10 ms·

Samsung's exFAT Linux driver officially released as GPL

172 points by 0x0 13y ago

samspenc 13y ago
I remember there was heated discussion about whether the initial "release" was legit or not. Was that ever resolved?
- 0x0 13y ago
  The first version seemed to be a leak with a very unclear licensing situation. This here is the resolution :)
  - zokier 13y ago
    The licensing situation of the leak was quite clear; it was proprietary code without any doubt.
regularfry 13y ago
What's the patent status of exFAT?
- drdaeman 13y ago
  Patent-encumbered. In particular: US2009164440, US2009164539.
  - pwg 13y ago
    Those numbers are publication numbers not patent numbers. Only one of the above two actually has become a patent. US20090164440 is patent 8,321,439. You can view the patent here: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8,321,439.PN.&OS=PN/8,321,439&RS=PN/8,321,439 http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=H... The other one is still an application, and so it does not yet patent encumber anything.
    - ioquatix 13y ago
      How the hell did that become a patent? "File system methods and systems enabling efficient detection that a filename exists, by executing a hash function on the file name to reduce the overall computational complexity of determining that a directory entry might match the target filename, prior to performing the string comparison to determine the entry does match the target filename. A cross-device extensible means of providing a conversion function, such as uppercasing the filename, occurs prior to the hash. Methods of creating, deleting, and modifying the directory entries is further provided, as well as details of an embodiment of the file system described."
      - pwg 13y ago
        What became a patent is actually this text: "1. A first one or more computer readable storage media having computer executable instructions that, when executed on at least one processor, configure the at least one processor to perform a method of detecting if a target file name exists on a second one or more computer readable storage media, the method comprising: (A) determining a name hash from the target name; (B) determining if the name hash corresponds to a directory entry set name hash value, the directory entry set name hash value corresponding to one of a plurality of directory entry sets, each of the plurality of directory entry sets stored on the second one or more computer readable storage media; (C) determining if the target name matches a directory entry set name corresponding to the one of the plurality of directory entry sets after step (B) determines the name hash corresponds to the directory entry set name hash value; and (D) indicating that the target name exists after step (C) determines the target name matches the directory entry set name, the step (A) comprising: determining the target name corresponds to one of a predetermined set of names, the predetermined set of names having a common portion; initializing a temporary value to a predetermined start value, the predetermined start value corresponding to a pre-computed partial hash value corresponding to the common portion; for each character of the target name other than the common portion: rotating the temporary value right by at least one bit; converting the character from a first value to a second value based upon a conversion table; and adding the second value to the temporary value; and using the temporary value as the name hash." Not defending it, just pointing out that what's "covered" by a patent is what is in the claims, not the abstract.
- mbreese 13y ago
  I thought it was clear that Microsoft was still asserting patents on exFAT. Link stolen from wikipedia: http://www.microsoft.com/en-us/legal/intellectualproperty/IPLicensing/Programs/exFATFileSystem.aspx http://www.microsoft.com/en-us/legal/intellectualproperty/IP... So, GPL or not, it doesn't do Linux a whole lot of good, since it can never be properly included.
  - 0x0 13y ago
    Is this patent US only? Could one take this code to produce a "EuroLinux" or "AsiaLinux"? Kind of like the "non-US" sections that used to be in Debian?
    - tephra 13y ago
      http://en.wikipedia.org/wiki/Paris_Convention_for_the_Protection_of_Industrial_Property http://en.wikipedia.org/wiki/Paris_Convention_for_the_Protec...
      - 0x0 13y ago
        But http://patents.stackexchange.com/questions/313/are-us-software-patents-enforceable-in-the-uk http://patents.stackexchange.com/questions/313/are-us-softwa... ? (I thought software was considered unpatentable in many areas?)
      - gsnedders 13y ago
        > enjoy in all the other countries of the Union, the advantages that their respective laws grant to nationals This implies that if a patent is filed in one place, then it is effectively filed in all countries of the Union, but one is still bound by the their respective laws, and therefore if they do not recognize your patent as valid then it is not valid in that country.
    - mariuolo 13y ago
      I suppose the module could safely be hosted on non-US repositories.
- zokier 13y ago
  Unclear. GPLv2 has implicit patent grant (see Section 7), so if Samsung has a patent license from MS then that Samsung is required to extend that license to all recipients (direct and indirect) of the code. http://en.swpat.org/wiki/GPLv2_and_patents http://en.swpat.org/wiki/GPLv2_and_patents
  - 0x0 13y ago
    Which of course is no guarantee that they are able to grant, and then you can get in trouble for patent infringement while samsung gets in trouble for distributing software against the terms of the gpl.
    - zmmmmm 13y ago
      Would be fascinating to know how the GPL operates in this case. The way I see it, it can't be that a distributor is liable for patents they do not own on code they distribute. Otherwise the GPL becomes almost non-viable since even the mere act of distributing code under it puts you into the chain of liability. It can only be that you are granting an implicit license for patents you actually own or have the right to re-license.
      - 0x0 13y ago
        Interesting question. Obviously the people behind the LAME MP3 encoder cannot extend you any patent rights on MP3 encoding, you would have to go to MPEG-LA for that. On the other hand, if you take that MP3 encoder and embed it in a device you start selling, you'll most certainly put yourself in the chain of liability, no?
      - belorn 13y ago
        In section 7, it says that distribution is banned if the distributor has patent obligations preventing the recipient from having the four freedoms The distributor is not liable for patents they do not own, but they can loose distribution permission depending on the situation. Same is actually true for anything GPL say. The worst case scenario is always that the distributor loose the permission to distribution, and thus become liable under copyright infringement if they distribute while violating the license.
- rwmj 13y ago
  We have loads of great filesystems already. Use one instead of exFAT. (Yes, I know there exist OSes / devices which only use exFAT, although I've yet to actually use one)
  - regularfry 13y ago
    If you can point me at one that's read/writable out of the box on Windows, OS X and Linux, that'd be grand. last I looked there wasn't one, although UDF came close.
    - deleted 13y ago
      [deleted]
- jwilliams 13y ago
  Microsoft is quite pro-active in tracking and licensing exFAT. They're generally quite polite about it, but insistent (as is their right). I've heard different anecdotes on the price, but it's not cheap. An Ars article from 2009 places the flat fee at $300k[1], although I've heard of niche device manufacturers paying $100k. [1] http://arstechnica.com/information-technology/2009/12/microsoft-licenses-out-exfat-file-system/ http://arstechnica.com/information-technology/2009/12/micros...
ksec 13y ago
Um.... so GPL Code can be Patented??
- jlgreco 13y ago
  Sure. IIRC, even GPLv3 allows it (GPLv3 just requires patent licensing terms iirc).
  - mbreese 13y ago
    This was released under GPLv2, so it may not even require that (iirc2).
    - nknighthb 13y ago
      GPLv2: > 7. If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program. This means anyone distributing this driver -- including Samsung, since they are not the sole copyright holder -- is on, at best, extremely tenuous footing. I don't expect Samsung has license from Microsoft to sublicense the relevant patents to the world.
- makr17 13y ago
  of course, you can gpl-license your implementation of a patented algorithm. the copyright license under which software is offered and any patents associated with underlying algorithms are, I think, orthogonal.
- zokier 13y ago
  At this current state is safest to assume that all code is patented.
maaku 13y ago
I didn't hear about this the first time around so maybe I missed out, but the press release is not clear. It doesn't actually seem like there was a GPL violation. Samsung released a binary in one product. They later applied the GPL to that component as it is used in another project. That shouldn't have any retroactive effect on the first, however. Still great of them to release the earlier code though.
- hosay123 13y ago
  They produced the driver under license, somehow someone got a hold of the code and "guerilla relicensed" it, which they did not have authority to do, and uploaded the result to Github. Sometime later when this repository was noticed on Github, someone noticed the source was a derivation of one of the existing Linux FAT filesystem drivers. In other words, under the terms of the GPL it is derived code. The fact it was only previously distributed in binary form does not excuse this: Samsung were distributing GPL derived code in violation of the license. So this clears things up a little bit. What I don't understand now is the usefulness of this code. For example, could it potentially be merged upstream? If not, then why not? If it can be distributed under the GPL independently, I don't understand why it couldn't get shipped with Linux. The fact this driver exists "legitimately open source" now, yet is still covered by patents, confuses me a bit.
  - 0x0 13y ago
    It's probably in the same situation as ffmpeg, x264, lame, (previously) gif encoders etc are or were. If it is true that non-US countries do not acknowledge the related patents, it would be a very interesting situation if anyone were to make it integrated in a git fork of the mainline kernel. Could we end up having a richer git branch/repo hosted on "kernel.eu"? Would others do pull requests on top of this, thus meaning further kernel patches (related or not so related) get interwoven? Would a "us compatible" mainline linux stagnate while an off-limits-for-americans "eurolinux" flourish? Probably not for just a fringe fs driver that can stay separate. But what about possibly-US-patent-covered patches to the core, if they provide enough benefits?
    - 13y ago
inthewind 13y ago
Not wanting to be tangential but is exFAT any good? And what do others use for a cross platform file system? I sadly had to format a portable 600GB drive as FAT32 the other day, just so it would play ball across OSs and devices. I went to use extFAT, then realised I'd have to use FUSE to get it to work so fell back to FAT32. Also is it backwards compatible with the other FATS; as in can't you read an ext4 as ext3 (hoping that I haven't made that up)?
- archagon 13y ago
  From what I understand (somebody correct me), exFAT is prone to corruption if you unplug an exFAT drive without doing a soft eject first. On the other hand, it's probably the best FS that's natively supported by both OSX and Windows.
- 0x0 13y ago
  It's also significant because it is a part of the SDXC standard.
- mariuolo 13y ago
  Problem is FAT32 can't handle anything beyond 4GiB (or 32 with some trickery) and we've reached that limit. Would you rather use a journaling FS on a flash drive?
  - cbhl 13y ago
    No. Flash drives are slow enough to write to without having to write things (even metadata) twice.
- csense 13y ago
  What about NTFS?
losethos 13y ago
go fish

172 points by 0x0 13y ago

samspenc 13y ago

I remember there was heated discussion about whether the initial "release" was legit or not. Was that ever resolved?

0x0 13y ago
The first version seemed to be a leak with a very unclear licensing situation. This here is the resolution :)
- zokier 13y ago
  The licensing situation of the leak was quite clear; it was proprietary code without any doubt.

regularfry 13y ago

What's the patent status of exFAT?

drdaeman 13y ago
Patent-encumbered. In particular: US2009164440, US2009164539.
- pwg 13y ago
  Those numbers are publication numbers not patent numbers. Only one of the above two actually has become a patent. US20090164440 is patent 8,321,439. You can view the patent here: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8,321,439.PN.&OS=PN/8,321,439&RS=PN/8,321,439 http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=H... The other one is still an application, and so it does not yet patent encumber anything.
  - ioquatix 13y ago
    How the hell did that become a patent? "File system methods and systems enabling efficient detection that a filename exists, by executing a hash function on the file name to reduce the overall computational complexity of determining that a directory entry might match the target filename, prior to performing the string comparison to determine the entry does match the target filename. A cross-device extensible means of providing a conversion function, such as uppercasing the filename, occurs prior to the hash. Methods of creating, deleting, and modifying the directory entries is further provided, as well as details of an embodiment of the file system described."
    - pwg 13y ago
      What became a patent is actually this text: "1. A first one or more computer readable storage media having computer executable instructions that, when executed on at least one processor, configure the at least one processor to perform a method of detecting if a target file name exists on a second one or more computer readable storage media, the method comprising: (A) determining a name hash from the target name; (B) determining if the name hash corresponds to a directory entry set name hash value, the directory entry set name hash value corresponding to one of a plurality of directory entry sets, each of the plurality of directory entry sets stored on the second one or more computer readable storage media; (C) determining if the target name matches a directory entry set name corresponding to the one of the plurality of directory entry sets after step (B) determines the name hash corresponds to the directory entry set name hash value; and (D) indicating that the target name exists after step (C) determines the target name matches the directory entry set name, the step (A) comprising: determining the target name corresponds to one of a predetermined set of names, the predetermined set of names having a common portion; initializing a temporary value to a predetermined start value, the predetermined start value corresponding to a pre-computed partial hash value corresponding to the common portion; for each character of the target name other than the common portion: rotating the temporary value right by at least one bit; converting the character from a first value to a second value based upon a conversion table; and adding the second value to the temporary value; and using the temporary value as the name hash." Not defending it, just pointing out that what's "covered" by a patent is what is in the claims, not the abstract.
mbreese 13y ago
I thought it was clear that Microsoft was still asserting patents on exFAT. Link stolen from wikipedia: http://www.microsoft.com/en-us/legal/intellectualproperty/IPLicensing/Programs/exFATFileSystem.aspx http://www.microsoft.com/en-us/legal/intellectualproperty/IP... So, GPL or not, it doesn't do Linux a whole lot of good, since it can never be properly included.
- 0x0 13y ago
  Is this patent US only? Could one take this code to produce a "EuroLinux" or "AsiaLinux"? Kind of like the "non-US" sections that used to be in Debian?
  - tephra 13y ago
    http://en.wikipedia.org/wiki/Paris_Convention_for_the_Protection_of_Industrial_Property http://en.wikipedia.org/wiki/Paris_Convention_for_the_Protec...
    - 0x0 13y ago
      But http://patents.stackexchange.com/questions/313/are-us-software-patents-enforceable-in-the-uk http://patents.stackexchange.com/questions/313/are-us-softwa... ? (I thought software was considered unpatentable in many areas?)
    - gsnedders 13y ago
      > enjoy in all the other countries of the Union, the advantages that their respective laws grant to nationals This implies that if a patent is filed in one place, then it is effectively filed in all countries of the Union, but one is still bound by the their respective laws, and therefore if they do not recognize your patent as valid then it is not valid in that country.
  - mariuolo 13y ago
    I suppose the module could safely be hosted on non-US repositories.
zokier 13y ago
Unclear. GPLv2 has implicit patent grant (see Section 7), so if Samsung has a patent license from MS then that Samsung is required to extend that license to all recipients (direct and indirect) of the code. http://en.swpat.org/wiki/GPLv2_and_patents http://en.swpat.org/wiki/GPLv2_and_patents
- 0x0 13y ago
  Which of course is no guarantee that they are able to grant, and then you can get in trouble for patent infringement while samsung gets in trouble for distributing software against the terms of the gpl.
  - zmmmmm 13y ago
    Would be fascinating to know how the GPL operates in this case. The way I see it, it can't be that a distributor is liable for patents they do not own on code they distribute. Otherwise the GPL becomes almost non-viable since even the mere act of distributing code under it puts you into the chain of liability. It can only be that you are granting an implicit license for patents you actually own or have the right to re-license.
    - 0x0 13y ago
      Interesting question. Obviously the people behind the LAME MP3 encoder cannot extend you any patent rights on MP3 encoding, you would have to go to MPEG-LA for that. On the other hand, if you take that MP3 encoder and embed it in a device you start selling, you'll most certainly put yourself in the chain of liability, no?
    - belorn 13y ago
      In section 7, it says that distribution is banned if the distributor has patent obligations preventing the recipient from having the four freedoms The distributor is not liable for patents they do not own, but they can loose distribution permission depending on the situation. Same is actually true for anything GPL say. The worst case scenario is always that the distributor loose the permission to distribution, and thus become liable under copyright infringement if they distribute while violating the license.
rwmj 13y ago
We have loads of great filesystems already. Use one instead of exFAT. (Yes, I know there exist OSes / devices which only use exFAT, although I've yet to actually use one)
- regularfry 13y ago
  If you can point me at one that's read/writable out of the box on Windows, OS X and Linux, that'd be grand. last I looked there wasn't one, although UDF came close.
  - deleted 13y ago
    [deleted]
jwilliams 13y ago
Microsoft is quite pro-active in tracking and licensing exFAT. They're generally quite polite about it, but insistent (as is their right). I've heard different anecdotes on the price, but it's not cheap. An Ars article from 2009 places the flat fee at $300k[1], although I've heard of niche device manufacturers paying $100k. [1] http://arstechnica.com/information-technology/2009/12/microsoft-licenses-out-exfat-file-system/ http://arstechnica.com/information-technology/2009/12/micros...

ksec 13y ago

Um.... so GPL Code can be Patented??

jlgreco 13y ago
Sure. IIRC, even GPLv3 allows it (GPLv3 just requires patent licensing terms iirc).
- mbreese 13y ago
  This was released under GPLv2, so it may not even require that (iirc2).
  - nknighthb 13y ago
    GPLv2: > 7. If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program. This means anyone distributing this driver -- including Samsung, since they are not the sole copyright holder -- is on, at best, extremely tenuous footing. I don't expect Samsung has license from Microsoft to sublicense the relevant patents to the world.
makr17 13y ago
of course, you can gpl-license your implementation of a patented algorithm. the copyright license under which software is offered and any patents associated with underlying algorithms are, I think, orthogonal.
zokier 13y ago
At this current state is safest to assume that all code is patented.

maaku 13y ago

I didn't hear about this the first time around so maybe I missed out, but the press release is not clear. It doesn't actually seem like there was a GPL violation. Samsung released a binary in one product. They later applied the GPL to that component as it is used in another project. That shouldn't have any retroactive effect on the first, however. Still great of them to release the earlier code though.

hosay123 13y ago
They produced the driver under license, somehow someone got a hold of the code and "guerilla relicensed" it, which they did not have authority to do, and uploaded the result to Github. Sometime later when this repository was noticed on Github, someone noticed the source was a derivation of one of the existing Linux FAT filesystem drivers. In other words, under the terms of the GPL it is derived code. The fact it was only previously distributed in binary form does not excuse this: Samsung were distributing GPL derived code in violation of the license. So this clears things up a little bit. What I don't understand now is the usefulness of this code. For example, could it potentially be merged upstream? If not, then why not? If it can be distributed under the GPL independently, I don't understand why it couldn't get shipped with Linux. The fact this driver exists "legitimately open source" now, yet is still covered by patents, confuses me a bit.
- 0x0 13y ago
  It's probably in the same situation as ffmpeg, x264, lame, (previously) gif encoders etc are or were. If it is true that non-US countries do not acknowledge the related patents, it would be a very interesting situation if anyone were to make it integrated in a git fork of the mainline kernel. Could we end up having a richer git branch/repo hosted on "kernel.eu"? Would others do pull requests on top of this, thus meaning further kernel patches (related or not so related) get interwoven? Would a "us compatible" mainline linux stagnate while an off-limits-for-americans "eurolinux" flourish? Probably not for just a fringe fs driver that can stay separate. But what about possibly-US-patent-covered patches to the core, if they provide enough benefits?
  - 13y ago

inthewind 13y ago

Not wanting to be tangential but is exFAT any good? And what do others use for a cross platform file system? I sadly had to format a portable 600GB drive as FAT32 the other day, just so it would play ball across OSs and devices. I went to use extFAT, then realised I'd have to use FUSE to get it to work so fell back to FAT32. Also is it backwards compatible with the other FATS; as in can't you read an ext4 as ext3 (hoping that I haven't made that up)?

archagon 13y ago
From what I understand (somebody correct me), exFAT is prone to corruption if you unplug an exFAT drive without doing a soft eject first. On the other hand, it's probably the best FS that's natively supported by both OSX and Windows.
0x0 13y ago
It's also significant because it is a part of the SDXC standard.
mariuolo 13y ago
Problem is FAT32 can't handle anything beyond 4GiB (or 32 with some trickery) and we've reached that limit. Would you rather use a journaling FS on a flash drive?
- cbhl 13y ago
  No. Flash drives are slow enough to write to without having to write things (even metadata) twice.
csense 13y ago
What about NTFS?

losethos 13y ago

go fish