[Ocfs2-devel] [PATCH 10/42] ocfs2: Abstract extent split process.
Tao Ma
tao.ma at oracle.com
Thu Apr 2 16:45:49 PDT 2009
ocfs2_mark_extent_written actually does the following things:
1. check the parameters.
2. initialize the left_path and split_rec.
3. call __ocfs2_mark_extent_written. it will do:
1) check the flags of unwritten
2) do the real split work.
The whole process is packed tightly somehow. So this patch
will abstract 2 different functions so that future b-tree
operation can work with it.
1. __ocfs2_split_extent will accept path and split_rec and do
the real split work.
2. ocfs2_change_extent_flag will accept a new flag and initialize
path and split_rec.
So now ocfs2_mark_extent_written will do:
1. check the parameters.
2. call ocfs2_change_extent_flag.
1) initalize the left_path and split_rec.
2) check whether the new flags conflict with the old one.
3) call __ocfs2_split_extent to do the split.
Signed-off-by: Tao Ma <tao.ma at oracle.com>
---
fs/ocfs2/alloc.c | 142 ++++++++++++++++++++++++++++++++----------------------
1 files changed, 85 insertions(+), 57 deletions(-)
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index d79a62e..912f29c 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -4904,10 +4904,9 @@ out:
}
/*
- * Mark part or all of the extent record at split_index in the leaf
- * pointed to by path as written. This removes the unwritten
- * extent flag.
- *
+ * Split part or all of the extent record at split_index in the leaf
+ * pointed to by path. Merge with the contiguous extent record if needed.
+
* Care is taken to handle contiguousness so as to not grow the tree.
*
* meta_ac is not strictly necessary - we only truly need it if growth
@@ -4923,13 +4922,13 @@ out:
* have been brought into cache (and pinned via the journal), so the
* extra overhead is not expressed in terms of disk reads.
*/
-static int __ocfs2_mark_extent_written(handle_t *handle,
- struct ocfs2_extent_tree *et,
- struct ocfs2_path *path,
- int split_index,
- struct ocfs2_extent_rec *split_rec,
- struct ocfs2_alloc_context *meta_ac,
- struct ocfs2_cached_dealloc_ctxt *dealloc)
+static int __ocfs2_split_extent(handle_t *handle,
+ struct ocfs2_extent_tree *et,
+ struct ocfs2_path *path,
+ int split_index,
+ struct ocfs2_extent_rec *split_rec,
+ struct ocfs2_alloc_context *meta_ac,
+ struct ocfs2_cached_dealloc_ctxt *dealloc)
{
int ret = 0;
struct ocfs2_extent_list *el = path_leaf_el(path);
@@ -4939,12 +4938,6 @@ static int __ocfs2_mark_extent_written(handle_t *handle,
struct ocfs2_extent_list *rightmost_el;
struct ocfs2_alloc_context local_meta_ac;
- if (!(rec->e_flags & OCFS2_EXT_UNWRITTEN)) {
- ret = -EIO;
- mlog_errno(ret);
- goto out;
- }
-
if (le32_to_cpu(rec->e_cpos) > le32_to_cpu(split_rec->e_cpos) ||
((le32_to_cpu(rec->e_cpos) + le16_to_cpu(rec->e_leaf_clusters)) <
(le32_to_cpu(split_rec->e_cpos) + le16_to_cpu(split_rec->e_leaf_clusters)))) {
@@ -5024,43 +5017,20 @@ out:
return ret;
}
-/*
- * Mark the already-existing extent at cpos as written for len clusters.
- *
- * If the existing extent is larger than the request, initiate a
- * split. An attempt will be made at merging with adjacent extents.
- *
- * The caller is responsible for passing down meta_ac if we'll need it.
- */
-int ocfs2_mark_extent_written(struct inode *inode,
- struct ocfs2_extent_tree *et,
- handle_t *handle, u32 cpos, u32 len, u32 phys,
- struct ocfs2_alloc_context *meta_ac,
- struct ocfs2_cached_dealloc_ctxt *dealloc)
+static int ocfs2_change_extent_flag(handle_t *handle,
+ struct ocfs2_extent_tree *et,
+ u32 cpos, u32 len, u32 phys,
+ struct ocfs2_alloc_context *meta_ac,
+ struct ocfs2_cached_dealloc_ctxt *dealloc,
+ int new_flags, int clear_flags)
{
int ret, index;
- u64 start_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys);
+ struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
+ u64 start_blkno = ocfs2_clusters_to_blocks(sb, phys);
struct ocfs2_extent_rec split_rec;
struct ocfs2_path *left_path = NULL;
struct ocfs2_extent_list *el;
-
- mlog(0, "Inode %lu cpos %u, len %u, phys %u (%llu)\n",
- inode->i_ino, cpos, len, phys, (unsigned long long)start_blkno);
-
- if (!ocfs2_writes_unwritten_extents(OCFS2_SB(inode->i_sb))) {
- ocfs2_error(inode->i_sb, "Inode %llu has unwritten extents "
- "that are being written to, but the feature bit "
- "is not set in the super block.",
- (unsigned long long)OCFS2_I(inode)->ip_blkno);
- ret = -EROFS;
- goto out;
- }
-
- /*
- * XXX: This should be fixed up so that we just re-insert the
- * next extent records.
- */
- ocfs2_et_extent_map_truncate(et, 0);
+ struct ocfs2_extent_rec *rec;
left_path = ocfs2_new_path_from_et(et);
if (!left_path) {
@@ -5078,30 +5048,88 @@ int ocfs2_mark_extent_written(struct inode *inode,
index = ocfs2_search_extent_list(el, cpos);
if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
- ocfs2_error(inode->i_sb,
- "Inode %llu has an extent at cpos %u which can no "
+ ocfs2_error(sb,
+ "Owner %llu has an extent at cpos %u which can no "
"longer be found.\n",
- (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
+ (unsigned long long)
+ ocfs2_metadata_cache_owner(et->et_ci), cpos);
ret = -EROFS;
goto out;
}
+ rec = &el->l_recs[index];
+ if ((new_flags && (rec->e_flags & new_flags)) ||
+ (clear_flags && !(rec->e_flags & clear_flags))) {
+ ret = -EIO;
+ mlog_errno(ret);
+ goto out;
+ }
+
memset(&split_rec, 0, sizeof(struct ocfs2_extent_rec));
split_rec.e_cpos = cpu_to_le32(cpos);
split_rec.e_leaf_clusters = cpu_to_le16(len);
split_rec.e_blkno = cpu_to_le64(start_blkno);
- split_rec.e_flags = path_leaf_el(left_path)->l_recs[index].e_flags;
- split_rec.e_flags &= ~OCFS2_EXT_UNWRITTEN;
+ split_rec.e_flags = rec->e_flags;
+ if (new_flags)
+ split_rec.e_flags |= new_flags;
+ else
+ split_rec.e_flags &= ~clear_flags;
- ret = __ocfs2_mark_extent_written(handle, et, left_path,
- index, &split_rec, meta_ac,
- dealloc);
+ ret = __ocfs2_split_extent(handle, et, left_path,
+ index, &split_rec, meta_ac,
+ dealloc);
if (ret)
mlog_errno(ret);
out:
ocfs2_free_path(left_path);
return ret;
+
+}
+
+/*
+ * Mark the already-existing extent at cpos as written for len clusters.
+ * This removes the unwritten extent flag.
+ *
+ * If the existing extent is larger than the request, initiate a
+ * split. An attempt will be made at merging with adjacent extents.
+ *
+ * The caller is responsible for passing down meta_ac if we'll need it.
+ */
+int ocfs2_mark_extent_written(struct inode *inode,
+ struct ocfs2_extent_tree *et,
+ handle_t *handle, u32 cpos, u32 len, u32 phys,
+ struct ocfs2_alloc_context *meta_ac,
+ struct ocfs2_cached_dealloc_ctxt *dealloc)
+{
+ int ret;
+
+ mlog(0, "Inode %lu cpos %u, len %u, phys clusters %u\n",
+ inode->i_ino, cpos, len, phys);
+
+ if (!ocfs2_writes_unwritten_extents(OCFS2_SB(inode->i_sb))) {
+ ocfs2_error(inode->i_sb, "Inode %llu has unwritten extents "
+ "that are being written to, but the feature bit "
+ "is not set in the super block.",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ ret = -EROFS;
+ goto out;
+ }
+
+ /*
+ * XXX: This should be fixed up so that we just re-insert the
+ * next extent records.
+ */
+ ocfs2_et_extent_map_truncate(et, 0);
+
+ ret = ocfs2_change_extent_flag(handle, et, cpos,
+ len, phys, meta_ac, dealloc,
+ 0, OCFS2_EXT_UNWRITTEN);
+ if (ret)
+ mlog_errno(ret);
+
+out:
+ return ret;
}
static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
--
1.6.2.rc2.16.gf474c
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