login
Header Space

 
 

[PATCH v2] mballoc: fix hot spins after err_freebuddy and err_freemeta

Score:
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Aneesh Kumar K.V <aneesh.kumar@...>
Cc: <alex@...>, <sct@...>, <akpm@...>, <adilger@...>, <linux-ext4@...>, lkml <linux-kernel@...>
Date: Thursday, April 17, 2008 - 2:29 pm

Aneesh Kumar K.V wrote:


Thanks Aneesh,
---
Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
ext4_mb_init_backend() has a variable i of type ext4_group_t. which is typedefined
in include/linux/ext4_fs_i.h:34 to unsigned long. Since unsigned, i >= 0 is always
true, so fix hot spins after err_freebuddy and err_freemeta.
Also when meta_group_info cannot be allocated prevent a decrement of i when zero.

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
---
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index ef97f19..2c13dca 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2572,8 +2572,13 @@ static int ext4_mb_init_backend(struct super_block *sb)
 		meta_group_info[j] = kzalloc(len, GFP_KERNEL);
 		if (meta_group_info[j] == NULL) {
 			printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
-			i--;
-			goto err_freebuddy;
+			if (i != 0) {
+				i--;
+				goto err_freebuddy;
+			} else {
+				i = num_meta_group_infos - 1;
+				goto err_freemeta;
+			}
 		}
 		desc = ext4_get_group_desc(sb, i, NULL);
 		if (desc == NULL) {
@@ -2618,14 +2623,14 @@ static int ext4_mb_init_backend(struct super_block *sb)
 	return 0;
 
 err_freebuddy:
-	while (i >= 0) {
+	do {
 		kfree(ext4_get_group_info(sb, i));
-		i--;
-	}
-	i = num_meta_group_infos;
+	} while (i-- != 0);
+	i = num_meta_group_infos - 1;
 err_freemeta:
-	while (--i >= 0)
+	do {
 		kfree(sbi->s_group_info[i]);
+	} while (i-- != 0);
 	iput(sbi->s_buddy_cache);
 err_freesgi:
 	kfree(sbi->s_group_info);

--
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
[PATCH v2] mballoc: fix hot spins after err_freebuddy and er..., Roel Kluin, (Thu Apr 17, 2:29 pm)
speck-geostationary