Commit 14a5275d authored by Joseph Qi's avatar Joseph Qi Committed by Linus Torvalds
Browse files

ocfs2: do not use ocfs2_zero_extend during direct IO



In ocfs2_direct_IO_write, we use ocfs2_zero_extend to zero allocated
clusters in case of cluster not aligned.  But ocfs2_zero_extend uses page
cache, this may happen that it clears the data which blockdev_direct_IO
has already written.

We should use blkdev_issue_zeroout instead of ocfs2_zero_extend during
direct IO.

So fix this issue by introducing ocfs2_direct_IO_zero_extend and
ocfs2_direct_IO_extend_no_holes.
Reported-by: default avatarYiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: default avatarJoseph Qi <joseph.qi@huawei.com>
Tested-by: default avatarYiwen Jiang <jiangyiwen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 37a8d89a
......@@ -663,6 +663,117 @@ static int ocfs2_is_overwrite(struct ocfs2_super *osb,
return 0;
}
static int ocfs2_direct_IO_zero_extend(struct ocfs2_super *osb,
struct inode *inode, loff_t offset,
u64 zero_len, int cluster_align)
{
u32 p_cpos = 0;
u32 v_cpos = ocfs2_bytes_to_clusters(osb->sb, i_size_read(inode));
unsigned int num_clusters = 0;
unsigned int ext_flags = 0;
int ret = 0;
if (offset <= i_size_read(inode) || cluster_align)
return 0;
ret = ocfs2_get_clusters(inode, v_cpos, &p_cpos, &num_clusters,
&ext_flags);
if (ret < 0) {
mlog_errno(ret);
return ret;
}
if (p_cpos && !(ext_flags & OCFS2_EXT_UNWRITTEN)) {
u64 s = i_size_read(inode);
sector_t sector = (p_cpos << (osb->s_clustersize_bits - 9)) +
(do_div(s, osb->s_clustersize) >> 9);
ret = blkdev_issue_zeroout(osb->sb->s_bdev, sector,
zero_len >> 9, GFP_NOFS, false);
if (ret < 0)
mlog_errno(ret);
}
return ret;
}
static int ocfs2_direct_IO_extend_no_holes(struct ocfs2_super *osb,
struct inode *inode, loff_t offset)
{
u64 zero_start, zero_len, total_zero_len;
u32 p_cpos = 0, clusters_to_add;
u32 v_cpos = ocfs2_bytes_to_clusters(osb->sb, i_size_read(inode));
unsigned int num_clusters = 0;
unsigned int ext_flags = 0;
u32 size_div, offset_div;
int ret = 0;
{
u64 o = offset;
u64 s = i_size_read(inode);
offset_div = do_div(o, osb->s_clustersize);
size_div = do_div(s, osb->s_clustersize);
}
if (offset <= i_size_read(inode))
return 0;
clusters_to_add = ocfs2_bytes_to_clusters(inode->i_sb, offset) -
ocfs2_bytes_to_clusters(inode->i_sb, i_size_read(inode));
total_zero_len = offset - i_size_read(inode);
if (clusters_to_add)
total_zero_len -= offset_div;
/* Allocate clusters to fill out holes, and this is only needed
* when we add more than one clusters. Otherwise the cluster will
* be allocated during direct IO */
if (clusters_to_add > 1) {
ret = ocfs2_extend_allocation(inode,
OCFS2_I(inode)->ip_clusters,
clusters_to_add - 1, 0);
if (ret) {
mlog_errno(ret);
goto out;
}
}
while (total_zero_len) {
ret = ocfs2_get_clusters(inode, v_cpos, &p_cpos, &num_clusters,
&ext_flags);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
zero_start = ocfs2_clusters_to_bytes(osb->sb, p_cpos) +
size_div;
zero_len = ocfs2_clusters_to_bytes(osb->sb, num_clusters) -
size_div;
zero_len = min(total_zero_len, zero_len);
if (p_cpos && !(ext_flags & OCFS2_EXT_UNWRITTEN)) {
ret = blkdev_issue_zeroout(osb->sb->s_bdev,
zero_start >> 9, zero_len >> 9,
GFP_NOFS, false);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
}
total_zero_len -= zero_len;
v_cpos += ocfs2_bytes_to_clusters(osb->sb, zero_len + size_div);
/* Only at first iteration can be cluster not aligned.
* So set size_div to 0 for the rest */
size_div = 0;
}
out:
return ret;
}
static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
struct iov_iter *iter,
loff_t offset)
......@@ -677,8 +788,8 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
struct buffer_head *di_bh = NULL;
size_t count = iter->count;
journal_t *journal = osb->journal->j_journal;
u32 zero_len;
int cluster_align;
u64 zero_len_head, zero_len_tail;
int cluster_align_head, cluster_align_tail;
loff_t final_size = offset + count;
int append_write = offset >= i_size_read(inode) ? 1 : 0;
unsigned int num_clusters = 0;
......@@ -686,9 +797,16 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
{
u64 o = offset;
u64 s = i_size_read(inode);
zero_len_head = do_div(o, 1 << osb->s_clustersize_bits);
cluster_align_head = !zero_len_head;
zero_len = do_div(o, 1 << osb->s_clustersize_bits);
cluster_align = !zero_len;
zero_len_tail = osb->s_clustersize -
do_div(s, osb->s_clustersize);
if ((offset - i_size_read(inode)) < zero_len_tail)
zero_len_tail = offset - i_size_read(inode);
cluster_align_tail = !zero_len_tail;
}
/*
......@@ -712,10 +830,13 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
goto clean_orphan;
}
/* zeroing out the previously allocated cluster tail
* that but not zeroed */
if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
ret = ocfs2_zero_extend(inode, di_bh, offset);
ret = ocfs2_direct_IO_zero_extend(osb, inode, offset,
zero_len_tail, cluster_align_tail);
else
ret = ocfs2_extend_no_holes(inode, di_bh, offset,
ret = ocfs2_direct_IO_extend_no_holes(osb, inode,
offset);
if (ret < 0) {
mlog_errno(ret);
......@@ -768,7 +889,8 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
mlog_errno(ret);
}
} else if (written > 0 && append_write && !is_overwrite &&
!cluster_align) {
!cluster_align_head) {
/* zeroing out the allocated cluster head */
u32 p_cpos = 0;
u32 v_cpos = ocfs2_bytes_to_clusters(osb->sb, offset);
......@@ -790,7 +912,7 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
ret = blkdev_issue_zeroout(osb->sb->s_bdev,
p_cpos << (osb->s_clustersize_bits - 9),
zero_len >> 9, GFP_NOFS, false);
zero_len_head >> 9, GFP_NOFS, false);
if (ret < 0)
mlog_errno(ret);
......
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