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454ae734f1
Support backend option "direct-io-safe". This is documented as follows in the Xen backend specification: * direct-io-safe * Values: 0/1 (boolean) * Default Value: 0 * * The underlying storage is not affected by the direct IO memory * lifetime bug. See: * http://lists.xen.org/archives/html/xen-devel/2012-12/msg01154.html * * Therefore this option gives the backend permission to use * O_DIRECT, notwithstanding that bug. * * That is, if this option is enabled, use of O_DIRECT is safe, * in circumstances where we would normally have avoided it as a * workaround for that bug. This option is not relevant for all * backends, and even not necessarily supported for those for * which it is relevant. A backend which knows that it is not * affected by the bug can ignore this option. * * This option doesn't require a backend to use O_DIRECT, so it * should not be used to try to control the caching behaviour. Also, BDRV_O_NATIVE_AIO is ignored if BDRV_O_NOCACHE, so clarify the default flags passed to the qemu block layer. The original proposal for a "cache" backend option has been dropped because it was believed too wide, especially considering that at the moment the backend doesn't have a way to tell the toolstack that it is capable of supporting it. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com> |
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| .. | ||
| dataplane | ||
| block.c | ||
| cdrom.c | ||
| ecc.c | ||
| fdc.c | ||
| hd-geometry.c | ||
| m25p80.c | ||
| Makefile.objs | ||
| nand.c | ||
| nvme.c | ||
| nvme.h | ||
| onenand.c | ||
| pc_sysfw.c | ||
| pflash_cfi01.c | ||
| pflash_cfi02.c | ||
| tc58128.c | ||
| virtio-blk.c | ||
| xen_blkif.h | ||
| xen_disk.c | ||