From: Andiry Xu <jix...@cs.ucsd.edu> NOVA persists file metadata and data before returning to the user space. Hence, fsync is a no-op if the file is not mmaped.
Signed-off-by: Andiry Xu <jix...@cs.ucsd.edu> --- fs/nova/file.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/fs/nova/file.c b/fs/nova/file.c index ecaf20a..f60fdf3 100644 --- a/fs/nova/file.c +++ b/fs/nova/file.c @@ -66,9 +66,59 @@ static loff_t nova_llseek(struct file *file, loff_t offset, int origin) return offset; } +/* This function is called by both msync() and fsync(). + * TODO: Check if we can avoid calling nova_flush_buffer() for fsync. We use + * movnti to write data to files, so we may want to avoid doing unnecessary + * nova_flush_buffer() on fsync() + */ +static int nova_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct address_space *mapping = file->f_mapping; + unsigned long start_pgoff, end_pgoff; + int ret = 0; + timing_t fsync_time; + + NOVA_START_TIMING(fsync_t, fsync_time); + + if (datasync) + NOVA_STATS_ADD(fdatasync, 1); + + /* No need to flush if the file is not mmaped */ + if (!mapping_mapped(mapping)) + goto persist; + + start_pgoff = start >> PAGE_SHIFT; + end_pgoff = (end + 1) >> PAGE_SHIFT; + nova_dbgv("%s: msync pgoff range %lu to %lu\n", + __func__, start_pgoff, end_pgoff); + + ret = generic_file_fsync(file, start, end, datasync); + +persist: + PERSISTENT_BARRIER(); + NOVA_END_TIMING(fsync_t, fsync_time); + + return ret; +} + +/* This callback is called when a file is closed */ +static int nova_flush(struct file *file, fl_owner_t id) +{ + PERSISTENT_BARRIER(); + return 0; +} + +static int nova_open(struct inode *inode, struct file *filp) +{ + return generic_file_open(inode, filp); +} + const struct file_operations nova_dax_file_operations = { .llseek = nova_llseek, + .open = nova_open, + .fsync = nova_fsync, + .flush = nova_flush, }; const struct inode_operations nova_file_inode_operations = { -- 2.7.4 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm