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ocfs2: fix shift left overflow

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When using a large volume, for example 9T volume with 2T already used,
frequent creation of small files with O_DIRECT when the IO is not
cluster aligned may clear sectors in the wrong place.  This will cause
filesystem corruption.

This is because p_cpos is a u32.  When calculating the corresponding
sector it should be converted to u64 first, otherwise it may overflow.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: <stable@vger.kernel.org>	[4.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joseph Qi 2015-08-06 15:46:48 -07:00 committed by Linus Torvalds
parent 18896451ea
commit 32e5a2a2be
1 changed files with 2 additions and 2 deletions
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4
fs/ocfs2/aops.c
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@ -685,7 +685,7 @@ static int ocfs2_direct_IO_zero_extend(struct ocfs2_super *osb,
if (p_cpos && !(ext_flags & OCFS2_EXT_UNWRITTEN)) {
u64 s = i_size_read(inode);
sector_t sector = (p_cpos << (osb->s_clustersize_bits - 9)) +
sector_t sector = ((u64)p_cpos << (osb->s_clustersize_bits - 9)) +
(do_div(s, osb->s_clustersize) >> 9);
ret = blkdev_issue_zeroout(osb->sb->s_bdev, sector,
@ -910,7 +910,7 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
BUG_ON(!p_cpos || (ext_flags & OCFS2_EXT_UNWRITTEN));
ret = blkdev_issue_zeroout(osb->sb->s_bdev,
p_cpos << (osb->s_clustersize_bits - 9),
(u64)p_cpos << (osb->s_clustersize_bits - 9),
zero_len_head >> 9, GFP_NOFS, false);
if (ret < 0)
mlog_errno(ret);