| Message ID | 1383345566-25087-6-git-send-email-cody@linux.vnet.ibm.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Fri 01-11-13 15:38:50, Cody P Schafer wrote: > Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead > of opencoding an alternate postorder iteration that modifies the tree Thanks. I've merged the patch into my tree. Honza > Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> > --- > fs/ext3/dir.c | 36 +++++------------------------------- > 1 file changed, 5 insertions(+), 31 deletions(-) > > diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c > index bafdd48..a331ad1 100644 > --- a/fs/ext3/dir.c > +++ b/fs/ext3/dir.c > @@ -309,43 +309,17 @@ struct fname { > */ > static void free_rb_tree_fname(struct rb_root *root) > { > - struct rb_node *n = root->rb_node; > - struct rb_node *parent; > - struct fname *fname; > - > - while (n) { > - /* Do the node's children first */ > - if (n->rb_left) { > - n = n->rb_left; > - continue; > - } > - if (n->rb_right) { > - n = n->rb_right; > - continue; > - } > - /* > - * The node has no children; free it, and then zero > - * out parent's link to it. Finally go to the > - * beginning of the loop and try to free the parent > - * node. > - */ > - parent = rb_parent(n); > - fname = rb_entry(n, struct fname, rb_hash); > + struct fname *fname, *next; > + > + rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) > while (fname) { > struct fname * old = fname; > fname = fname->next; > kfree (old); > } > - if (!parent) > - *root = RB_ROOT; > - else if (parent->rb_left == n) > - parent->rb_left = NULL; > - else if (parent->rb_right == n) > - parent->rb_right = NULL; > - n = parent; > - } > -} > > + *root = RB_ROOT; > +} > > static struct dir_private_info *ext3_htree_create_dir_info(struct file *filp, > loff_t pos) > -- > 1.8.4.2 >
On Mon 04-11-13 15:26:38, Jan Kara wrote: > On Fri 01-11-13 15:38:50, Cody P Schafer wrote: > > Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead > > of opencoding an alternate postorder iteration that modifies the tree > Thanks. I've merged the patch into my tree. Hum, except that the kernel oopses with this patch. And I think the problem is in rbtree_postorder_for_each_entry_safe(). How are those tests for NULL supposed to work? For example if the tree is empty, 'pos' will be NULL and you'll call rb_next_postorder(&NULL->field) which is pretty much guaranteed to oops if 'field' doesn't have offset 0 in the structure... Honza > > Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> > > --- > > fs/ext3/dir.c | 36 +++++------------------------------- > > 1 file changed, 5 insertions(+), 31 deletions(-) > > > > diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c > > index bafdd48..a331ad1 100644 > > --- a/fs/ext3/dir.c > > +++ b/fs/ext3/dir.c > > @@ -309,43 +309,17 @@ struct fname { > > */ > > static void free_rb_tree_fname(struct rb_root *root) > > { > > - struct rb_node *n = root->rb_node; > > - struct rb_node *parent; > > - struct fname *fname; > > - > > - while (n) { > > - /* Do the node's children first */ > > - if (n->rb_left) { > > - n = n->rb_left; > > - continue; > > - } > > - if (n->rb_right) { > > - n = n->rb_right; > > - continue; > > - } > > - /* > > - * The node has no children; free it, and then zero > > - * out parent's link to it. Finally go to the > > - * beginning of the loop and try to free the parent > > - * node. > > - */ > > - parent = rb_parent(n); > > - fname = rb_entry(n, struct fname, rb_hash); > > + struct fname *fname, *next; > > + > > + rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) > > while (fname) { > > struct fname * old = fname; > > fname = fname->next; > > kfree (old); > > } > > - if (!parent) > > - *root = RB_ROOT; > > - else if (parent->rb_left == n) > > - parent->rb_left = NULL; > > - else if (parent->rb_right == n) > > - parent->rb_right = NULL; > > - n = parent; > > - } > > -} > > > > + *root = RB_ROOT; > > +} > > > > static struct dir_private_info *ext3_htree_create_dir_info(struct file *filp, > > loff_t pos) > > -- > > 1.8.4.2 > > > -- > Jan Kara <jack@suse.cz> > SUSE Labs, CR
On 11/04/2013 04:45 PM, Jan Kara wrote: > On Mon 04-11-13 15:26:38, Jan Kara wrote: >> On Fri 01-11-13 15:38:50, Cody P Schafer wrote: >>> Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead >>> of opencoding an alternate postorder iteration that modifies the tree >> Thanks. I've merged the patch into my tree. > Hum, except that the kernel oopses with this patch. And I think the > problem is in rbtree_postorder_for_each_entry_safe(). How are those tests > for NULL supposed to work? For example if the tree is empty, 'pos' will be > NULL and you'll call rb_next_postorder(&NULL->field) which is pretty much > guaranteed to oops if 'field' doesn't have offset 0 in the structure... > You're absolutely right, those NULL checks are wrong when the rb_node isn't the first element. Fix incoming shortly. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c index bafdd48..a331ad1 100644 --- a/fs/ext3/dir.c +++ b/fs/ext3/dir.c @@ -309,43 +309,17 @@ struct fname { */ static void free_rb_tree_fname(struct rb_root *root) { - struct rb_node *n = root->rb_node; - struct rb_node *parent; - struct fname *fname; - - while (n) { - /* Do the node's children first */ - if (n->rb_left) { - n = n->rb_left; - continue; - } - if (n->rb_right) { - n = n->rb_right; - continue; - } - /* - * The node has no children; free it, and then zero - * out parent's link to it. Finally go to the - * beginning of the loop and try to free the parent - * node. - */ - parent = rb_parent(n); - fname = rb_entry(n, struct fname, rb_hash); + struct fname *fname, *next; + + rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) while (fname) { struct fname * old = fname; fname = fname->next; kfree (old); } - if (!parent) - *root = RB_ROOT; - else if (parent->rb_left == n) - parent->rb_left = NULL; - else if (parent->rb_right == n) - parent->rb_right = NULL; - n = parent; - } -} + *root = RB_ROOT; +} static struct dir_private_info *ext3_htree_create_dir_info(struct file *filp, loff_t pos)
Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead of opencoding an alternate postorder iteration that modifies the tree Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> --- fs/ext3/dir.c | 36 +++++------------------------------- 1 file changed, 5 insertions(+), 31 deletions(-)