diff options
Diffstat (limited to 'bin')
| -rw-r--r-- | bin/zhashfs.c | 154 |
1 files changed, 96 insertions, 58 deletions
diff --git a/bin/zhashfs.c b/bin/zhashfs.c index 12a0ffb..dd712ae 100644 --- a/bin/zhashfs.c +++ b/bin/zhashfs.c @@ -1,5 +1,8 @@ // Handle partitions #include <stdio.h> +#include <stdint.h> +#include <linux/fiemap.h> +#include <linux/fs.h> #define TFM_DESC #include <tomcrypt.h> @@ -13,6 +16,14 @@ static long zbufsize; static long zblocksize; static char *hashname; +static long eblocks = -1; + +/* + * A bitmap detailing which eblocks are used, and which are empty. + * (actually a char array, one byte per eblock, because I'm lazy) + */ +static unsigned char *eblocks_used; + #define PATTERN_SIZE 4096 #define DO(x) do { run_cmd((x), __LINE__, __FILE__, #x); } while (0); @@ -69,23 +80,95 @@ static int read_block(unsigned char *buf, FILE *infile, int is_last_block) return readlen; } +struct fiemap *read_fiemap(int fd) +{ + struct fiemap *fiemap; + int extents_size; + + if ((fiemap = (struct fiemap*)malloc(sizeof(struct fiemap))) == NULL) { + fprintf(stderr, "Out of memory allocating fiemap\n"); + return NULL; + } + memset(fiemap, 0, sizeof(struct fiemap)); + + fiemap->fm_start = 0; + fiemap->fm_length = ~0; + fiemap->fm_flags = 0; + fiemap->fm_extent_count = 0; + fiemap->fm_mapped_extents = 0; + + /* Find out how many extents there are */ + if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0) { + fprintf(stderr, "fiemap ioctl() failed\n"); + return NULL; + } + + /* Read in the extents */ + extents_size = sizeof(struct fiemap_extent) * (fiemap->fm_mapped_extents); + + /* Resize fiemap to allow us to read in the extents */ + if ((fiemap = (struct fiemap*)realloc(fiemap, sizeof(struct fiemap) + + extents_size)) == NULL) { + fprintf(stderr, "Out of memory allocating fiemap\n"); + return NULL; + } + + memset(fiemap->fm_extents, 0, extents_size); + fiemap->fm_extent_count = fiemap->fm_mapped_extents; + fiemap->fm_mapped_extents = 0; + + if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0) { + fprintf(stderr, "fiemap ioctl() failed\n"); + return NULL; + } + + return fiemap; +} + +/* Given a file extent, determine which eblocks in the output file need to + * represent that extent, and mark them as used in the eblocks_used map. */ +static void process_extent(struct fiemap_extent *ex) +{ + long i; + uint64_t last_byte = ex->fe_logical + ex->fe_length - 1; + long first_eblock = ex->fe_logical / zblocksize; + long last_eblock = last_byte / zblocksize; + + printf("Extent(%lld, %lld) occupies eblocks %d to %d\n", ex->fe_logical, ex->fe_length, first_eblock, last_eblock); + for (i = first_eblock; i <= last_eblock; i++) + eblocks_used[i] = 1; +} + +/* + * Use FIEMAP to determine the extents that make up a file. + * Allocate eblocks_used array based on length of file, and then mark + * the set of eblocks that contain data based on the extents. + */ +static void read_extents(FILE *infile) +{ + int i; + struct fiemap *fiemap = read_fiemap(fileno(infile)); + LTC_ARGCHK(fiemap != NULL); + + eblocks_used = malloc(eblocks); + LTC_ARGCHK(eblocks_used != 0); + memset(eblocks_used, 0, eblocks); + + for (i=0; i < fiemap->fm_mapped_extents; i++) + process_extent(&fiemap->fm_extents[i]); +} + int main(int argc, char **argv) { char *fname; unsigned char *buf; // EBLOCKSIZE FILE *infile; - long eblocks = -1; long i; off_t insize; int readlen; int skip; - unsigned char *pbuf; // fill pattern buffer - char pname[PATH_MAX]; // fill pattern file name - FILE *pfile; // fill pattern file - int patterned, n; - if (argc < 6) { fprintf(stderr, "%s: zblocksize hashname signed_file_name spec_file_name zdata_file_name [ #blocks ]\n", argv[0]); return EXIT_FAILURE; @@ -119,21 +202,6 @@ int main(int argc, char **argv) infile = fopen(argv[3], "rb"); LTC_ARGCHK(infile != NULL); - /* open and read an optional fill pattern file */ - pbuf = NULL; - strncpy(pname, argv[3], sizeof(pname) - 6); - strcat(pname, ".fill"); - pname[sizeof(pname) - 1] = 0; - - pfile = fopen(pname, "rb"); - if (pfile != NULL) { - pbuf = malloc(PATTERN_SIZE); - LTC_ARGCHK(pbuf != NULL); - n = fread(pbuf, 1, PATTERN_SIZE, pfile); - LTC_ARGCHK(n == PATTERN_SIZE); - fclose(pfile); - } - /* open output file */ outfile = fopen(argv[4], "wb"); LTC_ARGCHK(outfile != NULL); @@ -158,6 +226,8 @@ int main(int argc, char **argv) // LTC_ARGCHK((eblocks * zblocksize) == insize); } + read_extents(infile); + /* Remove possible path prefix */ fname = strrchr(argv[5], '/'); if (fname == NULL) @@ -171,48 +241,16 @@ int main(int argc, char **argv) fprintf(stdout, "Total blocks: %ld\n", eblocks); - fseek(infile, zblocksize, SEEK_SET); - /* make a hash of the file */ for (i=1; i < eblocks; i++) { + if (!eblocks_used[i]) + continue; + + fseeko(infile, (uint64_t) i * zblocksize, SEEK_SET); readlen = read_block(buf, infile, i == eblocks-1); LTC_ARGCHK(readlen == zblocksize); -#ifdef notdef - skip = 1; - for (p = (unsigned char *)buf; p < &buf[zblocksize]; p++) { - if (*p != 0xff) { - skip = 0; - break; - } - } -#else - skip = 0; -#endif - - if (pbuf) { - /* check if this zblock is fully patterned as unused, and if - any parts of the zblock are patterned then zero them, for ease - of compression */ - - patterned = 1; - for (n = 0; n < (zblocksize / PATTERN_SIZE); n++) { - if (memcmp(&buf[n*PATTERN_SIZE], pbuf, PATTERN_SIZE)) { - patterned = 0; - } else { - memset(&buf[n*PATTERN_SIZE], 0, PATTERN_SIZE); - } - } - - /* skip any block that is fully patterned, thus relying on the - fs-update card erase-blocks */ - - if (patterned) skip++; - } - - if (!skip) - write_block(i, buf); - + write_block(i, buf); fprintf(stdout, "\r%ld", i); fflush(stdout); } |