Re: [PATCH 1/3] mm: add filemap_fdatawait_range_keep_errors()

Jan Kara
2019-06-20T09:25:56Z

On Wed 19-06-19 11:21:54, Ross Zwisler wrote:
> In the spirit of filemap_fdatawait_range() and
> filemap_fdatawait_keep_errors(), introduce
> filemap_fdatawait_range_keep_errors() which both takes a range upon
> which to wait and does not clear errors from the address space.
>
> Signed-off-by: Ross Zwisler <zwisler@google.com>

The patch looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> include/linux/fs.h | 2 ++
> mm/filemap.c | 22 ++++++++++++++++++++++
> 2 files changed, 24 insertions(+)
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index f7fdfe93e25d3..79fec8a8413f4 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2712,6 +2712,8 @@ extern int filemap_flush(struct address_space *);
> extern int filemap_fdatawait_keep_errors(struct address_space *mapping);
> extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
> loff_t lend);
> +extern int filemap_fdatawait_range_keep_errors(struct address_space *mapping,
> + loff_t start_byte, loff_t end_byte);
>
> static inline int filemap_fdatawait(struct address_space *mapping)
> {
> diff --git a/mm/filemap.c b/mm/filemap.c
> index df2006ba0cfa5..e87252ca0835a 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -553,6 +553,28 @@ int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
> }
> EXPORT_SYMBOL(filemap_fdatawait_range);
>
> +/**
> + * filemap_fdatawait_range_keep_errors - wait for writeback to complete
> + * @mapping: address space structure to wait for
> + * @start_byte: offset in bytes where the range starts
> + * @end_byte: offset in bytes where the range ends (inclusive)
> + *
> + * Walk the list of under-writeback pages of the given address space in the
> + * given range and wait for all of them. Unlike filemap_fdatawait_range(),
> + * this function does not clear error status of the address space.
> + *
> + * Use this function if callers don't handle errors themselves. Expected
> + * call sites are system-wide / filesystem-wide data flushers: e.g. sync(2),
> + * fsfreeze(8)
> + */
> +int filemap_fdatawait_range_keep_errors(struct address_space *mapping,
> + loff_t start_byte, loff_t end_byte)
> +{
> + __filemap_fdatawait_range(mapping, start_byte, end_byte);
> + return filemap_check_and_keep_errors(mapping);
> +}
> +EXPORT_SYMBOL(filemap_fdatawait_range_keep_errors);
> +
> /**
> * file_fdatawait_range - wait for writeback to complete
> * @file: file pointing to address space structure to wait for
> --
> 2.22.0.410.gd8fdbe21b5-goog
>
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR