nilfs2: relocate io status variables to segment buffer

This moves io status variables in nilfs_write_info struct to
nilfs_segment_buffer struct.

This is a preparation to hide nilfs_write_info in segment buffer code.

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

3 files changed, 44 insertions, 50 deletions

diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c
index c71b689bdbce..d86056ca9a27 100644
--- a/fs/nilfs2/segbuf.c
+++ b/fs/nilfs2/segbuf.c
@@ -63,6 +63,11 @@ struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
         INIT_LIST_HEAD(&segbuf->sb_list);
         INIT_LIST_HEAD(&segbuf->sb_segsum_buffers);
         INIT_LIST_HEAD(&segbuf->sb_payload_buffers);
+
+        init_completion(&segbuf->sb_bio_event);
+        atomic_set(&segbuf->sb_err, 0);
+        segbuf->sb_nbio = 0;
+
         return segbuf;
 }
 
@@ -132,8 +137,6 @@ int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned flags,
         segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary);
         segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0;
         segbuf->sb_sum.ctime = ctime;
-
-        segbuf->sb_io_error = 0;
         return 0;
 }
 
@@ -247,7 +250,7 @@ void nilfs_release_buffers(struct list_head *list)
 static void nilfs_end_bio_write(struct bio *bio, int err)
 {
         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-        struct nilfs_write_info *wi = bio->bi_private;
+        struct nilfs_segment_buffer *segbuf = bio->bi_private;
 
         if (err == -EOPNOTSUPP) {
                 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
@@ -256,21 +259,22 @@ static void nilfs_end_bio_write(struct bio *bio, int err)
         }
 
         if (!uptodate)
-                atomic_inc(&wi->err);
+                atomic_inc(&segbuf->sb_err);
 
         bio_put(bio);
-        complete(&wi->bio_event);
+        complete(&segbuf->sb_bio_event);
 }
 
-static int nilfs_submit_seg_bio(struct nilfs_write_info *wi, int mode)
+static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
+                                   struct nilfs_write_info *wi, int mode)
 {
         struct bio *bio = wi->bio;
         int err;
 
-        if (wi->nbio > 0 && bdi_write_congested(wi->bdi)) {
-                wait_for_completion(&wi->bio_event);
-                wi->nbio--;
-                if (unlikely(atomic_read(&wi->err))) {
+        if (segbuf->sb_nbio > 0 && bdi_write_congested(wi->bdi)) {
+                wait_for_completion(&segbuf->sb_bio_event);
+                segbuf->sb_nbio--;
+                if (unlikely(atomic_read(&segbuf->sb_err))) {
                         bio_put(bio);
                         err = -EIO;
                         goto failed;
@@ -278,7 +282,7 @@ static int nilfs_submit_seg_bio(struct nilfs_write_info *wi, int mode)
         }
 
         bio->bi_end_io = nilfs_end_bio_write;
-        bio->bi_private = wi;
+        bio->bi_private = segbuf;
         bio_get(bio);
         submit_bio(mode, bio);
         if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
@@ -286,7 +290,7 @@ static int nilfs_submit_seg_bio(struct nilfs_write_info *wi, int mode)
                 err = -EOPNOTSUPP;
                 goto failed;
         }
-        wi->nbio++;
+        segbuf->sb_nbio++;
         bio_put(bio);
 
         wi->bio = NULL;
@@ -336,15 +340,12 @@ void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
         wi->max_pages = bio_get_nr_vecs(wi->sb->s_bdev);
         wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
         wi->start = wi->end = 0;
-        wi->nbio = 0;
         wi->blocknr = segbuf->sb_pseg_start;
-
-        atomic_set(&wi->err, 0);
-        init_completion(&wi->bio_event);
 }
 
-static int nilfs_submit_bh(struct nilfs_write_info *wi, struct buffer_head *bh,
-                           int mode)
+static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
+                                  struct nilfs_write_info *wi,
+                                  struct buffer_head *bh, int mode)
 {
         int len, err;
 
@@ -363,7 +364,7 @@ static int nilfs_submit_bh(struct nilfs_write_info *wi, struct buffer_head *bh,
                 return 0;
         }
         /* bio is FULL */
-        err = nilfs_submit_seg_bio(wi, mode);
+        err = nilfs_segbuf_submit_bio(segbuf, wi, mode);
         /* never submit current bh */
         if (likely(!err))
                 goto repeat;
@@ -377,13 +378,13 @@ int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
         int res = 0, rw = WRITE;
 
         list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
-                res = nilfs_submit_bh(wi, bh, rw);
+                res = nilfs_segbuf_submit_bh(segbuf, wi, bh, rw);
                 if (unlikely(res))
                         goto failed_bio;
         }
 
         list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
-                res = nilfs_submit_bh(wi, bh, rw);
+                res = nilfs_segbuf_submit_bh(segbuf, wi, bh, rw);
                 if (unlikely(res))
                         goto failed_bio;
         }
@@ -394,7 +395,7 @@ int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
                  * submission.
                  */
                 rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
-                res = nilfs_submit_seg_bio(wi, rw);
+                res = nilfs_segbuf_submit_bio(segbuf, wi, rw);
         }
 
  failed_bio:
@@ -403,29 +404,27 @@ int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
 
 /**
  * nilfs_segbuf_wait - wait for completion of requested BIOs
- * @wi: nilfs_write_info
+ * @segbuf: segment buffer
  *
  * Return Value: On Success, 0 is returned. On Error, one of the following
  * negative error code is returned.
  *
  * %-EIO - I/O error
  */
-int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf,
-                      struct nilfs_write_info *wi)
+int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
 {
         int err = 0;
 
-        if (!wi->nbio)
+        if (!segbuf->sb_nbio)
                 return 0;
 
         do {
-                wait_for_completion(&wi->bio_event);
-        } while (--wi->nbio > 0);
+                wait_for_completion(&segbuf->sb_bio_event);
+        } while (--segbuf->sb_nbio > 0);
 
-        if (unlikely(atomic_read(&wi->err) > 0)) {
+        if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
                 printk(KERN_ERR "NILFS: IO error writing segment\n");
                 err = -EIO;
-                segbuf->sb_io_error = 1;
         }
         return err;
 }
diff --git a/fs/nilfs2/segbuf.h b/fs/nilfs2/segbuf.h
index 0c3076f4e592..bd076cca37a8 100644
--- a/fs/nilfs2/segbuf.h
+++ b/fs/nilfs2/segbuf.h
@@ -77,7 +77,9 @@ struct nilfs_segsum_info {
  * @sb_rest_blocks: Number of residual blocks in the current segment
  * @sb_segsum_buffers: List of buffers for segment summaries
  * @sb_payload_buffers: List of buffers for segment payload
- * @sb_io_error: I/O error status
+ * @sb_nbio: Number of flying bio requests
+ * @sb_err: I/O error status
+ * @sb_bio_event: Completion event of log writing
  */
 struct nilfs_segment_buffer {
         struct super_block     *sb_super;
@@ -96,7 +98,9 @@ struct nilfs_segment_buffer {
         struct list_head        sb_payload_buffers; /* including super root */
 
         /* io status */
-        int                     sb_io_error;
+        int                     sb_nbio;
+        atomic_t                sb_err;
+        struct completion       sb_bio_event;
 };
 
 #define NILFS_LIST_SEGBUF(head)  \
@@ -177,11 +181,6 @@ struct nilfs_write_info {
         int                     nr_vecs;
         sector_t                blocknr;
 
-        int                     nbio;
-        atomic_t                err;
-        struct completion       bio_event;
-                                /* completion event of segment write */
-
         /*
          * The following fields must be set explicitly
          */
@@ -195,7 +194,6 @@ void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *,
                                 struct nilfs_write_info *);
 int nilfs_segbuf_write(struct nilfs_segment_buffer *,
                        struct nilfs_write_info *);
-int nilfs_segbuf_wait(struct nilfs_segment_buffer *,
-                      struct nilfs_write_info *);
+int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
 
 #endif /* _NILFS_SEGBUF_H */
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 79acf4d66e88..cb004ebe7895 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -1382,14 +1382,14 @@ static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
                                                    struct the_nilfs *nilfs)
 {
         struct nilfs_segment_buffer *segbuf;
-        int ret, done = 0;
+        int ret;
 
         segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
         if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
                 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
                 WARN_ON(ret); /* never fails */
         }
-        if (segbuf->sb_io_error) {
+        if (atomic_read(&segbuf->sb_err)) {
                 /* Case 1: The first segment failed */
                 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
                         /* Case 1a:  Partial segment appended into an existing
@@ -1398,19 +1398,16 @@ static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
                                                 segbuf->sb_fseg_end);
                 else /* Case 1b:  New full segment */
                         set_nilfs_discontinued(nilfs);
-                done++;
         }
 
         list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
                 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
                 WARN_ON(ret); /* never fails */
-                if (!done && segbuf->sb_io_error) {
-                        if (segbuf->sb_segnum != nilfs->ns_nextnum)
-                                /* Case 2: extended segment (!= next) failed */
-                                nilfs_sufile_set_error(nilfs->ns_sufile,
-                                                       segbuf->sb_segnum);
-                        done++;
-                }
+                if (atomic_read(&segbuf->sb_err) &&
+                    segbuf->sb_segnum != nilfs->ns_nextnum)
+                        /* Case 2: extended segment (!= next) failed */
+                        nilfs_sufile_set_error(nilfs->ns_sufile,
+                                               segbuf->sb_segnum);
         }
 }
 
@@ -1801,7 +1798,7 @@ static int nilfs_segctor_write(struct nilfs_sc_info *sci,
                 nilfs_segbuf_prepare_write(segbuf, &wi);
                 err = nilfs_segbuf_write(segbuf, &wi);
 
-                res = nilfs_segbuf_wait(segbuf, &wi);
+                res = nilfs_segbuf_wait(segbuf);
                 err = err ? : res;
                 if (err)
                         return err;