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-rw-r--r--fs/quota/quota.c524
1 files changed, 524 insertions, 0 deletions
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
new file mode 100644
index 0000000..b7f5a46
--- /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
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