Messages in this thread | | | Date | Mon, 11 Apr 2005 21:14:17 +0200 | From | Yves Crespin <> | Subject | read failed EINVAL with O_DIRECT flag |
| |
Hello,
Using O_DIRECT flag, read() failed and errno is EINVAL. kernel 2.4.22 Filesystem Ext3 mount on /home What's wrong ? Thanks
Yves Crespin
#gcc -Wall -D_GNU_SOURCE direct.c -o direct #cp direct d #./direct d #open failed [d] 040402 0666 errno 22 #
/* --- start code --- */ #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <errno.h>
#define O_BINARY 0
int main(int argc,char *argv[]) { struct stat sbuf; char buf[8192]; int openFlags; int fd; int nb; int size;
if (argc!=2){ printf("Missing file name\n"); exit(2); } openFlags = O_RDWR|O_BINARY|O_NOCTTY; openFlags |= O_DIRECT; /* Not POSIX */ fd = open(argv[1],openFlags,0666); if (fd==-1){ printf("open failed [%s] %#o %#o errno %d\n",argv[1],openFlags,0666,errno); exit(1); } if (fstat(fd,&sbuf)<0){ printf("fstat failed\n"); exit(1); } size = sbuf.st_blksize; if (size > sizeof(buf)){ printf("Page size too big\n"); exit(3); } if (size > sbuf.st_size){ printf("File too small\n"); exit(3); } nb = read(fd,buf,size); if (nb != size){ printf("read failed fd %d size %d nb %d errno %d\n",fd,size,nb,errno); exit(1); } if (close(fd)){ printf("close failed\n"); exit(1); } return 0; } /* --- end code --- */
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |