ocfs2: Make ocfs2_extent_tree get/put instead of alloc.

Rather than allocating a struct ocfs2_extent_tree, just put it on the
stack.  Fill it with ocfs2_get_extent_tree() and drop it with
ocfs2_put_extent_tree().  Now the callers don't have to ENOMEM, yet
still safely ref the root_bh.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 36 insertions, 81 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 4ade2b259e6d..c200d3321689 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -223,22 +223,17 @@ static struct ocfs2_extent_tree_operations ocfs2_xattr_tree_et_ops = {
         .eo_sanity_check        = ocfs2_xattr_tree_sanity_check,
 };
 
-static struct ocfs2_extent_tree*
-         ocfs2_new_extent_tree(struct inode *inode,
-                               struct buffer_head *bh,
-                               enum ocfs2_extent_tree_type et_type,
-                               void *private)
+static void ocfs2_get_extent_tree(struct ocfs2_extent_tree *et,
+                                  struct inode *inode,
+                                  struct buffer_head *bh,
+                                  enum ocfs2_extent_tree_type et_type,
+                                  void *private)
 {
-        struct ocfs2_extent_tree *et;
-
-        et = kzalloc(sizeof(*et), GFP_NOFS);
-        if (!et)
-                return NULL;
-
         et->et_type = et_type;
         get_bh(bh);
         et->et_root_bh = bh;
         et->et_private = private;
+        et->et_max_leaf_clusters = 0;
 
         if (et_type == OCFS2_DINODE_EXTENT) {
                 et->et_root_el =
@@ -257,16 +252,11 @@ static struct ocfs2_extent_tree*
                 et->et_max_leaf_clusters = ocfs2_clusters_for_bytes(inode->i_sb,
                                                 OCFS2_MAX_XATTR_TREE_LEAF_SIZE);
         }
-
-        return et;
 }
 
-static void ocfs2_free_extent_tree(struct ocfs2_extent_tree *et)
+static void ocfs2_put_extent_tree(struct ocfs2_extent_tree *et)
 {
-        if (et) {
-                brelse(et->et_root_bh);
-                kfree(et);
-        }
+        brelse(et->et_root_bh);
 }
 
 static inline void ocfs2_et_set_last_eb_blk(struct ocfs2_extent_tree *et,
@@ -4430,22 +4420,15 @@ int ocfs2_dinode_insert_extent(struct ocfs2_super *osb,
                                struct ocfs2_alloc_context *meta_ac)
 {
         int status;
-        struct ocfs2_extent_tree *et = NULL;
-
-        et = ocfs2_new_extent_tree(inode, root_bh, OCFS2_DINODE_EXTENT, NULL);
-        if (!et) {
-                status = -ENOMEM;
-                mlog_errno(status);
-                goto bail;
-        }
+        struct ocfs2_extent_tree et;
 
+        ocfs2_get_extent_tree(&et, inode, root_bh, OCFS2_DINODE_EXTENT,
+                              NULL);
         status = ocfs2_insert_extent(osb, handle, inode, root_bh,
                                      cpos, start_blk, new_clusters,
-                                     flags, meta_ac, et);
+                                     flags, meta_ac, &et);
+        ocfs2_put_extent_tree(&et);
 
-        if (et)
-                ocfs2_free_extent_tree(et);
-bail:
         return status;
 }
 
@@ -4461,23 +4444,15 @@ int ocfs2_xattr_value_insert_extent(struct ocfs2_super *osb,
                                     void *private)
 {
         int status;
-        struct ocfs2_extent_tree *et = NULL;
-
-        et = ocfs2_new_extent_tree(inode, root_bh,
-                                   OCFS2_XATTR_VALUE_EXTENT, private);
-        if (!et) {
-                status = -ENOMEM;
-                mlog_errno(status);
-                goto bail;
-        }
+        struct ocfs2_extent_tree et;
 
+        ocfs2_get_extent_tree(&et, inode, root_bh,
+                              OCFS2_XATTR_VALUE_EXTENT, private);
         status = ocfs2_insert_extent(osb, handle, inode, root_bh,
                                      cpos, start_blk, new_clusters,
-                                     flags, meta_ac, et);
+                                     flags, meta_ac, &et);
+        ocfs2_put_extent_tree(&et);
 
-        if (et)
-                ocfs2_free_extent_tree(et);
-bail:
         return status;
 }
 
@@ -4492,23 +4467,15 @@ int ocfs2_xattr_tree_insert_extent(struct ocfs2_super *osb,
                                    struct ocfs2_alloc_context *meta_ac)
 {
         int status;
-        struct ocfs2_extent_tree *et = NULL;
-
-        et = ocfs2_new_extent_tree(inode, root_bh, OCFS2_XATTR_TREE_EXTENT,
-                                   NULL);
-        if (!et) {
-                status = -ENOMEM;
-                mlog_errno(status);
-                goto bail;
-        }
+        struct ocfs2_extent_tree et;
 
+        ocfs2_get_extent_tree(&et, inode, root_bh, OCFS2_XATTR_TREE_EXTENT,
+                              NULL);
         status = ocfs2_insert_extent(osb, handle, inode, root_bh,
                                      cpos, start_blk, new_clusters,
-                                     flags, meta_ac, et);
+                                     flags, meta_ac, &et);
+        ocfs2_put_extent_tree(&et);
 
-        if (et)
-                ocfs2_free_extent_tree(et);
-bail:
         return status;
 }
 
@@ -4897,11 +4864,13 @@ int ocfs2_mark_extent_written(struct inode *inode, struct buffer_head *root_bh,
         struct ocfs2_extent_rec split_rec;
         struct ocfs2_path *left_path = NULL;
         struct ocfs2_extent_list *el;
-        struct ocfs2_extent_tree *et = NULL;
+        struct ocfs2_extent_tree et;
 
         mlog(0, "Inode %lu cpos %u, len %u, phys %u (%llu)\n",
              inode->i_ino, cpos, len, phys, (unsigned long long)start_blkno);
 
+        ocfs2_get_extent_tree(&et, inode, root_bh, et_type, private);
+
         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 "
@@ -4911,13 +4880,6 @@ int ocfs2_mark_extent_written(struct inode *inode, struct buffer_head *root_bh,
                 goto out;
         }
 
-        et = ocfs2_new_extent_tree(inode, root_bh, et_type, private);
-        if (!et) {
-                ret = -ENOMEM;
-                mlog_errno(ret);
-                goto out;
-        }
-
         /*
          * XXX: This should be fixed up so that we just re-insert the
          * next extent records.
@@ -4925,7 +4887,7 @@ int ocfs2_mark_extent_written(struct inode *inode, struct buffer_head *root_bh,
         if (et_type == OCFS2_DINODE_EXTENT)
                 ocfs2_extent_map_trunc(inode, 0);
 
-        left_path = ocfs2_new_path(et->et_root_bh, et->et_root_el);
+        left_path = ocfs2_new_path(et.et_root_bh, et.et_root_el);
         if (!left_path) {
                 ret = -ENOMEM;
                 mlog_errno(ret);
@@ -4956,7 +4918,7 @@ int ocfs2_mark_extent_written(struct inode *inode, struct buffer_head *root_bh,
         split_rec.e_flags = path_leaf_el(left_path)->l_recs[index].e_flags;
         split_rec.e_flags &= ~OCFS2_EXT_UNWRITTEN;
 
-        ret = __ocfs2_mark_extent_written(inode, et, handle, left_path,
+        ret = __ocfs2_mark_extent_written(inode, &et, handle, left_path,
                                           index, &split_rec, meta_ac,
                                           dealloc);
         if (ret)
@@ -4964,8 +4926,7 @@ int ocfs2_mark_extent_written(struct inode *inode, struct buffer_head *root_bh,
 
 out:
         ocfs2_free_path(left_path);
-        if (et)
-                ocfs2_free_extent_tree(et);
+        ocfs2_put_extent_tree(&et);
         return ret;
 }
 
@@ -5207,18 +5168,13 @@ int ocfs2_remove_extent(struct inode *inode, struct buffer_head *root_bh,
         struct ocfs2_extent_rec *rec;
         struct ocfs2_extent_list *el;
         struct ocfs2_path *path = NULL;
-        struct ocfs2_extent_tree *et = NULL;
+        struct ocfs2_extent_tree et;
 
-        et = ocfs2_new_extent_tree(inode, root_bh, et_type, private);
-        if (!et) {
-                ret = -ENOMEM;
-                mlog_errno(ret);
-                goto out;
-        }
+        ocfs2_get_extent_tree(&et, inode, root_bh, et_type, private);
 
         ocfs2_extent_map_trunc(inode, 0);
 
-        path = ocfs2_new_path(et->et_root_bh, et->et_root_el);
+        path = ocfs2_new_path(et.et_root_bh, et.et_root_el);
         if (!path) {
                 ret = -ENOMEM;
                 mlog_errno(ret);
@@ -5271,13 +5227,13 @@ int ocfs2_remove_extent(struct inode *inode, struct buffer_head *root_bh,
 
         if (le32_to_cpu(rec->e_cpos) == cpos || rec_range == trunc_range) {
                 ret = ocfs2_truncate_rec(inode, handle, path, index, dealloc,
-                                         cpos, len, et);
+                                         cpos, len, &et);
                 if (ret) {
                         mlog_errno(ret);
                         goto out;
                 }
         } else {
-                ret = ocfs2_split_tree(inode, et, handle, path, index,
+                ret = ocfs2_split_tree(inode, &et, handle, path, index,
                                        trunc_range, meta_ac);
                 if (ret) {
                         mlog_errno(ret);
@@ -5326,7 +5282,7 @@ int ocfs2_remove_extent(struct inode *inode, struct buffer_head *root_bh,
                 }
 
                 ret = ocfs2_truncate_rec(inode, handle, path, index, dealloc,
-                                         cpos, len, et);
+                                         cpos, len, &et);
                 if (ret) {
                         mlog_errno(ret);
                         goto out;
@@ -5335,8 +5291,7 @@ int ocfs2_remove_extent(struct inode *inode, struct buffer_head *root_bh,
 
 out:
         ocfs2_free_path(path);
-        if (et)
-                ocfs2_free_extent_tree(et);
+        ocfs2_put_extent_tree(&et);
         return ret;
 }