init android origin source code

1 files changed, 394 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/fs/quota/quota.c b/ANDROID_3.4.5/fs/quota/quota.c
new file mode 100644
index 00000000..9a391204
--- /dev/null
+++ b/ANDROID_3.4.5/fs/quota/quota.c
@@ -0,0 +1,394 @@
+/*
+ * 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/security.h>
+#include <linux/syscalls.h>
+#include <linux/capability.h>
+#include <linux/quotaops.h>
+#include <linux/types.h>
+#include <linux/writeback.h>
+
+static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
+				     qid_t id)
+{
+	switch (cmd) {
+	/* these commands do not require any special privilegues */
+	case Q_GETFMT:
+	case Q_SYNC:
+	case Q_GETINFO:
+	case Q_XGETQSTAT:
+	case Q_XQUOTASYNC:
+		break;
+	/* allow to query information for dquots we "own" */
+	case Q_GETQUOTA:
+	case Q_XGETQUOTA:
+		if ((type == USRQUOTA && current_euid() == id) ||
+		    (type == GRPQUOTA && in_egroup_p(id)))
+			break;
+		/*FALLTHROUGH*/
+	default:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+	}
+
+	return security_quotactl(cmd, type, id, sb);
+}
+
+static void quota_sync_one(struct super_block *sb, void *arg)
+{
+	if (sb->s_qcop && sb->s_qcop->quota_sync)
+		sb->s_qcop->quota_sync(sb, *(int *)arg, 1);
+}
+
+static int quota_sync_all(int type)
+{
+	int ret;
+
+	if (type >= MAXQUOTAS)
+		return -EINVAL;
+	ret = security_quotactl(Q_SYNC, type, 0, NULL);
+	if (!ret)
+		iterate_supers(quota_sync_one, &type);
+	return ret;
+}
+
+static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
+		         struct path *path)
+{
+	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)
+		return -ENOSYS;
+	if (sb->s_qcop->quota_on_meta)
+		return sb->s_qcop->quota_on_meta(sb, type, id);
+	if (IS_ERR(path))
+		return PTR_ERR(path);
+	return sb->s_qcop->quota_on(sb, type, id, path);
+}
+
+static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
+{
+	__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;
+}
+
+static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
+{
+	struct if_dqinfo info;
+	int ret;
+
+	if (!sb->s_qcop->get_info)
+		return -ENOSYS;
+	ret = sb->s_qcop->get_info(sb, type, &info);
+	if (!ret && copy_to_user(addr, &info, sizeof(info)))
+		return -EFAULT;
+	return ret;
+}
+
+static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
+{
+	struct if_dqinfo info;
+
+	if (copy_from_user(&info, addr, sizeof(info)))
+		return -EFAULT;
+	if (!sb->s_qcop->set_info)
+		return -ENOSYS;
+	return sb->s_qcop->set_info(sb, type, &info);
+}
+
+static void copy_to_if_dqblk(struct if_dqblk *dst, struct fs_disk_quota *src)
+{
+	dst->dqb_bhardlimit = src->d_blk_hardlimit;
+	dst->dqb_bsoftlimit = src->d_blk_softlimit;
+	dst->dqb_curspace = src->d_bcount;
+	dst->dqb_ihardlimit = src->d_ino_hardlimit;
+	dst->dqb_isoftlimit = src->d_ino_softlimit;
+	dst->dqb_curinodes = src->d_icount;
+	dst->dqb_btime = src->d_btimer;
+	dst->dqb_itime = src->d_itimer;
+	dst->dqb_valid = QIF_ALL;
+}
+
+static int quota_getquota(struct super_block *sb, int type, qid_t id,
+			  void __user *addr)
+{
+	struct fs_disk_quota fdq;
+	struct if_dqblk idq;
+	int ret;
+
+	if (!sb->s_qcop->get_dqblk)
+		return -ENOSYS;
+	ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
+	if (ret)
+		return ret;
+	copy_to_if_dqblk(&idq, &fdq);
+	if (copy_to_user(addr, &idq, sizeof(idq)))
+		return -EFAULT;
+	return 0;
+}
+
+static void copy_from_if_dqblk(struct fs_disk_quota *dst, struct if_dqblk *src)
+{
+	dst->d_blk_hardlimit = src->dqb_bhardlimit;
+	dst->d_blk_softlimit  = src->dqb_bsoftlimit;
+	dst->d_bcount = src->dqb_curspace;
+	dst->d_ino_hardlimit = src->dqb_ihardlimit;
+	dst->d_ino_softlimit = src->dqb_isoftlimit;
+	dst->d_icount = src->dqb_curinodes;
+	dst->d_btimer = src->dqb_btime;
+	dst->d_itimer = src->dqb_itime;
+
+	dst->d_fieldmask = 0;
+	if (src->dqb_valid & QIF_BLIMITS)
+		dst->d_fieldmask |= FS_DQ_BSOFT | FS_DQ_BHARD;
+	if (src->dqb_valid & QIF_SPACE)
+		dst->d_fieldmask |= FS_DQ_BCOUNT;
+	if (src->dqb_valid & QIF_ILIMITS)
+		dst->d_fieldmask |= FS_DQ_ISOFT | FS_DQ_IHARD;
+	if (src->dqb_valid & QIF_INODES)
+		dst->d_fieldmask |= FS_DQ_ICOUNT;
+	if (src->dqb_valid & QIF_BTIME)
+		dst->d_fieldmask |= FS_DQ_BTIMER;
+	if (src->dqb_valid & QIF_ITIME)
+		dst->d_fieldmask |= FS_DQ_ITIMER;
+}
+
+static int quota_setquota(struct super_block *sb, int type, qid_t id,
+			  void __user *addr)
+{
+	struct fs_disk_quota fdq;
+	struct if_dqblk idq;
+
+	if (copy_from_user(&idq, addr, sizeof(idq)))
+		return -EFAULT;
+	if (!sb->s_qcop->set_dqblk)
+		return -ENOSYS;
+	copy_from_if_dqblk(&fdq, &idq);
+	return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
+}
+
+static int quota_setxstate(struct super_block *sb, int cmd, void __user *addr)
+{
+	__u32 flags;
+
+	if (copy_from_user(&flags, addr, sizeof(flags)))
+		return -EFAULT;
+	if (!sb->s_qcop->set_xstate)
+		return -ENOSYS;
+	return sb->s_qcop->set_xstate(sb, flags, cmd);
+}
+
+static int quota_getxstate(struct super_block *sb, void __user *addr)
+{
+	struct fs_quota_stat fqs;
+	int ret;
+
+	if (!sb->s_qcop->get_xstate)
+		return -ENOSYS;
+	ret = sb->s_qcop->get_xstate(sb, &fqs);
+	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
+		return -EFAULT;
+	return ret;
+}
+
+static int quota_setxquota(struct super_block *sb, int type, qid_t id,
+			   void __user *addr)
+{
+	struct fs_disk_quota fdq;
+
+	if (copy_from_user(&fdq, addr, sizeof(fdq)))
+		return -EFAULT;
+	if (!sb->s_qcop->set_dqblk)
+		return -ENOSYS;
+	return sb->s_qcop->set_dqblk(sb, type, id, &fdq);
+}
+
+static int quota_getxquota(struct super_block *sb, int type, qid_t id,
+			   void __user *addr)
+{
+	struct fs_disk_quota fdq;
+	int ret;
+
+	if (!sb->s_qcop->get_dqblk)
+		return -ENOSYS;
+	ret = sb->s_qcop->get_dqblk(sb, type, id, &fdq);
+	if (!ret && copy_to_user(addr, &fdq, sizeof(fdq)))
+		return -EFAULT;
+	return ret;
+}
+
+/* Copy parameters and call proper function */
+static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
+		       void __user *addr, struct path *path)
+{
+	int ret;
+
+	if (type >= (XQM_COMMAND(cmd) ? XQM_MAXQUOTAS : MAXQUOTAS))
+		return -EINVAL;
+	if (!sb->s_qcop)
+		return -ENOSYS;
+
+	ret = check_quotactl_permission(sb, type, cmd, id);
+	if (ret < 0)
+		return ret;
+
+	switch (cmd) {
+	case Q_QUOTAON:
+		return quota_quotaon(sb, type, cmd, id, path);
+	case Q_QUOTAOFF:
+		if (!sb->s_qcop->quota_off)
+			return -ENOSYS;
+		return sb->s_qcop->quota_off(sb, type);
+	case Q_GETFMT:
+		return quota_getfmt(sb, type, addr);
+	case Q_GETINFO:
+		return quota_getinfo(sb, type, addr);
+	case Q_SETINFO:
+		return quota_setinfo(sb, type, addr);
+	case Q_GETQUOTA:
+		return quota_getquota(sb, type, id, addr);
+	case Q_SETQUOTA:
+		return quota_setquota(sb, type, id, addr);
+	case Q_SYNC:
+		if (!sb->s_qcop->quota_sync)
+			return -ENOSYS;
+		return sb->s_qcop->quota_sync(sb, type, 1);
+	case Q_XQUOTAON:
+	case Q_XQUOTAOFF:
+	case Q_XQUOTARM:
+		return quota_setxstate(sb, cmd, addr);
+	case Q_XGETQSTAT:
+		return quota_getxstate(sb, addr);
+	case Q_XSETQLIM:
+		return quota_setxquota(sb, type, id, addr);
+	case Q_XGETQUOTA:
+		return quota_getxquota(sb, type, id, addr);
+	case Q_XQUOTASYNC:
+		if (sb->s_flags & MS_RDONLY)
+			return -EROFS;
+		/* XFS quotas are fully coherent now, making this call a noop */
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+/* Return 1 if 'cmd' will block on frozen filesystem */
+static int quotactl_cmd_write(int cmd)
+{
+	switch (cmd) {
+	case Q_GETFMT:
+	case Q_GETINFO:
+	case Q_SYNC:
+	case Q_XGETQSTAT:
+	case Q_XGETQUOTA:
+	case Q_XQUOTASYNC:
+		return 0;
+	}
+	return 1;
+}
+
+/*
+ * 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, int cmd)
+{
+#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);
+	if (quotactl_cmd_write(cmd))
+		sb = get_super_thawed(bdev);
+	else
+		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;
+	struct path path, *pathp = NULL;
+	int ret;
+
+	cmds = cmd >> SUBCMDSHIFT;
+	type = cmd & SUBCMDMASK;
+
+	/*
+	 * As a special case Q_SYNC can be called without a specific device.
+	 * It will iterate all superblocks that have quota enabled and call
+	 * the sync action on each of them.
+	 */
+	if (!special) {
+		if (cmds == Q_SYNC)
+			return quota_sync_all(type);
+		return -ENODEV;
+	}
+
+	/*
+	 * Path for quotaon has to be resolved before grabbing superblock
+	 * because that gets s_umount sem which is also possibly needed by path
+	 * resolution (think about autofs) and thus deadlocks could arise.
+	 */
+	if (cmds == Q_QUOTAON) {
+		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
+		if (ret)
+			pathp = ERR_PTR(ret);
+		else
+			pathp = &path;
+	}
+
+	sb = quotactl_block(special, cmds);
+	if (IS_ERR(sb)) {
+		ret = PTR_ERR(sb);
+		goto out;
+	}
+
+	ret = do_quotactl(sb, type, cmds, id, addr, pathp);
+
+	drop_super(sb);
+out:
+	if (pathp && !IS_ERR(pathp))
+		path_put(pathp);
+	return ret;
+}