locks: add a dedicated spinlock to protect i_flctx lists
We can now add a dedicated spinlock without expanding struct inode.
Change to using that to protect the various i_flctx lists.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/locks.c b/fs/locks.c
index d46e705..a268d95 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -161,7 +161,7 @@
* The global file_lock_list is only used for displaying /proc/locks, so we
* keep a list on each CPU, with each list protected by its own spinlock via
* the file_lock_lglock. Note that alterations to the list also require that
- * the relevant i_lock is held.
+ * the relevant flc_lock is held.
*/
DEFINE_STATIC_LGLOCK(file_lock_lglock);
static DEFINE_PER_CPU(struct hlist_head, file_lock_list);
@@ -189,13 +189,13 @@
* 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 i_lock as well. In certain cases, when reading the fields
+ * we often hold the flc_lock as well. In certain cases, when reading the fields
* protected by this lock, we can skip acquiring it iff we already hold the
- * i_lock.
+ * flc_lock.
*
* In particular, adding an entry to the fl_block list requires that you hold
- * both the i_lock and the blocked_lock_lock (acquired in that order). Deleting
- * an entry from the list however only requires the file_lock_lock.
+ * both the flc_lock and the blocked_lock_lock (acquired in that order).
+ * Deleting an entry from the list however only requires the file_lock_lock.
*/
static DEFINE_SPINLOCK(blocked_lock_lock);
@@ -214,6 +214,7 @@
if (!new)
goto out;
+ spin_lock_init(&new->flc_lock);
INIT_LIST_HEAD(&new->flc_flock);
INIT_LIST_HEAD(&new->flc_posix);
INIT_LIST_HEAD(&new->flc_lease);
@@ -557,7 +558,7 @@
return fl1->fl_owner == fl2->fl_owner;
}
-/* Must be called with the i_lock held! */
+/* Must be called with the flc_lock held! */
static void locks_insert_global_locks(struct file_lock *fl)
{
lg_local_lock(&file_lock_lglock);
@@ -566,12 +567,12 @@
lg_local_unlock(&file_lock_lglock);
}
-/* Must be called with the i_lock held! */
+/* Must be called with the flc_lock held! */
static void locks_delete_global_locks(struct file_lock *fl)
{
/*
* Avoid taking lock if already unhashed. This is safe since this check
- * is done while holding the i_lock, and new insertions into the list
+ * is done while holding the flc_lock, and new insertions into the list
* also require that it be held.
*/
if (hlist_unhashed(&fl->fl_link))
@@ -623,10 +624,10 @@
* the order they blocked. The documentation doesn't require this but
* it seems like the reasonable thing to do.
*
- * Must be called with both the i_lock and blocked_lock_lock held. The fl_block
- * list itself is protected by the blocked_lock_lock, but by ensuring that the
- * i_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.
+ * 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.
*/
static void __locks_insert_block(struct file_lock *blocker,
struct file_lock *waiter)
@@ -638,7 +639,7 @@
locks_insert_global_blocked(waiter);
}
-/* Must be called with i_lock held. */
+/* Must be called with flc_lock held. */
static void locks_insert_block(struct file_lock *blocker,
struct file_lock *waiter)
{
@@ -650,15 +651,15 @@
/*
* Wake up processes blocked waiting for blocker.
*
- * Must be called with the inode->i_lock held!
+ * Must be called with the inode->flc_lock held!
*/
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 i_lock, and
- * the i_lock is always held here. Note that removal from the fl_block
- * list does not require the i_lock, so we must recheck list_empty()
+ * 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.
*/
if (list_empty(&blocker->fl_block))
@@ -768,7 +769,7 @@
return;
}
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
list_for_each_entry(cfl, &ctx->flc_posix, fl_list) {
if (posix_locks_conflict(fl, cfl)) {
locks_copy_conflock(fl, cfl);
@@ -779,7 +780,7 @@
}
fl->fl_type = F_UNLCK;
out:
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
return;
}
EXPORT_SYMBOL(posix_test_lock);
@@ -880,7 +881,7 @@
return -ENOMEM;
}
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
if (request->fl_flags & FL_ACCESS)
goto find_conflict;
@@ -905,9 +906,9 @@
* give it the opportunity to lock the file.
*/
if (found) {
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
cond_resched();
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
}
find_conflict:
@@ -929,7 +930,7 @@
error = 0;
out:
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
if (new_fl)
locks_free_lock(new_fl);
locks_dispose_list(&dispose);
@@ -965,7 +966,7 @@
new_fl2 = locks_alloc_lock();
}
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
/*
* New lock request. Walk all POSIX locks and look for conflicts. If
* there are any, either return error or put the request on the
@@ -1136,7 +1137,7 @@
locks_wake_up_blocks(left);
}
out:
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
/*
* Free any unused locks.
*/
@@ -1218,7 +1219,7 @@
/*
* Search the lock list for this inode for any POSIX locks.
*/
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
ret = 0;
list_for_each_entry(fl, &ctx->flc_posix, fl_list) {
if (fl->fl_owner != current->files &&
@@ -1227,7 +1228,7 @@
break;
}
}
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
return ret;
}
@@ -1346,7 +1347,7 @@
struct file_lock_context *ctx = inode->i_flctx;
struct file_lock *fl, *tmp;
- lockdep_assert_held(&inode->i_lock);
+ lockdep_assert_held(&ctx->flc_lock);
list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list) {
trace_time_out_leases(inode, fl);
@@ -1370,7 +1371,7 @@
struct file_lock_context *ctx = inode->i_flctx;
struct file_lock *fl;
- lockdep_assert_held(&inode->i_lock);
+ lockdep_assert_held(&ctx->flc_lock);
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
if (leases_conflict(fl, breaker))
@@ -1413,7 +1414,7 @@
return error;
}
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
@@ -1463,11 +1464,11 @@
break_time++;
locks_insert_block(fl, new_fl);
trace_break_lease_block(inode, new_fl);
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
locks_dispose_list(&dispose);
error = wait_event_interruptible_timeout(new_fl->fl_wait,
!new_fl->fl_next, break_time);
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
trace_break_lease_unblock(inode, new_fl);
locks_delete_block(new_fl);
if (error >= 0) {
@@ -1482,7 +1483,7 @@
error = 0;
}
out:
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
locks_dispose_list(&dispose);
locks_free_lock(new_fl);
return error;
@@ -1506,14 +1507,14 @@
struct file_lock *fl;
if (ctx && !list_empty_careful(&ctx->flc_lease)) {
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
if (!list_empty(&ctx->flc_lease)) {
fl = list_first_entry(&ctx->flc_lease,
struct file_lock, fl_list);
if (fl->fl_type == F_WRLCK)
has_lease = true;
}
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
}
if (has_lease)
@@ -1556,7 +1557,7 @@
LIST_HEAD(dispose);
if (ctx && !list_empty_careful(&ctx->flc_lease)) {
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
time_out_leases(file_inode(filp), &dispose);
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
if (fl->fl_file != filp)
@@ -1564,7 +1565,7 @@
type = target_leasetype(fl);
break;
}
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
locks_dispose_list(&dispose);
}
return type;
@@ -1632,7 +1633,7 @@
return -EINVAL;
}
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
error = check_conflicting_open(dentry, arg);
if (error)
@@ -1699,7 +1700,7 @@
if (lease->fl_lmops->lm_setup)
lease->fl_lmops->lm_setup(lease, priv);
out:
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
locks_dispose_list(&dispose);
if (is_deleg)
mutex_unlock(&inode->i_mutex);
@@ -1722,7 +1723,7 @@
return error;
}
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
if (fl->fl_file == filp) {
victim = fl;
@@ -1732,7 +1733,7 @@
trace_generic_delete_lease(inode, fl);
if (victim)
error = fl->fl_lmops->lm_change(&victim, F_UNLCK, &dispose);
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
locks_dispose_list(&dispose);
return error;
}
@@ -2423,10 +2424,10 @@
if (!ctx || list_empty(&ctx->flc_lease))
return;
- spin_lock(&inode->i_lock);
+ spin_lock(&ctx->flc_lock);
list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
lease_modify(&fl, F_UNLCK, &dispose);
- spin_unlock(&inode->i_lock);
+ spin_unlock(&ctx->flc_lock);
locks_dispose_list(&dispose);
}