C++ OCFS2_I函数代码示例

static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
{
	int status;

	status = ocfs2_inode_lock(inode, NULL, 0);
	if (status < 0) {
		mlog_errno(status);
		return status;
	}
	ocfs2_get_inode_flags(OCFS2_I(inode));
	*flags = OCFS2_I(inode)->ip_attr;
	ocfs2_inode_unlock(inode, 0);

	mlog_exit(status);
	return status;
}

static char *ocfs2_fast_symlink_getlink(struct inode *inode,
					struct buffer_head **bh)
{
	int status;
	char *link = NULL;
	struct ocfs2_dinode *fe;

	mlog_entry_void();

	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
				  OCFS2_I(inode)->ip_blkno,
				  bh,
				  OCFS2_BH_CACHED,
				  inode);
	if (status < 0) {
		mlog_errno(status);
		link = ERR_PTR(status);
		goto bail;
	}

	fe = (struct ocfs2_dinode *) (*bh)->b_data;
	link = (char *) fe->id2.i_symlink;
bail:
	mlog_exit(status);

	return link;
}

static struct dentry *ocfs2_get_parent(struct dentry *child)
{
	int status;
	u64 blkno;
	struct dentry *parent;
	struct inode *dir = child->d_inode;

	trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name,
			       (unsigned long long)OCFS2_I(dir)->ip_blkno);

	status = ocfs2_inode_lock(dir, NULL, 0);
	if (status < 0) {
		if (status != -ENOENT)
			mlog_errno(status);
		parent = ERR_PTR(status);
		goto bail;
	}

	status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
	if (status < 0) {
		parent = ERR_PTR(-ENOENT);
		goto bail_unlock;
	}

	parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));

bail_unlock:
	ocfs2_inode_unlock(dir, 0);

bail:
	trace_ocfs2_get_parent_end(parent);

	return parent;
}

/* Called from locking and called from ocfs2_clear_inode. Dump the
 * cache for a given inode.
 *
 * This function is a few more lines longer than necessary due to some
 * accounting done here, but I think it's worth tracking down those
 * bugs sooner -- Mark */
void ocfs2_metadata_cache_purge(struct inode *inode)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	unsigned int tree, to_purge, purged;
	struct ocfs2_caching_info *ci = &oi->ip_metadata_cache;
	struct rb_root root = RB_ROOT;

	spin_lock(&oi->ip_lock);
	tree = !(oi->ip_flags & OCFS2_INODE_CACHE_INLINE);
	to_purge = ci->ci_num_cached;

	mlog(0, "Purge %u %s items from Inode %llu\n", to_purge,
	     tree ? "array" : "tree", (unsigned long long)oi->ip_blkno);

	/* If we're a tree, save off the root so that we can safely
	 * initialize the cache. We do the work to free tree members
	 * without the spinlock. */
	if (tree)
		root = ci->ci_cache.ci_tree;

	ocfs2_metadata_cache_init(inode);
	spin_unlock(&oi->ip_lock);

	purged = ocfs2_purge_copied_metadata_tree(&root);
	/* If possible, track the number wiped so that we can more
	 * easily detect counting errors. Unfortunately, this is only
	 * meaningful for trees. */
	if (tree && purged != to_purge)
		mlog(ML_ERROR, "Inode %llu, count = %u, purged = %u\n",
		     (unsigned long long)oi->ip_blkno, to_purge, purged);
}

static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct page *page = vmf->page;
	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
	struct buffer_head *di_bh = NULL;
	sigset_t blocked, oldset;
	int ret, ret2;

	ret = ocfs2_vm_op_block_sigs(&blocked, &oldset);
	if (ret < 0) {
		mlog_errno(ret);
		return ret;
	}

	/*
	 * The cluster locks taken will block a truncate from another
	 * node. Taking the data lock will also ensure that we don't
	 * attempt page truncation as part of a downconvert.
	 */
	ret = ocfs2_inode_lock(inode, &di_bh, 1);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

	/*
	 * The alloc sem should be enough to serialize with
	 * ocfs2_truncate_file() changing i_size as well as any thread
	 * modifying the inode btree.
	 */
	down_write(&OCFS2_I(inode)->ip_alloc_sem);

	ret = __ocfs2_page_mkwrite(inode, di_bh, page);

	up_write(&OCFS2_I(inode)->ip_alloc_sem);

	brelse(di_bh);
	ocfs2_inode_unlock(inode, 1);

out:
	ret2 = ocfs2_vm_op_unblock_sigs(&oldset);
	if (ret2 < 0)
		mlog_errno(ret2);
	if (ret)
		ret = VM_FAULT_SIGBUS;
	return ret;
}

void ocfs2_metadata_cache_init(struct inode *inode)
{
	struct ocfs2_inode_info *oi = OCFS2_I(inode);
	struct ocfs2_caching_info *ci = &oi->ip_metadata_cache;

	oi->ip_flags |= OCFS2_INODE_CACHE_INLINE;
	ci->ci_num_cached = 0;
}

static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
{
	trace_ocfs2_writepage(
		(unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
		page->index);

	return block_write_full_page(page, ocfs2_get_block, wbc);
}

static struct dentry *ocfs2_get_parent(struct dentry *child)
{
	int status;
	u64 blkno;
	struct dentry *parent;
	struct inode *inode;
	struct inode *dir = child->d_inode;
	struct buffer_head *dirent_bh = NULL;
	struct ocfs2_dir_entry *dirent;

	mlog_entry("(0x%p, '%.*s')\n", child,
		   child->d_name.len, child->d_name.name);

	mlog(0, "find parent of directory %llu\n",
	     (unsigned long long)OCFS2_I(dir)->ip_blkno);

	status = ocfs2_meta_lock(dir, NULL, 0);
	if (status < 0) {
		if (status != -ENOENT)
			mlog_errno(status);
		parent = ERR_PTR(status);
		goto bail;
	}

	status = ocfs2_find_files_on_disk("..", 2, &blkno, dir, &dirent_bh,
					  &dirent);
	if (status < 0) {
		parent = ERR_PTR(-ENOENT);
		goto bail_unlock;
	}

	inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0);
	if (IS_ERR(inode)) {
		mlog(ML_ERROR, "Unable to create inode %llu\n",
		     (unsigned long long)blkno);
		parent = ERR_PTR(-EACCES);
		goto bail_unlock;
	}

	parent = d_alloc_anon(inode);
	if (!parent) {
		iput(inode);
		parent = ERR_PTR(-ENOMEM);
	}

	parent->d_op = &ocfs2_dentry_ops;

bail_unlock:
	ocfs2_meta_unlock(dir, 0);

	if (dirent_bh)
		brelse(dirent_bh);

bail:
	mlog_exit_ptr(parent);

	return parent;
}

static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
{
	sector_t status;
	u64 p_blkno = 0;
	int err = 0;
	struct inode *inode = mapping->host;

	mlog_entry("(block = %llu)\n", (unsigned long long)block);

	/* We don't need to lock journal system files, since they aren't
	 * accessed concurrently from multiple nodes.
	 */
	if (!INODE_JOURNAL(inode)) {
		err = ocfs2_inode_lock(inode, NULL, 0);
		if (err) {
			if (err != -ENOENT)
				mlog_errno(err);
			goto bail;
		}
		down_read(&OCFS2_I(inode)->ip_alloc_sem);
	}

	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
		err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
						  NULL);

	if (!INODE_JOURNAL(inode)) {
		up_read(&OCFS2_I(inode)->ip_alloc_sem);
		ocfs2_inode_unlock(inode, 0);
	}

	if (err) {
		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
		     (unsigned long long)block);
		mlog_errno(err);
		goto bail;
	}

bail:
	status = err ? 0 : p_blkno;

	mlog_exit((int)status);

	return status;
}

int ocfs2_extent_map_init(struct inode *inode)
{
	struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;

	em->em_extents = RB_ROOT;
	em->em_clusters = 0;

	return 0;
}

static int ocfs2_block_group_fill(handle_t *handle,
				  struct inode *alloc_inode,
				  struct buffer_head *bg_bh,
				  u64 group_blkno,
				  u16 my_chain,
				  struct ocfs2_chain_list *cl)
{
	int status = 0;
	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
	struct super_block * sb = alloc_inode->i_sb;

	mlog_entry_void();

	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
		ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
			    "b_blocknr (%llu)",
			    (unsigned long long)group_blkno,
			    (unsigned long long) bg_bh->b_blocknr);
		status = -EIO;
		goto bail;
	}

	status = ocfs2_journal_access(handle,
				      alloc_inode,
				      bg_bh,
				      OCFS2_JOURNAL_ACCESS_CREATE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	memset(bg, 0, sb->s_blocksize);
	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
	bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
	bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
	bg->bg_chain = cpu_to_le16(my_chain);
	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
	bg->bg_blkno = cpu_to_le64(group_blkno);
	/* set the 1st bit in the bitmap to account for the descriptor block */
	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);

	status = ocfs2_journal_dirty(handle, bg_bh);
	if (status < 0)
		mlog_errno(status);

	/* There is no need to zero out or otherwise initialize the
	 * other blocks in a group - All valid FS metadata in a block
	 * group stores the superblock fs_generation value at
	 * allocation time. */

bail:
	mlog_exit(status);
	return status;
}

/* Support function for ocfs2_delete_inode. Will help us keep the
 * inode data in a consistent state for clear_inode. Always truncates
 * pages, optionally sync's them first. */
static void ocfs2_cleanup_delete_inode(struct inode *inode,
				       int sync_data)
{
	mlog(0, "Cleanup inode %llu, sync = %d\n",
	     (unsigned long long)OCFS2_I(inode)->ip_blkno, sync_data);
	if (sync_data)
		write_inode_now(inode, 1);
	truncate_inode_pages(&inode->i_data, 0);
}

/* Support function for ocfs2_delete_inode. Will help us keep the
 * inode data in a consistent state for clear_inode. Always truncates
 * pages, optionally sync's them first. */
static void ocfs2_cleanup_delete_inode(struct inode *inode,
				       int sync_data)
{
	trace_ocfs2_cleanup_delete_inode(
		(unsigned long long)OCFS2_I(inode)->ip_blkno, sync_data);
	if (sync_data)
		filemap_write_and_wait(inode->i_mapping);
	truncate_inode_pages(&inode->i_data, 0);
}

/*
 * TODO: this should probably be merged into ocfs2_get_block
 *
 * However, you now need to pay attention to the cont_prepare_write()
 * stuff in ocfs2_get_block (that is, ocfs2_get_block pretty much
 * expects never to extend).
 */
struct buffer_head *ocfs2_bread(struct inode *inode,
				int block, int *err, int reada)
{
	struct buffer_head *bh = NULL;
	int tmperr;
	u64 p_blkno;
	int readflags = OCFS2_BH_CACHED;

	if (reada)
		readflags |= OCFS2_BH_READAHEAD;

	if (((u64)block << inode->i_sb->s_blocksize_bits) >=
	    i_size_read(inode)) {
		BUG_ON(!reada);
		return NULL;
	}

	down_read(&OCFS2_I(inode)->ip_alloc_sem);
	tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
					     NULL);
	up_read(&OCFS2_I(inode)->ip_alloc_sem);
	if (tmperr < 0) {
		mlog_errno(tmperr);
		goto fail;
	}

	tmperr = ocfs2_read_block(OCFS2_SB(inode->i_sb), p_blkno, &bh,
				  readflags, inode);
	if (tmperr < 0)
		goto fail;

	tmperr = 0;

	*err = 0;
	return bh;

fail:
	if (bh) {
		brelse(bh);
		bh = NULL;
	}
	*err = -EIO;
	return NULL;
}

static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
        int type,
        u32 slot)
{
    char namebuf[40];
    struct inode *inode = NULL;
    u64 blkno;
    int status = 0;

    ocfs2_sprintf_system_inode_name(namebuf,
                                    sizeof(namebuf),
                                    type, slot);

    status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
                                        strlen(namebuf), &blkno);
    if (status < 0) {
        goto bail;
    }

    inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
    if (IS_ERR(inode)) {
        mlog_errno(PTR_ERR(inode));
        inode = NULL;
        goto bail;
    }
#ifdef CONFIG_DEBUG_LOCK_ALLOC
    if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
            type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
            type == JOURNAL_SYSTEM_INODE) {
        /* Ignore inode lock on these inodes as the lock does not
         * really belong to any process and lockdep cannot handle
         * that */
        OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
    } else {
        lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
                         l_lockdep_map,
                         ocfs2_system_inodes[type].si_name,
                         &ocfs2_sysfile_cluster_lock_key[type], 0);
    }
#endif
bail:

    return inode;
}