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2011-10-11block: Keep track of devices' I/O statusLuiz Capitulino1-0/+10
This commit adds support to the BlockDriverState type to keep track of devices' I/O status. There are three possible status: BDRV_IOS_OK (no error), BDRV_IOS_ENOSPC (no space error) and BDRV_IOS_FAILED (any other error). The distinction between no space and other errors is important because a management application may want to watch for no space in order to extend the space assigned to the VM and put it to run again. Qemu devices supporting the I/O status feature have to enable it explicitly by calling bdrv_iostatus_enable() _and_ have to be configured to stop the VM on errors (ie. werror=stop|enospc or rerror=stop). In case of multiple errors being triggered in sequence only the first one is stored. The I/O status is always reset to BDRV_IOS_OK when the 'cont' command is issued. Next commits will add support to some devices and extend the query-block/info block commands to return the I/O status information. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: New change_media_cb() parameter loadMarkus Armbruster1-1/+2
To let device models distinguish between eject and load. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: New bdrv_set_buffer_alignment()Markus Armbruster1-0/+1
Device models should be able to set it without an unclean include of block_int.h. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: Move BlockConf & friends from block_int.h to block.hMarkus Armbruster1-0/+38
It's convenience stuff for block device models, so block.h isn't the ideal home either, but better than block_int.h. Permits moving some #include "block_int.h" from device model .h into .c. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: Show whether the virtual tray is open in info blockMarkus Armbruster1-0/+6
Need to ask the device, so this requires new BlockDevOps member is_tray_open(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: Drop BlockDriverState member removableMarkus Armbruster1-1/+0
It's a confused mess (see previous commit). No users remain. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: Clean up remaining users of "removable"Markus Armbruster1-1/+2
BlockDriverState member removable is a confused mess. It is true when an ide-cd, scsi-cd or floppy qdev is attached, or when the BlockDriverState was created with -drive if={floppy,sd} or -drive if={ide,scsi,xen,none},media=cdrom ("created removable"), except when an ide-hd, scsi-hd, scsi-generic or virtio-blk qdev is attached. Three users remain: 1. eject_device(), via bdrv_is_removable() uses it to determine whether a block device can eject media. 2. bdrv_info() is monitor command "info block". QMP documentation says "true if the device is removable, false otherwise". From the monitor user's point of view, the only sensible interpretation of "is removable" is "can eject media with monitor commands eject and change". A block device can eject media unless a device is attached that doesn't support it. Switch the two users over to new bdrv_dev_has_removable_media() that returns exactly that. 3. bdrv_getlength() uses to suppress its length cache when media can change (see commit 46a4e4e6). Media change is either monitor command change (updates the length cache), monitor command eject (doesn't update the length cache, easily fixable), or physical media change (invalidates length cache, not so easily fixable). I'm refraining from improving anything here, because this series is long enough already. Instead, I simply switch it over to bdrv_dev_has_removable_media() as well. This changes the behavior of the length cache and of monitor commands eject and change in two cases: a. drive not created removable, no device attached The commit makes the drive removable, and defeats the length cache. Example: -drive if=none b. drive created removable, but the attached drive is non-removable, and doesn't call bdrv_set_removable(..., 0) (most devices don't) The commit makes the drive non-removable, and enables the length cache. Example: -drive if=xen,media=cdrom -M xenpv The other non-removable devices that don't call bdrv_set_removable() can't currently use a drive created removable, either because they aren't qdevified, or because they lack a drive property. Won't stay that way. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: Rename bdrv_set_locked() to bdrv_lock_medium()Markus Armbruster1-1/+1
While there, make the locked parameter bool. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: Drop medium lock tracking, ask device models insteadMarkus Armbruster1-1/+6
Requires new BlockDevOps member is_medium_locked(). Implement for IDE and SCSI CD-ROMs. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12block: Leave enforcing tray lock to device modelsMarkus Armbruster1-1/+1
The device model knows best when to accept the guest's eject command. No need to detour through the block layer. bdrv_eject() can't fail anymore. Make it void. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06block: Declare qemu_blockalign() in block.h, not block_int.hMarkus Armbruster1-0/+2
Device models should be able to use it without an unclean include of block_int.h. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06block: Split change_cb() into change_media_cb(), resize_cb()Markus Armbruster1-1/+11
Multiplexing callbacks complicates matters needlessly. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06block: Generalize change_cb() to BlockDevOpsMarkus Armbruster1-3/+6
So we can more easily add device model callbacks. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06block: Attach non-qdev devices as wellMarkus Armbruster1-3/+4
For now, this just protects against programming errors like having the same drive back multiple non-qdev devices, or untimely bdrv_delete(). Later commits will add other interesting uses. While there, rename BlockDriverState member peer to dev, bdrv_attach() to bdrv_attach_dev(), bdrv_detach() to bdrv_detach_dev(), and bdrv_get_attached() to bdrv_get_attached_dev(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-26block: latency accountingChristoph Hellwig1-0/+1
Account the total latency for read/write/flush requests. This allows management tools to average it based on a snapshot of the nr ops counters and allow checking for SLAs or provide statistics. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-25block: explicit I/O accountingChristoph Hellwig1-0/+17
Decouple the I/O accounting from bdrv_aio_readv/writev/flush and make the hardware models call directly into the accounting helpers. This means: - we do not count internal requests from image formats in addition to guest originating I/O - we do not double count I/O ops if the device model handles it chunk wise - we only account I/O once it actuall is done - can extent I/O accounting to synchronous or coroutine I/O easily - implement I/O latency tracking easily (see the next patch) I've conveted the existing device model callers to the new model, device models that are using synchronous I/O and weren't accounted before haven't been updated yet. Also scsi hasn't been converted to the end-to-end accounting as I want to defer that after the pending scsi layer overhaul. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23block: parse cache mode flags in a single placeStefan Hajnoczi1-0/+1
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>
2011-08-02block: Add bdrv_co_readv/writevKevin Wolf1-0/+5
Add new block driver callbacks bdrv_co_readv/writev, which work on a QEMUIOVector like bdrv_aio_*, but don't need a callback. The function may only be called inside a coroutine, so a block driver implementing this interface can yield instead of blocking during I/O. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-01block: Removed unused function bdrv_write_syncFrediano Ziglio1-2/+0
Signed-off-by: Frediano Ziglio <freddy77@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-07-19block: add bdrv_get_allocated_file_size() operationFam Zheng1-0/+1
qemu-img.c wants to count allocated file size of image. Previously it counts a single bs->file by 'stat' or Window API. As VMDK introduces multiple file support, the operation becomes format specific with platform specific meanwhile. The functions are moved to block/raw-{posix,win32}.c and qemu-img.c calls bdrv_get_allocated_file_size to count the bs. And also added VMDK code to count his own extents. Signed-off-by: Fam Zheng <famcool@gmail.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-15Replaced tabs with spaces in block.h and block_int.hDevin Nakamura1-3/+3
Signed-off-by: Devin Nakamura <devin122@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-05-19block: Remove type hint, it's guest matter, doesn't belong hereMarkus Armbruster1-5/+0
No users of bdrv_get_type_hint() left. bdrv_set_type_hint() can make the media removable by side effect. Make that explicit. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-04-07Do not delete BlockDriverState when deleting the driveRyan Harper1-0/+1
When removing a drive from the host-side via drive_del we currently have the following path: drive_del qemu_aio_flush() bdrv_close() // zaps bs->drv, which makes any subsequent I/O get // dropped. Works as designed drive_uninit() bdrv_delete() // frees the bs. Since the device is still connected to // bs, any subsequent I/O is a use-after-free. The value of bs->drv becomes unpredictable on free. As long as it remains null, I/O still gets dropped, however it could become non-null at any point after the free resulting SEGVs or other QEMU state corruption. To resolve this issue as simply as possible, we can chose to not actually delete the BlockDriverState pointer. Since bdrv_close() handles setting the drv pointer to NULL, we just need to remove the BlockDriverState from the QLIST that is used to enumerate the block devices. This is currently handled within bdrv_delete, so move this into its own function, bdrv_make_anon(). The result is that we can now invoke drive_del, this closes the file descriptors and sets BlockDriverState->drv to NULL which prevents futher IO to the device, and since we do not free BlockDriverState, we don't have to worry about the copy retained in the block devices. We also don't attempt to remove the qdev property since we are no longer deleting the BlockDriverState on drives with associated drives. This also allows for removing Drives with no devices associated either. Reported-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Ryan Harper <ryanh@us.ibm.com> Acked-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-02-20fdc: move floppy geometry guessing to block.cBlue Swirl1-0/+10
Other geometry guessing functions already reside in block.c. Remove some unused or debugging only fields. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-02-07Add flag to indicate external users to block deviceMarcelo Tosatti1-0/+2
Certain operations such as drive_del or resize cannot be performed while external users (eg. block migration) reference the block device. Add a flag to indicate that. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-01-31block: tell drivers about an image resizeChristoph Hellwig1-1/+2
Extend the change_cb callback with a reason argument, and use it to tell drivers about size changes. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17block: add discard supportChristoph Hellwig1-0/+1
Add a new bdrv_discard method to free blocks in a mapping image, and a new drive property to set the granularity for these discard. If no discard granularity support is set discard support is disabled. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17qemu-img.c: Re-factor img_create()Jes Sorensen1-0/+4
This patch re-factors img_create() moving the code doing the actual work into block.c where it can be shared with QEMU. This is needed to be able to create images from QEMU to be used for live snapshots. Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-11-04block: Allow bdrv_flush to return errorsKevin Wolf1-1/+1
This changes bdrv_flush to return 0 on success and -errno in case of failure. It's a requirement for implementing proper error handle in users of bdrv_flush. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-10-22Copy snapshots out of QCOW2 diskedison1-0/+2
In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage. The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img. Right now, it only supports to copy the full snapshot, delta snapshot is on the way. Changes from V1: all the comments from Kevin are addressed: Add read-only checking Fix coding style Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp Signed-off-by: Disheng Su <edison@cloud.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-09-08block: Fix BDRV_O_CACHE_MASKKevin Wolf1-1/+1
BDRV_O_CACHE_MASK should have been extended when cache=unsafe introduced a new flag BDRV_O_NO_FLUSH. There are currently no users that would change their behaviour because of this, but let's clean it up before things break. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-26Fix -snapshot deleting images on disk changeBlue Swirl1-0/+1
Block device change command did not copy BDRV_O_SNAPSHOT flag. Thus the new image did not have this flag and the file got deleted during opening. Fix by copying BDRV_O_SNAPSHOT flag. Signed-off-by: Blue Swirl <blauwirbel@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-06qemu-img check: Distinguish different kinds of errorsKevin Wolf1-1/+9
People think that their images are corrupted when in fact there are just some leaked clusters. Differentiating several error cases should make the messages more comprehensible. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-02block: Fix virtual media change for if=noneMarkus Armbruster1-0/+1
BlockDriverState member removable controls whether virtual media change (monitor commands change, eject) is allowed. It is set when the "type hint" is BDRV_TYPE_CDROM or BDRV_TYPE_FLOPPY. The type hint is only set by drive_init(). It sets BDRV_TYPE_FLOPPY for if=floppy. It sets BDRV_TYPE_CDROM for media=cdrom and if=ide, scsi, xen, or none. if=ide and if=scsi work, because the type hint makes it a CD-ROM. if=xen likewise, I think. For the same reason, if=none works when it's used by ide-drive or scsi-disk. For other guest devices, there are problems: * fdc: you can't change virtual media $ qemu [...] -drive if=none,id=foo,... -global isa-fdc.driveA=foo QEMU 0.12.50 monitor - type 'help' for more information (qemu) eject foo Device 'foo' is not removable unless you add media=cdrom, but that makes it readonly. * virtio: if you add media=cdrom, you can change virtual media. If you eject, the guest gets I/O errors. If you change, the guest sees the drive's contents suddenly change. * scsi-generic: if you add media=cdrom, you can change virtual media. I didn't test what that does to the guest or the physical device, but it can't be pretty. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-02savevm: Survive hot-unplug of snapshot deviceMarkus Armbruster1-0/+1
savevm.c keeps a pointer to the snapshot block device. If you manage to get that device deleted, the pointer dangles, and the next snapshot operation will crash & burn. Unplugging a guest device that uses it does the trick: $ MALLOC_PERTURB_=234 qemu-system-x86_64 [...] QEMU 0.12.50 monitor - type 'help' for more information (qemu) info snapshots No available block device supports snapshots (qemu) drive_add auto if=none,file=tmp.qcow2 OK (qemu) device_add usb-storage,id=foo,drive=none1 (qemu) info snapshots Snapshot devices: none1 Snapshot list (from none1): ID TAG VM SIZE DATE VM CLOCK (qemu) device_del foo (qemu) info snapshots Snapshot devices: Segmentation fault (core dumped) Move management of that pointer to block.c, and zap it when the device it points becomes unusable. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-02block: Catch attempt to attach multiple devices to a blockdevMarkus Armbruster1-0/+3
For instance, -device scsi-disk,drive=foo -device scsi-disk,drive=foo happily creates two SCSI disks connected to the same block device. It's all downhill from there. Device usb-storage deliberately attaches twice to the same blockdev, which fails with the fix in place. Detach before the second attach there. Also catch attempt to delete while a guest device model is attached. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-22block: Add bdrv_(p)write_syncKevin Wolf1-0/+4
Add new functions that write and flush the written data to disk immediately. This is what needs to be used for image format metadata to maintain integrity for cache=... modes that don't use O_DSYNC. (Actually, we only need barriers, and therefore the functions are defined as such, but flushes is what is implemented in this patch - we can try to change that later) Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-15block: New bdrv_next()Markus Armbruster1-0/+1
This is a more flexible alternative to bdrv_iterate(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-15block: Decouple block device "commit all" from DriveInfoMarkus Armbruster1-0/+1
do_commit() and mux_proc_byte() iterate over the list of drives defined with drive_init(). This misses host block devices defined by other means. Such means don't exist now, but will be introduced later in this series. Change them to use new bdrv_commit_all(), which iterates over all host block devices. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-15block: Move error actions from DriveInfo to BlockDriverStateMarkus Armbruster1-0/+8
That's where they belong semantically (block device host part), even though the actions are actually executed by guest device code. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-15savevm: Really verify if a drive supports snapshotsMiguel Di Ciurcio Filho1-0/+1
Both bdrv_can_snapshot() and bdrv_has_snapshot() does not work as advertized. First issue: Their names implies different porpouses, but they do the same thing and have exactly the same code. Maybe copied and pasted and forgotten? bdrv_has_snapshot() is called in various places for actually checking if there is snapshots or not. Second issue: the way bdrv_can_snapshot() verifies if a block driver supports or not snapshots does not catch all cases. E.g.: a raw image. So when do_savevm() is called, first thing it does is to set a global BlockDriverState to save the VM memory state calling get_bs_snapshots(). static BlockDriverState *get_bs_snapshots(void) { BlockDriverState *bs; DriveInfo *dinfo; if (bs_snapshots) return bs_snapshots; QTAILQ_FOREACH(dinfo, &drives, next) { bs = dinfo->bdrv; if (bdrv_can_snapshot(bs)) goto ok; } return NULL; ok: bs_snapshots = bs; return bs; } bdrv_can_snapshot() may return a BlockDriverState that does not support snapshots and do_savevm() goes on. Later on in do_savevm(), we find: QTAILQ_FOREACH(dinfo, &drives, next) { bs1 = dinfo->bdrv; if (bdrv_has_snapshot(bs1)) { /* Write VM state size only to the image that contains the state */ sn->vm_state_size = (bs == bs1 ? vm_state_size : 0); ret = bdrv_snapshot_create(bs1, sn); if (ret < 0) { monitor_printf(mon, "Error while creating snapshot on '%s'\n", bdrv_get_device_name(bs1)); } } } bdrv_has_snapshot(bs1) is not checking if the device does support or has snapshots as explained above. Only in bdrv_snapshot_create() the device is actually checked for snapshot support. So, in cases where the first device supports snapshots, and the second does not, the snapshot on the first will happen anyways. I believe this is not a good behavior. It should be an all or nothing process. This patch addresses these issues by making bdrv_can_snapshot() actually do what it must do and enforces better tests to avoid errors in the middle of do_savevm(). bdrv_has_snapshot() is removed and replaced by bdrv_can_snapshot() where appropriate. bdrv_can_snapshot() was moved from savevm.c to block.c. It makes more sense to me. The loadvm_state() function was updated too to enforce that when loading a VM at least all writable devices must support snapshots too. Signed-off-by: Miguel Di Ciurcio Filho <miguel.filho@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-04close all the block drivers before the qemu process exitsMORITA Kazutaka1-0/+1
This patch calls the close handler of the block driver before the qemu process exits. This is necessary because the sheepdog block driver releases the lock of VM images in the close handler. Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-28block.h: Make BDRV_SECTOR_SIZE 64 bit safeJes Sorensen1-1/+1
C defaults to int, so make definition of BDRV_SECTOR_SIZE 64 bit safe as it and BDRV_SECTOR_MASK may be used against 64 bit addresses. Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-28add support for protocol driver create_optionsMORITA Kazutaka1-0/+1
This patch enables protocol drivers to use their create options which are not supported by the format. For example, protcol drivers can use a backing_file option with raw format. Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-26Add cache=unsafe parameter to -driveAlexander Graf1-0/+1
Usually the guest can tell the host to flush data to disk. In some cases we don't want to flush though, but try to keep everything in cache. So let's add a new cache value to -drive that allows us to set the cache policy to most aggressive, disabling flushes. We call this mode "unsafe", as guest data is not guaranteed to survive host crashes anymore. This patch also adds a noop function for aio, so we can do nothing in AIO fashion. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-05-17block: Remove semicolon in BDRV_SECTOR_MASK macroStefan Hajnoczi1-1/+1
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03block: bdrv_has_zero_initKevin Wolf1-0/+1
This fixes the problem that qemu-img's use of no_zero_init only considered the no_zero_init flag of the format driver, but not of the underlying protocols. Between the raw/file split and this fix, converting to host devices is broken. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03block: separate raw images from the file protocolChristoph Hellwig1-0/+1
We're running into various problems because the "raw" file access, which is used internally by the various image formats is entangled with the "raw" image format, which maps the VM view 1:1 to a file system. This patch renames the raw file backends to the file protocol which is treated like other protocols (e.g. nbd and http) and adds a new "raw" image format which is just a wrapper around calls to the underlying protocol. The patch is surprisingly simple, besides changing the probing logical in block.c to only look for image formats when using bdrv_open and renaming of the old raw protocols to file there's almost nothing in there. For creating images, a new bdrv_create_file is introduced which guesses the protocol to use. This allows using qemu-img create -f raw (or just using the default) for both files and host devices. Converting the other format drivers to use this function to create their images is left for later patches. The only issues still open are in the handling of the host devices. Firstly in current qemu we can specifiy the host* format names on various command line acceping images, but the new code can't do that without adding some translation. Second the layering breaks the no_zero_init flag in the BlockDriver used by qemu-img. I'm not happy how this is done per-driver instead of per-state so I'll prepare a separate patch to clean this up. There's some more cleanup opportunity after this patch, e.g. using separate lists and registration functions for image formats vs protocols and maybe even host drivers, but this can be done at a later stage. Also there's a check for protocol in bdrv_open for the BDRV_O_SNAPSHOT case that I don't quite understand, but which I fear won't work as expected - possibly even before this patch. Note that this patch requires various recent block patches from Kevin and me, which should all be in his block queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23block.h: bdrv_create2 doesn't exist any moreKevin Wolf1-4/+0
The bdrv_create2 implementation has disappeared long ago. Remove its prototype from the header file, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23block: get rid of the BDRV_O_FILE flagChristoph Hellwig1-4/+0
BDRV_O_FILE is only used to communicate between bdrv_file_open and bdrv_open. It affects two things: first bdrv_open only searches for protocols using find_protocol instead of all image formats and host drivers. We can easily move that to the caller and pass the found driver to bdrv_open. Second it is used to not force a read-write open of a snapshot file. But we never use bdrv_file_open to open snapshots and this behaviour doesn't make sense to start with. qemu-io abused the BDRV_O_FILE for it's growable option, switch it to using bdrv_file_open to make sure we only open files as growable were we can actually support that. This patch requires Kevin's "[PATCH] Replace calls of old bdrv_open" to be applied first. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>