1 files changed, 217 insertions, 104 deletions

diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index 39136637f715..69a5cced1e84 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -28,7 +28,7 @@ nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno)
 {
 	__u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
 
-	do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
+	tcno = div64_ul(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
 	return (unsigned long)tcno;
 }
 
@@ -187,35 +187,90 @@ static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
 }
 
 /**
- * nilfs_cpfile_get_checkpoint - get a checkpoint
- * @cpfile: inode of checkpoint file
- * @cno: checkpoint number
- * @create: create flag
- * @cpp: pointer to a checkpoint
- * @bhp: pointer to a buffer head
- *
- * Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint
- * specified by @cno. A new checkpoint will be created if @cno is the current
- * checkpoint number and @create is nonzero.
- *
- * Return Value: On success, 0 is returned, and the checkpoint and the
- * buffer head of the buffer on which the checkpoint is located are stored in
- * the place pointed by @cpp and @bhp, respectively. On error, one of the
- * following negative error codes is returned.
+ * nilfs_cpfile_read_checkpoint - read a checkpoint entry in cpfile
+ * @cpfile: checkpoint file inode
+ * @cno:    number of checkpoint entry to read
+ * @root:   nilfs root object
+ * @ifile:  ifile's inode to read and attach to @root
  *
- * %-EIO - I/O error.
+ * This function imports checkpoint information from the checkpoint file and
+ * stores it to the inode file given by @ifile and the nilfs root object
+ * given by @root.
  *
- * %-ENOMEM - Insufficient amount of memory available.
+ * Return: 0 on success, or the following negative error code on failure.
+ * * %-EINVAL	- Invalid checkpoint.
+ * * %-ENOMEM	- Insufficient memory available.
+ * * %-EIO	- I/O error (including metadata corruption).
+ */
+int nilfs_cpfile_read_checkpoint(struct inode *cpfile, __u64 cno,
+				 struct nilfs_root *root, struct inode *ifile)
+{
+	struct buffer_head *cp_bh;
+	struct nilfs_checkpoint *cp;
+	void *kaddr;
+	int ret;
+
+	if (cno < 1 || cno > nilfs_mdt_cno(cpfile))
+		return -EINVAL;
+
+	down_read(&NILFS_MDT(cpfile)->mi_sem);
+	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
+	if (unlikely(ret < 0)) {
+		if (ret == -ENOENT)
+			ret = -EINVAL;
+		goto out_sem;
+	}
+
+	kaddr = kmap_local_page(cp_bh->b_page);
+	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
+	if (nilfs_checkpoint_invalid(cp)) {
+		ret = -EINVAL;
+		goto put_cp;
+	}
+
+	ret = nilfs_read_inode_common(ifile, &cp->cp_ifile_inode);
+	if (unlikely(ret)) {
+		/*
+		 * Since this inode is on a checkpoint entry, treat errors
+		 * as metadata corruption.
+		 */
+		nilfs_err(cpfile->i_sb,
+			  "ifile inode (checkpoint number=%llu) corrupted",
+			  (unsigned long long)cno);
+		ret = -EIO;
+		goto put_cp;
+	}
+
+	/* Configure the nilfs root object */
+	atomic64_set(&root->inodes_count, le64_to_cpu(cp->cp_inodes_count));
+	atomic64_set(&root->blocks_count, le64_to_cpu(cp->cp_blocks_count));
+	root->ifile = ifile;
+
+put_cp:
+	kunmap_local(kaddr);
+	brelse(cp_bh);
+out_sem:
+	up_read(&NILFS_MDT(cpfile)->mi_sem);
+	return ret;
+}
+
+/**
+ * nilfs_cpfile_create_checkpoint - create a checkpoint entry on cpfile
+ * @cpfile: checkpoint file inode
+ * @cno:    number of checkpoint to set up
  *
- * %-ENOENT - No such checkpoint.
+ * 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.
  *
- * %-EINVAL - invalid checkpoint.
+ * 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_get_checkpoint(struct inode *cpfile,
-				__u64 cno,
-				int create,
-				struct nilfs_checkpoint **cpp,
-				struct buffer_head **bhp)
+int nilfs_cpfile_create_checkpoint(struct inode *cpfile, __u64 cno)
 {
 	struct buffer_head *header_bh, *cp_bh;
 	struct nilfs_cpfile_header *header;
@@ -223,70 +278,128 @@ int nilfs_cpfile_get_checkpoint(struct inode *cpfile,
 	void *kaddr;
 	int ret;
 
-	if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
-		     (cno < nilfs_mdt_cno(cpfile) && create)))
-		return -EINVAL;
+	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 (ret < 0)
+	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, create, &cp_bh);
-	if (ret < 0)
+	}
+	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 1, &cp_bh);
+	if (unlikely(ret < 0))
 		goto out_header;
-	kaddr = kmap(cp_bh->b_page);
+
+	kaddr = kmap_local_page(cp_bh->b_page);
 	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
 	if (nilfs_checkpoint_invalid(cp)) {
-		if (!create) {
-			kunmap(cp_bh->b_page);
-			brelse(cp_bh);
-			ret = -ENOENT;
-			goto out_header;
-		}
 		/* 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);
-		mark_buffer_dirty(cp_bh);
+		kunmap_local(kaddr);
 
-		kaddr = kmap_atomic(header_bh->b_page);
+		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_atomic(kaddr);
+		kunmap_local(kaddr);
 		mark_buffer_dirty(header_bh);
-		nilfs_mdt_mark_dirty(cpfile);
+	} else {
+		kunmap_local(kaddr);
 	}
 
-	if (cpp != NULL)
-		*cpp = cp;
-	*bhp = cp_bh;
+	/* Force the buffer and the inode to become dirty */
+	mark_buffer_dirty(cp_bh);
+	brelse(cp_bh);
+	nilfs_mdt_mark_dirty(cpfile);
 
- out_header:
+out_header:
 	brelse(header_bh);
 
- out_sem:
+out_sem:
 	up_write(&NILFS_MDT(cpfile)->mi_sem);
 	return ret;
 }
 
 /**
- * nilfs_cpfile_put_checkpoint - put a checkpoint
- * @cpfile: inode of checkpoint file
- * @cno: checkpoint number
- * @bh: buffer head
+ * nilfs_cpfile_finalize_checkpoint - fill in a checkpoint entry in cpfile
+ * @cpfile: checkpoint file inode
+ * @cno:    checkpoint number
+ * @root:   nilfs root object
+ * @blkinc: number of blocks added by this checkpoint
+ * @ctime:  checkpoint creation time
+ * @minor:  minor checkpoint flag
+ *
+ * This function completes the checkpoint entry numbered by @cno in the
+ * cpfile with the data given by the arguments @root, @blkinc, @ctime, and
+ * @minor.
  *
- * Description: nilfs_cpfile_put_checkpoint() releases the checkpoint
- * specified by @cno. @bh must be the buffer head which has been returned by
- * a previous call to nilfs_cpfile_get_checkpoint() with @cno.
+ * Return: 0 on success, or the following negative error code on failure.
+ * * %-ENOMEM	- Insufficient memory available.
+ * * %-EIO	- I/O error (including metadata corruption).
  */
-void nilfs_cpfile_put_checkpoint(struct inode *cpfile, __u64 cno,
-				 struct buffer_head *bh)
+int nilfs_cpfile_finalize_checkpoint(struct inode *cpfile, __u64 cno,
+				     struct nilfs_root *root, __u64 blkinc,
+				     time64_t ctime, bool minor)
 {
-	kunmap(bh->b_page);
-	brelse(bh);
+	struct buffer_head *cp_bh;
+	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_checkpoint_block(cpfile, cno, 0, &cp_bh);
+	if (unlikely(ret < 0)) {
+		if (ret == -ENOENT)
+			goto error;
+		goto out_sem;
+	}
+
+	kaddr = kmap_local_page(cp_bh->b_page);
+	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
+	if (unlikely(nilfs_checkpoint_invalid(cp))) {
+		kunmap_local(kaddr);
+		brelse(cp_bh);
+		goto error;
+	}
+
+	cp->cp_snapshot_list.ssl_next = 0;
+	cp->cp_snapshot_list.ssl_prev = 0;
+	cp->cp_inodes_count = cpu_to_le64(atomic64_read(&root->inodes_count));
+	cp->cp_blocks_count = cpu_to_le64(atomic64_read(&root->blocks_count));
+	cp->cp_nblk_inc = cpu_to_le64(blkinc);
+	cp->cp_create = cpu_to_le64(ctime);
+	cp->cp_cno = cpu_to_le64(cno);
+
+	if (minor)
+		nilfs_checkpoint_set_minor(cp);
+	else
+		nilfs_checkpoint_clear_minor(cp);
+
+	nilfs_write_inode_common(root->ifile, &cp->cp_ifile_inode);
+	nilfs_bmap_write(NILFS_I(root->ifile)->i_bmap, &cp->cp_ifile_inode);
+
+	kunmap_local(kaddr);
+	brelse(cp_bh);
+out_sem:
+	up_write(&NILFS_MDT(cpfile)->mi_sem);
+	return ret;
+
+error:
+	nilfs_error(cpfile->i_sb,
+		    "checkpoint finalization failed due to metadata corruption.");
+	ret = -EIO;
+	goto out_sem;
 }
 
 /**
@@ -347,7 +460,7 @@ int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
 			continue;
 		}
 
-		kaddr = kmap_atomic(cp_bh->b_page);
+		kaddr = kmap_local_page(cp_bh->b_page);
 		cp = nilfs_cpfile_block_get_checkpoint(
 			cpfile, cno, cp_bh, kaddr);
 		nicps = 0;
@@ -369,7 +482,7 @@ int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
 						cpfile, cp_bh, kaddr, nicps);
 				if (count == 0) {
 					/* make hole */
-					kunmap_atomic(kaddr);
+					kunmap_local(kaddr);
 					brelse(cp_bh);
 					ret =
 					  nilfs_cpfile_delete_checkpoint_block(
@@ -384,18 +497,18 @@ int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
 			}
 		}
 
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 		brelse(cp_bh);
 	}
 
 	if (tnicps > 0) {
-		kaddr = kmap_atomic(header_bh->b_page);
+		kaddr = kmap_local_page(header_bh->b_page);
 		header = nilfs_cpfile_block_get_header(cpfile, header_bh,
 						       kaddr);
 		le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
 		mark_buffer_dirty(header_bh);
 		nilfs_mdt_mark_dirty(cpfile);
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 	}
 
 	brelse(header_bh);
@@ -447,7 +560,7 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
 		}
 		ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
 
-		kaddr = kmap_atomic(bh->b_page);
+		kaddr = kmap_local_page(bh->b_page);
 		cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
 		for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
 			if (!nilfs_checkpoint_invalid(cp)) {
@@ -457,7 +570,7 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
 				n++;
 			}
 		}
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 		brelse(bh);
 	}
 
@@ -491,10 +604,10 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
 		ret = nilfs_cpfile_get_header_block(cpfile, &bh);
 		if (ret < 0)
 			goto out;
-		kaddr = kmap_atomic(bh->b_page);
+		kaddr = kmap_local_page(bh->b_page);
 		header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
 		curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 		brelse(bh);
 		if (curr == 0) {
 			ret = 0;
@@ -512,7 +625,7 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
 			ret = 0; /* No snapshots (started from a hole block) */
 		goto out;
 	}
-	kaddr = kmap_atomic(bh->b_page);
+	kaddr = kmap_local_page(bh->b_page);
 	while (n < nci) {
 		cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr);
 		curr = ~(__u64)0; /* Terminator */
@@ -528,7 +641,7 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
 
 		next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
 		if (curr_blkoff != next_blkoff) {
-			kunmap_atomic(kaddr);
+			kunmap_local(kaddr);
 			brelse(bh);
 			ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
 								0, &bh);
@@ -536,12 +649,12 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
 				WARN_ON(ret == -ENOENT);
 				goto out;
 			}
-			kaddr = kmap_atomic(bh->b_page);
+			kaddr = kmap_local_page(bh->b_page);
 		}
 		curr = next;
 		curr_blkoff = next_blkoff;
 	}
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 	brelse(bh);
 	*cnop = curr;
 	ret = n;
@@ -650,24 +763,24 @@ static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
 	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
 	if (ret < 0)
 		goto out_sem;
-	kaddr = kmap_atomic(cp_bh->b_page);
+	kaddr = kmap_local_page(cp_bh->b_page);
 	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
 	if (nilfs_checkpoint_invalid(cp)) {
 		ret = -ENOENT;
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 		goto out_cp;
 	}
 	if (nilfs_checkpoint_snapshot(cp)) {
 		ret = 0;
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 		goto out_cp;
 	}
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
 	ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
 	if (ret < 0)
 		goto out_cp;
-	kaddr = kmap_atomic(header_bh->b_page);
+	kaddr = kmap_local_page(header_bh->b_page);
 	header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
 	list = &header->ch_snapshot_list;
 	curr_bh = header_bh;
@@ -679,13 +792,13 @@ static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
 		prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
 		curr = prev;
 		if (curr_blkoff != prev_blkoff) {
-			kunmap_atomic(kaddr);
+			kunmap_local(kaddr);
 			brelse(curr_bh);
 			ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
 								0, &curr_bh);
 			if (ret < 0)
 				goto out_header;
-			kaddr = kmap_atomic(curr_bh->b_page);
+			kaddr = kmap_local_page(curr_bh->b_page);
 		}
 		curr_blkoff = prev_blkoff;
 		cp = nilfs_cpfile_block_get_checkpoint(
@@ -693,7 +806,7 @@ static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
 		list = &cp->cp_snapshot_list;
 		prev = le64_to_cpu(list->ssl_prev);
 	}
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
 	if (prev != 0) {
 		ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
@@ -705,29 +818,29 @@ static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
 		get_bh(prev_bh);
 	}
 
-	kaddr = kmap_atomic(curr_bh->b_page);
+	kaddr = kmap_local_page(curr_bh->b_page);
 	list = nilfs_cpfile_block_get_snapshot_list(
 		cpfile, curr, curr_bh, kaddr);
 	list->ssl_prev = cpu_to_le64(cno);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
-	kaddr = kmap_atomic(cp_bh->b_page);
+	kaddr = kmap_local_page(cp_bh->b_page);
 	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
 	cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
 	cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
 	nilfs_checkpoint_set_snapshot(cp);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
-	kaddr = kmap_atomic(prev_bh->b_page);
+	kaddr = kmap_local_page(prev_bh->b_page);
 	list = nilfs_cpfile_block_get_snapshot_list(
 		cpfile, prev, prev_bh, kaddr);
 	list->ssl_next = cpu_to_le64(cno);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
-	kaddr = kmap_atomic(header_bh->b_page);
+	kaddr = kmap_local_page(header_bh->b_page);
 	header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
 	le64_add_cpu(&header->ch_nsnapshots, 1);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
 	mark_buffer_dirty(prev_bh);
 	mark_buffer_dirty(curr_bh);
@@ -768,23 +881,23 @@ static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
 	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
 	if (ret < 0)
 		goto out_sem;
-	kaddr = kmap_atomic(cp_bh->b_page);
+	kaddr = kmap_local_page(cp_bh->b_page);
 	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
 	if (nilfs_checkpoint_invalid(cp)) {
 		ret = -ENOENT;
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 		goto out_cp;
 	}
 	if (!nilfs_checkpoint_snapshot(cp)) {
 		ret = 0;
-		kunmap_atomic(kaddr);
+		kunmap_local(kaddr);
 		goto out_cp;
 	}
 
 	list = &cp->cp_snapshot_list;
 	next = le64_to_cpu(list->ssl_next);
 	prev = le64_to_cpu(list->ssl_prev);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
 	ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
 	if (ret < 0)
@@ -808,29 +921,29 @@ static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
 		get_bh(prev_bh);
 	}
 
-	kaddr = kmap_atomic(next_bh->b_page);
+	kaddr = kmap_local_page(next_bh->b_page);
 	list = nilfs_cpfile_block_get_snapshot_list(
 		cpfile, next, next_bh, kaddr);
 	list->ssl_prev = cpu_to_le64(prev);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
-	kaddr = kmap_atomic(prev_bh->b_page);
+	kaddr = kmap_local_page(prev_bh->b_page);
 	list = nilfs_cpfile_block_get_snapshot_list(
 		cpfile, prev, prev_bh, kaddr);
 	list->ssl_next = cpu_to_le64(next);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
-	kaddr = kmap_atomic(cp_bh->b_page);
+	kaddr = kmap_local_page(cp_bh->b_page);
 	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
 	cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
 	cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
 	nilfs_checkpoint_clear_snapshot(cp);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
-	kaddr = kmap_atomic(header_bh->b_page);
+	kaddr = kmap_local_page(header_bh->b_page);
 	header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
 	le64_add_cpu(&header->ch_nsnapshots, -1);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 
 	mark_buffer_dirty(next_bh);
 	mark_buffer_dirty(prev_bh);
@@ -889,13 +1002,13 @@ int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
 	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
 	if (ret < 0)
 		goto out;
-	kaddr = kmap_atomic(bh->b_page);
+	kaddr = kmap_local_page(bh->b_page);
 	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
 	if (nilfs_checkpoint_invalid(cp))
 		ret = -ENOENT;
 	else
 		ret = nilfs_checkpoint_snapshot(cp);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 	brelse(bh);
 
  out:
@@ -972,12 +1085,12 @@ int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
 	ret = nilfs_cpfile_get_header_block(cpfile, &bh);
 	if (ret < 0)
 		goto out_sem;
-	kaddr = kmap_atomic(bh->b_page);
+	kaddr = kmap_local_page(bh->b_page);
 	header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
 	cpstat->cs_cno = nilfs_mdt_cno(cpfile);
 	cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
 	cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 	brelse(bh);
 
  out_sem: