diff options
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/copy_up.c | 143 | ||||
| -rw-r--r-- | fs/overlayfs/dir.c | 587 | ||||
| -rw-r--r-- | fs/overlayfs/file.c | 97 | ||||
| -rw-r--r-- | fs/overlayfs/inode.c | 124 | ||||
| -rw-r--r-- | fs/overlayfs/namei.c | 402 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 63 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 110 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 138 | ||||
| -rw-r--r-- | fs/overlayfs/util.c | 43 | ||||
| -rw-r--r-- | fs/overlayfs/xattrs.c | 35 |
10 files changed, 843 insertions, 899 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 604a82acd164..758611ee4475 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -523,8 +523,8 @@ static int ovl_create_index(struct dentry *dentry, const struct ovl_fh *fh, { struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct dentry *indexdir = ovl_indexdir(dentry->d_sb); - struct dentry *index = NULL; struct dentry *temp = NULL; + struct renamedata rd = {}; struct qstr name = { }; int err; @@ -556,17 +556,15 @@ static int ovl_create_index(struct dentry *dentry, const struct ovl_fh *fh, if (err) goto out; - err = ovl_parent_lock(indexdir, temp); + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = indexdir; + rd.new_parent = indexdir; + err = start_renaming_dentry(&rd, 0, temp, &name); if (err) goto out; - index = ovl_lookup_upper(ofs, name.name, indexdir, name.len); - if (IS_ERR(index)) { - err = PTR_ERR(index); - } else { - err = ovl_do_rename(ofs, indexdir, temp, indexdir, index, 0); - dput(index); - } - ovl_parent_unlock(indexdir); + + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); out: if (err) ovl_cleanup(ofs, indexdir, temp); @@ -613,9 +611,9 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c) if (err) goto out; - inode_lock_nested(udir, I_MUTEX_PARENT); - upper = ovl_lookup_upper(ofs, c->dentry->d_name.name, upperdir, - c->dentry->d_name.len); + upper = ovl_start_creating_upper(ofs, upperdir, + &QSTR_LEN(c->dentry->d_name.name, + c->dentry->d_name.len)); err = PTR_ERR(upper); if (!IS_ERR(upper)) { err = ovl_do_link(ofs, ovl_dentry_upper(c->dentry), udir, upper); @@ -626,9 +624,8 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c) ovl_dentry_set_upper_alias(c->dentry); ovl_dentry_update_reval(c->dentry, upper); } - dput(upper); + end_creating(upper); } - inode_unlock(udir); if (err) goto out; @@ -727,34 +724,33 @@ static int ovl_copy_up_metadata(struct ovl_copy_up_ctx *c, struct dentry *temp) return err; } -struct ovl_cu_creds { - const struct cred *old; - struct cred *new; -}; - -static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) +static const struct cred *ovl_prepare_copy_up_creds(struct dentry *dentry) { + struct cred *copy_up_cred = NULL; int err; - cc->old = cc->new = NULL; - err = security_inode_copy_up(dentry, &cc->new); + err = security_inode_copy_up(dentry, ©_up_cred); if (err < 0) - return err; + return ERR_PTR(err); - if (cc->new) - cc->old = override_creds(cc->new); + if (!copy_up_cred) + return NULL; - return 0; + return override_creds(copy_up_cred); } -static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) +static void ovl_revert_copy_up_creds(const struct cred *orig_cred) { - if (cc->new) { - revert_creds(cc->old); - put_cred(cc->new); - } + const struct cred *copy_up_cred; + + copy_up_cred = revert_creds(orig_cred); + put_cred(copy_up_cred); } +DEFINE_CLASS(copy_up_creds, const struct cred *, + if (!IS_ERR_OR_NULL(_T)) ovl_revert_copy_up_creds(_T), + ovl_prepare_copy_up_creds(dentry), struct dentry *dentry) + /* * Copyup using workdir to prepare temp file. Used when copying up directories, * special files or when upper fs doesn't support O_TMPFILE. @@ -764,8 +760,8 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); struct inode *inode; struct path path = { .mnt = ovl_upper_mnt(ofs) }; - struct dentry *temp, *upper, *trap; - struct ovl_cu_creds cc; + struct renamedata rd = {}; + struct dentry *temp; int err; struct ovl_cattr cattr = { /* Can't properly set mode on creation because of the umask */ @@ -774,14 +770,14 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) .link = c->link }; - err = ovl_prep_cu_creds(c->dentry, &cc); - if (err) - return err; + scoped_class(copy_up_creds, copy_up_creds, c->dentry) { + if (IS_ERR(copy_up_creds)) + return PTR_ERR(copy_up_creds); - ovl_start_write(c->dentry); - temp = ovl_create_temp(ofs, c->workdir, &cattr); - ovl_end_write(c->dentry); - ovl_revert_cu_creds(&cc); + ovl_start_write(c->dentry); + temp = ovl_create_temp(ofs, c->workdir, &cattr); + ovl_end_write(c->dentry); + } if (IS_ERR(temp)) return PTR_ERR(temp); @@ -808,29 +804,24 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) * ovl_copy_up_data(), so lock workdir and destdir and make sure that * temp wasn't moved before copy up completion or cleanup. */ - trap = lock_rename(c->workdir, c->destdir); - if (trap || temp->d_parent != c->workdir) { - /* temp or workdir moved underneath us? abort without cleanup */ - dput(temp); + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = c->workdir; + rd.new_parent = c->destdir; + rd.flags = 0; + err = start_renaming_dentry(&rd, 0, temp, + &QSTR_LEN(c->destname.name, c->destname.len)); + if (err) { + /* temp or workdir moved underneath us? map to -EIO */ err = -EIO; - if (!IS_ERR(trap)) - unlock_rename(c->workdir, c->destdir); - goto out; } - - err = ovl_copy_up_metadata(c, temp); if (err) - goto cleanup; + goto cleanup_unlocked; - upper = ovl_lookup_upper(ofs, c->destname.name, c->destdir, - c->destname.len); - err = PTR_ERR(upper); - if (IS_ERR(upper)) - goto cleanup; + err = ovl_copy_up_metadata(c, temp); + if (!err) + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); - err = ovl_do_rename(ofs, c->workdir, temp, c->destdir, upper, 0); - unlock_rename(c->workdir, c->destdir); - dput(upper); if (err) goto cleanup_unlocked; @@ -851,8 +842,6 @@ out: return err; -cleanup: - unlock_rename(c->workdir, c->destdir); cleanup_unlocked: ovl_cleanup(ofs, c->workdir, temp); dput(temp); @@ -866,17 +855,17 @@ static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) struct inode *udir = d_inode(c->destdir); struct dentry *temp, *upper; struct file *tmpfile; - struct ovl_cu_creds cc; int err; - err = ovl_prep_cu_creds(c->dentry, &cc); - if (err) - return err; + scoped_class(copy_up_creds, copy_up_creds, c->dentry) { + if (IS_ERR(copy_up_creds)) + return PTR_ERR(copy_up_creds); + + ovl_start_write(c->dentry); + tmpfile = ovl_do_tmpfile(ofs, c->workdir, c->stat.mode); + ovl_end_write(c->dentry); + } - ovl_start_write(c->dentry); - tmpfile = ovl_do_tmpfile(ofs, c->workdir, c->stat.mode); - ovl_end_write(c->dentry); - ovl_revert_cu_creds(&cc); if (IS_ERR(tmpfile)) return PTR_ERR(tmpfile); @@ -894,16 +883,14 @@ static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) if (err) goto out; - inode_lock_nested(udir, I_MUTEX_PARENT); - - upper = ovl_lookup_upper(ofs, c->destname.name, c->destdir, - c->destname.len); + upper = ovl_start_creating_upper(ofs, c->destdir, + &QSTR_LEN(c->destname.name, + c->destname.len)); err = PTR_ERR(upper); if (!IS_ERR(upper)) { err = ovl_do_link(ofs, temp, udir, upper); - dput(upper); + end_creating(upper); } - inode_unlock(udir); if (err) goto out; @@ -1214,7 +1201,6 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, static int ovl_copy_up_flags(struct dentry *dentry, int flags) { int err = 0; - const struct cred *old_cred; bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); /* @@ -1234,7 +1220,6 @@ static int ovl_copy_up_flags(struct dentry *dentry, int flags) if (err) return err; - old_cred = ovl_override_creds(dentry->d_sb); while (!err) { struct dentry *next; struct dentry *parent = NULL; @@ -1254,12 +1239,12 @@ static int ovl_copy_up_flags(struct dentry *dentry, int flags) next = parent; } - err = ovl_copy_up_one(parent, next, flags); + with_ovl_creds(dentry->d_sb) + err = ovl_copy_up_one(parent, next, flags); dput(parent); dput(next); } - ovl_revert_creds(old_cred); return err; } diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index a5e9ddf3023b..06b860b9ded6 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -47,79 +47,70 @@ static int ovl_cleanup_locked(struct ovl_fs *ofs, struct inode *wdir, int ovl_cleanup(struct ovl_fs *ofs, struct dentry *workdir, struct dentry *wdentry) { - int err; - - err = ovl_parent_lock(workdir, wdentry); - if (err) - return err; + wdentry = start_removing_dentry(workdir, wdentry); + if (IS_ERR(wdentry)) + return PTR_ERR(wdentry); ovl_cleanup_locked(ofs, workdir->d_inode, wdentry); - ovl_parent_unlock(workdir); + end_removing(wdentry); return 0; } -struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir) +void ovl_tempname(char name[OVL_TEMPNAME_SIZE]) { - struct dentry *temp; - char name[20]; static atomic_t temp_id = ATOMIC_INIT(0); /* counter is allowed to wrap, since temp dentries are ephemeral */ - snprintf(name, sizeof(name), "#%x", atomic_inc_return(&temp_id)); + snprintf(name, OVL_TEMPNAME_SIZE, "#%x", atomic_inc_return(&temp_id)); +} - temp = ovl_lookup_upper(ofs, name, workdir, strlen(name)); - if (!IS_ERR(temp) && temp->d_inode) { - pr_err("workdir/%s already exists\n", name); - dput(temp); - temp = ERR_PTR(-EIO); - } +static struct dentry *ovl_start_creating_temp(struct ovl_fs *ofs, + struct dentry *workdir) +{ + char name[OVL_TEMPNAME_SIZE]; - return temp; + ovl_tempname(name); + return start_creating(ovl_upper_mnt_idmap(ofs), workdir, + &QSTR(name)); } static struct dentry *ovl_whiteout(struct ovl_fs *ofs) { int err; - struct dentry *whiteout; + struct dentry *whiteout, *link; struct dentry *workdir = ofs->workdir; struct inode *wdir = workdir->d_inode; guard(mutex)(&ofs->whiteout_lock); if (!ofs->whiteout) { - inode_lock_nested(wdir, I_MUTEX_PARENT); - whiteout = ovl_lookup_temp(ofs, workdir); - if (!IS_ERR(whiteout)) { - err = ovl_do_whiteout(ofs, wdir, whiteout); - if (err) { - dput(whiteout); - whiteout = ERR_PTR(err); - } - } - inode_unlock(wdir); + whiteout = ovl_start_creating_temp(ofs, workdir); if (IS_ERR(whiteout)) return whiteout; - ofs->whiteout = whiteout; + err = ovl_do_whiteout(ofs, wdir, whiteout); + if (!err) + ofs->whiteout = dget(whiteout); + end_creating(whiteout); + if (err) + return ERR_PTR(err); } if (!ofs->no_shared_whiteout) { - inode_lock_nested(wdir, I_MUTEX_PARENT); - whiteout = ovl_lookup_temp(ofs, workdir); - if (!IS_ERR(whiteout)) { - err = ovl_do_link(ofs, ofs->whiteout, wdir, whiteout); - if (err) { - dput(whiteout); - whiteout = ERR_PTR(err); - } - } - inode_unlock(wdir); - if (!IS_ERR(whiteout)) + link = ovl_start_creating_temp(ofs, workdir); + if (IS_ERR(link)) + return link; + err = ovl_do_link(ofs, ofs->whiteout, wdir, link); + if (!err) + whiteout = dget(link); + end_creating(link); + if (!err) return whiteout; - if (PTR_ERR(whiteout) != -EMLINK) { - pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%lu)\n", + + if (err != -EMLINK) { + pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%u)\n", ofs->whiteout->d_inode->i_nlink, - PTR_ERR(whiteout)); + err); ofs->no_shared_whiteout = true; } } @@ -132,6 +123,7 @@ int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct dentry *dir, struct dentry *dentry) { struct dentry *whiteout; + struct renamedata rd = {}; int err; int flags = 0; @@ -143,10 +135,14 @@ int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct dentry *dir, if (d_is_dir(dentry)) flags = RENAME_EXCHANGE; - err = ovl_lock_rename_workdir(ofs->workdir, whiteout, dir, dentry); + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = ofs->workdir; + rd.new_parent = dir; + rd.flags = flags; + err = start_renaming_two_dentries(&rd, whiteout, dentry); if (!err) { - err = ovl_do_rename(ofs, ofs->workdir, whiteout, dir, dentry, flags); - unlock_rename(ofs->workdir, dir); + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); } if (err) goto kill_whiteout; @@ -191,7 +187,7 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct dentry *parent, if (!err && ofs->casefold != ovl_dentry_casefolded(newdentry)) { pr_warn_ratelimited("wrong inherited casefold (%pd2)\n", newdentry); - dput(newdentry); + end_creating(newdentry); err = -EINVAL; } break; @@ -241,8 +237,7 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct dentry *parent, } out: if (err) { - if (!IS_ERR(newdentry)) - dput(newdentry); + end_creating(newdentry); return ERR_PTR(err); } return newdentry; @@ -252,11 +247,11 @@ struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, struct ovl_cattr *attr) { struct dentry *ret; - inode_lock_nested(workdir->d_inode, I_MUTEX_PARENT); - ret = ovl_create_real(ofs, workdir, - ovl_lookup_temp(ofs, workdir), attr); - inode_unlock(workdir->d_inode); - return ret; + ret = ovl_start_creating_temp(ofs, workdir); + if (IS_ERR(ret)) + return ret; + ret = ovl_create_real(ofs, workdir, ret, attr); + return end_creating_keep(ret); } static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper, @@ -354,18 +349,19 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, { struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); - struct inode *udir = upperdir->d_inode; struct dentry *newdentry; int err; - inode_lock_nested(udir, I_MUTEX_PARENT); - newdentry = ovl_create_real(ofs, upperdir, - ovl_lookup_upper(ofs, dentry->d_name.name, - upperdir, dentry->d_name.len), - attr); - inode_unlock(udir); + newdentry = ovl_start_creating_upper(ofs, upperdir, + &QSTR_LEN(dentry->d_name.name, + dentry->d_name.len)); if (IS_ERR(newdentry)) return PTR_ERR(newdentry); + newdentry = ovl_create_real(ofs, upperdir, newdentry, attr); + if (IS_ERR(newdentry)) + return PTR_ERR(newdentry); + + end_creating_keep(newdentry); if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry) && !ovl_allow_offline_changes(ofs)) { @@ -391,6 +387,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct dentry *workdir = ovl_workdir(dentry); struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); + struct renamedata rd = {}; struct path upperpath; struct dentry *upper; struct dentry *opaquedir; @@ -416,7 +413,11 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, if (IS_ERR(opaquedir)) goto out; - err = ovl_lock_rename_workdir(workdir, opaquedir, upperdir, upper); + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = workdir; + rd.new_parent = upperdir; + rd.flags = RENAME_EXCHANGE; + err = start_renaming_two_dentries(&rd, opaquedir, upper); if (err) goto out_cleanup_unlocked; @@ -434,8 +435,8 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, if (err) goto out_cleanup; - err = ovl_do_rename(ofs, workdir, opaquedir, upperdir, upper, RENAME_EXCHANGE); - unlock_rename(workdir, upperdir); + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); if (err) goto out_cleanup_unlocked; @@ -448,7 +449,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, return opaquedir; out_cleanup: - unlock_rename(workdir, upperdir); + end_renaming(&rd); out_cleanup_unlocked: ovl_cleanup(ofs, workdir, opaquedir); dput(opaquedir); @@ -471,6 +472,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct dentry *workdir = ovl_workdir(dentry); struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); + struct renamedata rd = {}; struct dentry *upper; struct dentry *newdentry; int err; @@ -502,7 +504,11 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, if (IS_ERR(newdentry)) goto out_dput; - err = ovl_lock_rename_workdir(workdir, newdentry, upperdir, upper); + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = workdir; + rd.new_parent = upperdir; + rd.flags = 0; + err = start_renaming_two_dentries(&rd, newdentry, upper); if (err) goto out_cleanup_unlocked; @@ -539,16 +545,16 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, if (err) goto out_cleanup; - err = ovl_do_rename(ofs, workdir, newdentry, upperdir, upper, - RENAME_EXCHANGE); - unlock_rename(workdir, upperdir); + rd.flags = RENAME_EXCHANGE; + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); if (err) goto out_cleanup_unlocked; ovl_cleanup(ofs, workdir, upper); } else { - err = ovl_do_rename(ofs, workdir, newdentry, upperdir, upper, 0); - unlock_rename(workdir, upperdir); + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); if (err) goto out_cleanup_unlocked; } @@ -568,66 +574,76 @@ out: return err; out_cleanup: - unlock_rename(workdir, upperdir); + end_renaming(&rd); out_cleanup_unlocked: ovl_cleanup(ofs, workdir, newdentry); dput(newdentry); goto out_dput; } -static const struct cred *ovl_setup_cred_for_create(struct dentry *dentry, - struct inode *inode, - umode_t mode, - const struct cred *old_cred) +static const struct cred *ovl_override_creator_creds(struct dentry *dentry, struct inode *inode, umode_t mode) { int err; - struct cred *override_cred; - override_cred = prepare_creds(); + if (WARN_ON_ONCE(current->cred != ovl_creds(dentry->d_sb))) + return ERR_PTR(-EINVAL); + + CLASS(prepare_creds, override_cred)(); if (!override_cred) return ERR_PTR(-ENOMEM); override_cred->fsuid = inode->i_uid; override_cred->fsgid = inode->i_gid; + err = security_dentry_create_files_as(dentry, mode, &dentry->d_name, - old_cred, override_cred); - if (err) { - put_cred(override_cred); + current->cred, override_cred); + if (err) return ERR_PTR(err); - } - /* - * Caller is going to match this with revert_creds() and drop - * referenec on the returned creds. - * We must be called with creator creds already, otherwise we risk - * leaking creds. - */ - old_cred = override_creds(override_cred); - WARN_ON_ONCE(old_cred != ovl_creds(dentry->d_sb)); + return override_creds(no_free_ptr(override_cred)); +} + +static void ovl_revert_creator_creds(const struct cred *old_cred) +{ + const struct cred *override_cred; - return override_cred; + override_cred = revert_creds(old_cred); + put_cred(override_cred); +} + +DEFINE_CLASS(ovl_override_creator_creds, + const struct cred *, + if (!IS_ERR_OR_NULL(_T)) ovl_revert_creator_creds(_T), + ovl_override_creator_creds(dentry, inode, mode), + struct dentry *dentry, struct inode *inode, umode_t mode) + +static int ovl_create_handle_whiteouts(struct dentry *dentry, + struct inode *inode, + struct ovl_cattr *attr) +{ + if (!ovl_dentry_is_whiteout(dentry)) + return ovl_create_upper(dentry, inode, attr); + + return ovl_create_over_whiteout(dentry, inode, attr); } static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, struct ovl_cattr *attr, bool origin) { int err; - const struct cred *old_cred, *new_cred = NULL; struct dentry *parent = dentry->d_parent; - old_cred = ovl_override_creds(dentry->d_sb); - - /* - * When linking a file with copy up origin into a new parent, mark the - * new parent dir "impure". - */ - if (origin) { - err = ovl_set_impure(parent, ovl_dentry_upper(parent)); - if (err) - goto out_revert_creds; - } + with_ovl_creds(dentry->d_sb) { + /* + * When linking a file with copy up origin into a new parent, mark the + * new parent dir "impure". + */ + if (origin) { + err = ovl_set_impure(parent, ovl_dentry_upper(parent)); + if (err) + return err; + } - if (!attr->hardlink) { /* * In the creation cases(create, mkdir, mknod, symlink), * ovl should transfer current's fs{u,g}id to underlying @@ -641,23 +657,16 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, * create a new inode, so just use the ovl mounter's * fs{u,g}id. */ - new_cred = ovl_setup_cred_for_create(dentry, inode, attr->mode, - old_cred); - err = PTR_ERR(new_cred); - if (IS_ERR(new_cred)) { - new_cred = NULL; - goto out_revert_creds; - } - } - if (!ovl_dentry_is_whiteout(dentry)) - err = ovl_create_upper(dentry, inode, attr); - else - err = ovl_create_over_whiteout(dentry, inode, attr); + if (attr->hardlink) + return ovl_create_handle_whiteouts(dentry, inode, attr); -out_revert_creds: - ovl_revert_creds(old_cred); - put_cred(new_cred); + scoped_class(ovl_override_creator_creds, cred, dentry, inode, attr->mode) { + if (IS_ERR(cred)) + return PTR_ERR(cred); + return ovl_create_handle_whiteouts(dentry, inode, attr); + } + } return err; } @@ -686,7 +695,7 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, goto out_drop_write; spin_lock(&inode->i_lock); - inode->i_state |= I_CREATING; + inode_state_set(inode, I_CREATING); spin_unlock(&inode->i_lock); inode_init_owner(&nop_mnt_idmap, inode, dentry->d_parent->d_inode, mode); @@ -733,14 +742,8 @@ static int ovl_symlink(struct mnt_idmap *idmap, struct inode *dir, static int ovl_set_link_redirect(struct dentry *dentry) { - const struct cred *old_cred; - int err; - - old_cred = ovl_override_creds(dentry->d_sb); - err = ovl_set_redirect(dentry, false); - ovl_revert_creds(old_cred); - - return err; + with_ovl_creds(dentry->d_sb) + return ovl_set_redirect(dentry, false); } static int ovl_link(struct dentry *old, struct inode *newdir, @@ -850,17 +853,17 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir, goto out; } - inode_lock_nested(dir, I_MUTEX_PARENT); - upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir, - dentry->d_name.len); + upper = ovl_start_removing_upper(ofs, upperdir, + &QSTR_LEN(dentry->d_name.name, + dentry->d_name.len)); err = PTR_ERR(upper); if (IS_ERR(upper)) - goto out_unlock; + goto out_dput; err = -ESTALE; if ((opaquedir && upper != opaquedir) || (!opaquedir && !ovl_matches_upper(dentry, upper))) - goto out_dput_upper; + goto out_unlock; if (is_dir) err = ovl_do_rmdir(ofs, dir, upper); @@ -876,10 +879,9 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir, */ if (!err) d_drop(dentry); -out_dput_upper: - dput(upper); out_unlock: - inode_unlock(dir); + end_removing(upper); +out_dput: dput(opaquedir); out: return err; @@ -916,7 +918,6 @@ static void ovl_drop_nlink(struct dentry *dentry) static int ovl_do_remove(struct dentry *dentry, bool is_dir) { int err; - const struct cred *old_cred; bool lower_positive = ovl_lower_positive(dentry); LIST_HEAD(list); @@ -935,12 +936,12 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir) if (err) goto out; - old_cred = ovl_override_creds(dentry->d_sb); - if (!lower_positive) - err = ovl_remove_upper(dentry, is_dir, &list); - else - err = ovl_remove_and_whiteout(dentry, &list); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) { + if (!lower_positive) + err = ovl_remove_upper(dentry, is_dir, &list); + else + err = ovl_remove_and_whiteout(dentry, &list); + } if (!err) { if (is_dir) clear_nlink(dentry->d_inode); @@ -1104,102 +1105,107 @@ static int ovl_set_redirect(struct dentry *dentry, bool samedir) return err; } -static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, - struct dentry *old, struct inode *newdir, - struct dentry *new, unsigned int flags) +struct ovl_renamedata { + struct renamedata; + struct dentry *opaquedir; + bool cleanup_whiteout; + bool update_nlink; + bool overwrite; +}; + +static int ovl_rename_start(struct ovl_renamedata *ovlrd, struct list_head *list) { - int err; - struct dentry *old_upperdir; - struct dentry *new_upperdir; - struct dentry *olddentry = NULL; - struct dentry *newdentry = NULL; - struct dentry *trap, *de; - bool old_opaque; - bool new_opaque; - bool cleanup_whiteout = false; - bool update_nlink = false; - bool overwrite = !(flags & RENAME_EXCHANGE); + struct dentry *old = ovlrd->old_dentry; + struct dentry *new = ovlrd->new_dentry; bool is_dir = d_is_dir(old); bool new_is_dir = d_is_dir(new); - bool samedir = olddir == newdir; - struct dentry *opaquedir = NULL; - const struct cred *old_cred = NULL; - struct ovl_fs *ofs = OVL_FS(old->d_sb); - LIST_HEAD(list); + int err; - err = -EINVAL; - if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) - goto out; + if (ovlrd->flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) + return -EINVAL; - flags &= ~RENAME_NOREPLACE; + ovlrd->flags &= ~RENAME_NOREPLACE; /* Don't copy up directory trees */ err = -EXDEV; if (!ovl_can_move(old)) - goto out; - if (!overwrite && !ovl_can_move(new)) - goto out; + return err; + if (!ovlrd->overwrite && !ovl_can_move(new)) + return err; - if (overwrite && new_is_dir && !ovl_pure_upper(new)) { - err = ovl_check_empty_dir(new, &list); + if (ovlrd->overwrite && new_is_dir && !ovl_pure_upper(new)) { + err = ovl_check_empty_dir(new, list); if (err) - goto out; + return err; } - if (overwrite) { + if (ovlrd->overwrite) { if (ovl_lower_positive(old)) { if (!ovl_dentry_is_whiteout(new)) { /* Whiteout source */ - flags |= RENAME_WHITEOUT; + ovlrd->flags |= RENAME_WHITEOUT; } else { /* Switch whiteouts */ - flags |= RENAME_EXCHANGE; + ovlrd->flags |= RENAME_EXCHANGE; } } else if (is_dir && ovl_dentry_is_whiteout(new)) { - flags |= RENAME_EXCHANGE; - cleanup_whiteout = true; + ovlrd->flags |= RENAME_EXCHANGE; + ovlrd->cleanup_whiteout = true; } } err = ovl_copy_up(old); if (err) - goto out; + return err; err = ovl_copy_up(new->d_parent); if (err) - goto out; - if (!overwrite) { + return err; + + if (!ovlrd->overwrite) { err = ovl_copy_up(new); if (err) - goto out; + return err; } else if (d_inode(new)) { err = ovl_nlink_start(new); if (err) - goto out; + return err; - update_nlink = true; + ovlrd->update_nlink = true; } - if (!update_nlink) { + if (!ovlrd->update_nlink) { /* ovl_nlink_start() took ovl_want_write() */ err = ovl_want_write(old); if (err) - goto out; + return err; } - old_cred = ovl_override_creds(old->d_sb); + return 0; +} - if (!list_empty(&list)) { - opaquedir = ovl_clear_empty(new, &list); - err = PTR_ERR(opaquedir); - if (IS_ERR(opaquedir)) { - opaquedir = NULL; - goto out_revert_creds; - } - } +static int ovl_rename_upper(struct ovl_renamedata *ovlrd, struct list_head *list) +{ + struct dentry *old = ovlrd->old_dentry; + struct dentry *new = ovlrd->new_dentry; + struct ovl_fs *ofs = OVL_FS(old->d_sb); + struct dentry *old_upperdir = ovl_dentry_upper(old->d_parent); + struct dentry *new_upperdir = ovl_dentry_upper(new->d_parent); + bool is_dir = d_is_dir(old); + bool new_is_dir = d_is_dir(new); + bool samedir = old->d_parent == new->d_parent; + struct renamedata rd = {}; + struct dentry *de; + struct dentry *whiteout = NULL; + bool old_opaque, new_opaque; + int err; - old_upperdir = ovl_dentry_upper(old->d_parent); - new_upperdir = ovl_dentry_upper(new->d_parent); + if (!list_empty(list)) { + de = ovl_clear_empty(new, list); + if (IS_ERR(de)) + return PTR_ERR(de); + ovlrd->opaquedir = de; + } if (!samedir) { /* @@ -1211,95 +1217,88 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, if (ovl_type_origin(old)) { err = ovl_set_impure(new->d_parent, new_upperdir); if (err) - goto out_revert_creds; + return err; } - if (!overwrite && ovl_type_origin(new)) { + if (!ovlrd->overwrite && ovl_type_origin(new)) { err = ovl_set_impure(old->d_parent, old_upperdir); if (err) - goto out_revert_creds; + return err; } } - trap = lock_rename(new_upperdir, old_upperdir); - if (IS_ERR(trap)) { - err = PTR_ERR(trap); - goto out_revert_creds; - } + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = old_upperdir; + rd.new_parent = new_upperdir; + rd.flags = ovlrd->flags; - de = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir, - old->d_name.len); - err = PTR_ERR(de); - if (IS_ERR(de)) - goto out_unlock; - olddentry = de; + err = start_renaming(&rd, 0, + &QSTR_LEN(old->d_name.name, old->d_name.len), + &QSTR_LEN(new->d_name.name, new->d_name.len)); + if (err) + return err; err = -ESTALE; - if (!ovl_matches_upper(old, olddentry)) + if (!ovl_matches_upper(old, rd.old_dentry)) goto out_unlock; - de = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir, - new->d_name.len); - err = PTR_ERR(de); - if (IS_ERR(de)) - goto out_unlock; - newdentry = de; - old_opaque = ovl_dentry_is_opaque(old); new_opaque = ovl_dentry_is_opaque(new); err = -ESTALE; if (d_inode(new) && ovl_dentry_upper(new)) { - if (opaquedir) { - if (newdentry != opaquedir) + if (ovlrd->opaquedir) { + if (rd.new_dentry != ovlrd->opaquedir) goto out_unlock; } else { - if (!ovl_matches_upper(new, newdentry)) + if (!ovl_matches_upper(new, rd.new_dentry)) goto out_unlock; } } else { - if (!d_is_negative(newdentry)) { - if (!new_opaque || !ovl_upper_is_whiteout(ofs, newdentry)) + if (!d_is_negative(rd.new_dentry)) { + if (!new_opaque || !ovl_upper_is_whiteout(ofs, rd.new_dentry)) goto out_unlock; } else { - if (flags & RENAME_EXCHANGE) + if (ovlrd->flags & RENAME_EXCHANGE) goto out_unlock; } } - if (olddentry == trap) - goto out_unlock; - if (newdentry == trap) - goto out_unlock; - - if (olddentry->d_inode == newdentry->d_inode) + if (rd.old_dentry->d_inode == rd.new_dentry->d_inode) goto out_unlock; err = 0; if (ovl_type_merge_or_lower(old)) err = ovl_set_redirect(old, samedir); else if (is_dir && !old_opaque && ovl_type_merge(new->d_parent)) - err = ovl_set_opaque_xerr(old, olddentry, -EXDEV); + err = ovl_set_opaque_xerr(old, rd.old_dentry, -EXDEV); if (err) goto out_unlock; - if (!overwrite && ovl_type_merge_or_lower(new)) + if (!ovlrd->overwrite && ovl_type_merge_or_lower(new)) err = ovl_set_redirect(new, samedir); - else if (!overwrite && new_is_dir && !new_opaque && + else if (!ovlrd->overwrite && new_is_dir && !new_opaque && ovl_type_merge(old->d_parent)) - err = ovl_set_opaque_xerr(new, newdentry, -EXDEV); + err = ovl_set_opaque_xerr(new, rd.new_dentry, -EXDEV); if (err) goto out_unlock; - err = ovl_do_rename(ofs, old_upperdir, olddentry, - new_upperdir, newdentry, flags); - unlock_rename(new_upperdir, old_upperdir); + err = ovl_do_rename_rd(&rd); + + if (!err && ovlrd->cleanup_whiteout) + whiteout = dget(rd.new_dentry); + +out_unlock: + end_renaming(&rd); + if (err) - goto out_revert_creds; + return err; - if (cleanup_whiteout) - ovl_cleanup(ofs, old_upperdir, newdentry); + if (whiteout) { + ovl_cleanup(ofs, old_upperdir, whiteout); + dput(whiteout); + } - if (overwrite && d_inode(new)) { + if (ovlrd->overwrite && d_inode(new)) { if (new_is_dir) clear_nlink(d_inode(new)); else @@ -1307,7 +1306,7 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, } ovl_dir_modified(old->d_parent, ovl_type_origin(old) || - (!overwrite && ovl_type_origin(new))); + (!ovlrd->overwrite && ovl_type_origin(new))); ovl_dir_modified(new->d_parent, ovl_type_origin(old) || (d_inode(new) && ovl_type_origin(new))); @@ -1316,28 +1315,47 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, if (d_inode(new) && ovl_dentry_upper(new)) ovl_copyattr(d_inode(new)); -out_revert_creds: - ovl_revert_creds(old_cred); - if (update_nlink) - ovl_nlink_end(new); + return err; +} + +static void ovl_rename_end(struct ovl_renamedata *ovlrd) +{ + if (ovlrd->update_nlink) + ovl_nlink_end(ovlrd->new_dentry); else - ovl_drop_write(old); -out: - dput(newdentry); - dput(olddentry); - dput(opaquedir); + ovl_drop_write(ovlrd->old_dentry); +} + +static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, + struct dentry *old, struct inode *newdir, + struct dentry *new, unsigned int flags) +{ + struct ovl_renamedata ovlrd = { + .old_parent = old->d_parent, + .old_dentry = old, + .new_parent = new->d_parent, + .new_dentry = new, + .flags = flags, + .overwrite = !(flags & RENAME_EXCHANGE), + }; + LIST_HEAD(list); + int err; + + err = ovl_rename_start(&ovlrd, &list); + if (!err) { + with_ovl_creds(old->d_sb) + err = ovl_rename_upper(&ovlrd, &list); + ovl_rename_end(&ovlrd); + } + + dput(ovlrd.opaquedir); ovl_cache_free(&list); return err; - -out_unlock: - unlock_rename(new_upperdir, old_upperdir); - goto out_revert_creds; } static int ovl_create_tmpfile(struct file *file, struct dentry *dentry, struct inode *inode, umode_t mode) { - const struct cred *old_cred, *new_cred = NULL; struct path realparentpath; struct file *realfile; struct ovl_file *of; @@ -1346,41 +1364,36 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry, int flags = file->f_flags | OVL_OPEN_FLAGS; int err; - old_cred = ovl_override_creds(dentry->d_sb); - new_cred = ovl_setup_cred_for_create(dentry, inode, mode, old_cred); - err = PTR_ERR(new_cred); - if (IS_ERR(new_cred)) { - new_cred = NULL; - goto out_revert_creds; - } + with_ovl_creds(dentry->d_sb) { + scoped_class(ovl_override_creator_creds, cred, dentry, inode, mode) { + if (IS_ERR(cred)) + return PTR_ERR(cred); - ovl_path_upper(dentry->d_parent, &realparentpath); - realfile = backing_tmpfile_open(&file->f_path, flags, &realparentpath, - mode, current_cred()); - err = PTR_ERR_OR_ZERO(realfile); - pr_debug("tmpfile/open(%pd2, 0%o) = %i\n", realparentpath.dentry, mode, err); - if (err) - goto out_revert_creds; + ovl_path_upper(dentry->d_parent, &realparentpath); + realfile = backing_tmpfile_open(&file->f_path, flags, &realparentpath, + mode, current_cred()); + err = PTR_ERR_OR_ZERO(realfile); + pr_debug("tmpfile/open(%pd2, 0%o) = %i\n", realparentpath.dentry, mode, err); + if (err) + return err; - of = ovl_file_alloc(realfile); - if (!of) { - fput(realfile); - err = -ENOMEM; - goto out_revert_creds; - } + of = ovl_file_alloc(realfile); + if (!of) { + fput(realfile); + return -ENOMEM; + } - /* ovl_instantiate() consumes the newdentry reference on success */ - newdentry = dget(realfile->f_path.dentry); - err = ovl_instantiate(dentry, inode, newdentry, false, file); - if (!err) { - file->private_data = of; - } else { - dput(newdentry); - ovl_file_free(of); + /* ovl_instantiate() consumes the newdentry reference on success */ + newdentry = dget(realfile->f_path.dentry); + err = ovl_instantiate(dentry, inode, newdentry, false, file); + if (!err) { + file->private_data = of; + } else { + dput(newdentry); + ovl_file_free(of); + } + } } -out_revert_creds: - ovl_revert_creds(old_cred); - put_cred(new_cred); return err; } diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 7ab2c9daffd0..cbae89457234 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -31,7 +31,6 @@ static struct file *ovl_open_realfile(const struct file *file, struct inode *inode = file_inode(file); struct mnt_idmap *real_idmap; struct file *realfile; - const struct cred *old_cred; int flags = file->f_flags | OVL_OPEN_FLAGS; int acc_mode = ACC_MODE(flags); int err; @@ -39,19 +38,19 @@ static struct file *ovl_open_realfile(const struct file *file, if (flags & O_APPEND) acc_mode |= MAY_APPEND; - old_cred = ovl_override_creds(inode->i_sb); - real_idmap = mnt_idmap(realpath->mnt); - err = inode_permission(real_idmap, realinode, MAY_OPEN | acc_mode); - if (err) { - realfile = ERR_PTR(err); - } else { - if (!inode_owner_or_capable(real_idmap, realinode)) - flags &= ~O_NOATIME; - - realfile = backing_file_open(file_user_path(file), - flags, realpath, current_cred()); + with_ovl_creds(inode->i_sb) { + real_idmap = mnt_idmap(realpath->mnt); + err = inode_permission(real_idmap, realinode, MAY_OPEN | acc_mode); + if (err) { + realfile = ERR_PTR(err); + } else { + if (!inode_owner_or_capable(real_idmap, realinode)) + flags &= ~O_NOATIME; + + realfile = backing_file_open(file_user_path(file), + flags, realpath, current_cred()); + } } - ovl_revert_creds(old_cred); pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n", file, file, ovl_whatisit(inode, realinode), file->f_flags, @@ -244,7 +243,6 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) { struct inode *inode = file_inode(file); struct file *realfile; - const struct cred *old_cred; loff_t ret; /* @@ -273,9 +271,8 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) ovl_inode_lock(inode); realfile->f_pos = file->f_pos; - old_cred = ovl_override_creds(inode->i_sb); - ret = vfs_llseek(realfile, offset, whence); - ovl_revert_creds(old_cred); + with_ovl_creds(inode->i_sb) + ret = vfs_llseek(realfile, offset, whence); file->f_pos = realfile->f_pos; ovl_inode_unlock(inode); @@ -447,7 +444,6 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) enum ovl_path_type type; struct path upperpath; struct file *upperfile; - const struct cred *old_cred; int ret; ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb)); @@ -464,11 +460,8 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) if (IS_ERR(upperfile)) return PTR_ERR(upperfile); - old_cred = ovl_override_creds(file_inode(file)->i_sb); - ret = vfs_fsync_range(upperfile, start, end, datasync); - ovl_revert_creds(old_cred); - - return ret; + with_ovl_creds(file_inode(file)->i_sb) + return vfs_fsync_range(upperfile, start, end, datasync); } static int ovl_mmap(struct file *file, struct vm_area_struct *vma) @@ -486,7 +479,6 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len { struct inode *inode = file_inode(file); struct file *realfile; - const struct cred *old_cred; int ret; inode_lock(inode); @@ -501,9 +493,8 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len if (IS_ERR(realfile)) goto out_unlock; - old_cred = ovl_override_creds(file_inode(file)->i_sb); - ret = vfs_fallocate(realfile, mode, offset, len); - ovl_revert_creds(old_cred); + with_ovl_creds(inode->i_sb) + ret = vfs_fallocate(realfile, mode, offset, len); /* Update size */ ovl_file_modified(file); @@ -517,18 +508,13 @@ out_unlock: static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice) { struct file *realfile; - const struct cred *old_cred; - int ret; realfile = ovl_real_file(file); if (IS_ERR(realfile)) return PTR_ERR(realfile); - old_cred = ovl_override_creds(file_inode(file)->i_sb); - ret = vfs_fadvise(realfile, offset, len, advice); - ovl_revert_creds(old_cred); - - return ret; + with_ovl_creds(file_inode(file)->i_sb) + return vfs_fadvise(realfile, offset, len, advice); } enum ovl_copyop { @@ -543,7 +529,6 @@ static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in, { struct inode *inode_out = file_inode(file_out); struct file *realfile_in, *realfile_out; - const struct cred *old_cred; loff_t ret; inode_lock(inode_out); @@ -565,25 +550,25 @@ static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in, if (IS_ERR(realfile_in)) goto out_unlock; - old_cred = ovl_override_creds(file_inode(file_out)->i_sb); - switch (op) { - case OVL_COPY: - ret = vfs_copy_file_range(realfile_in, pos_in, - realfile_out, pos_out, len, flags); - break; - - case OVL_CLONE: - ret = vfs_clone_file_range(realfile_in, pos_in, - realfile_out, pos_out, len, flags); - break; - - case OVL_DEDUPE: - ret = vfs_dedupe_file_range_one(realfile_in, pos_in, - realfile_out, pos_out, len, - flags); - break; + with_ovl_creds(file_inode(file_out)->i_sb) { + switch (op) { + case OVL_COPY: + ret = vfs_copy_file_range(realfile_in, pos_in, + realfile_out, pos_out, len, flags); + break; + + case OVL_CLONE: + ret = vfs_clone_file_range(realfile_in, pos_in, + realfile_out, pos_out, len, flags); + break; + + case OVL_DEDUPE: + ret = vfs_dedupe_file_range_one(realfile_in, pos_in, + realfile_out, pos_out, len, + flags); + break; + } } - ovl_revert_creds(old_cred); /* Update size */ ovl_file_modified(file_out); @@ -632,7 +617,6 @@ static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in, static int ovl_flush(struct file *file, fl_owner_t id) { struct file *realfile; - const struct cred *old_cred; int err = 0; realfile = ovl_real_file(file); @@ -640,9 +624,8 @@ static int ovl_flush(struct file *file, fl_owner_t id) return PTR_ERR(realfile); if (realfile->f_op->flush) { - old_cred = ovl_override_creds(file_inode(file)->i_sb); - err = realfile->f_op->flush(realfile, id); - ovl_revert_creds(old_cred); + with_ovl_creds(file_inode(file)->i_sb) + err = realfile->f_op->flush(realfile, id); } return err; diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index e11f310ce092..bdbf86b56a9b 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -25,7 +25,6 @@ int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct ovl_fs *ofs = OVL_FS(dentry->d_sb); bool full_copy_up = false; struct dentry *upperdentry; - const struct cred *old_cred; err = setattr_prepare(&nop_mnt_idmap, dentry, attr); if (err) @@ -78,9 +77,8 @@ int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, goto out_put_write; inode_lock(upperdentry->d_inode); - old_cred = ovl_override_creds(dentry->d_sb); - err = ovl_do_notify_change(ofs, upperdentry, attr); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + err = ovl_do_notify_change(ofs, upperdentry, attr); if (!err) ovl_copyattr(dentry->d_inode); inode_unlock(upperdentry->d_inode); @@ -153,13 +151,22 @@ static void ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid) } } +static inline int ovl_real_getattr_nosec(struct super_block *sb, + const struct path *path, + struct kstat *stat, u32 request_mask, + unsigned int flags) +{ + with_ovl_creds(sb) + return vfs_getattr_nosec(path, stat, request_mask, flags); +} + int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags) { struct dentry *dentry = path->dentry; + struct super_block *sb = dentry->d_sb; enum ovl_path_type type; struct path realpath; - const struct cred *old_cred; struct inode *inode = d_inode(dentry); bool is_dir = S_ISDIR(inode->i_mode); int fsid = 0; @@ -169,10 +176,9 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, metacopy_blocks = ovl_is_metacopy_dentry(dentry); type = ovl_path_real(dentry, &realpath); - old_cred = ovl_override_creds(dentry->d_sb); - err = vfs_getattr_nosec(&realpath, stat, request_mask, flags); + err = ovl_real_getattr_nosec(sb, &realpath, stat, request_mask, flags); if (err) - goto out; + return err; /* Report the effective immutable/append-only STATX flags */ generic_fill_statx_attr(inode, stat); @@ -195,10 +201,9 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, (!is_dir ? STATX_NLINK : 0); ovl_path_lower(dentry, &realpath); - err = vfs_getattr_nosec(&realpath, &lowerstat, lowermask, - flags); + err = ovl_real_getattr_nosec(sb, &realpath, &lowerstat, lowermask, flags); if (err) - goto out; + return err; /* * Lower hardlinks may be broken on copy up to different @@ -248,10 +253,10 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, ovl_path_lowerdata(dentry, &realpath); if (realpath.dentry) { - err = vfs_getattr_nosec(&realpath, &lowerdatastat, - lowermask, flags); + err = ovl_real_getattr_nosec(sb, &realpath, &lowerdatastat, + lowermask, flags); if (err) - goto out; + return err; } else { lowerdatastat.blocks = round_up(stat->size, stat->blksize) >> 9; @@ -279,9 +284,6 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, if (!is_dir && ovl_test_flag(OVL_INDEX, d_inode(dentry))) stat->nlink = dentry->d_inode->i_nlink; -out: - ovl_revert_creds(old_cred); - return err; } @@ -291,7 +293,6 @@ int ovl_permission(struct mnt_idmap *idmap, struct inode *upperinode = ovl_inode_upper(inode); struct inode *realinode; struct path realpath; - const struct cred *old_cred; int err; /* Careful in RCU walk mode */ @@ -309,33 +310,26 @@ int ovl_permission(struct mnt_idmap *idmap, if (err) return err; - old_cred = ovl_override_creds(inode->i_sb); if (!upperinode && !special_file(realinode->i_mode) && mask & MAY_WRITE) { mask &= ~(MAY_WRITE | MAY_APPEND); /* Make sure mounter can read file for copy up later */ mask |= MAY_READ; } - err = inode_permission(mnt_idmap(realpath.mnt), realinode, mask); - ovl_revert_creds(old_cred); - return err; + with_ovl_creds(inode->i_sb) + return inode_permission(mnt_idmap(realpath.mnt), realinode, mask); } static const char *ovl_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { - const struct cred *old_cred; - const char *p; - if (!dentry) return ERR_PTR(-ECHILD); - old_cred = ovl_override_creds(dentry->d_sb); - p = vfs_get_link(ovl_dentry_real(dentry), done); - ovl_revert_creds(old_cred); - return p; + with_ovl_creds(dentry->d_sb) + return vfs_get_link(ovl_dentry_real(dentry), done); } #ifdef CONFIG_FS_POSIX_ACL @@ -465,11 +459,8 @@ struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, acl = get_cached_acl_rcu(realinode, type); } else { - const struct cred *old_cred; - - old_cred = ovl_override_creds(inode->i_sb); - acl = ovl_get_acl_path(&realpath, posix_acl_xattr_name(type), noperm); - ovl_revert_creds(old_cred); + with_ovl_creds(inode->i_sb) + acl = ovl_get_acl_path(&realpath, posix_acl_xattr_name(type), noperm); } return acl; @@ -481,7 +472,6 @@ static int ovl_set_or_remove_acl(struct dentry *dentry, struct inode *inode, int err; struct path realpath; const char *acl_name; - const struct cred *old_cred; struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct dentry *upperdentry = ovl_dentry_upper(dentry); struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry); @@ -495,10 +485,8 @@ static int ovl_set_or_remove_acl(struct dentry *dentry, struct inode *inode, struct posix_acl *real_acl; ovl_path_lower(dentry, &realpath); - old_cred = ovl_override_creds(dentry->d_sb); - real_acl = vfs_get_acl(mnt_idmap(realpath.mnt), realdentry, - acl_name); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + real_acl = vfs_get_acl(mnt_idmap(realpath.mnt), realdentry, acl_name); if (IS_ERR(real_acl)) { err = PTR_ERR(real_acl); goto out; @@ -518,12 +506,12 @@ static int ovl_set_or_remove_acl(struct dentry *dentry, struct inode *inode, if (err) goto out; - old_cred = ovl_override_creds(dentry->d_sb); - if (acl) - err = ovl_do_set_acl(ofs, realdentry, acl_name, acl); - else - err = ovl_do_remove_acl(ofs, realdentry, acl_name); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) { + if (acl) + err = ovl_do_set_acl(ofs, realdentry, acl_name, acl); + else + err = ovl_do_remove_acl(ofs, realdentry, acl_name); + } ovl_drop_write(dentry); /* copy c/mtime */ @@ -588,9 +576,7 @@ int ovl_update_time(struct inode *inode, int flags) static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) { - int err; struct inode *realinode = ovl_inode_realdata(inode); - const struct cred *old_cred; if (!realinode) return -EIO; @@ -598,11 +584,8 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, if (!realinode->i_op->fiemap) return -EOPNOTSUPP; - old_cred = ovl_override_creds(inode->i_sb); - err = realinode->i_op->fiemap(realinode, fieinfo, start, len); - ovl_revert_creds(old_cred); - - return err; + with_ovl_creds(inode->i_sb) + return realinode->i_op->fiemap(realinode, fieinfo, start, len); } /* @@ -653,7 +636,6 @@ int ovl_fileattr_set(struct mnt_idmap *idmap, { struct inode *inode = d_inode(dentry); struct path upperpath; - const struct cred *old_cred; unsigned int flags; int err; @@ -665,18 +647,18 @@ int ovl_fileattr_set(struct mnt_idmap *idmap, if (err) goto out; - old_cred = ovl_override_creds(inode->i_sb); - /* - * Store immutable/append-only flags in xattr and clear them - * in upper fileattr (in case they were set by older kernel) - * so children of "ovl-immutable" directories lower aliases of - * "ovl-immutable" hardlinks could be copied up. - * Clear xattr when flags are cleared. - */ - err = ovl_set_protattr(inode, upperpath.dentry, fa); - if (!err) - err = ovl_real_fileattr_set(&upperpath, fa); - ovl_revert_creds(old_cred); + with_ovl_creds(inode->i_sb) { + /* + * Store immutable/append-only flags in xattr and clear them + * in upper fileattr (in case they were set by older kernel) + * so children of "ovl-immutable" directories lower aliases of + * "ovl-immutable" hardlinks could be copied up. + * Clear xattr when flags are cleared. + */ + err = ovl_set_protattr(inode, upperpath.dentry, fa); + if (!err) + err = ovl_real_fileattr_set(&upperpath, fa); + } ovl_drop_write(dentry); /* @@ -730,15 +712,13 @@ int ovl_fileattr_get(struct dentry *dentry, struct file_kattr *fa) { struct inode *inode = d_inode(dentry); struct path realpath; - const struct cred *old_cred; int err; ovl_path_real(dentry, &realpath); - old_cred = ovl_override_creds(inode->i_sb); - err = ovl_real_fileattr_get(&realpath, fa); + with_ovl_creds(inode->i_sb) + err = ovl_real_fileattr_get(&realpath, fa); ovl_fileattr_prot_flags(inode, fa); - ovl_revert_creds(old_cred); return err; } @@ -1152,7 +1132,7 @@ struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir) if (!trap) return ERR_PTR(-ENOMEM); - if (!(trap->i_state & I_NEW)) { + if (!(inode_state_read_once(trap) & I_NEW)) { /* Conflicting layer roots? */ iput(trap); return ERR_PTR(-ELOOP); @@ -1243,7 +1223,7 @@ struct inode *ovl_get_inode(struct super_block *sb, inode = ovl_iget5(sb, oip->newinode, key); if (!inode) goto out_err; - if (!(inode->i_state & I_NEW)) { + if (!(inode_state_read_once(inode) & I_NEW)) { /* * Verify that the underlying files stored in the inode * match those in the dentry. @@ -1303,7 +1283,7 @@ struct inode *ovl_get_inode(struct super_block *sb, if (upperdentry) ovl_check_protattr(inode, upperdentry); - if (inode->i_state & I_NEW) + if (inode_state_read_once(inode) & I_NEW) unlock_new_inode(inode); out: return inode; diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index e93bcc5727bc..e9a69c95be91 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -979,15 +979,10 @@ static int ovl_maybe_validate_verity(struct dentry *dentry) return err; if (!ovl_test_flag(OVL_VERIFIED_DIGEST, inode)) { - const struct cred *old_cred; - - old_cred = ovl_override_creds(dentry->d_sb); - - err = ovl_validate_verity(ofs, &metapath, &datapath); + with_ovl_creds(dentry->d_sb) + err = ovl_validate_verity(ofs, &metapath, &datapath); if (err == 0) ovl_set_flag(OVL_VERIFIED_DIGEST, inode); - - ovl_revert_creds(old_cred); } ovl_inode_unlock(inode); @@ -1001,7 +996,6 @@ static int ovl_maybe_lookup_lowerdata(struct dentry *dentry) struct inode *inode = d_inode(dentry); const char *redirect = ovl_lowerdata_redirect(inode); struct ovl_path datapath = {}; - const struct cred *old_cred; int err; if (!redirect || ovl_dentry_lowerdata(dentry)) @@ -1019,9 +1013,8 @@ static int ovl_maybe_lookup_lowerdata(struct dentry *dentry) if (ovl_dentry_lowerdata(dentry)) goto out; - old_cred = ovl_override_creds(dentry->d_sb); - err = ovl_lookup_data_layers(dentry, redirect, &datapath); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + err = ovl_lookup_data_layers(dentry, redirect, &datapath); if (err) goto out_err; @@ -1077,57 +1070,44 @@ static bool ovl_check_follow_redirect(struct ovl_lookup_data *d) return true; } -struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, - unsigned int flags) +struct ovl_lookup_ctx { + struct dentry *dentry; + struct ovl_entry *oe; + struct ovl_path *stack; + struct ovl_path *origin_path; + struct dentry *upperdentry; + struct dentry *index; + struct inode *inode; + unsigned int ctr; +}; + +static int ovl_lookup_layers(struct ovl_lookup_ctx *ctx, struct ovl_lookup_data *d) { - struct ovl_entry *oe = NULL; - const struct cred *old_cred; + struct dentry *dentry = ctx->dentry; struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct ovl_entry *poe = OVL_E(dentry->d_parent); struct ovl_entry *roe = OVL_E(dentry->d_sb->s_root); - struct ovl_path *stack = NULL, *origin_path = NULL; - struct dentry *upperdir, *upperdentry = NULL; - struct dentry *origin = NULL; - struct dentry *index = NULL; - unsigned int ctr = 0; - struct inode *inode = NULL; - bool upperopaque = false; bool check_redirect = (ovl_redirect_follow(ofs) || ofs->numdatalayer); + struct dentry *upperdir; struct dentry *this; - unsigned int i; - int err; + struct dentry *origin = NULL; + bool upperopaque = false; bool uppermetacopy = false; int metacopy_size = 0; - struct ovl_lookup_data d = { - .sb = dentry->d_sb, - .dentry = dentry, - .name = dentry->d_name, - .is_dir = false, - .opaque = false, - .stop = false, - .last = check_redirect ? false : !ovl_numlower(poe), - .redirect = NULL, - .upperredirect = NULL, - .metacopy = 0, - }; - - if (dentry->d_name.len > ofs->namelen) - return ERR_PTR(-ENAMETOOLONG); + unsigned int i; + int err; - old_cred = ovl_override_creds(dentry->d_sb); upperdir = ovl_dentry_upper(dentry->d_parent); if (upperdir) { - d.layer = &ofs->layers[0]; - err = ovl_lookup_layer(upperdir, &d, &upperdentry, true); + d->layer = &ofs->layers[0]; + err = ovl_lookup_layer(upperdir, d, &ctx->upperdentry, true); if (err) - goto out; + return err; - if (upperdentry && upperdentry->d_flags & DCACHE_OP_REAL) { - dput(upperdentry); - err = -EREMOTE; - goto out; - } - if (upperdentry && !d.is_dir) { + if (ctx->upperdentry && ctx->upperdentry->d_flags & DCACHE_OP_REAL) + return -EREMOTE; + + if (ctx->upperdentry && !d->is_dir) { /* * Lookup copy up origin by decoding origin file handle. * We may get a disconnected dentry, which is fine, @@ -1138,50 +1118,50 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * number - it's the same as if we held a reference * to a dentry in lower layer that was moved under us. */ - err = ovl_check_origin(ofs, upperdentry, &origin_path); + err = ovl_check_origin(ofs, ctx->upperdentry, &ctx->origin_path); if (err) - goto out_put_upper; + return err; - if (d.metacopy) + if (d->metacopy) uppermetacopy = true; - metacopy_size = d.metacopy; + metacopy_size = d->metacopy; } - if (d.redirect) { + if (d->redirect) { err = -ENOMEM; - d.upperredirect = kstrdup(d.redirect, GFP_KERNEL); - if (!d.upperredirect) - goto out_put_upper; - if (d.redirect[0] == '/') + d->upperredirect = kstrdup(d->redirect, GFP_KERNEL); + if (!d->upperredirect) + return err; + if (d->redirect[0] == '/') poe = roe; } - upperopaque = d.opaque; + upperopaque = d->opaque; } - if (!d.stop && ovl_numlower(poe)) { + if (!d->stop && ovl_numlower(poe)) { err = -ENOMEM; - stack = ovl_stack_alloc(ofs->numlayer - 1); - if (!stack) - goto out_put_upper; + ctx->stack = ovl_stack_alloc(ofs->numlayer - 1); + if (!ctx->stack) + return err; } - for (i = 0; !d.stop && i < ovl_numlower(poe); i++) { + for (i = 0; !d->stop && i < ovl_numlower(poe); i++) { struct ovl_path lower = ovl_lowerstack(poe)[i]; - if (!ovl_check_follow_redirect(&d)) { + if (!ovl_check_follow_redirect(d)) { err = -EPERM; - goto out_put; + return err; } if (!check_redirect) - d.last = i == ovl_numlower(poe) - 1; - else if (d.is_dir || !ofs->numdatalayer) - d.last = lower.layer->idx == ovl_numlower(roe); + d->last = i == ovl_numlower(poe) - 1; + else if (d->is_dir || !ofs->numdatalayer) + d->last = lower.layer->idx == ovl_numlower(roe); - d.layer = lower.layer; - err = ovl_lookup_layer(lower.dentry, &d, &this, false); + d->layer = lower.layer; + err = ovl_lookup_layer(lower.dentry, d, &this, false); if (err) - goto out_put; + return err; if (!this) continue; @@ -1190,11 +1170,11 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * If no origin fh is stored in upper of a merge dir, store fh * of lower dir and set upper parent "impure". */ - if (upperdentry && !ctr && !ofs->noxattr && d.is_dir) { - err = ovl_fix_origin(ofs, dentry, this, upperdentry); + if (ctx->upperdentry && !ctx->ctr && !ofs->noxattr && d->is_dir) { + err = ovl_fix_origin(ofs, dentry, this, ctx->upperdentry); if (err) { dput(this); - goto out_put; + return err; } } @@ -1207,23 +1187,23 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * matches the dentry found using path based lookup, * otherwise error out. */ - if (upperdentry && !ctr && - ((d.is_dir && ovl_verify_lower(dentry->d_sb)) || - (!d.is_dir && ofs->config.index && origin_path))) { - err = ovl_verify_origin(ofs, upperdentry, this, false); + if (ctx->upperdentry && !ctx->ctr && + ((d->is_dir && ovl_verify_lower(dentry->d_sb)) || + (!d->is_dir && ofs->config.index && ctx->origin_path))) { + err = ovl_verify_origin(ofs, ctx->upperdentry, this, false); if (err) { dput(this); - if (d.is_dir) + if (d->is_dir) break; - goto out_put; + return err; } origin = this; } - if (!upperdentry && !d.is_dir && !ctr && d.metacopy) - metacopy_size = d.metacopy; + if (!ctx->upperdentry && !d->is_dir && !ctx->ctr && d->metacopy) + metacopy_size = d->metacopy; - if (d.metacopy && ctr) { + if (d->metacopy && ctx->ctr) { /* * Do not store intermediate metacopy dentries in * lower chain, except top most lower metacopy dentry. @@ -1233,15 +1213,15 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, dput(this); this = NULL; } else { - stack[ctr].dentry = this; - stack[ctr].layer = lower.layer; - ctr++; + ctx->stack[ctx->ctr].dentry = this; + ctx->stack[ctx->ctr].layer = lower.layer; + ctx->ctr++; } - if (d.stop) + if (d->stop) break; - if (d.redirect && d.redirect[0] == '/' && poe != roe) { + if (d->redirect && d->redirect[0] == '/' && poe != roe) { poe = roe; /* Find the current layer on the root dentry */ i = lower.layer->idx - 1; @@ -1252,12 +1232,12 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * Defer lookup of lowerdata in data-only layers to first access. * Don't require redirect=follow and metacopy=on in this case. */ - if (d.metacopy && ctr && ofs->numdatalayer && d.absolute_redirect) { - d.metacopy = 0; - ctr++; - } else if (!ovl_check_follow_redirect(&d)) { + if (d->metacopy && ctx->ctr && ofs->numdatalayer && d->absolute_redirect) { + d->metacopy = 0; + ctx->ctr++; + } else if (!ovl_check_follow_redirect(d)) { err = -EPERM; - goto out_put; + return err; } /* @@ -1268,20 +1248,20 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * For metacopy dentry, path based lookup will find lower dentries. * Just make sure a corresponding data dentry has been found. */ - if (d.metacopy || (uppermetacopy && !ctr)) { + if (d->metacopy || (uppermetacopy && !ctx->ctr)) { pr_warn_ratelimited("metacopy with no lower data found - abort lookup (%pd2)\n", dentry); err = -EIO; - goto out_put; - } else if (!d.is_dir && upperdentry && !ctr && origin_path) { - if (WARN_ON(stack != NULL)) { + return err; + } else if (!d->is_dir && ctx->upperdentry && !ctx->ctr && ctx->origin_path) { + if (WARN_ON(ctx->stack != NULL)) { err = -EIO; - goto out_put; + return err; } - stack = origin_path; - ctr = 1; - origin = origin_path->dentry; - origin_path = NULL; + ctx->stack = ctx->origin_path; + ctx->ctr = 1; + origin = ctx->origin_path->dentry; + ctx->origin_path = NULL; } /* @@ -1303,38 +1283,39 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * is enabled and if upper had an ORIGIN xattr. * */ - if (!upperdentry && ctr) - origin = stack[0].dentry; + if (!ctx->upperdentry && ctx->ctr) + origin = ctx->stack[0].dentry; if (origin && ovl_indexdir(dentry->d_sb) && - (!d.is_dir || ovl_index_all(dentry->d_sb))) { - index = ovl_lookup_index(ofs, upperdentry, origin, true); - if (IS_ERR(index)) { - err = PTR_ERR(index); - index = NULL; - goto out_put; + (!d->is_dir || ovl_index_all(dentry->d_sb))) { + ctx->index = ovl_lookup_index(ofs, ctx->upperdentry, origin, true); + if (IS_ERR(ctx->index)) { + err = PTR_ERR(ctx->index); + ctx->index = NULL; + return err; } } - if (ctr) { - oe = ovl_alloc_entry(ctr); + if (ctx->ctr) { + ctx->oe = ovl_alloc_entry(ctx->ctr); err = -ENOMEM; - if (!oe) - goto out_put; + if (!ctx->oe) + return err; - ovl_stack_cpy(ovl_lowerstack(oe), stack, ctr); + ovl_stack_cpy(ovl_lowerstack(ctx->oe), ctx->stack, ctx->ctr); } if (upperopaque) ovl_dentry_set_opaque(dentry); - if (d.xwhiteouts) + if (d->xwhiteouts) ovl_dentry_set_xwhiteouts(dentry); - if (upperdentry) + if (ctx->upperdentry) ovl_dentry_set_upper_alias(dentry); - else if (index) { + else if (ctx->index) { + char *upperredirect; struct path upperpath = { - .dentry = upperdentry = dget(index), + .dentry = ctx->upperdentry = dget(ctx->index), .mnt = ovl_upper_mnt(ofs), }; @@ -1343,84 +1324,100 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * assignment happens only if upperdentry is non-NULL, and * this one only if upperdentry is NULL. */ - d.upperredirect = ovl_get_redirect_xattr(ofs, &upperpath, 0); - if (IS_ERR(d.upperredirect)) { - err = PTR_ERR(d.upperredirect); - d.upperredirect = NULL; - goto out_free_oe; - } + upperredirect = ovl_get_redirect_xattr(ofs, &upperpath, 0); + if (IS_ERR(upperredirect)) + return PTR_ERR(upperredirect); + d->upperredirect = upperredirect; err = ovl_check_metacopy_xattr(ofs, &upperpath, NULL); if (err < 0) - goto out_free_oe; - d.metacopy = uppermetacopy = err; + return err; + d->metacopy = uppermetacopy = err; metacopy_size = err; - if (!ovl_check_follow_redirect(&d)) { + if (!ovl_check_follow_redirect(d)) { err = -EPERM; - goto out_free_oe; + return err; } } - if (upperdentry || ctr) { + if (ctx->upperdentry || ctx->ctr) { + struct inode *inode; struct ovl_inode_params oip = { - .upperdentry = upperdentry, - .oe = oe, - .index = index, - .redirect = d.upperredirect, + .upperdentry = ctx->upperdentry, + .oe = ctx->oe, + .index = ctx->index, + .redirect = d->upperredirect, }; /* Store lowerdata redirect for lazy lookup */ - if (ctr > 1 && !d.is_dir && !stack[ctr - 1].dentry) { - oip.lowerdata_redirect = d.redirect; - d.redirect = NULL; + if (ctx->ctr > 1 && !d->is_dir && !ctx->stack[ctx->ctr - 1].dentry) { + oip.lowerdata_redirect = d->redirect; + d->redirect = NULL; } + inode = ovl_get_inode(dentry->d_sb, &oip); - err = PTR_ERR(inode); if (IS_ERR(inode)) - goto out_free_oe; - if (upperdentry && !uppermetacopy) - ovl_set_flag(OVL_UPPERDATA, inode); + return PTR_ERR(inode); + + ctx->inode = inode; + if (ctx->upperdentry && !uppermetacopy) + ovl_set_flag(OVL_UPPERDATA, ctx->inode); if (metacopy_size > OVL_METACOPY_MIN_SIZE) - ovl_set_flag(OVL_HAS_DIGEST, inode); + ovl_set_flag(OVL_HAS_DIGEST, ctx->inode); } - ovl_dentry_init_reval(dentry, upperdentry, OVL_I_E(inode)); + ovl_dentry_init_reval(dentry, ctx->upperdentry, OVL_I_E(ctx->inode)); + + return 0; +} + +struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + struct ovl_fs *ofs = OVL_FS(dentry->d_sb); + struct ovl_entry *poe = OVL_E(dentry->d_parent); + bool check_redirect = (ovl_redirect_follow(ofs) || ofs->numdatalayer); + int err; + struct ovl_lookup_ctx ctx = { + .dentry = dentry, + }; + struct ovl_lookup_data d = { + .sb = dentry->d_sb, + .dentry = dentry, + .name = dentry->d_name, + .last = check_redirect ? false : !ovl_numlower(poe), + }; + + if (dentry->d_name.len > ofs->namelen) + return ERR_PTR(-ENAMETOOLONG); + + with_ovl_creds(dentry->d_sb) + err = ovl_lookup_layers(&ctx, &d); - ovl_revert_creds(old_cred); - if (origin_path) { - dput(origin_path->dentry); - kfree(origin_path); + if (ctx.origin_path) { + dput(ctx.origin_path->dentry); + kfree(ctx.origin_path); } - dput(index); - ovl_stack_free(stack, ctr); + dput(ctx.index); + ovl_stack_free(ctx.stack, ctx.ctr); kfree(d.redirect); - return d_splice_alias(inode, dentry); -out_free_oe: - ovl_free_entry(oe); -out_put: - dput(index); - ovl_stack_free(stack, ctr); -out_put_upper: - if (origin_path) { - dput(origin_path->dentry); - kfree(origin_path); + if (err) { + ovl_free_entry(ctx.oe); + dput(ctx.upperdentry); + kfree(d.upperredirect); + return ERR_PTR(err); } - dput(upperdentry); - kfree(d.upperredirect); -out: - kfree(d.redirect); - ovl_revert_creds(old_cred); - return ERR_PTR(err); + + return d_splice_alias(ctx.inode, dentry); } bool ovl_lower_positive(struct dentry *dentry) { struct ovl_entry *poe = OVL_E(dentry->d_parent); const struct qstr *name = &dentry->d_name; - const struct cred *old_cred; unsigned int i; bool positive = false; bool done = false; @@ -1436,46 +1433,45 @@ bool ovl_lower_positive(struct dentry *dentry) if (!ovl_dentry_upper(dentry)) return true; - old_cred = ovl_override_creds(dentry->d_sb); - /* Positive upper -> have to look up lower to see whether it exists */ - for (i = 0; !done && !positive && i < ovl_numlower(poe); i++) { - struct dentry *this; - struct ovl_path *parentpath = &ovl_lowerstack(poe)[i]; + with_ovl_creds(dentry->d_sb) { + /* Positive upper -> have to look up lower to see whether it exists */ + for (i = 0; !done && !positive && i < ovl_numlower(poe); i++) { + struct dentry *this; + struct ovl_path *parentpath = &ovl_lowerstack(poe)[i]; - /* - * We need to make a non-const copy of dentry->d_name, - * because lookup_one_positive_unlocked() will hash name - * with parentpath base, which is on another (lower fs). - */ - this = lookup_one_positive_unlocked( - mnt_idmap(parentpath->layer->mnt), - &QSTR_LEN(name->name, name->len), - parentpath->dentry); - if (IS_ERR(this)) { - switch (PTR_ERR(this)) { - case -ENOENT: - case -ENAMETOOLONG: - break; - - default: - /* - * Assume something is there, we just couldn't - * access it. - */ - positive = true; - break; + /* + * We need to make a non-const copy of dentry->d_name, + * because lookup_one_positive_unlocked() will hash name + * with parentpath base, which is on another (lower fs). + */ + this = lookup_one_positive_unlocked(mnt_idmap(parentpath->layer->mnt), + &QSTR_LEN(name->name, name->len), + parentpath->dentry); + if (IS_ERR(this)) { + switch (PTR_ERR(this)) { + case -ENOENT: + case -ENAMETOOLONG: + break; + + default: + /* + * Assume something is there, we just couldn't + * access it. + */ + positive = true; + break; + } + } else { + struct path path = { + .dentry = this, + .mnt = parentpath->layer->mnt, + }; + positive = !ovl_path_is_whiteout(OVL_FS(dentry->d_sb), &path); + done = true; + dput(this); } - } else { - struct path path = { - .dentry = this, - .mnt = parentpath->layer->mnt, - }; - positive = !ovl_path_is_whiteout(OVL_FS(dentry->d_sb), &path); - done = true; - dput(this); } } - ovl_revert_creds(old_cred); return positive; } diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index c8fd5951fc5e..f9ac9bdde830 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -206,7 +206,7 @@ static inline int ovl_do_notify_change(struct ovl_fs *ofs, static inline int ovl_do_rmdir(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry) { - int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); + int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); pr_debug("rmdir(%pd2) = %i\n", dentry, err); return err; @@ -235,7 +235,7 @@ static inline int ovl_do_create(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry, umode_t mode) { - int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); + int err = vfs_create(ovl_upper_mnt_idmap(ofs), dentry, mode, NULL); pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); return err; @@ -248,7 +248,7 @@ static inline struct dentry *ovl_do_mkdir(struct ovl_fs *ofs, { struct dentry *ret; - ret = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); + ret = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, NULL); pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(ret)); return ret; } @@ -257,7 +257,7 @@ static inline int ovl_do_mknod(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { - int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); + int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev, NULL); pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); return err; @@ -267,7 +267,7 @@ static inline int ovl_do_symlink(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry, const char *oldname) { - int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); + int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname, NULL); pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); return err; @@ -355,11 +355,24 @@ static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); } +static inline int ovl_do_rename_rd(struct renamedata *rd) +{ + int err; + + pr_debug("rename(%pd2, %pd2, 0x%x)\n", rd->old_dentry, rd->new_dentry, + rd->flags); + err = vfs_rename(rd); + if (err) { + pr_debug("...rename(%pd2, %pd2, ...) = %i\n", + rd->old_dentry, rd->new_dentry, err); + } + return err; +} + static inline int ovl_do_rename(struct ovl_fs *ofs, struct dentry *olddir, struct dentry *olddentry, struct dentry *newdir, struct dentry *newdentry, unsigned int flags) { - int err; struct renamedata rd = { .mnt_idmap = ovl_upper_mnt_idmap(ofs), .old_parent = olddir, @@ -369,13 +382,7 @@ static inline int ovl_do_rename(struct ovl_fs *ofs, struct dentry *olddir, .flags = flags, }; - pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); - err = vfs_rename(&rd); - if (err) { - pr_debug("...rename(%pd2, %pd2, ...) = %i\n", - olddentry, newdentry, err); - } - return err; + return ovl_do_rename_rd(&rd); } static inline int ovl_do_whiteout(struct ovl_fs *ofs, @@ -415,6 +422,22 @@ static inline struct dentry *ovl_lookup_upper_unlocked(struct ovl_fs *ofs, &QSTR_LEN(name, len), base); } +static inline struct dentry *ovl_start_creating_upper(struct ovl_fs *ofs, + struct dentry *parent, + struct qstr *name) +{ + return start_creating(ovl_upper_mnt_idmap(ofs), + parent, name); +} + +static inline struct dentry *ovl_start_removing_upper(struct ovl_fs *ofs, + struct dentry *parent, + struct qstr *name) +{ + return start_removing(ovl_upper_mnt_idmap(ofs), + parent, name); +} + static inline bool ovl_open_flags_need_copy_up(int flags) { if (!flags) @@ -424,11 +447,6 @@ static inline bool ovl_open_flags_need_copy_up(int flags) } /* util.c */ -int ovl_parent_lock(struct dentry *parent, struct dentry *child); -static inline void ovl_parent_unlock(struct dentry *parent) -{ - inode_unlock(parent->d_inode); -} int ovl_get_write_access(struct dentry *dentry); void ovl_put_write_access(struct dentry *dentry); void ovl_start_write(struct dentry *dentry); @@ -437,7 +455,11 @@ int ovl_want_write(struct dentry *dentry); void ovl_drop_write(struct dentry *dentry); struct dentry *ovl_workdir(struct dentry *dentry); const struct cred *ovl_override_creds(struct super_block *sb); -void ovl_revert_creds(const struct cred *old_cred); + +EXTEND_CLASS(override_creds, _ovl, ovl_override_creds(sb), struct super_block *sb) + +#define with_ovl_creds(sb) \ + scoped_class(override_creds_ovl, __UNIQUE_ID(label), sb) static inline const struct cred *ovl_creds(struct super_block *sb) { @@ -865,7 +887,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct dentry *parent, struct dentry *newdentry, struct ovl_cattr *attr); int ovl_cleanup(struct ovl_fs *ofs, struct dentry *workdir, struct dentry *dentry); -struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); +#define OVL_TEMPNAME_SIZE 20 +void ovl_tempname(char name[OVL_TEMPNAME_SIZE]); struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, struct ovl_cattr *attr); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 1e9792cc557b..160960bb0ad0 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -348,11 +348,7 @@ static bool ovl_fill_merge(struct dir_context *ctx, const char *name, static int ovl_check_whiteouts(const struct path *path, struct ovl_readdir_data *rdd) { - int err = 0; struct dentry *dentry, *dir = path->dentry; - const struct cred *old_cred; - - old_cred = ovl_override_creds(rdd->dentry->d_sb); while (rdd->first_maybe_whiteout) { struct ovl_cache_entry *p = @@ -365,13 +361,11 @@ static int ovl_check_whiteouts(const struct path *path, struct ovl_readdir_data p->is_whiteout = ovl_is_whiteout(dentry); dput(dentry); } else if (PTR_ERR(dentry) == -EINTR) { - err = -EINTR; - break; + return -EINTR; } } - ovl_revert_creds(old_cred); - return err; + return 0; } static inline int ovl_dir_read(const struct path *realpath, @@ -838,36 +832,12 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx) return err; } - -static int ovl_iterate(struct file *file, struct dir_context *ctx) +static int ovl_iterate_merged(struct file *file, struct dir_context *ctx) { struct ovl_dir_file *od = file->private_data; struct dentry *dentry = file->f_path.dentry; - struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct ovl_cache_entry *p; - const struct cred *old_cred; - int err; - - old_cred = ovl_override_creds(dentry->d_sb); - if (!ctx->pos) - ovl_dir_reset(file); - - if (od->is_real) { - /* - * If parent is merge, then need to adjust d_ino for '..', if - * dir is impure then need to adjust d_ino for copied up - * entries. - */ - if (ovl_xino_bits(ofs) || - (ovl_same_fs(ofs) && - (ovl_is_impure_dir(file) || - OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) { - err = ovl_iterate_real(file, ctx); - } else { - err = iterate_dir(od->realfile, ctx); - } - goto out; - } + int err = 0; if (!od->cache) { struct ovl_dir_cache *cache; @@ -875,7 +845,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) cache = ovl_cache_get(dentry); err = PTR_ERR(cache); if (IS_ERR(cache)) - goto out; + return err; od->cache = cache; ovl_seek_cursor(od, ctx->pos); @@ -887,7 +857,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) if (!p->ino || p->check_xwhiteout) { err = ovl_cache_update(&file->f_path, p, !p->ino); if (err) - goto out; + return err; } } /* ovl_cache_update() sets is_whiteout on stale entry */ @@ -898,12 +868,50 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) od->cursor = p->l_node.next; ctx->pos++; } - err = 0; -out: - ovl_revert_creds(old_cred); return err; } +static bool ovl_need_adjust_d_ino(struct file *file) +{ + struct dentry *dentry = file->f_path.dentry; + struct ovl_fs *ofs = OVL_FS(dentry->d_sb); + + /* If parent is merge, then need to adjust d_ino for '..' */ + if (ovl_xino_bits(ofs)) + return true; + + /* Can't do consistent inode numbering */ + if (!ovl_same_fs(ofs)) + return false; + + /* If dir is impure then need to adjust d_ino for copied up entries */ + if (ovl_is_impure_dir(file) || + OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))) + return true; + + /* Pure: no need to adjust d_ino */ + return false; +} + + +static int ovl_iterate(struct file *file, struct dir_context *ctx) +{ + struct ovl_dir_file *od = file->private_data; + + if (!ctx->pos) + ovl_dir_reset(file); + + with_ovl_creds(file_dentry(file)->d_sb) { + if (!od->is_real) + return ovl_iterate_merged(file, ctx); + + if (ovl_need_adjust_d_ino(file)) + return ovl_iterate_real(file, ctx); + + return iterate_dir(od->realfile, ctx); + } +} + static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin) { loff_t res; @@ -947,14 +955,8 @@ out_unlock: static struct file *ovl_dir_open_realfile(const struct file *file, const struct path *realpath) { - struct file *res; - const struct cred *old_cred; - - old_cred = ovl_override_creds(file_inode(file)->i_sb); - res = ovl_path_open(realpath, O_RDONLY | (file->f_flags & O_LARGEFILE)); - ovl_revert_creds(old_cred); - - return res; + with_ovl_creds(file_inode(file)->i_sb) + return ovl_path_open(realpath, O_RDONLY | (file->f_flags & O_LARGEFILE)); } /* @@ -1075,11 +1077,9 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) int err; struct ovl_cache_entry *p, *n; struct rb_root root = RB_ROOT; - const struct cred *old_cred; - old_cred = ovl_override_creds(dentry->d_sb); - err = ovl_dir_read_merged(dentry, list, &root); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + err = ovl_dir_read_merged(dentry, list, &root); if (err) return err; @@ -1242,11 +1242,11 @@ int ovl_workdir_cleanup(struct ovl_fs *ofs, struct dentry *parent, if (!d_is_dir(dentry) || level > 1) return ovl_cleanup(ofs, parent, dentry); - err = ovl_parent_lock(parent, dentry); - if (err) - return err; + dentry = start_removing_dentry(parent, dentry); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); err = ovl_do_rmdir(ofs, parent->d_inode, dentry); - ovl_parent_unlock(parent); + end_removing(dentry); if (err) { struct path path = { .mnt = mnt, .dentry = dentry }; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 43ee4c7296a7..28b2f707cfbc 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -310,8 +310,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs, bool retried = false; retry: - inode_lock_nested(dir, I_MUTEX_PARENT); - work = ovl_lookup_upper(ofs, name, ofs->workbasedir, strlen(name)); + work = ovl_start_creating_upper(ofs, ofs->workbasedir, &QSTR(name)); if (!IS_ERR(work)) { struct iattr attr = { @@ -320,14 +319,12 @@ retry: }; if (work->d_inode) { + end_creating_keep(work); + if (persist) + return work; err = -EEXIST; - inode_unlock(dir); if (retried) goto out_dput; - - if (persist) - return work; - retried = true; err = ovl_workdir_cleanup(ofs, ofs->workbasedir, mnt, work, 0); dput(work); @@ -338,7 +335,7 @@ retry: } work = ovl_do_mkdir(ofs, dir, work, attr.ia_mode); - inode_unlock(dir); + end_creating_keep(work); err = PTR_ERR(work); if (IS_ERR(work)) goto out_err; @@ -376,7 +373,6 @@ retry: if (err) goto out_dput; } else { - inode_unlock(dir); err = PTR_ERR(work); goto out_err; } @@ -567,9 +563,10 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs) { struct dentry *workdir = ofs->workdir; struct dentry *temp; - struct dentry *dest; struct dentry *whiteout; struct name_snapshot name; + struct renamedata rd = {}; + char name2[OVL_TEMPNAME_SIZE]; int err; temp = ovl_create_temp(ofs, workdir, OVL_CATTR(S_IFREG | 0)); @@ -577,23 +574,21 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs) if (IS_ERR(temp)) return err; - err = ovl_parent_lock(workdir, temp); + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = workdir; + rd.new_parent = workdir; + rd.flags = RENAME_WHITEOUT; + ovl_tempname(name2); + err = start_renaming_dentry(&rd, 0, temp, &QSTR(name2)); if (err) { dput(temp); return err; } - dest = ovl_lookup_temp(ofs, workdir); - err = PTR_ERR(dest); - if (IS_ERR(dest)) { - dput(temp); - ovl_parent_unlock(workdir); - return err; - } /* Name is inline and stable - using snapshot as a copy helper */ take_dentry_name_snapshot(&name, temp); - err = ovl_do_rename(ofs, workdir, temp, workdir, dest, RENAME_WHITEOUT); - ovl_parent_unlock(workdir); + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); if (err) { if (err == -EINVAL) err = 0; @@ -617,7 +612,6 @@ cleanup_temp: ovl_cleanup(ofs, workdir, temp); release_dentry_name_snapshot(&name); dput(temp); - dput(dest); return err; } @@ -626,14 +620,15 @@ static struct dentry *ovl_lookup_or_create(struct ovl_fs *ofs, struct dentry *parent, const char *name, umode_t mode) { - size_t len = strlen(name); struct dentry *child; - inode_lock_nested(parent->d_inode, I_MUTEX_PARENT); - child = ovl_lookup_upper(ofs, name, parent, len); - if (!IS_ERR(child) && !child->d_inode) - child = ovl_create_real(ofs, parent, child, OVL_CATTR(mode)); - inode_unlock(parent->d_inode); + child = ovl_start_creating_upper(ofs, parent, &QSTR(name)); + if (!IS_ERR(child)) { + if (!child->d_inode) + child = ovl_create_real(ofs, parent, child, + OVL_CATTR(mode)); + end_creating_keep(child); + } dput(parent); return child; @@ -1369,53 +1364,35 @@ static void ovl_set_d_op(struct super_block *sb) set_default_d_op(sb, &ovl_dentry_operations); } -int ovl_fill_super(struct super_block *sb, struct fs_context *fc) +static int ovl_fill_super_creds(struct fs_context *fc, struct super_block *sb) { struct ovl_fs *ofs = sb->s_fs_info; + struct cred *creator_cred = (struct cred *)ofs->creator_cred; struct ovl_fs_context *ctx = fc->fs_private; - const struct cred *old_cred = NULL; - struct dentry *root_dentry; - struct ovl_entry *oe; struct ovl_layer *layers; - struct cred *cred; + struct ovl_entry *oe = NULL; int err; - err = -EIO; - if (WARN_ON(fc->user_ns != current_user_ns())) - goto out_err; - - ovl_set_d_op(sb); - - err = -ENOMEM; - if (!ofs->creator_cred) - ofs->creator_cred = cred = prepare_creds(); - else - cred = (struct cred *)ofs->creator_cred; - if (!cred) - goto out_err; - - old_cred = ovl_override_creds(sb); - err = ovl_fs_params_verify(ctx, &ofs->config); if (err) - goto out_err; + return err; err = -EINVAL; if (ctx->nr == 0) { if (!(fc->sb_flags & SB_SILENT)) pr_err("missing 'lowerdir'\n"); - goto out_err; + return err; } err = -ENOMEM; layers = kcalloc(ctx->nr + 1, sizeof(struct ovl_layer), GFP_KERNEL); if (!layers) - goto out_err; + return err; ofs->config.lowerdirs = kcalloc(ctx->nr + 1, sizeof(char *), GFP_KERNEL); if (!ofs->config.lowerdirs) { kfree(layers); - goto out_err; + return err; } ofs->layers = layers; /* @@ -1448,12 +1425,12 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) err = -EINVAL; if (!ofs->config.workdir) { pr_err("missing 'workdir'\n"); - goto out_err; + return err; } err = ovl_get_upper(sb, ofs, &layers[0], &ctx->upper); if (err) - goto out_err; + return err; upper_sb = ovl_upper_mnt(ofs)->mnt_sb; if (!ovl_should_sync(ofs)) { @@ -1461,13 +1438,13 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) if (errseq_check(&upper_sb->s_wb_err, ofs->errseq)) { err = -EIO; pr_err("Cannot mount volatile when upperdir has an unseen error. Sync upperdir fs to clear state.\n"); - goto out_err; + return err; } } err = ovl_get_workdir(sb, ofs, &ctx->upper, &ctx->work); if (err) - goto out_err; + return err; if (!ofs->workdir) sb->s_flags |= SB_RDONLY; @@ -1478,7 +1455,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) oe = ovl_get_lowerstack(sb, ctx, ofs, layers); err = PTR_ERR(oe); if (IS_ERR(oe)) - goto out_err; + return err; /* If the upper fs is nonexistent, we mark overlayfs r/o too */ if (!ovl_upper_mnt(ofs)) @@ -1531,7 +1508,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_export_op = &ovl_export_fid_operations; /* Never override disk quota limits or use reserved space */ - cap_lower(cred->cap_effective, CAP_SYS_RESOURCE); + cap_lower(creator_cred->cap_effective, CAP_SYS_RESOURCE); sb->s_magic = OVERLAYFS_SUPER_MAGIC; sb->s_xattr = ovl_xattr_handlers(ofs); @@ -1549,27 +1526,44 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_iflags |= SB_I_EVM_HMAC_UNSUPPORTED; err = -ENOMEM; - root_dentry = ovl_get_root(sb, ctx->upper.dentry, oe); - if (!root_dentry) + sb->s_root = ovl_get_root(sb, ctx->upper.dentry, oe); + if (!sb->s_root) goto out_free_oe; - sb->s_root = root_dentry; - - ovl_revert_creds(old_cred); return 0; out_free_oe: ovl_free_entry(oe); + return err; +} + +int ovl_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct ovl_fs *ofs = sb->s_fs_info; + int err; + + err = -EIO; + if (WARN_ON(fc->user_ns != current_user_ns())) + goto out_err; + + ovl_set_d_op(sb); + + if (!ofs->creator_cred) { + err = -ENOMEM; + ofs->creator_cred = prepare_creds(); + if (!ofs->creator_cred) + goto out_err; + } + + with_ovl_creds(sb) + err = ovl_fill_super_creds(fc, sb); + out_err: - /* - * Revert creds before calling ovl_free_fs() which will call - * put_cred() and put_cred() requires that the cred's that are - * put are not the caller's creds, i.e., current->cred. - */ - if (old_cred) - ovl_revert_creds(old_cred); - ovl_free_fs(ofs); - sb->s_fs_info = NULL; + if (err) { + ovl_free_fs(ofs); + sb->s_fs_info = NULL; + } + return err; } diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index f76672f2e686..94986d11a166 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -69,11 +69,6 @@ const struct cred *ovl_override_creds(struct super_block *sb) return override_creds(ofs->creator_cred); } -void ovl_revert_creds(const struct cred *old_cred) -{ - revert_creds(old_cred); -} - /* * Check if underlying fs supports file handles and try to determine encoding * type, in order to deduce maximum inode number used by fs. @@ -1019,8 +1014,8 @@ bool ovl_inuse_trylock(struct dentry *dentry) bool locked = false; spin_lock(&inode->i_lock); - if (!(inode->i_state & I_OVL_INUSE)) { - inode->i_state |= I_OVL_INUSE; + if (!(inode_state_read(inode) & I_OVL_INUSE)) { + inode_state_set(inode, I_OVL_INUSE); locked = true; } spin_unlock(&inode->i_lock); @@ -1034,8 +1029,8 @@ void ovl_inuse_unlock(struct dentry *dentry) struct inode *inode = d_inode(dentry); spin_lock(&inode->i_lock); - WARN_ON(!(inode->i_state & I_OVL_INUSE)); - inode->i_state &= ~I_OVL_INUSE; + WARN_ON(!(inode_state_read(inode) & I_OVL_INUSE)); + inode_state_clear(inode, I_OVL_INUSE); spin_unlock(&inode->i_lock); } } @@ -1046,7 +1041,7 @@ bool ovl_is_inuse(struct dentry *dentry) bool inuse; spin_lock(&inode->i_lock); - inuse = (inode->i_state & I_OVL_INUSE); + inuse = (inode_state_read(inode) & I_OVL_INUSE); spin_unlock(&inode->i_lock); return inuse; @@ -1147,7 +1142,6 @@ fail: int ovl_nlink_start(struct dentry *dentry) { struct inode *inode = d_inode(dentry); - const struct cred *old_cred; int err; if (WARN_ON(!inode)) @@ -1184,15 +1178,14 @@ int ovl_nlink_start(struct dentry *dentry) if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, inode)) return 0; - old_cred = ovl_override_creds(dentry->d_sb); /* * The overlay inode nlink should be incremented/decremented IFF the * upper operation succeeds, along with nlink change of upper inode. * Therefore, before link/unlink/rename, we store the union nlink * value relative to the upper inode nlink in an upper inode xattr. */ - err = ovl_set_nlink_upper(dentry); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + err = ovl_set_nlink_upper(dentry); if (err) goto out_drop_write; @@ -1213,11 +1206,8 @@ void ovl_nlink_end(struct dentry *dentry) ovl_drop_write(dentry); if (ovl_test_flag(OVL_INDEX, inode) && inode->i_nlink == 0) { - const struct cred *old_cred; - - old_cred = ovl_override_creds(dentry->d_sb); - ovl_cleanup_index(dentry); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + ovl_cleanup_index(dentry); } ovl_inode_unlock(inode); @@ -1234,9 +1224,9 @@ int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *work, goto err; if (trap) goto err_unlock; - if (work && work->d_parent != workdir) + if (work && (work->d_parent != workdir || d_unhashed(work))) goto err_unlock; - if (upper && upper->d_parent != upperdir) + if (upper && (upper->d_parent != upperdir || d_unhashed(upper))) goto err_unlock; return 0; @@ -1548,14 +1538,3 @@ void ovl_copyattr(struct inode *inode) i_size_write(inode, i_size_read(realinode)); spin_unlock(&inode->i_lock); } - -int ovl_parent_lock(struct dentry *parent, struct dentry *child) -{ - inode_lock_nested(parent->d_inode, I_MUTEX_PARENT); - if (!child || - (!d_unhashed(child) && child->d_parent == parent)) - return 0; - - inode_unlock(parent->d_inode); - return -EINVAL; -} diff --git a/fs/overlayfs/xattrs.c b/fs/overlayfs/xattrs.c index 88055deca936..aa95855c7023 100644 --- a/fs/overlayfs/xattrs.c +++ b/fs/overlayfs/xattrs.c @@ -41,13 +41,11 @@ static int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char struct dentry *upperdentry = ovl_i_dentry_upper(inode); struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry); struct path realpath; - const struct cred *old_cred; if (!value && !upperdentry) { ovl_path_lower(dentry, &realpath); - old_cred = ovl_override_creds(dentry->d_sb); - err = vfs_getxattr(mnt_idmap(realpath.mnt), realdentry, name, NULL, 0); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + err = vfs_getxattr(mnt_idmap(realpath.mnt), realdentry, name, NULL, 0); if (err < 0) goto out; } @@ -64,15 +62,14 @@ static int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char if (err) goto out; - old_cred = ovl_override_creds(dentry->d_sb); - if (value) { - err = ovl_do_setxattr(ofs, realdentry, name, value, size, - flags); - } else { - WARN_ON(flags != XATTR_REPLACE); - err = ovl_do_removexattr(ofs, realdentry, name); + with_ovl_creds(dentry->d_sb) { + if (value) { + err = ovl_do_setxattr(ofs, realdentry, name, value, size, flags); + } else { + WARN_ON(flags != XATTR_REPLACE); + err = ovl_do_removexattr(ofs, realdentry, name); + } } - ovl_revert_creds(old_cred); ovl_drop_write(dentry); /* copy c/mtime */ @@ -84,15 +81,11 @@ out: static int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, void *value, size_t size) { - ssize_t res; - const struct cred *old_cred; struct path realpath; ovl_i_path_real(inode, &realpath); - old_cred = ovl_override_creds(dentry->d_sb); - res = vfs_getxattr(mnt_idmap(realpath.mnt), realpath.dentry, name, value, size); - ovl_revert_creds(old_cred); - return res; + with_ovl_creds(dentry->d_sb) + return vfs_getxattr(mnt_idmap(realpath.mnt), realpath.dentry, name, value, size); } static bool ovl_can_list(struct super_block *sb, const char *s) @@ -116,12 +109,10 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) ssize_t res; size_t len; char *s; - const struct cred *old_cred; size_t prefix_len, name_len; - old_cred = ovl_override_creds(dentry->d_sb); - res = vfs_listxattr(realdentry, list, size); - ovl_revert_creds(old_cred); + with_ovl_creds(dentry->d_sb) + res = vfs_listxattr(realdentry, list, size); if (res <= 0 || size == 0) return res; |