ib_alloc.c (1725B)
1 /* 2 * Copyright (c) 2003 Gunnar Ritter 3 * 4 * This software is provided 'as-is', without any express or implied 5 * warranty. In no event will the authors be held liable for any damages 6 * arising from the use of this software. 7 * 8 * Permission is granted to anyone to use this software for any purpose, 9 * including commercial applications, and to alter it and redistribute 10 * it freely, subject to the following restrictions: 11 * 12 * 1. The origin of this software must not be misrepresented; you must not 13 * claim that you wrote the original software. If you use this software 14 * in a product, an acknowledgment in the product documentation would be 15 * appreciated but is not required. 16 * 17 * 2. Altered source versions must be plainly marked as such, and must not be 18 * misrepresented as being the original software. 19 * 20 * 3. This notice may not be removed or altered from any source distribution. 21 */ 22 /* Sccsid @(#)ib_alloc.c 1.5 (gritter) 3/12/05 */ 23 24 #include <sys/types.h> 25 #include <sys/stat.h> 26 #include <fcntl.h> 27 #include <unistd.h> 28 #include <string.h> 29 #include <errno.h> 30 #include <stdlib.h> 31 #include <malloc.h> 32 33 #include "memalign.h" 34 #include "iblok.h" 35 36 struct iblok * 37 ib_alloc(int fd, unsigned blksize) 38 { 39 static long pagesize; 40 struct iblok *ip; 41 struct stat st; 42 43 if (pagesize == 0) 44 if ((pagesize = sysconf(_SC_PAGESIZE)) < 0) 45 pagesize = 4096; 46 if (blksize == 0) { 47 if (fstat(fd, &st) < 0) 48 return NULL; 49 blksize = st.st_blksize > 0 ? st.st_blksize : 512; 50 } 51 if ((ip = calloc(1, sizeof *ip)) == NULL) 52 return NULL; 53 if ((ip->ib_blk = memalign(pagesize, blksize)) == NULL) { 54 free(ip); 55 return NULL; 56 } 57 ip->ib_blksize = blksize; 58 ip->ib_fd = fd; 59 ip->ib_mb_cur_max = MB_CUR_MAX; 60 return ip; 61 }