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authorVasily Tarasov <vtaras@openvz.org>2007-07-15 23:41:12 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-16 09:05:48 -0700
commitb716395e2b8e450e294537de0c91476ded2f0395 (patch)
tree7f8fd39022c1caca71abb30303a453d77cf4d905 /fs/quota.c
parent4b7775870b69129e640ed583c9b362d5cd66159d (diff)
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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 <vtaras@openvz.org> Cc: Andi Kleen <ak@suse.de> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jan Kara <jack@ucw.cz> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/quota.c')
-rw-r--r--fs/quota.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/fs/quota.c b/fs/quota.c
index 9f237d6182c9..e6577ac15a6c 100644
--- a/fs/quota.c
+++ b/fs/quota.c
@@ -10,12 +10,14 @@
#include <linux/slab.h>
#include <asm/current.h>
#include <asm/uaccess.h>
+#include <linux/compat.h>
#include <linux/kernel.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/buffer_head.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
+#include <linux/types.h>
/* 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