lib: percpu_counter_init error handling

alloc_percpu can fail, propagate that error.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ext2/super.c

@@ -653,6 +653,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	int db_count;
 	int i, j;
 	__le32 features;
+	int err;
 
 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
@@ -906,12 +907,20 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 	spin_lock_init(&sbi->s_next_gen_lock);
 
-	percpu_counter_init(&sbi->s_freeblocks_counter,
+	err = percpu_counter_init(&sbi->s_freeblocks_counter,
 				ext2_count_free_blocks(sb));
-	percpu_counter_init(&sbi->s_freeinodes_counter,
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_freeinodes_counter,
 				ext2_count_free_inodes(sb));
-	percpu_counter_init(&sbi->s_dirs_counter,
+	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_dirs_counter,
 				ext2_count_dirs(sb));
+	}
+	if (err) {
+		printk(KERN_ERR "EXT2-fs: insufficient memory\n");
+		goto failed_mount3;
+	}
 	/*
 	 * set up enough so that it can read an inode
 	 */

fs/ext3/super.c

@@ -1416,6 +1416,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
 	int i;
 	int needs_recovery;
 	__le32 features;
+	int err;
 
 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
@@ -1675,12 +1676,20 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 	spin_lock_init(&sbi->s_next_gen_lock);
 
-	percpu_counter_init(&sbi->s_freeblocks_counter,
-		ext3_count_free_blocks(sb));
-	percpu_counter_init(&sbi->s_freeinodes_counter,
-		ext3_count_free_inodes(sb));
-	percpu_counter_init(&sbi->s_dirs_counter,
-		ext3_count_dirs(sb));
+	err = percpu_counter_init(&sbi->s_freeblocks_counter,
+			ext3_count_free_blocks(sb));
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_freeinodes_counter,
+				ext3_count_free_inodes(sb));
+	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_dirs_counter,
+				ext3_count_dirs(sb));
+	}
+	if (err) {
+		printk(KERN_ERR "EXT3-fs: insufficient memory\n");
+		goto failed_mount3;
+	}
 
 	/* per fileystem reservation list head & lock */
 	spin_lock_init(&sbi->s_rsv_window_lock);

fs/ext4/super.c

@@ -1479,6 +1479,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	int needs_recovery;
 	__le32 features;
 	__u64 blocks_count;
+	int err;
 
 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
@@ -1759,12 +1760,20 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 	spin_lock_init(&sbi->s_next_gen_lock);
 
-	percpu_counter_init(&sbi->s_freeblocks_counter,
-		ext4_count_free_blocks(sb));
-	percpu_counter_init(&sbi->s_freeinodes_counter,
-		ext4_count_free_inodes(sb));
-	percpu_counter_init(&sbi->s_dirs_counter,
-		ext4_count_dirs(sb));
+	err = percpu_counter_init(&sbi->s_freeblocks_counter,
+			ext4_count_free_blocks(sb));
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_freeinodes_counter,
+				ext4_count_free_inodes(sb));
+	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_dirs_counter,
+				ext4_count_dirs(sb));
+	}
+	if (err) {
+		printk(KERN_ERR "EXT4-fs: insufficient memory\n");
+		goto failed_mount3;
+	}
 
 	/* per fileystem reservation list head & lock */
 	spin_lock_init(&sbi->s_rsv_window_lock);

include/linux/percpu_counter.h

@@ -30,7 +30,7 @@ struct percpu_counter {
 #define FBC_BATCH	(NR_CPUS*4)
 #endif
 
-void percpu_counter_init(struct percpu_counter *fbc, s64 amount);
+int percpu_counter_init(struct percpu_counter *fbc, s64 amount);
 void percpu_counter_destroy(struct percpu_counter *fbc);
 void percpu_counter_set(struct percpu_counter *fbc, s64 amount);
 void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch);
@@ -78,9 +78,10 @@ struct percpu_counter {
 	s64 count;
 };
 
-static inline void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
+static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 {
 	fbc->count = amount;
+	return 0;
 }
 
 static inline void percpu_counter_destroy(struct percpu_counter *fbc)

lib/percpu_counter.c

@@ -68,21 +68,27 @@ s64 __percpu_counter_sum(struct percpu_counter *fbc)
 }
 EXPORT_SYMBOL(__percpu_counter_sum);
 
-void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
+int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 {
 	spin_lock_init(&fbc->lock);
 	fbc->count = amount;
 	fbc->counters = alloc_percpu(s32);
+	if (!fbc->counters)
+		return -ENOMEM;
 #ifdef CONFIG_HOTPLUG_CPU
 	mutex_lock(&percpu_counters_lock);
 	list_add(&fbc->list, &percpu_counters);
 	mutex_unlock(&percpu_counters_lock);
 #endif
+	return 0;
 }
 EXPORT_SYMBOL(percpu_counter_init);
 
 void percpu_counter_destroy(struct percpu_counter *fbc)
 {
+	if (!fbc->counters)
+		return;
+
 	free_percpu(fbc->counters);
 #ifdef CONFIG_HOTPLUG_CPU
 	mutex_lock(&percpu_counters_lock);