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path: root/fs/btrfs/free-space-cache.c
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* Btrfs: Fix checkpatch.pl warningsChris Mason2009-01-051-16/+21
| | | | | | | There were many, most are fixed now. struct-funcs.c generates some warnings but these are bogus. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: superblock duplicationYan Zheng2008-12-081-1/+0
| | | | | | | | | | | This patch implements superblock duplication. Superblocks are stored at offset 16K, 64M and 256G on every devices. Spaces used by superblocks are preserved by the allocator, which uses a reverse mapping function to find the logical addresses that correspond to superblocks. Thank you, Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: make things static and include the right headersChristoph Hellwig2008-12-021-2/+4
| | | | | | | | Shut up various sparse warnings about symbols that should be either static or have their declarations in scope. Signed-off-by: Christoph Hellwig <hch@lst.de>
* Btrfs: nuke fs wide allocation mutex V2Josef Bacik2008-10-291-26/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the giant fs_info->alloc_mutex and replaces it with a bunch of little locks. There is now a pinned_mutex, which is used when messing with the pinned_extents extent io tree, and the extent_ins_mutex which is used with the pending_del and extent_ins extent io trees. The locking for the extent tree stuff was inspired by a patch that Yan Zheng wrote to fix a race condition, I cleaned it up some and changed the locking around a little bit, but the idea remains the same. Basically instead of holding the extent_ins_mutex throughout the processing of an extent on the extent_ins or pending_del trees, we just hold it while we're searching and when we clear the bits on those trees, and lock the extent for the duration of the operations on the extent. Also to keep from getting hung up waiting to lock an extent, I've added a try_lock_extent so if we cannot lock the extent, move on to the next one in the tree and we'll come back to that one. I have tested this heavily and it does not appear to break anything. This has to be applied on top of my find_free_extent redo patch. I tested this patch on top of Yan's space reblancing code and it worked fine. The only thing that has changed since the last version is I pulled out all my debugging stuff, apparently I forgot to run guilt refresh before I sent the last patch out. Thank you, Signed-off-by: Josef Bacik <jbacik@redhat.com>
* Btrfs: make tree_search_offset more flexible in its searchingJosef Bacik2008-10-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | Sometimes we end up freeing a reserved extent because we don't need it, however this means that its possible for transaction->last_alloc to point to the middle of a free area. When we search for free space in find_free_space we do a tree_search_offset with contains set to 0, because we want it to find the next best free area if we do not have an offset starting on the given offset. Unfortunately that currently means that if the offset we were given as a hint points to the middle of a free area, we won't find anything. This is especially bad if we happened to last allocate from the big huge chunk of a newly formed block group, since we won't find anything and have to go back and search the long way around. This fixes this problem by making it so that we return the free space area regardless of the contains variable. This made cache missing happen _alot_ less, and speeds things up considerably. Signed-off-by: Josef Bacik <jbacik@redhat.com>
* Btrfs: Fix allocation completions in tree log replayChris Mason2008-09-251-0/+34
| | | | | | | | | | | | After a crash, the tree log code uses btrfs_alloc_logged_extent to record allocations of data extents that it finds in the log tree. These come in basically random order, which does not fit how btrfs_remove_free_space() expects to be called. btrfs_remove_free_space was changed to support recording an extent allocation in the middle of a region of free space. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: free space accounting redoJosef Bacik2008-09-251-0/+415
1) replace the per fs_info extent_io_tree that tracked free space with two rb-trees per block group to track free space areas via offset and size. The reason to do this is because most allocations come with a hint byte where to start, so we can usually find a chunk of free space at that hint byte to satisfy the allocation and get good space packing. If we cannot find free space at or after the given offset we fall back on looking for a chunk of the given size as close to that given offset as possible. When we fall back on the size search we also try to find a slot as close to the size we want as possible, to avoid breaking small chunks off of huge areas if possible. 2) remove the extent_io_tree that tracked the block group cache from fs_info and replaced it with an rb-tree thats tracks block group cache via offset. also added a per space_info list that tracks the block group cache for the particular space so we can lookup related block groups easily. 3) cleaned up the allocation code to make it a little easier to read and a little less complicated. Basically there are 3 steps, first look from our provided hint. If we couldn't find from that given hint, start back at our original search start and look for space from there. If that fails try to allocate space if we can and start looking again. If not we're screwed and need to start over again. 4) small fixes. there were some issues in volumes.c where we wouldn't allocate the rest of the disk. fixed cow_file_range to actually pass the alloc_hint, which has helped a good bit in making the fs_mark test I run have semi-normal results as we run out of space. Generally with data allocations we don't track where we last allocated from, so everytime we did a data allocation we'd search through every block group that we have looking for free space. Now searching a block group with no free space isn't terribly time consuming, it was causing a slight degradation as we got more data block groups. The alloc_hint has fixed this slight degredation and made things semi-normal. There is still one nagging problem I'm working on where we will get ENOSPC when there is definitely plenty of space. This only happens with metadata allocations, and only when we are almost full. So you generally hit the 85% mark first, but sometimes you'll hit the BUG before you hit the 85% wall. I'm still tracking it down, but until then this seems to be pretty stable and make a significant performance gain. Signed-off-by: Chris Mason <chris.mason@oracle.com>
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