| Message ID | 1448604397-14975-3-git-send-email-wency@cn.fujitsu.com |
|---|---|
| State | New |
| Headers | show |
On 11/27/2015 02:06 PM, Wen Congyang wrote: > Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> > Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com> > Signed-off-by: Gonglei <arei.gonglei@huawei.com> > --- > block.c | 8 ++-- > block/quorum.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++- > include/block/block.h | 4 ++ > 3 files changed, 130 insertions(+), 6 deletions(-) > > diff --git a/block.c b/block.c > index 255a36e..bfc2be8 100644 > --- a/block.c > +++ b/block.c > @@ -1196,10 +1196,10 @@ static int bdrv_fill_options(QDict **options, const char *filename, > return 0; > } > > -static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, > - BlockDriverState *child_bs, > - const char *child_name, > - const BdrvChildRole *child_role) > +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, > + BlockDriverState *child_bs, > + const char *child_name, > + const BdrvChildRole *child_role) > { > BdrvChild *child = g_new(BdrvChild, 1); > *child = (BdrvChild) { > diff --git a/block/quorum.c b/block/quorum.c > index 2810e37..b7df14b 100644 > --- a/block/quorum.c > +++ b/block/quorum.c > @@ -23,6 +23,7 @@ > #include "qapi/qmp/qstring.h" > #include "qapi-event.h" > #include "crypto/hash.h" > +#include "qemu/bitmap.h" > > #define HASH_LENGTH 32 > > @@ -80,6 +81,8 @@ typedef struct BDRVQuorumState { > bool rewrite_corrupted;/* true if the driver must rewrite-on-read corrupted > * block if Quorum is reached. > */ > + unsigned long *index_bitmap; > + int bsize; > > QuorumReadPattern read_pattern; > } BDRVQuorumState; > @@ -875,9 +878,9 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, > ret = -EINVAL; > goto exit; > } > - if (s->num_children < 2) { > + if (s->num_children < 1) { > error_setg(&local_err, > - "Number of provided children must be greater than 1"); > + "Number of provided children must be 1 or more"); > ret = -EINVAL; > goto exit; > } > @@ -926,6 +929,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, > /* allocate the children array */ > s->children = g_new0(BdrvChild *, s->num_children); > opened = g_new0(bool, s->num_children); > + s->index_bitmap = bitmap_new(s->num_children); > > for (i = 0; i < s->num_children; i++) { > char indexstr[32]; > @@ -941,6 +945,8 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, > > opened[i] = true; > } > + bitmap_set(s->index_bitmap, 0, s->num_children); > + s->bsize = s->num_children; > > g_free(opened); > goto exit; > @@ -997,6 +1003,117 @@ static void quorum_attach_aio_context(BlockDriverState *bs, > } > } > > +static int get_new_child_index(BDRVQuorumState *s) > +{ > + int index; > + > + index = find_next_zero_bit(s->index_bitmap, s->bsize, 0); > + if (index < s->bsize) { > + return index; > + } > + > + if ((s->bsize % BITS_PER_LONG) == 0) { > + s->index_bitmap = bitmap_zero_extend(s->index_bitmap, s->bsize, > + s->bsize + 1); > + } > + > + return s->bsize++; > +} > + > +static void remove_child_index(BDRVQuorumState *s, int index) > +{ > + int last_index; > + long new_len; > + > + assert(index < s->bsize); > + > + clear_bit(index, s->index_bitmap); > + if (index < s->bsize - 1) { > + /* > + * The last bit is always set, and we don't clear > + * the last bit. > + */ > + return; > + } > + > + last_index = find_last_bit(s->index_bitmap, s->bsize); > + if (BITS_TO_LONGS(last_index + 1) == BITS_TO_LONGS(s->bsize)) { > + s->bsize = last_index + 1; > + return; > + } > + > + new_len = BITS_TO_LONGS(last_index + 1) * sizeof(unsigned long); > + s->index_bitmap = g_realloc(s->index_bitmap, new_len); > + s->bsize = last_index + 1; > +} > + > +static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, > + Error **errp) > +{ > + BDRVQuorumState *s = bs->opaque; > + BdrvChild *child; > + char indexstr[32]; > + int index = find_next_zero_bit(s->index_bitmap, s->bsize, 0); > + int ret; > + > + index = get_new_child_index(s); double assignment of 'index', remove the first one pls Thanks Li > + ret = snprintf(indexstr, 32, "children.%d", index); > + if (ret < 0 || ret >= 32) { > + error_setg(errp, "cannot generate child name"); > + return; > + } > + > + bdrv_drain(bs); > + > + assert(s->num_children <= INT_MAX / sizeof(BdrvChild *)); > + if (s->num_children == INT_MAX / sizeof(BdrvChild *)) { > + error_setg(errp, "Too many children"); > + return; > + } > + s->children = g_renew(BdrvChild *, s->children, s->num_children + 1); > + > + bdrv_ref(child_bs); > + child = bdrv_attach_child(bs, child_bs, indexstr, &child_format); > + s->children[s->num_children++] = child; > + set_bit(index, s->index_bitmap); > +} > + > +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, > + Error **errp) > +{ > + BDRVQuorumState *s = bs->opaque; > + BdrvChild *child; > + int i, index; > + > + for (i = 0; i < s->num_children; i++) { > + if (s->children[i]->bs == child_bs) { > + break; > + } > + } > + > + /* we have checked it in bdrv_del_child() */ > + assert(i < s->num_children); > + child = s->children[i]; > + > + if (s->num_children <= s->threshold) { > + error_setg(errp, > + "The number of children cannot be lower than the vote threshold %d", > + s->threshold); > + return; > + } > + > + /* child->name is "children.%d" */ > + index = atoi(child->name + 9); > + > + bdrv_drain(bs); > + /* We can safely remove this child now */ > + memmove(&s->children[i], &s->children[i + 1], > + (s->num_children - i - 1) * sizeof(void *)); > + s->children = g_renew(BdrvChild *, s->children, --s->num_children); > + remove_child_index(s, index); > + bdrv_unref_child(bs, child); > +} > + > static void quorum_refresh_filename(BlockDriverState *bs, QDict *options) > { > BDRVQuorumState *s = bs->opaque; > @@ -1052,6 +1169,9 @@ static BlockDriver bdrv_quorum = { > .bdrv_detach_aio_context = quorum_detach_aio_context, > .bdrv_attach_aio_context = quorum_attach_aio_context, > > + .bdrv_add_child = quorum_add_child, > + .bdrv_del_child = quorum_del_child, > + > .is_filter = true, > .bdrv_recurse_is_first_non_filter = quorum_recurse_is_first_non_filter, > }; > diff --git a/include/block/block.h b/include/block/block.h > index 06d3369..1d3b9c6 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -514,6 +514,10 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs); > void bdrv_ref(BlockDriverState *bs); > void bdrv_unref(BlockDriverState *bs); > void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); > +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, > + BlockDriverState *child_bs, > + const char *child_name, > + const BdrvChildRole *child_role); > > bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); > void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason); >
diff --git a/block.c b/block.c index 255a36e..bfc2be8 100644 --- a/block.c +++ b/block.c @@ -1196,10 +1196,10 @@ static int bdrv_fill_options(QDict **options, const char *filename, return 0; } -static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, - BlockDriverState *child_bs, - const char *child_name, - const BdrvChildRole *child_role) +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, + BlockDriverState *child_bs, + const char *child_name, + const BdrvChildRole *child_role) { BdrvChild *child = g_new(BdrvChild, 1); *child = (BdrvChild) { diff --git a/block/quorum.c b/block/quorum.c index 2810e37..b7df14b 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -23,6 +23,7 @@ #include "qapi/qmp/qstring.h" #include "qapi-event.h" #include "crypto/hash.h" +#include "qemu/bitmap.h" #define HASH_LENGTH 32 @@ -80,6 +81,8 @@ typedef struct BDRVQuorumState { bool rewrite_corrupted;/* true if the driver must rewrite-on-read corrupted * block if Quorum is reached. */ + unsigned long *index_bitmap; + int bsize; QuorumReadPattern read_pattern; } BDRVQuorumState; @@ -875,9 +878,9 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, ret = -EINVAL; goto exit; } - if (s->num_children < 2) { + if (s->num_children < 1) { error_setg(&local_err, - "Number of provided children must be greater than 1"); + "Number of provided children must be 1 or more"); ret = -EINVAL; goto exit; } @@ -926,6 +929,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, /* allocate the children array */ s->children = g_new0(BdrvChild *, s->num_children); opened = g_new0(bool, s->num_children); + s->index_bitmap = bitmap_new(s->num_children); for (i = 0; i < s->num_children; i++) { char indexstr[32]; @@ -941,6 +945,8 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, opened[i] = true; } + bitmap_set(s->index_bitmap, 0, s->num_children); + s->bsize = s->num_children; g_free(opened); goto exit; @@ -997,6 +1003,117 @@ static void quorum_attach_aio_context(BlockDriverState *bs, } } +static int get_new_child_index(BDRVQuorumState *s) +{ + int index; + + index = find_next_zero_bit(s->index_bitmap, s->bsize, 0); + if (index < s->bsize) { + return index; + } + + if ((s->bsize % BITS_PER_LONG) == 0) { + s->index_bitmap = bitmap_zero_extend(s->index_bitmap, s->bsize, + s->bsize + 1); + } + + return s->bsize++; +} + +static void remove_child_index(BDRVQuorumState *s, int index) +{ + int last_index; + long new_len; + + assert(index < s->bsize); + + clear_bit(index, s->index_bitmap); + if (index < s->bsize - 1) { + /* + * The last bit is always set, and we don't clear + * the last bit. + */ + return; + } + + last_index = find_last_bit(s->index_bitmap, s->bsize); + if (BITS_TO_LONGS(last_index + 1) == BITS_TO_LONGS(s->bsize)) { + s->bsize = last_index + 1; + return; + } + + new_len = BITS_TO_LONGS(last_index + 1) * sizeof(unsigned long); + s->index_bitmap = g_realloc(s->index_bitmap, new_len); + s->bsize = last_index + 1; +} + +static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + BdrvChild *child; + char indexstr[32]; + int index = find_next_zero_bit(s->index_bitmap, s->bsize, 0); + int ret; + + index = get_new_child_index(s); + ret = snprintf(indexstr, 32, "children.%d", index); + if (ret < 0 || ret >= 32) { + error_setg(errp, "cannot generate child name"); + return; + } + + bdrv_drain(bs); + + assert(s->num_children <= INT_MAX / sizeof(BdrvChild *)); + if (s->num_children == INT_MAX / sizeof(BdrvChild *)) { + error_setg(errp, "Too many children"); + return; + } + s->children = g_renew(BdrvChild *, s->children, s->num_children + 1); + + bdrv_ref(child_bs); + child = bdrv_attach_child(bs, child_bs, indexstr, &child_format); + s->children[s->num_children++] = child; + set_bit(index, s->index_bitmap); +} + +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + BdrvChild *child; + int i, index; + + for (i = 0; i < s->num_children; i++) { + if (s->children[i]->bs == child_bs) { + break; + } + } + + /* we have checked it in bdrv_del_child() */ + assert(i < s->num_children); + child = s->children[i]; + + if (s->num_children <= s->threshold) { + error_setg(errp, + "The number of children cannot be lower than the vote threshold %d", + s->threshold); + return; + } + + /* child->name is "children.%d" */ + index = atoi(child->name + 9); + + bdrv_drain(bs); + /* We can safely remove this child now */ + memmove(&s->children[i], &s->children[i + 1], + (s->num_children - i - 1) * sizeof(void *)); + s->children = g_renew(BdrvChild *, s->children, --s->num_children); + remove_child_index(s, index); + bdrv_unref_child(bs, child); +} + static void quorum_refresh_filename(BlockDriverState *bs, QDict *options) { BDRVQuorumState *s = bs->opaque; @@ -1052,6 +1169,9 @@ static BlockDriver bdrv_quorum = { .bdrv_detach_aio_context = quorum_detach_aio_context, .bdrv_attach_aio_context = quorum_attach_aio_context, + .bdrv_add_child = quorum_add_child, + .bdrv_del_child = quorum_del_child, + .is_filter = true, .bdrv_recurse_is_first_non_filter = quorum_recurse_is_first_non_filter, }; diff --git a/include/block/block.h b/include/block/block.h index 06d3369..1d3b9c6 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -514,6 +514,10 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs); void bdrv_ref(BlockDriverState *bs); void bdrv_unref(BlockDriverState *bs); void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, + BlockDriverState *child_bs, + const char *child_name, + const BdrvChildRole *child_role); bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);