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authorNeilBrown <neilb@suse.com>2018-11-30 10:04:08 +1100
committerJeff Layton <jlayton@kernel.org>2018-11-30 11:26:12 -0500
commitada5c1da8660ecae24b3e75c18ee77d79e099fee (patch)
treec1579a9a4924fa11b6fc49cc9bdb7e5f3e59aae4 /fs/locks.c
parentccda4af0f4b92f7b4c308d3acc262f4a7e3affad (diff)
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fs/locks: rename some lists and pointers.
struct file lock contains an 'fl_next' pointer which is used to point to the lock that this request is blocked waiting for. So rename it to fl_blocker. The fl_blocked list_head in an active lock is the head of a list of blocked requests. In a request it is a node in that list. These are two distinct uses, so replace with two list_heads with different names. fl_blocked_requests is the head of a list of blocked requests fl_blocked_member is a node in a member of that list. The two different list_heads are never used at the same time, but that will change in a future patch. Note that a tracepoint is changed to report fl_blocker instead of fl_next. Signed-off-by: NeilBrown <neilb@suse.com> Reviewed-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org>
Diffstat (limited to 'fs/locks.c')
-rw-r--r--fs/locks.c59
1 files changed, 31 insertions, 28 deletions
diff --git a/fs/locks.c b/fs/locks.c
index 2ecb4db8c840..c6df0c8b3d13 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -189,9 +189,9 @@ static DEFINE_HASHTABLE(blocked_hash, BLOCKED_HASH_BITS);
* This lock protects the blocked_hash. Generally, if you're accessing it, you
* want to be holding this lock.
*
- * In addition, it also protects the fl->fl_block list, and the fl->fl_next
- * pointer for file_lock structures that are acting as lock requests (in
- * contrast to those that are acting as records of acquired locks).
+ * In addition, it also protects the fl->fl_blocked_requests list, and the
+ * fl->fl_blocker pointer for file_lock structures that are acting as lock
+ * requests (in contrast to those that are acting as records of acquired locks).
*
* Note that when we acquire this lock in order to change the above fields,
* we often hold the flc_lock as well. In certain cases, when reading the fields
@@ -293,7 +293,8 @@ static void locks_init_lock_heads(struct file_lock *fl)
{
INIT_HLIST_NODE(&fl->fl_link);
INIT_LIST_HEAD(&fl->fl_list);
- INIT_LIST_HEAD(&fl->fl_block);
+ INIT_LIST_HEAD(&fl->fl_blocked_requests);
+ INIT_LIST_HEAD(&fl->fl_blocked_member);
init_waitqueue_head(&fl->fl_wait);
}
@@ -332,7 +333,8 @@ void locks_free_lock(struct file_lock *fl)
{
BUG_ON(waitqueue_active(&fl->fl_wait));
BUG_ON(!list_empty(&fl->fl_list));
- BUG_ON(!list_empty(&fl->fl_block));
+ BUG_ON(!list_empty(&fl->fl_blocked_requests));
+ BUG_ON(!list_empty(&fl->fl_blocked_member));
BUG_ON(!hlist_unhashed(&fl->fl_link));
locks_release_private(fl);
@@ -666,8 +668,8 @@ static void locks_delete_global_blocked(struct file_lock *waiter)
static void __locks_delete_block(struct file_lock *waiter)
{
locks_delete_global_blocked(waiter);
- list_del_init(&waiter->fl_block);
- waiter->fl_next = NULL;
+ list_del_init(&waiter->fl_blocked_member);
+ waiter->fl_blocker = NULL;
}
static void locks_delete_block(struct file_lock *waiter)
@@ -683,16 +685,17 @@ static void locks_delete_block(struct file_lock *waiter)
* it seems like the reasonable thing to do.
*
* Must be called with both the flc_lock and blocked_lock_lock held. The
- * fl_block list itself is protected by the blocked_lock_lock, but by ensuring
- * that the flc_lock is also held on insertions we can avoid taking the
- * blocked_lock_lock in some cases when we see that the fl_block list is empty.
+ * fl_blocked_requests list itself is protected by the blocked_lock_lock,
+ * but by ensuring that the flc_lock is also held on insertions we can avoid
+ * taking the blocked_lock_lock in some cases when we see that the
+ * fl_blocked_requests list is empty.
*/
static void __locks_insert_block(struct file_lock *blocker,
struct file_lock *waiter)
{
- BUG_ON(!list_empty(&waiter->fl_block));
- waiter->fl_next = blocker;
- list_add_tail(&waiter->fl_block, &blocker->fl_block);
+ BUG_ON(!list_empty(&waiter->fl_blocked_member));
+ waiter->fl_blocker = blocker;
+ list_add_tail(&waiter->fl_blocked_member, &blocker->fl_blocked_requests);
if (IS_POSIX(blocker) && !IS_OFDLCK(blocker))
locks_insert_global_blocked(waiter);
}
@@ -716,19 +719,19 @@ static void locks_wake_up_blocks(struct file_lock *blocker)
/*
* Avoid taking global lock if list is empty. This is safe since new
* blocked requests are only added to the list under the flc_lock, and
- * the flc_lock is always held here. Note that removal from the fl_block
- * list does not require the flc_lock, so we must recheck list_empty()
- * after acquiring the blocked_lock_lock.
+ * the flc_lock is always held here. Note that removal from the
+ * fl_blocked_requests list does not require the flc_lock, so we must
+ * recheck list_empty() after acquiring the blocked_lock_lock.
*/
- if (list_empty(&blocker->fl_block))
+ if (list_empty(&blocker->fl_blocked_requests))
return;
spin_lock(&blocked_lock_lock);
- while (!list_empty(&blocker->fl_block)) {
+ while (!list_empty(&blocker->fl_blocked_requests)) {
struct file_lock *waiter;
- waiter = list_first_entry(&blocker->fl_block,
- struct file_lock, fl_block);
+ waiter = list_first_entry(&blocker->fl_blocked_requests,
+ struct file_lock, fl_blocked_member);
__locks_delete_block(waiter);
if (waiter->fl_lmops && waiter->fl_lmops->lm_notify)
waiter->fl_lmops->lm_notify(waiter);
@@ -878,7 +881,7 @@ static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl)
hash_for_each_possible(blocked_hash, fl, fl_link, posix_owner_key(block_fl)) {
if (posix_same_owner(fl, block_fl))
- return fl->fl_next;
+ return fl->fl_blocker;
}
return NULL;
}
@@ -1237,7 +1240,7 @@ static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl)
error = posix_lock_inode(inode, fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
- error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
+ error = wait_event_interruptible(fl->fl_wait, !fl->fl_blocker);
if (!error)
continue;
@@ -1324,7 +1327,7 @@ int locks_mandatory_area(struct inode *inode, struct file *filp, loff_t start,
error = posix_lock_inode(inode, &fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
- error = wait_event_interruptible(fl.fl_wait, !fl.fl_next);
+ error = wait_event_interruptible(fl.fl_wait, !fl.fl_blocker);
if (!error) {
/*
* If we've been sleeping someone might have
@@ -1518,7 +1521,7 @@ restart:
locks_dispose_list(&dispose);
error = wait_event_interruptible_timeout(new_fl->fl_wait,
- !new_fl->fl_next, break_time);
+ !new_fl->fl_blocker, break_time);
percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
@@ -1931,7 +1934,7 @@ static int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl)
error = flock_lock_inode(inode, fl);
if (error != FILE_LOCK_DEFERRED)
break;
- error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
+ error = wait_event_interruptible(fl->fl_wait, !fl->fl_blocker);
if (!error)
continue;
@@ -2210,7 +2213,7 @@ static int do_lock_file_wait(struct file *filp, unsigned int cmd,
error = vfs_lock_file(filp, cmd, fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
- error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
+ error = wait_event_interruptible(fl->fl_wait, !fl->fl_blocker);
if (!error)
continue;
@@ -2581,7 +2584,7 @@ posix_unblock_lock(struct file_lock *waiter)
int status = 0;
spin_lock(&blocked_lock_lock);
- if (waiter->fl_next)
+ if (waiter->fl_blocker)
__locks_delete_block(waiter);
else
status = -ENOENT;
@@ -2707,7 +2710,7 @@ static int locks_show(struct seq_file *f, void *v)
lock_get_status(f, fl, iter->li_pos, "");
- list_for_each_entry(bfl, &fl->fl_block, fl_block)
+ list_for_each_entry(bfl, &fl->fl_blocked_requests, fl_blocked_member)
lock_get_status(f, bfl, iter->li_pos, " ->");
return 0;