ext4: fix memory leaks in error path handling of ext4_ext_zeroout()

When EIO occurs after bio is submitted, there is no memory free
operation for bio, which results in memory leakage. And there is also
no check against bio_alloc() for bio.

Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Jing Zhang <zj.barak@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 236b834..228eeaf 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2544,7 +2544,7 @@ static void bi_complete(struct bio *bio, int error)
 /* FIXME!! we need to try to merge to left or right after zero-out  */
 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
 {
-       int ret = -EIO;
+       int ret;
        struct bio *bio;
        int blkbits, blocksize;
        sector_t ee_pblock;
@@ -2568,6 +2568,9 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
                        len = ee_len;
 
                bio = bio_alloc(GFP_NOIO, len);
+               if (!bio)
+                       return -ENOMEM;
+
                bio->bi_sector = ee_pblock;
                bio->bi_bdev   = inode->i_sb->s_bdev;
 
@@ -2595,17 +2598,15 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
                submit_bio(WRITE, bio);
                wait_for_completion(&event);
 
-               if (test_bit(BIO_UPTODATE, &bio->bi_flags))
-                       ret = 0;
-               else {
-                       ret = -EIO;
-                       break;
+               if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
+                       bio_put(bio);
+                       return -EIO;
                }
                bio_put(bio);
                ee_len    -= done;
                ee_pblock += done  << (blkbits - 9);
        }
-       return ret;
+       return 0;
 }
 
 #define EXT4_EXT_ZERO_LEN 7