block: parse cache mode flags in a single place

This patch introduces bdrv_parse_cache_flags() which sets open flags
given a cache mode.  Previously this was duplicated in blockdev.c and
qemu-img.c.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2011-08-04 12:26:51 +01:00 committed by Kevin Wolf
parent 12888904fe
commit c3993cdca3
4 changed files with 32 additions and 36 deletions

25
block.c
View file

@ -437,6 +437,31 @@ static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
return 0;
}
/**
* Set open flags for a given cache mode
*
* Return 0 on success, -1 if the cache mode was invalid.
*/
int bdrv_parse_cache_flags(const char *mode, int *flags)
{
*flags &= ~BDRV_O_CACHE_MASK;
if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
*flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
} else if (!strcmp(mode, "writeback")) {
*flags |= BDRV_O_CACHE_WB;
} else if (!strcmp(mode, "unsafe")) {
*flags |= BDRV_O_CACHE_WB;
*flags |= BDRV_O_NO_FLUSH;
} else if (!strcmp(mode, "writethrough")) {
/* this is the default */
} else {
return -1;
}
return 0;
}
/*
* Common part for opening disk images and files
*/