diff options
| -rw-r--r-- | fs/nilfs2/gcinode.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/fs/nilfs2/gcinode.c b/fs/nilfs2/gcinode.c new file mode 100644 index 00000000000..00139526632 --- /dev/null +++ b/fs/nilfs2/gcinode.c @@ -0,0 +1,270 @@ +/* + * gcinode.c - NILFS memory inode for GC + * + * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Written by Seiji Kihara <kihara@osrg.net>, Amagai Yoshiji <amagai@osrg.net>, + * and Ryusuke Konishi <ryusuke@osrg.net>. + * Revised by Ryusuke Konishi <ryusuke@osrg.net>. + * + */ + +#include <linux/buffer_head.h> +#include <linux/mpage.h> +#include <linux/hash.h> +#include <linux/swap.h> +#include "nilfs.h" +#include "page.h" +#include "mdt.h" +#include "dat.h" +#include "ifile.h" + +static struct address_space_operations def_gcinode_aops = {}; +/* XXX need def_gcinode_iops/fops? */ + +/* + * nilfs_gccache_submit_read_data() - add data buffer and submit read request + * @inode - gc inode + * @blkoff - dummy offset treated as the key for the page cache + * @pbn - physical block number of the block + * @vbn - virtual block number of the block, 0 for non-virtual block + * @out_bh - indirect pointer to a buffer_head struct to receive the results + * + * Description: nilfs_gccache_submit_read_data() registers the data buffer + * specified by @pbn to the GC pagecache with the key @blkoff. + * This function sets @vbn (@pbn if @vbn is zero) in b_blocknr of the buffer. + * + * Return Value: On success, 0 is returned. On Error, one of the following + * negative error code is returned. + * + * %-EIO - I/O error. + * + * %-ENOMEM - Insufficient amount of memory available. + * + * %-ENOENT - The block specified with @pbn does not exist. + */ +int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff, + sector_t pbn, __u64 vbn, + struct buffer_head **out_bh) +{ + struct buffer_head *bh; + int err; + + bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0); + if (unlikely(!bh)) + return -ENOMEM; + + if (buffer_uptodate(bh)) + goto out; + + if (pbn == 0) { + struct inode *dat_inode = NILFS_I_NILFS(inode)->ns_dat; + /* use original dat, not gc dat. */ + err = nilfs_dat_translate(dat_inode, vbn, &pbn); + if (unlikely(err)) { /* -EIO, -ENOMEM, -ENOENT */ + brelse(bh); + goto failed; + } + } + + lock_buffer(bh); + if (buffer_uptodate(bh)) { + unlock_buffer(bh); + goto out; + } + + if (!buffer_mapped(bh)) { + bh->b_bdev = NILFS_I_NILFS(inode)->ns_bdev; + set_buffer_mapped(bh); + } + bh->b_blocknr = pbn; + bh->b_end_io = end_buffer_read_sync; + get_bh(bh); + submit_bh(READ, bh); + if (vbn) + bh->b_blocknr = vbn; + out: + err = 0; + *out_bh = bh; + + failed: + unlock_page(bh->b_page); + page_cache_release(bh->b_page); + return err; +} + +/* + * nilfs_gccache_submit_read_node() - add node buffer and submit read request + * @inode - gc inode + * @pbn - physical block number for the block + * @vbn - virtual block number for the block + * @out_bh - indirect pointer to a buffer_head struct to receive the results + * + * Description: nilfs_gccache_submit_read_node() registers the node buffer + * specified by @vbn to the GC pagecache. @pbn can be supplied by the + * caller to avoid translation of the disk block address. + * + * Return Value: On success, 0 is returned. On Error, one of the following + * negative error code is returned. + * + * %-EIO - I/O error. + * + * %-ENOMEM - Insufficient amount of memory available. + */ +int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn, + __u64 vbn, struct buffer_head **out_bh) +{ + int ret = nilfs_btnode_submit_block(&NILFS_I(inode)->i_btnode_cache, + vbn ? : pbn, pbn, out_bh, 0); + if (ret == -EEXIST) /* internal code (cache hit) */ + ret = 0; + return ret; +} + +int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh) +{ + wait_on_buffer(bh); + if (!buffer_uptodate(bh)) + return -EIO; + if (buffer_dirty(bh)) + return -EEXIST; + + if (buffer_nilfs_node(bh)) + nilfs_btnode_mark_dirty(bh); + else + nilfs_mdt_mark_buffer_dirty(bh); + 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 loop; + + BUG_ON(nilfs->ns_gc_inodes_h); + + INIT_LIST_HEAD(&nilfs->ns_gc_inodes); + + 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 = nilfs_mdt_new_common(nilfs, NULL, ino, GFP_NOFS); + struct nilfs_inode_info *ii; + + if (!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; + ii->i_dtime = 0; + 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); + list_add(&NILFS_I(inode)->i_dirty, &nilfs->ns_gc_inodes); + } + return inode; +} + +/* + * nilfs_clear_gcinode() - clear and free a gc inode + */ +void nilfs_clear_gcinode(struct inode *inode) +{ + nilfs_mdt_clear(inode); + nilfs_mdt_destroy(inode); +} + +/* + * 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 */ + } + } +} |