Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 382 insertions, 0 deletions

diff --git a/fs/quota.c b/fs/quota.c
new file mode 100644
index 000000000000..3f0333a51a23
--- /dev/null
+++ b/fs/quota.c
@@ -0,0 +1,382 @@
+/*
+ * 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/kernel.h>
+#include <linux/smp_lock.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/buffer_head.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_QUOTAOFF:
+                case Q_SETINFO:
+                case Q_SETQUOTA:
+                case Q_GETQUOTA:
+                        /* This is just informative test so we are satisfied without a lock */
+                        if (!sb_has_quota_enabled(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;
+                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) {
+                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 struct super_block *get_super_to_sync(int type)
+{
+        struct list_head *head;
+        int cnt, dirty;
+
+restart:
+        spin_lock(&sb_lock);
+        list_for_each(head, &super_blocks) {
+                struct super_block *sb = list_entry(head, struct super_block, s_list);
+
+                /* This test just improves performance so it needn't be reliable... */
+                for (cnt = 0, dirty = 0; cnt < MAXQUOTAS; cnt++)
+                        if ((type == cnt || type == -1) && sb_has_quota_enabled(sb, cnt)
+                            && info_any_dirty(&sb_dqopt(sb)->info[cnt]))
+                                dirty = 1;
+                if (!dirty)
+                        continue;
+                sb->s_count++;
+                spin_unlock(&sb_lock);
+                down_read(&sb->s_umount);
+                if (!sb->s_root) {
+                        drop_super(sb);
+                        goto restart;
+                }
+                return sb;
+        }
+        spin_unlock(&sb_lock);
+        return NULL;
+}
+
+static void quota_sync_sb(struct super_block *sb, int type)
+{
+        int cnt;
+        struct inode *discard[MAXQUOTAS];
+
+        sb->s_qcop->quota_sync(sb, type);
+        /* 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. We need i_sem and so we could
+         * not do it inside dqonoff_sem. Moreover we need to be carefull
+         * about races with quotaoff() (that is the reason why we have own
+         * reference to inode). */
+        down(&sb_dqopt(sb)->dqonoff_sem);
+        for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+                discard[cnt] = NULL;
+                if (type != -1 && cnt != type)
+                        continue;
+                if (!sb_has_quota_enabled(sb, cnt))
+                        continue;
+                discard[cnt] = igrab(sb_dqopt(sb)->files[cnt]);
+        }
+        up(&sb_dqopt(sb)->dqonoff_sem);
+        for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+                if (discard[cnt]) {
+                        down(&discard[cnt]->i_sem);
+                        truncate_inode_pages(&discard[cnt]->i_data, 0);
+                        up(&discard[cnt]->i_sem);
+                        iput(discard[cnt]);
+                }
+        }
+}
+
+void sync_dquots(struct super_block *sb, int type)
+{
+        if (sb) {
+                if (sb->s_qcop->quota_sync)
+                        quota_sync_sb(sb, type);
+        }
+        else {
+                while ((sb = get_super_to_sync(type)) != NULL) {
+                        if (sb->s_qcop->quota_sync)
+                                quota_sync_sb(sb, type);
+                        drop_super(sb);
+                }
+        }
+}
+
+/* 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;
+
+                        if (IS_ERR(pathname = getname(addr)))
+                                return PTR_ERR(pathname);
+                        ret = sb->s_qcop->quota_on(sb, type, id, pathname);
+                        putname(pathname);
+                        return ret;
+                }
+                case Q_QUOTAOFF:
+                        return sb->s_qcop->quota_off(sb, type);
+
+                case Q_GETFMT: {
+                        __u32 fmt;
+
+                        down_read(&sb_dqopt(sb)->dqptr_sem);
+                        if (!sb_has_quota_enabled(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;
+
+                        if ((ret = sb->s_qcop->get_info(sb, type, &info)))
+                                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;
+
+                        if ((ret = sb->s_qcop->get_dqblk(sb, type, id, &idq)))
+                                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;
+
+                        if ((ret = sb->s_qcop->get_xquota(sb, type, id, &fdq)))
+                                return ret;
+                        if (copy_to_user(addr, &fdq, sizeof(fdq)))
+                                return -EFAULT;
+                        return 0;
+                }
+                /* We never reach here unless validity check is broken */
+                default:
+                        BUG();
+        }
+        return 0;
+}
+
+/*
+ * 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.
+ */
+asmlinkage long sys_quotactl(unsigned int cmd, const char __user *special, qid_t id, void __user *addr)
+{
+        uint cmds, type;
+        struct super_block *sb = NULL;
+        struct block_device *bdev;
+        char *tmp;
+        int ret;
+
+        cmds = cmd >> SUBCMDSHIFT;
+        type = cmd & SUBCMDMASK;
+
+        if (cmds != Q_SYNC || special) {
+                tmp = getname(special);
+                if (IS_ERR(tmp))
+                        return PTR_ERR(tmp);
+                bdev = lookup_bdev(tmp);
+                putname(tmp);
+                if (IS_ERR(bdev))
+                        return PTR_ERR(bdev);
+                sb = get_super(bdev);
+                bdput(bdev);
+                if (!sb)
+                        return -ENODEV;
+        }
+
+        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;
+}