diff options
Diffstat (limited to 'sbin/fsck_msdosfs/check.c')
| -rw-r--r-- | sbin/fsck_msdosfs/check.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/sbin/fsck_msdosfs/check.c b/sbin/fsck_msdosfs/check.c index 28b1588..72e5b0a 100644 --- a/sbin/fsck_msdosfs/check.c +++ b/sbin/fsck_msdosfs/check.c @@ -84,6 +84,13 @@ checkfilesys(const char *fname) return 8; } + if (checkdirty(dosfs, &boot) && !force) { + if (preen) printf("%s: ", fname); + printf("FILESYSTEM CLEAN; SKIPPING CHECKS\n"); + ret = 0; + goto out; + } + if (!preen) { if (boot.ValidFat < 0) printf("** Phase 1 - Read and Compare FATs\n"); @@ -191,3 +198,48 @@ checkfilesys(const char *fname) return ret; } + +int checkdirty(int fs, struct bootblock *boot) +{ + off_t off; + u_char *buffer; + int ret = 0; + + if (boot->ClustMask == CLUST12_MASK) + return 0; + + off = boot->ResSectors; + off *= boot->BytesPerSec; + + buffer = malloc(boot->BytesPerSec); + if (buffer == NULL) { + perror("No space for FAT"); + return 1; + } + + if (lseek(fs, off, SEEK_SET) != off) { + perror("Unable to read FAT"); + goto err; + } + + if (read(fs, buffer, boot->BytesPerSec) + != boot->BytesPerSec) { + perror("Unable to read FAT"); + goto err; + } + + if (buffer[0] == boot->Media && buffer[1] == 0xff + && buffer[2] == 0xff + && ((boot->ClustMask == CLUST16_MASK && buffer[3] == 0x7f) + || (boot->ClustMask == CLUST32_MASK + && buffer[3] == 0x0f && buffer[4] == 0xff + && buffer[5] == 0xff && buffer[6] == 0xff + && buffer[7] == 0x07))) + ret = 0; + else + ret = 1; + +err: + free(buffer); + return ret; +} |
