Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 606e423e authored by OGAWA Hirofumi's avatar OGAWA Hirofumi Committed by Linus Torvalds
Browse files

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: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1ae43f82

fs/fat/fatent.c

+5 −2
Original line number Diff line number Diff line
@@ -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:

fs/fat/inode.c

+4 −3
Original line number Diff line number Diff line
@@ -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);

		}

include/linux/msdos_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */