On Sun, Jun 23, 2013 at 09:48:26PM -0500, Chandra Seetharaman wrote:
> Added appropriate pads and code for backward compatibility.
>
> Copied over the old version as it is different from the newer padded
> version.
>
> New callers of the system call have to set the version of the data
> structure being passed, and kernel will fill as much data as requested.
Is there are test for this? i.e. that the different version
structures return the same information?
>
> Signed-off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx>
> ---
> fs/gfs2/quota.c | 3 --
> fs/quota/quota.c | 49 +++++++++++++++++++++++++++++++++-
> fs/xfs/xfs_qm_syscalls.c | 4 ---
> fs/xfs/xfs_super.c | 5 +--
> include/uapi/linux/dqblk_xfs.h | 57 +++++++++++++++++++++++++++++++++++-----
> 5 files changed, 99 insertions(+), 19 deletions(-)
>
> diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
> index c7c840e..ca0dccd 100644
> --- a/fs/gfs2/quota.c
> +++ b/fs/gfs2/quota.c
> @@ -1443,9 +1443,6 @@ static int gfs2_quota_get_xstate(struct super_block *sb,
> {
> struct gfs2_sbd *sdp = sb->s_fs_info;
>
> - memset(fqs, 0, sizeof(struct fs_quota_stat));
> - fqs->qs_version = FS_QSTAT_VERSION;
> -
> switch (sdp->sd_args.ar_quota) {
> case GFS2_QUOTA_ON:
> fqs->qs_flags |= (FS_QUOTA_UDQ_ENFD | FS_QUOTA_GDQ_ENFD);
> diff --git a/fs/quota/quota.c b/fs/quota/quota.c
> index c7314f1..ae6526e 100644
> --- a/fs/quota/quota.c
> +++ b/fs/quota/quota.c
> @@ -207,12 +207,57 @@ static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
> static int quota_getxstate(struct super_block *sb, void __user *addr)
> {
> struct fs_quota_stat fqs;
> - int ret;
> + struct fs_quota_stat_v1 fqs_v1;
> + int ret, size;
> + void *fqsp;
>
> if (!sb->s_qcop->get_xstate)
> return -ENOSYS;
> +
> + memset(&fqs, 0, sizeof(struct fs_quota_stat));
> + if (copy_from_user(&fqs, addr, 1)) /* just get the version */
> + return -EFAULT;
> +
> + switch (fqs.qs_version) {
> + case FS_QSTAT_VERSION_2:
> + size = FS_QSTAT_V2_SIZE;
> + break;
> + default:
> + fqs.qs_version = FS_QSTAT_VERSION;
> + /* fallthrough */
> + case FS_QSTAT_VERSION:
> + size = FS_QSTAT_V1_SIZE;
> + break;
> + }
> +
> ret = sb->s_qcop->get_xstate(sb, &fqs);
> - if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
> + if (ret)
> + return ret;
> +
> + if (fqs.qs_version == FS_QSTAT_VERSION) {
> + fqs_v1.qs_version = fqs.qs_version;
> + fqs_v1.qs_flags = fqs.qs_flags;
> + fqs_v1.qs_pad = 0;
> +
> + fqs_v1.qs_uquota.qfs_ino = fqs.qs_uquota.qfs_ino;
> + fqs_v1.qs_uquota.qfs_nblks = fqs.qs_uquota.qfs_nblks;
> + fqs_v1.qs_uquota.qfs_nextents = fqs.qs_uquota.qfs_nextents;
> +
> + fqs_v1.qs_gquota.qfs_ino = fqs.qs_gquota.qfs_ino;
> + fqs_v1.qs_gquota.qfs_nblks = fqs.qs_gquota.qfs_nblks;
> + fqs_v1.qs_gquota.qfs_nextents = fqs.qs_gquota.qfs_nextents;
> +
> + fqs_v1.qs_incoredqs = fqs.qs_incoredqs;
> + fqs_v1.qs_btimelimit = fqs.qs_btimelimit;
> + fqs_v1.qs_itimelimit = fqs.qs_itimelimit;
> + fqs_v1.qs_rtbtimelimit = fqs.qs_rtbtimelimit;
> + fqs_v1.qs_bwarnlimit = fqs.qs_bwarnlimit;
> + fqs_v1.qs_iwarnlimit = fqs.qs_iwarnlimit;
> + fqsp = &fqs_v1;
> + } else
> + fqsp = &fqs;
> +
> + if (copy_to_user(addr, fqsp, size))
> return -EFAULT;
> return ret;
> }
> diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
> index d664a2d..1918f48 100644
> --- a/fs/xfs/xfs_qm_syscalls.c
> +++ b/fs/xfs/xfs_qm_syscalls.c
> @@ -420,9 +420,6 @@ xfs_qm_scall_getqstat(
> bool tempgqip = false;
> bool temppqip = false;
>
> - memset(out, 0, sizeof(fs_quota_stat_t));
> -
> - out->qs_version = FS_QSTAT_VERSION;
> if (!xfs_sb_version_hasquota(&mp->m_sb)) {
> out->qs_uquota.qfs_ino = NULLFSINO;
> out->qs_gquota.qfs_ino = NULLFSINO;
> @@ -432,7 +429,6 @@ xfs_qm_scall_getqstat(
> out->qs_flags = (__uint16_t) xfs_qm_export_flags(mp->m_qflags &
> (XFS_ALL_QUOTA_ACCT|
> XFS_ALL_QUOTA_ENFD));
> - out->qs_pad = 0;
> out->qs_uquota.qfs_ino = mp->m_sb.sb_uquotino;
> out->qs_gquota.qfs_ino = mp->m_sb.sb_gquotino;
> if (&out->qs_gquota != &out->qs_pquota)
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 1bcc017..ab90539 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -554,14 +554,13 @@ xfs_showargs(
> else if (mp->m_qflags & XFS_UQUOTA_ACCT)
> seq_puts(m, "," MNTOPT_UQUOTANOENF);
>
> - /* Either project or group quotas can be active, not both */
> -
> if (mp->m_qflags & XFS_PQUOTA_ACCT) {
> if (mp->m_qflags & XFS_PQUOTA_ENFD)
> seq_puts(m, "," MNTOPT_PRJQUOTA);
> else
> seq_puts(m, "," MNTOPT_PQUOTANOENF);
> - } else if (mp->m_qflags & XFS_GQUOTA_ACCT) {
> + }
> + if (mp->m_qflags & XFS_GQUOTA_ACCT) {
> if (mp->m_qflags & XFS_GQUOTA_ENFD)
> seq_puts(m, "," MNTOPT_GRPQUOTA);
> else
> diff --git a/include/uapi/linux/dqblk_xfs.h b/include/uapi/linux/dqblk_xfs.h
> index f17e3bb..e8ca23b 100644
> --- a/include/uapi/linux/dqblk_xfs.h
> +++ b/include/uapi/linux/dqblk_xfs.h
> @@ -47,6 +47,7 @@
> * 512 bytes.
> */
> #define FS_DQUOT_VERSION 1 /* fs_disk_quota.d_version */
> +
> typedef struct fs_disk_quota {
> __s8 d_version; /* version of this structure */
> __s8 d_flags; /* FS_{USER,PROJ,GROUP}_QUOTA */
> @@ -137,31 +138,73 @@ typedef struct fs_disk_quota {
> * Provides a centralized way to get meta information about the quota subsystem.
> * eg. space taken up for user and group quotas, number of dquots currently
> * incore.
> + * User space caller should set qs_version to the appropriate version
> + * of the fs_quota_stat data structure they are providing. Not providing
> + * a version will be treated as FS_QSTAT_VERSION.
> */
> #define FS_QSTAT_VERSION 1 /* fs_quota_stat.qs_version */
> +#define FS_QSTAT_VERSION_2 2 /* new field qs_pquota; realignment */
>
> /*
> * Some basic information about 'quota files'.
> */
> -typedef struct fs_qfilestat {
> +struct fs_qfilestat_v1 {
> __u64 qfs_ino; /* inode number */
> __u64 qfs_nblks; /* number of BBs 512-byte-blks */
> __u32 qfs_nextents; /* number of extents */
> -} fs_qfilestat_t;
> +};
>
> -typedef struct fs_quota_stat {
> +struct fs_quota_stat_v1 {
> __s8 qs_version; /* version number for future changes */
> __u16 qs_flags; /* FS_QUOTA_{U,P,G}DQ_{ACCT,ENFD} */
> __s8 qs_pad; /* unused */
> - fs_qfilestat_t qs_uquota; /* user quota storage information */
> - fs_qfilestat_t qs_gquota; /* group quota storage information */
> -#define qs_pquota qs_gquota
> + struct fs_qfilestat_v1 qs_uquota; /* user quota information */
> + struct fs_qfilestat_v1 qs_gquota; /* group quota information */
> __u32 qs_incoredqs; /* number of dquots incore */
> __s32 qs_btimelimit; /* limit for blks timer */
> __s32 qs_itimelimit; /* limit for inodes timer */
> __s32 qs_rtbtimelimit;/* limit for rt blks timer */
> __u16 qs_bwarnlimit; /* limit for num warnings */
> __u16 qs_iwarnlimit; /* limit for num warnings */
> -} fs_quota_stat_t;
> +};
> +
> +/*
> + * Some basic information about 'quota files'. Version 2.
> + */
> +struct fs_qfilestat {
> + __u64 qfs_ino; /* inode number */
> + __u64 qfs_nblks; /* number of BBs 512-byte-blks */
> + __u32 qfs_nextents; /* number of extents */
> + __u8 qfs_pad[4]; /* pad for 8-byte alignment */
Just pad it as:
__u32 qfs_pad;
So the size of the hole being filled is obvious.
> +};
> +
> +struct fs_quota_stat {
> + __s8 qs_version; /* version for future changes */
> + __u8 qs_pad1; /* pad for 16bit alignment */
> + __u16 qs_flags; /* FS_QUOTA_.* flags */
> + __u8 qs_pad2[4]; /* pad for 8-byte alignment */
Actually, we can reorder this structure so there aren't intermediate
holes like this. The only thing that matters is that the first byte
is the version number. So:
struct fs_quota_stat {
__s8 qs_version; /* version for future changes */
__u8 qs_pad1; /* pad for 16bit alignment */
__u16 qs_flags; /* FS_QUOTA_.* flags */
__u32 qs_incoredqs; /* number of dquots incore */
struct fs_qfilestat qs_uquota; /* user quota information */
struct fs_qfilestat qs_gquota; /* group quota information */
struct fs_qfilestat qs_pquota; /* project quota information */
__s32 qs_btimelimit; /* limit for blks timer */
__s32 qs_itimelimit; /* limit for inodes timer */
__s32 qs_rtbtimelimit;/* limit for rt blks timer */
__u16 qs_bwarnlimit; /* limit for num warnings */
__u16 qs_iwarnlimit; /* limit for num warnings */
__u32 qs_pad2; /* pad for 8-byte alignment */
__u64 qs_pad3[8]; /* for future proofing */
};
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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