Re: [PATCH 08/10] xfs: look at m_frextents in xfs_iomap_prealloc_size for RT allocations

Darrick J. Wong
2024-02-23T17:21:58Z

On Fri, Feb 23, 2024 at 08:15:04AM +0100, Christoph Hellwig wrote:
> Add a check for files on the RT subvolume and use m_frextents instead
> of m_fdblocks to adjust the preallocation size.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> fs/xfs/xfs_iomap.c | 42 ++++++++++++++++++++++++++++++------------
> 1 file changed, 30 insertions(+), 12 deletions(-)
>
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index 18c8f168b1532d..e6abe56d1f1f23 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -27,6 +27,7 @@
> #include "xfs_dquot_item.h"
> #include "xfs_dquot.h"
> #include "xfs_reflink.h"
> +#include "xfs_rtbitmap.h"
>
> #define XFS_ALLOC_ALIGN(mp, off) \
> (((off) >> mp->m_allocsize_log) << mp->m_allocsize_log)
> @@ -398,6 +399,29 @@ xfs_quota_calc_throttle(
> }
> }
>
> +static int64_t
> +xfs_iomap_freesp(
> + struct percpu_counter *counter,
> + uint64_t low_space[XFS_LOWSP_MAX],
> + int *shift)
> +{
> + int64_t freesp;
> +
> + freesp = percpu_counter_read_positive(counter);
> + if (freesp < low_space[XFS_LOWSP_5_PCNT]) {
> + *shift = 2;
> + if (freesp < low_space[XFS_LOWSP_4_PCNT])
> + (*shift)++;
> + if (freesp < low_space[XFS_LOWSP_3_PCNT])
> + (*shift)++;
> + if (freesp < low_space[XFS_LOWSP_2_PCNT])
> + (*shift)++;
> + if (freesp < low_space[XFS_LOWSP_1_PCNT])
> + (*shift)++;
> + }
> + return freesp;
> +}
> +
> /*
> * If we don't have a user specified preallocation size, dynamically increase
> * the preallocation size as the size of the file grows. Cap the maximum size
> @@ -480,18 +504,12 @@ xfs_iomap_prealloc_size(
> alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(XFS_MAX_BMBT_EXTLEN),
> alloc_blocks);
>
> - freesp = percpu_counter_read_positive(&mp->m_fdblocks);
> - if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) {
> - shift = 2;
> - if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT])
> - shift++;
> - if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT])
> - shift++;
> - if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT])
> - shift++;
> - if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT])
> - shift++;
> - }
> + if (unlikely(XFS_IS_REALTIME_INODE(ip)))
> + freesp = xfs_rtx_to_rtb(mp, xfs_iomap_freesp(&mp->m_frextents,
> + mp->m_low_rtexts, &shift));
> + else
> + freesp = xfs_iomap_freesp(&mp->m_fdblocks, mp->m_low_space,
> + &shift);
>
> /*
> * Check each quota to cap the prealloc size, provide a shift value to
> --
> 2.39.2
>
>