From: Zhang Yi The iomap buffered write path does not hold any locks between querying inode extent mapping information and performing buffered writes. It relies on the sequence counter saved in the inode to detect stale mappings. Commit 07c440e8da8f ("ext4: pass out extent seq counter when mapping blocks") added the m_seq field to ext4_map_blocks to pass out extent sequence numbers, but it missed two callsites within ext4_da_map_blocks(). These callsites are on the delayed allocation path, which is also used in the iomap buffered write path. Pass out the sequence counter to ensure stale mappings can be detected. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara --- fs/ext4/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 6c4d9137b279..39577a6b65b9 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1929,7 +1929,7 @@ static int ext4_da_map_blocks(struct inode *inode, struct ext4_map_blocks *map) ext4_check_map_extents_env(inode); /* Lookup extent status tree firstly */ - if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es, NULL)) { + if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es, &map->m_seq)) { map->m_len = min_t(unsigned int, map->m_len, es.es_len - (map->m_lblk - es.es_lblk)); @@ -1982,7 +1982,7 @@ static int ext4_da_map_blocks(struct inode *inode, struct ext4_map_blocks *map) * is held in write mode, before inserting a new da entry in * the extent status tree. */ - if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es, NULL)) { + if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es, &map->m_seq)) { map->m_len = min_t(unsigned int, map->m_len, es.es_len - (map->m_lblk - es.es_lblk)); -- 2.52.0