4 files changed, 60 insertions, 9 deletions

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 08c3d76b24ca..71bf5f4ae84c 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -178,6 +178,8 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 	if (p->psi->erase)
 		p->psi->erase(p->type, p->id, p->count,
 			      dentry->d_inode->i_ctime, p->psi);
+	else
+		return -EPERM;
 
 	return simple_unlink(dir, dentry);
 }
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 4637ec4169cd..422962ae9fc2 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -241,17 +241,15 @@ int pstore_register(struct pstore_info *psi)
 {
 	struct module *owner = psi->owner;
 
+	if (backend && strcmp(backend, psi->name))
+		return -EPERM;
+
 	spin_lock(&pstore_lock);
 	if (psinfo) {
 		spin_unlock(&pstore_lock);
 		return -EBUSY;
 	}
 
-	if (backend && strcmp(backend, psi->name)) {
-		spin_unlock(&pstore_lock);
-		return -EINVAL;
-	}
-
 	if (!psi->write)
 		psi->write = pstore_write_compat;
 	psinfo = psi;
@@ -276,6 +274,9 @@ int pstore_register(struct pstore_info *psi)
 		add_timer(&pstore_timer);
 	}
 
+	pr_info("pstore: Registered %s as persistent store backend\n",
+		psi->name);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pstore_register);
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index c6bb77ca35b5..a6119f9469e2 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -400,8 +400,6 @@ static int ramoops_probe(struct platform_device *pdev)
 		goto fail_out;
 	}
 
-	if (!is_power_of_2(pdata->mem_size))
-		pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
 	if (!is_power_of_2(pdata->record_size))
 		pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 	if (!is_power_of_2(pdata->console_size))
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 59337326e288..de272d426763 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -46,7 +46,7 @@ static inline size_t buffer_start(struct persistent_ram_zone *prz)
 }
 
 /* increase and wrap the start pointer, returning the old value */
-static inline size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
+static size_t buffer_start_add_atomic(struct persistent_ram_zone *prz, size_t a)
 {
 	int old;
 	int new;
@@ -62,7 +62,7 @@ static inline size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
 }
 
 /* increase the size counter until it hits the max size */
-static inline void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
+static void buffer_size_add_atomic(struct persistent_ram_zone *prz, size_t a)
 {
 	size_t old;
 	size_t new;
@@ -78,6 +78,53 @@ static inline void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
 	} while (atomic_cmpxchg(&prz->buffer->size, old, new) != old);
 }
 
+static DEFINE_RAW_SPINLOCK(buffer_lock);
+
+/* increase and wrap the start pointer, returning the old value */
+static size_t buffer_start_add_locked(struct persistent_ram_zone *prz, size_t a)
+{
+	int old;
+	int new;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&buffer_lock, flags);
+
+	old = atomic_read(&prz->buffer->start);
+	new = old + a;
+	while (unlikely(new > prz->buffer_size))
+		new -= prz->buffer_size;
+	atomic_set(&prz->buffer->start, new);
+
+	raw_spin_unlock_irqrestore(&buffer_lock, flags);
+
+	return old;
+}
+
+/* increase the size counter until it hits the max size */
+static void buffer_size_add_locked(struct persistent_ram_zone *prz, size_t a)
+{
+	size_t old;
+	size_t new;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&buffer_lock, flags);
+
+	old = atomic_read(&prz->buffer->size);
+	if (old == prz->buffer_size)
+		goto exit;
+
+	new = old + a;
+	if (new > prz->buffer_size)
+		new = prz->buffer_size;
+	atomic_set(&prz->buffer->size, new);
+
+exit:
+	raw_spin_unlock_irqrestore(&buffer_lock, flags);
+}
+
+static size_t (*buffer_start_add)(struct persistent_ram_zone *, size_t) = buffer_start_add_atomic;
+static void (*buffer_size_add)(struct persistent_ram_zone *, size_t) = buffer_size_add_atomic;
+
 static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
 	uint8_t *data, size_t len, uint8_t *ecc)
 {
@@ -372,6 +419,9 @@ static void *persistent_ram_iomap(phys_addr_t start, size_t size)
 		return NULL;
 	}
 
+	buffer_start_add = buffer_start_add_locked;
+	buffer_size_add = buffer_size_add_locked;
+
 	return ioremap(start, size);
 }