[PATCH 1/3] exfat: add error check when updating dir-entries

[Tetsuhiro Kohada]

Add error check when synchronously updating dir-entries.
Furthermore, add exfat_update_bhs(). It wait for write completion once
instead of sector by sector.

Suggested-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
Signed-off-by: Tetsuhiro Kohada <kohada.t2@xxxxxxxxx>
---
 fs/exfat/dir.c      | 15 +++++++++------
 fs/exfat/exfat_fs.h |  3 ++-
 fs/exfat/file.c     |  5 ++++-
 fs/exfat/inode.c    |  8 +++++---
 fs/exfat/misc.c     | 19 +++++++++++++++++++
 5 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index de43534aa299..3eb8386fb5f2 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -602,16 +602,19 @@ void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
 	es->modified = true;
 }
 
-void exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync)
+int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync)
 {
-	int i;
+	int i, err = 0;
 
-	for (i = 0; i < es->num_bh; i++) {
-		if (es->modified)
-			exfat_update_bh(es->sb, es->bh[i], sync);
-		brelse(es->bh[i]);
+	if (es->modified) {
+		set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(es->sb)->s_state);
+		err = exfat_update_bhs(es->bh, es->num_bh, sync);
 	}
+
+	for (i = 0; i < es->num_bh; i++)
+		err ? bforget(es->bh[i]):brelse(es->bh[i]);
 	kfree(es);
+	return err;
 }
 
 static int exfat_walk_fat_chain(struct super_block *sb,
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 595f3117f492..f4fa0e833486 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -462,7 +462,7 @@ struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
 		int num);
 struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
 		struct exfat_chain *p_dir, int entry, unsigned int type);
-void exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
+int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
 
 /* inode.c */
@@ -515,6 +515,7 @@ void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
 u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
 u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
 void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync);
+int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync);
 void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
 		unsigned int size, unsigned char flags);
 void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec);
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index fce03f318787..37c8f04c1f8a 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -153,6 +153,7 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 		struct timespec64 ts;
 		struct exfat_dentry *ep, *ep2;
 		struct exfat_entry_set_cache *es;
+		int err;
 
 		es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
 				ES_ALL_ENTRIES);
@@ -187,7 +188,9 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 		}
 
 		exfat_update_dir_chksum_with_entry_set(es);
-		exfat_free_dentry_set(es, inode_needs_sync(inode));
+		err = exfat_free_dentry_set(es, inode_needs_sync(inode));
+		if (err)
+			return err;
 	}
 
 	/* cut off from the FAT chain */
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index ef7cf7a6d187..c0bfd1a586aa 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -77,8 +77,7 @@ static int __exfat_write_inode(struct inode *inode, int sync)
 	ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
 
 	exfat_update_dir_chksum_with_entry_set(es);
-	exfat_free_dentry_set(es, sync);
-	return 0;
+	return exfat_free_dentry_set(es, sync);
 }
 
 int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
@@ -222,6 +221,7 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 		if (ei->dir.dir != DIR_DELETED && modified) {
 			struct exfat_dentry *ep;
 			struct exfat_entry_set_cache *es;
+			int err;
 
 			es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
 				ES_ALL_ENTRIES);
@@ -240,7 +240,9 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 				ep->dentry.stream.valid_size;
 
 			exfat_update_dir_chksum_with_entry_set(es);
-			exfat_free_dentry_set(es, inode_needs_sync(inode));
+			err = exfat_free_dentry_set(es, inode_needs_sync(inode));
+			if (err)
+				return err;
 
 		} /* end of if != DIR_DELETED */
 
diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c
index 17d41f3d3709..dc34968e99d3 100644
--- a/fs/exfat/misc.c
+++ b/fs/exfat/misc.c
@@ -173,6 +173,25 @@ void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync)
 		sync_dirty_buffer(bh);
 }
 
+int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync)
+{
+	int i, err = 0;
+
+	for (i = 0; i < nr_bhs; i++) {
+		set_buffer_uptodate(bhs[i]);
+		mark_buffer_dirty(bhs[i]);
+		if (sync)
+			write_dirty_buffer(bhs[i], 0);
+	}
+
+	for (i = 0; i < nr_bhs && sync; i++) {
+		wait_on_buffer(bhs[i]);
+		if (!buffer_uptodate(bhs[i]))
+			err = -EIO;
+	}
+	return err;
+}
+
 void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
 		unsigned int size, unsigned char flags)
 {
-- 
2.25.1