nilfs2: add nilfs_sufile_set_suinfo to update segment usage
Introduce nilfs_sufile_set_suinfo(), which expects an array of
nilfs_suinfo_update structures and updates the segment usage information
accordingly.
This is basically a helper function for the newly introduced
NILFS_IOCTL_SET_SUINFO ioctl.
[konishi.ryusuke@lab.ntt.co.jp: use put_bh() instead of brelse() because we know bh != NULL]
Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index 3127e9f..5628b99 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -870,6 +870,137 @@
}
/**
+ * nilfs_sufile_set_suinfo - sets segment usage info
+ * @sufile: inode of segment usage file
+ * @buf: array of suinfo_update
+ * @supsz: byte size of suinfo_update
+ * @nsup: size of suinfo_update array
+ *
+ * Description: Takes an array of nilfs_suinfo_update structs and updates
+ * segment usage accordingly. Only the fields indicated by the sup_flags
+ * are updated.
+ *
+ * Return Value: On success, 0 is returned. On error, one of the
+ * following negative error codes is returned.
+ *
+ * %-EIO - I/O error.
+ *
+ * %-ENOMEM - Insufficient amount of memory available.
+ *
+ * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
+ */
+ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
+ unsigned supsz, size_t nsup)
+{
+ struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
+ struct buffer_head *header_bh, *bh;
+ struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
+ struct nilfs_segment_usage *su;
+ void *kaddr;
+ unsigned long blkoff, prev_blkoff;
+ int cleansi, cleansu, dirtysi, dirtysu;
+ long ncleaned = 0, ndirtied = 0;
+ int ret = 0;
+
+ if (unlikely(nsup == 0))
+ return ret;
+
+ for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
+ if (sup->sup_segnum >= nilfs->ns_nsegments
+ || (sup->sup_flags &
+ (~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
+ || (nilfs_suinfo_update_nblocks(sup) &&
+ sup->sup_sui.sui_nblocks >
+ nilfs->ns_blocks_per_segment))
+ return -EINVAL;
+ }
+
+ down_write(&NILFS_MDT(sufile)->mi_sem);
+
+ ret = nilfs_sufile_get_header_block(sufile, &header_bh);
+ if (ret < 0)
+ goto out_sem;
+
+ sup = buf;
+ blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
+ ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
+ if (ret < 0)
+ goto out_header;
+
+ for (;;) {
+ kaddr = kmap_atomic(bh->b_page);
+ su = nilfs_sufile_block_get_segment_usage(
+ sufile, sup->sup_segnum, bh, kaddr);
+
+ if (nilfs_suinfo_update_lastmod(sup))
+ su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
+
+ if (nilfs_suinfo_update_nblocks(sup))
+ su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
+
+ if (nilfs_suinfo_update_flags(sup)) {
+ /*
+ * Active flag is a virtual flag projected by running
+ * nilfs kernel code - drop it not to write it to
+ * disk.
+ */
+ sup->sup_sui.sui_flags &=
+ ~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
+
+ cleansi = nilfs_suinfo_clean(&sup->sup_sui);
+ cleansu = nilfs_segment_usage_clean(su);
+ dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
+ dirtysu = nilfs_segment_usage_dirty(su);
+
+ if (cleansi && !cleansu)
+ ++ncleaned;
+ else if (!cleansi && cleansu)
+ --ncleaned;
+
+ if (dirtysi && !dirtysu)
+ ++ndirtied;
+ else if (!dirtysi && dirtysu)
+ --ndirtied;
+
+ su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
+ }
+
+ kunmap_atomic(kaddr);
+
+ sup = (void *)sup + supsz;
+ if (sup >= supend)
+ break;
+
+ prev_blkoff = blkoff;
+ blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
+ if (blkoff == prev_blkoff)
+ continue;
+
+ /* get different block */
+ mark_buffer_dirty(bh);
+ put_bh(bh);
+ ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
+ if (unlikely(ret < 0))
+ goto out_mark;
+ }
+ mark_buffer_dirty(bh);
+ put_bh(bh);
+
+ out_mark:
+ if (ncleaned || ndirtied) {
+ nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
+ (u64)ndirtied);
+ NILFS_SUI(sufile)->ncleansegs += ncleaned;
+ }
+ nilfs_mdt_mark_dirty(sufile);
+ out_header:
+ put_bh(header_bh);
+ out_sem:
+ up_write(&NILFS_MDT(sufile)->mi_sem);
+ return ret;
+}
+
+/**
* nilfs_sufile_read - read or get sufile inode
* @sb: super block instance
* @susize: size of a segment usage entry