f2fs: introduce FI_ATOMIC_COMMIT

This patch introduces a new flag to indicate inode status of doing atomic
write committing, so that, we can keep atomic write status for inode
during atomic committing, then we can skip GCing pages of atomic write inode,
that avoids random GCed datas being mixed with current transaction, so
isolation of transaction can be kept.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -1977,7 +1977,7 @@ static int f2fs_set_data_page_dirty(struct page *page)
 	if (!PageUptodate(page))
 		SetPageUptodate(page);
 
-	if (f2fs_is_atomic_file(inode)) {
+	if (f2fs_is_atomic_file(inode) && !f2fs_is_commit_atomic_write(inode)) {
 		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
 			register_inmem_page(inode, page);
 			return 1;

fs/f2fs/f2fs.h

@@ -1639,6 +1639,7 @@ enum {
 	FI_UPDATE_WRITE,	/* inode has in-place-update data */
 	FI_NEED_IPU,		/* used for ipu per file */
 	FI_ATOMIC_FILE,		/* indicate atomic file */
+	FI_ATOMIC_COMMIT,	/* indicate the state of atomical committing */
 	FI_VOLATILE_FILE,	/* indicate volatile file */
 	FI_FIRST_BLOCK_WRITTEN,	/* indicate #0 data block was written */
 	FI_DROP_CACHE,		/* drop dirty page cache */
@@ -1828,6 +1829,11 @@ static inline bool f2fs_is_atomic_file(struct inode *inode)
 	return is_inode_flag_set(inode, FI_ATOMIC_FILE);
 }
 
+static inline bool f2fs_is_commit_atomic_write(struct inode *inode)
+{
+	return is_inode_flag_set(inode, FI_ATOMIC_COMMIT);
+}
+
 static inline bool f2fs_is_volatile_file(struct inode *inode)
 {
 	return is_inode_flag_set(inode, FI_VOLATILE_FILE);

fs/f2fs/file.c

@@ -1569,14 +1569,15 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp)
 		goto err_out;
 
 	if (f2fs_is_atomic_file(inode)) {
-		clear_inode_flag(inode, FI_ATOMIC_FILE);
 		ret = commit_inmem_pages(inode);
-		if (ret) {
-			set_inode_flag(inode, FI_ATOMIC_FILE);
+		if (ret)
 			goto err_out;
-		}
+
 		ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true);
-		stat_dec_atomic_write(inode);
+		if (!ret) {
+			clear_inode_flag(inode, FI_ATOMIC_FILE);
+			stat_dec_atomic_write(inode);
+		}
 	} else {
 		ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true);
 	}

fs/f2fs/gc.c

@@ -569,6 +569,9 @@ static void move_encrypted_block(struct inode *inode, block_t bidx,
 	if (!check_valid_map(F2FS_I_SB(inode), segno, off))
 		goto out;
 
+	if (f2fs_is_atomic_file(inode))
+		goto out;
+
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 	err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
 	if (err)
@@ -661,6 +664,9 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
 	if (!check_valid_map(F2FS_I_SB(inode), segno, off))
 		goto out;
 
+	if (f2fs_is_atomic_file(inode))
+		goto out;
+
 	if (gc_type == BG_GC) {
 		if (PageWriteback(page))
 			goto out;

fs/f2fs/segment.c

@@ -242,12 +242,12 @@ void drop_inmem_pages(struct inode *inode)
 {
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 
-	clear_inode_flag(inode, FI_ATOMIC_FILE);
-	stat_dec_atomic_write(inode);
-
 	mutex_lock(&fi->inmem_lock);
 	__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
 	mutex_unlock(&fi->inmem_lock);
+
+	clear_inode_flag(inode, FI_ATOMIC_FILE);
+	stat_dec_atomic_write(inode);
 }
 
 static int __commit_inmem_pages(struct inode *inode,
@@ -316,6 +316,8 @@ int commit_inmem_pages(struct inode *inode)
 	f2fs_balance_fs(sbi, true);
 	f2fs_lock_op(sbi);
 
+	set_inode_flag(inode, FI_ATOMIC_COMMIT);
+
 	mutex_lock(&fi->inmem_lock);
 	err = __commit_inmem_pages(inode, &revoke_list);
 	if (err) {
@@ -337,6 +339,8 @@ int commit_inmem_pages(struct inode *inode)
 	}
 	mutex_unlock(&fi->inmem_lock);
 
+	clear_inode_flag(inode, FI_ATOMIC_COMMIT);
+
 	f2fs_unlock_op(sbi);
 	return err;
 }