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 <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 5fb3669..c7c8ab2 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -450,7 +450,8 @@
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 @@
/* 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 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 @@
} while (fat_ent_next(sbi, &fatent));
}
sbi->free_clusters = free;
+ sbi->free_clus_valid = 1;
sb->s_dirt = 1;
fatent_brelse(&fatent);
out: