Under writeback mode, inode->i_blocks is not updated, making utils like du read st.blocks as 0. For example, when using virtiofs (cache=always & nondax mode) with writeback_cache enabled, writing a new file and check its disk usage with du, du reports 0 usage. # uname -r 5.6.0-rc6+ # mount -t virtiofs virtiofs /mnt/virtiofs # rm -f /mnt/virtiofs/testfile # create new file and do extend write # xfs_io -fc "pwrite 0 4k" /mnt/virtiofs/testfile wrote 4096/4096 bytes at offset 0 4 KiB, 1 ops; 0.0001 sec (28.103 MiB/sec and 7194.2446 ops/sec) # stat -c %s,%b /mnt/virtiofs/testfile 4096,0 <==== i_size is correct, but block usage is 0 Fix it by invalidating attr in fuse_write_end(), like other write paths. Signed-off-by: Eryu Guan <eguan@xxxxxxxxxxxxxxxxx> --- fs/fuse/file.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 9d67b830fb7a..3c875104ca11 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -2228,6 +2228,7 @@ static int fuse_write_end(struct file *file, struct address_space *mapping, } fuse_write_update_size(inode, pos + copied); + fuse_invalidate_attr(inode); set_page_dirty(page); unlock: -- 1.8.3.1
