Commit 5c1c669a authored by Jeff Layton's avatar Jeff Layton
Browse files

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: default avatarJeff Layton <jlayton@primarydata.com>
parent 663d5af7

fs/locks.c

+12 −8
Original line number Diff line number Diff line
@@ -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)

	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;

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