From 9d96af2e83a9519ac89ff0f8dae7f8478d33f581 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Wed, 13 Feb 2008 15:35:52 +0000 Subject: [PATCH] mkswap: fix help text to not lie about supported options. mkswap: use uint32, not int, to match kernel. mkswap: optimization: use pre-zeroed buffer --- include/usage.h | 61 ++++++++++++++++++++++++--------------------- util-linux/mkswap.c | 45 ++++++++++++++++++++++++++++----- 2 files changed, 72 insertions(+), 34 deletions(-) diff --git a/include/usage.h b/include/usage.h index 37cefeab1..df15dbb46 100644 --- a/include/usage.h +++ b/include/usage.h @@ -2335,14 +2335,17 @@ USE_FEATURE_BRCTL_FANCY("\n" \ "$ mknod -m 644 /tmp/pipe p\n" #define mkswap_trivial_usage \ - "[-c] [-v0|-v1] device [block-count]" + "DEVICE" #define mkswap_full_usage \ - "Prepare a disk partition to be used as swap partition" \ - "\n\nOptions:\n" \ - " -c Check for read-ability\n" \ - " -v0 Make version 0 swap [max 128 Megs]\n" \ - " -v1 Make version 1 swap [big!] (default for kernels > 2.1.117)\n" \ - " block-count Number of block to use (default is entire partition)" + "Prepare block device to be used as swap partition" +#if 0 + "[-c] [-v0|-v1] DEVICE [BLOCKS]" + "\n\nOptions:" + "\n -c Check for readability" + "\n -v0 Make swap version 0 (max 128M)" + "\n -v1 Make swap version 1 (default for kernels > 2.1.117)" + "\n BLOCKS Number of blocks to use (default is entire partition)" +#endif #define mktemp_trivial_usage \ "[-dt] [-p DIR] TEMPLATE" @@ -3312,34 +3315,36 @@ USE_FEATURE_RUN_PARTS_FANCY("\n -l Prints names of all matching files even when #define sort_trivial_usage \ "[-nru" \ - USE_FEATURE_SORT_BIG("gMcszbdfimSTokt] [-o outfile] [-k start[.offset][opts][,end[.offset][opts]] [-t char") \ + USE_FEATURE_SORT_BIG("gMcszbdfimSTokt] [-o FILE] [-k start[.offset][opts][,end[.offset][opts]] [-t CHAR") \ "] [FILE]..." #define sort_full_usage \ "Sort lines of text in the specified files" \ - "\n\nOptions:\n" \ + "\n\nOptions:" \ USE_FEATURE_SORT_BIG( \ - " -b Ignore leading blanks\n" \ - " -c Check whether input is sorted\n" \ - " -d Dictionary order (blank or alphanumeric only)\n" \ - " -f Ignore case\n" \ - " -g General numerical sort\n" \ - " -i Ignore unprintable characters\n" \ - " -k Sort key\n" \ - " -M Sort month\n") \ - " -n Sort numbers\n" \ + "\n -b Ignore leading blanks" \ + "\n -c Check whether input is sorted" \ + "\n -d Dictionary order (blank or alphanumeric only)" \ + "\n -f Ignore case" \ + "\n -g General numerical sort" \ + "\n -i Ignore unprintable characters" \ + "\n -k Sort key" \ + "\n -M Sort month" \ + ) \ + "\n -n Sort numbers" \ USE_FEATURE_SORT_BIG( \ - " -o Output to file\n" \ - " -k Sort by key\n" \ - " -t Use key separator other than whitespace\n") \ - " -r Reverse sort order\n" \ + "\n -o Output to file" \ + "\n -k Sort by key" \ + "\n -t CHAR Key separator" \ + ) \ + "\n -r Reverse sort order" \ USE_FEATURE_SORT_BIG( \ - " -s Stable (don't sort ties alphabetically)\n") \ - " -u Suppress duplicate lines" \ + "\n -s Stable (don't sort ties alphabetically)" \ + ) \ + "\n -u Suppress duplicate lines" \ USE_FEATURE_SORT_BIG( \ - "\n -z Input terminated by nulls, not newlines\n") \ - USE_FEATURE_SORT_BIG( \ - " -mST Ignored for GNU compatibility") \ - "" + "\n -z Lines are terminated by NUL, not newline" \ + "\n -mST Ignored for GNU compatibility") \ + #define sort_example_usage \ "$ echo -e \"e\\nf\\nb\\nd\\nc\\na\" | sort\n" \ "a\n" \ diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c index 31d577315..bf0d7b074 100644 --- a/util-linux/mkswap.c +++ b/util-linux/mkswap.c @@ -50,12 +50,47 @@ static void mkswap_selinux_setcontext(int fd, const char *path) #define mkswap_selinux_setcontext(fd, path) ((void)0) #endif +#if 0 /* from Linux 2.6.23 */ +/* + * Magic header for a swap area. The first part of the union is + * what the swap magic looks like for the old (limited to 128MB) + * swap area format, the second part of the union adds - in the + * old reserved area - some extra information. Note that the first + * kilobyte is reserved for boot loader or disk label stuff... + */ +union swap_header { + struct { + char reserved[PAGE_SIZE - 10]; + char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ + } magic; + struct { + char bootbits[1024]; /* Space for disklabel etc. */ + __u32 version; /* second kbyte, word 0 */ + __u32 last_page; /* 1 */ + __u32 nr_badpages; /* 2 */ + unsigned char sws_uuid[16]; /* 3,4,5,6 */ + unsigned char sws_volume[16]; /* 7,8,9,10 */ + __u32 padding[117]; /* 11..127 */ + __u32 badpages[1]; /* 128, total 129 32-bit words */ + } info; +}; +#endif + +#define NWORDS 129 +#define hdr ((uint32_t*)(&bb_common_bufsiz1)) + +struct BUG_bufsiz1_is_too_small { + char BUG_bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1]; +}; + +/* Stored without terminating NUL */ +static const char SWAPSPACE2[sizeof("SWAPSPACE2")-1] ALIGN1 = "SWAPSPACE2"; + int mkswap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int mkswap_main(int argc, char **argv) { int fd, pagesize; off_t len; - unsigned int hdr[129]; // No options supported. @@ -74,9 +109,7 @@ int mkswap_main(int argc, char **argv) len - pagesize); mkswap_selinux_setcontext(fd, argv[1]); - // Make a header. - - memset(hdr, 0, sizeof(hdr)); + // Make a header. hdr is zero-filled so far... hdr[0] = 1; hdr[1] = (len / pagesize) - 1; @@ -84,9 +117,9 @@ int mkswap_main(int argc, char **argv) // signature on disk (not in cache) during swapon. xlseek(fd, 1024, SEEK_SET); - xwrite(fd, hdr, sizeof(hdr)); + xwrite(fd, hdr, NWORDS * 4); xlseek(fd, pagesize - 10, SEEK_SET); - xwrite(fd, "SWAPSPACE2", 10); + xwrite(fd, SWAPSPACE2, 10); fsync(fd); if (ENABLE_FEATURE_CLEAN_UP) close(fd);