| Message ID | 1492838021-10538-5-git-send-email-ashijeetacharya@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 04/22 10:43, Ashijeet Acharya wrote: > Move the cluster tables loading code out of the existing > vmdk_get_cluster_offset() function and implement it in separate > get_cluster_table() and vmdk_L2load() functions. This patch will help Now vmdk_L2load is in lower case, "vmdk_l2load". > us avoid code duplication in future patches of this series. Bikeshedding: "of this series" is meaningful now, but not quite so once this patch becomes a commit in qemu.git - the series information will be missing. > > Signed-off-by: Ashijeet Acharya <ashijeetacharya@gmail.com> > --- > block/vmdk.c | 153 ++++++++++++++++++++++++++++++++++++++++------------------- > 1 file changed, 105 insertions(+), 48 deletions(-) > > diff --git a/block/vmdk.c b/block/vmdk.c > index f403981..4cee868 100644 > --- a/block/vmdk.c > +++ b/block/vmdk.c > @@ -1143,6 +1143,105 @@ static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data, > return VMDK_OK; > } > > +/* > + * vmdk_l2load > + * > + * Load a new L2 table into memory. If the table is in the cache, the cache > + * is used; otherwise the L2 table is loaded from the image file. > + * > + * Returns: > + * VMDK_OK: on success > + * VMDK_ERROR: in error cases > + */ > +static int vmdk_l2load(VmdkExtent *extent, uint64_t offset, int l2_offset, > + uint32_t **new_l2_table, int *new_l2_index) > +{ > + int min_index, i, j; > + uint32_t *l2_table; > + uint32_t min_count; > + > + for (i = 0; i < L2_CACHE_SIZE; i++) { > + if (l2_offset == extent->l2_cache_offsets[i]) { > + /* increment the hit count */ > + if (++extent->l2_cache_counts[i] == UINT32_MAX) { > + for (j = 0; j < L2_CACHE_SIZE; j++) { > + extent->l2_cache_counts[j] >>= 1; > + } > + } > + l2_table = extent->l2_cache + (i * extent->l2_size); > + goto found; > + } > + } > + /* not found: load a new entry in the least used one */ > + min_index = 0; > + min_count = UINT32_MAX; > + for (i = 0; i < L2_CACHE_SIZE; i++) { > + if (extent->l2_cache_counts[i] < min_count) { > + min_count = extent->l2_cache_counts[i]; > + min_index = i; > + } > + } > + l2_table = extent->l2_cache + (min_index * extent->l2_size); > + if (bdrv_pread(extent->file, > + (int64_t)l2_offset * 512, > + l2_table, > + extent->l2_size * sizeof(uint32_t) > + ) != extent->l2_size * sizeof(uint32_t)) { > + return VMDK_ERROR; > + } > + > + extent->l2_cache_offsets[min_index] = l2_offset; > + extent->l2_cache_counts[min_index] = 1; > +found: > + *new_l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size; > + *new_l2_table = l2_table; > + > + return VMDK_OK; > +} > + > +/* > + * get_cluster_table > + * > + * for a given offset, load (and allocate if needed) the l2 table. More consistent if you capitalize the first letter "For". > + * > + * Returns: > + * VMDK_OK: on success > + * > + * VMDK_UNALLOC: if cluster is not mapped > + * > + * VMDK_ERROR: in error cases > + */ > +static int get_cluster_table(VmdkExtent *extent, uint64_t offset, > + int *new_l1_index, int *new_l2_offset, > + int *new_l2_index, uint32_t **new_l2_table) > +{ > + int l1_index, l2_offset, l2_index; > + uint32_t *l2_table; > + int ret; > + > + offset -= (extent->end_sector - extent->sectors) * SECTOR_SIZE; > + l1_index = (offset >> 9) / extent->l1_entry_sectors; > + if (l1_index >= extent->l1_size) { > + return VMDK_ERROR; > + } > + l2_offset = extent->l1_table[l1_index]; > + if (!l2_offset) { > + return VMDK_UNALLOC; > + } > + > + ret = vmdk_l2load(extent, offset, l2_offset, &l2_table, &l2_index); > + if (ret < 0) { > + return ret; > + } > + > + *new_l1_index = l1_index; > + *new_l2_offset = l2_offset; > + *new_l2_index = l2_index; > + *new_l2_table = l2_table; > + > + return VMDK_OK; > +} > + > /** > * vmdk_get_cluster_offset > * > @@ -1172,66 +1271,24 @@ static int vmdk_get_cluster_offset(BlockDriverState *bs, > uint64_t skip_start_bytes, > uint64_t skip_end_bytes) > { > - unsigned int l1_index, l2_offset, l2_index; > - int min_index, i, j; > - uint32_t min_count, *l2_table; > + int l1_index, l2_offset, l2_index; > + uint32_t *l2_table; > bool zeroed = false; > int64_t ret; > int64_t cluster_sector; > > - if (m_data) { > - m_data->valid = 0; > - } > if (extent->flat) { > *cluster_offset = extent->flat_start_offset; > return VMDK_OK; > } > > - offset -= (extent->end_sector - extent->sectors) * SECTOR_SIZE; > - l1_index = (offset >> 9) / extent->l1_entry_sectors; > - if (l1_index >= extent->l1_size) { > - return VMDK_ERROR; > - } > - l2_offset = extent->l1_table[l1_index]; > - if (!l2_offset) { > - return VMDK_UNALLOC; > - } > - for (i = 0; i < L2_CACHE_SIZE; i++) { > - if (l2_offset == extent->l2_cache_offsets[i]) { > - /* increment the hit count */ > - if (++extent->l2_cache_counts[i] == 0xffffffff) { > - for (j = 0; j < L2_CACHE_SIZE; j++) { > - extent->l2_cache_counts[j] >>= 1; > - } > - } > - l2_table = extent->l2_cache + (i * extent->l2_size); > - goto found; > - } > - } > - /* not found: load a new entry in the least used one */ > - min_index = 0; > - min_count = 0xffffffff; > - for (i = 0; i < L2_CACHE_SIZE; i++) { > - if (extent->l2_cache_counts[i] < min_count) { > - min_count = extent->l2_cache_counts[i]; > - min_index = i; > - } > - } > - l2_table = extent->l2_cache + (min_index * extent->l2_size); > - if (bdrv_pread(extent->file, > - (int64_t)l2_offset * 512, > - l2_table, > - extent->l2_size * sizeof(uint32_t) > - ) != extent->l2_size * sizeof(uint32_t)) { > - return VMDK_ERROR; > + ret = get_cluster_table(extent, offset, &l1_index, &l2_offset, > + &l2_index, &l2_table); > + if (ret < 0) { > + return ret; > } > > - extent->l2_cache_offsets[min_index] = l2_offset; > - extent->l2_cache_counts[min_index] = 1; > - found: > - l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size; > cluster_sector = le32_to_cpu(l2_table[l2_index]); > - > if (extent->has_zero_grain && cluster_sector == VMDK_GTE_ZEROED) { > zeroed = true; > } > -- > 2.6.2 > Apart from the cosmetic nits: Reviewed-by: Fam Zheng <famz@redhat.com>
diff --git a/block/vmdk.c b/block/vmdk.c index f403981..4cee868 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -1143,6 +1143,105 @@ static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data, return VMDK_OK; } +/* + * vmdk_l2load + * + * Load a new L2 table into memory. If the table is in the cache, the cache + * is used; otherwise the L2 table is loaded from the image file. + * + * Returns: + * VMDK_OK: on success + * VMDK_ERROR: in error cases + */ +static int vmdk_l2load(VmdkExtent *extent, uint64_t offset, int l2_offset, + uint32_t **new_l2_table, int *new_l2_index) +{ + int min_index, i, j; + uint32_t *l2_table; + uint32_t min_count; + + for (i = 0; i < L2_CACHE_SIZE; i++) { + if (l2_offset == extent->l2_cache_offsets[i]) { + /* increment the hit count */ + if (++extent->l2_cache_counts[i] == UINT32_MAX) { + for (j = 0; j < L2_CACHE_SIZE; j++) { + extent->l2_cache_counts[j] >>= 1; + } + } + l2_table = extent->l2_cache + (i * extent->l2_size); + goto found; + } + } + /* not found: load a new entry in the least used one */ + min_index = 0; + min_count = UINT32_MAX; + for (i = 0; i < L2_CACHE_SIZE; i++) { + if (extent->l2_cache_counts[i] < min_count) { + min_count = extent->l2_cache_counts[i]; + min_index = i; + } + } + l2_table = extent->l2_cache + (min_index * extent->l2_size); + if (bdrv_pread(extent->file, + (int64_t)l2_offset * 512, + l2_table, + extent->l2_size * sizeof(uint32_t) + ) != extent->l2_size * sizeof(uint32_t)) { + return VMDK_ERROR; + } + + extent->l2_cache_offsets[min_index] = l2_offset; + extent->l2_cache_counts[min_index] = 1; +found: + *new_l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size; + *new_l2_table = l2_table; + + return VMDK_OK; +} + +/* + * get_cluster_table + * + * for a given offset, load (and allocate if needed) the l2 table. + * + * Returns: + * VMDK_OK: on success + * + * VMDK_UNALLOC: if cluster is not mapped + * + * VMDK_ERROR: in error cases + */ +static int get_cluster_table(VmdkExtent *extent, uint64_t offset, + int *new_l1_index, int *new_l2_offset, + int *new_l2_index, uint32_t **new_l2_table) +{ + int l1_index, l2_offset, l2_index; + uint32_t *l2_table; + int ret; + + offset -= (extent->end_sector - extent->sectors) * SECTOR_SIZE; + l1_index = (offset >> 9) / extent->l1_entry_sectors; + if (l1_index >= extent->l1_size) { + return VMDK_ERROR; + } + l2_offset = extent->l1_table[l1_index]; + if (!l2_offset) { + return VMDK_UNALLOC; + } + + ret = vmdk_l2load(extent, offset, l2_offset, &l2_table, &l2_index); + if (ret < 0) { + return ret; + } + + *new_l1_index = l1_index; + *new_l2_offset = l2_offset; + *new_l2_index = l2_index; + *new_l2_table = l2_table; + + return VMDK_OK; +} + /** * vmdk_get_cluster_offset * @@ -1172,66 +1271,24 @@ static int vmdk_get_cluster_offset(BlockDriverState *bs, uint64_t skip_start_bytes, uint64_t skip_end_bytes) { - unsigned int l1_index, l2_offset, l2_index; - int min_index, i, j; - uint32_t min_count, *l2_table; + int l1_index, l2_offset, l2_index; + uint32_t *l2_table; bool zeroed = false; int64_t ret; int64_t cluster_sector; - if (m_data) { - m_data->valid = 0; - } if (extent->flat) { *cluster_offset = extent->flat_start_offset; return VMDK_OK; } - offset -= (extent->end_sector - extent->sectors) * SECTOR_SIZE; - l1_index = (offset >> 9) / extent->l1_entry_sectors; - if (l1_index >= extent->l1_size) { - return VMDK_ERROR; - } - l2_offset = extent->l1_table[l1_index]; - if (!l2_offset) { - return VMDK_UNALLOC; - } - for (i = 0; i < L2_CACHE_SIZE; i++) { - if (l2_offset == extent->l2_cache_offsets[i]) { - /* increment the hit count */ - if (++extent->l2_cache_counts[i] == 0xffffffff) { - for (j = 0; j < L2_CACHE_SIZE; j++) { - extent->l2_cache_counts[j] >>= 1; - } - } - l2_table = extent->l2_cache + (i * extent->l2_size); - goto found; - } - } - /* not found: load a new entry in the least used one */ - min_index = 0; - min_count = 0xffffffff; - for (i = 0; i < L2_CACHE_SIZE; i++) { - if (extent->l2_cache_counts[i] < min_count) { - min_count = extent->l2_cache_counts[i]; - min_index = i; - } - } - l2_table = extent->l2_cache + (min_index * extent->l2_size); - if (bdrv_pread(extent->file, - (int64_t)l2_offset * 512, - l2_table, - extent->l2_size * sizeof(uint32_t) - ) != extent->l2_size * sizeof(uint32_t)) { - return VMDK_ERROR; + ret = get_cluster_table(extent, offset, &l1_index, &l2_offset, + &l2_index, &l2_table); + if (ret < 0) { + return ret; } - extent->l2_cache_offsets[min_index] = l2_offset; - extent->l2_cache_counts[min_index] = 1; - found: - l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size; cluster_sector = le32_to_cpu(l2_table[l2_index]); - if (extent->has_zero_grain && cluster_sector == VMDK_GTE_ZEROED) { zeroed = true; }
Move the cluster tables loading code out of the existing vmdk_get_cluster_offset() function and implement it in separate get_cluster_table() and vmdk_L2load() functions. This patch will help us avoid code duplication in future patches of this series. Signed-off-by: Ashijeet Acharya <ashijeetacharya@gmail.com> --- block/vmdk.c | 153 ++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 105 insertions(+), 48 deletions(-)