diff options
author | Len Brown <len.brown@intel.com> | 2009-04-05 02:14:15 -0400 |
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committer | Len Brown <len.brown@intel.com> | 2009-04-05 02:14:15 -0400 |
commit | 478c6a43fcbc6c11609f8cee7c7b57223907754f (patch) | |
tree | a7f7952099da60d33032aed6de9c0c56c9f8779e /fs/quota/quota.c | |
parent | 8a3f257c704e02aee9869decd069a806b45be3f1 (diff) | |
parent | 6bb597507f9839b13498781e481f5458aea33620 (diff) |
Merge branch 'linus' into release
Conflicts:
arch/x86/kernel/cpu/cpufreq/longhaul.c
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'fs/quota/quota.c')
-rw-r--r-- | fs/quota/quota.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/fs/quota/quota.c b/fs/quota/quota.c new file mode 100644 index 00000000000..b7f5a468f07 --- /dev/null +++ b/fs/quota/quota.c @@ -0,0 +1,524 @@ +/* + * Quota code necessary even when VFS quota support is not compiled + * into the kernel. The interesting stuff is over in dquot.c, here + * we have symbols for initial quotactl(2) handling, the sysctl(2) + * variables, etc - things needed even when quota support disabled. + */ + +#include <linux/fs.h> +#include <linux/namei.h> +#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) +{ + if (type >= MAXQUOTAS) + return -EINVAL; + if (!sb && cmd != Q_SYNC) + return -ENODEV; + /* Is operation supported? */ + if (sb && !sb->s_qcop) + return -ENOSYS; + + switch (cmd) { + case Q_GETFMT: + break; + case Q_QUOTAON: + if (!sb->s_qcop->quota_on) + return -ENOSYS; + break; + case Q_QUOTAOFF: + if (!sb->s_qcop->quota_off) + return -ENOSYS; + break; + case Q_SETINFO: + if (!sb->s_qcop->set_info) + return -ENOSYS; + break; + case Q_GETINFO: + if (!sb->s_qcop->get_info) + return -ENOSYS; + break; + case Q_SETQUOTA: + if (!sb->s_qcop->set_dqblk) + return -ENOSYS; + break; + case Q_GETQUOTA: + if (!sb->s_qcop->get_dqblk) + return -ENOSYS; + break; + case Q_SYNC: + if (sb && !sb->s_qcop->quota_sync) + return -ENOSYS; + break; + default: + return -EINVAL; + } + + /* Is quota turned on for commands which need it? */ + switch (cmd) { + case Q_GETFMT: + case Q_GETINFO: + case Q_SETINFO: + case Q_SETQUOTA: + case Q_GETQUOTA: + /* This is just an informative test so we are satisfied + * without the lock */ + if (!sb_has_quota_active(sb, type)) + return -ESRCH; + } + + /* Check privileges */ + if (cmd == Q_GETQUOTA) { + if (((type == USRQUOTA && current_euid() != id) || + (type == GRPQUOTA && !in_egroup_p(id))) && + !capable(CAP_SYS_ADMIN)) + return -EPERM; + } + else if (cmd != Q_GETFMT && cmd != Q_SYNC && cmd != Q_GETINFO) + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + return 0; +} + +/* Check validity of XFS Quota Manager commands */ +static int xqm_quotactl_valid(struct super_block *sb, int type, int cmd, + qid_t id) +{ + if (type >= XQM_MAXQUOTAS) + return -EINVAL; + if (!sb) + return -ENODEV; + if (!sb->s_qcop) + return -ENOSYS; + + switch (cmd) { + case Q_XQUOTAON: + case Q_XQUOTAOFF: + case Q_XQUOTARM: + if (!sb->s_qcop->set_xstate) + return -ENOSYS; + break; + case Q_XGETQSTAT: + if (!sb->s_qcop->get_xstate) + return -ENOSYS; + break; + case Q_XSETQLIM: + if (!sb->s_qcop->set_xquota) + return -ENOSYS; + break; + case Q_XGETQUOTA: + if (!sb->s_qcop->get_xquota) + return -ENOSYS; + break; + case Q_XQUOTASYNC: + if (!sb->s_qcop->quota_sync) + return -ENOSYS; + break; + default: + return -EINVAL; + } + + /* Check privileges */ + if (cmd == Q_XGETQUOTA) { + if (((type == XQM_USRQUOTA && current_euid() != id) || + (type == XQM_GRPQUOTA && !in_egroup_p(id))) && + !capable(CAP_SYS_ADMIN)) + return -EPERM; + } else if (cmd != Q_XGETQSTAT && cmd != Q_XQUOTASYNC) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + } + + return 0; +} + +static int check_quotactl_valid(struct super_block *sb, int type, int cmd, + qid_t id) +{ + int error; + + if (XQM_COMMAND(cmd)) + error = xqm_quotactl_valid(sb, type, cmd, id); + else + error = generic_quotactl_valid(sb, type, cmd, id); + if (!error) + error = security_quotactl(cmd, type, id, sb); + return error; +} + +static void quota_sync_sb(struct super_block *sb, int type) +{ + int cnt; + + sb->s_qcop->quota_sync(sb, type); + + if (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE) + return; + /* This is not very clever (and fast) but currently I don't know about + * any other simple way of getting quota data to disk and we must get + * them there for userspace to be visible... */ + if (sb->s_op->sync_fs) + sb->s_op->sync_fs(sb, 1); + sync_blockdev(sb->s_bdev); + + /* + * Now when everything is written we can discard the pagecache so + * that userspace sees the changes. + */ + mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (type != -1 && cnt != type) + continue; + if (!sb_has_quota_active(sb, cnt)) + continue; + mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, + I_MUTEX_QUOTA); + truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); + mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); + } + mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); +} + +void sync_dquots(struct super_block *sb, int type) +{ + int cnt; + + if (sb) { + if (sb->s_qcop->quota_sync) + quota_sync_sb(sb, type); + return; + } + + spin_lock(&sb_lock); +restart: + list_for_each_entry(sb, &super_blocks, s_list) { + /* This test just improves performance so it needn't be + * reliable... */ + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { + if (type != -1 && type != cnt) + continue; + if (!sb_has_quota_active(sb, cnt)) + continue; + if (!info_dirty(&sb_dqopt(sb)->info[cnt]) && + list_empty(&sb_dqopt(sb)->info[cnt].dqi_dirty_list)) + continue; + break; + } + if (cnt == MAXQUOTAS) + continue; + sb->s_count++; + spin_unlock(&sb_lock); + down_read(&sb->s_umount); + if (sb->s_root && sb->s_qcop->quota_sync) + quota_sync_sb(sb, type); + up_read(&sb->s_umount); + spin_lock(&sb_lock); + if (__put_super_and_need_restart(sb)) + goto restart; + } + spin_unlock(&sb_lock); +} + +/* Copy parameters and call proper function */ +static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, + void __user *addr) +{ + int ret; + + switch (cmd) { + case Q_QUOTAON: { + char *pathname; + + pathname = getname(addr); + if (IS_ERR(pathname)) + return PTR_ERR(pathname); + ret = sb->s_qcop->quota_on(sb, type, id, pathname, 0); + putname(pathname); + return ret; + } + case Q_QUOTAOFF: + return sb->s_qcop->quota_off(sb, type, 0); + + case Q_GETFMT: { + __u32 fmt; + + down_read(&sb_dqopt(sb)->dqptr_sem); + if (!sb_has_quota_active(sb, type)) { + up_read(&sb_dqopt(sb)->dqptr_sem); + return -ESRCH; + } + fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id; + up_read(&sb_dqopt(sb)->dqptr_sem); + if (copy_to_user(addr, &fmt, sizeof(fmt))) + return -EFAULT; + return 0; + } + case Q_GETINFO: { + struct if_dqinfo info; + + ret = sb->s_qcop->get_info(sb, type, &info); + if (ret) + return ret; + if (copy_to_user(addr, &info, sizeof(info))) + return -EFAULT; + return 0; + } + case Q_SETINFO: { + struct if_dqinfo info; + + if (copy_from_user(&info, addr, sizeof(info))) + return -EFAULT; + return sb->s_qcop->set_info(sb, type, &info); + } + case Q_GETQUOTA: { + struct if_dqblk idq; + + ret = sb->s_qcop->get_dqblk(sb, type, id, &idq); + if (ret) + return ret; + if (copy_to_user(addr, &idq, sizeof(idq))) + return -EFAULT; + return 0; + } + case Q_SETQUOTA: { + struct if_dqblk idq; + + if (copy_from_user(&idq, addr, sizeof(idq))) + return -EFAULT; + return sb->s_qcop->set_dqblk(sb, type, id, &idq); + } + case Q_SYNC: + sync_dquots(sb, type); + return 0; + + case Q_XQUOTAON: + case Q_XQUOTAOFF: + case Q_XQUOTARM: { + __u32 flags; + + if (copy_from_user(&flags, addr, sizeof(flags))) + return -EFAULT; + return sb->s_qcop->set_xstate(sb, flags, cmd); + } + case Q_XGETQSTAT: { + struct fs_quota_stat fqs; + + if ((ret = sb->s_qcop->get_xstate(sb, &fqs))) + return ret; + if (copy_to_user(addr, &fqs, sizeof(fqs))) + return -EFAULT; + return 0; + } + case Q_XSETQLIM: { + struct fs_disk_quota fdq; + + if (copy_from_user(&fdq, addr, sizeof(fdq))) + return -EFAULT; + return sb->s_qcop->set_xquota(sb, type, id, &fdq); + } + case Q_XGETQUOTA: { + struct fs_disk_quota fdq; + + ret = sb->s_qcop->get_xquota(sb, type, id, &fdq); + if (ret) + return ret; + if (copy_to_user(addr, &fdq, sizeof(fdq))) + return -EFAULT; + return 0; + } + case Q_XQUOTASYNC: + return sb->s_qcop->quota_sync(sb, type); + /* We never reach here unless validity check is broken */ + default: + BUG(); + } + return 0; +} + +/* + * look up a superblock on which quota ops will be performed + * - use the name of a block device to find the superblock thereon + */ +static struct super_block *quotactl_block(const char __user *special) +{ +#ifdef CONFIG_BLOCK + struct block_device *bdev; + struct super_block *sb; + char *tmp = getname(special); + + if (IS_ERR(tmp)) + return ERR_CAST(tmp); + bdev = lookup_bdev(tmp); + putname(tmp); + if (IS_ERR(bdev)) + return ERR_CAST(bdev); + sb = get_super(bdev); + bdput(bdev); + if (!sb) + return ERR_PTR(-ENODEV); + + return sb; +#else + return ERR_PTR(-ENODEV); +#endif +} + +/* + * This is the system call interface. This communicates with + * the user-level programs. Currently this only supports diskquota + * calls. Maybe we need to add the process quotas etc. in the future, + * but we probably should use rlimits for that. + */ +SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, + qid_t, id, void __user *, addr) +{ + uint cmds, type; + struct super_block *sb = NULL; + int ret; + + cmds = cmd >> SUBCMDSHIFT; + type = cmd & SUBCMDMASK; + + if (cmds != Q_SYNC || special) { + sb = quotactl_block(special); + if (IS_ERR(sb)) + return PTR_ERR(sb); + } + + ret = check_quotactl_valid(sb, type, cmds, id); + if (ret >= 0) + ret = do_quotactl(sb, type, cmds, id, addr); + if (sb) + drop_super(sb); + + return ret; +} + +#if defined(CONFIG_COMPAT_FOR_U64_ALIGNMENT) +/* + * 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 |