quota: Make VFS quotas use new interface for getting quota info

Create new internal interface for getting information about quota which
contains everything needed for both VFS quotas and XFS quotas. Make VFS
use this and hook it up to Q_GETINFO.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/ext3/super.c

@@ -789,7 +789,7 @@ static const struct quotactl_ops ext3_qctl_operations = {
 	.quota_on	= ext3_quota_on,
 	.quota_off	= dquot_quota_off,
 	.quota_sync	= dquot_quota_sync,
-	.get_info	= dquot_get_dqinfo,
+	.get_state	= dquot_get_state,
 	.set_info	= dquot_set_dqinfo,
 	.get_dqblk	= dquot_get_dqblk,
 	.set_dqblk	= dquot_set_dqblk

fs/ext4/super.c

@@ -1076,7 +1076,7 @@ static const struct quotactl_ops ext4_qctl_operations = {
 	.quota_on	= ext4_quota_on,
 	.quota_off	= ext4_quota_off,
 	.quota_sync	= dquot_quota_sync,
-	.get_info	= dquot_get_dqinfo,
+	.get_state	= dquot_get_state,
 	.set_info	= dquot_set_dqinfo,
 	.get_dqblk	= dquot_get_dqblk,
 	.set_dqblk	= dquot_set_dqblk

fs/quota/dquot.c

@@ -2614,26 +2614,39 @@ int dquot_set_dqblk(struct super_block *sb, struct kqid qid,
 EXPORT_SYMBOL(dquot_set_dqblk);
 
 /* Generic routine for getting common part of quota file information */
-int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
+int dquot_get_state(struct super_block *sb, struct qc_state *state)
 {
 	struct mem_dqinfo *mi;
+	struct qc_type_state *tstate;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	int type;
 
 	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
-	if (!sb_has_quota_active(sb, type)) {
-		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
-		return -ESRCH;
+	memset(state, 0, sizeof(*state));
+	for (type = 0; type < MAXQUOTAS; type++) {
+		if (!sb_has_quota_active(sb, type))
+			continue;
+		tstate = state->s_state + type;
+		mi = sb_dqopt(sb)->info + type;
+		tstate->flags = QCI_ACCT_ENABLED;
+		spin_lock(&dq_data_lock);
+		if (mi->dqi_flags & DQF_SYS_FILE)
+			tstate->flags |= QCI_SYSFILE;
+		if (mi->dqi_flags & DQF_ROOT_SQUASH)
+			tstate->flags |= QCI_ROOT_SQUASH;
+		if (sb_has_quota_limits_enabled(sb, type))
+			tstate->flags |= QCI_LIMITS_ENFORCED;
+		tstate->spc_timelimit = mi->dqi_bgrace;
+		tstate->ino_timelimit = mi->dqi_igrace;
+		tstate->ino = dqopt->files[type]->i_ino;
+		tstate->blocks = dqopt->files[type]->i_blocks;
+		tstate->nextents = 1;	/* We don't know... */
+		spin_unlock(&dq_data_lock);
 	}
-	mi = sb_dqopt(sb)->info + type;
-	spin_lock(&dq_data_lock);
-	ii->dqi_bgrace = mi->dqi_bgrace;
-	ii->dqi_igrace = mi->dqi_igrace;
-	ii->dqi_flags = mi->dqi_flags & DQF_GETINFO_MASK;
-	ii->dqi_valid = IIF_ALL;
-	spin_unlock(&dq_data_lock);
 	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 	return 0;
 }
-EXPORT_SYMBOL(dquot_get_dqinfo);
+EXPORT_SYMBOL(dquot_get_state);
 
 /* Generic routine for setting common part of quota file information */
 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
@@ -2677,7 +2690,7 @@ const struct quotactl_ops dquot_quotactl_ops = {
 	.quota_on	= dquot_quota_on,
 	.quota_off	= dquot_quota_off,
 	.quota_sync	= dquot_quota_sync,
-	.get_info	= dquot_get_dqinfo,
+	.get_state	= dquot_get_state,
 	.set_info	= dquot_set_dqinfo,
 	.get_dqblk	= dquot_get_dqblk,
 	.set_dqblk	= dquot_set_dqblk
@@ -2688,7 +2701,7 @@ const struct quotactl_ops dquot_quotactl_sysfile_ops = {
 	.quota_enable	= dquot_quota_enable,
 	.quota_disable	= dquot_quota_disable,
 	.quota_sync	= dquot_quota_sync,
-	.get_info	= dquot_get_dqinfo,
+	.get_state	= dquot_get_state,
 	.set_info	= dquot_set_dqinfo,
 	.get_dqblk	= dquot_get_dqblk,
 	.set_dqblk	= dquot_set_dqblk

fs/quota/quota.c

@@ -118,13 +118,30 @@ static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 
 static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
 {
-	struct if_dqinfo info;
+	struct qc_state state;
+	struct qc_type_state *tstate;
+	struct if_dqinfo uinfo;
 	int ret;
 
-	if (!sb->s_qcop->get_info)
+	/* This checks whether qc_state has enough entries... */
+	BUILD_BUG_ON(MAXQUOTAS > XQM_MAXQUOTAS);
+	if (!sb->s_qcop->get_state)
 		return -ENOSYS;
-	ret = sb->s_qcop->get_info(sb, type, &info);
-	if (!ret && copy_to_user(addr, &info, sizeof(info)))
+	ret = sb->s_qcop->get_state(sb, &state);
+	if (ret)
+		return ret;
+	tstate = state.s_state + type;
+	if (!(tstate->flags & QCI_ACCT_ENABLED))
+		return -ESRCH;
+	memset(&uinfo, 0, sizeof(uinfo));
+	uinfo.dqi_bgrace = tstate->spc_timelimit;
+	uinfo.dqi_igrace = tstate->ino_timelimit;
+	if (tstate->flags & QCI_SYSFILE)
+		uinfo.dqi_flags |= DQF_SYS_FILE;
+	if (tstate->flags & QCI_ROOT_SQUASH)
+		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
+	uinfo.dqi_valid = IIF_ALL;
+	if (!ret && copy_to_user(addr, &uinfo, sizeof(uinfo)))
 		return -EFAULT;
 	return ret;
 }

fs/reiserfs/super.c

@@ -805,7 +805,7 @@ static const struct quotactl_ops reiserfs_qctl_operations = {
 	.quota_on = reiserfs_quota_on,
 	.quota_off = dquot_quota_off,
 	.quota_sync = dquot_quota_sync,
-	.get_info = dquot_get_dqinfo,
+	.get_state = dquot_get_state,
 	.set_info = dquot_set_dqinfo,
 	.get_dqblk = dquot_get_dqblk,
 	.set_dqblk = dquot_set_dqblk,

include/linux/quota.h

@@ -366,17 +366,48 @@ struct qc_dqblk {
 #define	QC_RT_SPACE	(1<<14)
 #define QC_ACCT_MASK (QC_SPACE | QC_INO_COUNT | QC_RT_SPACE)
 
+#define QCI_SYSFILE		(1 << 0)	/* Quota file is hidden from userspace */
+#define QCI_ROOT_SQUASH		(1 << 1)	/* Root squash turned on */
+#define QCI_ACCT_ENABLED	(1 << 2)	/* Quota accounting enabled */
+#define QCI_LIMITS_ENFORCED	(1 << 3)	/* Quota limits enforced */
+
+/* Structures for communicating via ->get_state */
+struct qc_type_state {
+	unsigned int flags;		/* Flags QCI_* */
+	unsigned int spc_timelimit;	/* Time after which space softlimit is
+					 * enforced */
+	unsigned int ino_timelimit;	/* Ditto for inode softlimit */
+	unsigned int rt_spc_timelimit;	/* Ditto for real-time space */
+	unsigned int spc_warnlimit;	/* Limit for number of space warnings */
+	unsigned int ino_warnlimit;	/* Ditto for inodes */
+	unsigned int rt_spc_warnlimit;	/* Ditto for real-time space */
+	unsigned long long ino;		/* Inode number of quota file */
+	blkcnt_t blocks;		/* Number of 512-byte blocks in the file */
+	blkcnt_t nextents;		/* Number of extents in the file */
+};
+
+struct qc_state {
+	unsigned int s_incoredqs;	/* Number of dquots in core */
+	/*
+	 * Per quota type information. The array should really have
+	 * max(MAXQUOTAS, XQM_MAXQUOTAS) entries. BUILD_BUG_ON in
+	 * quota_getinfo() makes sure XQM_MAXQUOTAS is large enough.  Once VFS
+	 * supports project quotas, this can be changed to MAXQUOTAS
+	 */
+	struct qc_type_state s_state[XQM_MAXQUOTAS];
+};
+
 /* Operations handling requests from userspace */
 struct quotactl_ops {
 	int (*quota_on)(struct super_block *, int, int, struct path *);
 	int (*quota_off)(struct super_block *, int);
 	int (*quota_enable)(struct super_block *, unsigned int);
 	int (*quota_disable)(struct super_block *, unsigned int);
 	int (*quota_sync)(struct super_block *, int);
-	int (*get_info)(struct super_block *, int, struct if_dqinfo *);
 	int (*set_info)(struct super_block *, int, struct if_dqinfo *);
 	int (*get_dqblk)(struct super_block *, struct kqid, struct qc_dqblk *);
 	int (*set_dqblk)(struct super_block *, struct kqid, struct qc_dqblk *);
+	int (*get_state)(struct super_block *, struct qc_state *);
 	int (*get_xstate)(struct super_block *, struct fs_quota_stat *);
 	int (*get_xstatev)(struct super_block *, struct fs_quota_statv *);
 	int (*rm_xquota)(struct super_block *, unsigned int);

include/linux/quotaops.h

@@ -95,7 +95,7 @@ int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
 int dquot_quota_off(struct super_block *sb, int type);
 int dquot_writeback_dquots(struct super_block *sb, int type);
 int dquot_quota_sync(struct super_block *sb, int type);
-int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii);
+int dquot_get_state(struct super_block *sb, struct qc_state *state);
 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii);
 int dquot_get_dqblk(struct super_block *sb, struct kqid id,
 		struct qc_dqblk *di);