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	With the built-in tables __NR_preadv2 and __NR_pwritev2 are always defined. The kernel has never defined __NR_preadv64v2 and __NR_pwritev64v2 and is unlikely to do so, given that the preadv2 and pwritev2 system calls themselves are 64-bit. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
		
			
				
	
	
		
			54 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			54 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Linux implementation of preadv2.
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|    Copyright (C) 2017-2020 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library; if not, see
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|    <https://www.gnu.org/licenses/>.  */
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| 
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| #include <sys/uio.h>
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| #include <sysdep-cancel.h>
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| 
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| #ifndef __OFF_T_MATCHES_OFF64_T
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| 
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| ssize_t
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| preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
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| 	 int flags)
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| {
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|   ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
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| 				   LO_HI_LONG (offset), flags);
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|   if (result >= 0 || errno != ENOSYS)
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|     return result;
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| 
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|   /* Trying to emulate the preadv2 syscall flags is troublesome:
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| 
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|      * We can not temporary change the file state of the O_DSYNC and O_SYNC
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|        flags to emulate RWF_{D}SYNC (attempts to change the state of using
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|        fcntl are silently ignored).
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| 
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|      * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
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|        semantic not provided by any other flag (O_NONBLOCK for instance).  */
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| 
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|   if (flags != 0)
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|     {
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|       __set_errno (ENOTSUP);
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|       return -1;
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|     }
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|   if (offset == -1)
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|     return __readv (fd, vector, count);
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|   else
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|     return preadv (fd, vector, count, offset);
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| }
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| 
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| #endif
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