Divide get_cluster_offset() (Laurent Vivier)
Divide get_cluster_offset() into get_cluster_offset() and alloc_cluster_offset(). Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5004 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aliguori
parent
108534b968
commit
052035244f
212
block-qcow2.c
212
block-qcow2.c
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@ -606,22 +606,77 @@ static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index)
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return l2_table;
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}
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static uint64_t get_cluster_offset(BlockDriverState *bs,
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uint64_t offset, int allocate,
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int compressed_size,
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int n_start, int n_end)
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/*
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* get_cluster_offset
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*
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* For a given offset of the disk image, return cluster offset in
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* qcow2 file.
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*
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* Return 1, if the offset is found
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* Return 0, otherwise.
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*
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*/
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static uint64_t get_cluster_offset(BlockDriverState *bs, uint64_t offset)
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{
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BDRVQcowState *s = bs->opaque;
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int l1_index, l2_index;
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uint64_t l2_offset, *l2_table, cluster_offset;
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/* seek the the l2 offset in the l1 table */
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l1_index = offset >> (s->l2_bits + s->cluster_bits);
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if (l1_index >= s->l1_size)
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return 0;
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l2_offset = s->l1_table[l1_index];
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/* seek the l2 table of the given l2 offset */
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if (!l2_offset)
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return 0;
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/* load the l2 table in memory */
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l2_offset &= ~QCOW_OFLAG_COPIED;
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l2_table = l2_load(bs, l2_offset);
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if (l2_table == NULL)
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return 0;
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/* find the cluster offset for the given disk offset */
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l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
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cluster_offset = be64_to_cpu(l2_table[l2_index]);
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return cluster_offset & ~QCOW_OFLAG_COPIED;
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}
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/*
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* alloc_cluster_offset
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*
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* For a given offset of the disk image, return cluster offset in
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* qcow2 file.
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*
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* If the offset is not found, allocate a new cluster.
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*
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* Return the cluster offset if successful,
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* Return 0, otherwise.
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*
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*/
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static uint64_t alloc_cluster_offset(BlockDriverState *bs,
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uint64_t offset,
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int compressed_size,
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int n_start, int n_end)
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{
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BDRVQcowState *s = bs->opaque;
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int l1_index, l2_index, ret;
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uint64_t l2_offset, *l2_table, cluster_offset, tmp;
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uint64_t l2_offset, *l2_table, cluster_offset;
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/* seek the the l2 offset in the l1 table */
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l1_index = offset >> (s->l2_bits + s->cluster_bits);
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if (l1_index >= s->l1_size) {
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/* outside l1 table is allowed: we grow the table if needed */
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if (!allocate)
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return 0;
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ret = grow_l1_table(bs, l1_index + 1);
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if (ret < 0)
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return 0;
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@ -630,44 +685,30 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
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/* seek the l2 table of the given l2 offset */
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if (!l2_offset) {
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/* the l2 table doesn't exist */
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if (!allocate)
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if (l2_offset & QCOW_OFLAG_COPIED) {
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/* load the l2 table in memory */
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l2_offset &= ~QCOW_OFLAG_COPIED;
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l2_table = l2_load(bs, l2_offset);
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if (l2_table == NULL)
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return 0;
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/* allocate a new l2 table for this offset */
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} else {
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if (l2_offset)
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free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
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l2_table = l2_allocate(bs, l1_index);
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if (l2_table == NULL)
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return 0;
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l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED;
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} else {
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/* the l2 table exists */
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if (!(l2_offset & QCOW_OFLAG_COPIED) && allocate) {
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/* duplicate the l2 table, and free the old table */
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free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
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l2_table = l2_allocate(bs, l1_index);
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if (l2_table == NULL)
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return 0;
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l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED;
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} else {
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/* load the l2 table in memory */
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l2_offset &= ~QCOW_OFLAG_COPIED;
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l2_table = l2_load(bs, l2_offset);
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if (l2_table == NULL)
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return 0;
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}
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}
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/* find the cluster offset for the given disk offset */
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l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
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cluster_offset = be64_to_cpu(l2_table[l2_index]);
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if (!cluster_offset) {
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/* cluster doesn't exist */
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if (!allocate)
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return 0;
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} else if (!(cluster_offset & QCOW_OFLAG_COPIED)) {
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if (!allocate)
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return cluster_offset;
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if (cluster_offset & QCOW_OFLAG_COPIED)
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return cluster_offset & ~QCOW_OFLAG_COPIED;
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if (cluster_offset) {
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/* free the cluster */
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if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
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int nb_csectors;
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@ -678,46 +719,62 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
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} else {
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free_clusters(bs, cluster_offset, s->cluster_size);
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}
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} else {
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cluster_offset &= ~QCOW_OFLAG_COPIED;
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}
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if (compressed_size) {
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int nb_csectors;
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cluster_offset = alloc_bytes(bs, compressed_size);
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nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
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(cluster_offset >> 9);
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cluster_offset |= QCOW_OFLAG_COMPRESSED |
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((uint64_t)nb_csectors << s->csize_shift);
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/* update L2 table */
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/* compressed clusters never have the copied flag */
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l2_table[l2_index] = cpu_to_be64(cluster_offset);
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if (bdrv_pwrite(s->hd,
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l2_offset + l2_index * sizeof(uint64_t),
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l2_table + l2_index,
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sizeof(uint64_t)) != sizeof(uint64_t))
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return 0;
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return cluster_offset;
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}
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if (allocate == 1) {
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/* allocate a new cluster */
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cluster_offset = alloc_clusters(bs, s->cluster_size);
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/* allocate a new cluster */
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/* we must initialize the cluster content which won't be
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written */
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if ((n_end - n_start) < s->cluster_sectors) {
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uint64_t start_sect;
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cluster_offset = alloc_clusters(bs, s->cluster_size);
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start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
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ret = copy_sectors(bs, start_sect,
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cluster_offset, 0, n_start);
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if (ret < 0)
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return 0;
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ret = copy_sectors(bs, start_sect,
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cluster_offset, n_end, s->cluster_sectors);
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if (ret < 0)
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return 0;
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}
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tmp = cpu_to_be64(cluster_offset | QCOW_OFLAG_COPIED);
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} else {
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int nb_csectors;
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cluster_offset = alloc_bytes(bs, compressed_size);
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nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
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(cluster_offset >> 9);
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cluster_offset |= QCOW_OFLAG_COMPRESSED |
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((uint64_t)nb_csectors << s->csize_shift);
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/* compressed clusters never have the copied flag */
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tmp = cpu_to_be64(cluster_offset);
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/* we must initialize the cluster content which won't be
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written */
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if ((n_end - n_start) < s->cluster_sectors) {
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uint64_t start_sect;
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start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
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ret = copy_sectors(bs, start_sect,
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cluster_offset, 0, n_start);
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if (ret < 0)
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return 0;
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ret = copy_sectors(bs, start_sect,
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cluster_offset, n_end, s->cluster_sectors);
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if (ret < 0)
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return 0;
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}
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/* update L2 table */
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l2_table[l2_index] = tmp;
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l2_table[l2_index] = cpu_to_be64(cluster_offset | QCOW_OFLAG_COPIED);
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if (bdrv_pwrite(s->hd,
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l2_offset + l2_index * sizeof(tmp), &tmp, sizeof(tmp)) != sizeof(tmp))
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l2_offset + l2_index * sizeof(uint64_t),
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l2_table + l2_index,
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sizeof(uint64_t)) != sizeof(uint64_t))
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return 0;
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return cluster_offset;
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}
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@ -728,7 +785,7 @@ static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
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int index_in_cluster, n;
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uint64_t cluster_offset;
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cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
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cluster_offset = get_cluster_offset(bs, sector_num << 9);
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index_in_cluster = sector_num & (s->cluster_sectors - 1);
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n = s->cluster_sectors - index_in_cluster;
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if (n > nb_sectors)
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@ -810,7 +867,7 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num,
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uint64_t cluster_offset;
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while (nb_sectors > 0) {
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cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
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cluster_offset = get_cluster_offset(bs, sector_num << 9);
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index_in_cluster = sector_num & (s->cluster_sectors - 1);
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n = s->cluster_sectors - index_in_cluster;
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if (n > nb_sectors)
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@ -859,9 +916,9 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num,
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n = s->cluster_sectors - index_in_cluster;
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if (n > nb_sectors)
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n = nb_sectors;
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cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0,
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index_in_cluster,
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index_in_cluster + n);
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cluster_offset = alloc_cluster_offset(bs, sector_num << 9, 0,
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index_in_cluster,
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index_in_cluster + n);
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if (!cluster_offset)
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return -1;
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if (s->crypt_method) {
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@ -934,8 +991,7 @@ static void qcow_aio_read_cb(void *opaque, int ret)
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}
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/* prepare next AIO request */
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acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9,
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0, 0, 0, 0);
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acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9);
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index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
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acb->n = s->cluster_sectors - index_in_cluster;
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if (acb->n > acb->nb_sectors)
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@ -1044,9 +1100,9 @@ static void qcow_aio_write_cb(void *opaque, int ret)
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acb->n = s->cluster_sectors - index_in_cluster;
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if (acb->n > acb->nb_sectors)
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acb->n = acb->nb_sectors;
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cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0,
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index_in_cluster,
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index_in_cluster + acb->n);
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cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9, 0,
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index_in_cluster,
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index_in_cluster + acb->n);
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if (!cluster_offset || (cluster_offset & 511) != 0) {
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ret = -EIO;
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goto fail;
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@ -1306,8 +1362,8 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
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/* could not compress: write normal cluster */
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qcow_write(bs, sector_num, buf, s->cluster_sectors);
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} else {
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cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
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out_len, 0, 0);
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cluster_offset = alloc_cluster_offset(bs, sector_num << 9,
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out_len, 0, 0);
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cluster_offset &= s->cluster_offset_mask;
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if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
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qemu_free(out_buf);
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