From 606e423e43bac0c2f7b85b682eb1ddd2a634586e Mon Sep 17 00:00:00 2001 From: OGAWA Hirofumi Date: Mon, 28 Apr 2008 02:16:27 -0700 Subject: [PATCH] fat: Update free_clusters even if it is untrusted 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fat/fatent.c | 7 +++++-- fs/fat/inode.c | 7 ++++--- include/linux/msdos_fs.h | 1 + 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c index 5fb366992b73..c7c8ab2209e1 100644 --- a/fs/fat/fatent.c +++ b/fs/fat/fatent.c @@ -450,7 +450,8 @@ int fat_alloc_clusters(struct inode *inode, int *cluster, int nr_cluster) 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 *inode, int *cluster, int nr_cluster) /* 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_block *sb) 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_block *sb) } while (fat_ent_next(sbi, &fatent)); } sbi->free_clusters = free; + sbi->free_clus_valid = 1; sb->s_dirt = 1; fatent_brelse(&fatent); out: diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 886f6095a378..1604a8a5c01f 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -537,7 +537,7 @@ static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 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 *sb, void *data, int silent, 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 *sb, void *data, int silent, 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 --git a/include/linux/msdos_fs.h b/include/linux/msdos_fs.h index 81fb9bc53220..0bca157ddca5 100644 --- a/include/linux/msdos_fs.h +++ b/include/linux/msdos_fs.h @@ -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 */ -- 2.20.1