On Tue, Oct 31, 2017 at 06:56:12PM +0000, fdmanana@xxxxxxxxxx wrote:
> From: Filipe Manana <fdmanana@xxxxxxxx>
>
> The patch from commit 7e3b975a0f92 ("Btrfs: fix reported number of inode
The commit id should be a7e3b975a0f9, looks like a typo, missing 'a' at
the beginning.
> blocks") introduced a regression where if we do a buffered write starting
> at position equal to or greater than the file's size and then stat(2) the
> file before writeback is triggered, the number of used blocks does not
> change (unless there's a prealloc/unwritten extent). Example:
>
> $ xfs_io -f -c "pwrite -S 0xab 0 64K" foobar
> $ du -h foobar
> 0 foobar
> $ sync
> $ du -h foobar
> 64K foobar
>
> The first version of that patch didn't had this regression and the second
> version, which was the one committed, was made only to address some
> performance regression detected by the intel test robots using fs_mark.
>
> This fixes the regression by setting the new delaloc bit in the range, and
> doing it at btrfs_dirty_pages() while setting the regular dealloc bit as
> well, so that this way we set both bits at once avoiding navigation of the
> inode's io tree twice. Doing it at btrfs_dirty_pages() is also the most
> meaninful place, as we should set the new dellaloc bit when if we set the
> delalloc bit, which happens only if we copied bytes into the pages at
> __btrfs_buffered_write().
>
> This was making some of LTP's du tests fail, which can be quickly run
> using a command line like the following:
>
> $ ./runltp -q -p -l /ltp.log -f commands -s du -d /mnt
>
> Fixes: 7e3b975a0f92 ("Btrfs: fix reported number of inode blocks")
> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
> ---
> fs/btrfs/ctree.h | 1 +
> fs/btrfs/extent_io.h | 5 +-
> fs/btrfs/file.c | 123 +++++++++++++++++++++------------------
> fs/btrfs/inode.c | 9 +--
> fs/btrfs/relocation.c | 3 +-
> fs/btrfs/tests/extent-io-tests.c | 6 +-
> fs/btrfs/tests/inode-tests.c | 12 ++--
> 7 files changed, 86 insertions(+), 73 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 8fc690384c58..51f1f3e31608 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -3174,6 +3174,7 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput);
> int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
> int nr);
> int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
> + unsigned int extra_bits,
> struct extent_state **cached_state, int dedupe);
> int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
> struct btrfs_root *new_root,
> diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
> index faffa28ba707..580a6c1c296c 100644
> --- a/fs/btrfs/extent_io.h
> +++ b/fs/btrfs/extent_io.h
> @@ -365,10 +365,11 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
> struct extent_state **cached_state);
>
> static inline int set_extent_delalloc(struct extent_io_tree *tree, u64 start,
> - u64 end, struct extent_state **cached_state)
> + u64 end, unsigned int extra_bits,
> + struct extent_state **cached_state)
> {
> return set_extent_bit(tree, start, end,
> - EXTENT_DELALLOC | EXTENT_UPTODATE,
> + EXTENT_DELALLOC | EXTENT_UPTODATE | extra_bits,
> NULL, cached_state, GFP_NOFS);
> }
>
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index aaab1838cece..bcac827d65f0 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -477,6 +477,47 @@ static void btrfs_drop_pages(struct page **pages, size_t num_pages)
> }
> }
>
> +static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
> + const u64 start,
> + const u64 len,
> + struct extent_state **cached_state)
> +{
...
> +}
Can you please separate moving of btrfs_find_new_delalloc_bytes to
another patch?
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