nilfs2: remove own inode hash used for GC
This uses inode hash function that vfs provides instead of the own
hash table for caching gc inodes. This finally removes the own inode
hash from nilfs.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/gcinode.c b/fs/nilfs2/gcinode.c
index cd19a37..34f8f84 100644
--- a/fs/nilfs2/gcinode.c
+++ b/fs/nilfs2/gcinode.c
@@ -28,13 +28,6 @@
* gcinodes), and this file provides lookup function of the dummy
* inodes and their buffer read function.
*
- * Since NILFS2 keeps up multiple checkpoints/snapshots across GC, it
- * has to treat blocks that belong to a same file but have different
- * checkpoint numbers. To avoid interference among generations, dummy
- * inodes are managed separately from actual inodes, and their lookup
- * function (nilfs_gc_iget) is designed to be specified with a
- * checkpoint number argument as well as an inode number.
- *
* Buffers and pages held by the dummy inodes will be released each
* time after they are copied to a new log. Dirty blocks made on the
* current generation and the blocks to be moved by GC never overlap
@@ -180,124 +173,41 @@
return 0;
}
-/*
- * nilfs_init_gccache() - allocate and initialize gc_inode hash table
- * @nilfs - the_nilfs
- *
- * Return Value: On success, 0.
- * On error, a negative error code is returned.
- */
-int nilfs_init_gccache(struct the_nilfs *nilfs)
+int nilfs_init_gcinode(struct inode *inode)
{
- int loop;
+ struct nilfs_inode_info *ii = NILFS_I(inode);
+ struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
+ int ret;
- BUG_ON(nilfs->ns_gc_inodes_h);
+ ret = nilfs_mdt_init(inode, nilfs, GFP_NOFS, 0);
+ if (!ret) {
+ inode->i_mapping->a_ops = &def_gcinode_aops;
- INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
+ ii->i_flags = 0;
+ nilfs_bmap_init_gc(ii->i_bmap);
- nilfs->ns_gc_inodes_h =
- kmalloc(sizeof(struct hlist_head) * NILFS_GCINODE_HASH_SIZE,
- GFP_NOFS);
- if (nilfs->ns_gc_inodes_h == NULL)
- return -ENOMEM;
-
- for (loop = 0; loop < NILFS_GCINODE_HASH_SIZE; loop++)
- INIT_HLIST_HEAD(&nilfs->ns_gc_inodes_h[loop]);
- return 0;
-}
-
-/*
- * nilfs_destroy_gccache() - free gc_inode hash table
- * @nilfs - the nilfs
- */
-void nilfs_destroy_gccache(struct the_nilfs *nilfs)
-{
- if (nilfs->ns_gc_inodes_h) {
- nilfs_remove_all_gcinode(nilfs);
- kfree(nilfs->ns_gc_inodes_h);
- nilfs->ns_gc_inodes_h = NULL;
- }
-}
-
-static struct inode *alloc_gcinode(struct the_nilfs *nilfs, ino_t ino,
- __u64 cno)
-{
- struct inode *inode;
- struct nilfs_inode_info *ii;
-
- inode = nilfs_mdt_new_common(nilfs, NULL, ino);
- if (!inode)
- return NULL;
-
- if (nilfs_mdt_init(inode, nilfs, GFP_NOFS, 0) < 0) {
- nilfs_destroy_inode(inode);
- return NULL;
- }
- inode->i_op = NULL;
- inode->i_fop = NULL;
- inode->i_mapping->a_ops = &def_gcinode_aops;
-
- ii = NILFS_I(inode);
- ii->i_cno = cno;
- ii->i_flags = 0;
- ii->i_state = 1 << NILFS_I_GCINODE;
- ii->i_bh = NULL;
- nilfs_bmap_init_gc(ii->i_bmap);
-
- return inode;
-}
-
-static unsigned long ihash(ino_t ino, __u64 cno)
-{
- return hash_long((unsigned long)((ino << 2) + cno),
- NILFS_GCINODE_HASH_BITS);
-}
-
-/*
- * nilfs_gc_iget() - find or create gc inode with specified (ino,cno)
- */
-struct inode *nilfs_gc_iget(struct the_nilfs *nilfs, ino_t ino, __u64 cno)
-{
- struct hlist_head *head = nilfs->ns_gc_inodes_h + ihash(ino, cno);
- struct hlist_node *node;
- struct inode *inode;
-
- hlist_for_each_entry(inode, node, head, i_hash) {
- if (inode->i_ino == ino && NILFS_I(inode)->i_cno == cno)
- return inode;
- }
-
- inode = alloc_gcinode(nilfs, ino, cno);
- if (likely(inode)) {
- hlist_add_head(&inode->i_hash, head);
+ /*
+ * Add the inode to GC inode list. Garbage Collection
+ * is serialized and no two processes manipulate the
+ * list simultaneously.
+ */
+ igrab(inode);
list_add(&NILFS_I(inode)->i_dirty, &nilfs->ns_gc_inodes);
}
- return inode;
+ return ret;
}
-/*
- * nilfs_clear_gcinode() - clear and free a gc inode
+/**
+ * nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes
*/
-void nilfs_clear_gcinode(struct inode *inode)
+void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs)
{
- nilfs_mdt_destroy(inode);
-}
+ struct list_head *head = &nilfs->ns_gc_inodes;
+ struct nilfs_inode_info *ii;
-/*
- * nilfs_remove_all_gcinode() - remove all inodes from the_nilfs
- */
-void nilfs_remove_all_gcinode(struct the_nilfs *nilfs)
-{
- struct hlist_head *head = nilfs->ns_gc_inodes_h;
- struct hlist_node *node, *n;
- struct inode *inode;
- int loop;
-
- for (loop = 0; loop < NILFS_GCINODE_HASH_SIZE; loop++, head++) {
- hlist_for_each_entry_safe(inode, node, n, head, i_hash) {
- hlist_del_init(&inode->i_hash);
- list_del_init(&NILFS_I(inode)->i_dirty);
- nilfs_clear_gcinode(inode); /* might sleep */
- }
+ while (!list_empty(head)) {
+ ii = list_first_entry(head, struct nilfs_inode_info, i_dirty);
+ list_del_init(&ii->i_dirty);
+ iput(&ii->vfs_inode);
}
}