lkml.org 
[lkml]   [2008]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH 5/9] fat: Update free_clusters even if it is untrusted
From
Date

Currently, free_clusters is not updated until it is trusted, because
Windows doesn't update it correctly.

But if user is using FAT driver of Linux, it updates free_clusters
correctly. Instead, this updates it even if it's untrusted, so if
free_clustes is correct, now keep correct value.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---
fs/fat/fatent.c | 7 +++++--
fs/fat/inode.c | 7 ++++---
include/linux/msdos_fs.h | 1 +
3 files changed, 10 insertions(+), 5 deletions(-)
diff -puN include/linux/msdos_fs.h~fat_fix-free_clusters-check include/linux/msdos_fs.h
--- linux-2.6/include/linux/msdos_fs.h~fat_fix-free_clusters-check 2008-03-14 05:38:40.000000000 +0900
+++ linux-2.6-hirofumi/include/linux/msdos_fs.h 2008-03-14 05:38:40.000000000 +0900
@@ -233,6 +233,7 @@ struct msdos_sb_info {
struct mutex fat_lock;
unsigned int prev_free; /* previously allocated cluster number */
unsigned int free_clusters; /* -1 if undefined */
+ unsigned int free_clus_valid; /* is free_clusters valid? */
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 */
diff -puN fs/fat/inode.c~fat_fix-free_clusters-check fs/fat/inode.c
--- linux-2.6/fs/fat/inode.c~fat_fix-free_clusters-check 2008-03-14 05:38:40.000000000 +0900
+++ linux-2.6-hirofumi/fs/fat/inode.c 2008-03-14 05:38:40.000000000 +0900
@@ -537,7 +537,7 @@ static int fat_statfs(struct dentry *den
struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);

/* If the count of free cluster is still unknown, counts it here. */
- if (sbi->free_clusters == -1) {
+ if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
int err = fat_count_free_clusters(dentry->d_sb);
if (err)
return err;
@@ -1274,6 +1274,7 @@ 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->free_clus_valid = 0;
sbi->prev_free = FAT_START_ENT;

if (!sbi->fat_length && b->fat32_length) {
@@ -1309,8 +1310,8 @@ int fat_fill_super(struct super_block *s
sbi->fsinfo_sector);
} else {
if (sbi->options.usefree)
- sbi->free_clusters =
- le32_to_cpu(fsinfo->free_clusters);
+ sbi->free_clus_valid = 1;
+ sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
}

diff -puN fs/fat/fatent.c~fat_fix-free_clusters-check fs/fat/fatent.c
--- linux-2.6/fs/fat/fatent.c~fat_fix-free_clusters-check 2008-03-14 05:38:40.000000000 +0900
+++ linux-2.6-hirofumi/fs/fat/fatent.c 2008-03-14 05:38:40.000000000 +0900
@@ -450,7 +450,8 @@ int fat_alloc_clusters(struct inode *ino
BUG_ON(nr_cluster > (MAX_BUF_PER_PAGE / 2)); /* fixed limit */

lock_fat(sbi);
- if (sbi->free_clusters != -1 && sbi->free_clusters < nr_cluster) {
+ if (sbi->free_clusters != -1 && sbi->free_clus_valid &&
+ sbi->free_clusters < nr_cluster) {
unlock_fat(sbi);
return -ENOSPC;
}
@@ -504,6 +505,7 @@ int fat_alloc_clusters(struct inode *ino

/* Couldn't allocate the free entries */
sbi->free_clusters = 0;
+ sbi->free_clus_valid = 1;
sb->s_dirt = 1;
err = -ENOSPC;

@@ -615,7 +617,7 @@ int fat_count_free_clusters(struct super
int err = 0, free;

lock_fat(sbi);
- if (sbi->free_clusters != -1)
+ if (sbi->free_clusters != -1 && sbi->free_clus_valid)
goto out;

reada_blocks = FAT_READA_SIZE >> sb->s_blocksize_bits;
@@ -643,6 +645,7 @@ int fat_count_free_clusters(struct super
} while (fat_ent_next(sbi, &fatent));
}
sbi->free_clusters = free;
+ sbi->free_clus_valid = 1;
sb->s_dirt = 1;
fatent_brelse(&fatent);
out:
_

\
 
 \ /
  Last update: 2008-04-20 20:31    [from the cache]
©2003-2011 Jasper Spaans