Hi, while reading btrfs source code, I try to make sense of the various uses of block reserves. The working theory is as follows:
1. Every operation has to reserve upfront every single byte it needs to complete its operation fully. 2. If an operation cannot determine how much space it will need, it has to be able to cope with running out of space. Normally it does it by inserting an orphan item, doing its work in multiple transactions and removing the orphan item. The commits in between normally free up enough space to continue the operation. 3. All other enospc situations are errors in program logic and should result in BUG_ON. It would be great of someone with a deeper knowledge could correct, expand or just confirm this. Thanks, Arne -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
