3 ms·
> The throwaway acccount is right. > In POSIX, file content data and metadata (directory entries) are separate. Atomicity and durability are separate. > It is
by aidenn0 3y ago
> The throwaway acccount is right.
> In POSIX, file content data and metadata (directory entries) are separate. Atomicity and durability are separate.
> It is likely that the LWN post author understands this very well, but omitted this important info from the article.
1. If the author understands this, then the throwaway is wrong, since they claimed the author didn't know this.
2. The entire point of TFA was that POSIX is underspecified here, so I think they covered it sufficiently; something that worked on FFS didn't work on ext4, and the suggestion is that it should work going forwards, regardless of what POSIX requires.
- throwaway09223 3y agoPOSIX isn't underspecified here. rename() has no durability guarantees. That's the answer. "something that worked on FFS didn't work on ext4," As the article notes this is NOT durable on FFS. Early FFS (and early ext) could lose the entire filesystem after a crash. ext2 still can. ext4 is the oddball here. TFA is not framing things correctly.