| Message ID | 20200909185930.26524-11-vsementsov@virtuozzo.com |
|---|---|
| State | New |
| Headers | show |
| Series | block: deal with errp: part I | expand |
On Wed 09 Sep 2020 08:59:26 PM CEST, Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> wrote: > -/* qcow2_load_dirty_bitmaps() > - * Return value is a hint for caller: true means that the Qcow2 header was > - * updated. (false doesn't mean that the header should be updated by the > - * caller, it just means that updating was not needed or the image cannot be > - * written to). > - * On failure the function returns false. > - */ > -bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) > +/* Return true on success, false on failure. */ > +bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated, > + Error **errp) I think that the documentation should clarify under what conditions 'header_updated' is modified. > if (s->nb_bitmaps == 0) { > /* No bitmaps - nothing to do */ > - return false; > + return true; > } Here is it not for example (should it be set to false?). > - if (bm_list == NULL) { > + if (!bm_list) { > return false; > } This looks like a cosmetic change unrelated to the rest of the patch. Berto
17.09.2020 19:35, Alberto Garcia wrote: > On Wed 09 Sep 2020 08:59:26 PM CEST, Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> wrote: >> -/* qcow2_load_dirty_bitmaps() >> - * Return value is a hint for caller: true means that the Qcow2 header was >> - * updated. (false doesn't mean that the header should be updated by the >> - * caller, it just means that updating was not needed or the image cannot be >> - * written to). >> - * On failure the function returns false. >> - */ >> -bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) >> +/* Return true on success, false on failure. */ >> +bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated, >> + Error **errp) > > I think that the documentation should clarify under what conditions > 'header_updated' is modified. > >> if (s->nb_bitmaps == 0) { >> /* No bitmaps - nothing to do */ >> - return false; >> + return true; >> } > > Here is it not for example (should it be set to false?). Ha, I think, it just shows that patch is wrong :) We should set header_updated at least on every success path. Or better always (if it is non-NULL of course). Thanks for careful review! > >> - if (bm_list == NULL) { >> + if (!bm_list) { >> return false; >> } > > This looks like a cosmetic change unrelated to the rest of the patch. > > Berto >
diff --git a/block/qcow2.h b/block/qcow2.h index ac6a2d3e2a..e7e662533b 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -966,7 +966,8 @@ void qcow2_cache_discard(Qcow2Cache *c, void *table); int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, void **refcount_table, int64_t *refcount_table_size); -bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp); +bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated, + Error **errp); bool qcow2_get_bitmap_info_list(BlockDriverState *bs, Qcow2BitmapInfoList **info_list, Error **errp); int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp); diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 9b14c0791f..f58923fce3 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -959,30 +959,24 @@ static void set_readonly_helper(gpointer bitmap, gpointer value) bdrv_dirty_bitmap_set_readonly(bitmap, (bool)value); } -/* qcow2_load_dirty_bitmaps() - * Return value is a hint for caller: true means that the Qcow2 header was - * updated. (false doesn't mean that the header should be updated by the - * caller, it just means that updating was not needed or the image cannot be - * written to). - * On failure the function returns false. - */ -bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) +/* Return true on success, false on failure. */ +bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated, + Error **errp) { BDRVQcow2State *s = bs->opaque; Qcow2BitmapList *bm_list; Qcow2Bitmap *bm; GSList *created_dirty_bitmaps = NULL; - bool header_updated = false; bool needs_update = false; if (s->nb_bitmaps == 0) { /* No bitmaps - nothing to do */ - return false; + return true; } bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, s->bitmap_directory_size, errp); - if (bm_list == NULL) { + if (!bm_list) { return false; } @@ -1033,7 +1027,9 @@ bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) error_setg_errno(errp, -ret, "Can't update bitmap directory"); goto fail; } - header_updated = true; + if (header_updated) { + *header_updated = true; + } } if (!can_write(bs)) { @@ -1044,7 +1040,7 @@ bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) g_slist_free(created_dirty_bitmaps); bitmap_list_free(bm_list); - return header_updated; + return true; fail: g_slist_foreach(created_dirty_bitmaps, release_dirty_bitmap_helper, bs); diff --git a/block/qcow2.c b/block/qcow2.c index eb7c82120c..c2cd9434cc 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1297,7 +1297,6 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, unsigned int len, i; int ret = 0; QCowHeader header; - Error *local_err = NULL; uint64_t ext_end; uint64_t l1_vm_state_index; bool update_header = false; @@ -1786,9 +1785,8 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ - bool header_updated = qcow2_load_dirty_bitmaps(bs, &local_err); - if (local_err != NULL) { - error_propagate(errp, local_err); + bool header_updated; + if (!qcow2_load_dirty_bitmaps(bs, &header_updated, errp)) { ret = -EINVAL; goto fail; }
It's recommended for bool functions with errp to return true on success and false on failure. Non-standard interfaces don't help to understand the code. The change is also needed to reduce error propagation. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- block/qcow2.h | 3 ++- block/qcow2-bitmap.c | 22 +++++++++------------- block/qcow2.c | 6 ++---- 3 files changed, 13 insertions(+), 18 deletions(-)