udf: Use of s_alloc_mutex to serialize udf_relocate_blocks() execution

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/udf/partition.c b/fs/udf/partition.c
index 745eb209be0cf97998cd5ccb85be386557ba9075..a71090ea0e07034c5eb24cdcb8bbea0009ccb8a9 100644 (file)
--- a/fs/udf/partition.c
+++ b/fs/udf/partition.c
@@ -25,6 +25,7 @@
 #include <linux/fs.h>
 #include <linux/string.h>
 #include <linux/buffer_head.h>
+#include <linux/mutex.h>
 
 uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
                        uint16_t partition, uint32_t offset)
@@ -159,7 +160,9 @@ int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
        struct udf_sb_info *sbi = UDF_SB(sb);
        u16 reallocationTableLen;
        struct buffer_head *bh;
+       int ret = 0;
 
+       mutex_lock(&sbi->s_alloc_mutex);
        for (i = 0; i < sbi->s_partitions; i++) {
                struct udf_part_map *map = &sbi->s_partmaps[i];
                if (old_block > map->s_partition_root &&
@@ -175,8 +178,10 @@ int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
                                        break;
                                }
 
-                       if (!st)
-                               return 1;
+                       if (!st) {
+                               ret = 1;
+                               goto out;
+                       }
 
                        reallocationTableLen =
                                        le16_to_cpu(st->reallocationTableLen);
@@ -207,14 +212,16 @@ int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
                                                     ((old_block -
                                                        map->s_partition_root) &
                                                     (sdata->s_packet_len - 1));
-                                       return 0;
+                                       ret = 0;
+                                       goto out;
                                } else if (origLoc == packet) {
                                        *new_block = le32_to_cpu(
                                                        entry->mappedLocation) +
                                                     ((old_block -
                                                        map->s_partition_root) &
                                                     (sdata->s_packet_len - 1));
-                                       return 0;
+                                       ret = 0;
+                                       goto out;
                                } else if (origLoc > packet)
                                        break;
                        }
@@ -251,20 +258,24 @@ int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
                                              st->mapEntry[k].mappedLocation) +
                                        ((old_block - map->s_partition_root) &
                                         (sdata->s_packet_len - 1));
-                               return 0;
+                               ret = 0;
+                               goto out;
                        }
 
-                       return 1;
+                       ret = 1;
+                       goto out;
                } /* if old_block */
        }
 
        if (i == sbi->s_partitions) {
                /* outside of partitions */
                /* for now, fail =) */
-               return 1;
+               ret = 1;
        }
 
-       return 0;
+out:
+       mutex_unlock(&sbi->s_alloc_mutex);
+       return ret;
 }
 
 static uint32_t udf_try_read_meta(struct inode *inode, uint32_t block,