From 581bb050941b4f220f84d3e5ed6dace3d42dd382 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 20 Apr 2011 10:06:11 +0800 Subject: Btrfs: Cache free inode numbers in memory Currently btrfs stores the highest objectid of the fs tree, and it always returns (highest+1) inode number when we create a file, so inode numbers won't be reclaimed when we delete files, so we'll run out of inode numbers as we keep create/delete files in 32bits machines. This fixes it, and it works similarly to how we cache free space in block cgroups. We start a kernel thread to read the file tree. By scanning inode items, we know which chunks of inode numbers are free, and we cache them in an rb-tree. Because we are searching the commit root, we have to carefully handle the cross-transaction case. The rb-tree is a hybrid extent+bitmap tree, so if we have too many small chunks of inode numbers, we'll use bitmaps. Initially we allow 16K ram of extents, and a bitmap will be used if we exceed this threshold. The extents threshold is adjusted in runtime. Signed-off-by: Li Zefan --- fs/btrfs/relocation.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/btrfs/relocation.c') diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 58250e09eb0..e6cb8935725 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -30,6 +30,7 @@ #include "btrfs_inode.h" #include "async-thread.h" #include "free-space-cache.h" +#include "inode-map.h" /* * backref_node, mapping_node and tree_block start with this @@ -3897,7 +3898,7 @@ struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info, if (IS_ERR(trans)) return ERR_CAST(trans); - err = btrfs_find_free_objectid(trans, root, objectid, &objectid); + err = btrfs_find_free_objectid(root, &objectid); if (err) goto out; -- cgit v1.2.3-70-g09d2