1 files changed, 437 insertions, 0 deletions

diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c
new file mode 100644
index 000000000..ae99e7b88
--- /dev/null
+++ b/fs/quota/quota_v2.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	vfsv0 quota IO operations on file
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/dqblk_v2.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/quotaops.h>
+
+#include <asm/byteorder.h>
+
+#include "quota_tree.h"
+#include "quotaio_v2.h"
+
+MODULE_AUTHOR("Jan Kara");
+MODULE_DESCRIPTION("Quota format v2 support");
+MODULE_LICENSE("GPL");
+
+static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
+static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
+static int v2r0_is_id(void *dp, struct dquot *dquot);
+static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
+static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
+static int v2r1_is_id(void *dp, struct dquot *dquot);
+
+static const struct qtree_fmt_operations v2r0_qtree_ops = {
+	.mem2disk_dqblk = v2r0_mem2diskdqb,
+	.disk2mem_dqblk = v2r0_disk2memdqb,
+	.is_id = v2r0_is_id,
+};
+
+static const struct qtree_fmt_operations v2r1_qtree_ops = {
+	.mem2disk_dqblk = v2r1_mem2diskdqb,
+	.disk2mem_dqblk = v2r1_disk2memdqb,
+	.is_id = v2r1_is_id,
+};
+
+#define QUOTABLOCK_BITS 10
+#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
+
+static inline qsize_t v2_stoqb(qsize_t space)
+{
+	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
+}
+
+static inline qsize_t v2_qbtos(qsize_t blocks)
+{
+	return blocks << QUOTABLOCK_BITS;
+}
+
+static int v2_read_header(struct super_block *sb, int type,
+			  struct v2_disk_dqheader *dqhead)
+{
+	ssize_t size;
+
+	size = sb->s_op->quota_read(sb, type, (char *)dqhead,
+				    sizeof(struct v2_disk_dqheader), 0);
+	if (size != sizeof(struct v2_disk_dqheader)) {
+		quota_error(sb, "Failed header read: expected=%zd got=%zd",
+			    sizeof(struct v2_disk_dqheader), size);
+		if (size < 0)
+			return size;
+		return -EIO;
+	}
+	return 0;
+}
+
+/* Check whether given file is really vfsv0 quotafile */
+static int v2_check_quota_file(struct super_block *sb, int type)
+{
+	struct v2_disk_dqheader dqhead;
+	static const uint quota_magics[] = V2_INITQMAGICS;
+	static const uint quota_versions[] = V2_INITQVERSIONS;
+
+	if (v2_read_header(sb, type, &dqhead))
+		return 0;
+	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
+	    le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
+		return 0;
+	return 1;
+}
+
+/* Read information header from quota file */
+static int v2_read_file_info(struct super_block *sb, int type)
+{
+	struct v2_disk_dqinfo dinfo;
+	struct v2_disk_dqheader dqhead;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	struct mem_dqinfo *info = &dqopt->info[type];
+	struct qtree_mem_dqinfo *qinfo;
+	ssize_t size;
+	unsigned int version;
+	int ret;
+
+	down_read(&dqopt->dqio_sem);
+	ret = v2_read_header(sb, type, &dqhead);
+	if (ret < 0)
+		goto out;
+	version = le32_to_cpu(dqhead.dqh_version);
+	if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
+	    (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
+	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
+	if (size != sizeof(struct v2_disk_dqinfo)) {
+		quota_error(sb, "Can't read info structure");
+		if (size < 0)
+			ret = size;
+		else
+			ret = -EIO;
+		goto out;
+	}
+	info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
+	if (!info->dqi_priv) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	qinfo = info->dqi_priv;
+	if (version == 0) {
+		/* limits are stored as unsigned 32-bit data */
+		info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
+		info->dqi_max_ino_limit = 0xffffffff;
+	} else {
+		/*
+		 * Used space is stored as unsigned 64-bit value in bytes but
+		 * quota core supports only signed 64-bit values so use that
+		 * as a limit
+		 */
+		info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
+		info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
+	}
+	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
+	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
+	/* No flags currently supported */
+	info->dqi_flags = 0;
+	qinfo->dqi_sb = sb;
+	qinfo->dqi_type = type;
+	qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
+	qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
+	qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
+	qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
+	qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
+	qinfo->dqi_qtree_depth = qtree_depth(qinfo);
+	if (version == 0) {
+		qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
+		qinfo->dqi_ops = &v2r0_qtree_ops;
+	} else {
+		qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
+		qinfo->dqi_ops = &v2r1_qtree_ops;
+	}
+	ret = -EUCLEAN;
+	/* Some sanity checks of the read headers... */
+	if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
+	    i_size_read(sb_dqopt(sb)->files[type])) {
+		quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
+		    (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
+		    i_size_read(sb_dqopt(sb)->files[type]));
+		goto out_free;
+	}
+	if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) {
+		quota_error(sb, "Free block number too big (%u >= %u).",
+			    qinfo->dqi_free_blk, qinfo->dqi_blocks);
+		goto out_free;
+	}
+	if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
+		quota_error(sb, "Block with free entry too big (%u >= %u).",
+			    qinfo->dqi_free_entry, qinfo->dqi_blocks);
+		goto out_free;
+	}
+	ret = 0;
+out_free:
+	if (ret) {
+		kfree(info->dqi_priv);
+		info->dqi_priv = NULL;
+	}
+out:
+	up_read(&dqopt->dqio_sem);
+	return ret;
+}
+
+/* Write information header to quota file */
+static int v2_write_file_info(struct super_block *sb, int type)
+{
+	struct v2_disk_dqinfo dinfo;
+	struct quota_info *dqopt = sb_dqopt(sb);
+	struct mem_dqinfo *info = &dqopt->info[type];
+	struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
+	ssize_t size;
+
+	down_write(&dqopt->dqio_sem);
+	spin_lock(&dq_data_lock);
+	info->dqi_flags &= ~DQF_INFO_DIRTY;
+	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
+	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
+	/* No flags currently supported */
+	dinfo.dqi_flags = cpu_to_le32(0);
+	spin_unlock(&dq_data_lock);
+	dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
+	dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
+	dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
+	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
+	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
+	up_write(&dqopt->dqio_sem);
+	if (size != sizeof(struct v2_disk_dqinfo)) {
+		quota_error(sb, "Can't write info structure");
+		return size < 0 ? size : -EIO;
+	}
+	return 0;
+}
+
+static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
+{
+	struct v2r0_disk_dqblk *d = dp, empty;
+	struct mem_dqblk *m = &dquot->dq_dqb;
+
+	m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
+	m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
+	m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
+	m->dqb_itime = le64_to_cpu(d->dqb_itime);
+	m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
+	m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
+	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
+	m->dqb_btime = le64_to_cpu(d->dqb_btime);
+	/* We need to escape back all-zero structure */
+	memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
+	empty.dqb_itime = cpu_to_le64(1);
+	if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
+		m->dqb_itime = 0;
+}
+
+static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
+{
+	struct v2r0_disk_dqblk *d = dp;
+	struct mem_dqblk *m = &dquot->dq_dqb;
+	struct qtree_mem_dqinfo *info =
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
+
+	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
+	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
+	d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
+	d->dqb_itime = cpu_to_le64(m->dqb_itime);
+	d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
+	d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
+	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
+	d->dqb_btime = cpu_to_le64(m->dqb_btime);
+	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
+	if (qtree_entry_unused(info, dp))
+		d->dqb_itime = cpu_to_le64(1);
+}
+
+static int v2r0_is_id(void *dp, struct dquot *dquot)
+{
+	struct v2r0_disk_dqblk *d = dp;
+	struct qtree_mem_dqinfo *info =
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
+
+	if (qtree_entry_unused(info, dp))
+		return 0;
+	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
+				le32_to_cpu(d->dqb_id)),
+		      dquot->dq_id);
+}
+
+static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
+{
+	struct v2r1_disk_dqblk *d = dp, empty;
+	struct mem_dqblk *m = &dquot->dq_dqb;
+
+	m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
+	m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
+	m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
+	m->dqb_itime = le64_to_cpu(d->dqb_itime);
+	m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
+	m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
+	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
+	m->dqb_btime = le64_to_cpu(d->dqb_btime);
+	/* We need to escape back all-zero structure */
+	memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
+	empty.dqb_itime = cpu_to_le64(1);
+	if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
+		m->dqb_itime = 0;
+}
+
+static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
+{
+	struct v2r1_disk_dqblk *d = dp;
+	struct mem_dqblk *m = &dquot->dq_dqb;
+	struct qtree_mem_dqinfo *info =
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
+
+	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
+	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
+	d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
+	d->dqb_itime = cpu_to_le64(m->dqb_itime);
+	d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
+	d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
+	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
+	d->dqb_btime = cpu_to_le64(m->dqb_btime);
+	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
+	d->dqb_pad = 0;
+	if (qtree_entry_unused(info, dp))
+		d->dqb_itime = cpu_to_le64(1);
+}
+
+static int v2r1_is_id(void *dp, struct dquot *dquot)
+{
+	struct v2r1_disk_dqblk *d = dp;
+	struct qtree_mem_dqinfo *info =
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
+
+	if (qtree_entry_unused(info, dp))
+		return 0;
+	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
+				le32_to_cpu(d->dqb_id)),
+		      dquot->dq_id);
+}
+
+static int v2_read_dquot(struct dquot *dquot)
+{
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+	int ret;
+
+	down_read(&dqopt->dqio_sem);
+	ret = qtree_read_dquot(
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
+			dquot);
+	up_read(&dqopt->dqio_sem);
+	return ret;
+}
+
+static int v2_write_dquot(struct dquot *dquot)
+{
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+	int ret;
+	bool alloc = false;
+
+	/*
+	 * If space for dquot is already allocated, we don't need any
+	 * protection as we'll only overwrite the place of dquot. We are
+	 * still protected by concurrent writes of the same dquot by
+	 * dquot->dq_lock.
+	 */
+	if (!dquot->dq_off) {
+		alloc = true;
+		down_write(&dqopt->dqio_sem);
+	} else {
+		down_read(&dqopt->dqio_sem);
+	}
+	ret = qtree_write_dquot(
+			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
+			dquot);
+	if (alloc)
+		up_write(&dqopt->dqio_sem);
+	else
+		up_read(&dqopt->dqio_sem);
+	return ret;
+}
+
+static int v2_release_dquot(struct dquot *dquot)
+{
+	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+	int ret;
+
+	down_write(&dqopt->dqio_sem);
+	ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
+	up_write(&dqopt->dqio_sem);
+
+	return ret;
+}
+
+static int v2_free_file_info(struct super_block *sb, int type)
+{
+	kfree(sb_dqinfo(sb, type)->dqi_priv);
+	return 0;
+}
+
+static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
+{
+	struct quota_info *dqopt = sb_dqopt(sb);
+	int ret;
+
+	down_read(&dqopt->dqio_sem);
+	ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
+	up_read(&dqopt->dqio_sem);
+	return ret;
+}
+
+static const struct quota_format_ops v2_format_ops = {
+	.check_quota_file	= v2_check_quota_file,
+	.read_file_info		= v2_read_file_info,
+	.write_file_info	= v2_write_file_info,
+	.free_file_info		= v2_free_file_info,
+	.read_dqblk		= v2_read_dquot,
+	.commit_dqblk		= v2_write_dquot,
+	.release_dqblk		= v2_release_dquot,
+	.get_next_id		= v2_get_next_id,
+};
+
+static struct quota_format_type v2r0_quota_format = {
+	.qf_fmt_id	= QFMT_VFS_V0,
+	.qf_ops		= &v2_format_ops,
+	.qf_owner	= THIS_MODULE
+};
+
+static struct quota_format_type v2r1_quota_format = {
+	.qf_fmt_id	= QFMT_VFS_V1,
+	.qf_ops		= &v2_format_ops,
+	.qf_owner	= THIS_MODULE
+};
+
+static int __init init_v2_quota_format(void)
+{
+	int ret;
+
+	ret = register_quota_format(&v2r0_quota_format);
+	if (ret)
+		return ret;
+	return register_quota_format(&v2r1_quota_format);
+}
+
+static void __exit exit_v2_quota_format(void)
+{
+	unregister_quota_format(&v2r0_quota_format);
+	unregister_quota_format(&v2r1_quota_format);
+}
+
+module_init(init_v2_quota_format);
+module_exit(exit_v2_quota_format);