDriverCompletionFunc cb,
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void *opaque)
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{
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/* We must write full sectors for O_DIRECT but cannot necessarily generate
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* the data following the header if an unrecognized compat feature is
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* active. Therefore, first read the sectors containing the header, update
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* them, and write back.
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*/
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BlockDriverAIOCB *acb;
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int nsectors = (sizeof(QEDHeader) + BDRV_SECTOR_SIZE - 1) /
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BDRV_SECTOR_SIZE;
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size_t len = nsectors * BDRV_SECTOR_SIZE;
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QEDWriteHeaderCB *write_header_cb = gencb_alloc(sizeof(*write_header_cb),
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cb, opaque);
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write_header_cb->s = s;
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write_header_cb->nsectors = nsectors;
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write_header_cb->buf = qemu_blockalign(s->bs, len);
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write_header_cb->iov.iov_base = write_header_cb->buf;
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write_header_cb->iov.iov_len = len;
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qemu_iovec_init_external(&write_header_cb->qiov, &write_header_cb->iov, 1);
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acb = bdrv_aio_readv(s->bs->file, 0, &write_header_cb->qiov, nsectors,
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qed_write_header_read_cb, write_header_cb);
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if (!acb) {
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qed_write_header_cb(write_header_cb, -EIO);
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}
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}
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static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size)
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{
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uint64_t table_entries;
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uint64_t l2_size;
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table_entries = (table_size * cluster_size) / sizeof(uint64_t);
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l2_size = table_entries * cluster_size;
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return l2_size * table_entries;
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}
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static bool qed_is_cluster_size_valid(uint32_t cluster_size)
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{
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if (cluster_size < QED_MIN_CLUSTER_SIZE ||
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cluster_size > QED_MAX_CLUSTER_SIZE) {
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return false;
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}
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if (cluster_size & (cluster_size - 1)) {
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return false; /* not power of 2 */
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}
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return true;
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}
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static bool qed_is_table_size_valid(uint32_t table_size)
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{
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if (table_size < QED_MIN_TABLE_SIZE ||
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table_size > QED_MAX_TABLE_SIZE) {
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return false;
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}
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if (table_size & (table_size - 1)) {
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return false; /* not power of 2 */
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}
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return true;
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}
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static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size,
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uint32_t table_size)
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{
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if (image_size % BDRV_SECTOR_SIZE != 0) {
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return false; /* not multiple of sector size */
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}
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if (image_size > qed_max_image_size(cluster_size, table_size)) {
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return false; /* image is too large */
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}
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return true;
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}
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/**
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* Read a string of known length from the image file
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*
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* @file: Image file
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* @offset: File offset to start of string, in bytes
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* @n: String length in bytes
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* @buf: Destination buffer
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* @buflen: Destination buffer length in bytes
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* @ret: 0 on success, -errno on failure
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*
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* The string is NUL-terminated.
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*/
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static int qed_read_string(BlockDriverState *file, uint64_t offset, size_t n,
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char *buf, size_t buflen)
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{
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int ret;
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if (n >= buflen) {
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return -EINVAL;
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}
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ret = bdrv_pread(file, offset, buf, n);
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if (ret < 0) {
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return ret;
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}
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buf[n] = '\0';
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return 0;
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}
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/**
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* Allocate new clusters
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*
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* @s: QED state
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* @n: Number of contiguous clusters to allocate
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* @ret: Offset of first allocated cluster
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*
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* This function only produces the offset where the new clusters should be
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* written. It updates BDRVQEDState but does not make any changes to the image
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* file.
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*/
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static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n)
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{
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uint64_t offset = s->file_size;
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s->file_size += n * s->header.cluster_size;
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return offset;
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}
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QEDTable *qed_alloc_table(BDRVQEDState *s)
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{
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/* Honor O_DIRECT memory alignment requirements */
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return qemu_blockalign(s->bs,
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s->header.cluster_size * s->header.table_size);
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}
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/**
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* Allocate a new zeroed L2 table
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*/
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static CachedL2Table *qed_new_l2_table(BDRVQEDState *s)
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{
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CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
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l2_table->table = qed_alloc_table(s);
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l2_table->offset = qed_alloc_clusters(s, s->header.table_size);
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memset(l2_table->table->offsets, 0,
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s->header.cluster_size * s->header.table_size);
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return l2_table;
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}
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static void qed_aio_next_io(void *opaque, int ret);
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|
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static void qed_plug_allocating_write_reqs(BDRVQEDState *s)
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{
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assert(!s->allocating_write_reqs_plugged);
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s->allocating_write_reqs_plugged = true;
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}
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|
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static void qed_unplug_allocating_write_reqs(BDRVQEDState *s)
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{
|
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QEDAIOCB *acb;
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|
|
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assert(s->allocating_write_reqs_plugged);
|
|
|
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s->allocating_write_reqs_plugged = false;
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|
|
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acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs);
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if (acb) {
|
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qed_aio_next_io(acb, 0);
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}
|
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}
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|
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static void qed_finish_clear_need_check(void *opaque, int ret)
|
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{
|
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/* Do nothing */
|
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}
|
|
|
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static void qed_flush_after_clear_need_check(void *opaque, int ret)
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{
|
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BDRVQEDState *s = opaque;
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|
|
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bdrv_aio_flush(s->bs, qed_finish_clear_need_check, s);
|
|
|
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/* No need to wait until flush completes */
|
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qed_unplug_allocating_write_reqs(s);
|
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}
|
|
|
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static void qed_clear_need_check(void *opaque, int ret)
|
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{
|
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BDRVQEDState *s = opaque;
|
|
|
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if (ret) {
|
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qed_unplug_allocating_write_reqs(s);
|
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return;
|
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}
|
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|
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s->header.features &= ~QED_F_NEED_CHECK;
|
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qed_write_header(s, qed_flush_after_clear_need_check, s);
|
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}
|
|
|
|
static void qed_need_check_timer_cb(void *opaque)
|
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{
|
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BDRVQEDState *s = opaque;
|
|
|
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/* The timer should only fire when allocating writes have drained */
|
|
assert(!QSIMPLEQ_FIRST(&s->allocating_write_reqs));
|
|
|
|
trace_qed_need_check_timer_cb(s);
|
|
|
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qed_plug_allocating_write_reqs(s);
|
|
|
|
/* Ensure writes are on disk before clearing flag */
|
|
bdrv_aio_flush(s->bs, qed_clear_need_check, s);
|
|
}
|
|
|
|
static void qed_start_need_check_timer(BDRVQEDState *s)
|
|
{
|
|
trace_qed_start_need_check_timer(s);
|
|
|
|
/* Use vm_clock so we don't alter the image file while suspended for
|
|
* migration.
|
|
*/
|
|
qemu_mod_timer(s->need_check_timer, qemu_get_clock_ns(vm_clock) +
|
|
get_ticks_per_sec() * QED_NEED_CHECK_TIMEOUT);
|
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}
|
|
|
|
/* It's okay to call this multiple times or when no timer is started */
|
|
static void qed_cancel_need_check_timer(BDRVQEDState *s)
|
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{
|
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trace_qed_cancel_need_check_timer(s);
|
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qemu_del_timer(s->need_check_timer);
|
|
}
|
|
|
|
static int bdrv_qed_open(BlockDriverState *bs, int flags)
|
|
{
|
|
BDRVQEDState *s = bs->opaque;
|
|
QEDHeader le_header;
|
|
int64_t file_size;
|
|
int ret;
|
|
|
|
s->bs = bs;
|
|
QSIMPLEQ_INIT(&s->allocating_write_reqs);
|
|
|
|
ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header));
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
ret = 0; /* ret should always be 0 or -errno */
|
|
qed_header_le_to_cpu(&le_header, &s->header);
|
|
|
|
if (s->header.magic != QED_MAGIC) {
|
|
return -EINVAL;
|
|
}
|
|
if (s->header.features & ~QED_FEATURE_MASK) {
|
|
/* image uses unsupported feature bits */
|
|
char buf[64];
|
|
snprintf(buf, sizeof(buf), "%" PRIx64,
|
|
s->header.features & ~QED_FEATURE_MASK);
|
|
qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
|
|
bs->device_name, "QED", buf);
|
|
return -ENOTSUP;
|
|
}
|
|
if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Round down file size to the last cluster */
|
|
file_size = bdrv_getlength(bs->file);
|
|
if (file_size < 0) {
|
|
return file_size;
|
|
}
|
|
s->file_size = qed_start_of_cluster(s, file_size);
|
|
|
|
if (!qed_is_table_size_valid(s->header.table_size)) {
|
|
return -EINVAL;
|
|
}
|
|
if (!qed_is_image_size_valid(s->header.image_size,
|
|
s->header.cluster_size,
|
|
s->header.table_size)) {
|
|
return -EINVAL;
|
|
}
|
|
if (!qed_check_table_offset(s, s->header.l1_table_offset)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
s->table_nelems = (s->header.cluster_size * s->header.table_size) /
|
|
sizeof(uint64_t);
|
|
s->l2_shift = ffs(s->header.cluster_size) - 1;
|
|
s->l2_mask = s->table_nelems - 1;
|
|
s->l1_shift = s->l2_shift + ffs(s->table_nelems) - 1;
|
|
|
|
if ((s->header.features & QED_F_BACKING_FILE)) {
|
|
if ((uint64_t)s->header.backing_filename_offset +
|
|
s->header.backing_filename_size >
|
|
s->header.cluster_size * s->header.header_size) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = qed_read_string(bs->file, s->header.backing_filename_offset,
|
|
s->header.backing_filename_size, bs->backing_file,
|
|
sizeof(bs->backing_file));
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) {
|
|
pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw");
|
|
}
|
|
}
|
|
|
|
/* Reset unknown autoclear feature bits. This is a backwards
|
|
* compatibility mechanism that allows images to be opened by older
|
|
* programs, which "knock out" unknown feature bits. When an image is
|
|
* opened by a newer program again it can detect that the autoclear
|
|
* feature is no longer valid.
|
|
*/
|
|
if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 &&
|
|
!bdrv_is_read_only(bs->file)) {
|
|
s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK;
|
|
|
|
ret = qed_write_header_sync(s);
|
|
if (ret) {
|
|
return ret;
|
|
}
|
|
|
|
/* From here on only known autoclear feature bits are valid */
|
|
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) {
|
|
goto out;
|
|
}
|
|
|
|
/* If image was not closed cleanly, check consistency */
|
|
if (s->header.features & QED_F_NEED_CHECK) {
|
|
/* Read-only images cannot be fixed. There is no risk of corruption
|
|
* since write operations are not possible. Therefore, allow
|
|
* potentially inconsistent images to be opened read-only. This can
|
|
* aid data recovery from an otherwise inconsistent image.
|
|
*/
|
|
if (!bdrv_is_read_only(bs->file)) {
|
|
BdrvCheckResult result = {0};
|
|
|
|
ret = qed_check(s, &result, true);
|
|
if (ret) {
|
|
goto out;
|
|
}
|
|
if (!result.corruptions && !result.check_errors) {
|
|
/* Ensure fixes reach storage before clearing check bit */
|
|
bdrv_flush(s->bs);
|
|
|
|
s->header.features &= ~QED_F_NEED_CHECK;
|
|
qed_write_header_sync(s);
|
|
}
|
|
}
|
|
}
|
|
|
|
s->need_check_timer = qemu_new_timer_ns(vm_clock,
|
|
qed_need_check_timer_cb, s);
|
|
|
|
out:
|
|
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_cancel_need_check_timer(s);
|
|
qemu_free_timer(s->need_check_timer);
|
|
|
|
/* Ensure writes reach stable storage */
|
|
bdrv_flush(bs->file);
|
|
|
|
/* Clean shutdown, no check required on next open */
|
|
if (s->header.features & QED_F_NEED_CHECK) {
|
|
s->header.features &= ~QED_F_NEED_CHECK;
|
|
qed_write_header_sync(s);
|
|
}
|
|
|
|
qed_free_l2_cache(&s->l2_cache);
|
|
qemu_vfree(s->l1_table);
|
|
}
|
|
|
|
static int bdrv_qed_flush(BlockDriverState *bs)
|
|
{
|
|
return bdrv_flush(bs->file);
|
|
}
|
|
|
|
static int qed_create(const char *filename, uint32_t cluster_size,
|
|
uint64_t image_size, uint32_t table_size,
|
|
const char *backing_file, const char *backing_fmt)
|
|
{
|
|
QEDHeader header = {
|
|
.magic = QED_MAGIC,
|
|
.cluster_size = cluster_size,
|
|
.table_size = table_size,
|
|
.header_size = 1,
|
|
.features = 0,
|
|
.compat_features = 0,
|
|
.l1_table_offset = cluster_size,
|
|
.image_size = image_size,
|
|
};
|
|
QEDHeader le_header;
|
|
uint8_t *l1_table = NULL;
|
|
size_t l1_size = header.cluster_size * header.table_size;
|
|
int ret = 0;
|
|
BlockDriverState *bs = NULL;
|
|
|
|
ret = bdrv_create_file(filename, NULL);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR | BDRV_O_CACHE_WB);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* File must start empty and grow, check truncate is supported */
|
|
ret = bdrv_truncate(bs, 0);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
if (backing_file) {
|
|
header.features |= QED_F_BACKING_FILE;
|
|
header.backing_filename_offset = sizeof(le_header);
|
|
header.backing_filename_size = strlen(backing_file);
|
|
|
|
if (qed_fmt_is_raw(backing_fmt)) {
|
|
header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
|
|
}
|
|
}
|
|
|
|
qed_header_cpu_to_le(&header, &le_header);
|
|
ret = bdrv_pwrite(bs, 0, &le_header, sizeof(le_header));
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
ret = bdrv_pwrite(bs, sizeof(le_header), backing_file,
|
|
header.backing_filename_size);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
l1_table = qemu_mallocz(l1_size);
|
|
ret = bdrv_pwrite(bs, header.l1_table_offset, l1_table, l1_size);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = 0; /* success */
|
|
out:
|
|
qemu_free(l1_table);
|
|
bdrv_delete(bs);
|
|
return ret;
|
|
}
|
|
|
|
static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options)
|
|
{
|
|
uint64_t image_size = 0;
|
|
uint32_t cluster_size = QED_DEFAULT_CLUSTER_SIZE;
|
|
uint32_t table_size = QED_DEFAULT_TABLE_SIZE;
|
|
const char *backing_file = NULL;
|
|
const char *backing_fmt = NULL;
|
|
|
|
while (options && options->name) {
|
|
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
|
image_size = options->value.n;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
|
|
backing_file = options->value.s;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
|
|
backing_fmt = options->value.s;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
|
|
if (options->value.n) {
|
|
cluster_size = options->value.n;
|
|
}
|
|
} else if (!strcmp(options->name, BLOCK_OPT_TABLE_SIZE)) {
|
|
if (options->value.n) {
|
|
table_size = options->value.n;
|
|
}
|
|
}
|
|
options++;
|
|
}
|
|
|
|
if (!qed_is_cluster_size_valid(cluster_size)) {
|
|
fprintf(stderr, "QED cluster size must be within range [%u, %u] and power of 2\n",
|
|
QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE);
|
|
return -EINVAL;
|
|
}
|
|
if (!qed_is_table_size_valid(table_size)) {
|
|
fprintf(stderr, "QED table size must be within range [%u, %u] and power of 2\n",
|
|
QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE);
|
|
return -EINVAL;
|
|
}
|
|
if (!qed_is_image_size_valid(image_size, cluster_size, table_size)) {
|
|
fprintf(stderr, "QED image size must be a non-zero multiple of "
|
|
"cluster size and less than %" PRIu64 " bytes\n",
|
|
qed_max_image_size(cluster_size, table_size));
|
|
return -EINVAL;
|
|
}
|
|
|
|
return qed_create(filename, cluster_size, image_size, table_size,
|
|
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 || ret == QED_CLUSTER_ZERO);
|
|
}
|
|
|
|
static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
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 };
|
|
|
|
qed_find_cluster(s, &request, pos, len, qed_is_allocated_cb, &cb);
|
|
|
|
while (cb.is_allocated == -1) {
|
|
qemu_aio_wait();
|
|
}
|
|
|
|
qed_unref_l2_cache_entry(request.l2_table);
|
|
|
|
return cb.is_allocated;
|
|
}
|
|
|
|
static int bdrv_qed_make_empty(BlockDriverState *bs)
|
|
{
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
static BDRVQEDState *acb_to_s(QEDAIOCB *acb)
|
|
{
|
|
return acb->common.bs->opaque;
|
|
}
|
|
|
|
/**
|
|
* Read from the backing file or zero-fill if no backing file
|
|
*
|
|
* @s: QED state
|
|
* @pos: Byte position in device
|
|
* @qiov: Destination I/O vector
|
|
* @cb: Completion function
|
|
* @opaque: User data for completion function
|
|
*
|
|
* This function reads qiov->size bytes starting at pos from the backing file.
|
|
* If there is no backing file then zeroes are read.
|
|
*/
|
|
static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos,
|
|
QEMUIOVector *qiov,
|
|
BlockDriverCompletionFunc *cb, void *opaque)
|
|
{
|
|
BlockDriverAIOCB *aiocb;
|
|
uint64_t backing_length = 0;
|
|
size_t size;
|
|
|
|
/* If there is a backing file, get its length. Treat the absence of a
|
|
* backing file like a zero length backing file.
|
|
*/
|
|
if (s->bs->backing_hd) {
|
|
int64_t l = bdrv_getlength(s->bs->backing_hd);
|
|
if (l < 0) {
|
|
cb(opaque, l);
|
|
return;
|
|
}
|
|
backing_length = l;
|
|
}
|
|
|
|
/* Zero all sectors if reading beyond the end of the backing file */
|
|
if (pos >= backing_length ||
|
|
pos + qiov->size > backing_length) {
|
|
qemu_iovec_memset(qiov, 0, qiov->size);
|
|
}
|
|
|
|
/* Complete now if there are no backing file sectors to read */
|
|
if (pos >= backing_length) {
|
|
cb(opaque, 0);
|
|
return;
|
|
}
|
|
|
|
/* If the read straddles the end of the backing file, shorten it */
|
|
size = MIN((uint64_t)backing_length - pos, qiov->size);
|
|
|
|
BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING);
|
|
aiocb = bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE,
|
|
qiov, size / BDRV_SECTOR_SIZE, cb, opaque);
|
|
if (!aiocb) {
|
|
cb(opaque, -EIO);
|
|
}
|
|
}
|
|
|
|
typedef struct {
|
|
GenericCB gencb;
|
|
BDRVQEDState *s;
|
|
QEMUIOVector qiov;
|
|
struct iovec iov;
|
|
uint64_t offset;
|
|
} CopyFromBackingFileCB;
|
|
|
|
static void qed_copy_from_backing_file_cb(void *opaque, int ret)
|
|
{
|
|
CopyFromBackingFileCB *copy_cb = opaque;
|
|
qemu_vfree(copy_cb->iov.iov_base);
|
|
gencb_complete(©_cb->gencb, ret);
|
|
}
|
|
|
|
static void qed_copy_from_backing_file_write(void *opaque, int ret)
|
|
{
|
|
CopyFromBackingFileCB *copy_cb = opaque;
|
|
BDRVQEDState *s = copy_cb->s;
|
|
BlockDriverAIOCB *aiocb;
|
|
|
|
if (ret) {
|
|
qed_copy_from_backing_file_cb(copy_cb, ret);
|
|
return;
|
|
}
|
|
|
|
BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE);
|
|
aiocb = bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE,
|
|
©_cb->qiov,
|
|
copy_cb->qiov.size / BDRV_SECTOR_SIZE,
|
|
qed_copy_from_backing_file_cb, copy_cb);
|
|
if (!aiocb) {
|
|
qed_copy_from_backing_file_cb(copy_cb, -EIO);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Copy data from backing file into the image
|
|
*
|
|
* @s: QED state
|
|
* @pos: Byte position in device
|
|
* @len: Number of bytes
|
|
* @offset: Byte offset in image file
|
|
* @cb: Completion function
|
|
* @opaque: User data for completion function
|
|
*/
|
|
static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos,
|
|
uint64_t len, uint64_t offset,
|
|
BlockDriverCompletionFunc *cb,
|
|
void *opaque)
|
|
{
|
|
CopyFromBackingFileCB *copy_cb;
|
|
|
|
/* Skip copy entirely if there is no work to do */
|
|
if (len == 0) {
|
|
cb(opaque, 0);
|
|
return;
|
|
}
|
|
|
|
copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque);
|
|
copy_cb->s = s;
|
|
copy_cb->offset = offset;
|
|
copy_cb->iov.iov_base = qemu_blockalign(s->bs, len);
|
|
copy_cb->iov.iov_len = len;
|
|
qemu_iovec_init_external(©_cb->qiov, ©_cb->iov, 1);
|
|
|
|
qed_read_backing_file(s, pos, ©_cb->qiov,
|
|
qed_copy_from_backing_file_write, copy_cb);
|
|
}
|
|
|
|
/**
|
|
* Link one or more contiguous clusters into a table
|
|
*
|
|
* @s: QED state
|
|
* @table: L2 table
|
|
* @index: First cluster index
|
|
* @n: Number of contiguous clusters
|
|
* @cluster: First cluster offset
|
|
*
|
|
* The cluster offset may be an allocated byte offset in the image file, the
|
|
* zero cluster marker, or the unallocated cluster marker.
|
|
*/
|
|
static void qed_update_l2_table(BDRVQEDState *s, QEDTable *table, int index,
|
|
unsigned int n, uint64_t cluster)
|
|
{
|
|
int i;
|
|
for (i = index; i < index + n; i++) {
|
|
table->offsets[i] = cluster;
|
|
if (!qed_offset_is_unalloc_cluster(cluster) &&
|
|
!qed_offset_is_zero_cluster(cluster)) {
|
|
cluster += s->header.cluster_size;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void qed_aio_complete_bh(void *opaque)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BlockDriverCompletionFunc *cb = acb->common.cb;
|
|
void *user_opaque = acb->common.opaque;
|
|
int ret = acb->bh_ret;
|
|
bool *finished = acb->finished;
|
|
|
|
qemu_bh_delete(acb->bh);
|
|
qemu_aio_release(acb);
|
|
|
|
/* Invoke callback */
|
|
cb(user_opaque, ret);
|
|
|
|
/* Signal cancel completion */
|
|
if (finished) {
|
|
*finished = true;
|
|
}
|
|
}
|
|
|
|
static void qed_aio_complete(QEDAIOCB *acb, int ret)
|
|
{
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
|
|
trace_qed_aio_complete(s, acb, ret);
|
|
|
|
/* Free resources */
|
|
qemu_iovec_destroy(&acb->cur_qiov);
|
|
qed_unref_l2_cache_entry(acb->request.l2_table);
|
|
|
|
/* Arrange for a bh to invoke the completion function */
|
|
acb->bh_ret = ret;
|
|
acb->bh = qemu_bh_new(qed_aio_complete_bh, acb);
|
|
qemu_bh_schedule(acb->bh);
|
|
|
|
/* Start next allocating write request waiting behind this one. Note that
|
|
* requests enqueue themselves when they first hit an unallocated cluster
|
|
* but they wait until the entire request is finished before waking up the
|
|
* next request in the queue. This ensures that we don't cycle through
|
|
* requests multiple times but rather finish one at a time completely.
|
|
*/
|
|
if (acb == QSIMPLEQ_FIRST(&s->allocating_write_reqs)) {
|
|
QSIMPLEQ_REMOVE_HEAD(&s->allocating_write_reqs, next);
|
|
acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs);
|
|
if (acb) {
|
|
qed_aio_next_io(acb, 0);
|
|
} else if (s->header.features & QED_F_NEED_CHECK) {
|
|
qed_start_need_check_timer(s);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Commit the current L2 table to the cache
|
|
*/
|
|
static void qed_commit_l2_update(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
CachedL2Table *l2_table = acb->request.l2_table;
|
|
|
|
qed_commit_l2_cache_entry(&s->l2_cache, l2_table);
|
|
|
|
/* This is guaranteed to succeed because we just committed the entry to the
|
|
* cache.
|
|
*/
|
|
acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache,
|
|
l2_table->offset);
|
|
assert(acb->request.l2_table != NULL);
|
|
|
|
qed_aio_next_io(opaque, ret);
|
|
}
|
|
|
|
/**
|
|
* Update L1 table with new L2 table offset and write it out
|
|
*/
|
|
static void qed_aio_write_l1_update(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
int index;
|
|
|
|
if (ret) {
|
|
qed_aio_complete(acb, ret);
|
|
return;
|
|
}
|
|
|
|
index = qed_l1_index(s, acb->cur_pos);
|
|
s->l1_table->offsets[index] = acb->request.l2_table->offset;
|
|
|
|
qed_write_l1_table(s, index, 1, qed_commit_l2_update, acb);
|
|
}
|
|
|
|
/**
|
|
* Update L2 table with new cluster offsets and write them out
|
|
*/
|
|
static void qed_aio_write_l2_update(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1;
|
|
int index;
|
|
|
|
if (ret) {
|
|
goto err;
|
|
}
|
|
|
|
if (need_alloc) {
|
|
qed_unref_l2_cache_entry(acb->request.l2_table);
|
|
acb->request.l2_table = qed_new_l2_table(s);
|
|
}
|
|
|
|
index = qed_l2_index(s, acb->cur_pos);
|
|
qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters,
|
|
acb->cur_cluster);
|
|
|
|
if (need_alloc) {
|
|
/* Write out the whole new L2 table */
|
|
qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true,
|
|
qed_aio_write_l1_update, acb);
|
|
} else {
|
|
/* Write out only the updated part of the L2 table */
|
|
qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, false,
|
|
qed_aio_next_io, acb);
|
|
}
|
|
return;
|
|
|
|
err:
|
|
qed_aio_complete(acb, ret);
|
|
}
|
|
|
|
/**
|
|
* Flush new data clusters before updating the L2 table
|
|
*
|
|
* This flush is necessary when a backing file is in use. A crash during an
|
|
* allocating write could result in empty clusters in the image. If the write
|
|
* only touched a subregion of the cluster, then backing image sectors have
|
|
* been lost in the untouched region. The solution is to flush after writing a
|
|
* new data cluster and before updating the L2 table.
|
|
*/
|
|
static void qed_aio_write_flush_before_l2_update(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
|
|
if (!bdrv_aio_flush(s->bs->file, qed_aio_write_l2_update, opaque)) {
|
|
qed_aio_complete(acb, -EIO);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Write data to the image file
|
|
*/
|
|
static void qed_aio_write_main(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
uint64_t offset = acb->cur_cluster +
|
|
qed_offset_into_cluster(s, acb->cur_pos);
|
|
BlockDriverCompletionFunc *next_fn;
|
|
BlockDriverAIOCB *file_acb;
|
|
|
|
trace_qed_aio_write_main(s, acb, ret, offset, acb->cur_qiov.size);
|
|
|
|
if (ret) {
|
|
qed_aio_complete(acb, ret);
|
|
return;
|
|
}
|
|
|
|
if (acb->find_cluster_ret == QED_CLUSTER_FOUND) {
|
|
next_fn = qed_aio_next_io;
|
|
} else {
|
|
if (s->bs->backing_hd) {
|
|
next_fn = qed_aio_write_flush_before_l2_update;
|
|
} else {
|
|
next_fn = qed_aio_write_l2_update;
|
|
}
|
|
}
|
|
|
|
BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO);
|
|
file_acb = bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
|
|
&acb->cur_qiov,
|
|
acb->cur_qiov.size / BDRV_SECTOR_SIZE,
|
|
next_fn, acb);
|
|
if (!file_acb) {
|
|
qed_aio_complete(acb, -EIO);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Populate back untouched region of new data cluster
|
|
*/
|
|
static void qed_aio_write_postfill(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
uint64_t start = acb->cur_pos + acb->cur_qiov.size;
|
|
uint64_t len =
|
|
qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start;
|
|
uint64_t offset = acb->cur_cluster +
|
|
qed_offset_into_cluster(s, acb->cur_pos) +
|
|
acb->cur_qiov.size;
|
|
|
|
if (ret) {
|
|
qed_aio_complete(acb, ret);
|
|
return;
|
|
}
|
|
|
|
trace_qed_aio_write_postfill(s, acb, start, len, offset);
|
|
qed_copy_from_backing_file(s, start, len, offset,
|
|
qed_aio_write_main, acb);
|
|
}
|
|
|
|
/**
|
|
* Populate front untouched region of new data cluster
|
|
*/
|
|
static void qed_aio_write_prefill(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
uint64_t start = qed_start_of_cluster(s, acb->cur_pos);
|
|
uint64_t len = qed_offset_into_cluster(s, acb->cur_pos);
|
|
|
|
trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster);
|
|
qed_copy_from_backing_file(s, start, len, acb->cur_cluster,
|
|
qed_aio_write_postfill, acb);
|
|
}
|
|
|
|
/**
|
|
* Check if the QED_F_NEED_CHECK bit should be set during allocating write
|
|
*/
|
|
static bool qed_should_set_need_check(BDRVQEDState *s)
|
|
{
|
|
/* The flush before L2 update path ensures consistency */
|
|
if (s->bs->backing_hd) {
|
|
return false;
|
|
}
|
|
|
|
return !(s->header.features & QED_F_NEED_CHECK);
|
|
}
|
|
|
|
/**
|
|
* Write new data cluster
|
|
*
|
|
* @acb: Write request
|
|
* @len: Length in bytes
|
|
*
|
|
* This path is taken when writing to previously unallocated clusters.
|
|
*/
|
|
static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len)
|
|
{
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
|
|
/* Cancel timer when the first allocating request comes in */
|
|
if (QSIMPLEQ_EMPTY(&s->allocating_write_reqs)) {
|
|
qed_cancel_need_check_timer(s);
|
|
}
|
|
|
|
/* Freeze this request if another allocating write is in progress */
|
|
if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs)) {
|
|
QSIMPLEQ_INSERT_TAIL(&s->allocating_write_reqs, acb, next);
|
|
}
|
|
if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs) ||
|
|
s->allocating_write_reqs_plugged) {
|
|
return; /* wait for existing request to finish */
|
|
}
|
|
|
|
acb->cur_nclusters = qed_bytes_to_clusters(s,
|
|
qed_offset_into_cluster(s, acb->cur_pos) + len);
|
|
acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters);
|
|
qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
|
|
|
|
if (qed_should_set_need_check(s)) {
|
|
s->header.features |= QED_F_NEED_CHECK;
|
|
qed_write_header(s, qed_aio_write_prefill, acb);
|
|
} else {
|
|
qed_aio_write_prefill(acb, 0);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Write data cluster in place
|
|
*
|
|
* @acb: Write request
|
|
* @offset: Cluster offset in bytes
|
|
* @len: Length in bytes
|
|
*
|
|
* This path is taken when writing to already allocated clusters.
|
|
*/
|
|
static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, size_t len)
|
|
{
|
|
/* Calculate the I/O vector */
|
|
acb->cur_cluster = offset;
|
|
qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
|
|
|
|
/* Do the actual write */
|
|
qed_aio_write_main(acb, 0);
|
|
}
|
|
|
|
/**
|
|
* Write data cluster
|
|
*
|
|
* @opaque: Write request
|
|
* @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
|
|
* or -errno
|
|
* @offset: Cluster offset in bytes
|
|
* @len: Length in bytes
|
|
*
|
|
* Callback from qed_find_cluster().
|
|
*/
|
|
static void qed_aio_write_data(void *opaque, int ret,
|
|
uint64_t offset, size_t len)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
|
|
trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len);
|
|
|
|
acb->find_cluster_ret = ret;
|
|
|
|
switch (ret) {
|
|
case QED_CLUSTER_FOUND:
|
|
qed_aio_write_inplace(acb, offset, len);
|
|
break;
|
|
|
|
case QED_CLUSTER_L2:
|
|
case QED_CLUSTER_L1:
|
|
case QED_CLUSTER_ZERO:
|
|
qed_aio_write_alloc(acb, len);
|
|
break;
|
|
|
|
default:
|
|
qed_aio_complete(acb, ret);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Read data cluster
|
|
*
|
|
* @opaque: Read request
|
|
* @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
|
|
* or -errno
|
|
* @offset: Cluster offset in bytes
|
|
* @len: Length in bytes
|
|
*
|
|
* Callback from qed_find_cluster().
|
|
*/
|
|
static void qed_aio_read_data(void *opaque, int ret,
|
|
uint64_t offset, size_t len)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
BlockDriverState *bs = acb->common.bs;
|
|
BlockDriverAIOCB *file_acb;
|
|
|
|
/* Adjust offset into cluster */
|
|
offset += qed_offset_into_cluster(s, acb->cur_pos);
|
|
|
|
trace_qed_aio_read_data(s, acb, ret, offset, len);
|
|
|
|
if (ret < 0) {
|
|
goto err;
|
|
}
|
|
|
|
qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
|
|
|
|
/* Handle zero cluster and backing file reads */
|
|
if (ret == QED_CLUSTER_ZERO) {
|
|
qemu_iovec_memset(&acb->cur_qiov, 0, acb->cur_qiov.size);
|
|
qed_aio_next_io(acb, 0);
|
|
return;
|
|
} else if (ret != QED_CLUSTER_FOUND) {
|
|
qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov,
|
|
qed_aio_next_io, acb);
|
|
return;
|
|
}
|
|
|
|
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
|
|
file_acb = bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE,
|
|
&acb->cur_qiov,
|
|
acb->cur_qiov.size / BDRV_SECTOR_SIZE,
|
|
qed_aio_next_io, acb);
|
|
if (!file_acb) {
|
|
ret = -EIO;
|
|
goto err;
|
|
}
|
|
return;
|
|
|
|
err:
|
|
qed_aio_complete(acb, ret);
|
|
}
|
|
|
|
/**
|
|
* Begin next I/O or complete the request
|
|
*/
|
|
static void qed_aio_next_io(void *opaque, int ret)
|
|
{
|
|
QEDAIOCB *acb = opaque;
|
|
BDRVQEDState *s = acb_to_s(acb);
|
|
QEDFindClusterFunc *io_fn =
|
|
acb->is_write ? qed_aio_write_data : qed_aio_read_data;
|
|
|
|
trace_qed_aio_next_io(s, acb, ret, acb->cur_pos + acb->cur_qiov.size);
|
|
|
|
/* Handle I/O error */
|
|
if (ret) {
|
|
qed_aio_complete(acb, ret);
|
|
return;
|
|
}
|
|
|
|
acb->qiov_offset += acb->cur_qiov.size;
|
|
acb->cur_pos += acb->cur_qiov.size;
|
|
qemu_iovec_reset(&acb->cur_qiov);
|
|
|
|
/* Complete request */
|
|
if (acb->cur_pos >= acb->end_pos) {
|
|
qed_aio_complete(acb, 0);
|
|
return;
|
|
}
|
|
|
|
/* Find next cluster and start I/O */
|
|
qed_find_cluster(s, &acb->request,
|
|
acb->cur_pos, acb->end_pos - acb->cur_pos,
|
|
io_fn, acb);
|
|
}
|
|
|
|
static BlockDriverAIOCB *qed_aio_setup(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb,
|
|
void *opaque, bool is_write)
|
|
{
|
|
QEDAIOCB *acb = qemu_aio_get(&qed_aio_pool, bs, cb, opaque);
|
|
|
|
trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors,
|
|
opaque, is_write);
|
|
|
|
acb->is_write = is_write;
|
|
acb->finished = NULL;
|
|
acb->qiov = qiov;
|
|
acb->qiov_offset = 0;
|
|
acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE;
|
|
acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE;
|
|
acb->request.l2_table = NULL;
|
|
qemu_iovec_init(&acb->cur_qiov, qiov->niov);
|
|
|
|
/* Start request */
|
|
qed_aio_next_io(acb, 0);
|
|
return &acb->common;
|
|
}
|
|
|
|
static BlockDriverAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb,
|
|
void *opaque)
|
|
{
|
|
return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, false);
|
|
}
|
|
|
|
static BlockDriverAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb,
|
|
void *opaque)
|
|
{
|
|
return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, true);
|
|
}
|
|
|
|
static BlockDriverAIOCB *bdrv_qed_aio_flush(BlockDriverState *bs,
|
|
BlockDriverCompletionFunc *cb,
|
|
void *opaque)
|
|
{
|
|
return bdrv_aio_flush(bs->file, cb, opaque);
|
|
}
|
|
|
|
static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset)
|
|
{
|
|
BDRVQEDState *s = bs->opaque;
|
|
uint64_t old_image_size;
|
|
int ret;
|
|
|
|
if (!qed_is_image_size_valid(offset, s->header.cluster_size,
|
|
s->header.table_size)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Shrinking is currently not supported */
|
|
if ((uint64_t)offset < s->header.image_size) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
old_image_size = s->header.image_size;
|
|
s->header.image_size = offset;
|
|
ret = qed_write_header_sync(s);
|
|
if (ret < 0) {
|
|
s->header.image_size = old_image_size;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int64_t bdrv_qed_getlength(BlockDriverState *bs)
|
|
{
|
|
BDRVQEDState *s = bs->opaque;
|
|
return s->header.image_size;
|
|
}
|
|
|
|
static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
BDRVQEDState *s = bs->opaque;
|
|
|
|
memset(bdi, 0, sizeof(*bdi));
|
|
bdi->cluster_size = s->header.cluster_size;
|
|
return 0;
|
|
}
|
|
|
|
static int bdrv_qed_change_backing_file(BlockDriverState *bs,
|
|
const char *backing_file,
|
|
const char *backing_fmt)
|
|
{
|
|
BDRVQEDState *s = bs->opaque;
|
|
QEDHeader new_header, le_header;
|
|
void *buffer;
|
|
size_t buffer_len, backing_file_len;
|
|
int ret;
|
|
|
|
/* Refuse to set backing filename if unknown compat feature bits are
|
|
* active. If the image uses an unknown compat feature then we may not
|
|
* know the layout of data following the header structure and cannot safely
|
|
* add a new string.
|
|
*/
|
|
if (backing_file && (s->header.compat_features &
|
|
~QED_COMPAT_FEATURE_MASK)) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
memcpy(&new_header, &s->header, sizeof(new_header));
|
|
|
|
new_header.features &= ~(QED_F_BACKING_FILE |
|
|
QED_F_BACKING_FORMAT_NO_PROBE);
|
|
|
|
/* Adjust feature flags */
|
|
if (backing_file) {
|
|
new_header.features |= QED_F_BACKING_FILE;
|
|
|
|
if (qed_fmt_is_raw(backing_fmt)) {
|
|
new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
|
|
}
|
|
}
|
|
|
|
/* Calculate new header size */
|
|
backing_file_len = 0;
|
|
|
|
if (backing_file) {
|
|
backing_file_len = strlen(backing_file);
|
|
}
|
|
|
|
buffer_len = sizeof(new_header);
|
|
new_header.backing_filename_offset = buffer_len;
|
|
new_header.backing_filename_size = backing_file_len;
|
|
buffer_len += backing_file_len;
|
|
|
|
/* Make sure we can rewrite header without failing */
|
|
if (buffer_len > new_header.header_size * new_header.cluster_size) {
|
|
return -ENOSPC;
|
|
}
|
|
|
|
/* Prepare new header */
|
|
buffer = qemu_malloc(buffer_len);
|
|
|
|
qed_header_cpu_to_le(&new_header, &le_header);
|
|
memcpy(buffer, &le_header, sizeof(le_header));
|
|
buffer_len = sizeof(le_header);
|
|
|
|
memcpy(buffer + buffer_len, backing_file, backing_file_len);
|
|
buffer_len += backing_file_len;
|
|
|
|
/* Write new header */
|
|
ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len);
|
|
qemu_free(buffer);
|
|
if (ret == 0) {
|
|
memcpy(&s->header, &new_header, sizeof(new_header));
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result)
|
|
{
|
|
BDRVQEDState *s = bs->opaque;
|
|
|
|
return qed_check(s, result, false);
|
|
}
|
|
|
|
static QEMUOptionParameter qed_create_options[] = {
|
|
{
|
|
.name = BLOCK_OPT_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "Virtual disk size (in bytes)"
|
|
}, {
|
|
.name = BLOCK_OPT_BACKING_FILE,
|
|
.type = OPT_STRING,
|
|
.help = "File name of a base image"
|
|
}, {
|
|
.name = BLOCK_OPT_BACKING_FMT,
|
|
.type = OPT_STRING,
|
|
.help = "Image format of the base image"
|
|
}, {
|
|
.name = BLOCK_OPT_CLUSTER_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "Cluster size (in bytes)",
|
|
.value = { .n = QED_DEFAULT_CLUSTER_SIZE },
|
|
}, {
|
|
.name = BLOCK_OPT_TABLE_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "L1/L2 table size (in clusters)"
|
|
},
|
|
{ /* end of list */ }
|
|
};
|
|
|
|
static BlockDriver bdrv_qed = {
|
|
.format_name = "qed",
|
|
.instance_size = sizeof(BDRVQEDState),
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.create_options = qed_create_options,
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|
|
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.bdrv_probe = bdrv_qed_probe,
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|
.bdrv_open = bdrv_qed_open,
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|
.bdrv_close = bdrv_qed_close,
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|
.bdrv_create = bdrv_qed_create,
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|
.bdrv_flush = bdrv_qed_flush,
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|
.bdrv_is_allocated = bdrv_qed_is_allocated,
|
|
.bdrv_make_empty = bdrv_qed_make_empty,
|
|
.bdrv_aio_readv = bdrv_qed_aio_readv,
|
|
.bdrv_aio_writev = bdrv_qed_aio_writev,
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|
.bdrv_aio_flush = bdrv_qed_aio_flush,
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|
.bdrv_truncate = bdrv_qed_truncate,
|
|
.bdrv_getlength = bdrv_qed_getlength,
|
|
.bdrv_get_info = bdrv_qed_get_info,
|
|
.bdrv_change_backing_file = bdrv_qed_change_backing_file,
|
|
.bdrv_check = bdrv_qed_check,
|
|
};
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|
|
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static void bdrv_qed_init(void)
|
|
{
|
|
bdrv_register(&bdrv_qed);
|
|
}
|
|
|
|
block_init(bdrv_qed_init);
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