fdisk: make 'b' command optionally adjust C/H/S; "fdisk IMAGE_FILE" sets cylinders
authorDenys Vlasenko <vda.linux@googlemail.com>
Tue, 6 Apr 2010 00:32:26 +0000 (02:32 +0200)
committerDenys Vlasenko <vda.linux@googlemail.com>
Tue, 6 Apr 2010 00:32:26 +0000 (02:32 +0200)
function                                             old     new   delta
set_hsc_start_end                                      -     189    +189
get_boot                                            1644    1713     +69
fdisk_main                                          2620    2652     +32
get_partition_start_from_dev_start                     -      15     +15
get_partition_start                                   15       -     -15
set_partition                                        286     120    -166
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 2/1 up/down: 305/-181)          Total: 124 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
util-linux/fdisk.c

index cb15bd26738d16e8220d018c0faf637e59faff6e..06fb7f9b0cc3d977d3ecd7aea3eb43f919fc54b6 100644 (file)
@@ -185,7 +185,7 @@ static sector_t get_nr_sects(const struct partition *p);
 struct pte {
        struct partition *part_table;   /* points into sectorbuffer */
        struct partition *ext_pointer;  /* points into sectorbuffer */
-       sector_t offset;                /* disk sector number */
+       sector_t offset_from_dev_start; /* disk sector number */
        char *sectorbuffer;             /* disk sector contents */
 #if ENABLE_FEATURE_FDISK_WRITABLE
        char changed;                   /* boolean */
@@ -407,8 +407,14 @@ static sector_t bb_BLKGETSIZE_sectors(int fd)
                return v64;
        }
        /* Needs temp of type long */
-       if (ioctl(fd, BLKGETSIZE, &longsectors))
+       if (ioctl(fd, BLKGETSIZE, &longsectors)) {
+               /* Perhaps this is a disk image */
+               off_t sz = lseek(fd, 0, SEEK_END);
                longsectors = 0;
+               if (sz > 0)
+                       longsectors = (uoff_t)sz / sector_size;
+               lseek(fd, 0, SEEK_SET);
+       }
        if (sizeof(long) > sizeof(sector_t)
         && longsectors != (sector_t)longsectors
        ) {
@@ -435,16 +441,6 @@ static sector_t bb_BLKGETSIZE_sectors(int fd)
 #define hsc2sector(h,s,c) \
        (sector(s) - 1 + sectors * ((h) + heads * cylinder(s,c)))
 
-#define set_hsc(h,s,c,sector) \
-       do { \
-               s = sector % g_sectors + 1;  \
-               sector /= g_sectors;         \
-               h = sector % g_heads;        \
-               sector /= g_heads;           \
-               c = sector & 0xff;           \
-               s |= (sector >> 2) & 0xc0;   \
-       } while (0)
-
 static void
 close_dev_fd(void)
 {
@@ -603,7 +599,7 @@ read_hex(const char *const *sys)
        unsigned long v;
        while (1) {
                read_nonempty("Hex code (type L to list codes): ");
-               if (*line_ptr == 'l' || *line_ptr == 'L') {
+               if ((line_ptr[0] | 0x20) == 'l') {
                        list_types(sys);
                        continue;
                }
@@ -759,7 +755,7 @@ set_nr_sects(struct partition *p, unsigned nr_sects)
 static void
 read_pte(struct pte *pe, sector_t offset)
 {
-       pe->offset = offset;
+       pe->offset_from_dev_start = offset;
        pe->sectorbuffer = xzalloc(sector_size);
        seek_sector(offset);
        /* xread would make us abort - bad for fdisk -l */
@@ -772,9 +768,9 @@ read_pte(struct pte *pe, sector_t offset)
 }
 
 static sector_t
-get_partition_start(const struct pte *pe)
+get_partition_start_from_dev_start(const struct pte *pe)
 {
-       return pe->offset + get_start_sect(pe->part_table);
+       return pe->offset_from_dev_start + get_start_sect(pe->part_table);
 }
 
 #if ENABLE_FEATURE_FDISK_WRITABLE
@@ -1012,6 +1008,27 @@ list_types(const char *const *sys)
        bb_putchar('\n');
 }
 
+#define set_hsc(h, s, c, sector) do \
+{ \
+       s = sector % g_sectors + 1;  \
+       sector /= g_sectors;         \
+       h = sector % g_heads;        \
+       sector /= g_heads;           \
+       c = sector & 0xff;           \
+       s |= (sector >> 2) & 0xc0;   \
+} while (0)
+
+static void set_hsc_start_end(struct partition *p, sector_t start, sector_t stop)
+{
+       if (dos_compatible_flag && (start / (g_sectors * g_heads) > 1023))
+               start = g_heads * g_sectors * 1024 - 1;
+       set_hsc(p->head, p->sector, p->cyl, start);
+
+       if (dos_compatible_flag && (stop / (g_sectors * g_heads) > 1023))
+               stop = g_heads * g_sectors * 1024 - 1;
+       set_hsc(p->end_head, p->end_sector, p->end_cyl, stop);
+}
+
 static void
 set_partition(int i, int doext, sector_t start, sector_t stop, int sysid)
 {
@@ -1023,18 +1040,13 @@ set_partition(int i, int doext, sector_t start, sector_t stop, int sysid)
                offset = extended_offset;
        } else {
                p = ptes[i].part_table;
-               offset = ptes[i].offset;
+               offset = ptes[i].offset_from_dev_start;
        }
        p->boot_ind = 0;
        p->sys_ind = sysid;
        set_start_sect(p, start - offset);
        set_nr_sects(p, stop - start + 1);
-       if (dos_compatible_flag && (start / (g_sectors * g_heads) > 1023))
-               start = g_heads * g_sectors * 1024 - 1;
-       set_hsc(p->head, p->sector, p->cyl, start);
-       if (dos_compatible_flag && (stop / (g_sectors * g_heads) > 1023))
-               stop = g_heads * g_sectors * 1024 - 1;
-       set_hsc(p->end_head, p->end_sector, p->end_cyl, stop);
+       set_hsc_start_end(p, start, stop);
        ptes[i].changed = 1;
 }
 #endif
@@ -1316,7 +1328,7 @@ static int get_boot(void)
                struct pte *pe = &ptes[i];
                pe->part_table = pt_offset(MBRbuffer, i);
                pe->ext_pointer = NULL;
-               pe->offset = 0;
+               pe->offset_from_dev_start = 0;
                pe->sectorbuffer = MBRbuffer;
 #if ENABLE_FEATURE_FDISK_WRITABLE
                pe->changed = (what == CREATE_EMPTY_DOS);
@@ -1700,9 +1712,9 @@ delete_partition(int i)
 
                        if (pe->part_table) /* prevent SEGFAULT */
                                set_start_sect(pe->part_table,
-                                               get_partition_start(pe) -
+                                               get_partition_start_from_dev_start(pe) -
                                                extended_offset);
-                       pe->offset = extended_offset;
+                       pe->offset_from_dev_start = extended_offset;
                        pe->changed = 1;
                }
 
@@ -1914,7 +1926,7 @@ wrong_p_order(int *prev)
                pe = &ptes[i];
                p = pe->part_table;
                if (p->sys_ind) {
-                       p_start_pos = get_partition_start(pe);
+                       p_start_pos = get_partition_start_from_dev_start(pe);
 
                        if (last_p_start_pos > p_start_pos) {
                                if (prev)
@@ -1953,11 +1965,11 @@ fix_chain_of_logicals(void)
        /* (Its sector is the global extended_offset.) */
  stage1:
        for (j = 5; j < g_partitions - 1; j++) {
-               oj = ptes[j].offset;
-               ojj = ptes[j+1].offset;
+               oj = ptes[j].offset_from_dev_start;
+               ojj = ptes[j+1].offset_from_dev_start;
                if (oj > ojj) {
-                       ptes[j].offset = ojj;
-                       ptes[j+1].offset = oj;
+                       ptes[j].offset_from_dev_start = ojj;
+                       ptes[j+1].offset_from_dev_start = oj;
                        pj = ptes[j].part_table;
                        set_start_sect(pj, get_start_sect(pj)+oj-ojj);
                        pjj = ptes[j+1].part_table;
@@ -1977,8 +1989,8 @@ fix_chain_of_logicals(void)
                pjj = ptes[j+1].part_table;
                sj = get_start_sect(pj);
                sjj = get_start_sect(pjj);
-               oj = ptes[j].offset;
-               ojj = ptes[j+1].offset;
+               oj = ptes[j].offset_from_dev_start;
+               ojj = ptes[j+1].offset_from_dev_start;
                if (oj+sj > ojj+sjj) {
                        tmp = *pj;
                        *pj = *pjj;
@@ -2095,8 +2107,8 @@ list_table(int xtra)
                        partname(disk_device, i+1, w+2),
                        !p->boot_ind ? ' ' : p->boot_ind == ACTIVE_FLAG /* boot flag */
                                ? '*' : '?',
-                       cround(get_partition_start(pe)),           /* start */
-                       cround(get_partition_start(pe) + psects    /* end */
+                       cround(get_partition_start_from_dev_start(pe)),           /* start */
+                       cround(get_partition_start_from_dev_start(pe) + psects    /* end */
                                - (psects ? 1 : 0)),
                        pblocks, podd ? '+' : ' ', /* odd flag on end */
                        p->sys_ind,                                     /* type id */
@@ -2158,7 +2170,7 @@ fill_bounds(sector_t *first, sector_t *last)
                        first[i] = 0xffffffff;
                        last[i] = 0;
                } else {
-                       first[i] = get_partition_start(pe);
+                       first[i] = get_partition_start_from_dev_start(pe);
                        last[i] = first[i] + get_nr_sects(p) - 1;
                }
        }
@@ -2215,7 +2227,7 @@ verify(void)
                p = pe->part_table;
                if (p->sys_ind && !IS_EXTENDED(p->sys_ind)) {
                        check_consistency(p, i);
-                       if (get_partition_start(pe) < first[i])
+                       if (get_partition_start_from_dev_start(pe) < first[i])
                                printf("Warning: bad start-of-data in "
                                        "partition %u\n", i + 1);
                        check(i + 1, p->end_head, p->end_sector, p->end_cyl,
@@ -2305,7 +2317,7 @@ add_partition(int n, int sys)
                for (i = 0; i < g_partitions; i++) {
                        int lastplusoff;
 
-                       if (start == ptes[i].offset)
+                       if (start == ptes[i].offset_from_dev_start)
                                start += sector_offset;
                        lastplusoff = last[i] + ((n < 4) ? 0 : sector_offset);
                        if (start >= first[i] && start <= lastplusoff)
@@ -2322,8 +2334,7 @@ add_partition(int n, int sys)
                        sector_t saved_start;
 
                        saved_start = start;
-                       start = read_int(cround(saved_start), cround(saved_start), cround(limit),
-                                        0, mesg);
+                       start = read_int(cround(saved_start), cround(saved_start), cround(limit), 0, mesg);
                        if (display_in_cyl_units) {
                                start = (start - 1) * units_per_sector;
                                if (start < saved_start)
@@ -2335,9 +2346,9 @@ add_partition(int n, int sys)
        if (n > 4) {                    /* NOT for fifth partition */
                struct pte *pe = &ptes[n];
 
-               pe->offset = start - sector_offset;
-               if (pe->offset == extended_offset) { /* must be corrected */
-                       pe->offset++;
+               pe->offset_from_dev_start = start - sector_offset;
+               if (pe->offset_from_dev_start == extended_offset) { /* must be corrected */
+                       pe->offset_from_dev_start++;
                        if (sector_offset == 1)
                                start++;
                }
@@ -2346,8 +2357,8 @@ add_partition(int n, int sys)
        for (i = 0; i < g_partitions; i++) {
                struct pte *pe = &ptes[i];
 
-               if (start < pe->offset && limit >= pe->offset)
-                       limit = pe->offset - 1;
+               if (start < pe->offset_from_dev_start && limit >= pe->offset_from_dev_start)
+                       limit = pe->offset_from_dev_start - 1;
                if (start < first[i] && limit >= first[i])
                        limit = first[i] - 1;
        }
@@ -2363,8 +2374,7 @@ add_partition(int n, int sys)
                snprintf(mesg, sizeof(mesg),
                         "Last %s or +size or +sizeM or +sizeK",
                         str_units(SINGULAR));
-               stop = read_int(cround(start), cround(limit), cround(limit),
-                               cround(start), mesg);
+               stop = read_int(cround(start), cround(limit), cround(limit), cround(start), mesg);
                if (display_in_cyl_units) {
                        stop = stop * units_per_sector - 1;
                        if (stop >limit)
@@ -2374,7 +2384,7 @@ add_partition(int n, int sys)
 
        set_partition(n, 0, start, stop, sys);
        if (n > 4)
-               set_partition(n - 1, 1, ptes[n].offset, stop, EXTENDED);
+               set_partition(n - 1, 1, ptes[n].offset_from_dev_start, stop, EXTENDED);
 
        if (IS_EXTENDED(sys)) {
                struct pte *pe4 = &ptes[4];
@@ -2382,7 +2392,7 @@ add_partition(int n, int sys)
 
                ext_index = n;
                pen->ext_pointer = p;
-               pe4->offset = extended_offset = start;
+               pe4->offset_from_dev_start = extended_offset = start;
                pe4->sectorbuffer = xzalloc(sector_size);
                pe4->part_table = pt_offset(pe4->sectorbuffer, 0);
                pe4->ext_pointer = pe4->part_table + 1;
@@ -2400,7 +2410,7 @@ add_logical(void)
                pe->sectorbuffer = xzalloc(sector_size);
                pe->part_table = pt_offset(pe->sectorbuffer, 0);
                pe->ext_pointer = pe->part_table + 1;
-               pe->offset = 0;
+               pe->offset_from_dev_start = 0;
                pe->changed = 1;
                g_partitions++;
        }
@@ -2454,7 +2464,7 @@ new_partition(void)
                        "l   logical (5 or over)" : "e   extended"));
                while (1) {
                        c = read_nonempty(line);
-                       if (c == 'p' || c == 'P') {
+                       if ((c | 0x20) == 'p') {
                                i = get_nonexisting_partition(0, 4);
                                if (i >= 0)
                                        add_partition(i, LINUX_NATIVE);
@@ -2490,7 +2500,7 @@ write_table(void)
 
                        if (pe->changed) {
                                write_part_table_flag(pe->sectorbuffer);
-                               write_sector(pe->offset, pe->sectorbuffer);
+                               write_sector(pe->offset_from_dev_start, pe->sectorbuffer);
                        }
                }
        }
@@ -2579,22 +2589,26 @@ move_begin(unsigned i)
 {
        struct pte *pe = &ptes[i];
        struct partition *p = pe->part_table;
-       sector_t new, first;
+       sector_t new, first, nr_sects;
 
        if (warn_geometry())
                return;
-       if (!p->sys_ind || !get_nr_sects(p) || IS_EXTENDED(p->sys_ind)) {
+       nr_sects = get_nr_sects(p);
+       if (!p->sys_ind || !nr_sects || IS_EXTENDED(p->sys_ind)) {
                printf("Partition %u has no data area\n", i + 1);
                return;
        }
-       first = get_partition_start(pe);
-       new = read_int(first, first, first + get_nr_sects(p) - 1, first,
-                          "New beginning of data") - pe->offset;
-
-       if (new != get_nr_sects(p)) {
-               first = get_nr_sects(p) + get_start_sect(p) - new;
-               set_nr_sects(p, first);
-               set_start_sect(p, new);
+       first = get_partition_start_from_dev_start(pe);
+       /* == pe->offset_from_dev_start + get_start_sect(p) */
+       new = read_int(0 /*was:first*/, first, first + nr_sects - 1, first, "New beginning of data");
+       if (new != first) {
+               sector_t new_relative = new - pe->offset_from_dev_start;
+               nr_sects += (get_start_sect(p) - new_relative);
+               set_start_sect(p, new_relative);
+               set_nr_sects(p, nr_sects);
+               read_nonempty("Recalculate C/H/S values? (Y/N): ");
+               if ((line_ptr[0] | 0x20) == 'y')
+                       set_hsc_start_end(p, new, new + nr_sects - 1);
                pe->changed = 1;
        }
 }
@@ -2606,7 +2620,7 @@ xselect(void)
 
        while (1) {
                bb_putchar('\n');
-               c = tolower(read_nonempty("Expert command (m for help): "));
+               c = 0x20 | read_nonempty("Expert command (m for help): ");
                switch (c) {
                case 'a':
                        if (LABEL_IS_SUN)
@@ -2646,8 +2660,7 @@ xselect(void)
 #endif
                        break;
                case 'h':
-                       user_heads = g_heads = read_int(1, g_heads, 256, 0,
-                                       "Number of heads");
+                       user_heads = g_heads = read_int(1, g_heads, 256, 0, "Number of heads");
                        update_units();
                        break;
                case 'i':
@@ -2672,8 +2685,7 @@ xselect(void)
                case 'r':
                        return;
                case 's':
-                       user_sectors = g_sectors = read_int(1, g_sectors, 63, 0,
-                                          "Number of sectors");
+                       user_sectors = g_sectors = read_int(1, g_sectors, 63, 0, "Number of sectors");
                        if (dos_compatible_flag) {
                                sector_offset = g_sectors;
                                printf("Warning: setting sector offset for DOS "
@@ -2834,14 +2846,17 @@ int fdisk_main(int argc UNUSED_PARAM, char **argv)
        opt = getopt32(argv, "b:C:H:lS:u" IF_FEATURE_FDISK_BLKSIZE("s"),
                                &sector_size, &user_cylinders, &user_heads, &user_sectors);
        argv += optind;
-       if (opt & OPT_b) { // -b
+       if (opt & OPT_b) {
                /* Ugly: this sector size is really per device,
-                  so cannot be combined with multiple disks,
-                  and the same goes for the C/H/S options.
-               */
-               if (sector_size != 512 && sector_size != 1024
-                && sector_size != 2048)
+                * so cannot be combined with multiple disks,
+                * and the same goes for the C/H/S options.
+                */
+               if (sector_size < 512
+                || sector_size > 0x10000
+                || (sector_size & (sector_size-1)) /* not power of 2 */
+               ) {
                        bb_show_usage();
+               }
                sector_offset = 2;
                user_set_sector_size = 1;
        }
@@ -2912,7 +2927,7 @@ int fdisk_main(int argc UNUSED_PARAM, char **argv)
        while (1) {
                int c;
                bb_putchar('\n');
-               c = tolower(read_nonempty("Command (m for help): "));
+               c = 0x20 | read_nonempty("Command (m for help): ");
                switch (c) {
                case 'a':
                        if (LABEL_IS_DOS)