linux/fs/ceph/quota.c
Luis Henriques 6646ea1c8e Revert "ceph: allow rename operation under different quota realms"
This reverts commit dffdcd7145.

When doing a rename across quota realms, there's a corner case that isn't
handled correctly.  Here's a testcase:

  mkdir files limit
  truncate files/file -s 10G
  setfattr limit -n ceph.quota.max_bytes -v 1000000
  mv files limit/

The above will succeed because ftruncate(2) won't immediately notify the
MDSs with the new file size, and thus the quota realms stats won't be
updated.

Since the possible fixes for this issue would have a huge performance impact,
the solution for now is to simply revert to returning -EXDEV when doing a cross
quota realms rename.

URL: https://tracker.ceph.com/issues/48203
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-12-14 23:21:47 +01:00

519 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* quota.c - CephFS quota
*
* Copyright (C) 2017-2018 SUSE
*/
#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_sb_to_mdsc(inode->i_sb);
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 super_block *sb = inode->i_sb;
struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(sb);
struct inode *root = d_inode(sb->s_root);
if (atomic64_read(&mdsc->quotarealms_count) > 0)
return true;
/* if root is the real CephFS root, we don't have quota realms */
if (root && ceph_ino(root) == CEPH_INO_ROOT)
return false;
/* otherwise, we can't know for sure */
return true;
}
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);
inc_session_sequence(session);
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);
/* avoid calling iput_final() in dispatch thread */
ceph_async_iput(inode);
}
static struct ceph_quotarealm_inode *
find_quotarealm_inode(struct ceph_mds_client *mdsc, u64 ino)
{
struct ceph_quotarealm_inode *qri = NULL;
struct rb_node **node, *parent = NULL;
mutex_lock(&mdsc->quotarealms_inodes_mutex);
node = &(mdsc->quotarealms_inodes.rb_node);
while (*node) {
parent = *node;
qri = container_of(*node, struct ceph_quotarealm_inode, node);
if (ino < qri->ino)
node = &((*node)->rb_left);
else if (ino > qri->ino)
node = &((*node)->rb_right);
else
break;
}
if (!qri || (qri->ino != ino)) {
/* Not found, create a new one and insert it */
qri = kmalloc(sizeof(*qri), GFP_KERNEL);
if (qri) {
qri->ino = ino;
qri->inode = NULL;
qri->timeout = 0;
mutex_init(&qri->mutex);
rb_link_node(&qri->node, parent, node);
rb_insert_color(&qri->node, &mdsc->quotarealms_inodes);
} else
pr_warn("Failed to alloc quotarealms_inode\n");
}
mutex_unlock(&mdsc->quotarealms_inodes_mutex);
return qri;
}
/*
* This function will try to lookup a realm inode which isn't visible in the
* filesystem mountpoint. A list of these kind of inodes (not visible) is
* maintained in the mdsc and freed only when the filesystem is umounted.
*
* Note that these inodes are kept in this list even if the lookup fails, which
* allows to prevent useless lookup requests.
*/
static struct inode *lookup_quotarealm_inode(struct ceph_mds_client *mdsc,
struct super_block *sb,
struct ceph_snap_realm *realm)
{
struct ceph_quotarealm_inode *qri;
struct inode *in;
qri = find_quotarealm_inode(mdsc, realm->ino);
if (!qri)
return NULL;
mutex_lock(&qri->mutex);
if (qri->inode && ceph_is_any_caps(qri->inode)) {
/* A request has already returned the inode */
mutex_unlock(&qri->mutex);
return qri->inode;
}
/* Check if this inode lookup has failed recently */
if (qri->timeout &&
time_before_eq(jiffies, qri->timeout)) {
mutex_unlock(&qri->mutex);
return NULL;
}
if (qri->inode) {
/* get caps */
int ret = __ceph_do_getattr(qri->inode, NULL,
CEPH_STAT_CAP_INODE, true);
if (ret >= 0)
in = qri->inode;
else
in = ERR_PTR(ret);
} else {
in = ceph_lookup_inode(sb, realm->ino);
}
if (IS_ERR(in)) {
dout("Can't lookup inode %llx (err: %ld)\n",
realm->ino, PTR_ERR(in));
qri->timeout = jiffies + msecs_to_jiffies(60 * 1000); /* XXX */
} else {
qri->timeout = 0;
qri->inode = in;
}
mutex_unlock(&qri->mutex);
return in;
}
void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc)
{
struct ceph_quotarealm_inode *qri;
struct rb_node *node;
/*
* It should now be safe to clean quotarealms_inode tree without holding
* mdsc->quotarealms_inodes_mutex...
*/
mutex_lock(&mdsc->quotarealms_inodes_mutex);
while (!RB_EMPTY_ROOT(&mdsc->quotarealms_inodes)) {
node = rb_first(&mdsc->quotarealms_inodes);
qri = rb_entry(node, struct ceph_quotarealm_inode, node);
rb_erase(node, &mdsc->quotarealms_inodes);
iput(qri->inode);
kfree(qri);
}
mutex_unlock(&mdsc->quotarealms_inodes_mutex);
}
/*
* 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.
*
* Callers of this function need to hold mdsc->snap_rwsem. However, if there's
* a need to do an inode lookup, this rwsem will be temporarily dropped. Hence
* the 'retry' argument: if rwsem needs to be dropped and 'retry' is 'false'
* this function will return -EAGAIN; otherwise, the snaprealms walk-through
* will be restarted.
*/
static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc,
struct inode *inode, bool retry)
{
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;
restart:
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) {
bool has_inode;
spin_lock(&realm->inodes_with_caps_lock);
has_inode = realm->inode;
in = has_inode ? igrab(realm->inode) : NULL;
spin_unlock(&realm->inodes_with_caps_lock);
if (has_inode && !in)
break;
if (!in) {
up_read(&mdsc->snap_rwsem);
in = lookup_quotarealm_inode(mdsc, inode->i_sb, realm);
down_read(&mdsc->snap_rwsem);
if (IS_ERR_OR_NULL(in))
break;
ceph_put_snap_realm(mdsc, realm);
if (!retry)
return ERR_PTR(-EAGAIN);
goto restart;
}
ci = ceph_inode(in);
has_quota = __ceph_has_any_quota(ci);
/* avoid calling iput_final() while holding mdsc->snap_rwsem */
ceph_async_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_sb_to_mdsc(old->i_sb);
struct ceph_snap_realm *old_realm, *new_realm;
bool is_same;
restart:
/*
* We need to lookup 2 quota realms atomically, i.e. with snap_rwsem.
* However, get_quota_realm may drop it temporarily. By setting the
* 'retry' parameter to 'false', we'll get -EAGAIN if the rwsem was
* dropped and we can then restart the whole operation.
*/
down_read(&mdsc->snap_rwsem);
old_realm = get_quota_realm(mdsc, old, true);
new_realm = get_quota_realm(mdsc, new, false);
if (PTR_ERR(new_realm) == -EAGAIN) {
up_read(&mdsc->snap_rwsem);
if (old_realm)
ceph_put_snap_realm(mdsc, old_realm);
goto restart;
}
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_sb_to_mdsc(inode->i_sb);
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);
restart:
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) {
bool has_inode;
spin_lock(&realm->inodes_with_caps_lock);
has_inode = realm->inode;
in = has_inode ? igrab(realm->inode) : NULL;
spin_unlock(&realm->inodes_with_caps_lock);
if (has_inode && !in)
break;
if (!in) {
up_read(&mdsc->snap_rwsem);
in = lookup_quotarealm_inode(mdsc, inode->i_sb, realm);
down_read(&mdsc->snap_rwsem);
if (IS_ERR_OR_NULL(in))
break;
ceph_put_snap_realm(mdsc, realm);
goto restart;
}
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:
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 */
}
/* avoid calling iput_final() while holding mdsc->snap_rwsem */
ceph_async_iput(in);
next = realm->parent;
if (exceeded || !next)
break;
ceph_get_snap_realm(mdsc, next);
ceph_put_snap_realm(mdsc, realm);
realm = next;
}
if (realm)
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, 1);
}
/*
* 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), true);
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;
}