nilfs2: move routine to set segment usage into sufile

This adds nilfs_sufile_set_segment_usage() function in sufile to
replace direct access to the sufile metadata in log writer code.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

3 files changed, 49 insertions, 22 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 3ae4a3849f81..097f9c467fef 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -1457,21 +1457,16 @@ static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
                                           struct inode *sufile)
 {
         struct nilfs_segment_buffer *segbuf;
-        struct buffer_head *bh_su;
-        struct nilfs_segment_usage *raw_su;
         unsigned long live_blocks;
         int ret;
 
         list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
-                ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
-                                                     &raw_su, &bh_su);
-                WARN_ON(ret); /* always succeed because bh_su is dirty */
                 live_blocks = segbuf->sb_sum.nblocks +
                         (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
-                raw_su->su_lastmod = cpu_to_le64(sci->sc_seg_ctime);
-                raw_su->su_nblocks = cpu_to_le32(live_blocks);
-                nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
-                                               bh_su);
+                ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
+                                                     live_blocks,
+                                                     sci->sc_seg_ctime);
+                WARN_ON(ret); /* always succeed because the segusage is dirty */
         }
 }
 
@@ -1479,25 +1474,18 @@ static void nilfs_segctor_cancel_segusage(struct nilfs_sc_info *sci,
                                           struct inode *sufile)
 {
         struct nilfs_segment_buffer *segbuf;
-        struct buffer_head *bh_su;
-        struct nilfs_segment_usage *raw_su;
         int ret;
 
         segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
-        ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
-                                             &raw_su, &bh_su);
-        WARN_ON(ret); /* always succeed because bh_su is dirty */
-        raw_su->su_nblocks = cpu_to_le32(segbuf->sb_pseg_start -
-                                         segbuf->sb_fseg_start);
-        nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum, bh_su);
+        ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
+                                             segbuf->sb_pseg_start -
+                                             segbuf->sb_fseg_start, 0);
+        WARN_ON(ret); /* always succeed because the segusage is dirty */
 
         list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
-                ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
-                                                     &raw_su, &bh_su);
+                ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
+                                                     0, 0);
                 WARN_ON(ret); /* always succeed */
-                raw_su->su_nblocks = 0;
-                nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
-                                               bh_su);
         }
 }
 
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index d560f882a868..3eed998df1c8 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -521,6 +521,43 @@ int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
 }
 
 /**
+ * nilfs_sufile_set_segment_usage - set usage of a segment
+ * @sufile: inode of segment usage file
+ * @segnum: segment number
+ * @nblocks: number of live blocks in the segment
+ * @modtime: modification time (option)
+ */
+int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
+                                   unsigned long nblocks, time_t modtime)
+{
+        struct buffer_head *bh;
+        struct nilfs_segment_usage *su;
+        void *kaddr;
+        int ret;
+
+        down_write(&NILFS_MDT(sufile)->mi_sem);
+        ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
+        if (ret < 0)
+                goto out_sem;
+
+        kaddr = kmap_atomic(bh->b_page, KM_USER0);
+        su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
+        WARN_ON(nilfs_segment_usage_error(su));
+        if (modtime)
+                su->su_lastmod = cpu_to_le64(modtime);
+        su->su_nblocks = cpu_to_le32(nblocks);
+        kunmap_atomic(kaddr, KM_USER0);
+
+        nilfs_mdt_mark_buffer_dirty(bh);
+        nilfs_mdt_mark_dirty(sufile);
+        brelse(bh);
+
+ out_sem:
+        up_write(&NILFS_MDT(sufile)->mi_sem);
+        return ret;
+}
+
+/**
  * nilfs_sufile_get_stat - get segment usage statistics
  * @sufile: inode of segment usage file
  * @stat: pointer to a structure of segment usage statistics
diff --git a/fs/nilfs2/sufile.h b/fs/nilfs2/sufile.h
index 4146a652aed1..e1186bf3b964 100644
--- a/fs/nilfs2/sufile.h
+++ b/fs/nilfs2/sufile.h
@@ -43,6 +43,8 @@ int nilfs_sufile_get_segment_usage(struct inode *, __u64,
 void nilfs_sufile_put_segment_usage(struct inode *, __u64,
                                     struct buffer_head *);
 int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum);
+int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
+                                   unsigned long nblocks, time_t modtime);
 int nilfs_sufile_get_stat(struct inode *, struct nilfs_sustat *);
 ssize_t nilfs_sufile_get_suinfo(struct inode *, __u64, void *, unsigned,
                                 size_t);