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-rw-r--r--fs/locks.c142
1 files changed, 98 insertions, 44 deletions
diff --git a/fs/locks.c b/fs/locks.c
index b5152b067f37..ce93b416b490 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -127,7 +127,6 @@
#include <linux/pid_namespace.h>
#include <linux/hashtable.h>
#include <linux/percpu.h>
-#include <linux/lglock.h>
#define CREATE_TRACE_POINTS
#include <trace/events/filelock.h>
@@ -139,6 +138,11 @@
#define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG|FL_LAYOUT))
#define IS_OFDLCK(fl) (fl->fl_flags & FL_OFDLCK)
+static inline bool is_remote_lock(struct file *filp)
+{
+ return likely(!(filp->f_path.dentry->d_sb->s_flags & MS_NOREMOTELOCK));
+}
+
static bool lease_breaking(struct file_lock *fl)
{
return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING);
@@ -158,12 +162,18 @@ int lease_break_time = 45;
/*
* 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 flc_lock is held.
+ * keep a list on each CPU, with each list protected by its own spinlock.
+ * Global serialization is done using file_rwsem.
+ *
+ * Note that alterations to the list also require that the relevant flc_lock is
+ * held.
*/
-DEFINE_STATIC_LGLOCK(file_lock_lglock);
-static DEFINE_PER_CPU(struct hlist_head, file_lock_list);
+struct file_lock_list_struct {
+ spinlock_t lock;
+ struct hlist_head hlist;
+};
+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.
@@ -587,15 +597,23 @@ static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
/* Must be called with the flc_lock held! */
static void locks_insert_global_locks(struct file_lock *fl)
{
- lg_local_lock(&file_lock_lglock);
+ struct file_lock_list_struct *fll = this_cpu_ptr(&file_lock_list);
+
+ percpu_rwsem_assert_held(&file_rwsem);
+
+ spin_lock(&fll->lock);
fl->fl_link_cpu = smp_processor_id();
- hlist_add_head(&fl->fl_link, this_cpu_ptr(&file_lock_list));
- lg_local_unlock(&file_lock_lglock);
+ hlist_add_head(&fl->fl_link, &fll->hlist);
+ spin_unlock(&fll->lock);
}
/* Must be called with the flc_lock held! */
static void locks_delete_global_locks(struct file_lock *fl)
{
+ struct file_lock_list_struct *fll;
+
+ percpu_rwsem_assert_held(&file_rwsem);
+
/*
* Avoid taking lock if already unhashed. This is safe since this check
* is done while holding the flc_lock, and new insertions into the list
@@ -603,9 +621,11 @@ static void locks_delete_global_locks(struct file_lock *fl)
*/
if (hlist_unhashed(&fl->fl_link))
return;
- lg_local_lock_cpu(&file_lock_lglock, fl->fl_link_cpu);
+
+ fll = per_cpu_ptr(&file_lock_list, fl->fl_link_cpu);
+ spin_lock(&fll->lock);
hlist_del_init(&fl->fl_link);
- lg_local_unlock_cpu(&file_lock_lglock, fl->fl_link_cpu);
+ spin_unlock(&fll->lock);
}
static unsigned long
@@ -791,7 +811,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
{
struct file_lock *cfl;
struct file_lock_context *ctx;
- struct inode *inode = file_inode(filp);
+ struct inode *inode = locks_inode(filp);
ctx = smp_load_acquire(&inode->i_flctx);
if (!ctx || list_empty_careful(&ctx->flc_posix)) {
@@ -915,6 +935,7 @@ static int flock_lock_inode(struct inode *inode, struct file_lock *request)
return -ENOMEM;
}
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
if (request->fl_flags & FL_ACCESS)
goto find_conflict;
@@ -955,6 +976,7 @@ find_conflict:
out:
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
if (new_fl)
locks_free_lock(new_fl);
locks_dispose_list(&dispose);
@@ -991,6 +1013,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request,
new_fl2 = locks_alloc_lock();
}
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
/*
* New lock request. Walk all POSIX locks and look for conflicts. If
@@ -1162,6 +1185,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request,
}
out:
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
/*
* Free any unused locks.
*/
@@ -1192,7 +1216,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request,
int posix_lock_file(struct file *filp, struct file_lock *fl,
struct file_lock *conflock)
{
- return posix_lock_inode(file_inode(filp), fl, conflock);
+ return posix_lock_inode(locks_inode(filp), fl, conflock);
}
EXPORT_SYMBOL(posix_lock_file);
@@ -1232,7 +1256,7 @@ static int posix_lock_inode_wait(struct inode *inode, struct file_lock *fl)
int locks_mandatory_locked(struct file *file)
{
int ret;
- struct inode *inode = file_inode(file);
+ struct inode *inode = locks_inode(file);
struct file_lock_context *ctx;
struct file_lock *fl;
@@ -1436,6 +1460,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
return error;
}
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
@@ -1487,9 +1512,13 @@ restart:
locks_insert_block(fl, new_fl);
trace_break_lease_block(inode, new_fl);
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
+
locks_dispose_list(&dispose);
error = wait_event_interruptible_timeout(new_fl->fl_wait,
!new_fl->fl_next, break_time);
+
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
trace_break_lease_unblock(inode, new_fl);
locks_delete_block(new_fl);
@@ -1506,6 +1535,7 @@ restart:
}
out:
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
locks_dispose_list(&dispose);
locks_free_lock(new_fl);
return error;
@@ -1572,7 +1602,7 @@ EXPORT_SYMBOL(lease_get_mtime);
int fcntl_getlease(struct file *filp)
{
struct file_lock *fl;
- struct inode *inode = file_inode(filp);
+ struct inode *inode = locks_inode(filp);
struct file_lock_context *ctx;
int type = F_UNLCK;
LIST_HEAD(dispose);
@@ -1580,7 +1610,7 @@ int fcntl_getlease(struct file *filp)
ctx = smp_load_acquire(&inode->i_flctx);
if (ctx && !list_empty_careful(&ctx->flc_lease)) {
spin_lock(&ctx->flc_lock);
- time_out_leases(file_inode(filp), &dispose);
+ time_out_leases(inode, &dispose);
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
if (fl->fl_file != filp)
continue;
@@ -1613,7 +1643,8 @@ check_conflicting_open(const struct dentry *dentry, const long arg, int flags)
if (flags & FL_LAYOUT)
return 0;
- if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
+ if ((arg == F_RDLCK) &&
+ (atomic_read(&d_real_inode(dentry)->i_writecount) > 0))
return -EAGAIN;
if ((arg == F_WRLCK) && ((d_count(dentry) > 1) ||
@@ -1628,7 +1659,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
{
struct file_lock *fl, *my_fl = NULL, *lease;
struct dentry *dentry = filp->f_path.dentry;
- struct inode *inode = file_inode(filp);
+ struct inode *inode = dentry->d_inode;
struct file_lock_context *ctx;
bool is_deleg = (*flp)->fl_flags & FL_DELEG;
int error;
@@ -1660,6 +1691,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
return -EINVAL;
}
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
error = check_conflicting_open(dentry, arg, lease->fl_flags);
@@ -1730,6 +1762,7 @@ out_setup:
lease->fl_lmops->lm_setup(lease, priv);
out:
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
locks_dispose_list(&dispose);
if (is_deleg)
inode_unlock(inode);
@@ -1742,7 +1775,7 @@ static int generic_delete_lease(struct file *filp, void *owner)
{
int error = -EAGAIN;
struct file_lock *fl, *victim = NULL;
- struct inode *inode = file_inode(filp);
+ struct inode *inode = locks_inode(filp);
struct file_lock_context *ctx;
LIST_HEAD(dispose);
@@ -1752,6 +1785,7 @@ static int generic_delete_lease(struct file *filp, void *owner)
return error;
}
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
if (fl->fl_file == filp &&
@@ -1764,6 +1798,7 @@ static int generic_delete_lease(struct file *filp, void *owner)
if (victim)
error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose);
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
locks_dispose_list(&dispose);
return error;
}
@@ -1782,7 +1817,7 @@ static int generic_delete_lease(struct file *filp, void *owner)
int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
void **priv)
{
- struct inode *inode = file_inode(filp);
+ struct inode *inode = locks_inode(filp);
int error;
if ((!uid_eq(current_fsuid(), inode->i_uid)) && !capable(CAP_LEASE))
@@ -1830,7 +1865,7 @@ EXPORT_SYMBOL(generic_setlease);
int
vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
{
- if (filp->f_op->setlease)
+ if (filp->f_op->setlease && is_remote_lock(filp))
return filp->f_op->setlease(filp, arg, lease, priv);
else
return generic_setlease(filp, arg, lease, priv);
@@ -1979,7 +2014,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
if (error)
goto out_free;
- if (f.file->f_op->flock)
+ if (f.file->f_op->flock && is_remote_lock(f.file))
error = f.file->f_op->flock(f.file,
(can_sleep) ? F_SETLKW : F_SETLK,
lock);
@@ -2005,7 +2040,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
*/
int vfs_test_lock(struct file *filp, struct file_lock *fl)
{
- if (filp->f_op->lock)
+ if (filp->f_op->lock && is_remote_lock(filp))
return filp->f_op->lock(filp, F_GETLK, fl);
posix_test_lock(filp, fl);
return 0;
@@ -2129,7 +2164,7 @@ out:
*/
int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)
{
- if (filp->f_op->lock)
+ if (filp->f_op->lock && is_remote_lock(filp))
return filp->f_op->lock(filp, cmd, fl);
else
return posix_lock_file(filp, fl, conf);
@@ -2191,7 +2226,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
if (file_lock == NULL)
return -ENOLCK;
- inode = file_inode(filp);
+ inode = locks_inode(filp);
/*
* This might block, so we do it before checking the inode.
@@ -2343,7 +2378,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
if (copy_from_user(&flock, l, sizeof(flock)))
goto out;
- inode = file_inode(filp);
+ inode = locks_inode(filp);
/* Don't allow mandatory locks on files that may be memory mapped
* and shared.
@@ -2426,6 +2461,7 @@ out:
void locks_remove_posix(struct file *filp, fl_owner_t owner)
{
int error;
+ struct inode *inode = locks_inode(filp);
struct file_lock lock;
struct file_lock_context *ctx;
@@ -2434,7 +2470,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner)
* posix_lock_file(). Another process could be setting a lock on this
* file at the same time, but we wouldn't remove that lock anyway.
*/
- ctx = smp_load_acquire(&file_inode(filp)->i_flctx);
+ ctx = smp_load_acquire(&inode->i_flctx);
if (!ctx || list_empty(&ctx->flc_posix))
return;
@@ -2452,7 +2488,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner)
if (lock.fl_ops && lock.fl_ops->fl_release_private)
lock.fl_ops->fl_release_private(&lock);
- trace_locks_remove_posix(file_inode(filp), &lock, error);
+ trace_locks_remove_posix(inode, &lock, error);
}
EXPORT_SYMBOL(locks_remove_posix);
@@ -2469,12 +2505,12 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx)
.fl_type = F_UNLCK,
.fl_end = OFFSET_MAX,
};
- struct inode *inode = file_inode(filp);
+ struct inode *inode = locks_inode(filp);
if (list_empty(&flctx->flc_flock))
return;
- if (filp->f_op->flock)
+ if (filp->f_op->flock && is_remote_lock(filp))
filp->f_op->flock(filp, F_SETLKW, &fl);
else
flock_lock_inode(inode, &fl);
@@ -2508,7 +2544,7 @@ void locks_remove_file(struct file *filp)
{
struct file_lock_context *ctx;
- ctx = smp_load_acquire(&file_inode(filp)->i_flctx);
+ ctx = smp_load_acquire(&locks_inode(filp)->i_flctx);
if (!ctx)
return;
@@ -2552,7 +2588,7 @@ EXPORT_SYMBOL(posix_unblock_lock);
*/
int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
{
- if (filp->f_op->lock)
+ if (filp->f_op->lock && is_remote_lock(filp))
return filp->f_op->lock(filp, F_CANCELLK, fl);
return 0;
}
@@ -2574,13 +2610,24 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
struct inode *inode = NULL;
unsigned int fl_pid;
- if (fl->fl_nspid)
- fl_pid = pid_vnr(fl->fl_nspid);
- else
+ if (fl->fl_nspid) {
+ struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info;
+
+ /* Don't let fl_pid change based on who is reading the file */
+ fl_pid = pid_nr_ns(fl->fl_nspid, proc_pidns);
+
+ /*
+ * If there isn't a fl_pid don't display who is waiting on
+ * the lock if we are called from locks_show, or if we are
+ * called from __show_fd_info - skip lock entirely
+ */
+ if (fl_pid == 0)
+ return;
+ } else
fl_pid = fl->fl_pid;
if (fl->fl_file != NULL)
- inode = file_inode(fl->fl_file);
+ inode = locks_inode(fl->fl_file);
seq_printf(f, "%lld:%s ", id, pfx);
if (IS_POSIX(fl)) {
@@ -2648,9 +2695,13 @@ static int locks_show(struct seq_file *f, void *v)
{
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;
fl = hlist_entry(v, struct file_lock, fl_link);
+ if (fl->fl_nspid && !pid_nr_ns(fl->fl_nspid, proc_pidns))
+ return 0;
+
lock_get_status(f, fl, iter->li_pos, "");
list_for_each_entry(bfl, &fl->fl_block, fl_block)
@@ -2682,7 +2733,7 @@ static void __show_fd_locks(struct seq_file *f,
void show_fd_locks(struct seq_file *f,
struct file *filp, struct files_struct *files)
{
- struct inode *inode = file_inode(filp);
+ struct inode *inode = locks_inode(filp);
struct file_lock_context *ctx;
int id = 0;
@@ -2703,9 +2754,9 @@ static void *locks_start(struct seq_file *f, loff_t *pos)
struct locks_iterator *iter = f->private;
iter->li_pos = *pos + 1;
- lg_global_lock(&file_lock_lglock);
+ percpu_down_write(&file_rwsem);
spin_lock(&blocked_lock_lock);
- return seq_hlist_start_percpu(&file_lock_list, &iter->li_cpu, *pos);
+ return seq_hlist_start_percpu(&file_lock_list.hlist, &iter->li_cpu, *pos);
}
static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
@@ -2713,14 +2764,14 @@ static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
struct locks_iterator *iter = f->private;
++iter->li_pos;
- return seq_hlist_next_percpu(v, &file_lock_list, &iter->li_cpu, pos);
+ return seq_hlist_next_percpu(v, &file_lock_list.hlist, &iter->li_cpu, pos);
}
static void locks_stop(struct seq_file *f, void *v)
__releases(&blocked_lock_lock)
{
spin_unlock(&blocked_lock_lock);
- lg_global_unlock(&file_lock_lglock);
+ percpu_up_write(&file_rwsem);
}
static const struct seq_operations locks_seq_operations = {
@@ -2761,10 +2812,13 @@ static int __init filelock_init(void)
filelock_cache = kmem_cache_create("file_lock_cache",
sizeof(struct file_lock), 0, SLAB_PANIC, NULL);
- lg_lock_init(&file_lock_lglock, "file_lock_lglock");
- for_each_possible_cpu(i)
- INIT_HLIST_HEAD(per_cpu_ptr(&file_lock_list, i));
+ for_each_possible_cpu(i) {
+ struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i);
+
+ spin_lock_init(&fll->lock);
+ INIT_HLIST_HEAD(&fll->hlist);
+ }
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-13 06:05:51 +0100