Author: delphij Date: Sun Jul 5 00:19:08 2020 New Revision: 362937 URL: https://svnweb.freebsd.org/changeset/base/362937
Log: Use KERN_MAXPHYS. Suggested by: imp Reviewed by: imp, cem (earlier version), emaste MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D25563 Modified: head/sbin/newfs_msdos/mkfs_msdos.c Modified: head/sbin/newfs_msdos/mkfs_msdos.c ============================================================================== --- head/sbin/newfs_msdos/mkfs_msdos.c Sat Jul 4 18:37:04 2020 (r362936) +++ head/sbin/newfs_msdos/mkfs_msdos.c Sun Jul 5 00:19:08 2020 (r362937) @@ -41,8 +41,10 @@ static const char rcsid[] = #include <sys/mount.h> #endif #include <sys/stat.h> +#include <sys/sysctl.h> #include <sys/time.h> +#include <assert.h> #include <ctype.h> #include <err.h> #include <errno.h> @@ -78,25 +80,6 @@ static const char rcsid[] = #define MAXCLS16 0xfff4U /* maximum FAT16 clusters */ #define MAXCLS32 0xffffff4U /* maximum FAT32 clusters */ -#ifndef CTASSERT -#define CTASSERT(x) _CTASSERT(x, __LINE__) -#define _CTASSERT(x, y) __CTASSERT(x, y) -#define __CTASSERT(x, y) typedef char __assert_ ## y [(x) ? 1 : -1] -#endif - -/* - * For better performance, we want to write larger chunks instead of - * individual sectors (the size can only be 512, 1024, 2048 or 4096 - * bytes). Assert that MAXPHYS can always hold an integer number of - * sectors by asserting that both are power of two numbers and the - * MAXPHYS is greater than MAXBPS. - */ -CTASSERT(powerof2(MAXPHYS)); -CTASSERT(powerof2(MAXBPS)); -CTASSERT(MAXPHYS > MAXBPS); - -const static ssize_t chunksize = MAXPHYS; - #define mincls(fat) ((fat) == 12 ? MINCLS12 : \ (fat) == 16 ? MINCLS16 : \ MINCLS32) @@ -240,6 +223,7 @@ static volatile sig_atomic_t got_siginfo; static void infohandler(int); static int check_mounted(const char *, mode_t); +static ssize_t getchunksize(void); static int getstdfmt(const char *, struct bpb *); static int getdiskinfo(int, const char *, const char *, int, struct bpb *); static void print_bpb(struct bpb *); @@ -272,6 +256,7 @@ mkfs_msdos(const char *fname, const char *dtype, const bool set_res, set_spf, set_spc; int fd, fd1, rv; struct msdos_options o = *op; + ssize_t chunksize; physbuf = NULL; rv = -1; @@ -640,6 +625,7 @@ mkfs_msdos(const char *fname, const char *dtype, const tm = localtime(&now); } + chunksize = getchunksize(); physbuf = malloc(chunksize); if (physbuf == NULL) { warn(NULL); @@ -848,6 +834,47 @@ check_mounted(const char *fname, mode_t mode) } #endif return 0; +} + +/* + * Get optimal I/O size + */ +static ssize_t +getchunksize(void) +{ + static int chunksize; + + if (chunksize != 0) + return ((ssize_t)chunksize); + +#ifdef KERN_MAXPHYS + int mib[2]; + size_t len; + + mib[0] = CTL_KERN; + mib[1] = KERN_MAXPHYS; + len = sizeof(chunksize); + + if (sysctl(mib, 2, &chunksize, &len, NULL, 0) == -1) { + warn("sysctl: KERN_MAXPHYS, using %zu", (size_t)MAXPHYS); + chunksize = 0; + } +#endif + if (chunksize == 0) + chunksize = MAXPHYS; + + /* + * For better performance, we want to write larger chunks instead of + * individual sectors (the size can only be 512, 1024, 2048 or 4096 + * bytes). Assert that chunksize can always hold an integer number of + * sectors by asserting that both are power of two numbers and the + * chunksize is greater than MAXBPS. + */ + static_assert(powerof2(MAXBPS), "MAXBPS is not power of 2"); + assert(powerof2(chunksize)); + assert(chunksize > MAXBPS); + + return ((ssize_t)chunksize); } /* _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
