diff options
Diffstat (limited to 'block/qcow2.c')
| -rw-r--r-- | block/qcow2.c | 50 |
1 files changed, 47 insertions, 3 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 870148ddf8..7fe156712a 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -214,6 +214,27 @@ static void report_unsupported_feature(BlockDriverState *bs, } } +/* + * Clears the dirty bit and flushes before if necessary. Only call this + * function when there are no pending requests, it does not guard against + * concurrent requests dirtying the image. + */ +static int qcow2_mark_clean(BlockDriverState *bs) +{ + BDRVQcowState *s = bs->opaque; + + if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { + int ret = bdrv_flush(bs); + if (ret < 0) { + return ret; + } + + s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; + return qcow2_update_header(bs); + } + return 0; +} + static int qcow2_open(BlockDriverState *bs, int flags) { BDRVQcowState *s = bs->opaque; @@ -287,12 +308,13 @@ static int qcow2_open(BlockDriverState *bs, int flags) s->compatible_features = header.compatible_features; s->autoclear_features = header.autoclear_features; - if (s->incompatible_features != 0) { + if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { void *feature_table = NULL; qcow2_read_extensions(bs, header.header_length, ext_end, &feature_table); report_unsupported_feature(bs, feature_table, - s->incompatible_features); + s->incompatible_features & + ~QCOW2_INCOMPAT_MASK); ret = -ENOTSUP; goto fail; } @@ -412,6 +434,22 @@ static int qcow2_open(BlockDriverState *bs, int flags) /* Initialise locks */ qemu_co_mutex_init(&s->lock); + /* Repair image if dirty */ + if ((s->incompatible_features & QCOW2_INCOMPAT_DIRTY) && + !bs->read_only) { + BdrvCheckResult result = {0}; + + ret = qcow2_check_refcounts(bs, &result, BDRV_FIX_ERRORS); + if (ret < 0) { + goto fail; + } + + ret = qcow2_mark_clean(bs); + if (ret < 0) { + goto fail; + } + } + #ifdef DEBUG_ALLOC { BdrvCheckResult result = {0}; @@ -785,6 +823,8 @@ static void qcow2_close(BlockDriverState *bs) qcow2_cache_flush(bs, s->l2_table_cache); qcow2_cache_flush(bs, s->refcount_block_cache); + qcow2_mark_clean(bs); + qcow2_cache_destroy(bs, s->l2_table_cache); qcow2_cache_destroy(bs, s->refcount_block_cache); @@ -949,7 +989,11 @@ int qcow2_update_header(BlockDriverState *bs) /* Feature table */ Qcow2Feature features[] = { - /* no feature defined yet */ + { + .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, + .bit = QCOW2_INCOMPAT_DIRTY_BITNR, + .name = "dirty bit", + }, }; ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, |