From 9370bb92b2d16684ee45cf24e879c93c509162da Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 19 Dec 2024 01:47:39 +0000
Subject: [PATCH] add wifi6 8852be driver
---
kernel/fs/locks.c | 601 +++++++++++++++++++++++++++++++++++++----------------
1 files changed, 415 insertions(+), 186 deletions(-)
diff --git a/kernel/fs/locks.c b/kernel/fs/locks.c
index 28270e7..cbb5701 100644
--- a/kernel/fs/locks.c
+++ b/kernel/fs/locks.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/locks.c
*
@@ -11,11 +12,11 @@
*
* Miscellaneous edits, and a total rewrite of posix_lock_file() code.
* Kai Petzke (wpp@marie.physik.tu-berlin.de), 1994
- *
+ *
* Converted file_lock_table to a linked list from an array, which eliminates
* the limits on how many active file locks are open.
* Chad Page (pageone@netcom.com), November 27, 1994
- *
+ *
* Removed dependency on file descriptors. dup()'ed file descriptors now
* get the same locks as the original file descriptors, and a close() on
* any file descriptor removes ALL the locks on the file for the current
@@ -41,7 +42,7 @@
* with a file pointer (filp). As a result they can be shared by a parent
* process and its children after a fork(). They are removed when the last
* file descriptor referring to the file pointer is closed (unless explicitly
- * unlocked).
+ * unlocked).
*
* FL_FLOCK locks never deadlock, an existing lock is always removed before
* upgrading from shared to exclusive (or vice versa). When this happens
@@ -50,7 +51,7 @@
* Andy Walker (andy@lysaker.kvaerner.no), June 09, 1995
*
* Removed some race conditions in flock_lock_file(), marked other possible
- * races. Just grep for FIXME to see them.
+ * races. Just grep for FIXME to see them.
* Dmitry Gorodchanin (pgmdsg@ibi.com), February 09, 1996.
*
* Addressed Dmitry's concerns. Deadlock checking no longer recursive.
@@ -60,7 +61,7 @@
*
* Initial implementation of mandatory locks. SunOS turned out to be
* a rotten model, so I implemented the "obvious" semantics.
- * See 'Documentation/filesystems/mandatory-locking.txt' for details.
+ * See 'Documentation/filesystems/mandatory-locking.rst' for details.
* Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996.
*
* Don't allow mandatory locks on mmap()'ed files. Added simple functions to
@@ -112,6 +113,46 @@
* Leases and LOCK_MAND
* Matthew Wilcox <willy@debian.org>, June, 2000.
* Stephen Rothwell <sfr@canb.auug.org.au>, June, 2000.
+ *
+ * Locking conflicts and dependencies:
+ * If multiple threads attempt to lock the same byte (or flock the same file)
+ * only one can be granted the lock, and other must wait their turn.
+ * The first lock has been "applied" or "granted", the others are "waiting"
+ * and are "blocked" by the "applied" lock..
+ *
+ * Waiting and applied locks are all kept in trees whose properties are:
+ *
+ * - the root of a tree may be an applied or waiting lock.
+ * - every other node in the tree is a waiting lock that
+ * conflicts with every ancestor of that node.
+ *
+ * Every such tree begins life as a waiting singleton which obviously
+ * satisfies the above properties.
+ *
+ * The only ways we modify trees preserve these properties:
+ *
+ * 1. We may add a new leaf node, but only after first verifying that it
+ * conflicts with all of its ancestors.
+ * 2. We may remove the root of a tree, creating a new singleton
+ * tree from the root and N new trees rooted in the immediate
+ * children.
+ * 3. If the root of a tree is not currently an applied lock, we may
+ * apply it (if possible).
+ * 4. We may upgrade the root of the tree (either extend its range,
+ * or upgrade its entire range from read to write).
+ *
+ * When an applied lock is modified in a way that reduces or downgrades any
+ * part of its range, we remove all its children (2 above). This particularly
+ * happens when a lock is unlocked.
+ *
+ * For each of those child trees we "wake up" the thread which is
+ * waiting for the lock so it can continue handling as follows: if the
+ * root of the tree applies, we do so (3). If it doesn't, it must
+ * conflict with some applied lock. We remove (wake up) all of its children
+ * (2), and add it is a new leaf to the tree rooted in the applied
+ * lock (1). We then repeat the process recursively with those
+ * children.
+ *
*/
#include <linux/capability.h>
@@ -171,6 +212,7 @@
static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list);
DEFINE_STATIC_PERCPU_RWSEM(file_rwsem);
+
/*
* The blocked_hash is used to find POSIX lock loops for deadlock detection.
* It is protected by blocked_lock_lock.
@@ -189,9 +231,9 @@
* 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 +335,8 @@
{
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);
}
@@ -311,6 +354,12 @@
void locks_release_private(struct file_lock *fl)
{
+ BUG_ON(waitqueue_active(&fl->fl_wait));
+ BUG_ON(!list_empty(&fl->fl_list));
+ BUG_ON(!list_empty(&fl->fl_blocked_requests));
+ BUG_ON(!list_empty(&fl->fl_blocked_member));
+ BUG_ON(!hlist_unhashed(&fl->fl_link));
+
if (fl->fl_ops) {
if (fl->fl_ops->fl_release_private)
fl->fl_ops->fl_release_private(fl);
@@ -330,11 +379,6 @@
/* Free a lock which is not in use. */
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(!hlist_unhashed(&fl->fl_link));
-
locks_release_private(fl);
kmem_cache_free(filelock_cache, fl);
}
@@ -357,7 +401,6 @@
memset(fl, 0, sizeof(struct file_lock));
locks_init_lock_heads(fl);
}
-
EXPORT_SYMBOL(locks_init_lock);
/*
@@ -397,8 +440,25 @@
fl->fl_ops->fl_copy_lock(new, fl);
}
}
-
EXPORT_SYMBOL(locks_copy_lock);
+
+static void locks_move_blocks(struct file_lock *new, struct file_lock *fl)
+{
+ struct file_lock *f;
+
+ /*
+ * As ctx->flc_lock is held, new requests cannot be added to
+ * ->fl_blocked_requests, so we don't need a lock to check if it
+ * is empty.
+ */
+ if (list_empty(&fl->fl_blocked_requests))
+ return;
+ spin_lock(&blocked_lock_lock);
+ list_splice_init(&fl->fl_blocked_requests, &new->fl_blocked_requests);
+ list_for_each_entry(f, &new->fl_blocked_requests, fl_blocked_member)
+ f->fl_blocker = new;
+ spin_unlock(&blocked_lock_lock);
+}
static inline int flock_translate_cmd(int cmd) {
if (cmd & LOCK_MAND)
@@ -416,17 +476,20 @@
/* Fill in a file_lock structure with an appropriate FLOCK lock. */
static struct file_lock *
-flock_make_lock(struct file *filp, unsigned int cmd)
+flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl)
{
- struct file_lock *fl;
int type = flock_translate_cmd(cmd);
if (type < 0)
return ERR_PTR(type);
-
- fl = locks_alloc_lock();
- if (fl == NULL)
- return ERR_PTR(-ENOMEM);
+
+ if (fl == NULL) {
+ fl = locks_alloc_lock();
+ if (fl == NULL)
+ return ERR_PTR(-ENOMEM);
+ } else {
+ locks_init_lock(fl);
+ }
fl->fl_file = filp;
fl->fl_owner = filp;
@@ -434,7 +497,7 @@
fl->fl_flags = FL_FLOCK;
fl->fl_type = type;
fl->fl_end = OFFSET_MAX;
-
+
return fl;
}
@@ -596,9 +659,6 @@
*/
static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
{
- if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner)
- return fl2->fl_lmops == fl1->fl_lmops &&
- fl1->fl_lmops->lm_compare_owner(fl1, fl2);
return fl1->fl_owner == fl2->fl_owner;
}
@@ -639,8 +699,6 @@
static unsigned long
posix_owner_key(struct file_lock *fl)
{
- if (fl->fl_lmops && fl->fl_lmops->lm_owner_key)
- return fl->fl_lmops->lm_owner_key(fl);
return (unsigned long)fl->fl_owner;
}
@@ -666,16 +724,81 @@
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);
}
-static void locks_delete_block(struct file_lock *waiter)
+static void __locks_wake_up_blocks(struct file_lock *blocker)
{
- spin_lock(&blocked_lock_lock);
- __locks_delete_block(waiter);
- spin_unlock(&blocked_lock_lock);
+ while (!list_empty(&blocker->fl_blocked_requests)) {
+ struct file_lock *waiter;
+
+ 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);
+ else
+ wake_up(&waiter->fl_wait);
+
+ /*
+ * The setting of fl_blocker to NULL marks the "done"
+ * point in deleting a block. Paired with acquire at the top
+ * of locks_delete_block().
+ */
+ smp_store_release(&waiter->fl_blocker, NULL);
+ }
}
+
+/**
+ * locks_delete_lock - stop waiting for a file lock
+ * @waiter: the lock which was waiting
+ *
+ * lockd/nfsd need to disconnect the lock while working on it.
+ */
+int locks_delete_block(struct file_lock *waiter)
+{
+ int status = -ENOENT;
+
+ /*
+ * If fl_blocker is NULL, it won't be set again as this thread "owns"
+ * the lock and is the only one that might try to claim the lock.
+ *
+ * We use acquire/release to manage fl_blocker so that we can
+ * optimize away taking the blocked_lock_lock in many cases.
+ *
+ * The smp_load_acquire guarantees two things:
+ *
+ * 1/ that fl_blocked_requests can be tested locklessly. If something
+ * was recently added to that list it must have been in a locked region
+ * *before* the locked region when fl_blocker was set to NULL.
+ *
+ * 2/ that no other thread is accessing 'waiter', so it is safe to free
+ * it. __locks_wake_up_blocks is careful not to touch waiter after
+ * fl_blocker is released.
+ *
+ * If a lockless check of fl_blocker shows it to be NULL, we know that
+ * no new locks can be inserted into its fl_blocked_requests list, and
+ * can avoid doing anything further if the list is empty.
+ */
+ if (!smp_load_acquire(&waiter->fl_blocker) &&
+ list_empty(&waiter->fl_blocked_requests))
+ return status;
+
+ spin_lock(&blocked_lock_lock);
+ if (waiter->fl_blocker)
+ status = 0;
+ __locks_wake_up_blocks(waiter);
+ __locks_delete_block(waiter);
+
+ /*
+ * The setting of fl_blocker to NULL marks the "done" point in deleting
+ * a block. Paired with acquire at the top of this function.
+ */
+ smp_store_release(&waiter->fl_blocker, NULL);
+ spin_unlock(&blocked_lock_lock);
+ return status;
+}
+EXPORT_SYMBOL(locks_delete_block);
/* Insert waiter into blocker's block list.
* We use a circular list so that processes can be easily woken up in
@@ -683,26 +806,49 @@
* 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.
+ *
+ * Rather than just adding to the list, we check for conflicts with any existing
+ * waiters, and add beneath any waiter that blocks the new waiter.
+ * Thus wakeups don't happen until needed.
*/
static void __locks_insert_block(struct file_lock *blocker,
- struct file_lock *waiter)
+ struct file_lock *waiter,
+ bool conflict(struct file_lock *,
+ struct file_lock *))
{
- BUG_ON(!list_empty(&waiter->fl_block));
- waiter->fl_next = blocker;
- list_add_tail(&waiter->fl_block, &blocker->fl_block);
+ struct file_lock *fl;
+ BUG_ON(!list_empty(&waiter->fl_blocked_member));
+
+new_blocker:
+ list_for_each_entry(fl, &blocker->fl_blocked_requests, fl_blocked_member)
+ if (conflict(fl, waiter)) {
+ blocker = fl;
+ goto new_blocker;
+ }
+ 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);
+
+ /* The requests in waiter->fl_blocked are known to conflict with
+ * waiter, but might not conflict with blocker, or the requests
+ * and lock which block it. So they all need to be woken.
+ */
+ __locks_wake_up_blocks(waiter);
}
/* Must be called with flc_lock held. */
static void locks_insert_block(struct file_lock *blocker,
- struct file_lock *waiter)
+ struct file_lock *waiter,
+ bool conflict(struct file_lock *,
+ struct file_lock *))
{
spin_lock(&blocked_lock_lock);
- __locks_insert_block(blocker, waiter);
+ __locks_insert_block(blocker, waiter, conflict);
spin_unlock(&blocked_lock_lock);
}
@@ -716,25 +862,15 @@
/*
* 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)) {
- struct file_lock *waiter;
-
- waiter = list_first_entry(&blocker->fl_block,
- struct file_lock, fl_block);
- __locks_delete_block(waiter);
- if (waiter->fl_lmops && waiter->fl_lmops->lm_notify)
- waiter->fl_lmops->lm_notify(waiter);
- else
- wake_up(&waiter->fl_wait);
- }
+ __locks_wake_up_blocks(blocker);
spin_unlock(&blocked_lock_lock);
}
@@ -766,47 +902,50 @@
/* Determine if lock sys_fl blocks lock caller_fl. Common functionality
* checks for shared/exclusive status of overlapping locks.
*/
-static int locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl)
+static bool locks_conflict(struct file_lock *caller_fl,
+ struct file_lock *sys_fl)
{
if (sys_fl->fl_type == F_WRLCK)
- return 1;
+ return true;
if (caller_fl->fl_type == F_WRLCK)
- return 1;
- return 0;
+ return true;
+ return false;
}
/* Determine if lock sys_fl blocks lock caller_fl. POSIX specific
* checking before calling the locks_conflict().
*/
-static int posix_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl)
+static bool posix_locks_conflict(struct file_lock *caller_fl,
+ struct file_lock *sys_fl)
{
/* POSIX locks owned by the same process do not conflict with
* each other.
*/
if (posix_same_owner(caller_fl, sys_fl))
- return (0);
+ return false;
/* Check whether they overlap */
if (!locks_overlap(caller_fl, sys_fl))
- return 0;
+ return false;
- return (locks_conflict(caller_fl, sys_fl));
+ return locks_conflict(caller_fl, sys_fl);
}
/* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific
* checking before calling the locks_conflict().
*/
-static int flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl)
+static bool flock_locks_conflict(struct file_lock *caller_fl,
+ struct file_lock *sys_fl)
{
/* FLOCK locks referring to the same filp do not conflict with
* each other.
*/
if (caller_fl->fl_file == sys_fl->fl_file)
- return (0);
+ return false;
if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND))
- return 0;
+ return false;
- return (locks_conflict(caller_fl, sys_fl));
+ return locks_conflict(caller_fl, sys_fl);
}
void
@@ -877,8 +1016,11 @@
struct file_lock *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;
+ if (posix_same_owner(fl, block_fl)) {
+ while (fl->fl_blocker)
+ fl = fl->fl_blocker;
+ return fl;
+ }
}
return NULL;
}
@@ -936,7 +1078,7 @@
return -ENOMEM;
}
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
if (request->fl_flags & FL_ACCESS)
goto find_conflict;
@@ -965,19 +1107,20 @@
if (!(request->fl_flags & FL_SLEEP))
goto out;
error = FILE_LOCK_DEFERRED;
- locks_insert_block(fl, request);
+ locks_insert_block(fl, request, flock_locks_conflict);
goto out;
}
if (request->fl_flags & FL_ACCESS)
goto out;
locks_copy_lock(new_fl, request);
+ locks_move_blocks(new_fl, request);
locks_insert_lock_ctx(new_fl, &ctx->flc_flock);
new_fl = NULL;
error = 0;
out:
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
if (new_fl)
locks_free_lock(new_fl);
locks_dispose_list(&dispose);
@@ -1015,7 +1158,7 @@
new_fl2 = locks_alloc_lock();
}
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
/*
* New lock request. Walk all POSIX locks and look for conflicts. If
@@ -1037,14 +1180,20 @@
*/
error = -EDEADLK;
spin_lock(&blocked_lock_lock);
+ /*
+ * Ensure that we don't find any locks blocked on this
+ * request during deadlock detection.
+ */
+ __locks_wake_up_blocks(request);
if (likely(!posix_locks_deadlock(request, fl))) {
error = FILE_LOCK_DEFERRED;
- __locks_insert_block(fl, request);
+ __locks_insert_block(fl, request,
+ posix_locks_conflict);
}
spin_unlock(&blocked_lock_lock);
goto out;
- }
- }
+ }
+ }
/* If we're just looking for a conflict, we're done. */
error = 0;
@@ -1133,6 +1282,7 @@
if (!new_fl)
goto out;
locks_copy_lock(new_fl, request);
+ locks_move_blocks(new_fl, request);
request = new_fl;
new_fl = NULL;
locks_insert_lock_ctx(request, &fl->fl_list);
@@ -1164,6 +1314,7 @@
goto out;
}
locks_copy_lock(new_fl, request);
+ locks_move_blocks(new_fl, request);
locks_insert_lock_ctx(new_fl, &fl->fl_list);
fl = new_fl;
new_fl = NULL;
@@ -1187,7 +1338,8 @@
}
out:
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
+ trace_posix_lock_inode(inode, request, error);
/*
* Free any unused locks.
*/
@@ -1196,7 +1348,6 @@
if (new_fl2)
locks_free_lock(new_fl2);
locks_dispose_list(&dispose);
- trace_posix_lock_inode(inode, request, error);
return error;
}
@@ -1237,13 +1388,12 @@
error = posix_lock_inode(inode, fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
- error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
- if (!error)
- continue;
-
- locks_delete_block(fl);
- break;
+ error = wait_event_interruptible(fl->fl_wait,
+ list_empty(&fl->fl_blocked_member));
+ if (error)
+ break;
}
+ locks_delete_block(fl);
return error;
}
@@ -1324,7 +1474,8 @@
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,
+ list_empty(&fl.fl_blocked_member));
if (!error) {
/*
* If we've been sleeping someone might have
@@ -1334,13 +1485,12 @@
continue;
}
- locks_delete_block(&fl);
break;
}
+ locks_delete_block(&fl);
return error;
}
-
EXPORT_SYMBOL(locks_mandatory_area);
#endif /* CONFIG_MANDATORY_FILE_LOCKING */
@@ -1349,7 +1499,7 @@
switch (arg) {
case F_UNLCK:
fl->fl_flags &= ~FL_UNLOCK_PENDING;
- /* fall through: */
+ fallthrough;
case F_RDLCK:
fl->fl_flags &= ~FL_DOWNGRADE_PENDING;
}
@@ -1406,11 +1556,24 @@
static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
{
- if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT))
+ bool rc;
+
+ if (lease->fl_lmops->lm_breaker_owns_lease
+ && lease->fl_lmops->lm_breaker_owns_lease(lease))
return false;
- if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE))
- return false;
- return locks_conflict(breaker, lease);
+ if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) {
+ rc = false;
+ goto trace;
+ }
+ if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE)) {
+ rc = false;
+ goto trace;
+ }
+
+ rc = locks_conflict(breaker, lease);
+trace:
+ trace_leases_conflict(rc, lease, breaker);
+ return rc;
}
static bool
@@ -1459,10 +1622,10 @@
ctx = smp_load_acquire(&inode->i_flctx);
if (!ctx) {
WARN_ON_ONCE(1);
- return error;
+ goto free_lock;
}
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
@@ -1511,16 +1674,17 @@
break_time -= jiffies;
if (break_time == 0)
break_time++;
- locks_insert_block(fl, new_fl);
+ locks_insert_block(fl, new_fl, leases_conflict);
trace_break_lease_block(inode, new_fl);
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
locks_dispose_list(&dispose);
error = wait_event_interruptible_timeout(new_fl->fl_wait,
- !new_fl->fl_next, break_time);
+ list_empty(&new_fl->fl_blocked_member),
+ break_time);
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
trace_break_lease_unblock(inode, new_fl);
locks_delete_block(new_fl);
@@ -1537,12 +1701,12 @@
}
out:
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
locks_dispose_list(&dispose);
+free_lock:
locks_free_lock(new_fl);
return error;
}
-
EXPORT_SYMBOL(__break_lease);
/**
@@ -1573,7 +1737,6 @@
if (has_lease)
*time = current_time(inode);
}
-
EXPORT_SYMBOL(lease_get_mtime);
/**
@@ -1609,7 +1772,7 @@
ctx = smp_load_acquire(&inode->i_flctx);
if (ctx && !list_empty_careful(&ctx->flc_lease)) {
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
@@ -1619,7 +1782,7 @@
break;
}
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
locks_dispose_list(&dispose);
}
@@ -1627,10 +1790,10 @@
}
/**
- * check_conflicting_open - see if the given dentry points to a file that has
- * an existing open that would conflict with the
- * desired lease.
- * @dentry: dentry to check
+ * check_conflicting_open - see if the given file points to an inode that has
+ * an existing open that would conflict with the
+ * desired lease.
+ * @filp: file to check
* @arg: type of lease that we're trying to acquire
* @flags: current lock flags
*
@@ -1638,30 +1801,42 @@
* conflict with the lease we're trying to set.
*/
static int
-check_conflicting_open(const struct dentry *dentry, const long arg, int flags)
+check_conflicting_open(struct file *filp, const long arg, int flags)
{
- int ret = 0;
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = locks_inode(filp);
+ int self_wcount = 0, self_rcount = 0;
if (flags & FL_LAYOUT)
return 0;
- if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
+ if (arg == F_RDLCK)
+ return inode_is_open_for_write(inode) ? -EAGAIN : 0;
+ else if (arg != F_WRLCK)
+ return 0;
+
+ /*
+ * Make sure that only read/write count is from lease requestor.
+ * Note that this will result in denying write leases when i_writecount
+ * is negative, which is what we want. (We shouldn't grant write leases
+ * on files open for execution.)
+ */
+ if (filp->f_mode & FMODE_WRITE)
+ self_wcount = 1;
+ else if (filp->f_mode & FMODE_READ)
+ self_rcount = 1;
+
+ if (atomic_read(&inode->i_writecount) != self_wcount ||
+ atomic_read(&inode->i_readcount) != self_rcount)
return -EAGAIN;
- if ((arg == F_WRLCK) && ((d_count(dentry) > 1) ||
- (atomic_read(&inode->i_count) > 1)))
- ret = -EAGAIN;
-
- return ret;
+ return 0;
}
static int
generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv)
{
struct file_lock *fl, *my_fl = NULL, *lease;
- struct dentry *dentry = filp->f_path.dentry;
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = locks_inode(filp);
struct file_lock_context *ctx;
bool is_deleg = (*flp)->fl_flags & FL_DELEG;
int error;
@@ -1693,10 +1868,10 @@
return -EINVAL;
}
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
- error = check_conflicting_open(dentry, arg, lease->fl_flags);
+ error = check_conflicting_open(filp, arg, lease->fl_flags);
if (error)
goto out;
@@ -1753,7 +1928,7 @@
* precedes these checks.
*/
smp_mb();
- error = check_conflicting_open(dentry, arg, lease->fl_flags);
+ error = check_conflicting_open(filp, arg, lease->fl_flags);
if (error) {
locks_unlink_lock_ctx(lease);
goto out;
@@ -1764,7 +1939,7 @@
lease->fl_lmops->lm_setup(lease, priv);
out:
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
locks_dispose_list(&dispose);
if (is_deleg)
inode_unlock(inode);
@@ -1787,7 +1962,7 @@
return error;
}
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
if (fl->fl_file == filp &&
@@ -1800,7 +1975,7 @@
if (victim)
error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose);
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
locks_dispose_list(&dispose);
return error;
}
@@ -1847,13 +2022,71 @@
}
EXPORT_SYMBOL(generic_setlease);
+#if IS_ENABLED(CONFIG_SRCU)
+/*
+ * Kernel subsystems can register to be notified on any attempt to set
+ * a new lease with the lease_notifier_chain. This is used by (e.g.) nfsd
+ * to close files that it may have cached when there is an attempt to set a
+ * conflicting lease.
+ */
+static struct srcu_notifier_head lease_notifier_chain;
+
+static inline void
+lease_notifier_chain_init(void)
+{
+ srcu_init_notifier_head(&lease_notifier_chain);
+}
+
+static inline void
+setlease_notifier(long arg, struct file_lock *lease)
+{
+ if (arg != F_UNLCK)
+ srcu_notifier_call_chain(&lease_notifier_chain, arg, lease);
+}
+
+int lease_register_notifier(struct notifier_block *nb)
+{
+ return srcu_notifier_chain_register(&lease_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(lease_register_notifier);
+
+void lease_unregister_notifier(struct notifier_block *nb)
+{
+ srcu_notifier_chain_unregister(&lease_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(lease_unregister_notifier);
+
+#else /* !IS_ENABLED(CONFIG_SRCU) */
+static inline void
+lease_notifier_chain_init(void)
+{
+}
+
+static inline void
+setlease_notifier(long arg, struct file_lock *lease)
+{
+}
+
+int lease_register_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(lease_register_notifier);
+
+void lease_unregister_notifier(struct notifier_block *nb)
+{
+}
+EXPORT_SYMBOL_GPL(lease_unregister_notifier);
+
+#endif /* IS_ENABLED(CONFIG_SRCU) */
+
/**
* vfs_setlease - sets a lease on an open file
* @filp: file pointer
* @arg: type of lease to obtain
* @lease: file_lock to use when adding a lease
* @priv: private info for lm_setup when adding a lease (may be
- * NULL if lm_setup doesn't require it)
+ * NULL if lm_setup doesn't require it)
*
* Call this to establish a lease on the file. The "lease" argument is not
* used for F_UNLCK requests and may be NULL. For commands that set or alter
@@ -1867,6 +2100,8 @@
int
vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
{
+ if (lease)
+ setlease_notifier(arg, *lease);
if (filp->f_op->setlease)
return filp->f_op->setlease(filp, arg, lease, priv);
else
@@ -1931,13 +2166,12 @@
error = flock_lock_inode(inode, fl);
if (error != FILE_LOCK_DEFERRED)
break;
- error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
- if (!error)
- continue;
-
- locks_delete_block(fl);
- break;
+ error = wait_event_interruptible(fl->fl_wait,
+ list_empty(&fl->fl_blocked_member));
+ if (error)
+ break;
}
+ locks_delete_block(fl);
return error;
}
@@ -2001,7 +2235,7 @@
!(f.file->f_mode & (FMODE_READ|FMODE_WRITE)))
goto out_putf;
- lock = flock_make_lock(f.file, cmd);
+ lock = flock_make_lock(f.file, cmd, NULL);
if (IS_ERR(lock)) {
error = PTR_ERR(lock);
goto out_putf;
@@ -2143,7 +2377,7 @@
error = vfs_test_lock(filp, fl);
if (error)
goto out;
-
+
flock->l_type = fl->fl_type;
if (fl->fl_type != F_UNLCK) {
error = posix_lock_to_flock(flock, fl);
@@ -2210,13 +2444,12 @@
error = vfs_lock_file(filp, cmd, fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
- error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
- if (!error)
- continue;
-
- locks_delete_block(fl);
- break;
+ error = wait_event_interruptible(fl->fl_wait,
+ list_empty(&fl->fl_blocked_member));
+ if (error)
+ break;
}
+ locks_delete_block(fl);
return error;
}
@@ -2289,7 +2522,7 @@
cmd = F_SETLKW;
file_lock->fl_flags |= FL_OFDLCK;
file_lock->fl_owner = filp;
- /* Fallthrough */
+ fallthrough;
case F_SETLKW:
file_lock->fl_flags |= FL_SLEEP;
}
@@ -2420,7 +2653,7 @@
cmd = F_SETLKW64;
file_lock->fl_flags |= FL_OFDLCK;
file_lock->fl_owner = filp;
- /* Fallthrough */
+ fallthrough;
case F_SETLKW64:
file_lock->fl_flags |= FL_SLEEP;
}
@@ -2476,6 +2709,7 @@
if (!ctx || list_empty(&ctx->flc_posix))
return;
+ locks_init_lock(&lock);
lock.fl_type = F_UNLCK;
lock.fl_flags = FL_POSIX | FL_CLOSE;
lock.fl_start = 0;
@@ -2492,25 +2726,20 @@
lock.fl_ops->fl_release_private(&lock);
trace_locks_remove_posix(inode, &lock, error);
}
-
EXPORT_SYMBOL(locks_remove_posix);
/* The i_flctx must be valid when calling into here */
static void
locks_remove_flock(struct file *filp, struct file_lock_context *flctx)
{
- struct file_lock fl = {
- .fl_owner = filp,
- .fl_pid = current->tgid,
- .fl_file = filp,
- .fl_flags = FL_FLOCK | FL_CLOSE,
- .fl_type = F_UNLCK,
- .fl_end = OFFSET_MAX,
- };
+ struct file_lock fl;
struct inode *inode = locks_inode(filp);
if (list_empty(&flctx->flc_flock))
return;
+
+ flock_make_lock(filp, LOCK_UN, &fl);
+ fl.fl_flags |= FL_CLOSE;
if (filp->f_op->flock)
filp->f_op->flock(filp, F_SETLKW, &fl);
@@ -2531,13 +2760,13 @@
if (list_empty(&ctx->flc_lease))
return;
- percpu_down_read_preempt_disable(&file_rwsem);
+ percpu_down_read(&file_rwsem);
spin_lock(&ctx->flc_lock);
list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
if (filp == fl->fl_file)
lease_modify(fl, F_UNLCK, &dispose);
spin_unlock(&ctx->flc_lock);
- percpu_up_read_preempt_enable(&file_rwsem);
+ percpu_up_read(&file_rwsem);
locks_dispose_list(&dispose);
}
@@ -2570,27 +2799,6 @@
}
/**
- * posix_unblock_lock - stop waiting for a file lock
- * @waiter: the lock which was waiting
- *
- * lockd needs to block waiting for locks.
- */
-int
-posix_unblock_lock(struct file_lock *waiter)
-{
- int status = 0;
-
- spin_lock(&blocked_lock_lock);
- if (waiter->fl_next)
- __locks_delete_block(waiter);
- else
- status = -ENOENT;
- spin_unlock(&blocked_lock_lock);
- return status;
-}
-EXPORT_SYMBOL(posix_unblock_lock);
-
-/**
* vfs_cancel_lock - file byte range unblock lock
* @filp: The file to apply the unblock to
* @fl: The lock to be unblocked
@@ -2603,8 +2811,30 @@
return filp->f_op->lock(filp, F_CANCELLK, fl);
return 0;
}
-
EXPORT_SYMBOL_GPL(vfs_cancel_lock);
+
+/**
+ * vfs_inode_has_locks - are any file locks held on @inode?
+ * @inode: inode to check for locks
+ *
+ * Return true if there are any FL_POSIX or FL_FLOCK locks currently
+ * set on @inode.
+ */
+bool vfs_inode_has_locks(struct inode *inode)
+{
+ struct file_lock_context *ctx;
+ bool ret;
+
+ ctx = smp_load_acquire(&inode->i_flctx);
+ if (!ctx)
+ return false;
+
+ spin_lock(&ctx->flc_lock);
+ ret = !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_flock);
+ spin_unlock(&ctx->flc_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vfs_inode_has_locks);
#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
@@ -2620,7 +2850,7 @@
{
struct inode *inode = NULL;
unsigned int fl_pid;
- struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info;
+ struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb);
fl_pid = locks_translate_pid(fl, proc_pidns);
/*
@@ -2671,10 +2901,10 @@
? (fl->fl_type & LOCK_WRITE) ? "RW " : "READ "
: (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE ");
} else {
- seq_printf(f, "%s ",
- (lease_breaking(fl))
- ? (fl->fl_type == F_UNLCK) ? "UNLCK" : "READ "
- : (fl->fl_type == F_WRLCK) ? "WRITE" : "READ ");
+ int type = IS_LEASE(fl) ? target_leasetype(fl) : fl->fl_type;
+
+ seq_printf(f, "%s ", (type == F_WRLCK) ? "WRITE" :
+ (type == F_RDLCK) ? "READ" : "UNLCK");
}
if (inode) {
/* userspace relies on this representation of dev_t */
@@ -2698,7 +2928,7 @@
{
struct locks_iterator *iter = f->private;
struct file_lock *fl, *bfl;
- struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info;
+ struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb);
fl = hlist_entry(v, struct file_lock, fl_link);
@@ -2707,7 +2937,7 @@
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;
@@ -2803,7 +3033,6 @@
filelock_cache = kmem_cache_create("file_lock_cache",
sizeof(struct file_lock), 0, SLAB_PANIC, NULL);
-
for_each_possible_cpu(i) {
struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i);
@@ -2811,7 +3040,7 @@
INIT_HLIST_HEAD(&fll->hlist);
}
+ lease_notifier_chain_init();
return 0;
}
-
core_initcall(filelock_init);
--
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