| Message ID | 1439279489-13338-5-git-send-email-wency@cn.fujitsu.com |
|---|---|
| State | New |
| Headers | show |
On 08/11/2015 01:51 AM, 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> > Reviewed-by: Alberto Garcia <berto@igalia.com> > --- > block/quorum.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 73 insertions(+), 2 deletions(-) > > diff --git a/block/quorum.c b/block/quorum.c > index 2f6c45f..1305086 100644 > --- a/block/quorum.c > +++ b/block/quorum.c > @@ -66,6 +66,9 @@ typedef struct QuorumVotes { > typedef struct BDRVQuorumState { > BlockDriverState **bs; /* children BlockDriverStates */ > int num_children; /* children count */ > + int max_children; /* The maximum children count, we need to reallocate > + * bs if num_children will larger than maximum. s/will/grows/ > @@ -995,6 +999,70 @@ static void quorum_attach_aio_context(BlockDriverState *bs, > } > } > > +static void quorum_add_child(BlockDriverState *bs, QDict *options, Error **errp) > +{ > + BDRVQuorumState *s = bs->opaque; > + int ret; > + Error *local_err = NULL; > + > + bdrv_drain(bs); > + > + if (s->num_children == s->max_children) { > + if (s->max_children >= INT_MAX) { > + error_setg(errp, "Too many children"); > + return; > + } > + > + s->bs = g_renew(BlockDriverState *, s->bs, s->max_children + 1); > + s->bs[s->num_children] = NULL; > + s->max_children += 1; why not use ++? > + } > + > + ret = bdrv_open_image(&s->bs[s->num_children], NULL, options, "child", bs, > + &child_format, false, &local_err); > + if (ret < 0) { > + error_propagate(errp, local_err); > + return; > + } > + s->num_children++; > +} > + > +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, > + Error **errp) > +{ > + BDRVQuorumState *s = bs->opaque; > + int i; > + > + for (i = 0; i < s->num_children; i++) { > + if (s->bs[i] == child_bs) { > + break; > + } > + } > + > + if (i == s->num_children) { > + error_setg(errp, "Invalid child"); > + return; > + } The previous patch already assert()ed that the child was present; can't this one just assert(i < s->num_children)? > + > + if (s->num_children <= s->threshold) { > + error_setg(errp, > + "The number of children cannot be lower than the vote threshold"); > + return; Might be nice to include the numeric value of that threshold in the error message. > + } > + > + if (s->num_children == 1) { > + error_setg(errp, "Cannot remove the last child"); > + return; > + } Isn't this dead code, as the vote threshold always has to be at least 1, so the previous 'if' already rejected an attempt to go lower than the threshold? > + > + bdrv_drain(bs); > + /* We can safely remove this child now */ > + memmove(&s->bs[i], &s->bs[i+1], (s->num_children - i - 1) * sizeof(void *)); Spaces around '+'. > + s->num_children--; > + s->bs[s->num_children] = NULL; > + bdrv_unref(child_bs); > +} > + > static void quorum_refresh_filename(BlockDriverState *bs) > { > BDRVQuorumState *s = bs->opaque; > @@ -1049,6 +1117,9 @@ 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, > }; > Overall seems reasonable.
On 09/01/2015 02:53 AM, Eric Blake wrote: > On 08/11/2015 01:51 AM, 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> >> Reviewed-by: Alberto Garcia <berto@igalia.com> >> --- >> block/quorum.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 73 insertions(+), 2 deletions(-) >> >> diff --git a/block/quorum.c b/block/quorum.c >> index 2f6c45f..1305086 100644 >> --- a/block/quorum.c >> +++ b/block/quorum.c >> @@ -66,6 +66,9 @@ typedef struct QuorumVotes { >> typedef struct BDRVQuorumState { >> BlockDriverState **bs; /* children BlockDriverStates */ >> int num_children; /* children count */ >> + int max_children; /* The maximum children count, we need to reallocate >> + * bs if num_children will larger than maximum. > > s/will/grows/ > > >> @@ -995,6 +999,70 @@ static void quorum_attach_aio_context(BlockDriverState *bs, >> } >> } >> >> +static void quorum_add_child(BlockDriverState *bs, QDict *options, Error **errp) >> +{ >> + BDRVQuorumState *s = bs->opaque; >> + int ret; >> + Error *local_err = NULL; >> + >> + bdrv_drain(bs); >> + >> + if (s->num_children == s->max_children) { >> + if (s->max_children >= INT_MAX) { >> + error_setg(errp, "Too many children"); >> + return; >> + } >> + >> + s->bs = g_renew(BlockDriverState *, s->bs, s->max_children + 1); >> + s->bs[s->num_children] = NULL; >> + s->max_children += 1; > > why not use ++? > >> + } >> + >> + ret = bdrv_open_image(&s->bs[s->num_children], NULL, options, "child", bs, >> + &child_format, false, &local_err); >> + if (ret < 0) { >> + error_propagate(errp, local_err); >> + return; >> + } >> + s->num_children++; >> +} >> + >> +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, >> + Error **errp) >> +{ >> + BDRVQuorumState *s = bs->opaque; >> + int i; >> + >> + for (i = 0; i < s->num_children; i++) { >> + if (s->bs[i] == child_bs) { >> + break; >> + } >> + } >> + >> + if (i == s->num_children) { >> + error_setg(errp, "Invalid child"); >> + return; >> + } > > The previous patch already assert()ed that the child was present; can't > this one just assert(i < s->num_children)? > >> + >> + if (s->num_children <= s->threshold) { >> + error_setg(errp, >> + "The number of children cannot be lower than the vote threshold"); >> + return; > > Might be nice to include the numeric value of that threshold in the > error message. > >> + } >> + >> + if (s->num_children == 1) { >> + error_setg(errp, "Cannot remove the last child"); >> + return; >> + } > > Isn't this dead code, as the vote threshold always has to be at least 1, > so the previous 'if' already rejected an attempt to go lower than the > threshold? Yes, the vote threshold has to be at least 1. But current codes have a bug, and vote threshold can be 0. The patch is queued in Max's tree. I will remove it in the later version. All other comments will be addressed in the next version. Thanks Wen Congyang > >> + >> + bdrv_drain(bs); >> + /* We can safely remove this child now */ >> + memmove(&s->bs[i], &s->bs[i+1], (s->num_children - i - 1) * sizeof(void *)); > > Spaces around '+'. > >> + s->num_children--; >> + s->bs[s->num_children] = NULL; >> + bdrv_unref(child_bs); >> +} >> + >> static void quorum_refresh_filename(BlockDriverState *bs) >> { >> BDRVQuorumState *s = bs->opaque; >> @@ -1049,6 +1117,9 @@ 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, >> }; >> > > Overall seems reasonable. >
diff --git a/block/quorum.c b/block/quorum.c index 2f6c45f..1305086 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -66,6 +66,9 @@ typedef struct QuorumVotes { typedef struct BDRVQuorumState { BlockDriverState **bs; /* children BlockDriverStates */ int num_children; /* children count */ + int max_children; /* The maximum children count, we need to reallocate + * bs if num_children will larger than maximum. + */ int threshold; /* if less than threshold children reads gave the * same result a quorum error occurs. */ @@ -874,9 +877,9 @@ 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; } @@ -925,6 +928,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, /* allocate the children BlockDriverState array */ s->bs = g_new0(BlockDriverState *, s->num_children); opened = g_new0(bool, s->num_children); + s->max_children = s->num_children; for (i = 0; i < s->num_children; i++) { char indexstr[32]; @@ -995,6 +999,70 @@ static void quorum_attach_aio_context(BlockDriverState *bs, } } +static void quorum_add_child(BlockDriverState *bs, QDict *options, Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + int ret; + Error *local_err = NULL; + + bdrv_drain(bs); + + if (s->num_children == s->max_children) { + if (s->max_children >= INT_MAX) { + error_setg(errp, "Too many children"); + return; + } + + s->bs = g_renew(BlockDriverState *, s->bs, s->max_children + 1); + s->bs[s->num_children] = NULL; + s->max_children += 1; + } + + ret = bdrv_open_image(&s->bs[s->num_children], NULL, options, "child", bs, + &child_format, false, &local_err); + if (ret < 0) { + error_propagate(errp, local_err); + return; + } + s->num_children++; +} + +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + int i; + + for (i = 0; i < s->num_children; i++) { + if (s->bs[i] == child_bs) { + break; + } + } + + if (i == s->num_children) { + error_setg(errp, "Invalid child"); + return; + } + + if (s->num_children <= s->threshold) { + error_setg(errp, + "The number of children cannot be lower than the vote threshold"); + return; + } + + if (s->num_children == 1) { + error_setg(errp, "Cannot remove the last child"); + return; + } + + bdrv_drain(bs); + /* We can safely remove this child now */ + memmove(&s->bs[i], &s->bs[i+1], (s->num_children - i - 1) * sizeof(void *)); + s->num_children--; + s->bs[s->num_children] = NULL; + bdrv_unref(child_bs); +} + static void quorum_refresh_filename(BlockDriverState *bs) { BDRVQuorumState *s = bs->opaque; @@ -1049,6 +1117,9 @@ 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, };