Re: [ntfs-3g-devel] Short reads when reading large files

[Szabolcs S. <sz...@nt...>]

Hi,

On Thu, 24 Jan 2008, Diomidis Spinellis wrote:

> When I read large files using ntfs-3g 1.1120 the read is truncated.  The 
> problem does not occur with shorter files.
> 
> Here are the file and read sizes for some cases:
> 
>   60,011,642,880 File size
>    4,177,068,032 Bytes read

Thank you for the bug report. This looks to be a FreeBSD specific LFS 
(large file support) issue. I can't reproduce it on Linux (1.2125-RC with 
fuse-lite):

  % dd of=file seek=60011642880 bs=1 < /dev/null
  % time dd if=file bs=1M >/dev/null
  57231+1 records in
  57231+1 records out
  60011642880 bytes (60 GB) copied, 296.022 seconds, 203 MB/s

I'm forwarding the email to our FreeBSD gurus ...

> Diomidis Spinellis - http://www.spinellis.gr

How small the world is! I just recently discovered and started to use your 
UMLGraph. I love it! I dreamt about such a declarative modelling tool for 
soooo long time. I also think your open source books are a must to read and 
honestly wish the advices would have been already all applied on the 
ntfs-3g source code for a long time ago! Thank you for them and sorry for 
being off-topic.

>   190,457,692,160 File size
>     1,479,131,136 Bytes read
> 
>        6,246,400 File size == Bytes read
>      639,733,760 File size == Bytes read
>    2,836,605,654 File size == Bytes read
> 
> I am reading the files under FreeBSD 8.0-CURRENT using dd with bs=1M. 
> Here is the corresponding debug output.
> 
> Version 1.1120
> Mounted /dev/da0s1 (Read-Write, label "Backup", NTFS 3.1)
> Cmdline options: debug
> Mount options: silent,allow_other,nonempty,relatime,fsname=/dev/da0s1
> unique: 0, opcode: INIT (26), nodeid: 0, insize: 56
> INIT: 7.8
> flags=0x00000000
> max_readahead=0x00000000
>     INIT: 7.8
>     flags=0x00000000
>     max_readahead=0x00000000
>     max_write=0x00020000
>     unique: 0, error: 0 (Unknown error: 0), outsize: 40
> [...]
> 
> LOOKUP /spiti-ad2c.dump
>     NODEID: 2
>     unique: 0, error: 0 (Unknown error: 0), outsize: 136
> unique: 0, opcode: OPEN (14), nodeid: 2, insize: 48
>     unique: 0, error: 0 (Unknown error: 0), outsize: 32
> OPEN[0] flags: 0x0 /spiti-ad2c.dump
> unique: 0, opcode: READ (15), nodeid: 2, insize: 64
> READ[0] 65536 bytes from 0
>     READ[0] 65536 bytes
>     unique: 0, error: 0 (Unknown error: 0), outsize: 65552
> unique: 0, opcode: READ (15), nodeid: 2, insize: 64
> READ[0] 65536 bytes from 65536
>     READ[0] 65536 bytes
>     unique: 0, error: 0 (Unknown error: 0), outsize: 65552
> [...]
> 
> READ[0] 65536 bytes from 1478950912
>     READ[0] 65536 bytes
>     unique: 0, error: 0 (Unknown error: 0), outsize: 65552
> unique: 0, opcode: READ (15), nodeid: 2, insize: 64
> READ[0] 65536 bytes from 1479016448
>     READ[0] 65536 bytes
>     unique: 0, error: 0 (Unknown error: 0), outsize: 65552
> unique: 0, opcode: READ (15), nodeid: 2, insize: 64
> READ[0] 49152 bytes from 1479081984
>     READ[0] 49152 bytes
>     unique: 0, error: 0 (Unknown error: 0), outsize: 49168
> unique: 0, opcode: RELEASE (18), nodeid: 2, insize: 64
> RELEASE+FLUSH[0] flags: 0x0
>     unique: 0, error: 0 (Unknown error: 0), outsize: 16
> 
> Diomidis Spinellis - http://www.spinellis.gr
> 
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2008.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> _______________________________________________
> ntfs-3g-devel mailing list
> ntf...@li...
> https://lists.sourceforge.net/lists/listinfo/ntfs-3g-devel
>