diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 9049c2a3e972f499ea1371e8c4b8112ead98a6e3..5dee98b4cfde26ca0f4539c884e2a74519ef3c2e 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -4125,6 +4125,8 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc)
mdsc->max_sessions = 0;
mdsc->stopping = 0;
atomic64_set(&mdsc->quotarealms_count, 0);
+ mdsc->quotarealms_inodes = RB_ROOT;
+ mutex_init(&mdsc->quotarealms_inodes_mutex);
mdsc->last_snap_seq = 0;
init_rwsem(&mdsc->snap_rwsem);
mdsc->snap_realms = RB_ROOT;
@@ -4216,6 +4218,8 @@ void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
* their inode/dcache refs
*/
ceph_msgr_flush();
+
+ ceph_cleanup_quotarealms_inodes(mdsc);
}
/*
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 50385a481fdbb9b2764257ddec68cc5acb4a9ff3..3f0029aa8a39793cee59331c7242737d4892cb39 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -325,6 +325,18 @@ struct ceph_snapid_map {
unsigned long last_used;
};
+/*
+ * node for list of quotarealm inodes that are not visible from the filesystem
+ * mountpoint, but required to handle, e.g. quotas.
+ */
+struct ceph_quotarealm_inode {
+ struct rb_node node;
+ u64 ino;
+ unsigned long timeout; /* last time a lookup failed for this inode */
+ struct mutex mutex;
+ struct inode *inode;
+};
+
/*
* mds client state
*/
@@ -344,6 +356,12 @@ struct ceph_mds_client {
int stopping; /* true if shutting down */
atomic64_t quotarealms_count; /* # realms with quota */
+ /*
+ * We keep a list of inodes we don't see in the mountpoint but that we
+ * need to track quota realms.
+ */
+ struct rb_root quotarealms_inodes;
+ struct mutex quotarealms_inodes_mutex;
/*
* snap_rwsem will cover cap linkage into snaprealms, and
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index 9455d3aef0c3c1b50f5be96e3a804424e55597b4..c4522212872c9fe5f5a3dd4515b19e688cce805a 100644
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -22,7 +22,16 @@ void ceph_adjust_quota_realms_count(struct inode *inode, bool inc)
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;
+ struct super_block *sb = mdsc->fsc->sb;
+
+ if (atomic64_read(&mdsc->quotarealms_count) > 0)
+ return true;
+ /* if root is the real CephFS root, we don't have quota realms */
+ if (sb->s_root->d_inode &&
+ (sb->s_root->d_inode->i_ino == CEPH_INO_ROOT))
+ return false;
+ /* otherwise, we can't know for sure */
+ return true;
}
void ceph_handle_quota(struct ceph_mds_client *mdsc,
@@ -68,6 +77,108 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
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) {
+ /* 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;
+ }
+ in = ceph_lookup_inode(sb, realm->ino);
+ if (IS_ERR(in)) {
+ pr_warn("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
@@ -76,9 +187,15 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
*
* 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)
+ struct inode *inode, bool retry)
{
struct ceph_inode_info *ci = NULL;
struct ceph_snap_realm *realm, *next;
@@ -88,6 +205,7 @@ static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc,
if (ceph_snap(inode) != CEPH_NOSNAP)
return NULL;
+restart:
realm = ceph_inode(inode)->i_snap_realm;
if (realm)
ceph_get_snap_realm(mdsc, realm);
@@ -95,11 +213,25 @@ static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc,
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);
- in = realm->inode ? igrab(realm->inode) : NULL;
+ has_inode = realm->inode;
+ in = has_inode ? igrab(realm->inode) : NULL;
spin_unlock(&realm->inodes_with_caps_lock);
- if (!in)
+ 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);
@@ -125,9 +257,22 @@ bool ceph_quota_is_same_realm(struct inode *old, struct inode *new)
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);
- new_realm = get_quota_realm(mdsc, new);
+ 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);
@@ -166,6 +311,7 @@ static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op,
return false;
down_read(&mdsc->snap_rwsem);
+restart:
realm = ceph_inode(inode)->i_snap_realm;
if (realm)
ceph_get_snap_realm(mdsc, realm);
@@ -173,12 +319,23 @@ static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op,
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);
- in = realm->inode ? igrab(realm->inode) : NULL;
+ has_inode = realm->inode;
+ in = has_inode ? igrab(realm->inode) : NULL;
spin_unlock(&realm->inodes_with_caps_lock);
- if (!in)
+ 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) {
@@ -314,7 +471,7 @@ bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf)
bool is_updated = false;
down_read(&mdsc->snap_rwsem);
- realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root));
+ realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root), true);
up_read(&mdsc->snap_rwsem);
if (!realm)
return false;
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 976f200164f99a6bae53759fe106505094f1cfbe..a4b0da31d1996921820bc3ff32f163595768be1d 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1133,5 +1133,6 @@ extern bool ceph_quota_is_max_bytes_approaching(struct inode *inode,
loff_t newlen);
extern bool ceph_quota_update_statfs(struct ceph_fs_client *fsc,
struct kstatfs *buf);
+extern void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc);
#endif /* _FS_CEPH_SUPER_H */