locks: comment cleanups and clarifications (1cb36012) · Commits · e / devices / android_kernel_oneplus_sm7250

fs/locks.c

+13 −8

Original line number	Original line	Diff line number	Diff line
	@@ -518,9 +518,10 @@ static void locks_insert_block(struct file_lock *blocker,
	list_add(&waiter->fl_link, &blocked_list);		list_add(&waiter->fl_link, &blocked_list);
	}		}

	/* Wake up processes blocked waiting for blocker.		/*
	* If told to wait then schedule the processes until the block list		* Wake up processes blocked waiting for blocker.
	* is empty, otherwise empty the block list ourselves.		*
			* Must be called with the file_lock_lock held!
	*/		*/
	static void locks_wake_up_blocks(struct file_lock *blocker)		static void locks_wake_up_blocks(struct file_lock *blocker)
	{		{
	@@ -806,6 +807,11 @@ static int __posix_lock_file(struct inode inode, struct file_lock request, str
	}		}

	lock_flocks();		lock_flocks();
			/*
			* New lock request. Walk all POSIX locks and look for conflicts. If
			* there are any, either return error or put the request on the
			* blocker's list of waiters and the global blocked_list.
			*/
	if (request->fl_type != F_UNLCK) {		if (request->fl_type != F_UNLCK) {
	for_each_lock(inode, before) {		for_each_lock(inode, before) {
	fl = *before;		fl = *before;
	@@ -930,10 +936,9 @@ static int __posix_lock_file(struct inode inode, struct file_lock request, str
	}		}

	/*		/*
	* The above code only modifies existing locks in case of		* The above code only modifies existing locks in case of merging or
	* merging or replacing. If new lock(s) need to be inserted		* replacing. If new lock(s) need to be inserted all modifications are
	* all modifications are done bellow this, so it's safe yet to		* done below this, so it's safe yet to bail out.
	* bail out.
	*/		*/
	error = -ENOLCK; /* "no luck" */		error = -ENOLCK; /* "no luck" */
	if (right && left == right && !new_fl2)		if (right && left == right && !new_fl2)

include/linux/fs.h

+18 −0

Original line number	Original line	Diff line number	Diff line
	@@ -926,6 +926,24 @@ int locks_in_grace(struct net *);
	/* that will die - we need it for nfs_lock_info */		/* that will die - we need it for nfs_lock_info */
	#include <linux/nfs_fs_i.h>		#include <linux/nfs_fs_i.h>

			/*
			* struct file_lock represents a generic "file lock". It's used to represent
			* POSIX byte range locks, BSD (flock) locks, and leases. It's important to
			* note that the same struct is used to represent both a request for a lock and
			* the lock itself, but the same object is never used for both.
			*
			* FIXME: should we create a separate "struct lock_request" to help distinguish
			* these two uses?
			*
			* The i_flock list is ordered by:
			*
			* 1) lock type -- FL_LEASEs first, then FL_FLOCK, and finally FL_POSIX
			* 2) lock owner
			* 3) lock range start
			* 4) lock range end
			*
			* Obviously, the last two criteria only matter for POSIX locks.
			*/
	struct file_lock {		struct file_lock {
	struct file_lock fl_next; / singly linked list for this inode */		struct file_lock fl_next; / singly linked list for this inode */
	struct list_head fl_link; /* doubly linked list of all locks */		struct list_head fl_link; /* doubly linked list of all locks */