Applied, thanks! Please try and yell at me if something's not right.
On Tue, Dec 1, 2015 at 2:55 PM, Ari Sundholm <[email protected]> wrote: > 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. > v3: Make the applet configuration option default to n and add a comment > regarding two not strictly necessary variables which help readability. > > 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..0d28da2 > --- /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 n > +//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; > + char *offset_str; > + char *length_str; > + uint64_t offset = 0; /* Leaving these two variables out does not */ > + uint64_t length; /* shrink code size and hampers readability. */ > + uint64_t range[2]; > + struct stat st; > + int fd; > + > + 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 _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
