From 8e2160e2c75522554647e197e8b61622d6cf076f Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 29 Apr 2015 17:29:39 +0200 Subject: block: Add infrastructure for option inheritance Options are not actually inherited from the parent node yet, but this commit lays the grounds for doing so. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block.c | 52 ++++++++++++++++++++++++++++------------------- include/block/block_int.h | 3 ++- 2 files changed, 33 insertions(+), 22 deletions(-) diff --git a/block.c b/block.c index 5fd6c444ac..6c940a7a25 100644 --- a/block.c +++ b/block.c @@ -695,11 +695,14 @@ static int bdrv_temp_snapshot_flags(int flags) } /* - * Returns the flags that bs->file should get if a protocol driver is expected, - * based on the given flags for the parent BDS + * Returns the options and flags that bs->file should get if a protocol driver + * is expected, based on the given options and flags for the parent BDS */ -static int bdrv_inherited_flags(int flags) +static void bdrv_inherited_options(int *child_flags, QDict *child_options, + int parent_flags, QDict *parent_options) { + int flags = parent_flags; + /* Enable protocol handling, disable format probing for bs->file */ flags |= BDRV_O_PROTOCOL; @@ -710,45 +713,51 @@ static int bdrv_inherited_flags(int flags) /* Clear flags that only apply to the top layer */ flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ); - return flags; + *child_flags = flags; } const BdrvChildRole child_file = { - .inherit_flags = bdrv_inherited_flags, + .inherit_options = bdrv_inherited_options, }; /* - * Returns the flags that bs->file should get if the use of formats (and not - * only protocols) is permitted for it, based on the given flags for the parent - * BDS + * Returns the options and flags that bs->file should get if the use of formats + * (and not only protocols) is permitted for it, based on the given options and + * flags for the parent BDS */ -static int bdrv_inherited_fmt_flags(int parent_flags) +static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options, + int parent_flags, QDict *parent_options) { - int flags = child_file.inherit_flags(parent_flags); - return flags & ~BDRV_O_PROTOCOL; + child_file.inherit_options(child_flags, child_options, + parent_flags, parent_options); + + *child_flags &= ~BDRV_O_PROTOCOL; } const BdrvChildRole child_format = { - .inherit_flags = bdrv_inherited_fmt_flags, + .inherit_options = bdrv_inherited_fmt_options, }; /* - * Returns the flags that bs->backing should get, based on the given flags - * for the parent BDS + * Returns the options and flags that bs->backing should get, based on the + * given options and flags for the parent BDS */ -static int bdrv_backing_flags(int flags) +static void bdrv_backing_options(int *child_flags, QDict *child_options, + int parent_flags, QDict *parent_options) { + int flags = parent_flags; + /* backing files always opened read-only */ flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ); /* snapshot=on is handled on the top layer */ flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); - return flags; + *child_flags = flags; } static const BdrvChildRole child_backing = { - .inherit_flags = bdrv_backing_flags, + .inherit_options = bdrv_backing_options, }; static int bdrv_open_flags(BlockDriverState *bs, int flags) @@ -1480,7 +1489,8 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, if (child_role) { bs->inherits_from = parent; - flags = child_role->inherit_flags(parent->open_flags); + child_role->inherit_options(&flags, options, + parent->open_flags, parent->options); } ret = bdrv_fill_options(&options, &filename, &flags, &local_err); @@ -1518,7 +1528,7 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, } if (flags & BDRV_O_SNAPSHOT) { snapshot_flags = bdrv_temp_snapshot_flags(flags); - flags = bdrv_backing_flags(flags); + bdrv_backing_options(&flags, options, flags, options); } bs->open_flags = flags; @@ -1721,14 +1731,14 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, * 1. Explicitly passed in options (highest) * 2. TODO Set in flags (only for top level) * 3. TODO Retained from explicitly set options of bs - * 4. TODO Inherited from parent node + * 4. Inherited from parent node * 5. Retained from effective options of bs */ /* Inherit from parent node */ if (parent_options) { assert(!flags); - flags = role->inherit_flags(parent_flags); + role->inherit_options(&flags, options, parent_flags, parent_options); } /* Old values are used for options that aren't set yet */ diff --git a/include/block/block_int.h b/include/block/block_int.h index 98336f60dd..abb6224439 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -343,7 +343,8 @@ typedef struct BdrvAioNotifier { } BdrvAioNotifier; struct BdrvChildRole { - int (*inherit_flags)(int parent_flags); + void (*inherit_options)(int *child_flags, QDict *child_options, + int parent_flags, QDict *parent_options); }; extern const BdrvChildRole child_file; -- cgit v1.2.3