diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 38 |
1 files changed, 35 insertions, 3 deletions
@@ -733,6 +733,9 @@ static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options, qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off"); qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on"); + /* Copy the read-only option from the parent */ + qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); + /* aio=native doesn't work for cache.direct=off, so disable it for the * temporary snapshot */ *child_flags &= ~BDRV_O_NATIVE_AIO; @@ -755,6 +758,9 @@ static void bdrv_inherited_options(int *child_flags, QDict *child_options, qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); + /* Inherit the read-only option from the parent if it's not set */ + qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); + /* Our block drivers take care to send flushes and respect unmap policy, * so we can default to enable both on lower layers regardless of the * corresponding parent options. */ @@ -808,7 +814,8 @@ static void bdrv_backing_options(int *child_flags, QDict *child_options, qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); /* backing files always opened read-only */ - flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ); + qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on"); + flags &= ~BDRV_O_COPY_ON_READ; /* snapshot=on is handled on the top layer */ flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); @@ -855,6 +862,14 @@ static void update_flags_from_options(int *flags, QemuOpts *opts) if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) { *flags |= BDRV_O_NOCACHE; } + + *flags &= ~BDRV_O_RDWR; + + assert(qemu_opt_find(opts, BDRV_OPT_READ_ONLY)); + if (!qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false)) { + *flags |= BDRV_O_RDWR; + } + } static void update_options_from_flags(QDict *options, int flags) @@ -867,6 +882,10 @@ static void update_options_from_flags(QDict *options, int flags) qdict_put(options, BDRV_OPT_CACHE_NO_FLUSH, qbool_from_bool(flags & BDRV_O_NO_FLUSH)); } + if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) { + qdict_put(options, BDRV_OPT_READ_ONLY, + qbool_from_bool(!(flags & BDRV_O_RDWR))); + } } static void bdrv_assign_node_name(BlockDriverState *bs, @@ -930,6 +949,11 @@ static QemuOptsList bdrv_runtime_opts = { .type = QEMU_OPT_BOOL, .help = "Ignore flush requests", }, + { + .name = BDRV_OPT_READ_ONLY, + .type = QEMU_OPT_BOOL, + .help = "Node is opened in read-only mode", + }, { /* end of list */ } }, }; @@ -1674,14 +1698,22 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, goto fail; } - if (flags & BDRV_O_RDWR) { - flags |= BDRV_O_ALLOW_RDWR; + /* Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags. + * FIXME: we're parsing the QDict to avoid having to create a + * QemuOpts just for this, but neither option is optimal. */ + if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") && + !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) { + flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR); + } else { + flags &= ~BDRV_O_RDWR; } if (flags & BDRV_O_SNAPSHOT) { snapshot_options = qdict_new(); bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options, flags, options); + /* Let bdrv_backing_options() override "read-only" */ + qdict_del(options, BDRV_OPT_READ_ONLY); bdrv_backing_options(&flags, options, flags, options); } |