Hello, I would like to clarify a bit on how the fsync works in btrfs. The log tree journals only the metadata of the files that have been modified prior to the fsync, correct? It does not log the data extents of files, which are directly sync'ed to the disk. Also, if I understand correctly, fsync and fdatasync are the same thing in btrfs currently. Is it more like fsync or fdatasync? What exactly happens once a file inode is in the tree log? Does it mean it is guaranteed to be persisted on disk, or is it already on disk? I see two flags in btrfs_sync_file - BTRFS_INODE_HAS_ASYNC_EXTENT and BTRFS_INODE_NEEDS_FULL_SYNC. I do not fully understand them. After full sync, what does log_dentry_safe and sync_log do? Finally, Wikipedia says that "the items in the log tree are replayed and deleted at the next full tree commit or (if there was a system crash) at the next remount". Even if there is no crash, why is there a need to replay the log? Thanks, Aastha. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
