Re: [PATCH 6/9] xfs: wire up the new v5 bulkstat_single ioctl

Allison Collins
2019-06-05T22:30:41Z

On 5/29/19 3:28 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Wire up the V5 BULKSTAT_SINGLE ioctl and rename the old one V1.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/libxfs/xfs_fs.h | 16 +++++++++
> fs/xfs/xfs_ioctl.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
> fs/xfs/xfs_ioctl32.c | 1 +
> fs/xfs/xfs_ondisk.h | 1 +
> 4 files changed, 103 insertions(+)
>
>
> diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> index 960f3542e207..95d0411dae9b 100644
> --- a/fs/xfs/libxfs/xfs_fs.h
> +++ b/fs/xfs/libxfs/xfs_fs.h
> @@ -468,6 +468,16 @@ struct xfs_bulk_ireq {
>
> #define XFS_BULK_IREQ_FLAGS_ALL (0)
>
> +/* Header for a single inode request. */
> +struct xfs_ireq {
> + uint64_t ino; /* I/O: start with this inode */
> + uint32_t flags; /* I/O: operation flags */
> + uint32_t reserved32; /* must be zero */
> + uint64_t reserved[2]; /* must be zero */
> +};
> +
> +#define XFS_IREQ_FLAGS_ALL (0)
> +
> /*
> * ioctl structures for v5 bulkstat and inumbers requests
> */
> @@ -478,6 +488,11 @@ struct xfs_bulkstat_req {
> #define XFS_BULKSTAT_REQ_SIZE(nr) (sizeof(struct xfs_bulkstat_req) + \
> (nr) * sizeof(struct xfs_bulkstat))
>
> +struct xfs_bulkstat_single_req {
> + struct xfs_ireq hdr;
> + struct xfs_bulkstat bulkstat;
> +};
> +
> /*
> * Error injection.
> */
> @@ -780,6 +795,7 @@ struct xfs_scrub_metadata {
> #define XFS_IOC_GOINGDOWN _IOR ('X', 125, uint32_t)
> #define XFS_IOC_FSGEOMETRY _IOR ('X', 126, struct xfs_fsop_geom)
> #define XFS_IOC_BULKSTAT _IOR ('X', 127, struct xfs_bulkstat_req)
> +#define XFS_IOC_BULKSTAT_SINGLE _IOR ('X', 128, struct xfs_bulkstat_single_req)
> /* XFS_IOC_GETFSUUID ---------- deprecated 140 */
>
>
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index f6724c75ba97..f6971eb9561e 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -923,6 +923,89 @@ xfs_ioc_bulkstat(
> return 0;
> }
>
> +/*
> + * Check the incoming singleton request @hdr from userspace and initialize the
> + * internal @breq bulk request appropriately. Returns 0 if the bulk request
> + * should proceed; or the usual negative error code.
> + */
> +static int
> +xfs_ireq_setup(
> + struct xfs_mount *mp,
> + struct xfs_ireq *hdr,
> + struct xfs_ibulk *breq,
> + void __user *ubuffer)
> +{
> + if ((hdr->flags & ~XFS_IREQ_FLAGS_ALL) ||
> + hdr->reserved32 ||
> + memchr_inv(hdr->reserved, 0, sizeof(hdr->reserved)))
> + return -EINVAL;
> +
> + if (XFS_INO_TO_AGNO(mp, hdr->ino) >= mp->m_sb.sb_agcount)
> + return -EINVAL;
> +
> + breq->ubuffer = ubuffer;
> + breq->icount = 1;
> + breq->startino = hdr->ino;
> + return 0;
> +}
> +
> +/*
> + * Update the userspace singleton request @hdr to reflect the end state of the
> + * internal bulk request @breq. If @error is negative then we return just
> + * that; otherwise we copy the state so that userspace can discover what
> + * happened.
> + */
> +static int
> +xfs_ireq_teardown(
> + struct xfs_ireq *hdr,
> + struct xfs_ibulk *breq,
> + int error)
> +{
> + if (error < 0)
> + return error;
Similar nit about the error code here too. This function is so small,
it might make sense to just factor it up into the calling function,
sense I don't see it used else where in the set. I suppose it's good to
keep things consistent too though, it seem to be the pattern that the
other ioctls use.

I think the rest is ok though

Allison

> +
> + hdr->ino = breq->startino;
> + return 0;
> +}
> +
> +/* Handle the v5 bulkstat_single ioctl. */
> +STATIC int
> +xfs_ioc_bulkstat_single(
> + struct xfs_mount *mp,
> + unsigned int cmd,
> + struct xfs_bulkstat_single_req __user *arg)
> +{
> + struct xfs_ireq hdr;
> + struct xfs_ibulk breq = {
> + .mp = mp,
> + };
> + int error;
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + if (XFS_FORCED_SHUTDOWN(mp))
> + return -EIO;
> +
> + if (copy_from_user(&hdr, &arg->hdr, sizeof(hdr)))
> + return -EFAULT;
> +
> + error = xfs_ireq_setup(mp, &hdr, &breq, &arg->bulkstat);
> + if (error)
> + return error;
> +
> + error = xfs_bulkstat_one(&breq, xfs_bulkstat_fmt);
> +
> + error = xfs_ireq_teardown(&hdr, &breq, error);
> + if (error)
> + return error;
> +
> + if (copy_to_user(&arg->hdr, &hdr, sizeof(hdr)))
> + return -EFAULT;
> +
> + return 0;
> +}
> +
> STATIC int
> xfs_ioc_fsgeometry(
> struct xfs_mount *mp,
> @@ -2089,6 +2172,8 @@ xfs_file_ioctl(
>
> case XFS_IOC_BULKSTAT:
> return xfs_ioc_bulkstat(mp, cmd, arg);
> + case XFS_IOC_BULKSTAT_SINGLE:
> + return xfs_ioc_bulkstat_single(mp, cmd, arg);
>
> case XFS_IOC_FSGEOMETRY_V1:
> return xfs_ioc_fsgeometry(mp, arg, 3);
> diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
> index 84c342be4536..08a90e3459d1 100644
> --- a/fs/xfs/xfs_ioctl32.c
> +++ b/fs/xfs/xfs_ioctl32.c
> @@ -577,6 +577,7 @@ xfs_file_compat_ioctl(
> case FS_IOC_GETFSMAP:
> case XFS_IOC_SCRUB_METADATA:
> case XFS_IOC_BULKSTAT:
> + case XFS_IOC_BULKSTAT_SINGLE:
> return xfs_file_ioctl(filp, cmd, p);
> #if !defined(BROKEN_X86_ALIGNMENT) || defined(CONFIG_X86_X32)
> /*
> diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
> index 954484c6eb96..fa1252657b08 100644
> --- a/fs/xfs/xfs_ondisk.h
> +++ b/fs/xfs/xfs_ondisk.h
> @@ -150,6 +150,7 @@ xfs_check_ondisk_structs(void)
> XFS_CHECK_STRUCT_SIZE(struct xfs_bulkstat, 192);
> XFS_CHECK_STRUCT_SIZE(struct xfs_inumbers, 24);
> XFS_CHECK_STRUCT_SIZE(struct xfs_bulkstat_req, 64);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_bulkstat_single_req, 224);
> }
>
> #endif /* __XFS_ONDISK_H */
>