fat: mmu_private race fix
mmu_private is 64bits value, hence it's not atomic to update.
So, the access rule for mmu_private is we must hold ->i_mutex. But,
fat_get_block() path doesn't follow the rule on non-allocation path.
This fixes by using i_size instead if non-allocation path.
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/inode.c b/fs/fat/inode.c
index be88208..9e37ad9 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -64,7 +64,7 @@
sector_t phys;
int err, offset;
- err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
+ err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
if (err)
return err;
if (phys) {
@@ -94,7 +94,7 @@
*max_blocks = min(mapped_blocks, *max_blocks);
MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
- err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
+ err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
if (err)
return err;