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authorLinus Torvalds <torvalds@linux-foundation.org>2013-08-07 13:01:30 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-08-07 13:01:30 -0700
commitb7bc9e7d808ba55729bd263b0210cda36965be32 (patch)
tree3854bc709c38f75fbc4b9e90bdedba5202482dc1 /fs
parent8ef9c292ac7bf91fc0367746cf5db264adddced9 (diff)
parent9457158bbc0ee04ecef76862d73eecd8076e9c7b (diff)
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Merge tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt: "Oleg Nesterov has been working hard in closing all the holes that can lead to race conditions between deleting an event and accessing an event debugfs file. This included a fix to the debugfs system (acked by Greg Kroah-Hartman). We think that all the holes have been patched and hopefully we don't find more. I haven't marked all of them for stable because I need to examine them more to figure out how far back some of the changes need to go. Along the way, some other fixes have been made. Alexander Z Lam fixed some logic where the wrong buffer was being modifed. Andrew Vagin found a possible corruption for machines that actually allocate cpumask, as a reference to one was being zeroed out by mistake. Dhaval Giani found a bad prototype when tracing is not configured. And I not only had some changes to help Oleg, but also finally fixed a long standing bug that Dave Jones and others have been hitting, where a module unload and reload can cause the function tracing accounting to get screwed up" * tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix reset of time stamps during trace_clock changes tracing: Make TRACE_ITER_STOP_ON_FREE stop the correct buffer tracing: Fix trace_dump_stack() proto when CONFIG_TRACING is not set tracing: Fix fields of struct trace_iterator that are zeroed by mistake tracing/uprobes: Fail to unregister if probe event files are in use tracing/kprobes: Fail to unregister if probe event files are in use tracing: Add comment to describe special break case in probe_remove_event_call() tracing: trace_remove_event_call() should fail if call/file is in use debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs) ftrace: Check module functions being traced on reload ftrace: Consolidate some duplicate code for updating ftrace ops tracing: Change remove_event_file_dir() to clear "d_subdirs"->i_private tracing: Introduce remove_event_file_dir() tracing: Change f_start() to take event_mutex and verify i_private != NULL tracing: Change event_filter_read/write to verify i_private != NULL tracing: Change event_enable/disable_read() to verify i_private != NULL tracing: Turn event/id->i_private into call->event.type
Diffstat (limited to 'fs')
-rw-r--r--fs/debugfs/inode.c69
1 files changed, 22 insertions, 47 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 4888cb3fdef7..c7c83ff0f752 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -533,8 +533,7 @@ EXPORT_SYMBOL_GPL(debugfs_remove);
*/
void debugfs_remove_recursive(struct dentry *dentry)
{
- struct dentry *child;
- struct dentry *parent;
+ struct dentry *child, *next, *parent;
if (IS_ERR_OR_NULL(dentry))
return;
@@ -544,61 +543,37 @@ void debugfs_remove_recursive(struct dentry *dentry)
return;
parent = dentry;
+ down:
mutex_lock(&parent->d_inode->i_mutex);
+ list_for_each_entry_safe(child, next, &parent->d_subdirs, d_u.d_child) {
+ if (!debugfs_positive(child))
+ continue;
- while (1) {
- /*
- * When all dentries under "parent" has been removed,
- * walk up the tree until we reach our starting point.
- */
- if (list_empty(&parent->d_subdirs)) {
- mutex_unlock(&parent->d_inode->i_mutex);
- if (parent == dentry)
- break;
- parent = parent->d_parent;
- mutex_lock(&parent->d_inode->i_mutex);
- }
- child = list_entry(parent->d_subdirs.next, struct dentry,
- d_u.d_child);
- next_sibling:
-
- /*
- * If "child" isn't empty, walk down the tree and
- * remove all its descendants first.
- */
+ /* perhaps simple_empty(child) makes more sense */
if (!list_empty(&child->d_subdirs)) {
mutex_unlock(&parent->d_inode->i_mutex);
parent = child;
- mutex_lock(&parent->d_inode->i_mutex);
- continue;
+ goto down;
}
- __debugfs_remove(child, parent);
- if (parent->d_subdirs.next == &child->d_u.d_child) {
- /*
- * Try the next sibling.
- */
- if (child->d_u.d_child.next != &parent->d_subdirs) {
- child = list_entry(child->d_u.d_child.next,
- struct dentry,
- d_u.d_child);
- goto next_sibling;
- }
-
- /*
- * Avoid infinite loop if we fail to remove
- * one dentry.
- */
- mutex_unlock(&parent->d_inode->i_mutex);
- break;
- }
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+ up:
+ if (!__debugfs_remove(child, parent))
+ simple_release_fs(&debugfs_mount, &debugfs_mount_count);
}
- parent = dentry->d_parent;
+ mutex_unlock(&parent->d_inode->i_mutex);
+ child = parent;
+ parent = parent->d_parent;
mutex_lock(&parent->d_inode->i_mutex);
- __debugfs_remove(dentry, parent);
+
+ if (child != dentry) {
+ next = list_entry(child->d_u.d_child.next, struct dentry,
+ d_u.d_child);
+ goto up;
+ }
+
+ if (!__debugfs_remove(child, parent))
+ simple_release_fs(&debugfs_mount, &debugfs_mount_count);
mutex_unlock(&parent->d_inode->i_mutex);
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
}
EXPORT_SYMBOL_GPL(debugfs_remove_recursive);