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Samsung Creates New File System F2Fs For Linux & Android

Posted by Soulskill on from the file-systems-are-for-files dept.

sfcrazy writes "Samsung has created a new Linux file system called F2FS. Jaegeuk Kim of Samsung writes on the Linux Kernel Mailing List: F2FS is a new file system carefully designed for the NAND flash memory-based storage devices. We chose a log structure file system approach, but we tried to adapt it to the new form of storage. Also we remedy some known issues of the very old log structured file system, such as snowball effect of wandering tree and high cleaning overhead."

11 of 140 comments (clear)

  1. Re:Keyword: Android by Xtifr · · Score: 5, Insightful

    Sure, and they might not have released it to the public if it weren't for the GPL. On the other hand, they've developed something that looks like it may be very useful, and have released it without batting an eye. They're one of only seven Platinum members of the Linux Foundation. I think it's clear they understand how the ecosystem works, and they're happy to participate. Hard to fault them for that.

    And actually, as I understand it, they use Linux for a lot more than just Android devices. They also have embedded Linux in other systems, like TVs.

  2. Re:SSD Drives by Anonymous Coward · · Score: 5, Informative

    No. SSDs present themselves to the OS as contiguous block devices. Filesystems intended for bare NAND flash like jffs(2), yaffs, and this new F2Fs would be totally useless for SSDs. They're intended for bare NAND, which SSDs are not.

  3. Re:SSD Drives by gumpish · · Score: 5, Funny

    Did you get the money to buy your SSD drive by going to the ATM machine and entering your PIN number?

  4. Re:Better hurry to the Patent Office by Anonymous Coward · · Score: 5, Funny

    Glad to see proof that Samsung does innovate and not steal everything from AAPL like all Apple Fanboys think.

    What are you talking about? This is clearly a copy of Apple's original filesystem concept THAT THEY INVENTED when they created HFS! Why doesn't Samdung ACTUALLY innovate and find a new way to store data on a collection of sectors instead of just copying Apple all the time.

    The worst part is that Samdung didn't also copy the MARVELOUS AND CLEARLY CORRECT INVENTION of hiding the filesystem (which Apple invented) from the users. They're so far behind Apple that they can only BLATANTLY STEAL the easy parts!

  5. Re:Keyword: Android by MobileTatsu-NJG · · Score: 5, Funny

    And actually, as I understand it, they use Linux for a lot more than just Android devices. They also have embedded Linux in other systems, like TVs.

    Really? Well that explains why my Samsung TV has such a horrible interface*.

    * Kidding. :P

    --

    "I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)

  6. It's not for bare NAND by bogolisk · · Score: 5, Informative

    No. SSDs present themselves to the OS as contiguous block devices. Filesystems intended for bare NAND flash like jffs(2), yaffs, and this new F2Fs would be totally useless for SSDs. They're intended for bare NAND, which SSDs are not.

    You're wrong

    f2fs work on top of block devices. f2fs sends TRIM (ATA command) down to the device. Bare NAND flash doesn't grok ATA commands.

    --
    Bogus
    1. Re:It's not for bare NAND by romiz · · Score: 5, Informative

      The problem is that even with a translation layer for block access, flash-based devices have limitations, which means that different usage patterns can dramatically change the performance of the device.

      For a (simplified) example, to write a file in ext3, you need to store the new data for the file, but you also need to store other metadata: the location of the data blocks themselves in the inode, the file size in the directory, the journaling data. This means that you have four 'internal block descriptors' open for writing at the same time.

      But block descriptors are a limited resource in SSDs, and even more so for low-cost eMMC devices. This means that with only two or three open files with regular writing, you could quite easily lead to some kind of thrashing state, with the device quickly opening and closing descriptors. Since flash memory writing is strongly constrained, this means that a whole block (2 MiB block size is common) containing a descriptor will need to be erased before its next use. As a result, each block only contains little interesting data, and writing only a small amount of data leads to a lot of flash write and erase access. This problem is called write amplification, and reduces both the disk's performance and its durability.

      The F2FS design is a log-based design, where all files on the disk share 6 common writing areas, for each kind of stored data, where the information is stored as it arrives. This will have a very positive effect against the write amplification problem, and is an example of how an adapted file system can have a positive impact, even on block-based devices.

  7. Re:Better hurry to the Patent Office by Anonymous Coward · · Score: 5, Funny

    Apple created the LFS, Litigation File System. The unique innovation looks ahead for a user copying a file from one directory to another, blocks the request, and transfers the operation to a county in Texas to be tied up in I/O for years.

  8. Re:Keyword: Android by GT66 · · Score: 5, Funny

    The irony being that a McDonalds couch would likely contain more actual meat than one of their hamburgers.

  9. Re:exactly by ZeroSumHappiness · · Score: 5, Interesting

    Because it's legally required to trickle down perhaps?

  10. Re:Keyword: Android by Xtifr · · Score: 5, Interesting

    I think Samsung likes Linux a lot

    Considering that a Platinum membership in the Linux Foundation requires plopping down at least half a million bucks, I suspect you're probably right. :)

    Heck, Google only has a Gold membership, and we know they like Linux. Samsung is in elite territory with corporations like IBM and Intel.