From b716395e2b8e450e294537de0c91476ded2f0395 Mon Sep 17 00:00:00 2001 From: Vasily Tarasov Date: Sun, 15 Jul 2007 23:41:12 -0700 Subject: diskquota: 32bit quota tools on 64bit architectures OpenVZ Linux kernel team has discovered the problem with 32bit quota tools working on 64bit architectures. In 2.6.10 kernel sys32_quotactl() function was replaced by sys_quotactl() with the comment "sys_quotactl seems to be 32/64bit clean, enable it for 32bit" However this isn't right. Look at if_dqblk structure: struct if_dqblk { __u64 dqb_bhardlimit; __u64 dqb_bsoftlimit; __u64 dqb_curspace; __u64 dqb_ihardlimit; __u64 dqb_isoftlimit; __u64 dqb_curinodes; __u64 dqb_btime; __u64 dqb_itime; __u32 dqb_valid; }; For 32 bit quota tools sizeof(if_dqblk) == 0x44. But for 64 bit kernel its size is 0x48, 'cause of alignment! Thus we got a problem. Attached patch reintroduce sys32_quotactl() function, that handles this and related situations. [michal.k.k.piotrowski@gmail.com: build fix] [akpm@linux-foundation.org: Make it link with CONFIG_QUOTA=n] Signed-off-by: Vasily Tarasov Cc: Andi Kleen Cc: "Luck, Tony" Cc: Jan Kara Cc: Signed-off-by: Michal Piotrowski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/quota.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) (limited to 'fs/quota.c') diff --git a/fs/quota.c b/fs/quota.c index 9f237d6182c..e6577ac15a6 100644 --- a/fs/quota.c +++ b/fs/quota.c @@ -10,12 +10,14 @@ #include #include #include +#include #include #include #include #include #include #include +#include /* Check validity of generic quotactl commands */ static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id) @@ -384,3 +386,119 @@ asmlinkage long sys_quotactl(unsigned int cmd, const char __user *special, qid_t return ret; } + +#if defined(CONFIG_X86_64) || defined(CONFIG_IA64) +/* + * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64) + * and is necessary due to alignment problems. + */ +struct compat_if_dqblk { + compat_u64 dqb_bhardlimit; + compat_u64 dqb_bsoftlimit; + compat_u64 dqb_curspace; + compat_u64 dqb_ihardlimit; + compat_u64 dqb_isoftlimit; + compat_u64 dqb_curinodes; + compat_u64 dqb_btime; + compat_u64 dqb_itime; + compat_uint_t dqb_valid; +}; + +/* XFS structures */ +struct compat_fs_qfilestat { + compat_u64 dqb_bhardlimit; + compat_u64 qfs_nblks; + compat_uint_t qfs_nextents; +}; + +struct compat_fs_quota_stat { + __s8 qs_version; + __u16 qs_flags; + __s8 qs_pad; + struct compat_fs_qfilestat qs_uquota; + struct compat_fs_qfilestat qs_gquota; + compat_uint_t qs_incoredqs; + compat_int_t qs_btimelimit; + compat_int_t qs_itimelimit; + compat_int_t qs_rtbtimelimit; + __u16 qs_bwarnlimit; + __u16 qs_iwarnlimit; +}; + +asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, + qid_t id, void __user *addr) +{ + unsigned int cmds; + struct if_dqblk __user *dqblk; + struct compat_if_dqblk __user *compat_dqblk; + struct fs_quota_stat __user *fsqstat; + struct compat_fs_quota_stat __user *compat_fsqstat; + compat_uint_t data; + u16 xdata; + long ret; + + cmds = cmd >> SUBCMDSHIFT; + + switch (cmds) { + case Q_GETQUOTA: + dqblk = compat_alloc_user_space(sizeof(struct if_dqblk)); + compat_dqblk = addr; + ret = sys_quotactl(cmd, special, id, dqblk); + if (ret) + break; + if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) || + get_user(data, &dqblk->dqb_valid) || + put_user(data, &compat_dqblk->dqb_valid)) + ret = -EFAULT; + break; + case Q_SETQUOTA: + dqblk = compat_alloc_user_space(sizeof(struct if_dqblk)); + compat_dqblk = addr; + ret = -EFAULT; + if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) || + get_user(data, &compat_dqblk->dqb_valid) || + put_user(data, &dqblk->dqb_valid)) + break; + ret = sys_quotactl(cmd, special, id, dqblk); + break; + case Q_XGETQSTAT: + fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat)); + compat_fsqstat = addr; + ret = sys_quotactl(cmd, special, id, fsqstat); + if (ret) + break; + ret = -EFAULT; + /* Copying qs_version, qs_flags, qs_pad */ + if (copy_in_user(compat_fsqstat, fsqstat, + offsetof(struct compat_fs_quota_stat, qs_uquota))) + break; + /* Copying qs_uquota */ + if (copy_in_user(&compat_fsqstat->qs_uquota, + &fsqstat->qs_uquota, + sizeof(compat_fsqstat->qs_uquota)) || + get_user(data, &fsqstat->qs_uquota.qfs_nextents) || + put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents)) + break; + /* Copying qs_gquota */ + if (copy_in_user(&compat_fsqstat->qs_gquota, + &fsqstat->qs_gquota, + sizeof(compat_fsqstat->qs_gquota)) || + get_user(data, &fsqstat->qs_gquota.qfs_nextents) || + put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents)) + break; + /* Copying the rest */ + if (copy_in_user(&compat_fsqstat->qs_incoredqs, + &fsqstat->qs_incoredqs, + sizeof(struct compat_fs_quota_stat) - + offsetof(struct compat_fs_quota_stat, qs_incoredqs)) || + get_user(xdata, &fsqstat->qs_iwarnlimit) || + put_user(xdata, &compat_fsqstat->qs_iwarnlimit)) + break; + ret = 0; + break; + default: + ret = sys_quotactl(cmd, special, id, addr); + } + return ret; +} +#endif -- cgit v1.2.3