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* block: use int64_t instead of uint64_t in driver read handlersVladimir Sementsov-Ogievskiy2021-09-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver read handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_preadv() in block/io.c, passes int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_load_vmstate() does bdrv_check_qiov_request(). do_perform_cow_read() has uint64_t argument. And a lot of things in qcow2 driver are uint64_t, so converting it is big job. But we must not work with requests that don't satisfy bdrv_check_qiov_request(), so let's just assert it here. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done The only one such caller: QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); ... ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); in tests/unit/test-bdrv-drain.c, and it's OK obviously. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: fix typos] Signed-off-by: Eric Blake <eblake@redhat.com>
* block: Use bdrv_default_perms()Max Reitz2020-05-181-1/+1
| | | | | | | | | | | | | | | | | | bdrv_default_perms() can decide which permission profile to use based on the BdrvChildRole, so block drivers do not need to select it explicitly. The blkverify driver now no longer shares the WRITE permission for the image to verify. We thus have to adjust two places in test-block-iothread not to take it. (Note that in theory, blkverify should behave like quorum in this regard and share neither WRITE nor RESIZE for both of its children. In practice, it does not really matter, because blkverify is used only for debugging, so we might as well keep its permissions rather liberal.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-30-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Make format drivers use child_of_bdsMax Reitz2020-05-181-2/+2
| | | | | | | | | | | Commonly, they need to pass the BDRV_CHILD_IMAGE set as the BdrvChildRole; but there are exceptions for drivers with external data files (qcow2 and vmdk). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-26-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Add BdrvChildRole to BdrvChildMax Reitz2020-05-181-1/+1
| | | | | | | | | | For now, it is always set to 0. Later patches in this series will ensure that all callers pass an appropriate combination of flags. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-6-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Add BlockDriver.is_formatMax Reitz2020-05-181-0/+1
| | | | | | | | | | | | | | | We want to unify child_format and child_file at some point. One of the important things that set format drivers apart from other drivers is that they do not expect other format nodes under them (except in the backing chain), i.e. we must not probe formats inside of formats. That means we need something on which to distinguish format drivers from others, and hence this flag. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200513110544.176672-3-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Use QEMU_IS_ALIGNEDNir Soffer2019-09-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | Replace instances of: (n & (BDRV_SECTOR_SIZE - 1)) == 0 And: (n & ~BDRV_SECTOR_MASK) == 0 With: QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE) Which reveals the intent of the code better, and makes it easier to locate the code checking alignment. Signed-off-by: Nir Soffer <nsoffer@redhat.com> Message-id: 20190827185913.27427-2-nsoffer@redhat.com Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* Include qemu-common.h exactly where neededMarkus Armbruster2019-06-121-1/+0Star
| | | | | | | | | | | | | | | | No header includes qemu-common.h after this commit, as prescribed by qemu-common.h's file comment. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190523143508.25387-5-armbru@redhat.com> [Rebased with conflicts resolved automatically, except for include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and net/tap-bsd.c fixed up]
* block: Require auto-read-only for existing fallbacksKevin Wolf2018-11-051-11/+5Star
| | | | | | | | | | | | | | | | Some block drivers have traditionally changed their node to read-only mode without asking the user. This behaviour has been marked deprecated since 2.11, expecting users to provide an explicit read-only=on option. Now that we have auto-read-only=on, enable these drivers to make use of the option. This is the only use of bdrv_set_read_only(), so we can make it a bit more specific and turn it into a bdrv_apply_auto_read_only() that is more convenient for drivers to use. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
* block: Deprecate bdrv_set_read_only() and usersKevin Wolf2017-11-171-3/+10
| | | | | | | | | | | | | | bdrv_set_read_only() is used by some block drivers to override the read-only option given by the user. This is not how read-only images generally work in QEMU: Instead of second guessing what the user really meant (which currently includes making an image read-only even if the user didn't only use the default, but explicitly said read-only=off), we should error out if we can't provide what the user requested. This adds deprecation warnings to all callers of bdrv_set_read_only() so that the behaviour can be corrected after the usual deprecation period. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: do not set BDS read_only if copy_on_read enabledJeff Cody2017-04-241-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | A few block drivers will set the BDS read_only flag from their .bdrv_open() function. This means the bs->read_only flag could be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ flag check occurs prior to the call to bdrv->bdrv_open(). This adds an error return to bdrv_set_read_only(), and an error will be return if we try to set the BDS to read_only while copy_on_read is enabled. This patch also changes the behavior of vvfat. Before, vvfat could override the drive 'readonly' flag with its own, internal 'rw' flag. For instance, this -drive parameter would result in a writable image: "-drive format=vvfat,dir=/tmp/vvfat,rw,if=virtio,readonly=on" This is not correct. Now, attempting to use the above -drive parameter will result in an error (i.e., 'rw' is incompatible with 'readonly=on'). Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 0c5b4c1cc2c651471b131f21376dfd5ea24d2196.1491597120.git.jcody@redhat.com
* block: add bdrv_set_read_only() helper functionJeff Cody2017-04-241-1/+1
| | | | | | | | | | We have a helper wrapper for checking for the BDS read_only flag, add a helper wrapper to set the read_only flag as well. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 9b18972d05f5fa2ac16c014f0af98d680553048d.1491597120.git.jcody@redhat.com
* block: Request child permissions in format driversKevin Wolf2017-02-281-0/+1
| | | | | | | | | | | | | | This makes use of the .bdrv_child_perm() implementation for formats that we just added. All format drivers expose the permissions they actually need nows, so that they can be set accordingly and updated when parents are attached or detached. The only format not included here is raw, which was already converted with the other filter drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
* block: Attach bs->file only during .bdrv_open()Kevin Wolf2017-02-241-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | The way that attaching bs->file worked was a bit unusual in that it was the only child that would be attached to a node which is not opened yet. Because of this, the block layer couldn't know yet which permissions the driver would eventually need. This patch moves the point where bs->file is attached to the beginning of the individual .bdrv_open() implementations, so drivers already know what they are going to do with the child. This is also more consistent with how driver-specific children work. For a moment, bdrv_open() gets its own BdrvChild to perform image probing, but instead of directly assigning this BdrvChild to the BDS, it becomes a temporary one and the node name is passed as an option to the drivers, so that they can simply use bdrv_open_child() to create another reference for their own use. This duplicated child for (the not opened yet) bs is not the final state, a follow-up patch will change the image probing code to use a BlockBackend, which is completely independent of bs. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* block: Convert bdrv_pread(v) to BdrvChildKevin Wolf2016-07-051-4/+4
| | | | | | Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: Use bool as appropriate for BDS membersEric Blake2016-07-051-1/+1
| | | | | | | | | | Using int for values that are only used as booleans is confusing. While at it, rearrange a couple of members so that all the bools are contiguous. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Move request_alignment into BlockLimitEric Blake2016-07-051-1/+1
| | | | | | | | | | | | It makes more sense to have ALL block size limit constraints in the same struct. Improve the documentation while at it. Simplify a couple of conditionals, now that we have audited and documented that request_alignment is always non-zero. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Set request_alignment during .bdrv_refresh_limits()Eric Blake2016-07-051-1/+6
| | | | | | | | | | | | | | | | We want to eventually stick request_alignment alongside other BlockLimits, but first, we must ensure it is populated at the same time as all other limits, rather than being a special case that is set only when a block is first opened. Add a .bdrv_refresh_limits() to all four of our legacy devices that will always be sector-only (bochs, cloop, dmg, vvfat), in spite of their recent conversion to expose a byte interface. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qemu-common: stop including qemu/bswap.h from qemu-common.hPaolo Bonzini2016-05-191-0/+1
| | | | | | | Move it to the actual users. There are still a few includes of qemu/bswap.h in headers; removing them is left for future work. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* cloop: Implement .bdrv_co_preadv() interfaceKevin Wolf2016-05-121-16/+22
| | | | | | | | | This implements .bdrv_co_preadv() for the cloop block driver. While updating the error paths, change -1 to a valid -errno code. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
* include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster2016-03-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* block: Clean up includesPeter Maydell2016-01-201-0/+1
| | | | | | | | | | | Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Convert bs->file to BdrvChildKevin Wolf2015-10-161-5/+5
| | | | | | | | | | | This patch removes the temporary duplication between bs->file and bs->file_child by converting everything to BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
* cloop: Handle failure for potentially large allocationsKevin Wolf2014-08-151-3/+20
| | | | | | | | | | | | Some code in the block layer makes potentially huge allocations. Failure is not completely unexpected there, so avoid aborting qemu and handle out-of-memory situations gracefully. This patch addresses the allocations in the cloop block driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>
* block/cloop: use PRIu32 format specifier for uint32_tStefan Hajnoczi2014-04-231-6/+6
| | | | | | | | | PRIu32 is the format string specifier for uint32_t, let's use it. Variables ->block_size, ->n_blocks, and i are all uint32_t. Suggested-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block/cloop: fix offsets[] size off-by-oneStefan Hajnoczi2014-04-011-7/+5Star
| | | | | | | | | | | | | | | | | | | | | | cloop stores the number of compressed blocks in the n_blocks header field. The file actually contains n_blocks + 1 offsets, where the extra offset is the end-of-file offset. The following line in cloop_read_block() results in an out-of-bounds offsets[] access: uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num]; This patch allocates and loads the extra offset so that cloop_read_block() works correctly when the last block is accessed. Notice that we must free s->offsets[] unconditionally now since there is always an end-of-file offset. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block/cloop: refuse images with bogus offsets (CVE-2014-0144)Stefan Hajnoczi2014-04-011-5/+29
| | | | | | | | | | | | | | The offsets[] array allows efficient seeking and tells us the maximum compressed data size. If the offsets are bogus the maximum compressed data size will be unrealistic. This could cause g_malloc() to abort and bogus offsets mean the image is broken anyway. Therefore we should refuse such images. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block/cloop: refuse images with huge offsets arrays (CVE-2014-0144)Stefan Hajnoczi2014-04-011-0/+9
| | | | | | | | | | | | | | | Limit offsets_size to 512 MB so that: 1. g_malloc() does not abort due to an unreasonable size argument. 2. offsets_size does not overflow the bdrv_pread() int size argument. This limit imposes a maximum image size of 16 TB at 256 KB block size. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block/cloop: prevent offsets_size integer overflow (CVE-2014-0143)Stefan Hajnoczi2014-04-011-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following integer overflow in offsets_size can lead to out-of-bounds memory stores when n_blocks has a huge value: uint32_t n_blocks, offsets_size; [...] ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4); [...] s->n_blocks = be32_to_cpu(s->n_blocks); /* read offsets */ offsets_size = s->n_blocks * sizeof(uint64_t); s->offsets = g_malloc(offsets_size); [...] for(i=0;i<s->n_blocks;i++) { s->offsets[i] = be64_to_cpu(s->offsets[i]); offsets_size can be smaller than n_blocks due to integer overflow. Therefore s->offsets[] is too small when the for loop byteswaps offsets. This patch refuses to open files if offsets_size would overflow. Note that changing the type of offsets_size is not a fix since 32-bit hosts still only have 32-bit size_t. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block/cloop: validate block_size header field (CVE-2014-0144)Stefan Hajnoczi2014-04-011-0/+23
| | | | | | | | | | | | | | Avoid unbounded s->uncompressed_block memory allocation by checking that the block_size header field has a reasonable value. Also enforce the assumption that the value is a non-zero multiple of 512. These constraints conform to cloop 2.639's code so we accept existing image files. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* bdrv: Use "Error" for opening imagesMax Reitz2013-09-121-1/+2
| | | | | | | Add an Error ** parameter to BlockDriver.bdrv_open and BlockDriver.bdrv_file_open to allow more specific error messages. Signed-off-by: Max Reitz <mreitz@redhat.com>
* block: Add options QDict to .bdrv_open()Kevin Wolf2013-03-151-1/+1
| | | | | | | Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* cloop: Fix bdrv_open() error handlingKevin Wolf2013-02-011-10/+19
| | | | | | | | Return -errno instead of -1 on errors. While touching the code, fix a memory leak. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* misc: move include files to include/qemu/Paolo Bonzini2012-12-191-1/+1
| | | | Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* block: move include files to include/block/Paolo Bonzini2012-12-191-1/+1
| | | | Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* block/cloop: Use g_free instead of freeDong Xu Wang2011-11-041-3/+3
| | | | | | | | | | Fix mismatching allocation and deallocation: g_free should be used to pair with g_malloc. Reviewed-by: Andreas Färber <afaerber@suse.de> Reviewed_by: Ray Wang <raywang@linux.vnet.ibm.com> Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block/cloop: Fix coding styleDong Xu Wang2011-11-041-52/+63
| | | | | | | | | Fix coding style in block/cloop.c. Reviewed-by: Andreas Färber <afaerber@suse.de> Reviewed_by: Ray Wang <raywang@linux.vnet.ibm.com> Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: take lock around bdrv_read implementationsPaolo Bonzini2011-10-211-1/+12
| | | | | | | | | | | | | | | | This does the first part of the conversion to coroutines, by wrapping bdrv_read implementations to take the mutex. Drivers that implement bdrv_read rather than bdrv_co_readv can then benefit from asynchronous operation (at least if the underlying protocol supports it, which is not the case for raw-win32), even though they still operate with a bounce buffer. raw-win32 does not need the lock, because it cannot yield. nbd also doesn't probably, but better be safe. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: add a CoMutex to synchronous read driversPaolo Bonzini2011-10-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The big conversion of bdrv_read/write to coroutines caused the two homonymous callbacks in BlockDriver to become reentrant. It goes like this: 1) bdrv_read is now called in a coroutine, and calls bdrv_read or bdrv_pread. 2) the nested bdrv_read goes through the fast path in bdrv_rw_co_entry; 3) in the common case when the protocol is file, bdrv_co_do_readv calls bdrv_co_readv_em (and from here goes to bdrv_co_io_em), which yields until the AIO operation is complete; 4) if bdrv_read had been called from a bottom half, the main loop is free to iterate again: a device model or another bottom half can then come and call bdrv_read again. This applies to all four of read/write/flush/discard. It would also apply to is_allocated, but it is not used from within coroutines: besides qemu-img.c and qemu-io.c, which operate synchronously, the only user is the monitor. Copy-on-read will introduce a use in the block layer, and will require converting it. The solution is "simply" to convert all drivers to coroutines! We just need to add a CoMutex that is taken around affected operations. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* Use glib memory allocation and free functionsAnthony Liguori2011-08-211-3/+3
| | | | | | qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
* cloop: use qemu block APIChristoph Hellwig2010-05-171-14/+12Star
| | | | | | | | | Use bdrv_pwrite to access the backing device instead of pread, and convert the driver to implementing the bdrv_open method which gives it an already opened BlockDriverState for the underlying device. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* cloop: use preadChristoph Hellwig2010-05-171-15/+17
| | | | | | | | Use pread instead of lseek + read in preparation of using the qemu block API. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Open the underlying image file in generic codeKevin Wolf2010-05-031-1/+1
| | | | | | | | | | | | | | | Format drivers shouldn't need to bother with things like file names, but rather just get an open BlockDriverState for the underlying protocol. This patch introduces this behaviour for bdrv_open implementation. For protocols which need to access the filename to open their file/device/connection/... a new callback bdrv_file_open is introduced which doesn't get an underlying file opened. For now, also some of the more obscure formats use bdrv_file_open because they open() the file themselves instead of using the block.c functions. They need to be fixed in later patches. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* Move block drivers into their own directoryAnthony Liguori2009-05-141-0/+171
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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