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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2010-02-01 23:48:27 +0100 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2010-02-01 23:48:27 +0100 |
| commit | 40e7d25aca1abbe080e00e2bed64b444a5ec7858 (patch) | |
| tree | 05cda08f66542aeb94d1ebb906a0f04b04a41d62 /libbb/get_volsize.c | |
| parent | 4875e7148b0512ee3c255526a484503da984935a (diff) | |
| download | busybox-w32-40e7d25aca1abbe080e00e2bed64b444a5ec7858.tar.gz busybox-w32-40e7d25aca1abbe080e00e2bed64b444a5ec7858.tar.bz2 busybox-w32-40e7d25aca1abbe080e00e2bed64b444a5ec7858.zip | |
mkXXXX: unify [KBYTES] parameter handling (added it to mkswap)
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'libbb/get_volsize.c')
| -rw-r--r-- | libbb/get_volsize.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/libbb/get_volsize.c b/libbb/get_volsize.c new file mode 100644 index 000000000..5b0270968 --- /dev/null +++ b/libbb/get_volsize.c | |||
| @@ -0,0 +1,48 @@ | |||
| 1 | /* vi: set sw=4 ts=4: */ | ||
| 2 | /* | ||
| 3 | * Utility routines. | ||
| 4 | * | ||
| 5 | * Copyright (C) 2010 Denys Vlasenko | ||
| 6 | * | ||
| 7 | * Licensed under GPLv2, see file LICENSE in this tarball for details. | ||
| 8 | */ | ||
| 9 | #include "libbb.h" | ||
| 10 | |||
| 11 | uoff_t FAST_FUNC get_volume_size_in_bytes(int fd, | ||
| 12 | const char *override, | ||
| 13 | unsigned override_units, | ||
| 14 | int extend) | ||
| 15 | { | ||
| 16 | uoff_t result; | ||
| 17 | |||
| 18 | if (override) { | ||
| 19 | result = XATOOFF(override); | ||
| 20 | if (result >= (uoff_t)(MAXINT(off_t)) / override_units) | ||
| 21 | bb_error_msg_and_die("image size is too big"); | ||
| 22 | result *= override_units; | ||
| 23 | /* seek past end fails on block devices but works on files */ | ||
| 24 | if (lseek(fd, result - 1, SEEK_SET) != (off_t)-1) { | ||
| 25 | if (extend) | ||
| 26 | xwrite(fd, "", 1); /* file grows if needed */ | ||
| 27 | } | ||
| 28 | //else { | ||
| 29 | // bb_error_msg("warning, block device is smaller"); | ||
| 30 | //} | ||
| 31 | } else { | ||
| 32 | /* more portable than BLKGETSIZE[64] */ | ||
| 33 | result = xlseek(fd, 0, SEEK_END); | ||
| 34 | } | ||
| 35 | |||
| 36 | xlseek(fd, 0, SEEK_SET); | ||
| 37 | |||
| 38 | /* Prevent things like this: | ||
| 39 | * $ dd if=/dev/zero of=foo count=1 bs=1024 | ||
| 40 | * $ mkswap foo | ||
| 41 | * Setting up swapspace version 1, size = 18446744073709548544 bytes | ||
| 42 | * | ||
| 43 | * Picked 16k arbitrarily: */ | ||
| 44 | if (result < 16*1024) | ||
| 45 | bb_error_msg_and_die("image is too small"); | ||
| 46 | |||
| 47 | return result; | ||
| 48 | } | ||