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39097daf15
Hosts hold on to handles provided by guest-file-open for periods that can span beyond the life of the qemu-ga process that issued them. Since these are issued starting from 0 on every restart, we run the risk of issuing duplicate handles after restarts/reboots. As a result, users with a stale copy of these handles may end up reading/writing corrupted data due to their existing handles effectively being re-assigned to an unexpected file or offset. We unfortunately do not issue handles as strings, but as integers, so a solution such as using UUIDs can't be implemented without introducing a new interface. As a workaround, we fix this by implementing a persistent key-value store that will be used to track the value of the last handle that was issued across restarts/reboots to avoid issuing duplicates. The store is automatically written to the same directory we currently set via --statedir to track fsfreeze state, and so should be applicable for stable releases where this flag is supported. A follow-up can use this same store for handling fsfreeze state, but that change is cosmetic and left out for now. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Cc: qemu-stable@nongnu.org * fixed guest_file_handle_add() return value from uint64_t to int64_t
43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/*
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* QEMU Guest Agent core declarations
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*
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* Copyright IBM Corp. 2011
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*
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* Authors:
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* Adam Litke <aglitke@linux.vnet.ibm.com>
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* Michael Roth <mdroth@linux.vnet.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qapi/qmp/dispatch.h"
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#include "qemu-common.h"
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#define QGA_READ_COUNT_DEFAULT 4096
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typedef struct GAState GAState;
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typedef struct GACommandState GACommandState;
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extern GAState *ga_state;
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void ga_command_state_init(GAState *s, GACommandState *cs);
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void ga_command_state_add(GACommandState *cs,
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void (*init)(void),
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void (*cleanup)(void));
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void ga_command_state_init_all(GACommandState *cs);
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void ga_command_state_cleanup_all(GACommandState *cs);
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GACommandState *ga_command_state_new(void);
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bool ga_logging_enabled(GAState *s);
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void ga_disable_logging(GAState *s);
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void ga_enable_logging(GAState *s);
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void slog(const gchar *fmt, ...);
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void ga_set_response_delimited(GAState *s);
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bool ga_is_frozen(GAState *s);
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void ga_set_frozen(GAState *s);
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void ga_unset_frozen(GAState *s);
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const char *ga_fsfreeze_hook(GAState *s);
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int64_t ga_get_fd_handle(GAState *s, Error **errp);
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#ifndef _WIN32
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void reopen_fd_to_null(int fd);
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#endif
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