Hi All, I'm trying to get familiar with the bcache internals. I went through this detailed write-up [1] and looked in to the code found in stable Linux kernel release (not the latest bcache code) as well. I have few questions on the topic. Here is my abstract model on how bcache work. - format the caching device and the backing device with its own bucket based file system (bcacheFS) - exposes a virtual block device to the applications (/dev/bcache0) - the data is organized as buckets, indexed by b+tree structures and auxilary search structures. - when a request comes in, search the b+tree based on <inode:offset> and try finding the data on caching device, else send the request to backing device. 1. Why bcache refers to inodes ? The block driver layer does not have an idea about the file system layed on top of it. (ext4). Is this inode refers to device file? As per my understanding the block layer gets bio_structure, it does not have a notion of inodes... 2. How the cache eviction work. ? for an example in processor caches we evict the cache lines within a set in a set associative cache using LRU/etc. How does eviction happens in bcache/policy? 3. Can i use any file system in backing device other than bcacheFS. ? My abstract model on bcache says NO. I'm new to Linux driver programming. so I might be missing few trivial details and hence the confusion.. appreciate if someone can shed some light on the above questions... [1] bcache.evilpiepirate.org/BcacheGuide thanks Pradeep -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
