mirror of https://gitee.com/openkylin/qemu.git
1c14eaabdb
The new block driver simply utilizes snapshot-access API of underlying block node. In further patches we want to use it like this: [guest] [NBD export] | | | root | root v file v [copy-before-write]<------[snapshot-access] | | | file | target v v [active-disk] [temp.img] This way, NBD client will be able to read snapshotted state of active disk, when active disk is continued to be written by guest. This is known as "fleecing", and currently uses another scheme based on qcow2 temporary image which backing file is active-disk. New scheme comes with benefits - see next commit. The other possible application is exporting internal snapshots of qcow2, like this: [guest] [NBD export] | | | root | root v file v [qcow2]<---------[snapshot-access] For this, we'll need to implement snapshot-access API handlers in qcow2 driver, and improve snapshot-access block driver (and API) to make it possible to select snapshot by name. Another thing to improve is size of snapshot. Now for simplicity we just use size of bs->file, which is OK for backup, but for qcow2 snapshots export we'll need to imporve snapshot-access API to get size of snapshot. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20220303194349.2304213-12-vsementsov@virtuozzo.com> [hreitz: Rebased on block GS/IO split] Signed-off-by: Hanna Reitz <hreitz@redhat.com> |
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| .. | ||
| authz | ||
| block | ||
| chardev | ||
| crypto | ||
| disas | ||
| exec | ||
| fpu | ||
| hw | ||
| io | ||
| libdecnumber | ||
| migration | ||
| monitor | ||
| net | ||
| qapi | ||
| qemu | ||
| qom | ||
| scsi | ||
| semihosting | ||
| standard-headers | ||
| sysemu | ||
| tcg | ||
| ui | ||
| user | ||
| elf.h | ||
| glib-compat.h | ||
| qemu-common.h | ||
| qemu-io.h | ||