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2011-09-06savevm: Include writable devices with removable mediaMarkus Armbruster
savevm and loadvm silently ignore block devices with removable media, such as floppies and SD cards. Rolling back a VM to a previous checkpoint will *not* roll back writes to block devices with removable media. Moreover, bdrv_is_removable() is a confused mess, and wrong in at least one case: it considers "-drive if=xen,media=cdrom -M xenpv" removable. It'll be cleaned up later in this series. Read-only block devices are also ignored, but that's okay. Fix by ignoring only read-only block devices and empty block devices. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06block: Clean up bdrv_flush_all()Markus Armbruster
Change (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)) to just bdrv_is_inserted(). Rationale: The value of bdrv_is_removable(bs) matters only when bdrv_is_inserted(bs) is false. bdrv_is_inserted(bs) is true when bs is open (bs->drv != NULL) and not an empty host drive (CD-ROM or floppy). Therefore, bdrv_is_removable(bs) matters only when: 1. bs is not open old: may call bdrv_flush(bs), which does nothing new: won't call 2. bs is an empty host drive old: may call bdrv_flush(bs), which calls driver method raw_flush(), which calls fdatasync() or equivalent, which can't do anything useful while the drive is empty new: won't call Result is bs->drv && !bdrv_is_read_only(bs) && bdrv_is_inserted(bs). bdrv_is_inserted(bs) implies bs->drv. Drop the redundant test. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06block: Leave tracking media change to device modelsMarkus Armbruster
hw/fdc.c is the only one that cares. 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 Armbruster
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 Armbruster
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 Armbruster
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>
2011-09-03Use new macro QEMU_PACKED for packed structuresStefan Weil
Most changes were made using these commands: git grep -la '__attribute__((packed))'|xargs perl -pi -e 's/__attribute__\(\(packed\)\)/QEMU_PACKED/' git grep -la '__attribute__ ((packed))'|xargs perl -pi -e 's/__attribute__ \(\(packed\)\)/QEMU_PACKED/' git grep -la '__attribute__((__packed__))'|xargs perl -pi -e 's/__attribute__\(\(__packed__\)\)/QEMU_PACKED/' git grep -la '__attribute__ ((__packed__))'|xargs perl -pi -e 's/__attribute__ \(\(__packed__\)\)/QEMU_PACKED/' git grep -la '__attribute((packed))'|xargs perl -pi -e 's/__attribute\(\(packed\)\)/QEMU_PACKED/' Whitespace in linux-user/syscall_defs.h was fixed manually to avoid warnings from scripts/checkpatch.pl. Manual changes were also applied to hw/pc.c. I did not fix indentation with tabs in block/vvfat.c. The patch will show 4 errors with scripts/checkpatch.pl. Signed-off-by: Stefan Weil <weil@mail.berlios.de> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-08-26block: latency accountingChristoph Hellwig
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 Hellwig
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: include flush requests in info blockstatsChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23block: add cache=directsync parameter to -driveStefan Hajnoczi
This patch adds -drive cache=directsync for O_DIRECT | O_SYNC host file I/O with no disk write cache presented to the guest. This mode is useful when guests may not be sending flushes when appropriate and therefore leave data at risk in case of power failure. When cache=directsync is used, write operations are only completed to the guest when data is safely on disk. This new mode is like cache=writethrough but it bypasses the host page cache. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-23block: parse cache mode flags in a single placeStefan Hajnoczi
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>
2011-08-22fix code formatRobert Wang
Fix code format to make checkpatch.pl happy. Signed-off-by: Robert Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20Use glib memory allocation and free functionsAnthony Liguori
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-04block: Use bdrv_co_* instead of synchronous versions in coroutinesKevin Wolf
If we're already in a coroutine, there is no reason to use the synchronous version of block layer functions when a coroutine one exists. This makes bdrv_read/write/flush use bdrv_co_* when used inside a coroutine. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-02async: Remove AsyncContextKevin Wolf
The purpose of AsyncContexts was to protect qcow and qcow2 against reentrancy during an emulated bdrv_read/write (which includes a qemu_aio_wait() call and can run AIO callbacks of different requests if it weren't for AsyncContexts). Now both qcow and qcow2 are protected by CoMutexes and AsyncContexts can be removed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-02block: Add bdrv_co_readv/writev emulationKevin Wolf
In order to be able to call bdrv_co_readv/writev for drivers that don't implement the functions natively, add an emulation that uses the AIO functions to implement them. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-02block: Emulate AIO functions with bdrv_co_readv/writevKevin Wolf
Use the bdrv_co_readv/writev callbacks to implement bdrv_aio_readv/writev and bdrv_read/write if a driver provides the coroutine version instead of the synchronous or AIO version. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-02block: Add bdrv_co_readv/writevKevin Wolf
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 Ziglio
Signed-off-by: Frediano Ziglio <freddy77@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-01block: Don't let locked flag prevent medium loadMarkus Armbruster
Commit aea2a33c made bdrv_eject() obey the locked flag. Correct for medium eject (eject_flag set), incorrect for medium load (eject_flag clear). See MMC-5 Table 341 "Actions for Lock/Unlock/Eject". Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-01block: Make BlockDriver method bdrv_eject() return voidMarkus Armbruster
Callees always return 0, except for FreeBSD's cdrom_eject(), which returns -ENOTSUP when the device is in a terminally wedged state. The only caller is bdrv_eject(), and it maps -ENOTSUP to 0 since commit 4be9762a. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-01block: Reset device model callbacks on detachMarkus Armbruster
BlockDriverState members change_cb and change_opaque are initially null. The device model may set them, with bdrv_set_change_cb(). If the device model gets detached (hot unplug), they're left dangling. Only safe because device hot unplug automatically destroys the BlockDriverState. But that's a questionable feature, best not to rely on it. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-07-19block: add bdrv_get_allocated_file_size() operationFam Zheng
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>
2011-06-08bdrv_img_create: Fix segfaultKevin Wolf
Block drivers that don't support creating images don't have a size option. Fail gracefully instead of segfaulting when trying to access the option's value. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08block: clarify the meaning of BDRV_O_NOCACHEChristoph Hellwig
Change BDRV_O_NOCACHE to only imply bypassing the host OS file cache, but no writeback semantics. All existing callers are changed to also specify BDRV_O_CACHE_WB to give them writeback semantics. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-05-19block: Remove type hint, it's guest matter, doesn't belong hereMarkus Armbruster
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>
2011-05-19block QMP: Deprecate query-block's "type", drop info block's "type="Markus Armbruster
query-block's specification documents response member "type" with values "hd", "cdrom", "floppy", "unknown". Its value is unreliable: a block device used as floppy has type "floppy" if created with if=floppy, but type "hd" if created with if=none. That's because with if=none, the type is at best a declaration of intent: the drive can be connected to any guest device. Its type is really the guest device's business. Reporting it here is wrong. No known user of QMP uses "type". It's unlikely that any unknown users exist, because its value is useless unless you know how the block device was created. But then you also know the true value. Fixing the broken value risks breaking (hypothetical!) clients that somehow rely on the current behavior. Not fixing the value risks breaking (hypothetical!) clients that rely on the value to be accurate. Can't entirely avoid hypothetical lossage. Change the value to be always "unknown". This makes "info block" always report "type=unknown". Pointless. Change it to not report the type. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-05-08Fix typos in comments and code (occured -> occurred and related)Stefan Weil
The code changed here is an unused data type name (evt_flush_occurred). Signed-off-by: Stefan Weil <weil@mail.berlios.de> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-05-06Fix typo in code and commentsStefan Weil
Replace writeable -> writable Signed-off-by: Stefan Weil <weil@mail.berlios.de> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-04-07block: Do not cache device size for removable mediaStefan Hajnoczi
The block layer caches the device size to avoid doing lseek(fd, 0, SEEK_END) every time this value is needed. For removable media the device size becomes stale if a new medium is inserted. This patch simply prevents device size caching for removable media. A smarter solution is to update the cached device size when a new medium is inserted. Given that there are currently bugs with CD-ROM media change I do not want to implement that approach until we've gotten things correct first. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-04-07trace: Trace bdrv_set_locked()Stefan Hajnoczi
It can be handy to know when the guest locks/unlocks the CD-ROM tray. This trace event makes that possible. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-04-07Do not delete BlockDriverState when deleting the driveRyan Harper
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>
2011-03-15Don't allow multiwrites against a block device without underlying mediumRyan Harper
If the block device has been closed, we no longer have a medium to submit IO against, check for this before submitting io. This prevents a segfault further in the code where we dereference elements of the block driver. Signed-off-by: Ryan Harper <ryanh@us.ibm.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-03-07trace: Trace bdrv_aio_flush()Stefan Hajnoczi
Add a trace event for bdrv_aio_flush() to complement the existing bdrv_aio_readv() and bdrv_aio_writev() events. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-02-20fdc: move floppy geometry guessing to block.cBlue Swirl
Other geometry guessing functions already reside in block.c. Remove some unused or debugging only fields. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-02-07block: enable in_use flagMarcelo Tosatti
Set block device in use during block migration, disallow drive_del and bdrv_truncate for in use devices. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-02-07Add flag to indicate external users to block deviceMarcelo Tosatti
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 Hellwig
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>
2011-01-24block: Use backing format driver during image creationStefan Hajnoczi
The backing format should be honored during image creation. For some reason we currently use the image format to open the backing file. This fails when the backing file has a different format than the image being created. Keep the image and backing format drivers completely separate. Also print the backing filename if there is an error opening the backing file instead of the image filename. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Acked-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-01-06block: delete a write-only variableBlue Swirl
Avoid a warning with GCC 4.6.0: /src/qemu/block.c: In function 'bdrv_img_create': /src/qemu/block.c:2862:25: error: variable 'fmt' set but not used [-Werror=unused-but-set-variable] CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-12-17block: add discard supportChristoph Hellwig
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>
2010-12-17bdrv_img_create() use proper errno return valuesJes Sorensen
Kevin suggested to have bdrv_img_create() return proper -errno values on error. Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17Prevent creating an image with the same filename as backing fileJes Sorensen
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17qemu-img.c: Re-factor img_create()Jes Sorensen
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>
2010-12-17block: Fix the use of protocols in backing filesStefan Hajnoczi
Backing filenames may contain a protocol. The code currently doesn't consider this case and produces filenames that embed "<protocol>:". Don't combine filenames if the backing filename contains a protocol. Based on an earlier patch by Anthony Liguori <aliguori@us.ibm.com>. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17block: Introduce path_has_protocol() functionStefan Hajnoczi
The bdrv_find_protocol() function returns NULL if an unknown protocol name is given. It returns the "file" protocol when the filename contains no protocol at all. This makes it difficult to distinguish between paths which contain a protocol and those which do not. Factor out a helper function that tests whether or not a filename has a protocol. The next patch makes use of this function. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-14block: Make bdrv_create_file() ':' handling consistentStefan Hajnoczi
Filenames may start with "<protocol>:" to explicitly use a protocol like nbd. Filenames with unknown protocols are rejected in most of QEMU except for bdrv_create_file(). Even if a file with an invalid filename can be created, QEMU cannot use it since all the other relevant functions reject such paths. Make bdrv_create_file() consistent. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-11-21block: set sector dirty on AIO write completionMarcelo Tosatti
Sectors are marked dirty in the bitmap on AIO submission. This is wrong since data has not reached storage. Set a given sector as dirty in the dirty bitmap on AIO completion, so that reading a sector marked as dirty is guaranteed to return uptodate data. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-11-21block: fix shift in dirty bitmap calculationMarcelo Tosatti
Otherwise upper 32 bits of bitmap entries are not correctly calculated. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>