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| 1 |
/*
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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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* 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 "qed.h" |
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|
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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; |
| 22 |
|
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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(); |
| 27 |
} |
| 28 |
} |
| 29 |
|
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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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|
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static int bdrv_qed_probe(const uint8_t *buf, int buf_size, |
| 36 |
const char *filename) |
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{
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const QEDHeader *header = (const QEDHeader *)buf; |
| 39 |
|
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if (buf_size < sizeof(*header)) { |
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return 0; |
| 42 |
} |
| 43 |
if (le32_to_cpu(header->magic) != QED_MAGIC) {
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return 0; |
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} |
| 46 |
return 100; |
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} |
| 48 |
|
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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) |
| 55 |
{
|
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return fmt && strcmp(fmt, "raw") == 0; |
| 57 |
} |
| 58 |
|
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static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) |
| 60 |
{
|
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cpu->magic = le32_to_cpu(le->magic); |
| 62 |
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); |
| 72 |
} |
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|
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static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) |
| 75 |
{
|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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/**
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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, |
| 148 |
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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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return l2_size * table_entries;
|
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} |
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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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|
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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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|
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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 */ |
| 217 |
} |
| 218 |
if (image_size > qed_max_image_size(cluster_size, table_size)) {
|
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return false; /* image is too large */ |
| 220 |
} |
| 221 |
return true; |
| 222 |
} |
| 223 |
|
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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)
|
| 238 |
{
|
| 239 |
int ret;
|
| 240 |
if (n >= buflen) {
|
| 241 |
return -EINVAL;
|
| 242 |
} |
| 243 |
ret = bdrv_pread(file, offset, buf, n); |
| 244 |
if (ret < 0) { |
| 245 |
return ret;
|
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} |
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buf[n] = '\0';
|
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return 0; |
| 249 |
} |
| 250 |
|
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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) |
| 263 |
{
|
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uint64_t offset = s->file_size; |
| 265 |
s->file_size += n * s->header.cluster_size; |
| 266 |
return offset;
|
| 267 |
} |
| 268 |
|
| 269 |
QEDTable *qed_alloc_table(BDRVQEDState *s) |
| 270 |
{
|
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/* Honor O_DIRECT memory alignment requirements */
|
| 272 |
return qemu_blockalign(s->bs,
|
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s->header.cluster_size * s->header.table_size); |
| 274 |
} |
| 275 |
|
| 276 |
/**
|
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* Allocate a new zeroed L2 table
|
| 278 |
*/
|
| 279 |
static CachedL2Table *qed_new_l2_table(BDRVQEDState *s)
|
| 280 |
{
|
| 281 |
CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); |
| 282 |
|
| 283 |
l2_table->table = qed_alloc_table(s); |
| 284 |
l2_table->offset = qed_alloc_clusters(s, s->header.table_size); |
| 285 |
|
| 286 |
memset(l2_table->table->offsets, 0,
|
| 287 |
s->header.cluster_size * s->header.table_size); |
| 288 |
return l2_table;
|
| 289 |
} |
| 290 |
|
| 291 |
static void qed_aio_next_io(void *opaque, int ret); |
| 292 |
|
| 293 |
static int bdrv_qed_open(BlockDriverState *bs, int flags) |
| 294 |
{
|
| 295 |
BDRVQEDState *s = bs->opaque; |
| 296 |
QEDHeader le_header; |
| 297 |
int64_t file_size; |
| 298 |
int ret;
|
| 299 |
|
| 300 |
s->bs = bs; |
| 301 |
QSIMPLEQ_INIT(&s->allocating_write_reqs); |
| 302 |
|
| 303 |
ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header)); |
| 304 |
if (ret < 0) { |
| 305 |
return ret;
|
| 306 |
} |
| 307 |
ret = 0; /* ret should always be 0 or -errno */ |
| 308 |
qed_header_le_to_cpu(&le_header, &s->header); |
| 309 |
|
| 310 |
if (s->header.magic != QED_MAGIC) {
|
| 311 |
return -EINVAL;
|
| 312 |
} |
| 313 |
if (s->header.features & ~QED_FEATURE_MASK) {
|
| 314 |
return -ENOTSUP; /* image uses unsupported feature bits */ |
| 315 |
} |
| 316 |
if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
|
| 317 |
return -EINVAL;
|
| 318 |
} |
| 319 |
|
| 320 |
/* Round down file size to the last cluster */
|
| 321 |
file_size = bdrv_getlength(bs->file); |
| 322 |
if (file_size < 0) { |
| 323 |
return file_size;
|
| 324 |
} |
| 325 |
s->file_size = qed_start_of_cluster(s, file_size); |
| 326 |
|
| 327 |
if (!qed_is_table_size_valid(s->header.table_size)) {
|
| 328 |
return -EINVAL;
|
| 329 |
} |
| 330 |
if (!qed_is_image_size_valid(s->header.image_size,
|
| 331 |
s->header.cluster_size, |
| 332 |
s->header.table_size)) {
|
| 333 |
return -EINVAL;
|
| 334 |
} |
| 335 |
if (!qed_check_table_offset(s, s->header.l1_table_offset)) {
|
| 336 |
return -EINVAL;
|
| 337 |
} |
| 338 |
|
| 339 |
s->table_nelems = (s->header.cluster_size * s->header.table_size) / |
| 340 |
sizeof(uint64_t);
|
| 341 |
s->l2_shift = ffs(s->header.cluster_size) - 1;
|
| 342 |
s->l2_mask = s->table_nelems - 1;
|
| 343 |
s->l1_shift = s->l2_shift + ffs(s->table_nelems) - 1;
|
| 344 |
|
| 345 |
if ((s->header.features & QED_F_BACKING_FILE)) {
|
| 346 |
if ((uint64_t)s->header.backing_filename_offset +
|
| 347 |
s->header.backing_filename_size > |
| 348 |
s->header.cluster_size * s->header.header_size) {
|
| 349 |
return -EINVAL;
|
| 350 |
} |
| 351 |
|
| 352 |
ret = qed_read_string(bs->file, s->header.backing_filename_offset, |
| 353 |
s->header.backing_filename_size, bs->backing_file, |
| 354 |
sizeof(bs->backing_file));
|
| 355 |
if (ret < 0) { |
| 356 |
return ret;
|
| 357 |
} |
| 358 |
|
| 359 |
if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) {
|
| 360 |
pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); |
| 361 |
} |
| 362 |
} |
| 363 |
|
| 364 |
/* Reset unknown autoclear feature bits. This is a backwards
|
| 365 |
* compatibility mechanism that allows images to be opened by older
|
| 366 |
* programs, which "knock out" unknown feature bits. When an image is
|
| 367 |
* opened by a newer program again it can detect that the autoclear
|
| 368 |
* feature is no longer valid.
|
| 369 |
*/
|
| 370 |
if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 && |
| 371 |
!bdrv_is_read_only(bs->file)) {
|
| 372 |
s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK; |
| 373 |
|
| 374 |
ret = qed_write_header_sync(s); |
| 375 |
if (ret) {
|
| 376 |
return ret;
|
| 377 |
} |
| 378 |
|
| 379 |
/* From here on only known autoclear feature bits are valid */
|
| 380 |
bdrv_flush(bs->file); |
| 381 |
} |
| 382 |
|
| 383 |
s->l1_table = qed_alloc_table(s); |
| 384 |
qed_init_l2_cache(&s->l2_cache); |
| 385 |
|
| 386 |
ret = qed_read_l1_table_sync(s); |
| 387 |
if (ret) {
|
| 388 |
goto out;
|
| 389 |
} |
| 390 |
|
| 391 |
/* If image was not closed cleanly, check consistency */
|
| 392 |
if (s->header.features & QED_F_NEED_CHECK) {
|
| 393 |
/* Read-only images cannot be fixed. There is no risk of corruption
|
| 394 |
* since write operations are not possible. Therefore, allow
|
| 395 |
* potentially inconsistent images to be opened read-only. This can
|
| 396 |
* aid data recovery from an otherwise inconsistent image.
|
| 397 |
*/
|
| 398 |
if (!bdrv_is_read_only(bs->file)) {
|
| 399 |
BdrvCheckResult result = {0};
|
| 400 |
|
| 401 |
ret = qed_check(s, &result, true);
|
| 402 |
if (!ret && !result.corruptions && !result.check_errors) {
|
| 403 |
/* Ensure fixes reach storage before clearing check bit */
|
| 404 |
bdrv_flush(s->bs); |
| 405 |
|
| 406 |
s->header.features &= ~QED_F_NEED_CHECK; |
| 407 |
qed_write_header_sync(s); |
| 408 |
} |
| 409 |
} |
| 410 |
} |
| 411 |
|
| 412 |
out:
|
| 413 |
if (ret) {
|
| 414 |
qed_free_l2_cache(&s->l2_cache); |
| 415 |
qemu_vfree(s->l1_table); |
| 416 |
} |
| 417 |
return ret;
|
| 418 |
} |
| 419 |
|
| 420 |
static void bdrv_qed_close(BlockDriverState *bs) |
| 421 |
{
|
| 422 |
BDRVQEDState *s = bs->opaque; |
| 423 |
|
| 424 |
/* Ensure writes reach stable storage */
|
| 425 |
bdrv_flush(bs->file); |
| 426 |
|
| 427 |
/* Clean shutdown, no check required on next open */
|
| 428 |
if (s->header.features & QED_F_NEED_CHECK) {
|
| 429 |
s->header.features &= ~QED_F_NEED_CHECK; |
| 430 |
qed_write_header_sync(s); |
| 431 |
} |
| 432 |
|
| 433 |
qed_free_l2_cache(&s->l2_cache); |
| 434 |
qemu_vfree(s->l1_table); |
| 435 |
} |
| 436 |
|
| 437 |
static int bdrv_qed_flush(BlockDriverState *bs) |
| 438 |
{
|
| 439 |
return bdrv_flush(bs->file);
|
| 440 |
} |
| 441 |
|
| 442 |
static int qed_create(const char *filename, uint32_t cluster_size, |
| 443 |
uint64_t image_size, uint32_t table_size, |
| 444 |
const char *backing_file, const char *backing_fmt) |
| 445 |
{
|
| 446 |
QEDHeader header = {
|
| 447 |
.magic = QED_MAGIC, |
| 448 |
.cluster_size = cluster_size, |
| 449 |
.table_size = table_size, |
| 450 |
.header_size = 1,
|
| 451 |
.features = 0,
|
| 452 |
.compat_features = 0,
|
| 453 |
.l1_table_offset = cluster_size, |
| 454 |
.image_size = image_size, |
| 455 |
}; |
| 456 |
QEDHeader le_header; |
| 457 |
uint8_t *l1_table = NULL;
|
| 458 |
size_t l1_size = header.cluster_size * header.table_size; |
| 459 |
int ret = 0; |
| 460 |
BlockDriverState *bs = NULL;
|
| 461 |
|
| 462 |
ret = bdrv_create_file(filename, NULL);
|
| 463 |
if (ret < 0) { |
| 464 |
return ret;
|
| 465 |
} |
| 466 |
|
| 467 |
ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR | BDRV_O_CACHE_WB); |
| 468 |
if (ret < 0) { |
| 469 |
return ret;
|
| 470 |
} |
| 471 |
|
| 472 |
/* File must start empty and grow, check truncate is supported */
|
| 473 |
ret = bdrv_truncate(bs, 0);
|
| 474 |
if (ret < 0) { |
| 475 |
goto out;
|
| 476 |
} |
| 477 |
|
| 478 |
if (backing_file) {
|
| 479 |
header.features |= QED_F_BACKING_FILE; |
| 480 |
header.backing_filename_offset = sizeof(le_header);
|
| 481 |
header.backing_filename_size = strlen(backing_file); |
| 482 |
|
| 483 |
if (qed_fmt_is_raw(backing_fmt)) {
|
| 484 |
header.features |= QED_F_BACKING_FORMAT_NO_PROBE; |
| 485 |
} |
| 486 |
} |
| 487 |
|
| 488 |
qed_header_cpu_to_le(&header, &le_header); |
| 489 |
ret = bdrv_pwrite(bs, 0, &le_header, sizeof(le_header)); |
| 490 |
if (ret < 0) { |
| 491 |
goto out;
|
| 492 |
} |
| 493 |
ret = bdrv_pwrite(bs, sizeof(le_header), backing_file,
|
| 494 |
header.backing_filename_size); |
| 495 |
if (ret < 0) { |
| 496 |
goto out;
|
| 497 |
} |
| 498 |
|
| 499 |
l1_table = qemu_mallocz(l1_size); |
| 500 |
ret = bdrv_pwrite(bs, header.l1_table_offset, l1_table, l1_size); |
| 501 |
if (ret < 0) { |
| 502 |
goto out;
|
| 503 |
} |
| 504 |
|
| 505 |
ret = 0; /* success */ |
| 506 |
out:
|
| 507 |
qemu_free(l1_table); |
| 508 |
bdrv_delete(bs); |
| 509 |
return ret;
|
| 510 |
} |
| 511 |
|
| 512 |
static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options) |
| 513 |
{
|
| 514 |
uint64_t image_size = 0;
|
| 515 |
uint32_t cluster_size = QED_DEFAULT_CLUSTER_SIZE; |
| 516 |
uint32_t table_size = QED_DEFAULT_TABLE_SIZE; |
| 517 |
const char *backing_file = NULL; |
| 518 |
const char *backing_fmt = NULL; |
| 519 |
|
| 520 |
while (options && options->name) {
|
| 521 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
| 522 |
image_size = options->value.n; |
| 523 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
| 524 |
backing_file = options->value.s; |
| 525 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { |
| 526 |
backing_fmt = options->value.s; |
| 527 |
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { |
| 528 |
if (options->value.n) {
|
| 529 |
cluster_size = options->value.n; |
| 530 |
} |
| 531 |
} else if (!strcmp(options->name, BLOCK_OPT_TABLE_SIZE)) { |
| 532 |
if (options->value.n) {
|
| 533 |
table_size = options->value.n; |
| 534 |
} |
| 535 |
} |
| 536 |
options++; |
| 537 |
} |
| 538 |
|
| 539 |
if (!qed_is_cluster_size_valid(cluster_size)) {
|
| 540 |
fprintf(stderr, "QED cluster size must be within range [%u, %u] and power of 2\n",
|
| 541 |
QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE); |
| 542 |
return -EINVAL;
|
| 543 |
} |
| 544 |
if (!qed_is_table_size_valid(table_size)) {
|
| 545 |
fprintf(stderr, "QED table size must be within range [%u, %u] and power of 2\n",
|
| 546 |
QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE); |
| 547 |
return -EINVAL;
|
| 548 |
} |
| 549 |
if (!qed_is_image_size_valid(image_size, cluster_size, table_size)) {
|
| 550 |
fprintf(stderr, "QED image size must be a non-zero multiple of "
|
| 551 |
"cluster size and less than %" PRIu64 " bytes\n", |
| 552 |
qed_max_image_size(cluster_size, table_size)); |
| 553 |
return -EINVAL;
|
| 554 |
} |
| 555 |
|
| 556 |
return qed_create(filename, cluster_size, image_size, table_size,
|
| 557 |
backing_file, backing_fmt); |
| 558 |
} |
| 559 |
|
| 560 |
typedef struct { |
| 561 |
int is_allocated;
|
| 562 |
int *pnum;
|
| 563 |
} QEDIsAllocatedCB; |
| 564 |
|
| 565 |
static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t len) |
| 566 |
{
|
| 567 |
QEDIsAllocatedCB *cb = opaque; |
| 568 |
*cb->pnum = len / BDRV_SECTOR_SIZE; |
| 569 |
cb->is_allocated = ret == QED_CLUSTER_FOUND; |
| 570 |
} |
| 571 |
|
| 572 |
static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num, |
| 573 |
int nb_sectors, int *pnum) |
| 574 |
{
|
| 575 |
BDRVQEDState *s = bs->opaque; |
| 576 |
uint64_t pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE; |
| 577 |
size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE; |
| 578 |
QEDIsAllocatedCB cb = {
|
| 579 |
.is_allocated = -1,
|
| 580 |
.pnum = pnum, |
| 581 |
}; |
| 582 |
QEDRequest request = { .l2_table = NULL };
|
| 583 |
|
| 584 |
async_context_push(); |
| 585 |
|
| 586 |
qed_find_cluster(s, &request, pos, len, qed_is_allocated_cb, &cb); |
| 587 |
|
| 588 |
while (cb.is_allocated == -1) { |
| 589 |
qemu_aio_wait(); |
| 590 |
} |
| 591 |
|
| 592 |
async_context_pop(); |
| 593 |
|
| 594 |
qed_unref_l2_cache_entry(request.l2_table); |
| 595 |
|
| 596 |
return cb.is_allocated;
|
| 597 |
} |
| 598 |
|
| 599 |
static int bdrv_qed_make_empty(BlockDriverState *bs) |
| 600 |
{
|
| 601 |
return -ENOTSUP;
|
| 602 |
} |
| 603 |
|
| 604 |
static BDRVQEDState *acb_to_s(QEDAIOCB *acb)
|
| 605 |
{
|
| 606 |
return acb->common.bs->opaque;
|
| 607 |
} |
| 608 |
|
| 609 |
/**
|
| 610 |
* Read from the backing file or zero-fill if no backing file
|
| 611 |
*
|
| 612 |
* @s: QED state
|
| 613 |
* @pos: Byte position in device
|
| 614 |
* @qiov: Destination I/O vector
|
| 615 |
* @cb: Completion function
|
| 616 |
* @opaque: User data for completion function
|
| 617 |
*
|
| 618 |
* This function reads qiov->size bytes starting at pos from the backing file.
|
| 619 |
* If there is no backing file then zeroes are read.
|
| 620 |
*/
|
| 621 |
static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos, |
| 622 |
QEMUIOVector *qiov, |
| 623 |
BlockDriverCompletionFunc *cb, void *opaque)
|
| 624 |
{
|
| 625 |
BlockDriverAIOCB *aiocb; |
| 626 |
uint64_t backing_length = 0;
|
| 627 |
size_t size; |
| 628 |
|
| 629 |
/* If there is a backing file, get its length. Treat the absence of a
|
| 630 |
* backing file like a zero length backing file.
|
| 631 |
*/
|
| 632 |
if (s->bs->backing_hd) {
|
| 633 |
int64_t l = bdrv_getlength(s->bs->backing_hd); |
| 634 |
if (l < 0) { |
| 635 |
cb(opaque, l); |
| 636 |
return;
|
| 637 |
} |
| 638 |
backing_length = l; |
| 639 |
} |
| 640 |
|
| 641 |
/* Zero all sectors if reading beyond the end of the backing file */
|
| 642 |
if (pos >= backing_length ||
|
| 643 |
pos + qiov->size > backing_length) {
|
| 644 |
qemu_iovec_memset(qiov, 0, qiov->size);
|
| 645 |
} |
| 646 |
|
| 647 |
/* Complete now if there are no backing file sectors to read */
|
| 648 |
if (pos >= backing_length) {
|
| 649 |
cb(opaque, 0);
|
| 650 |
return;
|
| 651 |
} |
| 652 |
|
| 653 |
/* If the read straddles the end of the backing file, shorten it */
|
| 654 |
size = MIN((uint64_t)backing_length - pos, qiov->size); |
| 655 |
|
| 656 |
BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING); |
| 657 |
aiocb = bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE, |
| 658 |
qiov, size / BDRV_SECTOR_SIZE, cb, opaque); |
| 659 |
if (!aiocb) {
|
| 660 |
cb(opaque, -EIO); |
| 661 |
} |
| 662 |
} |
| 663 |
|
| 664 |
typedef struct { |
| 665 |
GenericCB gencb; |
| 666 |
BDRVQEDState *s; |
| 667 |
QEMUIOVector qiov; |
| 668 |
struct iovec iov;
|
| 669 |
uint64_t offset; |
| 670 |
} CopyFromBackingFileCB; |
| 671 |
|
| 672 |
static void qed_copy_from_backing_file_cb(void *opaque, int ret) |
| 673 |
{
|
| 674 |
CopyFromBackingFileCB *copy_cb = opaque; |
| 675 |
qemu_vfree(copy_cb->iov.iov_base); |
| 676 |
gencb_complete(©_cb->gencb, ret); |
| 677 |
} |
| 678 |
|
| 679 |
static void qed_copy_from_backing_file_write(void *opaque, int ret) |
| 680 |
{
|
| 681 |
CopyFromBackingFileCB *copy_cb = opaque; |
| 682 |
BDRVQEDState *s = copy_cb->s; |
| 683 |
BlockDriverAIOCB *aiocb; |
| 684 |
|
| 685 |
if (ret) {
|
| 686 |
qed_copy_from_backing_file_cb(copy_cb, ret); |
| 687 |
return;
|
| 688 |
} |
| 689 |
|
| 690 |
BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); |
| 691 |
aiocb = bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE, |
| 692 |
©_cb->qiov, |
| 693 |
copy_cb->qiov.size / BDRV_SECTOR_SIZE, |
| 694 |
qed_copy_from_backing_file_cb, copy_cb); |
| 695 |
if (!aiocb) {
|
| 696 |
qed_copy_from_backing_file_cb(copy_cb, -EIO); |
| 697 |
} |
| 698 |
} |
| 699 |
|
| 700 |
/**
|
| 701 |
* Copy data from backing file into the image
|
| 702 |
*
|
| 703 |
* @s: QED state
|
| 704 |
* @pos: Byte position in device
|
| 705 |
* @len: Number of bytes
|
| 706 |
* @offset: Byte offset in image file
|
| 707 |
* @cb: Completion function
|
| 708 |
* @opaque: User data for completion function
|
| 709 |
*/
|
| 710 |
static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos, |
| 711 |
uint64_t len, uint64_t offset, |
| 712 |
BlockDriverCompletionFunc *cb, |
| 713 |
void *opaque)
|
| 714 |
{
|
| 715 |
CopyFromBackingFileCB *copy_cb; |
| 716 |
|
| 717 |
/* Skip copy entirely if there is no work to do */
|
| 718 |
if (len == 0) { |
| 719 |
cb(opaque, 0);
|
| 720 |
return;
|
| 721 |
} |
| 722 |
|
| 723 |
copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque);
|
| 724 |
copy_cb->s = s; |
| 725 |
copy_cb->offset = offset; |
| 726 |
copy_cb->iov.iov_base = qemu_blockalign(s->bs, len); |
| 727 |
copy_cb->iov.iov_len = len; |
| 728 |
qemu_iovec_init_external(©_cb->qiov, ©_cb->iov, 1);
|
| 729 |
|
| 730 |
qed_read_backing_file(s, pos, ©_cb->qiov, |
| 731 |
qed_copy_from_backing_file_write, copy_cb); |
| 732 |
} |
| 733 |
|
| 734 |
/**
|
| 735 |
* Link one or more contiguous clusters into a table
|
| 736 |
*
|
| 737 |
* @s: QED state
|
| 738 |
* @table: L2 table
|
| 739 |
* @index: First cluster index
|
| 740 |
* @n: Number of contiguous clusters
|
| 741 |
* @cluster: First cluster byte offset in image file
|
| 742 |
*/
|
| 743 |
static void qed_update_l2_table(BDRVQEDState *s, QEDTable *table, int index, |
| 744 |
unsigned int n, uint64_t cluster) |
| 745 |
{
|
| 746 |
int i;
|
| 747 |
for (i = index; i < index + n; i++) {
|
| 748 |
table->offsets[i] = cluster; |
| 749 |
cluster += s->header.cluster_size; |
| 750 |
} |
| 751 |
} |
| 752 |
|
| 753 |
static void qed_aio_complete_bh(void *opaque) |
| 754 |
{
|
| 755 |
QEDAIOCB *acb = opaque; |
| 756 |
BlockDriverCompletionFunc *cb = acb->common.cb; |
| 757 |
void *user_opaque = acb->common.opaque;
|
| 758 |
int ret = acb->bh_ret;
|
| 759 |
bool *finished = acb->finished;
|
| 760 |
|
| 761 |
qemu_bh_delete(acb->bh); |
| 762 |
qemu_aio_release(acb); |
| 763 |
|
| 764 |
/* Invoke callback */
|
| 765 |
cb(user_opaque, ret); |
| 766 |
|
| 767 |
/* Signal cancel completion */
|
| 768 |
if (finished) {
|
| 769 |
*finished = true;
|
| 770 |
} |
| 771 |
} |
| 772 |
|
| 773 |
static void qed_aio_complete(QEDAIOCB *acb, int ret) |
| 774 |
{
|
| 775 |
BDRVQEDState *s = acb_to_s(acb); |
| 776 |
|
| 777 |
trace_qed_aio_complete(s, acb, ret); |
| 778 |
|
| 779 |
/* Free resources */
|
| 780 |
qemu_iovec_destroy(&acb->cur_qiov); |
| 781 |
qed_unref_l2_cache_entry(acb->request.l2_table); |
| 782 |
|
| 783 |
/* Arrange for a bh to invoke the completion function */
|
| 784 |
acb->bh_ret = ret; |
| 785 |
acb->bh = qemu_bh_new(qed_aio_complete_bh, acb); |
| 786 |
qemu_bh_schedule(acb->bh); |
| 787 |
|
| 788 |
/* Start next allocating write request waiting behind this one. Note that
|
| 789 |
* requests enqueue themselves when they first hit an unallocated cluster
|
| 790 |
* but they wait until the entire request is finished before waking up the
|
| 791 |
* next request in the queue. This ensures that we don't cycle through
|
| 792 |
* requests multiple times but rather finish one at a time completely.
|
| 793 |
*/
|
| 794 |
if (acb == QSIMPLEQ_FIRST(&s->allocating_write_reqs)) {
|
| 795 |
QSIMPLEQ_REMOVE_HEAD(&s->allocating_write_reqs, next); |
| 796 |
acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs); |
| 797 |
if (acb) {
|
| 798 |
qed_aio_next_io(acb, 0);
|
| 799 |
} |
| 800 |
} |
| 801 |
} |
| 802 |
|
| 803 |
/**
|
| 804 |
* Commit the current L2 table to the cache
|
| 805 |
*/
|
| 806 |
static void qed_commit_l2_update(void *opaque, int ret) |
| 807 |
{
|
| 808 |
QEDAIOCB *acb = opaque; |
| 809 |
BDRVQEDState *s = acb_to_s(acb); |
| 810 |
CachedL2Table *l2_table = acb->request.l2_table; |
| 811 |
|
| 812 |
qed_commit_l2_cache_entry(&s->l2_cache, l2_table); |
| 813 |
|
| 814 |
/* This is guaranteed to succeed because we just committed the entry to the
|
| 815 |
* cache.
|
| 816 |
*/
|
| 817 |
acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, |
| 818 |
l2_table->offset); |
| 819 |
assert(acb->request.l2_table != NULL);
|
| 820 |
|
| 821 |
qed_aio_next_io(opaque, ret); |
| 822 |
} |
| 823 |
|
| 824 |
/**
|
| 825 |
* Update L1 table with new L2 table offset and write it out
|
| 826 |
*/
|
| 827 |
static void qed_aio_write_l1_update(void *opaque, int ret) |
| 828 |
{
|
| 829 |
QEDAIOCB *acb = opaque; |
| 830 |
BDRVQEDState *s = acb_to_s(acb); |
| 831 |
int index;
|
| 832 |
|
| 833 |
if (ret) {
|
| 834 |
qed_aio_complete(acb, ret); |
| 835 |
return;
|
| 836 |
} |
| 837 |
|
| 838 |
index = qed_l1_index(s, acb->cur_pos); |
| 839 |
s->l1_table->offsets[index] = acb->request.l2_table->offset; |
| 840 |
|
| 841 |
qed_write_l1_table(s, index, 1, qed_commit_l2_update, acb);
|
| 842 |
} |
| 843 |
|
| 844 |
/**
|
| 845 |
* Update L2 table with new cluster offsets and write them out
|
| 846 |
*/
|
| 847 |
static void qed_aio_write_l2_update(void *opaque, int ret) |
| 848 |
{
|
| 849 |
QEDAIOCB *acb = opaque; |
| 850 |
BDRVQEDState *s = acb_to_s(acb); |
| 851 |
bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1;
|
| 852 |
int index;
|
| 853 |
|
| 854 |
if (ret) {
|
| 855 |
goto err;
|
| 856 |
} |
| 857 |
|
| 858 |
if (need_alloc) {
|
| 859 |
qed_unref_l2_cache_entry(acb->request.l2_table); |
| 860 |
acb->request.l2_table = qed_new_l2_table(s); |
| 861 |
} |
| 862 |
|
| 863 |
index = qed_l2_index(s, acb->cur_pos); |
| 864 |
qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, |
| 865 |
acb->cur_cluster); |
| 866 |
|
| 867 |
if (need_alloc) {
|
| 868 |
/* Write out the whole new L2 table */
|
| 869 |
qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true, |
| 870 |
qed_aio_write_l1_update, acb); |
| 871 |
} else {
|
| 872 |
/* Write out only the updated part of the L2 table */
|
| 873 |
qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, false,
|
| 874 |
qed_aio_next_io, acb); |
| 875 |
} |
| 876 |
return;
|
| 877 |
|
| 878 |
err:
|
| 879 |
qed_aio_complete(acb, ret); |
| 880 |
} |
| 881 |
|
| 882 |
/**
|
| 883 |
* Flush new data clusters before updating the L2 table
|
| 884 |
*
|
| 885 |
* This flush is necessary when a backing file is in use. A crash during an
|
| 886 |
* allocating write could result in empty clusters in the image. If the write
|
| 887 |
* only touched a subregion of the cluster, then backing image sectors have
|
| 888 |
* been lost in the untouched region. The solution is to flush after writing a
|
| 889 |
* new data cluster and before updating the L2 table.
|
| 890 |
*/
|
| 891 |
static void qed_aio_write_flush_before_l2_update(void *opaque, int ret) |
| 892 |
{
|
| 893 |
QEDAIOCB *acb = opaque; |
| 894 |
BDRVQEDState *s = acb_to_s(acb); |
| 895 |
|
| 896 |
if (!bdrv_aio_flush(s->bs->file, qed_aio_write_l2_update, opaque)) {
|
| 897 |
qed_aio_complete(acb, -EIO); |
| 898 |
} |
| 899 |
} |
| 900 |
|
| 901 |
/**
|
| 902 |
* Write data to the image file
|
| 903 |
*/
|
| 904 |
static void qed_aio_write_main(void *opaque, int ret) |
| 905 |
{
|
| 906 |
QEDAIOCB *acb = opaque; |
| 907 |
BDRVQEDState *s = acb_to_s(acb); |
| 908 |
uint64_t offset = acb->cur_cluster + |
| 909 |
qed_offset_into_cluster(s, acb->cur_pos); |
| 910 |
BlockDriverCompletionFunc *next_fn; |
| 911 |
BlockDriverAIOCB *file_acb; |
| 912 |
|
| 913 |
trace_qed_aio_write_main(s, acb, ret, offset, acb->cur_qiov.size); |
| 914 |
|
| 915 |
if (ret) {
|
| 916 |
qed_aio_complete(acb, ret); |
| 917 |
return;
|
| 918 |
} |
| 919 |
|
| 920 |
if (acb->find_cluster_ret == QED_CLUSTER_FOUND) {
|
| 921 |
next_fn = qed_aio_next_io; |
| 922 |
} else {
|
| 923 |
if (s->bs->backing_hd) {
|
| 924 |
next_fn = qed_aio_write_flush_before_l2_update; |
| 925 |
} else {
|
| 926 |
next_fn = qed_aio_write_l2_update; |
| 927 |
} |
| 928 |
} |
| 929 |
|
| 930 |
BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); |
| 931 |
file_acb = bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE, |
| 932 |
&acb->cur_qiov, |
| 933 |
acb->cur_qiov.size / BDRV_SECTOR_SIZE, |
| 934 |
next_fn, acb); |
| 935 |
if (!file_acb) {
|
| 936 |
qed_aio_complete(acb, -EIO); |
| 937 |
} |
| 938 |
} |
| 939 |
|
| 940 |
/**
|
| 941 |
* Populate back untouched region of new data cluster
|
| 942 |
*/
|
| 943 |
static void qed_aio_write_postfill(void *opaque, int ret) |
| 944 |
{
|
| 945 |
QEDAIOCB *acb = opaque; |
| 946 |
BDRVQEDState *s = acb_to_s(acb); |
| 947 |
uint64_t start = acb->cur_pos + acb->cur_qiov.size; |
| 948 |
uint64_t len = |
| 949 |
qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start;
|
| 950 |
uint64_t offset = acb->cur_cluster + |
| 951 |
qed_offset_into_cluster(s, acb->cur_pos) + |
| 952 |
acb->cur_qiov.size; |
| 953 |
|
| 954 |
if (ret) {
|
| 955 |
qed_aio_complete(acb, ret); |
| 956 |
return;
|
| 957 |
} |
| 958 |
|
| 959 |
trace_qed_aio_write_postfill(s, acb, start, len, offset); |
| 960 |
qed_copy_from_backing_file(s, start, len, offset, |
| 961 |
qed_aio_write_main, acb); |
| 962 |
} |
| 963 |
|
| 964 |
/**
|
| 965 |
* Populate front untouched region of new data cluster
|
| 966 |
*/
|
| 967 |
static void qed_aio_write_prefill(void *opaque, int ret) |
| 968 |
{
|
| 969 |
QEDAIOCB *acb = opaque; |
| 970 |
BDRVQEDState *s = acb_to_s(acb); |
| 971 |
uint64_t start = qed_start_of_cluster(s, acb->cur_pos); |
| 972 |
uint64_t len = qed_offset_into_cluster(s, acb->cur_pos); |
| 973 |
|
| 974 |
trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); |
| 975 |
qed_copy_from_backing_file(s, start, len, acb->cur_cluster, |
| 976 |
qed_aio_write_postfill, acb); |
| 977 |
} |
| 978 |
|
| 979 |
/**
|
| 980 |
* Write new data cluster
|
| 981 |
*
|
| 982 |
* @acb: Write request
|
| 983 |
* @len: Length in bytes
|
| 984 |
*
|
| 985 |
* This path is taken when writing to previously unallocated clusters.
|
| 986 |
*/
|
| 987 |
static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) |
| 988 |
{
|
| 989 |
BDRVQEDState *s = acb_to_s(acb); |
| 990 |
|
| 991 |
/* Freeze this request if another allocating write is in progress */
|
| 992 |
if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs)) {
|
| 993 |
QSIMPLEQ_INSERT_TAIL(&s->allocating_write_reqs, acb, next); |
| 994 |
} |
| 995 |
if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs)) {
|
| 996 |
return; /* wait for existing request to finish */ |
| 997 |
} |
| 998 |
|
| 999 |
acb->cur_nclusters = qed_bytes_to_clusters(s, |
| 1000 |
qed_offset_into_cluster(s, acb->cur_pos) + len); |
| 1001 |
acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); |
| 1002 |
qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); |
| 1003 |
|
| 1004 |
/* Write new cluster if the image is already marked dirty */
|
| 1005 |
if (s->header.features & QED_F_NEED_CHECK) {
|
| 1006 |
qed_aio_write_prefill(acb, 0);
|
| 1007 |
return;
|
| 1008 |
} |
| 1009 |
|
| 1010 |
/* Mark the image dirty before writing the new cluster */
|
| 1011 |
s->header.features |= QED_F_NEED_CHECK; |
| 1012 |
qed_write_header(s, qed_aio_write_prefill, acb); |
| 1013 |
} |
| 1014 |
|
| 1015 |
/**
|
| 1016 |
* Write data cluster in place
|
| 1017 |
*
|
| 1018 |
* @acb: Write request
|
| 1019 |
* @offset: Cluster offset in bytes
|
| 1020 |
* @len: Length in bytes
|
| 1021 |
*
|
| 1022 |
* This path is taken when writing to already allocated clusters.
|
| 1023 |
*/
|
| 1024 |
static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, size_t len) |
| 1025 |
{
|
| 1026 |
/* Calculate the I/O vector */
|
| 1027 |
acb->cur_cluster = offset; |
| 1028 |
qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); |
| 1029 |
|
| 1030 |
/* Do the actual write */
|
| 1031 |
qed_aio_write_main(acb, 0);
|
| 1032 |
} |
| 1033 |
|
| 1034 |
/**
|
| 1035 |
* Write data cluster
|
| 1036 |
*
|
| 1037 |
* @opaque: Write request
|
| 1038 |
* @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
|
| 1039 |
* or -errno
|
| 1040 |
* @offset: Cluster offset in bytes
|
| 1041 |
* @len: Length in bytes
|
| 1042 |
*
|
| 1043 |
* Callback from qed_find_cluster().
|
| 1044 |
*/
|
| 1045 |
static void qed_aio_write_data(void *opaque, int ret, |
| 1046 |
uint64_t offset, size_t len) |
| 1047 |
{
|
| 1048 |
QEDAIOCB *acb = opaque; |
| 1049 |
|
| 1050 |
trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); |
| 1051 |
|
| 1052 |
acb->find_cluster_ret = ret; |
| 1053 |
|
| 1054 |
switch (ret) {
|
| 1055 |
case QED_CLUSTER_FOUND:
|
| 1056 |
qed_aio_write_inplace(acb, offset, len); |
| 1057 |
break;
|
| 1058 |
|
| 1059 |
case QED_CLUSTER_L2:
|
| 1060 |
case QED_CLUSTER_L1:
|
| 1061 |
qed_aio_write_alloc(acb, len); |
| 1062 |
break;
|
| 1063 |
|
| 1064 |
default:
|
| 1065 |
qed_aio_complete(acb, ret); |
| 1066 |
break;
|
| 1067 |
} |
| 1068 |
} |
| 1069 |
|
| 1070 |
/**
|
| 1071 |
* Read data cluster
|
| 1072 |
*
|
| 1073 |
* @opaque: Read request
|
| 1074 |
* @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
|
| 1075 |
* or -errno
|
| 1076 |
* @offset: Cluster offset in bytes
|
| 1077 |
* @len: Length in bytes
|
| 1078 |
*
|
| 1079 |
* Callback from qed_find_cluster().
|
| 1080 |
*/
|
| 1081 |
static void qed_aio_read_data(void *opaque, int ret, |
| 1082 |
uint64_t offset, size_t len) |
| 1083 |
{
|
| 1084 |
QEDAIOCB *acb = opaque; |
| 1085 |
BDRVQEDState *s = acb_to_s(acb); |
| 1086 |
BlockDriverState *bs = acb->common.bs; |
| 1087 |
BlockDriverAIOCB *file_acb; |
| 1088 |
|
| 1089 |
/* Adjust offset into cluster */
|
| 1090 |
offset += qed_offset_into_cluster(s, acb->cur_pos); |
| 1091 |
|
| 1092 |
trace_qed_aio_read_data(s, acb, ret, offset, len); |
| 1093 |
|
| 1094 |
if (ret < 0) { |
| 1095 |
goto err;
|
| 1096 |
} |
| 1097 |
|
| 1098 |
qemu_iovec_copy(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); |
| 1099 |
|
| 1100 |
/* Handle backing file and unallocated sparse hole reads */
|
| 1101 |
if (ret != QED_CLUSTER_FOUND) {
|
| 1102 |
qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, |
| 1103 |
qed_aio_next_io, acb); |
| 1104 |
return;
|
| 1105 |
} |
| 1106 |
|
| 1107 |
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
| 1108 |
file_acb = bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE, |
| 1109 |
&acb->cur_qiov, |
| 1110 |
acb->cur_qiov.size / BDRV_SECTOR_SIZE, |
| 1111 |
qed_aio_next_io, acb); |
| 1112 |
if (!file_acb) {
|
| 1113 |
ret = -EIO; |
| 1114 |
goto err;
|
| 1115 |
} |
| 1116 |
return;
|
| 1117 |
|
| 1118 |
err:
|
| 1119 |
qed_aio_complete(acb, ret); |
| 1120 |
} |
| 1121 |
|
| 1122 |
/**
|
| 1123 |
* Begin next I/O or complete the request
|
| 1124 |
*/
|
| 1125 |
static void qed_aio_next_io(void *opaque, int ret) |
| 1126 |
{
|
| 1127 |
QEDAIOCB *acb = opaque; |
| 1128 |
BDRVQEDState *s = acb_to_s(acb); |
| 1129 |
QEDFindClusterFunc *io_fn = |
| 1130 |
acb->is_write ? qed_aio_write_data : qed_aio_read_data; |
| 1131 |
|
| 1132 |
trace_qed_aio_next_io(s, acb, ret, acb->cur_pos + acb->cur_qiov.size); |
| 1133 |
|
| 1134 |
/* Handle I/O error */
|
| 1135 |
if (ret) {
|
| 1136 |
qed_aio_complete(acb, ret); |
| 1137 |
return;
|
| 1138 |
} |
| 1139 |
|
| 1140 |
acb->qiov_offset += acb->cur_qiov.size; |
| 1141 |
acb->cur_pos += acb->cur_qiov.size; |
| 1142 |
qemu_iovec_reset(&acb->cur_qiov); |
| 1143 |
|
| 1144 |
/* Complete request */
|
| 1145 |
if (acb->cur_pos >= acb->end_pos) {
|
| 1146 |
qed_aio_complete(acb, 0);
|
| 1147 |
return;
|
| 1148 |
} |
| 1149 |
|
| 1150 |
/* Find next cluster and start I/O */
|
| 1151 |
qed_find_cluster(s, &acb->request, |
| 1152 |
acb->cur_pos, acb->end_pos - acb->cur_pos, |
| 1153 |
io_fn, acb); |
| 1154 |
} |
| 1155 |
|
| 1156 |
static BlockDriverAIOCB *qed_aio_setup(BlockDriverState *bs,
|
| 1157 |
int64_t sector_num, |
| 1158 |
QEMUIOVector *qiov, int nb_sectors,
|
| 1159 |
BlockDriverCompletionFunc *cb, |
| 1160 |
void *opaque, bool is_write) |
| 1161 |
{
|
| 1162 |
QEDAIOCB *acb = qemu_aio_get(&qed_aio_pool, bs, cb, opaque); |
| 1163 |
|
| 1164 |
trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors, |
| 1165 |
opaque, is_write); |
| 1166 |
|
| 1167 |
acb->is_write = is_write; |
| 1168 |
acb->finished = NULL;
|
| 1169 |
acb->qiov = qiov; |
| 1170 |
acb->qiov_offset = 0;
|
| 1171 |
acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE; |
| 1172 |
acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE; |
| 1173 |
acb->request.l2_table = NULL;
|
| 1174 |
qemu_iovec_init(&acb->cur_qiov, qiov->niov); |
| 1175 |
|
| 1176 |
/* Start request */
|
| 1177 |
qed_aio_next_io(acb, 0);
|
| 1178 |
return &acb->common;
|
| 1179 |
} |
| 1180 |
|
| 1181 |
static BlockDriverAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs,
|
| 1182 |
int64_t sector_num, |
| 1183 |
QEMUIOVector *qiov, int nb_sectors,
|
| 1184 |
BlockDriverCompletionFunc *cb, |
| 1185 |
void *opaque)
|
| 1186 |
{
|
| 1187 |
return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, false); |
| 1188 |
} |
| 1189 |
|
| 1190 |
static BlockDriverAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs,
|
| 1191 |
int64_t sector_num, |
| 1192 |
QEMUIOVector *qiov, int nb_sectors,
|
| 1193 |
BlockDriverCompletionFunc *cb, |
| 1194 |
void *opaque)
|
| 1195 |
{
|
| 1196 |
return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, true); |
| 1197 |
} |
| 1198 |
|
| 1199 |
static BlockDriverAIOCB *bdrv_qed_aio_flush(BlockDriverState *bs,
|
| 1200 |
BlockDriverCompletionFunc *cb, |
| 1201 |
void *opaque)
|
| 1202 |
{
|
| 1203 |
return bdrv_aio_flush(bs->file, cb, opaque);
|
| 1204 |
} |
| 1205 |
|
| 1206 |
static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset) |
| 1207 |
{
|
| 1208 |
return -ENOTSUP;
|
| 1209 |
} |
| 1210 |
|
| 1211 |
static int64_t bdrv_qed_getlength(BlockDriverState *bs)
|
| 1212 |
{
|
| 1213 |
BDRVQEDState *s = bs->opaque; |
| 1214 |
return s->header.image_size;
|
| 1215 |
} |
| 1216 |
|
| 1217 |
static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
| 1218 |
{
|
| 1219 |
BDRVQEDState *s = bs->opaque; |
| 1220 |
|
| 1221 |
memset(bdi, 0, sizeof(*bdi)); |
| 1222 |
bdi->cluster_size = s->header.cluster_size; |
| 1223 |
return 0; |
| 1224 |
} |
| 1225 |
|
| 1226 |
static int bdrv_qed_change_backing_file(BlockDriverState *bs, |
| 1227 |
const char *backing_file, |
| 1228 |
const char *backing_fmt) |
| 1229 |
{
|
| 1230 |
BDRVQEDState *s = bs->opaque; |
| 1231 |
QEDHeader new_header, le_header; |
| 1232 |
void *buffer;
|
| 1233 |
size_t buffer_len, backing_file_len; |
| 1234 |
int ret;
|
| 1235 |
|
| 1236 |
/* Refuse to set backing filename if unknown compat feature bits are
|
| 1237 |
* active. If the image uses an unknown compat feature then we may not
|
| 1238 |
* know the layout of data following the header structure and cannot safely
|
| 1239 |
* add a new string.
|
| 1240 |
*/
|
| 1241 |
if (backing_file && (s->header.compat_features &
|
| 1242 |
~QED_COMPAT_FEATURE_MASK)) {
|
| 1243 |
return -ENOTSUP;
|
| 1244 |
} |
| 1245 |
|
| 1246 |
memcpy(&new_header, &s->header, sizeof(new_header));
|
| 1247 |
|
| 1248 |
new_header.features &= ~(QED_F_BACKING_FILE | |
| 1249 |
QED_F_BACKING_FORMAT_NO_PROBE); |
| 1250 |
|
| 1251 |
/* Adjust feature flags */
|
| 1252 |
if (backing_file) {
|
| 1253 |
new_header.features |= QED_F_BACKING_FILE; |
| 1254 |
|
| 1255 |
if (qed_fmt_is_raw(backing_fmt)) {
|
| 1256 |
new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; |
| 1257 |
} |
| 1258 |
} |
| 1259 |
|
| 1260 |
/* Calculate new header size */
|
| 1261 |
backing_file_len = 0;
|
| 1262 |
|
| 1263 |
if (backing_file) {
|
| 1264 |
backing_file_len = strlen(backing_file); |
| 1265 |
} |
| 1266 |
|
| 1267 |
buffer_len = sizeof(new_header);
|
| 1268 |
new_header.backing_filename_offset = buffer_len; |
| 1269 |
new_header.backing_filename_size = backing_file_len; |
| 1270 |
buffer_len += backing_file_len; |
| 1271 |
|
| 1272 |
/* Make sure we can rewrite header without failing */
|
| 1273 |
if (buffer_len > new_header.header_size * new_header.cluster_size) {
|
| 1274 |
return -ENOSPC;
|
| 1275 |
} |
| 1276 |
|
| 1277 |
/* Prepare new header */
|
| 1278 |
buffer = qemu_malloc(buffer_len); |
| 1279 |
|
| 1280 |
qed_header_cpu_to_le(&new_header, &le_header); |
| 1281 |
memcpy(buffer, &le_header, sizeof(le_header));
|
| 1282 |
buffer_len = sizeof(le_header);
|
| 1283 |
|
| 1284 |
memcpy(buffer + buffer_len, backing_file, backing_file_len); |
| 1285 |
buffer_len += backing_file_len; |
| 1286 |
|
| 1287 |
/* Write new header */
|
| 1288 |
ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len);
|
| 1289 |
qemu_free(buffer); |
| 1290 |
if (ret == 0) { |
| 1291 |
memcpy(&s->header, &new_header, sizeof(new_header));
|
| 1292 |
} |
| 1293 |
return ret;
|
| 1294 |
} |
| 1295 |
|
| 1296 |
static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result) |
| 1297 |
{
|
| 1298 |
BDRVQEDState *s = bs->opaque; |
| 1299 |
|
| 1300 |
return qed_check(s, result, false); |
| 1301 |
} |
| 1302 |
|
| 1303 |
static QEMUOptionParameter qed_create_options[] = {
|
| 1304 |
{
|
| 1305 |
.name = BLOCK_OPT_SIZE, |
| 1306 |
.type = OPT_SIZE, |
| 1307 |
.help = "Virtual disk size (in bytes)"
|
| 1308 |
}, {
|
| 1309 |
.name = BLOCK_OPT_BACKING_FILE, |
| 1310 |
.type = OPT_STRING, |
| 1311 |
.help = "File name of a base image"
|
| 1312 |
}, {
|
| 1313 |
.name = BLOCK_OPT_BACKING_FMT, |
| 1314 |
.type = OPT_STRING, |
| 1315 |
.help = "Image format of the base image"
|
| 1316 |
}, {
|
| 1317 |
.name = BLOCK_OPT_CLUSTER_SIZE, |
| 1318 |
.type = OPT_SIZE, |
| 1319 |
.help = "Cluster size (in bytes)"
|
| 1320 |
}, {
|
| 1321 |
.name = BLOCK_OPT_TABLE_SIZE, |
| 1322 |
.type = OPT_SIZE, |
| 1323 |
.help = "L1/L2 table size (in clusters)"
|
| 1324 |
}, |
| 1325 |
{ /* end of list */ }
|
| 1326 |
}; |
| 1327 |
|
| 1328 |
static BlockDriver bdrv_qed = {
|
| 1329 |
.format_name = "qed",
|
| 1330 |
.instance_size = sizeof(BDRVQEDState),
|
| 1331 |
.create_options = qed_create_options, |
| 1332 |
|
| 1333 |
.bdrv_probe = bdrv_qed_probe, |
| 1334 |
.bdrv_open = bdrv_qed_open, |
| 1335 |
.bdrv_close = bdrv_qed_close, |
| 1336 |
.bdrv_create = bdrv_qed_create, |
| 1337 |
.bdrv_flush = bdrv_qed_flush, |
| 1338 |
.bdrv_is_allocated = bdrv_qed_is_allocated, |
| 1339 |
.bdrv_make_empty = bdrv_qed_make_empty, |
| 1340 |
.bdrv_aio_readv = bdrv_qed_aio_readv, |
| 1341 |
.bdrv_aio_writev = bdrv_qed_aio_writev, |
| 1342 |
.bdrv_aio_flush = bdrv_qed_aio_flush, |
| 1343 |
.bdrv_truncate = bdrv_qed_truncate, |
| 1344 |
.bdrv_getlength = bdrv_qed_getlength, |
| 1345 |
.bdrv_get_info = bdrv_qed_get_info, |
| 1346 |
.bdrv_change_backing_file = bdrv_qed_change_backing_file, |
| 1347 |
.bdrv_check = bdrv_qed_check, |
| 1348 |
}; |
| 1349 |
|
| 1350 |
static void bdrv_qed_init(void) |
| 1351 |
{
|
| 1352 |
bdrv_register(&bdrv_qed); |
| 1353 |
} |
| 1354 |
|
| 1355 |
block_init(bdrv_qed_init); |