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2014-11-03block: Add status callback to bdrv_amend_options()Max Reitz
Depending on the changed options and the image format, bdrv_amend_options() may take a significant amount of time. In these cases, a way to be informed about the operation's status is desirable. Since the operation is rather complex and may fundamentally change the image, implementing it as AIO or a coroutine does not seem feasible. On the other hand, implementing it as a block job would be significantly more difficult than a simple callback and would not add benefits other than progress report to the amending operation, because it should not actually be run as a block job at all. A callback may not be very pretty, but it's very easy to implement and perfectly fits its purpose here. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1414404776-4919-2-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03qemu-img: Implement commit like QMPMax Reitz
qemu-img should use QMP commands whenever possible in order to ensure feature completeness of both online and offline image operations. As qemu-img itself has no access to QMP (since this would basically require just everything being linked into qemu-img), imitate QMP's implementation of block-commit by using commit_active_start() and then waiting for the block job to finish. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1414159063-25977-9-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03block/mirror: Improve progress reportMax Reitz
Instead of taking the total length of the block device as the block job's length, use the number of dirty sectors. The progress is now the number of sectors mirrored to the target block device. Note that this may result in the job's length increasing during operation, which is however in fact desirable. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1414159063-25977-8-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03qcow2: Optimize bdrv_make_empty()Max Reitz
bdrv_make_empty() is currently only called if the current image represents an external snapshot that has been committed to its base image; it is therefore unlikely to have internal snapshots. In this case, bdrv_make_empty() can be greatly sped up by emptying the L1 and refcount table (while having the dirty flag set, which only works for compat=1.1) and creating a trivial refcount structure. If there are snapshots or for compat=0.10, fall back to the simple implementation (discard all clusters). [Applied s/clusters/cluster/ typo fix suggested by Eric Blake --Stefan] Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1414159063-25977-4-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03qcow2: Implement bdrv_make_empty()Max Reitz
Implement this function by making all clusters in the image file fall through to the backing file (by using the recently extended discard). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1414159063-25977-3-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03qcow2: Allow "full" discardMax Reitz
Normally, discarded sectors should read back as zero. However, there are cases in which a sector (or rather cluster) should be discarded as if they were never written in the first place, that is, reading them should fall through to the backing file again. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1414159063-25977-2-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03raw-posix: raw_co_get_block_status() return valueMax Reitz
Instead of generating the full return value thrice in try_fiemap(), try_seek_hole() and as a fall-back in raw_co_get_block_status() itself, generate the value only in raw_co_get_block_status(). While at it, also remove the pnum parameter from try_fiemap() and try_seek_hole(). Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1414148280-17949-3-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03raw-posix: Fix raw_co_get_block_status() after EOFMax Reitz
As its comment states, raw_co_get_block_status() should unconditionally return 0 and set *pnum to 0 for after EOF. An assertion after lseek(..., SEEK_HOLE) tried to catch this case by asserting that errno != -ENXIO (which would indicate a position after the EOF); but it should be errno != ENXIO instead. Regardless of that, there should be no such assertion at all. If bdrv_getlength() returned an outdated value and the image has been resized outside of qemu, lseek() will return with errno == ENXIO. Just return that value as an error then. Setting *pnum to 0 and returning 0 should not be done here, as in that case we should update the device length as well. So, from qemu's perspective, the file has not been resized; it's just that there was an error querying sectors beyond a certain point (the actual file size). Additionally, nb_sectors should be clamped against the image end. This was probably not an issue if FIEMAP or SEEK_HOLE/SEEK_DATA worked, but the fallback did not take this case into account. Reported-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1414148280-17949-2-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03block/curl: Improve type safety of s->timeout.Richard W.M. Jones
qemu_opt_get_number returns a uint64_t, and curl_easy_setopt expects a long (not an int). There is no warning about the latter type error because curl_easy_setopt uses a varargs argument. Store the timeout (which is a positive number of seconds) as a uint64_t. Check that the number given by the user is reasonable. Zero is permissible (meaning no timeout is enforced by cURL). Cast it to long before calling curl_easy_setopt to fix the type error. Example error message after this change has been applied: $ ./qemu-img create -f qcow2 /tmp/test.qcow2 \ -b 'json: { "file.driver":"https", "file.url":"https://foo/bar", "file.timeout":-1 }' qemu-img: /tmp/test.qcow2: Could not open 'json: { "file.driver":"https", "file.url":"https://foo/bar", "file.timeout":-1 }': timeout parameter is too large or negative: Invalid argument Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Gonglei <arei.gonglei@huawei.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03snapshot: add bdrv_drain_all() to bdrv_snapshot_delete() to avoid ↵Zhang Haoyu
concurrency problem If there are still pending i/o while deleting snapshot, because deleting snapshot is done in non-coroutine context, and the pending i/o read/write (bdrv_co_do_rw) is done in coroutine context, so it's possible to cause concurrency problem between above two operations. Add bdrv_drain_all() to bdrv_snapshot_delete() to avoid this problem. Signed-off-by: Zhang Haoyu <zhanghy@sangfor.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 201410211637596311287@sangfor.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03rbd: Add support for bdrv_invalidate_cacheAdam Crume
This fixes Ceph issue 2467: ttp://tracker.ceph.com/issues/2467 [Dropped return r in void function as suggested by Josh Durgin <josh.durgin@inktank.com>. --Stefan] Signed-off-by: Adam Crume <adamcrume@gmail.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1412880272-3154-1-git-send-email-adamcrume@gmail.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03block/parallels: fix access to not initialized memory in catalog_bitmapDenis V. Lunev
found by valgrind. Command: ./qemu-img convert -f parallels -O qcow2 1.hds 1.img Invalid read of size 4 at 0x17D0EF: parallels_co_read (parallels.c:357) by 0x11FEE4: bdrv_aio_rw_vector (block.c:4640) by 0x11FFBF: bdrv_aio_readv_em (block.c:4652) by 0x11F55F: bdrv_co_readv_em (block.c:4862) by 0x123428: bdrv_aligned_preadv (block.c:3056) by 0x1239FA: bdrv_co_do_preadv (block.c:3162) by 0x125424: bdrv_rw_co_entry (block.c:2706) by 0x155DD9: coroutine_trampoline (coroutine-ucontext.c:118) by 0x6975B6F: ??? (in /lib/x86_64-linux-gnu/libc-2.19.so) The problem is that s->catalog_bitmap is allocated/filled as gmalloc(s->catalog_size) thus index validity check must be inclusive, i.e. index >= s->catalog_size is invalid. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1412759610-2257-4-git-send-email-den@openvz.org CC: Jeff Cody <jcody@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03block/iscsi: check for oversized requestsPeter Lieven
Cancel oversized requests early. They would generate an iSCSI protocol error anyway; after having transferred possibly a lot of data over the wire. Suggested-By: Max Reitz <mreitz@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03block/iscsi: use sector_limits_lun2qemu throughout iscsi_refresh_limitsPeter Lieven
As Max pointed out there is a hidden cast from int64_t to int for all limits. So use the newly introduced sector_limits_lun2qemu for all limits received from the target. Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03block/iscsi: set max_transfer_lengthPeter Lieven
Copy the max_xfer_len from the BlockLimits VPD or use the maximum value fitting in the CDB. The helper function sector_limits_lun2qemu is introduced to convert and cap the limits from the VPD to the maximum power of two fitting in an integer; integer is the range for nb_sectors throughout the block layer. Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-23block: char devices on FreeBSD are not behind a pagerRoger Pau Monne
Introduce a new flag to mark devices that require requests to be aligned and replace the usage of BDRV_O_NOCACHE and O_DIRECT with this flag when appropriate. If a character device is used as a backend on a FreeBSD host set this flag unconditionally. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2014-10-23qcow2: Do not overflow when writing an L1 sectorMax Reitz
While writing an L1 table sector, qcow2_write_l1_entry() copies the respective range from s->l1_table to the local "buf" array. The size of s->l1_table does not have to be a multiple of L1_ENTRIES_PER_SECTOR; thus, limit the index which is used for copying all entries to the L1 size. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Peter Lieven <pl@kamp.de> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Drop REFCOUNT_SHIFTMax Reitz
With BDRVQcowState.refcount_block_bits, we don't need REFCOUNT_SHIFT anymore. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Clean up after refcount rebuildMax Reitz
Because the old refcount structure will be leaked after having rebuilt it, we need to recalculate the refcounts and run a leak-fixing operation afterwards (if leaks should be fixed at all). Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Rebuild refcount structure during checkMax Reitz
The previous commit introduced the "rebuild" variable to qcow2's implementation of the image consistency check. Now make use of this by adding a function which creates a completely new refcount structure based solely on the in-memory information gathered before. The old refcount structure will be leaked, however. This leak will be dealt with in a follow-up commit. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Do not perform potentially damaging repairsMax Reitz
If a referenced cluster has a refcount of 0, increasing its refcount may result in clusters being allocated for the refcount structures. This may overwrite the referenced cluster, therefore we cannot simply increase the refcount then. In such cases, we can either try to replicate all the refcount operations solely for the check operation, basing the allocations on the in-memory refcount table; or we can simply rebuild the whole refcount structure based on the in-memory refcount table. Since the latter will be much easier, do that. To prepare for this, introduce a "rebuild" boolean which should be set to true whenever a fix is rather dangerous or too complicated using the current refcount structures. Another example for this is refcount blocks being referenced more than once. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Fix refcount blocks beyond image endMax Reitz
If the qcow2 check function detects a refcount block located beyond the image end, grow the image appropriately. This cannot break anything and is the logical fix for such a case. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Reuse refcount table in calculate_refcounts()Max Reitz
We will later call calculate_refcounts multiple times, so reuse the refcount table if possible. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Let inc_refcounts() resize the reftableMax Reitz
Now that the refcount table can be passed around by reference, do that for inc_refcounts() (and subsequently check_refcounts_l1() and check_refcounts_l2()) and use it for resizing it when a cluster after the image end is encountered. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Let inc_refcounts() return -errnoMax Reitz
As of a future patch, inc_refcounts() will have to throw errors which are generally signaled by returning -errno. Therefore, let it return an integer which is either 0 for success or -errno and handle the -errno case in all callers. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Split fail code in L1 and L2 checksMax Reitz
Instead of printing out an error message, incrementing check_errors and returning a fixed -errno, just do cleanups and return -ret, with ret set by the code which threw the exception (jumped to the fail label). Also, increment check_errors on error in check_refcounts_l2(). Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Use int64_t for in-memory reftable sizeMax Reitz
Use int64_t for the entry count of the in-memory refcount table throughout the check functions. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Pull check_refblocks() upMax Reitz
Pull check_refblocks() before calculate_refcounts() so we can drop its static declaration. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Use sizeof(**refcount_table)Max Reitz
When implementing variable refcounts, we want to be able to easily find all the places in qemu which are tied to a certain refcount order. Replace sizeof(uint16_t) in the check code by sizeof(**refcount_table) so we can later find it more easily. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Split qcow2_check_refcounts()Max Reitz
Put the code for calculating the reference counts and comparing them during qemu-img check into own functions. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Fix leaks in dirty imagesMax Reitz
When opening dirty images, qcow2's repair function should not only repair errors but leaks as well. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23qcow2: Calculate refcount block entry countMax Reitz
The size of a refblock entry is (in theory) variable; calculate therefore the number of entries per refblock and the according bit shift (1 << x == entry count) when opening an image. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23block/vdi: Use {DIV_,}ROUND_UPMax Reitz
There are macros for these operations, so make use of them. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Make device model's references to BlockBackend strongMarkus Armbruster
Doesn't make a difference just yet, but it's the right thing to do. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Lift device model API into BlockBackendMarkus Armbruster
Move device model attachment / detachment and the BlockDevOps device model callbacks and their wrappers from BlockDriverState to BlockBackend. Wrapper calls in block.c change from bdrv_dev_FOO_cb(bs, ...) to if (bs->blk) { bdrv_dev_FOO_cb(bs->blk, ...); } No change, because both bdrv_dev_change_media_cb() and bdrv_dev_resize_cb() do nothing when no device model is attached, and a device model can be attached only when bs->blk. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block/qapi: Convert qmp_query_block() to BlockBackendMarkus Armbruster
Much more command code needs conversion. I start with this one because it's using bdrv_dev_* functions, which I'm about to lift into BlockBackend. While there, give bdrv_query_info() internal linkage. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20blockdev: Fix blockdev-add not to create DriveInfoMarkus Armbruster
blockdev_init() always creates a DriveInfo, but only drive_new() fills it in. qmp_blockdev_add() leaves it blank. This results in a drive with type = IF_IDE, bus = 0, unit = 0. Screwed up in commit ee13ed1c. Board initialization code looking for IDE drive (0,0) can pick up one of these bogus drives. The QMP command has to execute really early to be visible. Not sure how likely that is in practice. Fix by creating DriveInfo in drive_new(). Block backends created by blockdev-add don't get one. Breaks the test for "has been created by qmp_blockdev_add()" in blockdev_mark_auto_del() and do_drive_del(), because it changes the value of dinfo && !dinfo->enable_auto_del from true to false. Simply test !dinfo instead. Leaves DriveInfo member enable_auto_del unused. Drop it. A few places assume a block backend always has a DriveInfo. Fix them up. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20blockdev: Drop superfluous DriveInfo member idMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20hw: Convert from BlockDriverState to BlockBackend, mostlyMarkus Armbruster
Device models should access their block backends only through the block-backend.h API. Convert them, and drop direct includes of inappropriate headers. Just four uses of BlockDriverState are left: * The Xen paravirtual block device backend (xen_disk.c) opens images itself when set up via xenbus, bypassing blockdev.c. I figure it should go through qmp_blockdev_add() instead. * Device model "usb-storage" prompts for keys. No other device model does, and this one probably shouldn't do it, either. * ide_issue_trim_cb() uses bdrv_aio_discard() instead of blk_aio_discard() because it fishes its backend out of a BlockAIOCB, which has only the BlockDriverState. * PC87312State has an unused BlockDriverState[] member. The next two commits take care of the latter two. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Rename BlockDriverCompletionFunc to BlockCompletionFuncMarkus Armbruster
I'll use it with block backends shortly, and the name is going to fit badly there. It's a block layer thing anyway, not just a block driver thing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Rename BlockDriverAIOCB* to BlockAIOCB*Markus Armbruster
I'll use BlockDriverAIOCB with block backends shortly, and the name is going to fit badly there. It's a block layer thing anyway, not just a block driver thing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Merge BlockBackend and BlockDriverState name spacesMarkus Armbruster
BlockBackend's name space is separate only to keep the initial patches simple. Time to merge the two. Retain bdrv_find() and bdrv_get_device_name() for now, to keep this series manageable. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Eliminate BlockDriverState member device_name[]Markus Armbruster
device_name[] can become non-empty only in bdrv_new_root() and bdrv_move_feature_fields(). The latter is used only to undo damage done by bdrv_swap(). The former is called only by blk_new_with_bs(). Therefore, when a BlockDriverState's device_name[] is non-empty, then it's been created with a BlockBackend, and vice versa. Furthermore, blk_new_with_bs() keeps the two names equal. Therefore, device_name[] is redundant. Eliminate it. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Make BlockBackend own its BlockDriverStateMarkus Armbruster
On BlockBackend destruction, unref its BlockDriverState. Replaces the callers' unrefs. This turns the pointer from BlockBackend to BlockDriverState into a strong reference, managed with bdrv_ref() / bdrv_unref(). The back-pointer remains weak. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Code motion to get rid of stubs/blockdev.cMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Connect BlockBackend and DriveInfoMarkus Armbruster
Make the BlockBackend own the DriveInfo. Change blockdev_init() to return the BlockBackend instead of the DriveInfo. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Connect BlockBackend to BlockDriverStateMarkus Armbruster
Convenience function blk_new_with_bs() creates a BlockBackend with its BlockDriverState. Callers have to unref both. The commit after next will relieve them of the need to unref the BlockDriverState. Complication: due to the silly way drive_del works, we need a way to hide a BlockBackend, just like bdrv_make_anon(). To emphasize its "special" status, give the function a suitably off-putting name: blk_hide_on_behalf_of_do_drive_del(). Unfortunately, hiding turns the BlockBackend's name into the empty string. Can't avoid that without breaking the blk->bs->device_name equals blk->name invariant. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: New BlockBackendMarkus Armbruster
A block device consists of a frontend device model and a backend. A block backend has a tree of block drivers doing the actual work. The tree is managed by the block layer. We currently use a single abstraction BlockDriverState both for tree nodes and the backend as a whole. Drawbacks: * Its API includes both stuff that makes sense only at the block backend level (root of the tree) and stuff that's only for use within the block layer. This makes the API bigger and more complex than necessary. Moreover, it's not obvious which interfaces are meant for device models, and which really aren't. * Since device models keep a reference to their backend, the backend object can't just be destroyed. But for media change, we need to replace the tree. Our solution is to make the BlockDriverState generic, with actual driver state in a separate object, pointed to by member opaque. That lets us replace the tree by deinitializing and reinitializing its root. This special need of the root makes the data structure awkward everywhere in the tree. The general plan is to separate the APIs into "block backend", for use by device models, monitor and whatever other code dealing with block backends, and "block driver", for use by the block layer and whatever other code (if any) dealing with trees and tree nodes. Code dealing with block backends, device models in particular, should become completely oblivious of BlockDriverState. This should let us clean up both APIs, and the tree data structures. This commit is a first step. It creates a minimal "block backend" API: type BlockBackend and functions to create, destroy and find them. BlockBackend objects are created and destroyed exactly when root BlockDriverState objects are created and destroyed. "Root" in the sense of "in bdrv_states". They're not yet used for anything; that'll come shortly. A root BlockDriverState is created with bdrv_new_root(), so where to create a BlockBackend is obvious. Where these roots get destroyed isn't always as obvious. It is obvious in qemu-img.c, qemu-io.c and qemu-nbd.c, and in error paths of blockdev_init(), blk_connect(). That leaves destruction of objects successfully created by blockdev_init() and blk_connect(). blockdev_init() is used only by drive_new() and qmp_blockdev_add(). Objects created by the latter are currently indestructible (see commit 48f364d "blockdev: Refuse to drive_del something added with blockdev-add" and commit 2d246f0 "blockdev: Introduce DriveInfo.enable_auto_del"). Objects created by the former get destroyed by drive_del(). Objects created by blk_connect() get destroyed by blk_disconnect(). BlockBackend is reference-counted. Its reference count never exceeds one so far, but that's going to change. In drive_del(), the BB's reference count is surely one now. The BDS's reference count is greater than one when something else is holding a reference, such as a block job. In this case, the BB is destroyed right away, but the BDS lives on until all extra references get dropped. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Split bdrv_new_root() off bdrv_new()Markus Armbruster
Creating an anonymous BDS can't fail. Make that obvious. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20nbd: Fix filename generationMax Reitz
Export names may be used with nbd+unix, too, fix nbd_refresh_filename() accordingly. Also, for nbd+tcp, the documented path schema is "nbd://host[:port]/export", so use it. Furthermore, as can be seen from that schema, the port is optional. That makes six single cases for how the filename can be formatted; it is not easy to generalize these cases without the resulting statement being completely unreadable, thus there is simply one snprintf() per case. Finally, taking the options from BDRVNBDState::socket_opts is wrong, because those will not contain the export name. Just use BlockDriverState::options instead. Reported-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>