[PATCH] Remove unnecessary kmalloc/kfree calls in mtdchar

This patch removes repeated calls to kmalloc / kfree in mtd_write /
mtd_read functions, replacing them by a single kmalloc / kfree pair.

Signed-off-by: Thiago Galesi <thiagogalesi@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 21 insertions, 13 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 6f044584bdc6..6b83aee8abb8 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -170,16 +170,22 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
 
         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
            and pass them directly to the MTD functions */
+
+        if (count > MAX_KMALLOC_SIZE)
+                kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
+        else
+                kbuf=kmalloc(count, GFP_KERNEL);
+
+        if (!kbuf)
+                return -ENOMEM;
+
         while (count) {
+
                 if (count > MAX_KMALLOC_SIZE)
                         len = MAX_KMALLOC_SIZE;
                 else
                         len = count;
 
-                kbuf=kmalloc(len,GFP_KERNEL);
-                if (!kbuf)
-                        return -ENOMEM;
-
                 switch (MTD_MODE(file)) {
                 case MTD_MODE_OTP_FACT:
                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
@@ -215,9 +221,9 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
                         return ret;
                 }
 
-                kfree(kbuf);
         }
 
+        kfree(kbuf);
         return total_retlen;
 } /* mtd_read */
 
@@ -241,18 +247,21 @@ static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count
         if (!count)
                 return 0;
 
+        if (count > MAX_KMALLOC_SIZE)
+                kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
+        else
+                kbuf=kmalloc(count, GFP_KERNEL);
+
+        if (!kbuf)
+                return -ENOMEM;
+
         while (count) {
+
                 if (count > MAX_KMALLOC_SIZE)
                         len = MAX_KMALLOC_SIZE;
                 else
                         len = count;
 
-                kbuf=kmalloc(len,GFP_KERNEL);
-                if (!kbuf) {
-                        printk("kmalloc is null\n");
-                        return -ENOMEM;
-                }
-
                 if (copy_from_user(kbuf, buf, len)) {
                         kfree(kbuf);
                         return -EFAULT;
@@ -282,10 +291,9 @@ static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count
                         kfree(kbuf);
                         return ret;
                 }
-
-                kfree(kbuf);
         }
 
+        kfree(kbuf);
         return total_retlen;
 } /* mtd_write */