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
--- 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 @@
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 *,