fs/ocfs2/move_extents.c

Source file repositories/reference/linux-study-clean/fs/ocfs2/move_extents.c

File Facts

System
Linux kernel
Corpus path
fs/ocfs2/move_extents.c
Extension
.c
Size
26097 bytes
Lines
1095
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct ocfs2_move_extents_context {
	struct inode *inode;
	struct file *file;
	int auto_defrag;
	int partial;
	int credits;
	u32 new_phys_cpos;
	u32 clusters_moved;
	u64 refcount_loc;
	struct ocfs2_move_extents *range;
	struct ocfs2_extent_tree et;
	struct ocfs2_alloc_context *meta_ac;
	struct ocfs2_alloc_context *data_ac;
	struct ocfs2_cached_dealloc_ctxt dealloc;
};

static int __ocfs2_move_extent(handle_t *handle,
			       struct ocfs2_move_extents_context *context,
			       u32 cpos, u32 len, u32 p_cpos, u32 new_p_cpos,
			       int ext_flags)
{
	int ret = 0, index;
	struct inode *inode = context->inode;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_extent_rec *rec, replace_rec;
	struct ocfs2_path *path = NULL;
	struct ocfs2_extent_list *el;
	u64 ino = ocfs2_metadata_cache_owner(context->et.et_ci);
	u64 old_blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cpos);

	ret = ocfs2_duplicate_clusters_by_page(handle, inode, cpos,
					       p_cpos, new_p_cpos, len);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	memset(&replace_rec, 0, sizeof(replace_rec));
	replace_rec.e_cpos = cpu_to_le32(cpos);
	replace_rec.e_leaf_clusters = cpu_to_le16(len);
	replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(inode->i_sb,
								   new_p_cpos));

	path = ocfs2_new_path_from_et(&context->et);
	if (!path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_path(INODE_CACHE(inode), path, cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	el = path_leaf_el(path);

	index = ocfs2_search_extent_list(el, cpos);
	if (index == -1) {
		ret = ocfs2_error(inode->i_sb,
				  "Inode %llu has an extent at cpos %u which can no longer be found\n",
				  (unsigned long long)ino, cpos);
		goto out;
	}

	rec = &el->l_recs[index];

	if (ext_flags != rec->e_flags) {
		ret = ocfs2_error(inode->i_sb,
				  "Inode %llu has corrupted extent %d with flags 0x%x at cpos %u\n",
				  (unsigned long long)ino, index, rec->e_flags, cpos);
		goto out;
	}

	/*
	 * after moving/defraging to new location, the extent is not going
	 * to be refcounted anymore.
	 */
	replace_rec.e_flags = ext_flags & ~OCFS2_EXT_REFCOUNTED;

	ret = ocfs2_split_extent(handle, &context->et, path, index,
				 &replace_rec, context->meta_ac,
				 &context->dealloc);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	context->new_phys_cpos = new_p_cpos;

Annotation

Implementation Notes