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-rw-r--r--fs/ceph/export.c584
1 files changed, 584 insertions, 0 deletions
diff --git a/fs/ceph/export.c b/fs/ceph/export.c
new file mode 100644
index 000000000..f780e4e0d
--- /dev/null
+++ b/fs/ceph/export.c
@@ -0,0 +1,584 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/exportfs.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+#include "super.h"
+#include "mds_client.h"
+
+/*
+ * Basic fh
+ */
+struct ceph_nfs_fh {
+ u64 ino;
+} __attribute__ ((packed));
+
+/*
+ * Larger fh that includes parent ino.
+ */
+struct ceph_nfs_confh {
+ u64 ino, parent_ino;
+} __attribute__ ((packed));
+
+/*
+ * fh for snapped inode
+ */
+struct ceph_nfs_snapfh {
+ u64 ino;
+ u64 snapid;
+ u64 parent_ino;
+ u32 hash;
+} __attribute__ ((packed));
+
+static int ceph_encode_snapfh(struct inode *inode, u32 *rawfh, int *max_len,
+ struct inode *parent_inode)
+{
+ static const int snap_handle_length =
+ sizeof(struct ceph_nfs_snapfh) >> 2;
+ struct ceph_nfs_snapfh *sfh = (void *)rawfh;
+ u64 snapid = ceph_snap(inode);
+ int ret;
+ bool no_parent = true;
+
+ if (*max_len < snap_handle_length) {
+ *max_len = snap_handle_length;
+ ret = FILEID_INVALID;
+ goto out;
+ }
+
+ ret = -EINVAL;
+ if (snapid != CEPH_SNAPDIR) {
+ struct inode *dir;
+ struct dentry *dentry = d_find_alias(inode);
+ if (!dentry)
+ goto out;
+
+ rcu_read_lock();
+ dir = d_inode_rcu(dentry->d_parent);
+ if (ceph_snap(dir) != CEPH_SNAPDIR) {
+ sfh->parent_ino = ceph_ino(dir);
+ sfh->hash = ceph_dentry_hash(dir, dentry);
+ no_parent = false;
+ }
+ rcu_read_unlock();
+ dput(dentry);
+ }
+
+ if (no_parent) {
+ if (!S_ISDIR(inode->i_mode))
+ goto out;
+ sfh->parent_ino = sfh->ino;
+ sfh->hash = 0;
+ }
+ sfh->ino = ceph_ino(inode);
+ sfh->snapid = snapid;
+
+ *max_len = snap_handle_length;
+ ret = FILEID_BTRFS_WITH_PARENT;
+out:
+ dout("encode_snapfh %llx.%llx ret=%d\n", ceph_vinop(inode), ret);
+ return ret;
+}
+
+static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
+ struct inode *parent_inode)
+{
+ static const int handle_length =
+ sizeof(struct ceph_nfs_fh) >> 2;
+ static const int connected_handle_length =
+ sizeof(struct ceph_nfs_confh) >> 2;
+ int type;
+
+ if (ceph_snap(inode) != CEPH_NOSNAP)
+ return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode);
+
+ if (parent_inode && (*max_len < connected_handle_length)) {
+ *max_len = connected_handle_length;
+ return FILEID_INVALID;
+ } else if (*max_len < handle_length) {
+ *max_len = handle_length;
+ return FILEID_INVALID;
+ }
+
+ if (parent_inode) {
+ struct ceph_nfs_confh *cfh = (void *)rawfh;
+ dout("encode_fh %llx with parent %llx\n",
+ ceph_ino(inode), ceph_ino(parent_inode));
+ cfh->ino = ceph_ino(inode);
+ cfh->parent_ino = ceph_ino(parent_inode);
+ *max_len = connected_handle_length;
+ type = FILEID_INO32_GEN_PARENT;
+ } else {
+ struct ceph_nfs_fh *fh = (void *)rawfh;
+ dout("encode_fh %llx\n", ceph_ino(inode));
+ fh->ino = ceph_ino(inode);
+ *max_len = handle_length;
+ type = FILEID_INO32_GEN;
+ }
+ return type;
+}
+
+static struct inode *__lookup_inode(struct super_block *sb, u64 ino)
+{
+ struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
+ struct inode *inode;
+ struct ceph_vino vino;
+ int err;
+
+ vino.ino = ino;
+ vino.snap = CEPH_NOSNAP;
+
+ if (ceph_vino_is_reserved(vino))
+ return ERR_PTR(-ESTALE);
+
+ inode = ceph_find_inode(sb, vino);
+ if (!inode) {
+ struct ceph_mds_request *req;
+ int mask;
+
+ req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
+ USE_ANY_MDS);
+ if (IS_ERR(req))
+ return ERR_CAST(req);
+
+ mask = CEPH_STAT_CAP_INODE;
+ if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
+ mask |= CEPH_CAP_XATTR_SHARED;
+ req->r_args.lookupino.mask = cpu_to_le32(mask);
+
+ req->r_ino1 = vino;
+ req->r_num_caps = 1;
+ err = ceph_mdsc_do_request(mdsc, NULL, req);
+ inode = req->r_target_inode;
+ if (inode)
+ ihold(inode);
+ ceph_mdsc_put_request(req);
+ if (!inode)
+ return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE);
+ } else {
+ if (ceph_inode_is_shutdown(inode)) {
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ }
+ return inode;
+}
+
+struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
+{
+ struct inode *inode = __lookup_inode(sb, ino);
+ if (IS_ERR(inode))
+ return inode;
+ if (inode->i_nlink == 0) {
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ return inode;
+}
+
+static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
+{
+ struct inode *inode = __lookup_inode(sb, ino);
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ int err;
+
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ /* We need LINK caps to reliably check i_nlink */
+ err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false);
+ if (err) {
+ iput(inode);
+ return ERR_PTR(err);
+ }
+ /* -ESTALE if inode as been unlinked and no file is open */
+ if ((inode->i_nlink == 0) && !__ceph_is_file_opened(ci)) {
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ return d_obtain_alias(inode);
+}
+
+static struct dentry *__snapfh_to_dentry(struct super_block *sb,
+ struct ceph_nfs_snapfh *sfh,
+ bool want_parent)
+{
+ struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
+ struct ceph_mds_request *req;
+ struct inode *inode;
+ struct ceph_vino vino;
+ int mask;
+ int err;
+ bool unlinked = false;
+
+ if (want_parent) {
+ vino.ino = sfh->parent_ino;
+ if (sfh->snapid == CEPH_SNAPDIR)
+ vino.snap = CEPH_NOSNAP;
+ else if (sfh->ino == sfh->parent_ino)
+ vino.snap = CEPH_SNAPDIR;
+ else
+ vino.snap = sfh->snapid;
+ } else {
+ vino.ino = sfh->ino;
+ vino.snap = sfh->snapid;
+ }
+
+ if (ceph_vino_is_reserved(vino))
+ return ERR_PTR(-ESTALE);
+
+ inode = ceph_find_inode(sb, vino);
+ if (inode) {
+ if (ceph_inode_is_shutdown(inode)) {
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ return d_obtain_alias(inode);
+ }
+
+ req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
+ USE_ANY_MDS);
+ if (IS_ERR(req))
+ return ERR_CAST(req);
+
+ mask = CEPH_STAT_CAP_INODE;
+ if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
+ mask |= CEPH_CAP_XATTR_SHARED;
+ req->r_args.lookupino.mask = cpu_to_le32(mask);
+ if (vino.snap < CEPH_NOSNAP) {
+ req->r_args.lookupino.snapid = cpu_to_le64(vino.snap);
+ if (!want_parent && sfh->ino != sfh->parent_ino) {
+ req->r_args.lookupino.parent =
+ cpu_to_le64(sfh->parent_ino);
+ req->r_args.lookupino.hash =
+ cpu_to_le32(sfh->hash);
+ }
+ }
+
+ req->r_ino1 = vino;
+ req->r_num_caps = 1;
+ err = ceph_mdsc_do_request(mdsc, NULL, req);
+ inode = req->r_target_inode;
+ if (inode) {
+ if (vino.snap == CEPH_SNAPDIR) {
+ if (inode->i_nlink == 0)
+ unlinked = true;
+ inode = ceph_get_snapdir(inode);
+ } else if (ceph_snap(inode) == vino.snap) {
+ ihold(inode);
+ } else {
+ /* mds does not support lookup snapped inode */
+ inode = ERR_PTR(-EOPNOTSUPP);
+ }
+ } else {
+ inode = ERR_PTR(-ESTALE);
+ }
+ ceph_mdsc_put_request(req);
+
+ if (want_parent) {
+ dout("snapfh_to_parent %llx.%llx\n err=%d\n",
+ vino.ino, vino.snap, err);
+ } else {
+ dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d",
+ vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err);
+ }
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ /* see comments in ceph_get_parent() */
+ return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode);
+}
+
+/*
+ * convert regular fh to dentry
+ */
+static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
+ struct fid *fid,
+ int fh_len, int fh_type)
+{
+ struct ceph_nfs_fh *fh = (void *)fid->raw;
+
+ if (fh_type == FILEID_BTRFS_WITH_PARENT) {
+ struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
+ return __snapfh_to_dentry(sb, sfh, false);
+ }
+
+ if (fh_type != FILEID_INO32_GEN &&
+ fh_type != FILEID_INO32_GEN_PARENT)
+ return NULL;
+ if (fh_len < sizeof(*fh) / 4)
+ return NULL;
+
+ dout("fh_to_dentry %llx\n", fh->ino);
+ return __fh_to_dentry(sb, fh->ino);
+}
+
+static struct dentry *__get_parent(struct super_block *sb,
+ struct dentry *child, u64 ino)
+{
+ struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
+ struct ceph_mds_request *req;
+ struct inode *inode;
+ int mask;
+ int err;
+
+ req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
+ USE_ANY_MDS);
+ if (IS_ERR(req))
+ return ERR_CAST(req);
+
+ if (child) {
+ req->r_inode = d_inode(child);
+ ihold(d_inode(child));
+ } else {
+ req->r_ino1 = (struct ceph_vino) {
+ .ino = ino,
+ .snap = CEPH_NOSNAP,
+ };
+ }
+
+ mask = CEPH_STAT_CAP_INODE;
+ if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
+ mask |= CEPH_CAP_XATTR_SHARED;
+ req->r_args.getattr.mask = cpu_to_le32(mask);
+
+ req->r_num_caps = 1;
+ err = ceph_mdsc_do_request(mdsc, NULL, req);
+ if (err) {
+ ceph_mdsc_put_request(req);
+ return ERR_PTR(err);
+ }
+
+ inode = req->r_target_inode;
+ if (inode)
+ ihold(inode);
+ ceph_mdsc_put_request(req);
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+
+ return d_obtain_alias(inode);
+}
+
+static struct dentry *ceph_get_parent(struct dentry *child)
+{
+ struct inode *inode = d_inode(child);
+ struct dentry *dn;
+
+ if (ceph_snap(inode) != CEPH_NOSNAP) {
+ struct inode* dir;
+ bool unlinked = false;
+ /* do not support non-directory */
+ if (!d_is_dir(child)) {
+ dn = ERR_PTR(-EINVAL);
+ goto out;
+ }
+ dir = __lookup_inode(inode->i_sb, ceph_ino(inode));
+ if (IS_ERR(dir)) {
+ dn = ERR_CAST(dir);
+ goto out;
+ }
+ /* There can be multiple paths to access snapped inode.
+ * For simplicity, treat snapdir of head inode as parent */
+ if (ceph_snap(inode) != CEPH_SNAPDIR) {
+ struct inode *snapdir = ceph_get_snapdir(dir);
+ if (dir->i_nlink == 0)
+ unlinked = true;
+ iput(dir);
+ if (IS_ERR(snapdir)) {
+ dn = ERR_CAST(snapdir);
+ goto out;
+ }
+ dir = snapdir;
+ }
+ /* If directory has already been deleted, futher get_parent
+ * will fail. Do not mark snapdir dentry as disconnected,
+ * this prevent exportfs from doing futher get_parent. */
+ if (unlinked)
+ dn = d_obtain_root(dir);
+ else
+ dn = d_obtain_alias(dir);
+ } else {
+ dn = __get_parent(child->d_sb, child, 0);
+ }
+out:
+ dout("get_parent %p ino %llx.%llx err=%ld\n",
+ child, ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn));
+ return dn;
+}
+
+/*
+ * convert regular fh to parent
+ */
+static struct dentry *ceph_fh_to_parent(struct super_block *sb,
+ struct fid *fid,
+ int fh_len, int fh_type)
+{
+ struct ceph_nfs_confh *cfh = (void *)fid->raw;
+ struct dentry *dentry;
+
+ if (fh_type == FILEID_BTRFS_WITH_PARENT) {
+ struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
+ return __snapfh_to_dentry(sb, sfh, true);
+ }
+
+ if (fh_type != FILEID_INO32_GEN_PARENT)
+ return NULL;
+ if (fh_len < sizeof(*cfh) / 4)
+ return NULL;
+
+ dout("fh_to_parent %llx\n", cfh->parent_ino);
+ dentry = __get_parent(sb, NULL, cfh->ino);
+ if (unlikely(dentry == ERR_PTR(-ENOENT)))
+ dentry = __fh_to_dentry(sb, cfh->parent_ino);
+ return dentry;
+}
+
+static int __get_snap_name(struct dentry *parent, char *name,
+ struct dentry *child)
+{
+ struct inode *inode = d_inode(child);
+ struct inode *dir = d_inode(parent);
+ struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+ struct ceph_mds_request *req = NULL;
+ char *last_name = NULL;
+ unsigned next_offset = 2;
+ int err = -EINVAL;
+
+ if (ceph_ino(inode) != ceph_ino(dir))
+ goto out;
+ if (ceph_snap(inode) == CEPH_SNAPDIR) {
+ if (ceph_snap(dir) == CEPH_NOSNAP) {
+ strcpy(name, fsc->mount_options->snapdir_name);
+ err = 0;
+ }
+ goto out;
+ }
+ if (ceph_snap(dir) != CEPH_SNAPDIR)
+ goto out;
+
+ while (1) {
+ struct ceph_mds_reply_info_parsed *rinfo;
+ struct ceph_mds_reply_dir_entry *rde;
+ int i;
+
+ req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP,
+ USE_AUTH_MDS);
+ if (IS_ERR(req)) {
+ err = PTR_ERR(req);
+ req = NULL;
+ goto out;
+ }
+ err = ceph_alloc_readdir_reply_buffer(req, inode);
+ if (err)
+ goto out;
+
+ req->r_direct_mode = USE_AUTH_MDS;
+ req->r_readdir_offset = next_offset;
+ req->r_args.readdir.flags =
+ cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
+ if (last_name) {
+ req->r_path2 = last_name;
+ last_name = NULL;
+ }
+
+ req->r_inode = dir;
+ ihold(dir);
+ req->r_dentry = dget(parent);
+
+ inode_lock(dir);
+ err = ceph_mdsc_do_request(fsc->mdsc, NULL, req);
+ inode_unlock(dir);
+
+ if (err < 0)
+ goto out;
+
+ rinfo = &req->r_reply_info;
+ for (i = 0; i < rinfo->dir_nr; i++) {
+ rde = rinfo->dir_entries + i;
+ BUG_ON(!rde->inode.in);
+ if (ceph_snap(inode) ==
+ le64_to_cpu(rde->inode.in->snapid)) {
+ memcpy(name, rde->name, rde->name_len);
+ name[rde->name_len] = '\0';
+ err = 0;
+ goto out;
+ }
+ }
+
+ if (rinfo->dir_end)
+ break;
+
+ BUG_ON(rinfo->dir_nr <= 0);
+ rde = rinfo->dir_entries + (rinfo->dir_nr - 1);
+ next_offset += rinfo->dir_nr;
+ last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL);
+ if (!last_name) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ ceph_mdsc_put_request(req);
+ req = NULL;
+ }
+ err = -ENOENT;
+out:
+ if (req)
+ ceph_mdsc_put_request(req);
+ kfree(last_name);
+ dout("get_snap_name %p ino %llx.%llx err=%d\n",
+ child, ceph_vinop(inode), err);
+ return err;
+}
+
+static int ceph_get_name(struct dentry *parent, char *name,
+ struct dentry *child)
+{
+ struct ceph_mds_client *mdsc;
+ struct ceph_mds_request *req;
+ struct inode *inode = d_inode(child);
+ int err;
+
+ if (ceph_snap(inode) != CEPH_NOSNAP)
+ return __get_snap_name(parent, name, child);
+
+ mdsc = ceph_inode_to_client(inode)->mdsc;
+ req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
+ USE_ANY_MDS);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ inode_lock(d_inode(parent));
+
+ req->r_inode = inode;
+ ihold(inode);
+ req->r_ino2 = ceph_vino(d_inode(parent));
+ req->r_parent = d_inode(parent);
+ ihold(req->r_parent);
+ set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+ req->r_num_caps = 2;
+ err = ceph_mdsc_do_request(mdsc, NULL, req);
+
+ inode_unlock(d_inode(parent));
+
+ if (!err) {
+ struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
+ memcpy(name, rinfo->dname, rinfo->dname_len);
+ name[rinfo->dname_len] = 0;
+ dout("get_name %p ino %llx.%llx name %s\n",
+ child, ceph_vinop(inode), name);
+ } else {
+ dout("get_name %p ino %llx.%llx err %d\n",
+ child, ceph_vinop(inode), err);
+ }
+
+ ceph_mdsc_put_request(req);
+ return err;
+}
+
+const struct export_operations ceph_export_ops = {
+ .encode_fh = ceph_encode_fh,
+ .fh_to_dentry = ceph_fh_to_dentry,
+ .fh_to_parent = ceph_fh_to_parent,
+ .get_parent = ceph_get_parent,
+ .get_name = ceph_get_name,
+};