diff options
Diffstat (limited to '')
-rw-r--r-- | fs/overlayfs/namei.c | 91 |
1 files changed, 63 insertions, 28 deletions
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 80391c687c..22c29e540e 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -18,10 +18,11 @@ struct ovl_lookup_data { struct super_block *sb; - struct vfsmount *mnt; + const struct ovl_layer *layer; struct qstr name; bool is_dir; bool opaque; + bool xwhiteouts; bool stop; bool last; char *redirect; @@ -201,17 +202,13 @@ struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, return real; } -static bool ovl_is_opaquedir(struct ovl_fs *ofs, const struct path *path) -{ - return ovl_path_check_dir_xattr(ofs, path, OVL_XATTR_OPAQUE); -} - static struct dentry *ovl_lookup_positive_unlocked(struct ovl_lookup_data *d, const char *name, struct dentry *base, int len, bool drop_negative) { - struct dentry *ret = lookup_one_unlocked(mnt_idmap(d->mnt), name, base, len); + struct dentry *ret = lookup_one_unlocked(mnt_idmap(d->layer->mnt), name, + base, len); if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) { if (drop_negative && ret->d_lockref.count == 1) { @@ -232,10 +229,13 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, size_t prelen, const char *post, struct dentry **ret, bool drop_negative) { + struct ovl_fs *ofs = OVL_FS(d->sb); struct dentry *this; struct path path; int err; bool last_element = !post[0]; + bool is_upper = d->layer->idx == 0; + char val; this = ovl_lookup_positive_unlocked(d, name, base, namelen, drop_negative); if (IS_ERR(this)) { @@ -251,7 +251,10 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, err = -EREMOTE; goto out_err; } - if (ovl_is_whiteout(this)) { + + path.dentry = this; + path.mnt = d->layer->mnt; + if (ovl_path_is_whiteout(ofs, &path)) { d->stop = d->opaque = true; goto put_and_out; } @@ -264,14 +267,12 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, goto put_and_out; } - path.dentry = this; - path.mnt = d->mnt; if (!d_can_lookup(this)) { if (d->is_dir || !last_element) { d->stop = true; goto put_and_out; } - err = ovl_check_metacopy_xattr(OVL_FS(d->sb), &path, NULL); + err = ovl_check_metacopy_xattr(ofs, &path, NULL); if (err < 0) goto out_err; @@ -291,7 +292,12 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, if (d->last) goto out; - if (ovl_is_opaquedir(OVL_FS(d->sb), &path)) { + /* overlay.opaque=x means xwhiteouts directory */ + val = ovl_get_opaquedir_val(ofs, &path); + if (last_element && !is_upper && val == 'x') { + d->xwhiteouts = true; + ovl_layer_set_xwhiteouts(ofs, d->layer); + } else if (val == 'y') { d->stop = true; if (last_element) d->opaque = true; @@ -438,7 +444,7 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, else if (IS_ERR(origin)) return PTR_ERR(origin); - if (upperdentry && !ovl_is_whiteout(upperdentry) && + if (upperdentry && !ovl_upper_is_whiteout(ofs, upperdentry) && inode_wrong_type(d_inode(upperdentry), d_inode(origin)->i_mode)) goto invalid; @@ -507,6 +513,19 @@ static int ovl_verify_fh(struct ovl_fs *ofs, struct dentry *dentry, return err; } +int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, + enum ovl_xattr ox, const struct ovl_fh *fh, + bool is_upper, bool set) +{ + int err; + + err = ovl_verify_fh(ofs, dentry, ox, fh); + if (set && err == -ENODATA) + err = ovl_setxattr(ofs, dentry, ox, fh->buf, fh->fb.len); + + return err; +} + /* * Verify that @real dentry matches the file handle stored in xattr @name. * @@ -515,9 +534,9 @@ static int ovl_verify_fh(struct ovl_fs *ofs, struct dentry *dentry, * * Return 0 on match, -ESTALE on mismatch, -ENODATA on no xattr, < 0 on error. */ -int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, - enum ovl_xattr ox, struct dentry *real, bool is_upper, - bool set) +int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, + enum ovl_xattr ox, struct dentry *real, + bool is_upper, bool set) { struct inode *inode; struct ovl_fh *fh; @@ -530,9 +549,7 @@ int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, goto fail; } - err = ovl_verify_fh(ofs, dentry, ox, fh); - if (set && err == -ENODATA) - err = ovl_setxattr(ofs, dentry, ox, fh->buf, fh->fb.len); + err = ovl_verify_set_fh(ofs, dentry, ox, fh, is_upper, set); if (err) goto fail; @@ -548,6 +565,7 @@ fail: goto out; } + /* Get upper dentry from index */ struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, bool connected) @@ -684,7 +702,7 @@ orphan: goto out; } -static int ovl_get_index_name_fh(struct ovl_fh *fh, struct qstr *name) +int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name) { char *n, *s; @@ -850,7 +868,8 @@ fail: * Returns next layer in stack starting from top. * Returns -1 if this is the last layer. */ -int ovl_path_next(int idx, struct dentry *dentry, struct path *path) +int ovl_path_next(int idx, struct dentry *dentry, struct path *path, + const struct ovl_layer **layer) { struct ovl_entry *oe = OVL_E(dentry); struct ovl_path *lowerstack = ovl_lowerstack(oe); @@ -858,13 +877,16 @@ int ovl_path_next(int idx, struct dentry *dentry, struct path *path) BUG_ON(idx < 0); if (idx == 0) { ovl_path_upper(dentry, path); - if (path->dentry) + if (path->dentry) { + *layer = &OVL_FS(dentry->d_sb)->layers[0]; return ovl_numlower(oe) ? 1 : -1; + } idx++; } BUG_ON(idx > ovl_numlower(oe)); path->dentry = lowerstack[idx - 1].dentry; - path->mnt = lowerstack[idx - 1].layer->mnt; + *layer = lowerstack[idx - 1].layer; + path->mnt = (*layer)->mnt; return (idx < ovl_numlower(oe)) ? idx + 1 : -1; } @@ -873,20 +895,27 @@ int ovl_path_next(int idx, struct dentry *dentry, struct path *path) static int ovl_fix_origin(struct ovl_fs *ofs, struct dentry *dentry, struct dentry *lower, struct dentry *upper) { + const struct ovl_fh *fh; int err; if (ovl_check_origin_xattr(ofs, upper)) return 0; + fh = ovl_get_origin_fh(ofs, lower); + if (IS_ERR(fh)) + return PTR_ERR(fh); + err = ovl_want_write(dentry); if (err) - return err; + goto out; - err = ovl_set_origin(ofs, lower, upper); + err = ovl_set_origin_fh(ofs, fh, upper); if (!err) err = ovl_set_impure(dentry->d_parent, upper->d_parent); ovl_drop_write(dentry); +out: + kfree(fh); return err; } @@ -1035,7 +1064,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, old_cred = ovl_override_creds(dentry->d_sb); upperdir = ovl_dentry_upper(dentry->d_parent); if (upperdir) { - d.mnt = ovl_upper_mnt(ofs); + d.layer = &ofs->layers[0]; err = ovl_lookup_layer(upperdir, &d, &upperdentry, true); if (err) goto out; @@ -1091,7 +1120,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, else if (d.is_dir || !ofs->numdatalayer) d.last = lower.layer->idx == ovl_numlower(roe); - d.mnt = lower.layer->mnt; + d.layer = lower.layer; err = ovl_lookup_layer(lower.dentry, &d, &this, false); if (err) goto out_put; @@ -1258,6 +1287,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, if (upperopaque) ovl_dentry_set_opaque(dentry); + if (d.xwhiteouts) + ovl_dentry_set_xwhiteouts(dentry); if (upperdentry) ovl_dentry_set_upper_alias(dentry); @@ -1383,7 +1414,11 @@ bool ovl_lower_positive(struct dentry *dentry) break; } } else { - positive = !ovl_is_whiteout(this); + struct path path = { + .dentry = this, + .mnt = parentpath->layer->mnt, + }; + positive = !ovl_path_is_whiteout(OVL_FS(dentry->d_sb), &path); done = true; dput(this); } |