| Message ID | 20230906134711.4707-1-lhenriques@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ceph: add support for encrypted snapshot names | expand |
On 9/6/23 21:47, Luís Henriques wrote: > Since filenames in encrypted directories are encrypted and shown as > a base64-encoded string when the directory is locked, make snapshot > names show a similar behaviour. > > When creating a snapshot, .snap directories for every subdirectory will > show the snapshot name in the "long format": > > # mkdir .snap/my-snap > # ls my-dir/.snap/ > _my-snap_1099511627782 > > Encrypted snapshots will need to be able to handle these by > encrypting/decrypting only the snapshot part of the string ('my-snap'). > > Also, since the MDS prevents snapshot names to be bigger than 240 > characters it is necessary to adapt CEPH_NOHASH_NAME_MAX to accommodate > this extra limitation. > > [ idryomov: drop const on !CONFIG_FS_ENCRYPTION branch too ] > > Cc: Dan Carpenter <dan.carpenter@linaro.org> > Signed-off-by: Luís Henriques <lhenriques@suse.de> > Reviewed-by: Jeff Layton <jlayton@kernel.org> > Reviewed-by: Xiubo Li <xiubli@redhat.com> > Reviewed-by: Milind Changire <mchangir@redhat.com> > Signed-off-by: Ilya Dryomov <idryomov@gmail.com> > --- > As reported by Dan Carpenter, the initial version of this patch wasn't > dealing correctly with the ceph_get_inode() return value: it never returns > NULL. Simply dropped the code that handled the case where a NULL was > being returned. > > Xiubo, can you please pick this new revision, if you think it's correct? Hi Luis, Please generate a new patch to fix this, the fscrypt corresponding commits have been merged already. Thanks - Xiubo > And thanks, Dan! > > Cheers, > -- > Luís > > fs/ceph/crypto.c | 195 +++++++++++++++++++++++++++++++++++++++-------- > fs/ceph/crypto.h | 12 +-- > fs/ceph/inode.c | 33 +++++++- > 3 files changed, 199 insertions(+), 41 deletions(-) > > diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c > index 9494bf485f6a..7d0b9b5ccfc6 100644 > --- a/fs/ceph/crypto.c > +++ b/fs/ceph/crypto.c > @@ -193,17 +193,99 @@ void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, > swap(req->r_fscrypt_auth, as->fscrypt_auth); > } > > -int ceph_encode_encrypted_dname(const struct inode *parent, > - struct qstr *d_name, char *buf) > +/* > + * User-created snapshots can't start with '_'. Snapshots that start with this > + * character are special (hint: there aren't real snapshots) and use the > + * following format: > + * > + * _<SNAPSHOT-NAME>_<INODE-NUMBER> > + * > + * where: > + * - <SNAPSHOT-NAME> - the real snapshot name that may need to be decrypted, > + * - <INODE-NUMBER> - the inode number (in decimal) for the actual snapshot > + * > + * This function parses these snapshot names and returns the inode > + * <INODE-NUMBER>. 'name_len' will also bet set with the <SNAPSHOT-NAME> > + * length. > + */ > +static struct inode *parse_longname(const struct inode *parent, > + const char *name, int *name_len) > { > + struct inode *dir = NULL; > + struct ceph_vino vino = { .snap = CEPH_NOSNAP }; > + char *inode_number; > + char *name_end; > + int orig_len = *name_len; > + int ret = -EIO; > + > + /* Skip initial '_' */ > + name++; > + name_end = strrchr(name, '_'); > + if (!name_end) { > + dout("Failed to parse long snapshot name: %s\n", name); > + return ERR_PTR(-EIO); > + } > + *name_len = (name_end - name); > + if (*name_len <= 0) { > + pr_err("Failed to parse long snapshot name\n"); > + return ERR_PTR(-EIO); > + } > + > + /* Get the inode number */ > + inode_number = kmemdup_nul(name_end + 1, > + orig_len - *name_len - 2, > + GFP_KERNEL); > + if (!inode_number) > + return ERR_PTR(-ENOMEM); > + ret = kstrtou64(inode_number, 10, &vino.ino); > + if (ret) { > + dout("Failed to parse inode number: %s\n", name); > + dir = ERR_PTR(ret); > + goto out; > + } > + > + /* And finally the inode */ > + dir = ceph_find_inode(parent->i_sb, vino); > + if (!dir) { > + /* This can happen if we're not mounting cephfs on the root */ > + dir = ceph_get_inode(parent->i_sb, vino, NULL); > + } > + if (IS_ERR(dir)) > + dout("Can't find inode %s (%s)\n", inode_number, name); > + > +out: > + kfree(inode_number); > + return dir; > +} > + > +int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, > + char *buf) > +{ > + struct inode *dir = parent; > + struct qstr iname; > u32 len; > + int name_len; > int elen; > int ret; > - u8 *cryptbuf; > + u8 *cryptbuf = NULL; > + > + iname.name = d_name->name; > + name_len = d_name->len; > + > + /* Handle the special case of snapshot names that start with '_' */ > + if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) && > + (iname.name[0] == '_')) { > + dir = parse_longname(parent, iname.name, &name_len); > + if (IS_ERR(dir)) > + return PTR_ERR(dir); > + iname.name++; /* skip initial '_' */ > + } > + iname.len = name_len; > > - if (!fscrypt_has_encryption_key(parent)) { > + if (!fscrypt_has_encryption_key(dir)) { > memcpy(buf, d_name->name, d_name->len); > - return d_name->len; > + elen = d_name->len; > + goto out; > } > > /* > @@ -212,19 +294,23 @@ int ceph_encode_encrypted_dname(const struct inode *parent, > * > * See: fscrypt_setup_filename > */ > - if (!fscrypt_fname_encrypted_size(parent, d_name->len, NAME_MAX, &len)) > - return -ENAMETOOLONG; > + if (!fscrypt_fname_encrypted_size(dir, iname.len, NAME_MAX, &len)) { > + elen = -ENAMETOOLONG; > + goto out; > + } > > /* Allocate a buffer appropriate to hold the result */ > cryptbuf = kmalloc(len > CEPH_NOHASH_NAME_MAX ? NAME_MAX : len, > GFP_KERNEL); > - if (!cryptbuf) > - return -ENOMEM; > + if (!cryptbuf) { > + elen = -ENOMEM; > + goto out; > + } > > - ret = fscrypt_fname_encrypt(parent, d_name, cryptbuf, len); > + ret = fscrypt_fname_encrypt(dir, &iname, cryptbuf, len); > if (ret) { > - kfree(cryptbuf); > - return ret; > + elen = ret; > + goto out; > } > > /* hash the end if the name is long enough */ > @@ -243,13 +329,31 @@ int ceph_encode_encrypted_dname(const struct inode *parent, > > /* base64 encode the encrypted name */ > elen = ceph_base64_encode(cryptbuf, len, buf); > - kfree(cryptbuf); > dout("base64-encoded ciphertext name = %.*s\n", elen, buf); > + > + /* To understand the 240 limit, see CEPH_NOHASH_NAME_MAX comments */ > + WARN_ON(elen > 240); > + if ((elen > 0) && (dir != parent)) { > + char tmp_buf[NAME_MAX]; > + > + elen = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld", > + elen, buf, dir->i_ino); > + memcpy(buf, tmp_buf, elen); > + } > + > +out: > + kfree(cryptbuf); > + if (dir != parent) { > + if ((dir->i_state & I_NEW)) > + discard_new_inode(dir); > + else > + iput(dir); > + } > return elen; > } > > -int ceph_encode_encrypted_fname(const struct inode *parent, > - struct dentry *dentry, char *buf) > +int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, > + char *buf) > { > WARN_ON_ONCE(!fscrypt_has_encryption_key(parent)); > > @@ -274,29 +378,42 @@ int ceph_encode_encrypted_fname(const struct inode *parent, > int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, > struct fscrypt_str *oname, bool *is_nokey) > { > - int ret; > + struct inode *dir = fname->dir; > struct fscrypt_str _tname = FSTR_INIT(NULL, 0); > struct fscrypt_str iname; > - > - if (!IS_ENCRYPTED(fname->dir)) { > - oname->name = fname->name; > - oname->len = fname->name_len; > - return 0; > - } > + char *name = fname->name; > + int name_len = fname->name_len; > + int ret; > > /* Sanity check that the resulting name will fit in the buffer */ > if (fname->name_len > NAME_MAX || fname->ctext_len > NAME_MAX) > return -EIO; > > - ret = ceph_fscrypt_prepare_readdir(fname->dir); > - if (ret < 0) > - return ret; > + /* Handle the special case of snapshot names that start with '_' */ > + if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) && > + (name[0] == '_')) { > + dir = parse_longname(dir, name, &name_len); > + if (IS_ERR(dir)) > + return PTR_ERR(dir); > + name++; /* skip initial '_' */ > + } > + > + if (!IS_ENCRYPTED(dir)) { > + oname->name = fname->name; > + oname->len = fname->name_len; > + ret = 0; > + goto out_inode; > + } > + > + ret = ceph_fscrypt_prepare_readdir(dir); > + if (ret) > + goto out_inode; > > /* > * Use the raw dentry name as sent by the MDS instead of > * generating a nokey name via fscrypt. > */ > - if (!fscrypt_has_encryption_key(fname->dir)) { > + if (!fscrypt_has_encryption_key(dir)) { > if (fname->no_copy) > oname->name = fname->name; > else > @@ -304,7 +421,8 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, > oname->len = fname->name_len; > if (is_nokey) > *is_nokey = true; > - return 0; > + ret = 0; > + goto out_inode; > } > > if (fname->ctext_len == 0) { > @@ -313,12 +431,11 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, > if (!tname) { > ret = fscrypt_fname_alloc_buffer(NAME_MAX, &_tname); > if (ret) > - return ret; > + goto out_inode; > tname = &_tname; > } > > - declen = ceph_base64_decode(fname->name, fname->name_len, > - tname->name); > + declen = ceph_base64_decode(name, name_len, tname->name); > if (declen <= 0) { > ret = -EIO; > goto out; > @@ -330,9 +447,25 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, > iname.len = fname->ctext_len; > } > > - ret = fscrypt_fname_disk_to_usr(fname->dir, 0, 0, &iname, oname); > + ret = fscrypt_fname_disk_to_usr(dir, 0, 0, &iname, oname); > + if (!ret && (dir != fname->dir)) { > + char tmp_buf[CEPH_BASE64_CHARS(NAME_MAX)]; > + > + name_len = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld", > + oname->len, oname->name, dir->i_ino); > + memcpy(oname->name, tmp_buf, name_len); > + oname->len = name_len; > + } > + > out: > fscrypt_fname_free_buffer(&_tname); > +out_inode: > + if ((dir != fname->dir) && !IS_ERR(dir)) { > + if ((dir->i_state & I_NEW)) > + discard_new_inode(dir); > + else > + iput(dir); > + } > return ret; > } > > diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h > index 6afa6d888fe0..47e0c319fc68 100644 > --- a/fs/ceph/crypto.h > +++ b/fs/ceph/crypto.h > @@ -102,10 +102,10 @@ int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, > struct ceph_acl_sec_ctx *as); > void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, > struct ceph_acl_sec_ctx *as); > -int ceph_encode_encrypted_dname(const struct inode *parent, > - struct qstr *d_name, char *buf); > -int ceph_encode_encrypted_fname(const struct inode *parent, > - struct dentry *dentry, char *buf); > +int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, > + char *buf); > +int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, > + char *buf); > > static inline int ceph_fname_alloc_buffer(struct inode *parent, > struct fscrypt_str *fname) > @@ -194,14 +194,14 @@ static inline void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, > { > } > > -static inline int ceph_encode_encrypted_dname(const struct inode *parent, > +static inline int ceph_encode_encrypted_dname(struct inode *parent, > struct qstr *d_name, char *buf) > { > memcpy(buf, d_name->name, d_name->len); > return d_name->len; > } > > -static inline int ceph_encode_encrypted_fname(const struct inode *parent, > +static inline int ceph_encode_encrypted_fname(struct inode *parent, > struct dentry *dentry, char *buf) > { > return -EOPNOTSUPP; > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c > index 054fd66609b7..83c420646f90 100644 > --- a/fs/ceph/inode.c > +++ b/fs/ceph/inode.c > @@ -91,9 +91,15 @@ struct inode *ceph_new_inode(struct inode *dir, struct dentry *dentry, > if (err < 0) > goto out_err; > > - err = ceph_fscrypt_prepare_context(dir, inode, as_ctx); > - if (err) > - goto out_err; > + /* > + * We'll skip setting fscrypt context for snapshots, leaving that for > + * the handle_reply(). > + */ > + if (ceph_snap(dir) != CEPH_SNAPDIR) { > + err = ceph_fscrypt_prepare_context(dir, inode, as_ctx); > + if (err) > + goto out_err; > + } > > return inode; > out_err: > @@ -159,6 +165,7 @@ struct inode *ceph_get_snapdir(struct inode *parent) > }; > struct inode *inode = ceph_get_inode(parent->i_sb, vino, NULL); > struct ceph_inode_info *ci = ceph_inode(inode); > + int ret = -ENOTDIR; > > if (IS_ERR(inode)) > return inode; > @@ -184,6 +191,24 @@ struct inode *ceph_get_snapdir(struct inode *parent) > ci->i_rbytes = 0; > ci->i_btime = ceph_inode(parent)->i_btime; > > +#ifdef CONFIG_FS_ENCRYPTION > + /* if encrypted, just borrow fscrypt_auth from parent */ > + if (IS_ENCRYPTED(parent)) { > + struct ceph_inode_info *pci = ceph_inode(parent); > + > + ci->fscrypt_auth = kmemdup(pci->fscrypt_auth, > + pci->fscrypt_auth_len, > + GFP_KERNEL); > + if (ci->fscrypt_auth) { > + inode->i_flags |= S_ENCRYPTED; > + ci->fscrypt_auth_len = pci->fscrypt_auth_len; > + } else { > + dout("Failed to alloc snapdir fscrypt_auth\n"); > + ret = -ENOMEM; > + goto err; > + } > + } > +#endif > if (inode->i_state & I_NEW) { > inode->i_op = &ceph_snapdir_iops; > inode->i_fop = &ceph_snapdir_fops; > @@ -197,7 +222,7 @@ struct inode *ceph_get_snapdir(struct inode *parent) > discard_new_inode(inode); > else > iput(inode); > - return ERR_PTR(-ENOTDIR); > + return ERR_PTR(ret); > } > > const struct inode_operations ceph_file_iops = { >
Xiubo Li <xiubli@redhat.com> writes: > On 9/6/23 21:47, Luís Henriques wrote: >> Since filenames in encrypted directories are encrypted and shown as >> a base64-encoded string when the directory is locked, make snapshot >> names show a similar behaviour. >> >> When creating a snapshot, .snap directories for every subdirectory will >> show the snapshot name in the "long format": >> >> # mkdir .snap/my-snap >> # ls my-dir/.snap/ >> _my-snap_1099511627782 >> >> Encrypted snapshots will need to be able to handle these by >> encrypting/decrypting only the snapshot part of the string ('my-snap'). >> >> Also, since the MDS prevents snapshot names to be bigger than 240 >> characters it is necessary to adapt CEPH_NOHASH_NAME_MAX to accommodate >> this extra limitation. >> >> [ idryomov: drop const on !CONFIG_FS_ENCRYPTION branch too ] >> >> Cc: Dan Carpenter <dan.carpenter@linaro.org> >> Signed-off-by: Luís Henriques <lhenriques@suse.de> >> Reviewed-by: Jeff Layton <jlayton@kernel.org> >> Reviewed-by: Xiubo Li <xiubli@redhat.com> >> Reviewed-by: Milind Changire <mchangir@redhat.com> >> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> >> --- >> As reported by Dan Carpenter, the initial version of this patch wasn't >> dealing correctly with the ceph_get_inode() return value: it never returns >> NULL. Simply dropped the code that handled the case where a NULL was >> being returned. >> >> Xiubo, can you please pick this new revision, if you think it's correct? > > Hi Luis, > > Please generate a new patch to fix this, the fscrypt corresponding commits have > been merged already. Yeah, I just realised it was too late for it. Which is great, I'm glad it was too late, actually! :-) Anyway, I'll send out a separate fix for this, so that it can be included in -rc2. Cheers,
diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index 9494bf485f6a..7d0b9b5ccfc6 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -193,17 +193,99 @@ void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, swap(req->r_fscrypt_auth, as->fscrypt_auth); } -int ceph_encode_encrypted_dname(const struct inode *parent, - struct qstr *d_name, char *buf) +/* + * User-created snapshots can't start with '_'. Snapshots that start with this + * character are special (hint: there aren't real snapshots) and use the + * following format: + * + * _<SNAPSHOT-NAME>_<INODE-NUMBER> + * + * where: + * - <SNAPSHOT-NAME> - the real snapshot name that may need to be decrypted, + * - <INODE-NUMBER> - the inode number (in decimal) for the actual snapshot + * + * This function parses these snapshot names and returns the inode + * <INODE-NUMBER>. 'name_len' will also bet set with the <SNAPSHOT-NAME> + * length. + */ +static struct inode *parse_longname(const struct inode *parent, + const char *name, int *name_len) { + struct inode *dir = NULL; + struct ceph_vino vino = { .snap = CEPH_NOSNAP }; + char *inode_number; + char *name_end; + int orig_len = *name_len; + int ret = -EIO; + + /* Skip initial '_' */ + name++; + name_end = strrchr(name, '_'); + if (!name_end) { + dout("Failed to parse long snapshot name: %s\n", name); + return ERR_PTR(-EIO); + } + *name_len = (name_end - name); + if (*name_len <= 0) { + pr_err("Failed to parse long snapshot name\n"); + return ERR_PTR(-EIO); + } + + /* Get the inode number */ + inode_number = kmemdup_nul(name_end + 1, + orig_len - *name_len - 2, + GFP_KERNEL); + if (!inode_number) + return ERR_PTR(-ENOMEM); + ret = kstrtou64(inode_number, 10, &vino.ino); + if (ret) { + dout("Failed to parse inode number: %s\n", name); + dir = ERR_PTR(ret); + goto out; + } + + /* And finally the inode */ + dir = ceph_find_inode(parent->i_sb, vino); + if (!dir) { + /* This can happen if we're not mounting cephfs on the root */ + dir = ceph_get_inode(parent->i_sb, vino, NULL); + } + if (IS_ERR(dir)) + dout("Can't find inode %s (%s)\n", inode_number, name); + +out: + kfree(inode_number); + return dir; +} + +int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, + char *buf) +{ + struct inode *dir = parent; + struct qstr iname; u32 len; + int name_len; int elen; int ret; - u8 *cryptbuf; + u8 *cryptbuf = NULL; + + iname.name = d_name->name; + name_len = d_name->len; + + /* Handle the special case of snapshot names that start with '_' */ + if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) && + (iname.name[0] == '_')) { + dir = parse_longname(parent, iname.name, &name_len); + if (IS_ERR(dir)) + return PTR_ERR(dir); + iname.name++; /* skip initial '_' */ + } + iname.len = name_len; - if (!fscrypt_has_encryption_key(parent)) { + if (!fscrypt_has_encryption_key(dir)) { memcpy(buf, d_name->name, d_name->len); - return d_name->len; + elen = d_name->len; + goto out; } /* @@ -212,19 +294,23 @@ int ceph_encode_encrypted_dname(const struct inode *parent, * * See: fscrypt_setup_filename */ - if (!fscrypt_fname_encrypted_size(parent, d_name->len, NAME_MAX, &len)) - return -ENAMETOOLONG; + if (!fscrypt_fname_encrypted_size(dir, iname.len, NAME_MAX, &len)) { + elen = -ENAMETOOLONG; + goto out; + } /* Allocate a buffer appropriate to hold the result */ cryptbuf = kmalloc(len > CEPH_NOHASH_NAME_MAX ? NAME_MAX : len, GFP_KERNEL); - if (!cryptbuf) - return -ENOMEM; + if (!cryptbuf) { + elen = -ENOMEM; + goto out; + } - ret = fscrypt_fname_encrypt(parent, d_name, cryptbuf, len); + ret = fscrypt_fname_encrypt(dir, &iname, cryptbuf, len); if (ret) { - kfree(cryptbuf); - return ret; + elen = ret; + goto out; } /* hash the end if the name is long enough */ @@ -243,13 +329,31 @@ int ceph_encode_encrypted_dname(const struct inode *parent, /* base64 encode the encrypted name */ elen = ceph_base64_encode(cryptbuf, len, buf); - kfree(cryptbuf); dout("base64-encoded ciphertext name = %.*s\n", elen, buf); + + /* To understand the 240 limit, see CEPH_NOHASH_NAME_MAX comments */ + WARN_ON(elen > 240); + if ((elen > 0) && (dir != parent)) { + char tmp_buf[NAME_MAX]; + + elen = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld", + elen, buf, dir->i_ino); + memcpy(buf, tmp_buf, elen); + } + +out: + kfree(cryptbuf); + if (dir != parent) { + if ((dir->i_state & I_NEW)) + discard_new_inode(dir); + else + iput(dir); + } return elen; } -int ceph_encode_encrypted_fname(const struct inode *parent, - struct dentry *dentry, char *buf) +int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, + char *buf) { WARN_ON_ONCE(!fscrypt_has_encryption_key(parent)); @@ -274,29 +378,42 @@ int ceph_encode_encrypted_fname(const struct inode *parent, int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, struct fscrypt_str *oname, bool *is_nokey) { - int ret; + struct inode *dir = fname->dir; struct fscrypt_str _tname = FSTR_INIT(NULL, 0); struct fscrypt_str iname; - - if (!IS_ENCRYPTED(fname->dir)) { - oname->name = fname->name; - oname->len = fname->name_len; - return 0; - } + char *name = fname->name; + int name_len = fname->name_len; + int ret; /* Sanity check that the resulting name will fit in the buffer */ if (fname->name_len > NAME_MAX || fname->ctext_len > NAME_MAX) return -EIO; - ret = ceph_fscrypt_prepare_readdir(fname->dir); - if (ret < 0) - return ret; + /* Handle the special case of snapshot names that start with '_' */ + if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) && + (name[0] == '_')) { + dir = parse_longname(dir, name, &name_len); + if (IS_ERR(dir)) + return PTR_ERR(dir); + name++; /* skip initial '_' */ + } + + if (!IS_ENCRYPTED(dir)) { + oname->name = fname->name; + oname->len = fname->name_len; + ret = 0; + goto out_inode; + } + + ret = ceph_fscrypt_prepare_readdir(dir); + if (ret) + goto out_inode; /* * Use the raw dentry name as sent by the MDS instead of * generating a nokey name via fscrypt. */ - if (!fscrypt_has_encryption_key(fname->dir)) { + if (!fscrypt_has_encryption_key(dir)) { if (fname->no_copy) oname->name = fname->name; else @@ -304,7 +421,8 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, oname->len = fname->name_len; if (is_nokey) *is_nokey = true; - return 0; + ret = 0; + goto out_inode; } if (fname->ctext_len == 0) { @@ -313,12 +431,11 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, if (!tname) { ret = fscrypt_fname_alloc_buffer(NAME_MAX, &_tname); if (ret) - return ret; + goto out_inode; tname = &_tname; } - declen = ceph_base64_decode(fname->name, fname->name_len, - tname->name); + declen = ceph_base64_decode(name, name_len, tname->name); if (declen <= 0) { ret = -EIO; goto out; @@ -330,9 +447,25 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, iname.len = fname->ctext_len; } - ret = fscrypt_fname_disk_to_usr(fname->dir, 0, 0, &iname, oname); + ret = fscrypt_fname_disk_to_usr(dir, 0, 0, &iname, oname); + if (!ret && (dir != fname->dir)) { + char tmp_buf[CEPH_BASE64_CHARS(NAME_MAX)]; + + name_len = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld", + oname->len, oname->name, dir->i_ino); + memcpy(oname->name, tmp_buf, name_len); + oname->len = name_len; + } + out: fscrypt_fname_free_buffer(&_tname); +out_inode: + if ((dir != fname->dir) && !IS_ERR(dir)) { + if ((dir->i_state & I_NEW)) + discard_new_inode(dir); + else + iput(dir); + } return ret; } diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h index 6afa6d888fe0..47e0c319fc68 100644 --- a/fs/ceph/crypto.h +++ b/fs/ceph/crypto.h @@ -102,10 +102,10 @@ int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, struct ceph_acl_sec_ctx *as); void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as); -int ceph_encode_encrypted_dname(const struct inode *parent, - struct qstr *d_name, char *buf); -int ceph_encode_encrypted_fname(const struct inode *parent, - struct dentry *dentry, char *buf); +int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, + char *buf); +int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, + char *buf); static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) @@ -194,14 +194,14 @@ static inline void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, { } -static inline int ceph_encode_encrypted_dname(const struct inode *parent, +static inline int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, char *buf) { memcpy(buf, d_name->name, d_name->len); return d_name->len; } -static inline int ceph_encode_encrypted_fname(const struct inode *parent, +static inline int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, char *buf) { return -EOPNOTSUPP; diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 054fd66609b7..83c420646f90 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -91,9 +91,15 @@ struct inode *ceph_new_inode(struct inode *dir, struct dentry *dentry, if (err < 0) goto out_err; - err = ceph_fscrypt_prepare_context(dir, inode, as_ctx); - if (err) - goto out_err; + /* + * We'll skip setting fscrypt context for snapshots, leaving that for + * the handle_reply(). + */ + if (ceph_snap(dir) != CEPH_SNAPDIR) { + err = ceph_fscrypt_prepare_context(dir, inode, as_ctx); + if (err) + goto out_err; + } return inode; out_err: @@ -159,6 +165,7 @@ struct inode *ceph_get_snapdir(struct inode *parent) }; struct inode *inode = ceph_get_inode(parent->i_sb, vino, NULL); struct ceph_inode_info *ci = ceph_inode(inode); + int ret = -ENOTDIR; if (IS_ERR(inode)) return inode; @@ -184,6 +191,24 @@ struct inode *ceph_get_snapdir(struct inode *parent) ci->i_rbytes = 0; ci->i_btime = ceph_inode(parent)->i_btime; +#ifdef CONFIG_FS_ENCRYPTION + /* if encrypted, just borrow fscrypt_auth from parent */ + if (IS_ENCRYPTED(parent)) { + struct ceph_inode_info *pci = ceph_inode(parent); + + ci->fscrypt_auth = kmemdup(pci->fscrypt_auth, + pci->fscrypt_auth_len, + GFP_KERNEL); + if (ci->fscrypt_auth) { + inode->i_flags |= S_ENCRYPTED; + ci->fscrypt_auth_len = pci->fscrypt_auth_len; + } else { + dout("Failed to alloc snapdir fscrypt_auth\n"); + ret = -ENOMEM; + goto err; + } + } +#endif if (inode->i_state & I_NEW) { inode->i_op = &ceph_snapdir_iops; inode->i_fop = &ceph_snapdir_fops; @@ -197,7 +222,7 @@ struct inode *ceph_get_snapdir(struct inode *parent) discard_new_inode(inode); else iput(inode); - return ERR_PTR(-ENOTDIR); + return ERR_PTR(ret); } const struct inode_operations ceph_file_iops = {
Since filenames in encrypted directories are encrypted and shown as a base64-encoded string when the directory is locked, make snapshot names show a similar behaviour. When creating a snapshot, .snap directories for every subdirectory will show the snapshot name in the "long format": # mkdir .snap/my-snap # ls my-dir/.snap/ _my-snap_1099511627782 Encrypted snapshots will need to be able to handle these by encrypting/decrypting only the snapshot part of the string ('my-snap'). Also, since the MDS prevents snapshot names to be bigger than 240 characters it is necessary to adapt CEPH_NOHASH_NAME_MAX to accommodate this extra limitation. [ idryomov: drop const on !CONFIG_FS_ENCRYPTION branch too ] Cc: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Luís Henriques <lhenriques@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Milind Changire <mchangir@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> --- As reported by Dan Carpenter, the initial version of this patch wasn't dealing correctly with the ceph_get_inode() return value: it never returns NULL. Simply dropped the code that handled the case where a NULL was being returned. Xiubo, can you please pick this new revision, if you think it's correct? And thanks, Dan! Cheers, -- Luís fs/ceph/crypto.c | 195 +++++++++++++++++++++++++++++++++++++++-------- fs/ceph/crypto.h | 12 +-- fs/ceph/inode.c | 33 +++++++- 3 files changed, 199 insertions(+), 41 deletions(-)