提交 37f8a2bf 编写于 作者: T Tao Ma 提交者: Joel Becker

ocfs2: CoW a reflinked cluster when it is truncated.

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: NTao Ma <tao.ma@oracle.com>
上级 293b2f70
......@@ -1712,7 +1712,7 @@ int ocfs2_write_begin_nolock(struct address_space *mapping,
goto out;
} else if (ret == 1) {
ret = ocfs2_refcount_cow(inode, di_bh,
wc->w_cpos, wc->w_clen);
wc->w_cpos, wc->w_clen, UINT_MAX);
if (ret) {
mlog_errno(ret);
goto out;
......
......@@ -335,6 +335,39 @@ int ocfs2_simple_size_update(struct inode *inode,
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:
......
......@@ -2482,6 +2482,7 @@ static inline unsigned int ocfs2_cow_align_length(struct super_block *sb,
*
* cpos is vitual start cluster position we want to do CoW in a
* file and write_len is the cluster length.
* max_cpos is the place where we want to stop CoW intentionally.
*
* Normal we will start CoW from the beginning of extent record cotaining cpos.
* We try to break up extents on boundaries of MAX_CONTIG_BYTES so that we
......@@ -2491,6 +2492,7 @@ static int ocfs2_refcount_cal_cow_clusters(struct inode *inode,
struct buffer_head *di_bh,
u32 cpos,
u32 write_len,
u32 max_cpos,
u32 *cow_start,
u32 *cow_len)
{
......@@ -2505,6 +2507,8 @@ static int ocfs2_refcount_cal_cow_clusters(struct inode *inode,
int contig_clusters = ocfs2_cow_contig_clusters(inode->i_sb);
int leaf_clusters;
BUG_ON(cpos + write_len > max_cpos);
if (tree_height > 0) {
ret = ocfs2_find_leaf(INODE_CACHE(inode), el, cpos, &eb_bh);
if (ret) {
......@@ -2549,15 +2553,20 @@ static int ocfs2_refcount_cal_cow_clusters(struct inode *inode,
}
/*
* If we encounter a hole or a non-refcounted record,
* stop the search.
* If we encounter a hole, a non-refcounted record or
* pass the max_cpos, stop the search.
*/
if ((!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) ||
(*cow_len && rec_end != le32_to_cpu(rec->e_cpos)))
(*cow_len && rec_end != le32_to_cpu(rec->e_cpos)) ||
(max_cpos <= le32_to_cpu(rec->e_cpos)))
break;
leaf_clusters = le16_to_cpu(rec->e_leaf_clusters);
rec_end = le32_to_cpu(rec->e_cpos) + leaf_clusters;
if (rec_end > max_cpos) {
rec_end = max_cpos;
leaf_clusters = rec_end - le32_to_cpu(rec->e_cpos);
}
/*
* How many clusters do we actually need from
......@@ -3184,12 +3193,13 @@ static int ocfs2_replace_cow(struct inode *inode,
}
/*
* Starting at cpos, try to CoW write_len clusters.
* This will stop when it runs into a hole or an unrefcounted extent.
* Starting at cpos, try to CoW write_len clusters. Don't CoW
* past max_cpos. This will stop when it runs into a hole or an
* unrefcounted extent.
*/
static int ocfs2_refcount_cow_hunk(struct inode *inode,
struct buffer_head *di_bh,
u32 cpos, u32 write_len)
u32 cpos, u32 write_len, u32 max_cpos)
{
int ret;
u32 cow_start = 0, cow_len = 0;
......@@ -3201,12 +3211,14 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
ret = ocfs2_refcount_cal_cow_clusters(inode, di_bh, cpos, write_len,
ret = ocfs2_refcount_cal_cow_clusters(inode, di_bh,
cpos, write_len, max_cpos,
&cow_start, &cow_len);
if (ret) {
mlog_errno(ret);
goto out;
}
mlog(0, "CoW inode %lu, cpos %u, write_len %u, cow_start %u, "
"cow_len %u\n", inode->i_ino,
cpos, write_len, cow_start, cow_len);
......@@ -3233,12 +3245,12 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
/*
* CoW any and all clusters between cpos and cpos+write_len.
* If this returns successfully, all clusters between cpos and
* cpos+write_len are safe to modify.
* Don't CoW past max_cpos. If this returns successfully, all
* clusters between cpos and cpos+write_len are safe to modify.
*/
int ocfs2_refcount_cow(struct inode *inode,
struct buffer_head *di_bh,
u32 cpos, u32 write_len)
u32 cpos, u32 write_len, u32 max_cpos)
{
int ret = 0;
u32 p_cluster, num_clusters;
......@@ -3257,7 +3269,7 @@ int ocfs2_refcount_cow(struct inode *inode,
if (ext_flags & OCFS2_EXT_REFCOUNTED) {
ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
num_clusters);
num_clusters, max_cpos);
if (ret) {
mlog_errno(ret);
break;
......
......@@ -53,5 +53,5 @@ int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
int *credits,
struct ocfs2_alloc_context **meta_ac);
int ocfs2_refcount_cow(struct inode *inode, struct buffer_head *di_bh,
u32 cpos, u32 write_len);
u32 cpos, u32 write_len, u32 max_cpos);
#endif /* OCFS2_REFCOUNTTREE_H */
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