I was looking recently and the common task of editing file, while trying to satisfy some of the ACID properties. Atomicity and Consistency are very common requirements and can be achieved by rename(tmp, orig) instead of open(orig, O_TRUNC)+write(). However the downside of that is the awkwardness of maintaining metadata on the tmp file, some of which is impossible to maintain for non root users. OSX has the exchangedata(orig, tmp) call to cater to this problem which would just switch the referenced data while maintaining the orig metadata. So I was wondering about the feasibility of providing that interface, or whether any existing interface caters to that use case? I see XFS has XFS_IOC_SWAPEXT and ext4 has EXT4_IOC_MOVE_EXT which could be useful to implement this? thanks, Pádraig. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
