[Ocfs2-devel] [PATCH 1/3] ocfs2: Add ocfs2_trim_fs for SSD trim support.
Tao Ma
tm at tao.ma
Mon May 9 20:14:05 PDT 2011
Hi Sunil,
Thanks for the review.
On 05/10/2011 07:02 AM, Sunil Mushran wrote:
> On 05/06/2011 02:27 AM, Tao Ma wrote:
>> From: Tao Ma<boyu.mt at taobao.com>
>>
>> Add ocfs2_trim_fs to support trimming freed clusters in the
>> volume. A range will be given and all the freed clusters greater
>> than minlen will be discarded to the block layer.
>>
>> Signed-off-by: Tao Ma<boyu.mt at taobao.com>
>> ---
>> fs/ocfs2/alloc.c | 156
>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/ocfs2/alloc.h | 1 +
>> 2 files changed, 157 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
>> index 48aa9c7..93a3f92 100644
>> --- a/fs/ocfs2/alloc.c
>> +++ b/fs/ocfs2/alloc.c
>> @@ -29,6 +29,7 @@
>> #include<linux/highmem.h>
>> #include<linux/swap.h>
>> #include<linux/quotaops.h>
>> +#include<linux/blkdev.h>
>>
>> #include<cluster/masklog.h>
>>
>> @@ -7184,3 +7185,158 @@ out_commit:
>> out:
>> return ret;
>> }
>> +
>> +static int ocfs2_trim_extent(struct super_block *sb,
>> + struct ocfs2_group_desc *gd,
>> + int start, int count)
>
> u32 will be better for start and count.
>
>> +{
>> + u64 discard;
>> +
>> + count = ocfs2_clusters_to_blocks(sb, count);
>
> ocfs2_clusters_to_blocks() returns u64.
fine. Actually my original thought was that both 'start' and 'count' are
within the range of a group. So it shouldn't be that much. But if you
prefer, I will change it.
>
>> + discard = le64_to_cpu(gd->bg_blkno) +
>> + ocfs2_clusters_to_blocks(sb, start);
>> +
>> + return sb_issue_discard(sb, discard, count, GFP_NOFS, 0);
>
>> +}
>> +
>> +static int ocfs2_trim_group(struct super_block *sb,
>> + struct ocfs2_group_desc *gd,
>> + int start, int max, int minbits)
>> +{
>> + int ret = 0, count = 0, next;
>> + void *bitmap = gd->bg_bitmap;
>> +
>> + while (start< max) {
>> + start = ocfs2_find_next_zero_bit(bitmap, max, start);
>> + if (start>= max)
>> + break;
>> + next = ocfs2_find_next_bit(bitmap, max, start);
>> +
>> + if ((next - start)>= minbits) {
>> + ret = ocfs2_trim_extent(sb, gd,
>> + start, next - start);
>> + if (ret< 0) {
>> + mlog_errno(ret);
>> + break;
>> + }
>> + count += next - start;
>> + }
>> + start = next + 1;
>> +
>> + if (fatal_signal_pending(current)) {
>> + count = -ERESTARTSYS;
>> + break;
>> + }
>> +
>> + if ((le16_to_cpu(gd->bg_free_bits_count) - count)< minbits)
>> + break;
>
> This check could also be done earlier.
oh, yes, I will add it. Thanks.
>
>> + }
>> +
>> + if (ret< 0)
>> + count = ret;
>> +
>> + return count;
>> +}
>> +
>> +int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range)
>> +{
>> + struct ocfs2_super *osb = OCFS2_SB(sb);
>> + u64 start, len, minlen, trimmed, first_group, last_group, group;
>> + int ret, cnt, first_bit, last_bit;
>> + struct buffer_head *main_bm_bh = NULL;
>> + struct inode *main_bm_inode = NULL;
>> + struct buffer_head *gd_bh = NULL;
>> + struct ocfs2_dinode *main_bm;
>> + struct ocfs2_group_desc *gd = NULL;
>> +
>> + start = range->start>> osb->s_clustersize_bits;
>> + len = range->len>> osb->s_clustersize_bits;
>> + minlen = range->minlen>> osb->s_clustersize_bits;
>> + trimmed = 0;
>> +
>> + if (!len) {
>> + range->len = 0;
>> + return 0;
>> + }
>> +
>> + if (minlen>= osb->bitmap_cpg)
>> + return -EINVAL;
>> +
>> + main_bm_inode = ocfs2_get_system_file_inode(osb,
>> + GLOBAL_BITMAP_SYSTEM_INODE,
>> + OCFS2_INVALID_SLOT);
>> + if (!main_bm_inode) {
>> + ret = -EIO;
>> + mlog_errno(ret);
>> + goto out;
>> + }
>> +
>> + mutex_lock(&main_bm_inode->i_mutex);
>> +
>> + ret = ocfs2_inode_lock(main_bm_inode,&main_bm_bh, 0);
>> + if (ret< 0) {
>> + mlog_errno(ret);
>> + goto out_mutex;
>> + }
>> + main_bm = (struct ocfs2_dinode *)main_bm_bh->b_data;
>> +
>> + if (start>= le32_to_cpu(main_bm->i_clusters)) {
>> + ret = -EINVAL;
>> + mlog_errno(ret);
>
> User error. No need to log it.
yeah, thanks for the advice.
Regards,
Tao
>
>> + goto out_unlock;
>> + }
>> +
>> + if (start + len> le32_to_cpu(main_bm->i_clusters))
>> + len = le32_to_cpu(main_bm->i_clusters) - start;
>> +
>> + /* Determine first and last group to examine based on start and
>> len */
>> + first_group = ocfs2_which_cluster_group(main_bm_inode, start);
>> + if (first_group == osb->first_cluster_group_blkno)
>> + first_bit = start;
>> + else
>> + first_bit = start - ocfs2_blocks_to_clusters(sb, first_group);
>> + last_group = ocfs2_which_cluster_group(main_bm_inode, start + len
>> - 1);
>> + last_bit = osb->bitmap_cpg;
>> +
>> + for (group = first_group; group<= last_group;) {
>> + if (first_bit + len>= osb->bitmap_cpg)
>> + last_bit = osb->bitmap_cpg;
>> + else
>> + last_bit = first_bit + len;
>> +
>> + ret = ocfs2_read_group_descriptor(main_bm_inode,
>> + main_bm, group,
>> + &gd_bh);
>> + if (ret< 0) {
>> + mlog_errno(ret);
>> + break;
>> + }
>> +
>> + gd = (struct ocfs2_group_desc *)gd_bh->b_data;
>> + cnt = ocfs2_trim_group(sb, gd, first_bit, last_bit, minlen);
>> + brelse(gd_bh);
>> + gd_bh = NULL;
>> + if (cnt< 0) {
>> + ret = cnt;
>> + mlog_errno(ret);
>> + break;
>> + }
>> +
>> + trimmed += cnt;
>> + len -= osb->bitmap_cpg - first_bit;
>> + first_bit = 0;
>> + if (group == osb->first_cluster_group_blkno)
>> + group = ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
>> + else
>> + group += ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
>> + }
>> + range->len = trimmed * sb->s_blocksize;
>> +out_unlock:
>> + ocfs2_inode_unlock(main_bm_inode, 0);
>> + brelse(main_bm_bh);
>> +out_mutex:
>> + mutex_unlock(&main_bm_inode->i_mutex);
>> + iput(main_bm_inode);
>> +out:
>> + return ret;
>> +}
>> diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h
>> index 3bd08a0..ca381c5 100644
>> --- a/fs/ocfs2/alloc.h
>> +++ b/fs/ocfs2/alloc.h
>> @@ -239,6 +239,7 @@ int ocfs2_find_leaf(struct ocfs2_caching_info *ci,
>> struct buffer_head **leaf_bh);
>> int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32
>> v_cluster);
>>
>> +int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range);
>> /*
>> * Helper function to look at the # of clusters in an extent record.
>> */
>
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