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/inode.c | 42 +++++++++++++++++++++++++++--------------- 1 file changed, 27 insertions(+), 15 deletions(-) (limited to 'fs/btrfs/inode.c') diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a4157cfdd533..77dd0a776c83 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -51,6 +51,7 @@ #include "compression.h" #include "locking.h" #include "free-space-cache.h" +#include "inode-map.h" struct btrfs_iget_args { u64 ino; @@ -3809,6 +3810,10 @@ void btrfs_evict_inode(struct inode *inode) BUG_ON(ret); } + if (!(root == root->fs_info->tree_root || + root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) + btrfs_return_ino(root, inode->i_ino); + nr = trans->blocks_used; btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root, nr); @@ -4538,6 +4543,12 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, return ERR_PTR(-ENOMEM); } + /* + * we have to initialize this early, so we can reclaim the inode + * number if we fail afterwards in this function. + */ + inode->i_ino = objectid; + if (dir) { trace_btrfs_inode_request(dir); @@ -4583,7 +4594,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, goto fail; inode_init_owner(inode, dir, mode); - inode->i_ino = objectid; inode_set_bytes(inode, 0); inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], @@ -4712,10 +4722,6 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry, if (!new_valid_dev(rdev)) return -EINVAL; - err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid); - if (err) - return err; - /* * 2 for inode item and ref * 2 for dir items @@ -4727,6 +4733,10 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry, btrfs_set_trans_block_group(trans, dir); + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_unlock; + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, dir->i_ino, objectid, BTRFS_I(dir)->block_group, mode, &index); @@ -4774,9 +4784,6 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry, u64 objectid; u64 index = 0; - err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid); - if (err) - return err; /* * 2 for inode item and ref * 2 for dir items @@ -4788,6 +4795,10 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry, btrfs_set_trans_block_group(trans, dir); + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_unlock; + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, dir->i_ino, objectid, BTRFS_I(dir)->block_group, mode, &index); @@ -4902,10 +4913,6 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) u64 index = 0; unsigned long nr = 1; - err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid); - if (err) - return err; - /* * 2 items for inode and ref * 2 items for dir items @@ -4916,6 +4923,10 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) return PTR_ERR(trans); btrfs_set_trans_block_group(trans, dir); + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_fail; + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, dir->i_ino, objectid, BTRFS_I(dir)->block_group, S_IFDIR | mode, @@ -7257,9 +7268,6 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry, if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) return -ENAMETOOLONG; - err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid); - if (err) - return err; /* * 2 items for inode item and ref * 2 items for dir items @@ -7271,6 +7279,10 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry, btrfs_set_trans_block_group(trans, dir); + err = btrfs_find_free_ino(root, &objectid); + if (err) + goto out_unlock; + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, dir->i_ino, objectid, BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO, -- cgit v1.2.3