fs/ceph/quota.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * quota.c - CephFS quota
  *
  * Copyright (C) 2017-2018 SUSE
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
  * of the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/statfs.h>

 #include "super.h"
 #include "mds_client.h"

 void ceph_adjust_quota_realms_count(struct inode *inode, bool inc)
 {
 	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 	if (inc)
 		atomic64_inc(&mdsc->quotarealms_count);
 	else
 		atomic64_dec(&mdsc->quotarealms_count);
 }

 static inline bool ceph_has_realms_with_quotas(struct inode *inode)
 {
 	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 	return atomic64_read(&mdsc->quotarealms_count) > 0;
 }

 void ceph_handle_quota(struct ceph_mds_client *mdsc,
 		       struct ceph_mds_session *session,
 		       struct ceph_msg *msg)
 {
 	struct super_block *sb = mdsc->fsc->sb;
 	struct ceph_mds_quota *h = msg->front.iov_base;
 	struct ceph_vino vino;
 	struct inode *inode;
 	struct ceph_inode_info *ci;

 	if (msg->front.iov_len < sizeof(*h)) {
 		pr_err("%s corrupt message mds%d len %d\n", __func__,
 		       session->s_mds, (int)msg->front.iov_len);
 		ceph_msg_dump(msg);
 		return;
 	}

 	/* increment msg sequence number */
 	mutex_lock(&session->s_mutex);
 	session->s_seq++;
 	mutex_unlock(&session->s_mutex);

 	/* lookup inode */
 	vino.ino = le64_to_cpu(h->ino);
 	vino.snap = CEPH_NOSNAP;
 	inode = ceph_find_inode(sb, vino);
 	if (!inode) {
 		pr_warn("Failed to find inode %llu\n", vino.ino);
 		return;
 	}
 	ci = ceph_inode(inode);

 	spin_lock(&ci->i_ceph_lock);
 	ci->i_rbytes = le64_to_cpu(h->rbytes);
 	ci->i_rfiles = le64_to_cpu(h->rfiles);
 	ci->i_rsubdirs = le64_to_cpu(h->rsubdirs);
 	__ceph_update_quota(ci, le64_to_cpu(h->max_bytes),
 		            le64_to_cpu(h->max_files));
 	spin_unlock(&ci->i_ceph_lock);

 	iput(inode);
 }

 /*
  * This function walks through the snaprealm for an inode and returns the
  * ceph_snap_realm for the first snaprealm that has quotas set (either max_files
  * or max_bytes).  If the root is reached, return the root ceph_snap_realm
  * instead.
  *
  * Note that the caller is responsible for calling ceph_put_snap_realm() on the
  * returned realm.
  */
 static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc,
 					       struct inode *inode)
 {
 	struct ceph_inode_info *ci = NULL;
 	struct ceph_snap_realm *realm, *next;
 	struct inode *in;
 	bool has_quota;

 	if (ceph_snap(inode) != CEPH_NOSNAP)
 		return NULL;

 	realm = ceph_inode(inode)->i_snap_realm;
 	if (realm)
 		ceph_get_snap_realm(mdsc, realm);
 	else
 		pr_err_ratelimited("get_quota_realm: ino (%llx.%llx) "
 				   "null i_snap_realm\n", ceph_vinop(inode));
 	while (realm) {
 		spin_lock(&realm->inodes_with_caps_lock);
 		in = realm->inode ? igrab(realm->inode) : NULL;
 		spin_unlock(&realm->inodes_with_caps_lock);
 		if (!in)
 			break;

 		ci = ceph_inode(in);
 		has_quota = __ceph_has_any_quota(ci);
 		iput(in);

 		next = realm->parent;
 		if (has_quota || !next)
 		       return realm;

 		ceph_get_snap_realm(mdsc, next);
 		ceph_put_snap_realm(mdsc, realm);
 		realm = next;
 	}
 	if (realm)
 		ceph_put_snap_realm(mdsc, realm);

 	return NULL;
 }

 bool ceph_quota_is_same_realm(struct inode *old, struct inode *new)
 {
 	struct ceph_mds_client *mdsc = ceph_inode_to_client(old)->mdsc;
 	struct ceph_snap_realm *old_realm, *new_realm;
 	bool is_same;

 	down_read(&mdsc->snap_rwsem);
 	old_realm = get_quota_realm(mdsc, old);
 	new_realm = get_quota_realm(mdsc, new);
 	is_same = (old_realm == new_realm);
 	up_read(&mdsc->snap_rwsem);

 	if (old_realm)
 		ceph_put_snap_realm(mdsc, old_realm);
 	if (new_realm)
 		ceph_put_snap_realm(mdsc, new_realm);

 	return is_same;
 }

 enum quota_check_op {
 	QUOTA_CHECK_MAX_FILES_OP,	/* check quota max_files limit */
 	QUOTA_CHECK_MAX_BYTES_OP,	/* check quota max_files limit */
 	QUOTA_CHECK_MAX_BYTES_APPROACHING_OP	/* check if quota max_files
 						   limit is approaching */
 };

 /*
  * check_quota_exceeded() will walk up the snaprealm hierarchy and, for each
  * realm, it will execute quota check operation defined by the 'op' parameter.
  * The snaprealm walk is interrupted if the quota check detects that the quota
  * is exceeded or if the root inode is reached.
  */
 static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op,
 				 loff_t delta)
 {
 	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 	struct ceph_inode_info *ci;
 	struct ceph_snap_realm *realm, *next;
 	struct inode *in;
 	u64 max, rvalue;
 	bool exceeded = false;

 	if (ceph_snap(inode) != CEPH_NOSNAP)
 		return false;

 	down_read(&mdsc->snap_rwsem);
 	realm = ceph_inode(inode)->i_snap_realm;
 	if (realm)
 		ceph_get_snap_realm(mdsc, realm);
 	else
 		pr_err_ratelimited("check_quota_exceeded: ino (%llx.%llx) "
 				   "null i_snap_realm\n", ceph_vinop(inode));
 	while (realm) {
 		spin_lock(&realm->inodes_with_caps_lock);
 		in = realm->inode ? igrab(realm->inode) : NULL;
 		spin_unlock(&realm->inodes_with_caps_lock);
 		if (!in)
 			break;

 		ci = ceph_inode(in);
 		spin_lock(&ci->i_ceph_lock);
 		if (op == QUOTA_CHECK_MAX_FILES_OP) {
 			max = ci->i_max_files;
 			rvalue = ci->i_rfiles + ci->i_rsubdirs;
 		} else {
 			max = ci->i_max_bytes;
 			rvalue = ci->i_rbytes;
 		}
 		spin_unlock(&ci->i_ceph_lock);
 		switch (op) {
 		case QUOTA_CHECK_MAX_FILES_OP:
 			exceeded = (max && (rvalue >= max));
 			break;
 		case QUOTA_CHECK_MAX_BYTES_OP:
 			exceeded = (max && (rvalue + delta > max));
 			break;
 		case QUOTA_CHECK_MAX_BYTES_APPROACHING_OP:
 			if (max) {
 				if (rvalue >= max)
 					exceeded = true;
 				else {
 					/*
 					 * when we're writing more that 1/16th
 					 * of the available space
 					 */
 					exceeded =
 						(((max - rvalue) >> 4) < delta);
 				}
 			}
 			break;
 		default:
 			/* Shouldn't happen */
 			pr_warn("Invalid quota check op (%d)\n", op);
 			exceeded = true; /* Just break the loop */
 		}
 		iput(in);

 		next = realm->parent;
 		if (exceeded || !next)
 			break;
 		ceph_get_snap_realm(mdsc, next);
 		ceph_put_snap_realm(mdsc, realm);
 		realm = next;
 	}
 	ceph_put_snap_realm(mdsc, realm);
 	up_read(&mdsc->snap_rwsem);

 	return exceeded;
 }

 /*
  * ceph_quota_is_max_files_exceeded - check if we can create a new file
  * @inode:	directory where a new file is being created
  *
  * This functions returns true is max_files quota allows a new file to be
  * created.  It is necessary to walk through the snaprealm hierarchy (until the
  * FS root) to check all realms with quotas set.
  */
 bool ceph_quota_is_max_files_exceeded(struct inode *inode)
 {
 	if (!ceph_has_realms_with_quotas(inode))
 		return false;

 	WARN_ON(!S_ISDIR(inode->i_mode));

 	return check_quota_exceeded(inode, QUOTA_CHECK_MAX_FILES_OP, 0);
 }

 /*
  * ceph_quota_is_max_bytes_exceeded - check if we can write to a file
  * @inode:	inode being written
  * @newsize:	new size if write succeeds
  *
  * This functions returns true is max_bytes quota allows a file size to reach
  * @newsize; it returns false otherwise.
  */
 bool ceph_quota_is_max_bytes_exceeded(struct inode *inode, loff_t newsize)
 {
 	loff_t size = i_size_read(inode);

 	if (!ceph_has_realms_with_quotas(inode))
 		return false;

 	/* return immediately if we're decreasing file size */
 	if (newsize <= size)
 		return false;

 	return check_quota_exceeded(inode, QUOTA_CHECK_MAX_BYTES_OP, (newsize - size));
 }

 /*
  * ceph_quota_is_max_bytes_approaching - check if we're reaching max_bytes
  * @inode:	inode being written
  * @newsize:	new size if write succeeds
  *
  * This function returns true if the new file size @newsize will be consuming
  * more than 1/16th of the available quota space; it returns false otherwise.
  */
 bool ceph_quota_is_max_bytes_approaching(struct inode *inode, loff_t newsize)
 {
 	loff_t size = ceph_inode(inode)->i_reported_size;

 	if (!ceph_has_realms_with_quotas(inode))
 		return false;

 	/* return immediately if we're decreasing file size */
 	if (newsize <= size)
 		return false;

 	return check_quota_exceeded(inode, QUOTA_CHECK_MAX_BYTES_APPROACHING_OP,
 				    (newsize - size));
 }

 /*
  * ceph_quota_update_statfs - if root has quota update statfs with quota status
  * @fsc:	filesystem client instance
  * @buf:	statfs to update
  *
  * If the mounted filesystem root has max_bytes quota set, update the filesystem
  * statistics with the quota status.
  *
  * This function returns true if the stats have been updated, false otherwise.
  */
 bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf)
 {
 	struct ceph_mds_client *mdsc = fsc->mdsc;
 	struct ceph_inode_info *ci;
 	struct ceph_snap_realm *realm;
 	struct inode *in;
 	u64 total = 0, used, free;
 	bool is_updated = false;

 	down_read(&mdsc->snap_rwsem);
 	realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root));
 	up_read(&mdsc->snap_rwsem);
 	if (!realm)
 		return false;

 	spin_lock(&realm->inodes_with_caps_lock);
 	in = realm->inode ? igrab(realm->inode) : NULL;
 	spin_unlock(&realm->inodes_with_caps_lock);
 	if (in) {
 		ci = ceph_inode(in);
 		spin_lock(&ci->i_ceph_lock);
 		if (ci->i_max_bytes) {
 			total = ci->i_max_bytes >> CEPH_BLOCK_SHIFT;
 			used = ci->i_rbytes >> CEPH_BLOCK_SHIFT;
 			/* It is possible for a quota to be exceeded.
 			 * Report 'zero' in that case
 			 */
 			free = total > used ? total - used : 0;
 		}
 		spin_unlock(&ci->i_ceph_lock);
 		if (total) {
 			buf->f_blocks = total;
 			buf->f_bfree = free;
 			buf->f_bavail = free;
 			is_updated = true;
 		}
 		iput(in);
 	}
 	ceph_put_snap_realm(mdsc, realm);

 	return is_updated;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* quota.c - CephFS quota
	*
	* Copyright (C) 2017-2018 SUSE
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version 2
	* of the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/statfs.h>

	#include "super.h"
	#include "mds_client.h"

	void ceph_adjust_quota_realms_count(struct inode *inode, bool inc)
	{
	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
	if (inc)
	atomic64_inc(&mdsc->quotarealms_count);
	else
	atomic64_dec(&mdsc->quotarealms_count);
	}

	static inline bool ceph_has_realms_with_quotas(struct inode *inode)
	{
	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
	return atomic64_read(&mdsc->quotarealms_count) > 0;
	}

	void ceph_handle_quota(struct ceph_mds_client *mdsc,
	struct ceph_mds_session *session,
	struct ceph_msg *msg)
	{
	struct super_block *sb = mdsc->fsc->sb;
	struct ceph_mds_quota *h = msg->front.iov_base;
	struct ceph_vino vino;
	struct inode *inode;
	struct ceph_inode_info *ci;

	if (msg->front.iov_len < sizeof(*h)) {
	pr_err("%s corrupt message mds%d len %d\n", __func__,
	session->s_mds, (int)msg->front.iov_len);
	ceph_msg_dump(msg);
	return;
	}

	/* increment msg sequence number */
	mutex_lock(&session->s_mutex);
	session->s_seq++;
	mutex_unlock(&session->s_mutex);

	/* lookup inode */
	vino.ino = le64_to_cpu(h->ino);
	vino.snap = CEPH_NOSNAP;
	inode = ceph_find_inode(sb, vino);
	if (!inode) {
	pr_warn("Failed to find inode %llu\n", vino.ino);
	return;
	}
	ci = ceph_inode(inode);

	spin_lock(&ci->i_ceph_lock);
	ci->i_rbytes = le64_to_cpu(h->rbytes);
	ci->i_rfiles = le64_to_cpu(h->rfiles);
	ci->i_rsubdirs = le64_to_cpu(h->rsubdirs);
	__ceph_update_quota(ci, le64_to_cpu(h->max_bytes),
	le64_to_cpu(h->max_files));
	spin_unlock(&ci->i_ceph_lock);

	iput(inode);
	}

	/*
	* This function walks through the snaprealm for an inode and returns the
	* ceph_snap_realm for the first snaprealm that has quotas set (either max_files
	* or max_bytes). If the root is reached, return the root ceph_snap_realm
	* instead.
	*
	* Note that the caller is responsible for calling ceph_put_snap_realm() on the
	* returned realm.
	*/
	static struct ceph_snap_realm get_quota_realm(struct ceph_mds_client mdsc,
	struct inode *inode)
	{
	struct ceph_inode_info *ci = NULL;
	struct ceph_snap_realm realm, next;
	struct inode *in;
	bool has_quota;

	if (ceph_snap(inode) != CEPH_NOSNAP)
	return NULL;

	realm = ceph_inode(inode)->i_snap_realm;
	if (realm)
	ceph_get_snap_realm(mdsc, realm);
	else
	pr_err_ratelimited("get_quota_realm: ino (%llx.%llx) "
	"null i_snap_realm\n", ceph_vinop(inode));
	while (realm) {
	spin_lock(&realm->inodes_with_caps_lock);
	in = realm->inode ? igrab(realm->inode) : NULL;
	spin_unlock(&realm->inodes_with_caps_lock);
	if (!in)
	break;

	ci = ceph_inode(in);
	has_quota = __ceph_has_any_quota(ci);
	iput(in);

	next = realm->parent;
	if (has_quota \|\| !next)
	return realm;

	ceph_get_snap_realm(mdsc, next);
	ceph_put_snap_realm(mdsc, realm);
	realm = next;
	}
	if (realm)
	ceph_put_snap_realm(mdsc, realm);

	return NULL;
	}

	bool ceph_quota_is_same_realm(struct inode old, struct inode new)
	{
	struct ceph_mds_client *mdsc = ceph_inode_to_client(old)->mdsc;
	struct ceph_snap_realm old_realm, new_realm;
	bool is_same;

	down_read(&mdsc->snap_rwsem);
	old_realm = get_quota_realm(mdsc, old);
	new_realm = get_quota_realm(mdsc, new);
	is_same = (old_realm == new_realm);
	up_read(&mdsc->snap_rwsem);

	if (old_realm)
	ceph_put_snap_realm(mdsc, old_realm);
	if (new_realm)
	ceph_put_snap_realm(mdsc, new_realm);

	return is_same;
	}

	enum quota_check_op {
	QUOTA_CHECK_MAX_FILES_OP, /* check quota max_files limit */
	QUOTA_CHECK_MAX_BYTES_OP, /* check quota max_files limit */
	QUOTA_CHECK_MAX_BYTES_APPROACHING_OP /* check if quota max_files
	limit is approaching */
	};

	/*
	* check_quota_exceeded() will walk up the snaprealm hierarchy and, for each
	* realm, it will execute quota check operation defined by the 'op' parameter.
	* The snaprealm walk is interrupted if the quota check detects that the quota
	* is exceeded or if the root inode is reached.
	*/
	static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op,
	loff_t delta)
	{
	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
	struct ceph_inode_info *ci;
	struct ceph_snap_realm realm, next;
	struct inode *in;
	u64 max, rvalue;
	bool exceeded = false;

	if (ceph_snap(inode) != CEPH_NOSNAP)
	return false;

	down_read(&mdsc->snap_rwsem);
	realm = ceph_inode(inode)->i_snap_realm;
	if (realm)
	ceph_get_snap_realm(mdsc, realm);
	else
	pr_err_ratelimited("check_quota_exceeded: ino (%llx.%llx) "
	"null i_snap_realm\n", ceph_vinop(inode));
	while (realm) {
	spin_lock(&realm->inodes_with_caps_lock);
	in = realm->inode ? igrab(realm->inode) : NULL;
	spin_unlock(&realm->inodes_with_caps_lock);
	if (!in)
	break;

	ci = ceph_inode(in);
	spin_lock(&ci->i_ceph_lock);
	if (op == QUOTA_CHECK_MAX_FILES_OP) {
	max = ci->i_max_files;
	rvalue = ci->i_rfiles + ci->i_rsubdirs;
	} else {
	max = ci->i_max_bytes;
	rvalue = ci->i_rbytes;
	}
	spin_unlock(&ci->i_ceph_lock);
	switch (op) {
	case QUOTA_CHECK_MAX_FILES_OP:
	exceeded = (max && (rvalue >= max));
	break;
	case QUOTA_CHECK_MAX_BYTES_OP:
	exceeded = (max && (rvalue + delta > max));
	break;
	case QUOTA_CHECK_MAX_BYTES_APPROACHING_OP:
	if (max) {
	if (rvalue >= max)
	exceeded = true;
	else {
	/*
	* when we're writing more that 1/16th
	* of the available space
	*/
	exceeded =
	(((max - rvalue) >> 4) < delta);
	}
	}
	break;
	default:
	/* Shouldn't happen */
	pr_warn("Invalid quota check op (%d)\n", op);
	exceeded = true; /* Just break the loop */
	}
	iput(in);

	next = realm->parent;
	if (exceeded \|\| !next)
	break;
	ceph_get_snap_realm(mdsc, next);
	ceph_put_snap_realm(mdsc, realm);
	realm = next;
	}
	ceph_put_snap_realm(mdsc, realm);
	up_read(&mdsc->snap_rwsem);

	return exceeded;
	}

	/*
	* ceph_quota_is_max_files_exceeded - check if we can create a new file
	* @inode: directory where a new file is being created
	*
	* This functions returns true is max_files quota allows a new file to be
	* created. It is necessary to walk through the snaprealm hierarchy (until the
	* FS root) to check all realms with quotas set.
	*/
	bool ceph_quota_is_max_files_exceeded(struct inode *inode)
	{
	if (!ceph_has_realms_with_quotas(inode))
	return false;

	WARN_ON(!S_ISDIR(inode->i_mode));

	return check_quota_exceeded(inode, QUOTA_CHECK_MAX_FILES_OP, 0);
	}

	/*
	* ceph_quota_is_max_bytes_exceeded - check if we can write to a file
	* @inode: inode being written
	* @newsize: new size if write succeeds
	*
	* This functions returns true is max_bytes quota allows a file size to reach
	* @newsize; it returns false otherwise.
	*/
	bool ceph_quota_is_max_bytes_exceeded(struct inode *inode, loff_t newsize)
	{
	loff_t size = i_size_read(inode);

	if (!ceph_has_realms_with_quotas(inode))
	return false;

	/* return immediately if we're decreasing file size */
	if (newsize <= size)
	return false;

	return check_quota_exceeded(inode, QUOTA_CHECK_MAX_BYTES_OP, (newsize - size));
	}

	/*
	* ceph_quota_is_max_bytes_approaching - check if we're reaching max_bytes
	* @inode: inode being written
	* @newsize: new size if write succeeds
	*
	* This function returns true if the new file size @newsize will be consuming
	* more than 1/16th of the available quota space; it returns false otherwise.
	*/
	bool ceph_quota_is_max_bytes_approaching(struct inode *inode, loff_t newsize)
	{
	loff_t size = ceph_inode(inode)->i_reported_size;

	if (!ceph_has_realms_with_quotas(inode))
	return false;

	/* return immediately if we're decreasing file size */
	if (newsize <= size)
	return false;

	return check_quota_exceeded(inode, QUOTA_CHECK_MAX_BYTES_APPROACHING_OP,
	(newsize - size));
	}

	/*
	* ceph_quota_update_statfs - if root has quota update statfs with quota status
	* @fsc: filesystem client instance
	* @buf: statfs to update
	*
	* If the mounted filesystem root has max_bytes quota set, update the filesystem
	* statistics with the quota status.
	*
	* This function returns true if the stats have been updated, false otherwise.
	*/
	bool ceph_quota_update_statfs(struct ceph_fs_client fsc, struct kstatfs buf)
	{
	struct ceph_mds_client *mdsc = fsc->mdsc;
	struct ceph_inode_info *ci;
	struct ceph_snap_realm *realm;
	struct inode *in;
	u64 total = 0, used, free;
	bool is_updated = false;

	down_read(&mdsc->snap_rwsem);
	realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root));
	up_read(&mdsc->snap_rwsem);
	if (!realm)
	return false;

	spin_lock(&realm->inodes_with_caps_lock);
	in = realm->inode ? igrab(realm->inode) : NULL;
	spin_unlock(&realm->inodes_with_caps_lock);
	if (in) {
	ci = ceph_inode(in);
	spin_lock(&ci->i_ceph_lock);
	if (ci->i_max_bytes) {
	total = ci->i_max_bytes >> CEPH_BLOCK_SHIFT;
	used = ci->i_rbytes >> CEPH_BLOCK_SHIFT;
	/* It is possible for a quota to be exceeded.
	* Report 'zero' in that case
	*/
	free = total > used ? total - used : 0;
	}
	spin_unlock(&ci->i_ceph_lock);
	if (total) {
	buf->f_blocks = total;
	buf->f_bfree = free;
	buf->f_bavail = free;
	is_updated = true;
	}
	iput(in);
	}
	ceph_put_snap_realm(mdsc, realm);

	return is_updated;
	}