Jeremie Courreges-Anglas <[email protected]> writes:
> Landry Breuil <[email protected]> writes:
>
>> Hi,
>>
>> i know we don't really have an ntfs maintainer, and that nobody should
>> use ntfs, but interoperability...
>>
>> i have a 8Tb 'seagate backup plus hub' appearing as:
>>
>> uhub8 at uhub1 port 5 configuration 1 interface 0 "Seagate Backup+ Hub" rev
>> 2.10/48.85 addr 2
>> umass0 at uhub8 port 1 configuration 1 interface 0 "Seagate Backup+ Hub BK"
>> rev 2.10/1.00 addr 3
>> umass0: using SCSI over Bulk-Only
>> scsibus4 at umass0: 2 targets, initiator 0
>> sd2 at scsibus4 targ 1 lun 0: <Seagate, Backup+ Hub BK, D781> SCSI4 0/direct
>> fixed
>>
>> which just has a huge ntfs partition:
>>
>> # /dev/rsd2c:
>> type: SCSI
>> disk: SCSI disk
>> label: Backup+ Hub BK
>> duid: 0000000000000000
>> flags:
>> bytes/sector: 512
>> sectors/track: 63
>> tracks/cylinder: 255
>> sectors/cylinder: 16065
>> cylinders: 972801
>> total sectors: 15628053167
>> boundstart: 0
>> boundend: 15628053167
>> drivedata: 0
>>
>> 16 partitions:
>> # size offset fstype [fsize bsize cpg]
>> c: 15628053167 0 unused
>> i: 262144 34 unknown # /mnt/sd2
>> j: 15627788288 264192 MSDOS
>>
>> (with -pG)
>> total sectors: 15628053167 # total bytes: 7452.0G
>> c: 7452.0G 0 unused
>> i: 0.1G 34 unknown # /mnt/sd2
>> j: 7451.9G 264192 MSDOS
>>
>> Trying to mount it (dev/sd2j, of course) immediately panics the kernel
>> (hand-written):
>>
>> panic: out of space in kmem_map
>> panic
>> malloc
>> ntfs_calccfree
>> ntfs_mountfs
>> ntfs_mount
>> sys_mount
>> syscall
>>
>> I suppose pointing at
>> https://github.com/openbsd/src/blob/master/sys/ntfs/ntfs_vfsops.c#L567
>>
>> So, what can be done to 1) avoid the panic and 2) eventually find a way to
>> support those partitions sizes ?
>
> I guess that we should not allocate memory for the whole bitmap file,
> but instead split it in chunks.
>
> I have only tested with dummy ntfs volumes on vnd devices, but this
> fixes landry's panic and allows him to browse his NTFS filesystem.
>
> Concerns:
> - what would be a better chunk size than 1MB?
> - uint64_t vs off_t: add more tests
>
> Input welcome.
No opinion on that one?
> Index: ntfs/ntfs_vfsops.c
> ===================================================================
> RCS file: /d/cvs/src/sys/ntfs/ntfs_vfsops.c,v
> retrieving revision 1.55
> diff -u -p -r1.55 ntfs_vfsops.c
> --- ntfs/ntfs_vfsops.c 7 Sep 2016 17:30:12 -0000 1.55
> +++ ntfs/ntfs_vfsops.c 3 Mar 2017 17:52:18 -0000
> @@ -558,22 +558,35 @@ ntfs_calccfree(struct ntfsmount *ntmp, c
> u_int8_t *tmp;
> int j, error;
> cn_t cfree = 0;
> - size_t bmsize, i;
> + uint64_t bmsize, offset;
> + size_t chunksize, i;
>
> vp = ntmp->ntm_sysvn[NTFS_BITMAPINO];
>
> bmsize = VTOF(vp)->f_size;
>
> - tmp = malloc(bmsize, M_TEMP, M_WAITOK);
> + if (bmsize > 1024 * 1024)
> + chunksize = 1024 * 1024;
> + else
> + chunksize = bmsize;
> +
> + tmp = malloc(chunksize, M_TEMP, M_WAITOK);
> +
> + for (offset = 0; offset < bmsize; offset += chunksize) {
> + if (chunksize > bmsize - offset)
> + chunksize = bmsize - offset;
> +
> + error = ntfs_readattr(ntmp, VTONT(vp), NTFS_A_DATA, NULL,
> + offset, chunksize, tmp, NULL);
> + if (error)
> + goto out;
> +
> + for (i = 0; i < chunksize; i++)
> + for (j = 0; j < 8; j++)
> + if (~tmp[i] & (1 << j))
> + cfree++;
> + }
>
> - error = ntfs_readattr(ntmp, VTONT(vp), NTFS_A_DATA, NULL,
> - 0, bmsize, tmp, NULL);
> - if (error)
> - goto out;
> -
> - for(i=0;i<bmsize;i++)
> - for(j=0;j<8;j++)
> - if(~tmp[i] & (1 << j)) cfree++;
> *cfreep = cfree;
>
> out:
--
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
