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authorJeff Layton <jeff.layton@primarydata.com>2015-04-03 09:04:03 -0400
committerJeff Layton <jeff.layton@primarydata.com>2015-04-03 09:04:03 -0400
commit5c1c669a1b2435e071d566b6db1a8e6b26542ba1 (patch)
tree512cf17f4056133293b863e38d81097f921037e0 /fs/locks.c
parent663d5af750b8c025d0dfea2cf2a4b4a78cafa3a7 (diff)
downloadlwn-5c1c669a1b2435e071d566b6db1a8e6b26542ba1.tar.gz
lwn-5c1c669a1b2435e071d566b6db1a8e6b26542ba1.zip
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>
Diffstat (limited to 'fs/locks.c')
-rw-r--r--fs/locks.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/fs/locks.c b/fs/locks.c
index 36cf93f165a8..54a79883a7f9 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -203,11 +203,11 @@ static struct kmem_cache *flctx_cache __read_mostly;
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 @@ static int flock_lock_file(struct file *filp, struct file_lock *request)
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 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
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 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
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;