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-rw-r--r--fs/ceph/quota.c535
1 files changed, 535 insertions, 0 deletions
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
new file mode 100644
index 000000000..f7fcf7f08
--- /dev/null
+++ b/fs/ceph/quota.c
@@ -0,0 +1,535 @@
+// 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;
+ /* MDS stray dirs have no quota realms */
+ if (ceph_vino_is_reserved(ceph_inode(inode)->i_vino))
+ 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 (!ceph_inc_mds_stopping_blocker(mdsc, session))
+ return;
+
+ 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);
+ goto out;
+ }
+
+ /* 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);
+ goto out;
+ }
+ 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);
+out:
+ ceph_dec_mds_stopping_blocker(mdsc);
+}
+
+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 (max_files,
+ * max_bytes, or any, depending on the 'which_quota' argument). 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,
+ enum quota_get_realm which_quota,
+ 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_quota(ci, which_quota);
+ 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, QUOTA_GET_ANY, true);
+ new_realm = get_quota_realm(mdsc, new, QUOTA_GET_ANY, 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 */
+ }
+ 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),
+ QUOTA_GET_MAX_BYTES, 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;
+ /* For quota size less than 4MB, use 4KB block size */
+ if (!total) {
+ total = ci->i_max_bytes >> CEPH_4K_BLOCK_SHIFT;
+ used = ci->i_rbytes >> CEPH_4K_BLOCK_SHIFT;
+ buf->f_frsize = 1 << CEPH_4K_BLOCK_SHIFT;
+ }
+ /* It is possible for a quota to be exceeded.
+ * Report 'zero' in that case
+ */
+ free = total > used ? total - used : 0;
+ /* For quota size less than 4KB, report the
+ * total=used=4KB,free=0 when quota is full
+ * and total=free=4KB, used=0 otherwise */
+ if (!total) {
+ total = 1;
+ free = ci->i_max_bytes > ci->i_rbytes ? 1 : 0;
+ buf->f_frsize = 1 << CEPH_4K_BLOCK_SHIFT;
+ }
+ }
+ 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;
+}
+