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>

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 4ade2b2..c200d33 100644 (file)
--- 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;
 }