nilfs2: localize highmem mapping for checkpoint creation within cpfile

[linux-2.6-microblaze.git] / fs / nilfs2 / cpfile.c

diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index 3913663..f62da80 100644 (file)
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -272,6 +272,80 @@ int nilfs_cpfile_get_checkpoint(struct inode *cpfile,
        return ret;
 }
 
+/**
+ * nilfs_cpfile_create_checkpoint - create a checkpoint entry on cpfile
+ * @cpfile: checkpoint file inode
+ * @cno:    number of checkpoint to set up
+ *
+ * This function creates a checkpoint with the number specified by @cno on
+ * cpfile.  If the specified checkpoint entry already exists due to a past
+ * failure, it will be reused without returning an error.
+ * In either case, the buffer of the block containing the checkpoint entry
+ * and the cpfile inode are made dirty for inclusion in the write log.
+ *
+ * Return: 0 on success, or the following negative error code on failure.
+ * * %-ENOMEM  - Insufficient memory available.
+ * * %-EIO     - I/O error (including metadata corruption).
+ * * %-EROFS   - Read only filesystem
+ */
+int nilfs_cpfile_create_checkpoint(struct inode *cpfile, __u64 cno)
+{
+       struct buffer_head *header_bh, *cp_bh;
+       struct nilfs_cpfile_header *header;
+       struct nilfs_checkpoint *cp;
+       void *kaddr;
+       int ret;
+
+       if (WARN_ON_ONCE(cno < 1))
+               return -EIO;
+
+       down_write(&NILFS_MDT(cpfile)->mi_sem);
+       ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
+       if (unlikely(ret < 0)) {
+               if (ret == -ENOENT) {
+                       nilfs_error(cpfile->i_sb,
+                                   "checkpoint creation failed due to metadata corruption.");
+                       ret = -EIO;
+               }
+               goto out_sem;
+       }
+       ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 1, &cp_bh);
+       if (unlikely(ret < 0))
+               goto out_header;
+
+       kaddr = kmap_local_page(cp_bh->b_page);
+       cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
+       if (nilfs_checkpoint_invalid(cp)) {
+               /* a newly-created checkpoint */
+               nilfs_checkpoint_clear_invalid(cp);
+               if (!nilfs_cpfile_is_in_first(cpfile, cno))
+                       nilfs_cpfile_block_add_valid_checkpoints(cpfile, cp_bh,
+                                                                kaddr, 1);
+               kunmap_local(kaddr);
+
+               kaddr = kmap_local_page(header_bh->b_page);
+               header = nilfs_cpfile_block_get_header(cpfile, header_bh,
+                                                      kaddr);
+               le64_add_cpu(&header->ch_ncheckpoints, 1);
+               kunmap_local(kaddr);
+               mark_buffer_dirty(header_bh);
+       } else {
+               kunmap_local(kaddr);
+       }
+
+       /* Force the buffer and the inode to become dirty */
+       mark_buffer_dirty(cp_bh);
+       brelse(cp_bh);
+       nilfs_mdt_mark_dirty(cpfile);
+
+out_header:
+       brelse(header_bh);
+
+out_sem:
+       up_write(&NILFS_MDT(cpfile)->mi_sem);
+       return ret;
+}
+
 /**
  * nilfs_cpfile_put_checkpoint - put a checkpoint
  * @cpfile: inode of checkpoint file