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c33159dec7
This patch is purely mechanical, changing bool want_zero into an unsigned int for bitwise-or of flags. As of this patch, all implementations are unchanged (the old want_zero==true is now mode==BDRV_WANT_PRECISE which is a superset of BDRV_WANT_ZERO); but the callers in io.c that used to pass want_zero==false are now prepared for future driver changes that can now distinguish bewteen BDRV_WANT_ZERO vs. BDRV_WANT_ALLOCATED. The next patch will actually change the file-posix driver along those lines, now that we have more-specific hints. As for the background why this patch is useful: right now, the file-posix driver recognizes that if allocation is being queried, the entire image can be reported as allocated (there is no backing file to refer to) - but this throws away information on whether the entire image reads as zero (trivially true if lseek(SEEK_HOLE) at offset 0 returns -ENXIO, a bit more complicated to prove if the raw file was created with 'qemu-img create' since we intentionally allocate a small chunk of all-zero data to help with alignment probing). Later patches will add a generic algorithm for seeing if an entire file reads as zeroes. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20250509204341.3553601-16-eblake@redhat.com>
92 lines
3.4 KiB
C
92 lines
3.4 KiB
C
/*
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* Block layer I/O functions
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*
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* Copyright (c) 2003 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#ifndef BLOCK_COROUTINES_H
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#define BLOCK_COROUTINES_H
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#include "block/block_int.h"
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/* For blk_bs() in generated block/block-gen.c */
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#include "system/block-backend.h"
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/*
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* I/O API functions. These functions are thread-safe.
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*
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* See include/block/block-io.h for more information about
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* the I/O API.
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*/
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int coroutine_fn GRAPH_RDLOCK
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bdrv_co_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
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int coroutine_fn GRAPH_RDLOCK
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bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp);
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int coroutine_fn GRAPH_RDLOCK
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bdrv_co_common_block_status_above(BlockDriverState *bs,
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BlockDriverState *base,
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bool include_base,
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unsigned int mode,
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int64_t offset,
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int64_t bytes,
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int64_t *pnum,
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int64_t *map,
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BlockDriverState **file,
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int *depth);
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int coroutine_fn GRAPH_RDLOCK
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bdrv_co_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
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int coroutine_fn GRAPH_RDLOCK
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bdrv_co_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
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int coroutine_fn GRAPH_RDLOCK
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nbd_co_do_establish_connection(BlockDriverState *bs, bool blocking,
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Error **errp);
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/*
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* "I/O or GS" API functions. These functions can run without
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* the BQL, but only in one specific iothread/main loop.
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*
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* See include/block/block-io.h for more information about
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* the "I/O or GS" API.
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*/
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int co_wrapper_mixed_bdrv_rdlock
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bdrv_common_block_status_above(BlockDriverState *bs,
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BlockDriverState *base,
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bool include_base,
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unsigned int mode,
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int64_t offset,
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int64_t bytes,
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int64_t *pnum,
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int64_t *map,
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BlockDriverState **file,
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int *depth);
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int co_wrapper_mixed_bdrv_rdlock
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nbd_do_establish_connection(BlockDriverState *bs, bool blocking, Error **errp);
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#endif /* BLOCK_COROUTINES_H */
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