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Ocfs2/move_extents: defrag a range of extent.

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It's a relatively complete function to accomplish defragmentation for entire
or partial extent, one journal handle was kept during the operation, it was
logically doing one more thing than ocfs2_move_extent() acutally, yes, it's
claiming the new clusters itself;-)

Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
This commit is contained in:
Tristan Ye 2011-03-18 14:35:34 +08:00
parent 8f603e567a
commit 202ee5facb
1 changed files with 136 additions and 0 deletions
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136
fs/ocfs2/move_extents.c
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@ -215,3 +215,139 @@ out:
return ret;
}
/*
* Using one journal handle to guarantee the data consistency in case
* crash happens anywhere.
*/
static int ocfs2_defrag_extent(struct ocfs2_move_extents_context *context,
u32 cpos, u32 phys_cpos, u32 len, int ext_flags)
{
int ret, credits = 0, extra_blocks = 0;
handle_t *handle;
struct inode *inode = context->inode;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct inode *tl_inode = osb->osb_tl_inode;
struct ocfs2_refcount_tree *ref_tree = NULL;
u32 new_phys_cpos, new_len;
u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
if ((ext_flags & OCFS2_EXT_REFCOUNTED) && len) {
BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &
OCFS2_HAS_REFCOUNT_FL));
BUG_ON(!context->refcount_loc);
ret = ocfs2_lock_refcount_tree(osb, context->refcount_loc, 1,
&ref_tree, NULL);
if (ret) {
mlog_errno(ret);
return ret;
}
ret = ocfs2_prepare_refcount_change_for_del(inode,
context->refcount_loc,
phys_blkno,
len,
&credits,
&extra_blocks);
if (ret) {
mlog_errno(ret);
goto out;
}
}
ret = ocfs2_lock_allocators_move_extents(inode, &context->et, len, 1,
&context->meta_ac,
&context->data_ac,
extra_blocks, &credits);
if (ret) {
mlog_errno(ret);
goto out;
}
/*
* should be using allocation reservation strategy there?
*
* if (context->data_ac)
* context->data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
*/
mutex_lock(&tl_inode->i_mutex);
if (ocfs2_truncate_log_needs_flush(osb)) {
ret = __ocfs2_flush_truncate_log(osb);
if (ret < 0) {
mlog_errno(ret);
goto out_unlock_mutex;
}
}
handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out_unlock_mutex;
}
ret = __ocfs2_claim_clusters(handle, context->data_ac, 1, len,
&new_phys_cpos, &new_len);
if (ret) {
mlog_errno(ret);
goto out_commit;
}
/*
* we're not quite patient here to make multiple attempts for claiming
* enough clusters, failure to claim clusters per-requested is not a
* disaster though, it can only mean partial range of defragmentation
* or extent movements gets gone, users anyway is able to have another
* try as they wish anytime, since they're going to be returned a
* '-ENOSPC' and completed length of this movement.
*/
if (new_len != len) {
mlog(0, "len_claimed: %u, len: %u\n", new_len, len);
context->range->me_flags &= ~OCFS2_MOVE_EXT_FL_COMPLETE;
ret = -ENOSPC;
goto out_commit;
}
mlog(0, "cpos: %u, phys_cpos: %u, new_phys_cpos: %u\n", cpos,
phys_cpos, new_phys_cpos);
ret = __ocfs2_move_extent(handle, context, cpos, len, phys_cpos,
new_phys_cpos, ext_flags);
if (ret)
mlog_errno(ret);
/*
* Here we should write the new page out first if we are
* in write-back mode.
*/
ret = ocfs2_cow_sync_writeback(inode->i_sb, context->inode, cpos, len);
if (ret)
mlog_errno(ret);
out_commit:
ocfs2_commit_trans(osb, handle);
out_unlock_mutex:
mutex_unlock(&tl_inode->i_mutex);
if (context->data_ac) {
ocfs2_free_alloc_context(context->data_ac);
context->data_ac = NULL;
}
if (context->meta_ac) {
ocfs2_free_alloc_context(context->meta_ac);
context->meta_ac = NULL;
}
out:
if (ref_tree)
ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
return ret;
}