From: Ari Sundholm <[email protected]> This applet discards blocks on a given device. Tested with multiple 32-bit and 64-bit kernel versions and two different SSDs.
function old new delta blkdiscard_main - 300 +300 .rodata 154690 154795 +105 packed_usage 30275 30310 +35 applet_names 2499 2510 +11 applet_main 2904 2912 +8 applet_nameofs 726 728 +2 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 5/0 up/down: 461/0) Total: 461 bytes v2: Use a common error message format string when !S_ISBLK() to save space. Signed-off-by: Ari Sundholm <[email protected]> --- util-linux/blkdiscard.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 util-linux/blkdiscard.c diff --git a/util-linux/blkdiscard.c b/util-linux/blkdiscard.c new file mode 100644 index 0000000..2694c11 --- /dev/null +++ b/util-linux/blkdiscard.c @@ -0,0 +1,86 @@ +/* + * Mini blkdiscard implementation for busybox + * + * Copyright (C) 2015 by Ari Sundholm <[email protected]> and Tuxera Inc. + * + * Licensed under GPLv2 or later, see file LICENSE in this source tree. + */ + +//config:config BLKDISCARD +//config: bool "blkdiscard" +//config: default y +//config: help +//config: blkdiscard discards sectors on a given device. + +//kbuild:lib-$(CONFIG_BLKDISCARD) += blkdiscard.o +//applet:IF_BLKDISCARD(APPLET_NOFORK(blkdiscard, blkdiscard, BB_DIR_USR_BIN, BB_SUID_DROP, blkdiscard)) + +//usage:#define blkdiscard_trivial_usage +//usage: "[-o offset] [-l length] [-s] device" +//usage:#define blkdiscard_full_usage "\n\n" +//usage: "Discard sectors on the given device\n" +//usage: "\n -o offset Byte offset into device (default: 0)" +//usage: "\n -l length Number of bytes to discard (default: size of device)" +//usage: "\n -s Perform a secure discard" +//usage: +//usage:#define blkdiscard_example_usage +//usage: "$ blkdiscard -o 0 -l 1G /dev/sdb" + +#include "libbb.h" +#include <linux/fs.h> + +/* This is a NOFORK applet. Be very careful! */ + +int blkdiscard_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int blkdiscard_main(int argc UNUSED_PARAM, char **argv) +{ + unsigned opts; + uint64_t offset = 0; + char *offset_str; + uint64_t length; + char *length_str; + struct stat st; + int fd; + uint64_t range[2]; + + enum { + OPT_OFFSET = (1 << 0), + OPT_LENGTH = (1 << 1), + OPT_SECURE = (1 << 2), + }; + + opt_complementary = "=1"; + opts = getopt32(argv, "o:l:s", &offset_str, &length_str); + + xstat(argv[optind], &st); + if (!S_ISBLK(st.st_mode)) + bb_error_msg_and_die("%s: not a block device", argv[optind]); + + fd = xopen(argv[optind], O_RDWR|O_EXCL); + + if (opts & OPT_OFFSET) + offset = xatoull_sfx(offset_str, kMG_suffixes); + + if (opts & OPT_LENGTH) + length = xatoull_sfx(length_str, kMG_suffixes); + else { + ioctl_or_perror_and_die(fd, BLKGETSIZE64, &length, + "Failed to get device size"); + length -= offset; + } + + range[0] = offset; + range[1] = length; + ioctl_or_perror_and_die(fd, + (opts & OPT_SECURE) + ? BLKSECDISCARD + : BLKDISCARD, &range, + "%s failed", + (opts & OPT_SECURE) + ? "BLKSECDISCARD" + : "BLKDISCARD"); + + xclose(fd); + + return EXIT_SUCCESS; +} -- 1.9.1 _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
