[thirdparty/xfsprogs-dev.git] / io / fadvise.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */

#include "command.h"
#include "input.h"
#include "init.h"
#include "io.h"

static cmdinfo_t fadvise_cmd;

static void
fadvise_help(void)
{
	printf(_(
"\n"
" advise the page cache about expected I/O patterns on the current file\n"
"\n"
" Modifies kernel page cache behaviour when operating on the current file.\n"
" The range arguments are required by some advise commands ([*] below).\n"
" With no arguments, the POSIX_FADV_NORMAL advice is implied.\n"
" -d -- don't need these pages (POSIX_FADV_DONTNEED) [*]\n"
" -n -- data will be accessed once (POSIX_FADV_NOREUSE) [*]\n"
" -r -- expect random page references (POSIX_FADV_RANDOM)\n"
" -s -- expect sequential page references (POSIX_FADV_SEQUENTIAL)\n"
" -w -- will need these pages (POSIX_FADV_WILLNEED) [*]\n"
" Notes: these interfaces are not supported in Linux kernels before 2.6.\n"
"   NORMAL sets the default readahead setting on the file.\n"
"   RANDOM sets the readahead setting on the file to zero.\n"
"   SEQUENTIAL sets double the default readahead setting on the file.\n"
"   WILLNEED and NOREUSE are equivalent, and force the maximum readahead.\n"
"\n"));
}

static int
fadvise_f(
	int		argc,
	char		**argv)
{
	off_t		offset = 0, length = 0;
	int		c, range = 0, advise = POSIX_FADV_NORMAL;

	while ((c = getopt(argc, argv, "dnrsw")) != EOF) {
		switch (c) {
		case 'd':	/* Don't need these pages */
			advise = POSIX_FADV_DONTNEED;
			range = 1;
			break;
		case 'n':	/* Data will be accessed once */
			advise = POSIX_FADV_NOREUSE;
			range = 1;
			break;
		case 'r':	/* Expect random page references */
			advise = POSIX_FADV_RANDOM;
			range = 0;
			break;
		case 's':	/* Expect sequential page references */
			advise = POSIX_FADV_SEQUENTIAL;
			range = 0;
			break;
		case 'w':	/* Will need these pages */
			advise = POSIX_FADV_WILLNEED;
			range = 1;
			break;
		default:
			exitcode = 1;
			return command_usage(&fadvise_cmd);
		}
	}
	if (range) {
		size_t	blocksize, sectsize;

		if (optind != argc - 2) {
			exitcode = 1;
			return command_usage(&fadvise_cmd);
		}
		init_cvtnum(&blocksize, &sectsize);
		offset = cvtnum(blocksize, sectsize, argv[optind]);
		if (offset < 0) {
			printf(_("non-numeric offset argument -- %s\n"),
				argv[optind]);
			exitcode = 1;
			return 0;
		}
		optind++;
		length = cvtnum(blocksize, sectsize, argv[optind]);
		if (length < 0) {
			printf(_("non-numeric length argument -- %s\n"),
				argv[optind]);
			exitcode = 1;
			return 0;
		}
	} else if (optind != argc) {
		exitcode = 1;
		return command_usage(&fadvise_cmd);
	}

	if (posix_fadvise(file->fd, offset, length, advise) < 0) {
		perror("fadvise");
		exitcode = 1;
		return 0;
	}
	return 0;
}

void
fadvise_init(void)
{
	fadvise_cmd.name = "fadvise";
	fadvise_cmd.cfunc = fadvise_f;
	fadvise_cmd.argmin = 0;
	fadvise_cmd.argmax = -1;
	fadvise_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
	fadvise_cmd.args = _("[-dnrsw] [off len]");
	fadvise_cmd.oneline = _("advisory commands for sections of a file");
	fadvise_cmd.help = fadvise_help;

	add_command(&fadvise_cmd);
}
Commit	Line	Data
959ef981	1	// SPDX-License-Identifier: GPL-2.0
48c46ee3	2	/*
da23017d NS	3	* Copyright (c) 2004-2005 Silicon Graphics, Inc.
da23017d NS	4	* All Rights Reserved.
48c46ee3 NS	5	*/
48c46ee3 NS	6
6b803e5a CH	7	#include "command.h"
6b803e5a CH	8	#include "input.h"
48c46ee3 NS	9	#include "init.h"
	10	#include "io.h"
	11
	12	static cmdinfo_t fadvise_cmd;
	13
48c46ee3 NS	14	static void
	15	fadvise_help(void)
	16	{
	17	printf(_(
	18	"\n"
	19	" advise the page cache about expected I/O patterns on the current file\n"
	20	"\n"
	21	" Modifies kernel page cache behaviour when operating on the current file.\n"
	22	" The range arguments are required by some advise commands ([*] below).\n"
	23	" With no arguments, the POSIX_FADV_NORMAL advice is implied.\n"
	24	" -d -- don't need these pages (POSIX_FADV_DONTNEED) [*]\n"
	25	" -n -- data will be accessed once (POSIX_FADV_NOREUSE) [*]\n"
	26	" -r -- expect random page references (POSIX_FADV_RANDOM)\n"
	27	" -s -- expect sequential page references (POSIX_FADV_SEQUENTIAL)\n"
	28	" -w -- will need these pages (POSIX_FADV_WILLNEED) [*]\n"
	29	" Notes: these interfaces are not supported in Linux kernels before 2.6.\n"
	30	" NORMAL sets the default readahead setting on the file.\n"
	31	" RANDOM sets the readahead setting on the file to zero.\n"
	32	" SEQUENTIAL sets double the default readahead setting on the file.\n"
	33	" WILLNEED and NOREUSE are equivalent, and force the maximum readahead.\n"
	34	"\n"));
	35	}
	36
	37	static int
	38	fadvise_f(
	39	int argc,
	40	char **argv)
	41	{
9e726740	42	off_t offset = 0, length = 0;
48c46ee3 NS	43	int c, range = 0, advise = POSIX_FADV_NORMAL;
	44
	45	while ((c = getopt(argc, argv, "dnrsw")) != EOF) {
	46	switch (c) {
	47	case 'd': /* Don't need these pages */
	48	advise = POSIX_FADV_DONTNEED;
	49	range = 1;
	50	break;
	51	case 'n': /* Data will be accessed once */
	52	advise = POSIX_FADV_NOREUSE;
	53	range = 1;
	54	break;
	55	case 'r': /* Expect random page references */
	56	advise = POSIX_FADV_RANDOM;
	57	range = 0;
	58	break;
	59	case 's': /* Expect sequential page references */
	60	advise = POSIX_FADV_SEQUENTIAL;
	61	range = 0;
	62	break;
	63	case 'w': /* Will need these pages */
	64	advise = POSIX_FADV_WILLNEED;
	65	range = 1;
	66	break;
	67	default:
9e1595e6	68	exitcode = 1;
48c46ee3 NS	69	return command_usage(&fadvise_cmd);
	70	}
	71	}
	72	if (range) {
2c2f6d79	73	size_t blocksize, sectsize;
48c46ee3	74
9e1595e6 DC	75	if (optind != argc - 2) {
9e1595e6 DC	76	exitcode = 1;
48c46ee3	77	return command_usage(&fadvise_cmd);
9e1595e6	78	}
48c46ee3 NS	79	init_cvtnum(&blocksize, &sectsize);
	80	offset = cvtnum(blocksize, sectsize, argv[optind]);
	81	if (offset < 0) {
	82	printf(_("non-numeric offset argument -- %s\n"),
	83	argv[optind]);
9e1595e6	84	exitcode = 1;
48c46ee3 NS	85	return 0;
	86	}
	87	optind++;
	88	length = cvtnum(blocksize, sectsize, argv[optind]);
	89	if (length < 0) {
	90	printf(_("non-numeric length argument -- %s\n"),
	91	argv[optind]);
9e1595e6	92	exitcode = 1;
48c46ee3 NS	93	return 0;
	94	}
	95	} else if (optind != argc) {
9e1595e6	96	exitcode = 1;
48c46ee3 NS	97	return command_usage(&fadvise_cmd);
	98	}
	99
f8edba5a	100	if (posix_fadvise(file->fd, offset, length, advise) < 0) {
48c46ee3	101	perror("fadvise");
9e1595e6	102	exitcode = 1;
48c46ee3 NS	103	return 0;
	104	}
	105	return 0;
	106	}
	107
	108	void
	109	fadvise_init(void)
	110	{
ad765595	111	fadvise_cmd.name = "fadvise";
48c46ee3 NS	112	fadvise_cmd.cfunc = fadvise_f;
	113	fadvise_cmd.argmin = 0;
	114	fadvise_cmd.argmax = -1;
	115	fadvise_cmd.flags = CMD_NOMAP_OK \| CMD_FOREIGN_OK;
	116	fadvise_cmd.args = _("[-dnrsw] [off len]");
	117	fadvise_cmd.oneline = _("advisory commands for sections of a file");
	118	fadvise_cmd.help = fadvise_help;
	119
	120	add_command(&fadvise_cmd);
	121	}