Re: [PATCH V9 18/19] xfs: Enable bulkstat ioctl to support 64-bit per-inode extent counters

Darrick J. Wong
2022-04-07T01:31:59Z

On Wed, Apr 06, 2022 at 11:49:02AM +0530, Chandan Babu R wrote:
> The following changes are made to enable userspace to obtain 64-bit extent
> counters,
> 1. Carve out a new 64-bit field xfs_bulkstat->bs_extents64 from
> xfs_bulkstat->bs_pad[] to hold 64-bit extent counter.
> 2. Define the new flag XFS_BULK_IREQ_BULKSTAT for userspace to indicate that
> it is capable of receiving 64-bit extent counters.
>
> Reviewed-by: Dave Chinner <dchinner@redhat.com>
> Suggested-by: Darrick J. Wong <djwong@kernel.org>
> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
> ---
> fs/xfs/libxfs/xfs_fs.h | 20 ++++++++++++++++----
> fs/xfs/xfs_ioctl.c | 3 +++
> fs/xfs/xfs_itable.c | 13 ++++++++++++-
> fs/xfs/xfs_itable.h | 2 ++
> 4 files changed, 33 insertions(+), 5 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> index 1f7238db35cc..2a42bfb85c3b 100644
> --- a/fs/xfs/libxfs/xfs_fs.h
> +++ b/fs/xfs/libxfs/xfs_fs.h
> @@ -378,7 +378,7 @@ struct xfs_bulkstat {
> uint32_t bs_extsize_blks; /* extent size hint, blocks */
>
> uint32_t bs_nlink; /* number of links */
> - uint32_t bs_extents; /* number of extents */
> + uint32_t bs_extents; /* 32-bit data fork extent counter */
> uint32_t bs_aextents; /* attribute number of extents */
> uint16_t bs_version; /* structure version */
> uint16_t bs_forkoff; /* inode fork offset in bytes */
> @@ -387,8 +387,9 @@ struct xfs_bulkstat {
> uint16_t bs_checked; /* checked inode metadata */
> uint16_t bs_mode; /* type and mode */
> uint16_t bs_pad2; /* zeroed */
> + uint64_t bs_extents64; /* 64-bit data fork extent counter */
>
> - uint64_t bs_pad[7]; /* zeroed */
> + uint64_t bs_pad[6]; /* zeroed */
> };
>
> #define XFS_BULKSTAT_VERSION_V1 (1)
> @@ -469,8 +470,19 @@ struct xfs_bulk_ireq {
> */
> #define XFS_BULK_IREQ_SPECIAL (1 << 1)
>
> -#define XFS_BULK_IREQ_FLAGS_ALL (XFS_BULK_IREQ_AGNO | \
> - XFS_BULK_IREQ_SPECIAL)
> +/*
> + * Return data fork extent count via xfs_bulkstat->bs_extents64 field and assign
> + * 0 to xfs_bulkstat->bs_extents when the flag is set. Otherwise, use
> + * xfs_bulkstat->bs_extents for returning data fork extent count and set
> + * xfs_bulkstat->bs_extents64 to 0. In the second case, return -EOVERFLOW and
> + * assign 0 to xfs_bulkstat->bs_extents if data fork extent count is larger than
> + * XFS_MAX_EXTCNT_DATA_FORK_OLD.
> + */
> +#define XFS_BULK_IREQ_NREXT64 (1 << 2)
> +
> +#define XFS_BULK_IREQ_FLAGS_ALL (XFS_BULK_IREQ_AGNO | \
> + XFS_BULK_IREQ_SPECIAL | \
> + XFS_BULK_IREQ_NREXT64)
>
> /* Operate on the root directory inode. */
> #define XFS_BULK_IREQ_SPECIAL_ROOT (1)
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index 83481005317a..e9eadc7337ce 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -813,6 +813,9 @@ xfs_bulk_ireq_setup(
> if (XFS_INO_TO_AGNO(mp, breq->startino) >= mp->m_sb.sb_agcount)
> return -ECANCELED;
>
> + if (hdr->flags & XFS_BULK_IREQ_NREXT64)
> + breq->flags |= XFS_IBULK_NREXT64;
> +
> return 0;
> }
>
> diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
> index 71ed4905f206..847f03f75a38 100644
> --- a/fs/xfs/xfs_itable.c
> +++ b/fs/xfs/xfs_itable.c
> @@ -64,6 +64,7 @@ xfs_bulkstat_one_int(
> struct xfs_inode *ip; /* incore inode pointer */
> struct inode *inode;
> struct xfs_bulkstat *buf = bc->buf;
> + xfs_extnum_t nextents;
> int error = -EINVAL;
>
> if (xfs_internal_inum(mp, ino))
> @@ -102,7 +103,17 @@ xfs_bulkstat_one_int(
>
> buf->bs_xflags = xfs_ip2xflags(ip);
> buf->bs_extsize_blks = ip->i_extsize;
> - buf->bs_extents = xfs_ifork_nextents(&ip->i_df);
> +
> + nextents = xfs_ifork_nextents(&ip->i_df);
> + if (!(bc->breq->flags & XFS_IBULK_NREXT64)) {
> + if (nextents > XFS_MAX_EXTCNT_DATA_FORK_SMALL)
> + buf->bs_extents = XFS_MAX_EXTCNT_DATA_FORK_SMALL;
> + else
> + buf->bs_extents = nextents;

buf->bs_extents = min(nextents, XFS_MAX_EXTCNT_DATA_FORK_SMALL); ?

> + } else {
> + buf->bs_extents64 = nextents;
> + }
> +
> xfs_bulkstat_health(ip, buf);
> buf->bs_aextents = xfs_ifork_nextents(ip->i_afp);
> buf->bs_forkoff = XFS_IFORK_BOFF(ip);
> diff --git a/fs/xfs/xfs_itable.h b/fs/xfs/xfs_itable.h
> index 2cf3872fcd2f..0150fd53d18e 100644
> --- a/fs/xfs/xfs_itable.h
> +++ b/fs/xfs/xfs_itable.h
> @@ -19,6 +19,8 @@ struct xfs_ibulk {
> /* Only iterate within the same AG as startino */
> #define XFS_IBULK_SAME_AG (1 << 0)
>
> +#define XFS_IBULK_NREXT64 (1 << 1)

Needs a comment here.

/* Fill out the bs_extents64 field if set. */
#define XFS_IBULK_NREXT64 (1U << 1)

(Are we supposed to do "1U" now?)

--D

> +
> /*
> * Advance the user buffer pointer by one record of the given size. If the
> * buffer is now full, return the appropriate error code.
> --
> 2.30.2
>