nilfs2: add sufile function that can modify multiple segment usages

This is a preparation for the later cleanup patch ("nilfs2: remove
list of freeing segments").

This adds nilfs_sufile_updatev() to sufile, which can modify multiple
segment usages at a time.

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

diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index 98e6867..da12732 100644 (file)
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -18,6 +18,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  *
  * Written by Koji Sato <koji@osrg.net>.
+ * Rivised by Ryusuke Konishi <ryusuke@osrg.net>.
  */
 
 #include <linux/kernel.h>
@@ -108,6 +109,102 @@ static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
        nilfs_mdt_mark_buffer_dirty(header_bh);
 }
 
+/**
+ * nilfs_sufile_updatev - modify multiple segment usages at a time
+ * @sufile: inode of segment usage file
+ * @segnumv: array of segment numbers
+ * @nsegs: size of @segnumv array
+ * @create: creation flag
+ * @ndone: place to store number of modified segments on @segnumv
+ * @dofunc: primitive operation for the update
+ *
+ * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
+ * against the given array of segments.  The @dofunc is called with
+ * buffers of a header block and the sufile block in which the target
+ * segment usage entry is contained.  If @ndone is given, the number
+ * of successfully modified segments from the head is stored in the
+ * place @ndone points to.
+ *
+ * Return Value: On success, zero is returned.  On error, one of the
+ * following negative error codes is returned.
+ *
+ * %-EIO - I/O error.
+ *
+ * %-ENOMEM - Insufficient amount of memory available.
+ *
+ * %-ENOENT - Given segment usage is in hole block (may be returned if
+ *            @create is zero)
+ *
+ * %-EINVAL - Invalid segment usage number
+ */
+int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
+                        int create, size_t *ndone,
+                        void (*dofunc)(struct inode *, __u64,
+                                       struct buffer_head *,
+                                       struct buffer_head *))
+{
+       struct buffer_head *header_bh, *bh;
+       unsigned long blkoff, prev_blkoff;
+       __u64 *seg;
+       size_t nerr = 0, n = 0;
+       int ret = 0;
+
+       if (unlikely(nsegs == 0))
+               goto out;
+
+       down_write(&NILFS_MDT(sufile)->mi_sem);
+       for (seg = segnumv; seg < segnumv + nsegs; seg++) {
+               if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
+                       printk(KERN_WARNING
+                              "%s: invalid segment number: %llu\n", __func__,
+                              (unsigned long long)*seg);
+                       nerr++;
+               }
+       }
+       if (nerr > 0) {
+               ret = -EINVAL;
+               goto out_sem;
+       }
+
+       ret = nilfs_sufile_get_header_block(sufile, &header_bh);
+       if (ret < 0)
+               goto out_sem;
+
+       seg = segnumv;
+       blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
+       ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
+       if (ret < 0)
+               goto out_header;
+
+       for (;;) {
+               dofunc(sufile, *seg, header_bh, bh);
+
+               if (++seg >= segnumv + nsegs)
+                       break;
+               prev_blkoff = blkoff;
+               blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
+               if (blkoff == prev_blkoff)
+                       continue;
+
+               /* get different block */
+               brelse(bh);
+               ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
+               if (unlikely(ret < 0))
+                       goto out_header;
+       }
+       brelse(bh);
+
+ out_header:
+       n = seg - segnumv;
+       brelse(header_bh);
+ out_sem:
+       up_write(&NILFS_MDT(sufile)->mi_sem);
+ out:
+       if (ndone)
+               *ndone = n;
+       return ret;
+}
+
 int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
                        void (*dofunc)(struct inode *, __u64,
                                       struct buffer_head *,

diff --git a/fs/nilfs2/sufile.h b/fs/nilfs2/sufile.h
index a2e2efd..e8e2627 100644 (file)
--- a/fs/nilfs2/sufile.h
+++ b/fs/nilfs2/sufile.h
@@ -46,6 +46,10 @@ int nilfs_sufile_get_ncleansegs(struct inode *, unsigned long *);
 ssize_t nilfs_sufile_get_suinfo(struct inode *, __u64, struct nilfs_suinfo *,
                                size_t);
 
+int nilfs_sufile_updatev(struct inode *, __u64 *, size_t, int, size_t *,
+                        void (*dofunc)(struct inode *, __u64,
+                                       struct buffer_head *,
+                                       struct buffer_head *));
 int nilfs_sufile_update(struct inode *, __u64, int,
                        void (*dofunc)(struct inode *, __u64,
                                       struct buffer_head *,