Assign directly to the bdrv_flags variable instead of using magic numbers before translating to the BDRV_O_* options.
Signed-off-by: Christoph Hellwig <h...@lst.de> Index: qemu/vl.c =================================================================== --- qemu.orig/vl.c 2010-04-05 11:05:39.042010326 +0200 +++ qemu/vl.c 2010-04-05 11:12:18.235256380 +0200 @@ -851,10 +851,8 @@ DriveInfo *drive_init(QemuOpts *opts, vo QEMUMachine *machine = opaque; int max_devs; int index; - int cache; - int aio = 0; int ro = 0; - int bdrv_flags; + int bdrv_flags = 0; int on_read_error, on_write_error; const char *devaddr; DriveInfo *dinfo; @@ -863,7 +861,6 @@ DriveInfo *drive_init(QemuOpts *opts, vo *fatal_error = 1; translation = BIOS_ATA_TRANSLATION_AUTO; - cache = 1; if (machine && machine->use_scsi) { type = IF_SCSI; @@ -978,11 +975,11 @@ DriveInfo *drive_init(QemuOpts *opts, vo if ((buf = qemu_opt_get(opts, "cache")) != NULL) { if (!strcmp(buf, "off") || !strcmp(buf, "none")) - cache = 0; - else if (!strcmp(buf, "writethrough")) - cache = 1; + bdrv_flags |= BDRV_O_NOCACHE; else if (!strcmp(buf, "writeback")) - cache = 2; + bdrv_flags |= BDRV_O_CACHE_WB; + else if (!strcmp(buf, "writethrough")) + /* this is the default */; else { fprintf(stderr, "qemu: invalid cache option\n"); return NULL; @@ -991,10 +988,10 @@ DriveInfo *drive_init(QemuOpts *opts, vo #ifdef CONFIG_LINUX_AIO if ((buf = qemu_opt_get(opts, "aio")) != NULL) { + if (!strcmp(buf, "native")) + bdrv_flags |= BDRV_O_NATIVE_AIO; if (!strcmp(buf, "threads")) - aio = 0; - else if (!strcmp(buf, "native")) - aio = 1; + /* this is the default */; else { fprintf(stderr, "qemu: invalid aio option\n"); return NULL; @@ -1169,20 +1166,10 @@ DriveInfo *drive_init(QemuOpts *opts, vo *fatal_error = 0; return NULL; } - bdrv_flags = 0; if (snapshot) { - bdrv_flags |= BDRV_O_SNAPSHOT; - cache = 2; /* always use write-back with snapshot */ - } - if (cache == 0) /* no caching */ - bdrv_flags |= BDRV_O_NOCACHE; - else if (cache == 2) /* write-back */ - bdrv_flags |= BDRV_O_CACHE_WB; - - if (aio == 1) { - bdrv_flags |= BDRV_O_NATIVE_AIO; - } else { - bdrv_flags &= ~BDRV_O_NATIVE_AIO; + /* always use write-back with snapshot */ + bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB); + bdrv_flags &= ~BDRV_O_NOCACHE; } if (ro == 1) {