// 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 "super.h"
#include "mds_client.h"
static inline bool ceph_has_quota(struct ceph_inode_info *ci)
{
return (ci && (ci->i_max_files || ci->i_max_bytes));
}
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);
ci->i_max_bytes = le64_to_cpu(h->max_bytes);
ci->i_max_files = 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 ceph_vino vino;
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) {
vino.ino = realm->ino;
vino.snap = CEPH_NOSNAP;
in = ceph_find_inode(inode->i_sb, vino);
if (!in) {
pr_warn("Failed to find inode for %llu\n", vino.ino);
break;
}
ci = ceph_inode(in);
has_quota = ceph_has_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 ceph_vino vino;
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) {
vino.ino = realm->ino;
vino.snap = CEPH_NOSNAP;
in = ceph_find_inode(inode->i_sb, vino);
if (!in) {
pr_warn("Failed to find inode for %llu\n", vino.ino);
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)
{
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);
/* 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;
/* 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));
}
