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authorJan Kara <jack@suse.cz>2013-05-31 19:39:56 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-21 18:14:41 -0700
commit4b9cf8edf9d6203e0ed7a38844f8c3c35b101a61 (patch)
parentd19c4370e3e590ed083c77238866719025476108 (diff)
ext4: fix overflow when counting used blocks on 32-bit architectures
commit 8af8eecc1331dbf5e8c662022272cf667e213da5 upstream. The arithmetics adding delalloc blocks to the number of used blocks in ext4_getattr() can easily overflow on 32-bit archs as we first multiply number of blocks by blocksize and then divide back by 512. Make the arithmetics more clever and also use proper type (unsigned long long instead of unsigned long). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 7e56946a5199..5de8a2703994 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5481,7 +5481,7 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
struct inode *inode;
- unsigned long delalloc_blocks;
+ unsigned long long delalloc_blocks;
inode = dentry->d_inode;
generic_fillattr(inode, stat);
@@ -5498,7 +5498,7 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
- stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
+ stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits-9);
return 0;