> ChenMin wrote: >> THe model of USB disk is "SandDiak CRUZER SDCZ6-016G 16GB", and there >> is one signal partition on it. >> >> GNU Parted 2.3 >> Using /dev/sde >> Welcome to GNU Parted! Type 'help' to view a list of commands. >> (parted) p >> Model: SanDisk Cruzer (scsi) >> Disk /dev/sde: 16.0GB >> Sector size (logical/physical): 512B/512B >> Partition Table: msdos >> Number Start End Size Type File system Flags >> (parted) >> >> >> GNU Parted 1.8.8 >> Using /dev/sde >> Welcome to GNU Parted! Type 'help' to view a list of commands. >> (parted) p >> Model: SanDisk Cruzer (scsi) >> Disk /dev/sde: 16.0GB >> Sector size (logical/physical): 512B/512B >> Partition Table: loop >> Number Start End Size File system Flags >> 1 0.00B 16.0GB 16.0GB fat32 >> (parted) > > Thanks for reporting that regression. > I've reproduced it like this: > > $ dd if=/dev/null of=F bs=1 seek=40M > $ mkfs.vfat -F 16 F > $ parted -s F print > Model: (file) > Disk /f12/home/meyering/w/co/parted/parted/F: 41.9MB > Sector size (logical/physical): 512B/512B > Partition Table: msdos > > Number Start End Size Type File system Flags > > Note there is no partition listed above. > Repeating the final command using parted built with > the patch below, it works as expected: > > $ parted/parted -s F print|grep fat > 1 0.00B 41.9MB 41.9MB fat16 > > I'll use something like the following patch, > once I've written a test: > > From 7167b646e82dd29372a0239bec0bc9053bae678b Mon Sep 17 00:00:00 2001 > From: Jim Meyering > Date: Wed, 14 Jul 2010 19:16:14 -0500 > Subject: [PATCH] libparted: avoid regression when processing a whole-disk FAT > partition > > Without this change, we would improperly classify a whole-disk partition > containing a FAT file system as a DOS partition table with no partitions. > Introduced by commit d732a2b7 on 2008-05-28. > * libparted/labels/dos.c (maybe_FAT): New function. > (msdos_probe): Use it. > Reported by ChenMin in > http://thread.gmane.org/gmane.comp.gnu.parted.bugs/10115 > --- > libparted/labels/dos.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 75 insertions(+), 0 deletions(-) > > diff --git a/libparted/labels/dos.c b/libparted/labels/dos.c > index f66ca47..d9e7d4a 100644 > --- a/libparted/labels/dos.c > +++ b/libparted/labels/dos.c > @@ -164,6 +164,73 @@ typedef struct { > > static PedDiskType msdos_disk_type; > > +#if 0 > +From http://www.win.tue.nl/~aeb/linux/fs/fat/fat-1.html > + > +The 2-byte numbers are stored little endian (low order byte first). > + > +Here the FAT12 version, that is also the common part of the FAT12, FAT16 and > FAT32 boot sectors. See further below. > + > +Bytes Content > +0-2 Jump to bootstrap (E.g. eb 3c 90; on i86: JMP 003E NOP. > + One finds either eb xx 90, or e9 xx xx. > + The position of the bootstrap varies.) > +3-10 OEM name/version (E.g. "IBM 3.3", "IBM 20.0", "MSDOS5.0", "MSWIN4.0". > + Various format utilities leave their own name, like "CH-FOR18". > + Sometimes just garbage. Microsoft recommends "MSWIN4.1".) > + /* BIOS Parameter Block starts here */ > +11-12 Number of bytes per sector (512) > + Must be one of 512, 1024, 2048, 4096. > +13 Number of sectors per cluster (1) > + Must be one of 1, 2, 4, 8, 16, 32, 64, 128. > + A cluster should have at most 32768 bytes. In rare cases 65536 is OK. > +14-15 Number of reserved sectors (1) > + FAT12 and FAT16 use 1. FAT32 uses 32. > +16 Number of FAT copies (2) > +17-18 Number of root directory entries (224) > + 0 for FAT32. 512 is recommended for FAT16. > +19-20 Total number of sectors in the filesystem (2880) > + (in case the partition is not FAT32 and smaller than 32 MB) > +21 Media descriptor type (f0: 1.4 MB floppy, f8: hard disk; see below) > +22-23 Number of sectors per FAT (9) > + 0 for FAT32. > +24-25 Number of sectors per track (12) > +26-27 Number of heads (2, for a double-sided diskette) > +28-29 Number of hidden sectors (0) > + Hidden sectors are sectors preceding the partition. > + /* BIOS Parameter Block ends here */ > +30-509 Bootstrap > +510-511 Signature 55 aa > +#endif > + > +/* There is a significant risk of misclassifying (as msdos) > + a disk that is composed solely of a single FAT partition. > + Return false if sector S could not be a valid FAT boot sector. > + Otherwise, return true. */ > +static bool > +maybe_FAT (unsigned char const *s) > +{ > + if (! (s[0] == 0xeb || s[0] == 0xe9)) > + return false; > + > + unsigned int sector_size = PED_LE16_TO_CPU (*(uint16_t *) (s + 11)); > + switch (sector_size) > + { > + case 512: > + case 1024: > + case 2048: > + case 4096: > + break; > + default: > + return false; > + } > + > + if (! (s[21] == 0xf0 || s[21] == 0xf8)) > + return false; > + > + return true; > +} > + > static int > msdos_probe (const PedDevice *dev) > { > @@ -191,12 +258,20 @@ msdos_probe (const PedDevice *dev) > * and ensure that each partition has a boot indicator that is > * either 0 or 0x80. > */ > + unsigned int n_active = 0; > for (i = 0; i < DOS_N_PRI_PARTITIONS; i++) { > + if (part_table->partitions[i].boot_ind == 0x80) > + ++n_active; > if (part_table->partitions[i].boot_ind != 0 > && part_table->partitions[i].boot_ind != 0x80) > goto probe_fail; > } > > + /* If there are no active partitions and this is probably > + a FAT file system, do not classify it as msdos. */ > + if (n_active == 0 && maybe_FAT (label)) > + goto probe_fail; > + > /* If this is a GPT disk, fail here */ > for (i = 0; i < DOS_N_PRI_PARTITIONS; i++) { > if (part_table->partitions[i].type == PARTITION_GPT) > -- > 1.7.1.460.gf3c4c
Hi Jim, Thanks very much for your work. BRs! _________________________________________________________________ 想知道明天天气如何？必应告诉你！ http://cn.bing.com/search?q=%E5%A4%A9%E6%B0%94%E9%A2%84%E6%8A%A5&form=MICHJ2 _______________________________________________ bug-parted mailing list bug-parted@gnu.org http://lists.gnu.org/mailman/listinfo/bug-parted
