diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 89 |
1 files changed, 65 insertions, 24 deletions
diff --git a/block.c b/block.c index afaff93423..493ecf3137 100644 --- a/block.c +++ b/block.c @@ -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 */ } }, }; @@ -961,6 +985,8 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file, goto fail_opts; } + update_flags_from_options(&bs->open_flags, opts); + driver_name = qemu_opt_get(opts, "driver"); drv = bdrv_find_format(driver_name); assert(drv != NULL); @@ -1022,9 +1048,6 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file, bs->drv = drv; bs->opaque = g_malloc0(drv->instance_size); - /* Apply cache mode options */ - update_flags_from_options(&bs->open_flags, opts); - /* Open the image, either directly or using a protocol */ open_flags = bdrv_open_flags(bs, bs->open_flags); if (drv->bdrv_file_open) { @@ -1675,6 +1698,25 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, goto fail; } + /* 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); + } + bs->open_flags = flags; bs->options = options; options = qdict_clone_shallow(options); @@ -1699,18 +1741,6 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, /* Open image file without format layer */ if ((flags & BDRV_O_PROTOCOL) == 0) { - if (flags & BDRV_O_RDWR) { - flags |= BDRV_O_ALLOW_RDWR; - } - if (flags & BDRV_O_SNAPSHOT) { - snapshot_options = qdict_new(); - bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options, - flags, options); - bdrv_backing_options(&flags, options, flags, options); - } - - bs->open_flags = flags; - file = bdrv_open_child(filename, options, "file", bs, &child_file, true, &local_err); if (local_err) { @@ -1895,6 +1925,13 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, options = qdict_new(); } + /* Check if this BlockDriverState is already in the queue */ + QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { + if (bs == bs_entry->state.bs) { + break; + } + } + /* * Precedence of options: * 1. Explicitly passed in options (highest) @@ -1915,7 +1952,11 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, } /* Old explicitly set values (don't overwrite by inherited value) */ - old_options = qdict_clone_shallow(bs->explicit_options); + if (bs_entry) { + old_options = qdict_clone_shallow(bs_entry->state.explicit_options); + } else { + old_options = qdict_clone_shallow(bs->explicit_options); + } bdrv_join_options(bs, options, old_options); QDECREF(old_options); @@ -1954,8 +1995,13 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, child->role, options, flags); } - bs_entry = g_new0(BlockReopenQueueEntry, 1); - QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); + if (!bs_entry) { + bs_entry = g_new0(BlockReopenQueueEntry, 1); + QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); + } else { + QDECREF(bs_entry->state.options); + QDECREF(bs_entry->state.explicit_options); + } bs_entry->state.bs = bs; bs_entry->state.options = options; @@ -3013,11 +3059,6 @@ bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) return false; } -int bdrv_is_snapshot(BlockDriverState *bs) -{ - return !!(bs->open_flags & BDRV_O_SNAPSHOT); -} - /* backing_file can either be relative, or absolute, or a protocol. If it is * relative, it must be relative to the chain. So, passing in bs->filename * from a BDS as backing_file should not be done, as that may be relative to |