From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
This changes ->free_clusters and ->prev_free from "int" to "unsigned int".
These value should be never negative value (but it's using 0xffffffff(-1) as
undefined state).
With this changes, fatfs would handle the corruption of free_clusters
more proper.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/fat/fatent.c | 3 +--
25-akpm/fs/fat/inode.c | 6 +++++-
25-akpm/include/linux/msdos_fs.h | 4 ++--
3 files changed, 8 insertions(+), 5 deletions(-)
diff -puN fs/fat/fatent.c~fat-use-unsigned-int-for-free_clusters-and fs/fat/fatent.c
--- 25/fs/fat/fatent.c~fat-use-unsigned-int-for-free_clusters-and Sun Mar 6 17:13:10 2005
+++ 25-akpm/fs/fat/fatent.c Sun Mar 6 17:13:10 2005
@@ -453,8 +453,7 @@ int fat_alloc_clusters(struct inode *ino
fatent_init(&fatent);
fatent_set_entry(&fatent, sbi->prev_free + 1);
while (count < sbi->max_cluster) {
- fatent.entry %= sbi->max_cluster;
- if (fatent.entry < FAT_START_ENT)
+ if (fatent.entry >= sbi->max_cluster)
fatent.entry = FAT_START_ENT;
fatent_set_entry(&fatent, fatent.entry);
err = fat_ent_read_block(sb, &fatent);
diff -puN fs/fat/inode.c~fat-use-unsigned-int-for-free_clusters-and fs/fat/inode.c
--- 25/fs/fat/inode.c~fat-use-unsigned-int-for-free_clusters-and Sun Mar 6 17:13:10 2005
+++ 25-akpm/fs/fat/inode.c Sun Mar 6 17:13:10 2005
@@ -1163,7 +1163,7 @@ int fat_fill_super(struct super_block *s
sbi->fat_length = le16_to_cpu(b->fat_length);
sbi->root_cluster = 0;
sbi->free_clusters = -1; /* Don't know yet */
- sbi->prev_free = -1;
+ sbi->prev_free = FAT_START_ENT;
if (!sbi->fat_length && b->fat32_length) {
struct fat_boot_fsinfo *fsinfo;
@@ -1247,6 +1247,10 @@ int fat_fill_super(struct super_block *s
/* check the free_clusters, it's not necessarily correct */
if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
sbi->free_clusters = -1;
+ /* check the prev_free, it's not necessarily correct */
+ sbi->prev_free %= sbi->max_cluster;
+ if (sbi->prev_free < FAT_START_ENT)
+ sbi->prev_free = FAT_START_ENT;
brelse(bh);
diff -puN include/linux/msdos_fs.h~fat-use-unsigned-int-for-free_clusters-and include/linux/msdos_fs.h
--- 25/include/linux/msdos_fs.h~fat-use-unsigned-int-for-free_clusters-and Sun Mar 6 17:13:10 2005
+++ 25-akpm/include/linux/msdos_fs.h Sun Mar 6 17:13:10 2005
@@ -225,8 +225,8 @@ struct msdos_sb_info {
unsigned long root_cluster; /* first cluster of the root directory */
unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
struct semaphore fat_lock;
- int prev_free; /* previously allocated cluster number */
- int free_clusters; /* -1 if undefined */
+ unsigned int prev_free; /* previously allocated cluster number */
+ unsigned int free_clusters; /* -1 if undefined */
struct fat_mount_options options;
struct nls_table *nls_disk; /* Codepage used on disk */
struct nls_table *nls_io; /* Charset used for input and display */
_