[PATCH v2 14/17] locks: __break_lease cleanup in preparation of allowing direct removal of leases

Jeff Layton
2014-09-04T12:39:19Z

Eliminate an unneeded "flock" variable. We can use "fl" as a loop cursor
everywhere. Add a any_leases_conflict helper function as well to
consolidate a bit of code.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
---
fs/locks.c | 49 +++++++++++++++++++++++++------------------------
1 file changed, 25 insertions(+), 24 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index 011812490c92..246ba53650f7 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1351,6 +1351,20 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
return locks_conflict(breaker, lease);
}

+static bool
+any_leases_conflict(struct inode *inode, struct file_lock *breaker)
+{
+ struct file_lock *fl;
+
+ lockdep_assert_held(&inode->i_lock);
+
+ for (fl = inode->i_flock ; fl && IS_LEASE(fl); fl = fl->fl_next) {
+ if (leases_conflict(fl, breaker))
+ return true;
+ }
+ return false;
+}
+
/**
* __break_lease - revoke all outstanding leases on file
* @inode: the inode of the file to return
@@ -1367,10 +1381,9 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
{
int error = 0;
- struct file_lock *new_fl, *flock;
+ struct file_lock *new_fl;
struct file_lock *fl;
unsigned long break_time;
- bool lease_conflict = false;
int want_write = (mode & O_ACCMODE) != O_RDONLY;
LIST_HEAD(dispose);

@@ -1383,17 +1396,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)

time_out_leases(inode, &dispose);

- flock = inode->i_flock;
- if ((flock == NULL) || !IS_LEASE(flock))
- goto out;
-
- for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
- if (leases_conflict(fl, new_fl)) {
- lease_conflict = true;
- break;
- }
- }
- if (!lease_conflict)
+ if (!any_leases_conflict(inode, new_fl))
goto out;

break_time = 0;
@@ -1403,7 +1406,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
break_time++; /* so that 0 means no break time */
}

- for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
+ for (fl = inode->i_flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
if (!leases_conflict(fl, new_fl))
continue;
if (want_write) {
@@ -1412,7 +1415,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
fl->fl_flags |= FL_UNLOCK_PENDING;
fl->fl_break_time = break_time;
} else {
- if (lease_breaking(flock))
+ if (lease_breaking(inode->i_flock))
continue;
fl->fl_flags |= FL_DOWNGRADE_PENDING;
fl->fl_downgrade_time = break_time;
@@ -1427,12 +1430,12 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
}

restart:
- break_time = flock->fl_break_time;
+ break_time = inode->i_flock->fl_break_time;
if (break_time != 0)
break_time -= jiffies;
if (break_time == 0)
break_time++;
- locks_insert_block(flock, new_fl);
+ locks_insert_block(inode->i_flock, new_fl);
trace_break_lease_block(inode, new_fl);
spin_unlock(&inode->i_lock);
locks_dispose_list(&dispose);
@@ -1442,17 +1445,15 @@ restart:
trace_break_lease_unblock(inode, new_fl);
locks_delete_block(new_fl);
if (error >= 0) {
- if (error == 0)
- time_out_leases(inode, &dispose);
/*
* Wait for the next conflicting lease that has not been
* broken yet
*/
- for (flock = inode->i_flock; flock && IS_LEASE(flock);
- flock = flock->fl_next) {
- if (leases_conflict(new_fl, flock))
- goto restart;
- }
+ if (error == 0)
+ time_out_leases(inode, &dispose);
+ if (any_leases_conflict(inode, new_fl))
+ goto restart;
+
error = 0;
}

--
1.9.3