locks: don't allocate a lock context for an F_UNLCK request
In the event that we get an F_UNLCK request on an inode that has no lock
context, there is no reason to allocate one. Change
locks_get_lock_context to take a "type" pointer and avoid allocating a
new context if it's F_UNLCK.
Then, fix the callers to return appropriately if that function returns
NULL.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
diff --git a/fs/locks.c b/fs/locks.c
index 36cf93f..54a7988 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -203,11 +203,11 @@
static struct kmem_cache *filelock_cache __read_mostly;
static struct file_lock_context *
-locks_get_lock_context(struct inode *inode)
+locks_get_lock_context(struct inode *inode, int type)
{
struct file_lock_context *new;
- if (likely(inode->i_flctx))
+ if (likely(inode->i_flctx) || type == F_UNLCK)
goto out;
new = kmem_cache_alloc(flctx_cache, GFP_KERNEL);
@@ -877,9 +877,12 @@
bool found = false;
LIST_HEAD(dispose);
- ctx = locks_get_lock_context(inode);
- if (!ctx)
- return -ENOMEM;
+ ctx = locks_get_lock_context(inode, request->fl_type);
+ if (!ctx) {
+ if (request->fl_type != F_UNLCK)
+ return -ENOMEM;
+ return (request->fl_flags & FL_EXISTS) ? -ENOENT : 0;
+ }
if (!(request->fl_flags & FL_ACCESS) && (request->fl_type != F_UNLCK)) {
new_fl = locks_alloc_lock();
@@ -945,9 +948,9 @@
bool added = false;
LIST_HEAD(dispose);
- ctx = locks_get_lock_context(inode);
+ ctx = locks_get_lock_context(inode, request->fl_type);
if (!ctx)
- return -ENOMEM;
+ return (request->fl_type == F_UNLCK) ? 0 : -ENOMEM;
/*
* We may need two file_lock structures for this operation,
@@ -1609,7 +1612,8 @@
lease = *flp;
trace_generic_add_lease(inode, lease);
- ctx = locks_get_lock_context(inode);
+ /* Note that arg is never F_UNLCK here */
+ ctx = locks_get_lock_context(inode, arg);
if (!ctx)
return -ENOMEM;