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-rw-r--r--drivers/base/memory.c2
-rw-r--r--fs/dcache.c57
-rw-r--r--fs/namei.c16
-rw-r--r--fs/ocfs2/super.c2
-rw-r--r--include/linux/dcache.h19
-rw-r--r--include/linux/lockref.h71
-rw-r--r--include/uapi/linux/cm4000_cs.h1
-rw-r--r--ipc/msg.c5
-rw-r--r--kernel/time/timer_list.c41
-rw-r--r--mm/slab.h2
10 files changed, 146 insertions, 70 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 2b7813ec6d02..ec386ee9cb22 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -141,6 +141,8 @@ static ssize_t show_mem_removable(struct device *dev,
container_of(dev, struct memory_block, dev);
for (i = 0; i < sections_per_block; i++) {
+ if (!present_section_nr(mem->start_section_nr + i))
+ continue;
pfn = section_nr_to_pfn(mem->start_section_nr + i);
ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
}
diff --git a/fs/dcache.c b/fs/dcache.c
index 83cfb834db03..b949af850cd6 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -229,7 +229,7 @@ static void __d_free(struct rcu_head *head)
*/
static void d_free(struct dentry *dentry)
{
- BUG_ON(dentry->d_count);
+ BUG_ON(dentry->d_lockref.count);
this_cpu_dec(nr_dentry);
if (dentry->d_op && dentry->d_op->d_release)
dentry->d_op->d_release(dentry);
@@ -467,7 +467,7 @@ relock:
}
if (ref)
- dentry->d_count--;
+ dentry->d_lockref.count--;
/*
* inform the fs via d_prune that this dentry is about to be
* unhashed and destroyed.
@@ -513,15 +513,10 @@ void dput(struct dentry *dentry)
return;
repeat:
- if (dentry->d_count == 1)
+ if (dentry->d_lockref.count == 1)
might_sleep();
- spin_lock(&dentry->d_lock);
- BUG_ON(!dentry->d_count);
- if (dentry->d_count > 1) {
- dentry->d_count--;
- spin_unlock(&dentry->d_lock);
+ if (lockref_put_or_lock(&dentry->d_lockref))
return;
- }
if (dentry->d_flags & DCACHE_OP_DELETE) {
if (dentry->d_op->d_delete(dentry))
@@ -535,7 +530,7 @@ repeat:
dentry->d_flags |= DCACHE_REFERENCED;
dentry_lru_add(dentry);
- dentry->d_count--;
+ dentry->d_lockref.count--;
spin_unlock(&dentry->d_lock);
return;
@@ -590,7 +585,7 @@ int d_invalidate(struct dentry * dentry)
* We also need to leave mountpoints alone,
* directory or not.
*/
- if (dentry->d_count > 1 && dentry->d_inode) {
+ if (dentry->d_lockref.count > 1 && dentry->d_inode) {
if (S_ISDIR(dentry->d_inode->i_mode) || d_mountpoint(dentry)) {
spin_unlock(&dentry->d_lock);
return -EBUSY;
@@ -606,14 +601,12 @@ EXPORT_SYMBOL(d_invalidate);
/* This must be called with d_lock held */
static inline void __dget_dlock(struct dentry *dentry)
{
- dentry->d_count++;
+ dentry->d_lockref.count++;
}
static inline void __dget(struct dentry *dentry)
{
- spin_lock(&dentry->d_lock);
- __dget_dlock(dentry);
- spin_unlock(&dentry->d_lock);
+ lockref_get(&dentry->d_lockref);
}
struct dentry *dget_parent(struct dentry *dentry)
@@ -634,8 +627,8 @@ repeat:
goto repeat;
}
rcu_read_unlock();
- BUG_ON(!ret->d_count);
- ret->d_count++;
+ BUG_ON(!ret->d_lockref.count);
+ ret->d_lockref.count++;
spin_unlock(&ret->d_lock);
return ret;
}
@@ -718,7 +711,7 @@ restart:
spin_lock(&inode->i_lock);
hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
- if (!dentry->d_count) {
+ if (!dentry->d_lockref.count) {
__dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
@@ -763,12 +756,8 @@ static void try_prune_one_dentry(struct dentry *dentry)
/* Prune ancestors. */
dentry = parent;
while (dentry) {
- spin_lock(&dentry->d_lock);
- if (dentry->d_count > 1) {
- dentry->d_count--;
- spin_unlock(&dentry->d_lock);
+ if (lockref_put_or_lock(&dentry->d_lockref))
return;
- }
dentry = dentry_kill(dentry, 1);
}
}
@@ -793,7 +782,7 @@ static void shrink_dentry_list(struct list_head *list)
* the LRU because of laziness during lookup. Do not free
* it - just keep it off the LRU list.
*/
- if (dentry->d_count) {
+ if (dentry->d_lockref.count) {
dentry_lru_del(dentry);
spin_unlock(&dentry->d_lock);
continue;
@@ -913,7 +902,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
dentry_lru_del(dentry);
__d_shrink(dentry);
- if (dentry->d_count != 0) {
+ if (dentry->d_lockref.count != 0) {
printk(KERN_ERR
"BUG: Dentry %p{i=%lx,n=%s}"
" still in use (%d)"
@@ -922,7 +911,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
dentry->d_inode ?
dentry->d_inode->i_ino : 0UL,
dentry->d_name.name,
- dentry->d_count,
+ dentry->d_lockref.count,
dentry->d_sb->s_type->name,
dentry->d_sb->s_id);
BUG();
@@ -933,7 +922,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
list_del(&dentry->d_u.d_child);
} else {
parent = dentry->d_parent;
- parent->d_count--;
+ parent->d_lockref.count--;
list_del(&dentry->d_u.d_child);
}
@@ -981,7 +970,7 @@ void shrink_dcache_for_umount(struct super_block *sb)
dentry = sb->s_root;
sb->s_root = NULL;
- dentry->d_count--;
+ dentry->d_lockref.count--;
shrink_dcache_for_umount_subtree(dentry);
while (!hlist_bl_empty(&sb->s_anon)) {
@@ -1147,7 +1136,7 @@ resume:
* loop in shrink_dcache_parent() might not make any progress
* and loop forever.
*/
- if (dentry->d_count) {
+ if (dentry->d_lockref.count) {
dentry_lru_del(dentry);
} else if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
dentry_lru_move_list(dentry, dispose);
@@ -1269,7 +1258,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
smp_wmb();
dentry->d_name.name = dname;
- dentry->d_count = 1;
+ dentry->d_lockref.count = 1;
dentry->d_flags = 0;
spin_lock_init(&dentry->d_lock);
seqcount_init(&dentry->d_seq);
@@ -1970,7 +1959,7 @@ struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name)
goto next;
}
- dentry->d_count++;
+ dentry->d_lockref.count++;
found = dentry;
spin_unlock(&dentry->d_lock);
break;
@@ -2069,7 +2058,7 @@ again:
spin_lock(&dentry->d_lock);
inode = dentry->d_inode;
isdir = S_ISDIR(inode->i_mode);
- if (dentry->d_count == 1) {
+ if (dentry->d_lockref.count == 1) {
if (!spin_trylock(&inode->i_lock)) {
spin_unlock(&dentry->d_lock);
cpu_relax();
@@ -2948,7 +2937,7 @@ resume:
}
if (!(dentry->d_flags & DCACHE_GENOCIDE)) {
dentry->d_flags |= DCACHE_GENOCIDE;
- dentry->d_count--;
+ dentry->d_lockref.count--;
}
spin_unlock(&dentry->d_lock);
}
@@ -2956,7 +2945,7 @@ resume:
struct dentry *child = this_parent;
if (!(this_parent->d_flags & DCACHE_GENOCIDE)) {
this_parent->d_flags |= DCACHE_GENOCIDE;
- this_parent->d_count--;
+ this_parent->d_lockref.count--;
}
this_parent = try_to_ascend(this_parent, locked, seq);
if (!this_parent)
diff --git a/fs/namei.c b/fs/namei.c
index 89a612e392eb..7720fbd5277b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -536,8 +536,8 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry)
* a reference at this point.
*/
BUG_ON(!IS_ROOT(dentry) && dentry->d_parent != parent);
- BUG_ON(!parent->d_count);
- parent->d_count++;
+ BUG_ON(!parent->d_lockref.count);
+ parent->d_lockref.count++;
spin_unlock(&dentry->d_lock);
}
spin_unlock(&parent->d_lock);
@@ -3327,7 +3327,7 @@ void dentry_unhash(struct dentry *dentry)
{
shrink_dcache_parent(dentry);
spin_lock(&dentry->d_lock);
- if (dentry->d_count == 1)
+ if (dentry->d_lockref.count == 1)
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
}
@@ -3671,11 +3671,15 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0)
return -EINVAL;
/*
- * Using empty names is equivalent to using AT_SYMLINK_FOLLOW
- * on /proc/self/fd/<fd>.
+ * To use null names we require CAP_DAC_READ_SEARCH
+ * This ensures that not everyone will be able to create
+ * handlink using the passed filedescriptor.
*/
- if (flags & AT_EMPTY_PATH)
+ if (flags & AT_EMPTY_PATH) {
+ if (!capable(CAP_DAC_READ_SEARCH))
+ return -ENOENT;
how = LOOKUP_EMPTY;
+ }
if (flags & AT_SYMLINK_FOLLOW)
how |= LOOKUP_FOLLOW;
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 854d80955bf8..121da2dc3be8 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1022,7 +1022,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
struct inode *inode = NULL;
struct ocfs2_super *osb = NULL;
struct buffer_head *bh = NULL;
- char nodestr[8];
+ char nodestr[12];
struct ocfs2_blockcheck_stats stats;
trace_ocfs2_fill_super(sb, data, silent);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 4a12532da8c4..efdc94434c30 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -9,6 +9,7 @@
#include <linux/seqlock.h>
#include <linux/cache.h>
#include <linux/rcupdate.h>
+#include <linux/lockref.h>
struct nameidata;
struct path;
@@ -100,6 +101,8 @@ extern unsigned int full_name_hash(const unsigned char *, unsigned int);
# endif
#endif
+#define d_lock d_lockref.lock
+
struct dentry {
/* RCU lookup touched fields */
unsigned int d_flags; /* protected by d_lock */
@@ -112,8 +115,7 @@ struct dentry {
unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
/* Ref lookup also touches following */
- unsigned int d_count; /* protected by d_lock */
- spinlock_t d_lock; /* per dentry lock */
+ struct lockref d_lockref; /* per-dentry lock and refcount */
const struct dentry_operations *d_op;
struct super_block *d_sb; /* The root of the dentry tree */
unsigned long d_time; /* used by d_revalidate */
@@ -318,7 +320,7 @@ static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
assert_spin_locked(&dentry->d_lock);
if (!read_seqcount_retry(&dentry->d_seq, seq)) {
ret = 1;
- dentry->d_count++;
+ dentry->d_lockref.count++;
}
return ret;
@@ -326,7 +328,7 @@ static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
static inline unsigned d_count(const struct dentry *dentry)
{
- return dentry->d_count;
+ return dentry->d_lockref.count;
}
/* validate "insecure" dentry pointer */
@@ -357,17 +359,14 @@ extern char *dentry_path(struct dentry *, char *, int);
static inline struct dentry *dget_dlock(struct dentry *dentry)
{
if (dentry)
- dentry->d_count++;
+ dentry->d_lockref.count++;
return dentry;
}
static inline struct dentry *dget(struct dentry *dentry)
{
- if (dentry) {
- spin_lock(&dentry->d_lock);
- dget_dlock(dentry);
- spin_unlock(&dentry->d_lock);
- }
+ if (dentry)
+ lockref_get(&dentry->d_lockref);
return dentry;
}
diff --git a/include/linux/lockref.h b/include/linux/lockref.h
new file mode 100644
index 000000000000..01233e01627a
--- /dev/null
+++ b/include/linux/lockref.h
@@ -0,0 +1,71 @@
+#ifndef __LINUX_LOCKREF_H
+#define __LINUX_LOCKREF_H
+
+/*
+ * Locked reference counts.
+ *
+ * These are different from just plain atomic refcounts in that they
+ * are atomic with respect to the spinlock that goes with them. In
+ * particular, there can be implementations that don't actually get
+ * the spinlock for the common decrement/increment operations, but they
+ * still have to check that the operation is done semantically as if
+ * the spinlock had been taken (using a cmpxchg operation that covers
+ * both the lock and the count word, or using memory transactions, for
+ * example).
+ */
+
+#include <linux/spinlock.h>
+
+struct lockref {
+ spinlock_t lock;
+ unsigned int count;
+};
+
+/**
+ * lockref_get - Increments reference count unconditionally
+ * @lockcnt: pointer to lockref structure
+ *
+ * This operation is only valid if you already hold a reference
+ * to the object, so you know the count cannot be zero.
+ */
+static inline void lockref_get(struct lockref *lockref)
+{
+ spin_lock(&lockref->lock);
+ lockref->count++;
+ spin_unlock(&lockref->lock);
+}
+
+/**
+ * lockref_get_not_zero - Increments count unless the count is 0
+ * @lockcnt: pointer to lockref structure
+ * Return: 1 if count updated successfully or 0 if count is 0
+ */
+static inline int lockref_get_not_zero(struct lockref *lockref)
+{
+ int retval = 0;
+
+ spin_lock(&lockref->lock);
+ if (lockref->count) {
+ lockref->count++;
+ retval = 1;
+ }
+ spin_unlock(&lockref->lock);
+ return retval;
+}
+
+/**
+ * lockref_put_or_lock - decrements count unless count <= 1 before decrement
+ * @lockcnt: pointer to lockref structure
+ * Return: 1 if count updated successfully or 0 if count <= 1 and lock taken
+ */
+static inline int lockref_put_or_lock(struct lockref *lockref)
+{
+ spin_lock(&lockref->lock);
+ if (lockref->count <= 1)
+ return 0;
+ lockref->count--;
+ spin_unlock(&lockref->lock);
+ return 1;
+}
+
+#endif /* __LINUX_LOCKREF_H */
diff --git a/include/uapi/linux/cm4000_cs.h b/include/uapi/linux/cm4000_cs.h
index bc51f77db918..1217f751a1bc 100644
--- a/include/uapi/linux/cm4000_cs.h
+++ b/include/uapi/linux/cm4000_cs.h
@@ -2,6 +2,7 @@
#define _UAPI_CM4000_H_
#include <linux/types.h>
+#include <linux/ioctl.h>
#define MAX_ATR 33
diff --git a/ipc/msg.c b/ipc/msg.c
index bd60d7e159e8..9f29d9e89bac 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -839,7 +839,7 @@ static inline void free_copy(struct msg_msg *copy)
static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
{
- struct msg_msg *msg;
+ struct msg_msg *msg, *found = NULL;
long count = 0;
list_for_each_entry(msg, &msq->q_messages, m_list) {
@@ -848,6 +848,7 @@ static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
*msgtyp, mode)) {
if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
*msgtyp = msg->m_type - 1;
+ found = msg;
} else if (mode == SEARCH_NUMBER) {
if (*msgtyp == count)
return msg;
@@ -857,7 +858,7 @@ static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
}
}
- return ERR_PTR(-EAGAIN);
+ return found ?: ERR_PTR(-EAGAIN);
}
long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 3bdf28323012..61ed862cdd37 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -265,10 +265,9 @@ static inline void timer_list_header(struct seq_file *m, u64 now)
static int timer_list_show(struct seq_file *m, void *v)
{
struct timer_list_iter *iter = v;
- u64 now = ktime_to_ns(ktime_get());
if (iter->cpu == -1 && !iter->second_pass)
- timer_list_header(m, now);
+ timer_list_header(m, iter->now);
else if (!iter->second_pass)
print_cpu(m, iter->cpu, iter->now);
#ifdef CONFIG_GENERIC_CLOCKEVENTS
@@ -298,33 +297,41 @@ void sysrq_timer_list_show(void)
return;
}
-static void *timer_list_start(struct seq_file *file, loff_t *offset)
+static void *move_iter(struct timer_list_iter *iter, loff_t offset)
{
- struct timer_list_iter *iter = file->private;
-
- if (!*offset) {
- iter->cpu = -1;
- iter->now = ktime_to_ns(ktime_get());
- } else if (iter->cpu >= nr_cpu_ids) {
+ for (; offset; offset--) {
+ iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
+ if (iter->cpu >= nr_cpu_ids) {
#ifdef CONFIG_GENERIC_CLOCKEVENTS
- if (!iter->second_pass) {
- iter->cpu = -1;
- iter->second_pass = true;
- } else
- return NULL;
+ if (!iter->second_pass) {
+ iter->cpu = -1;
+ iter->second_pass = true;
+ } else
+ return NULL;
#else
- return NULL;
+ return NULL;
#endif
+ }
}
return iter;
}
+static void *timer_list_start(struct seq_file *file, loff_t *offset)
+{
+ struct timer_list_iter *iter = file->private;
+
+ if (!*offset)
+ iter->now = ktime_to_ns(ktime_get());
+ iter->cpu = -1;
+ iter->second_pass = false;
+ return move_iter(iter, *offset);
+}
+
static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
{
struct timer_list_iter *iter = file->private;
- iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
++*offset;
- return timer_list_start(file, offset);
+ return move_iter(iter, 1);
}
static void timer_list_stop(struct seq_file *seq, void *v)
diff --git a/mm/slab.h b/mm/slab.h
index 620ceeddbe1a..a535033f7e9a 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -162,6 +162,8 @@ static inline const char *cache_name(struct kmem_cache *s)
static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
{
+ if (!s->memcg_params)
+ return NULL;
return s->memcg_params->memcg_caches[idx];
}