ceph: add support to readdir for encrypted filenames

Add helper functions for buffer management and for decrypting filenames
returned by the MDS. Wire those into the readdir codepaths.

Signed-off-by: Jeff Layton <jlayton@kernel.org>

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 7977484d0317b1e9516ea6e098b8eacafd7812cb..f8812c976ba02c5abf2c4e973a0965b62b9b09ef 100644 (file)
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -9,6 +9,7 @@
 
 #include "super.h"
 #include "mds_client.h"
+#include "crypto.h"
 
 /*
  * Directory operations: readdir, lookup, create, link, unlink,
@@ -241,7 +242,9 @@ static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
                di = ceph_dentry(dentry);
                if (d_unhashed(dentry) ||
                    d_really_is_negative(dentry) ||
-                   di->lease_shared_gen != shared_gen) {
+                   di->lease_shared_gen != shared_gen ||
+                   ((dentry->d_flags & DCACHE_NOKEY_NAME) &&
+                    fscrypt_has_encryption_key(dir))) {
                        spin_unlock(&dentry->d_lock);
                        dput(dentry);
                        err = -EAGAIN;
@@ -313,6 +316,8 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
        int err;
        unsigned frag = -1;
        struct ceph_mds_reply_info_parsed *rinfo;
+       struct fscrypt_str tname = FSTR_INIT(NULL, 0);
+       struct fscrypt_str oname = FSTR_INIT(NULL, 0);
 
        dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
        if (dfi->file_info.flags & CEPH_F_ATEND)
@@ -340,6 +345,10 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
                ctx->pos = 2;
        }
 
+       err = fscrypt_prepare_readdir(inode);
+       if (err)
+               goto out;
+
        spin_lock(&ci->i_ceph_lock);
        /* request Fx cap. if have Fx, we don't need to release Fs cap
         * for later create/unlink. */
@@ -360,6 +369,14 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
                spin_unlock(&ci->i_ceph_lock);
        }
 
+       err = ceph_fname_alloc_buffer(inode, &tname);
+       if (err < 0)
+               goto out;
+
+       err = ceph_fname_alloc_buffer(inode, &oname);
+       if (err < 0)
+               goto out;
+
        /* proceed with a normal readdir */
 more:
        /* do we have the correct frag content buffered? */
@@ -387,12 +404,14 @@ more:
                dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
                     ceph_vinop(inode), frag, dfi->last_name);
                req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
-               if (IS_ERR(req))
-                       return PTR_ERR(req);
+               if (IS_ERR(req)) {
+                       err = PTR_ERR(req);
+                       goto out;
+               }
                err = ceph_alloc_readdir_reply_buffer(req, inode);
                if (err) {
                        ceph_mdsc_put_request(req);
-                       return err;
+                       goto out;
                }
                /* hints to request -> mds selection code */
                req->r_direct_mode = USE_AUTH_MDS;
@@ -405,7 +424,8 @@ more:
                        req->r_path2 = kstrdup(dfi->last_name, GFP_KERNEL);
                        if (!req->r_path2) {
                                ceph_mdsc_put_request(req);
-                               return -ENOMEM;
+                               err = -ENOMEM;
+                               goto out;
                        }
                } else if (is_hash_order(ctx->pos)) {
                        req->r_args.readdir.offset_hash =
@@ -426,7 +446,7 @@ more:
                err = ceph_mdsc_do_request(mdsc, NULL, req);
                if (err < 0) {
                        ceph_mdsc_put_request(req);
-                       return err;
+                       goto out;
                }
                dout("readdir got and parsed readdir result=%d on "
                     "frag %x, end=%d, complete=%d, hash_order=%d\n",
@@ -479,7 +499,7 @@ more:
                        err = note_last_dentry(dfi, rde->name, rde->name_len,
                                               next_offset);
                        if (err)
-                               return err;
+                               goto out;
                } else if (req->r_reply_info.dir_end) {
                        dfi->next_offset = 2;
                        /* keep last name */
@@ -507,22 +527,37 @@ more:
        }
        for (; i < rinfo->dir_nr; i++) {
                struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
+               struct ceph_fname fname = { .dir        = inode,
+                                           .name       = rde->name,
+                                           .name_len   = rde->name_len,
+                                           .ctext      = rde->altname,
+                                           .ctext_len  = rde->altname_len };
+               u32 olen = oname.len;
 
                BUG_ON(rde->offset < ctx->pos);
+               BUG_ON(!rde->inode.in);
 
                ctx->pos = rde->offset;
                dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
                     i, rinfo->dir_nr, ctx->pos,
                     rde->name_len, rde->name, &rde->inode.in);
 
-               BUG_ON(!rde->inode.in);
+               err = ceph_fname_to_usr(&fname, &tname, &oname, NULL);
+               if (err) {
+                       dout("Unable to decode %.*s. Skipping it.\n", rde->name_len, rde->name);
+                       continue;
+               }
 
-               if (!dir_emit(ctx, rde->name, rde->name_len,
+               if (!dir_emit(ctx, oname.name, oname.len,
                              ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
                              le32_to_cpu(rde->inode.in->mode) >> 12)) {
                        dout("filldir stopping us...\n");
-                       return 0;
+                       err = 0;
+                       goto out;
                }
+
+               /* Reset the lengths to their original allocated vals */
+               oname.len = olen;
                ctx->pos++;
        }
 
@@ -577,9 +612,12 @@ more:
                                        dfi->dir_ordered_count);
                spin_unlock(&ci->i_ceph_lock);
        }
-
+       err = 0;
        dout("readdir %p file %p done.\n", inode, file);
-       return 0;
+out:
+       ceph_fname_free_buffer(inode, &tname);
+       ceph_fname_free_buffer(inode, &oname);
+       return err;
 }
 
 static void reset_readdir(struct ceph_dir_file_info *dfi)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 6b2e639827ef6a17d5c2c2d1f332d90c435c9f1b..37cb0d334cf23f44e0b50c8f7d09773a9800b734 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1735,7 +1735,8 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
                             struct ceph_mds_session *session)
 {
        struct dentry *parent = req->r_dentry;
-       struct ceph_inode_info *ci = ceph_inode(d_inode(parent));
+       struct inode *inode = d_inode(parent);
+       struct ceph_inode_info *ci = ceph_inode(inode);
        struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
        struct qstr dname;
        struct dentry *dn;
@@ -1745,6 +1746,8 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
        u32 last_hash = 0;
        u32 fpos_offset;
        struct ceph_readdir_cache_control cache_ctl = {};
+       struct fscrypt_str tname = FSTR_INIT(NULL, 0);
+       struct fscrypt_str oname = FSTR_INIT(NULL, 0);
 
        if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
                return readdir_prepopulate_inodes_only(req, session);
@@ -1796,14 +1799,36 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
        cache_ctl.index = req->r_readdir_cache_idx;
        fpos_offset = req->r_readdir_offset;
 
+       err = ceph_fname_alloc_buffer(inode, &tname);
+       if (err < 0)
+               goto out;
+
+       err = ceph_fname_alloc_buffer(inode, &oname);
+       if (err < 0)
+               goto out;
+
        /* FIXME: release caps/leases if error occurs */
        for (i = 0; i < rinfo->dir_nr; i++) {
+               bool is_nokey = false;
                struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
                struct ceph_vino tvino;
+               u32 olen = oname.len;
+               struct ceph_fname fname = { .dir        = inode,
+                                           .name       = rde->name,
+                                           .name_len   = rde->name_len,
+                                           .ctext      = rde->altname,
+                                           .ctext_len  = rde->altname_len };
+
+               err = ceph_fname_to_usr(&fname, &tname, &oname, &is_nokey);
+               if (err) {
+                       dout("Unable to decode %.*s. Skipping it.", rde->name_len, rde->name);
+                       continue;
+               }
 
-               dname.name = rde->name;
-               dname.len = rde->name_len;
+               dname.name = oname.name;
+               dname.len = oname.len;
                dname.hash = full_name_hash(parent, dname.name, dname.len);
+               oname.len = olen;
 
                tvino.ino = le64_to_cpu(rde->inode.in->ino);
                tvino.snap = le64_to_cpu(rde->inode.in->snapid);
@@ -1834,6 +1859,11 @@ retry_lookup:
                                err = -ENOMEM;
                                goto out;
                        }
+                       if (is_nokey) {
+                               spin_lock(&dn->d_lock);
+                               dn->d_flags |= DCACHE_NOKEY_NAME;
+                               spin_unlock(&dn->d_lock);
+                       }
                } else if (d_really_is_positive(dn) &&
                           (ceph_ino(d_inode(dn)) != tvino.ino ||
                            ceph_snap(d_inode(dn)) != tvino.snap)) {
@@ -1922,6 +1952,8 @@ out:
                req->r_readdir_cache_idx = cache_ctl.index;
        }
        ceph_readdir_cache_release(&cache_ctl);
+       ceph_fname_free_buffer(inode, &tname);
+       ceph_fname_free_buffer(inode, &oname);
        dout("readdir_prepopulate done\n");
        return err;
 }