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ocfs2: CoW a reflinked cluster when it is truncated.

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When we truncate a file to a specific size which resides in a reflinked
cluster, we need to CoW it since ocfs2_zero_range_for_truncate will
zero the space after the size(just another type of write).

So we add a "max_cpos" in ocfs2_refcount_cow so that it will stop when
it hit the max cluster offset.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
This commit is contained in:
Tao Ma
2009-08-26 09:47:28 +08:00
committed by Joel Becker
parent 293b2f70b4
commit 37f8a2bfaa
4 changed files with 70 additions and 14 deletions
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46
fs/ocfs2/file.c
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@ -335,6 +335,39 @@ out:
return ret;
}
static int ocfs2_cow_file_pos(struct inode *inode,
struct buffer_head *fe_bh,
u64 offset)
{
int status;
u32 phys, cpos = offset >> OCFS2_SB(inode->i_sb)->s_clustersize_bits;
unsigned int num_clusters = 0;
unsigned int ext_flags = 0;
/*
* If the new offset is aligned to the range of the cluster, there is
* no space for ocfs2_zero_range_for_truncate to fill, so no need to
* CoW either.
*/
if ((offset & (OCFS2_SB(inode->i_sb)->s_clustersize - 1)) == 0)
return 0;
status = ocfs2_get_clusters(inode, cpos, &phys,
&num_clusters, &ext_flags);
if (status) {
mlog_errno(status);
goto out;
}
if (!(ext_flags & OCFS2_EXT_REFCOUNTED))
goto out;
return ocfs2_refcount_cow(inode, fe_bh, cpos, 1, cpos+1);
out:
return status;
}
static int ocfs2_orphan_for_truncate(struct ocfs2_super *osb,
struct inode *inode,
struct buffer_head *fe_bh,
@ -347,6 +380,17 @@ static int ocfs2_orphan_for_truncate(struct ocfs2_super *osb,
mlog_entry_void();
/*
* We need to CoW the cluster contains the offset if it is reflinked
* since we will call ocfs2_zero_range_for_truncate later which will
* write "0" from offset to the end of the cluster.
*/
status = ocfs2_cow_file_pos(inode, fe_bh, new_i_size);
if (status) {
mlog_errno(status);
return status;
}
/* TODO: This needs to actually orphan the inode in this
* transaction. */
@ -1713,7 +1757,7 @@ static int ocfs2_prepare_inode_for_refcount(struct inode *inode,
*meta_level = 1;
ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters);
ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters, UINT_MAX);
if (ret)
mlog_errno(ret);
out: