ext4: recover from filesystem corruption when reading

[u-boot] / fs / ext4 / ext4fs.c

diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index b0c7303aa410034fc6091a2a56d02f75def6936a..9ee2caf2fa1a7d6db2395e0e98d0f03be2e2091d 100644 (file)
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -64,6 +64,9 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
        char *delayed_buf = NULL;
        short status;
 
+       if (blocksize <= 0)
+               return -1;
+
        /* Adjust len so it we can't read past the end of the file. */
        if (len + pos > filesize)
                len = (filesize - pos);
@@ -127,6 +130,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
                                        (blockend >> log2blksz);
                        }
                } else {
+                       int n;
                        if (previous_block_number != -1) {
                                /* spill */
                                status = ext4fs_devread(delayed_start,
@@ -137,7 +141,11 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
                                        return -1;
                                previous_block_number = -1;
                        }
-                       memset(buf, 0, blocksize - skipfirst);
+                       /* Zero no more than `len' bytes. */
+                       n = blocksize - skipfirst;
+                       if (n > len)
+                               n = len;
+                       memset(buf, 0, n);
                }
                buf += blocksize - skipfirst;
        }