* F2FS Superblock Locations @ 2013-10-31 1:06 Zachary 2013-10-31 1:55 ` Jaegeuk Kim 0 siblings, 1 reply; 4+ messages in thread From: Zachary @ 2013-10-31 1:06 UTC (permalink / raw) To: linux-f2fs-devel [-- Attachment #1.1: Type: text/plain, Size: 551 bytes --] Hello, Recently I was checking the file format for F2FS and noticed that the superblocks' location on the partition was both at the beginning. This means that if a large portion of the partition is corrupted, then it is possible for both superblocks to be destroyed. From my understanding of other filesystems, they prevent that by spreading out the superbolock backups across the partition so that it reduces the chances of all superblocks being destroyed. Has this been noticed before or am I mistaken in some way? Thank you, Zachary Winnerman [-- Attachment #1.2: Type: text/html, Size: 598 bytes --] [-- Attachment #2: Type: text/plain, Size: 402 bytes --] ------------------------------------------------------------------------------ Android is increasing in popularity, but the open development platform that developers love is also attractive to malware creators. Download this white paper to learn more about secure code signing practices that can help keep Android apps secure. http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktrk [-- Attachment #3: Type: text/plain, Size: 179 bytes --] _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: F2FS Superblock Locations 2013-10-31 1:06 F2FS Superblock Locations Zachary @ 2013-10-31 1:55 ` Jaegeuk Kim 2013-10-31 3:33 ` Zachary 0 siblings, 1 reply; 4+ messages in thread From: Jaegeuk Kim @ 2013-10-31 1:55 UTC (permalink / raw) To: Zachary; +Cc: linux-f2fs-devel Hi, 2013-10-30 (수), 21:06 -0400, Zachary: > Hello, > > Recently I was checking the file format for F2FS and noticed that the > superblocks' location on the partition was both at the beginning. > This means that if a large portion of the partition is corrupted, then > it is possible for both superblocks to be destroyed. From my > understanding of other filesystems, they prevent that by spreading out > the superbolock backups across the partition so that it reduces the > chances of all superblocks being destroyed. Has this been noticed > before or am I mistaken in some way? IMHO, traditional rotational disks like HDDs need such the superblock backups. But for the solid-state disks like SSDs and eMMCs, I suspect that the backups are needed in practical, since its firmware, FTL, spreads the data across the whole NAND arrays to avoid cell errors (e.g., wear-out). So I think the superblock is very much hard to be broken especially on flash storages. Thank you, -- Jaegeuk Kim Samsung ------------------------------------------------------------------------------ Android is increasing in popularity, but the open development platform that developers love is also attractive to malware creators. Download this white paper to learn more about secure code signing practices that can help keep Android apps secure. http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktrk _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: F2FS Superblock Locations 2013-10-31 1:55 ` Jaegeuk Kim @ 2013-10-31 3:33 ` Zachary 2013-10-31 5:00 ` Jaegeuk Kim 0 siblings, 1 reply; 4+ messages in thread From: Zachary @ 2013-10-31 3:33 UTC (permalink / raw) To: jaegeuk.kim; +Cc: linux-f2fs-devel [-- Attachment #1.1: Type: text/plain, Size: 1358 bytes --] This was in reference to software mistakes that might wipe portions of the disk rather than hardware failures, it came up after I almost had one though it turns out its an unrelated problem. On Oct 30, 2013 9:56 PM, "Jaegeuk Kim" <jaegeuk.kim@samsung.com> wrote: > Hi, > > 2013-10-30 (수), 21:06 -0400, Zachary: > > Hello, > > > > Recently I was checking the file format for F2FS and noticed that the > > superblocks' location on the partition was both at the beginning. > > This means that if a large portion of the partition is corrupted, then > > it is possible for both superblocks to be destroyed. From my > > understanding of other filesystems, they prevent that by spreading out > > the superbolock backups across the partition so that it reduces the > > chances of all superblocks being destroyed. Has this been noticed > > before or am I mistaken in some way? > > IMHO, traditional rotational disks like HDDs need such the superblock > backups. > > But for the solid-state disks like SSDs and eMMCs, I suspect that the > backups are needed in practical, since its firmware, FTL, spreads the > data across the whole NAND arrays to avoid cell errors (e.g., wear-out). > So I think the superblock is very much hard to be broken especially on > flash storages. > > Thank you, > > > -- > Jaegeuk Kim > Samsung > > [-- Attachment #1.2: Type: text/html, Size: 1703 bytes --] [-- Attachment #2: Type: text/plain, Size: 402 bytes --] ------------------------------------------------------------------------------ Android is increasing in popularity, but the open development platform that developers love is also attractive to malware creators. Download this white paper to learn more about secure code signing practices that can help keep Android apps secure. http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktrk [-- Attachment #3: Type: text/plain, Size: 179 bytes --] _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: F2FS Superblock Locations 2013-10-31 3:33 ` Zachary @ 2013-10-31 5:00 ` Jaegeuk Kim 0 siblings, 0 replies; 4+ messages in thread From: Jaegeuk Kim @ 2013-10-31 5:00 UTC (permalink / raw) To: Zachary; +Cc: linux-f2fs-devel 2013-10-30 (수), 23:33 -0400, Zachary: > This was in reference to software mistakes that might wipe portions of > the disk rather than hardware failures, it came up after I almost had > one though it turns out its an unrelated problem. If this is due to the SW mistakes, it would be better to rewrite the superblock only by mkfs.f2fs, since the superblock contains just static information of its partition. I can simply add an option to do that in mkfs.f2fs. But, if the checkpoint is corrupted, there is no way to recover. Thanks, > > On Oct 30, 2013 9:56 PM, "Jaegeuk Kim" <jaegeuk.kim@samsung.com> > wrote: > Hi, > > 2013-10-30 (수), 21:06 -0400, Zachary: > > Hello, > > > > Recently I was checking the file format for F2FS and noticed > that the > > superblocks' location on the partition was both at the > beginning. > > This means that if a large portion of the partition is > corrupted, then > > it is possible for both superblocks to be destroyed. From > my > > understanding of other filesystems, they prevent that by > spreading out > > the superbolock backups across the partition so that it > reduces the > > chances of all superblocks being destroyed. Has this been > noticed > > before or am I mistaken in some way? > > IMHO, traditional rotational disks like HDDs need such the > superblock > backups. > > But for the solid-state disks like SSDs and eMMCs, I suspect > that the > backups are needed in practical, since its firmware, FTL, > spreads the > data across the whole NAND arrays to avoid cell errors (e.g., > wear-out). > So I think the superblock is very much hard to be broken > especially on > flash storages. > > Thank you, > > > -- > Jaegeuk Kim > Samsung > -- Jaegeuk Kim Samsung ------------------------------------------------------------------------------ Android is increasing in popularity, but the open development platform that developers love is also attractive to malware creators. Download this white paper to learn more about secure code signing practices that can help keep Android apps secure. http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktrk _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-10-31 5:00 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-10-31 1:06 F2FS Superblock Locations Zachary 2013-10-31 1:55 ` Jaegeuk Kim 2013-10-31 3:33 ` Zachary 2013-10-31 5:00 ` Jaegeuk Kim
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