diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 768120c20f85..aab3f5d93556 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -477,7 +477,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, goto out_unlock; err = -ESTALE; - if (d_is_negative(upper) || !IS_WHITEOUT(d_inode(upper))) + if (d_is_negative(upper) || !ovl_upper_is_whiteout(ofs, upper)) goto out_dput; newdentry = ovl_create_temp(ofs, workdir, cattr); @@ -1211,7 +1211,7 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, } } else { if (!d_is_negative(newdentry)) { - if (!new_opaque || !ovl_is_whiteout(newdentry)) + if (!new_opaque || !ovl_upper_is_whiteout(ofs, newdentry)) goto out_dput; } else { if (flags & RENAME_EXCHANGE) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index f10ac4ae35f0..03bc8d5dfa31 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -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->mnt; + if (ovl_path_is_whiteout(OVL_FS(d->sb), &path)) { d->stop = d->opaque = true; goto put_and_out; } @@ -264,8 +267,6 @@ 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; @@ -438,7 +439,7 @@ 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; @@ -1402,7 +1403,11 @@ 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); } diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 393c6ba9bffa..ca88b2636a57 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -49,6 +49,8 @@ enum ovl_xattr { OVL_XATTR_UUID, OVL_XATTR_METACOPY, OVL_XATTR_PROTATTR, + OVL_XATTR_XWHITEOUT, + OVL_XATTR_XWHITEOUTS, }; enum ovl_inode_flag { @@ -473,6 +475,7 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); void ovl_dir_modified(struct dentry *dentry, bool impurity); u64 ovl_inode_version_get(struct inode *inode); bool ovl_is_whiteout(struct dentry *dentry); +bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); struct file *ovl_path_open(const struct path *path, int flags); int ovl_copy_up_start(struct dentry *dentry, int flags); void ovl_copy_up_end(struct dentry *dentry); @@ -480,9 +483,21 @@ bool ovl_already_copied_up(struct dentry *dentry, int flags); bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, enum ovl_xattr ox); bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); +bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); +bool ovl_path_check_xwhiteouts_xattr(struct ovl_fs *ofs, const struct path *path); bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, const struct path *upperpath); +static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, + struct dentry *upperdentry) +{ + struct path upperpath = { + .dentry = upperdentry, + .mnt = ovl_upper_mnt(ofs), + }; + return ovl_path_is_whiteout(ofs, &upperpath); +} + static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *upperdentry) { diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index de39e067ae65..a490fc47c3e7 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -25,6 +25,7 @@ struct ovl_cache_entry { struct ovl_cache_entry *next_maybe_whiteout; bool is_upper; bool is_whiteout; + bool check_xwhiteout; char name[]; }; @@ -47,6 +48,7 @@ struct ovl_readdir_data { int err; bool is_upper; bool d_type_supported; + bool in_xwhiteouts_dir; }; struct ovl_dir_file { @@ -162,6 +164,8 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, p->ino = 0; p->is_upper = rdd->is_upper; p->is_whiteout = false; + /* Defer check for overlay.whiteout to ovl_iterate() */ + p->check_xwhiteout = rdd->in_xwhiteouts_dir && d_type == DT_REG; if (d_type == DT_CHR) { p->next_maybe_whiteout = rdd->first_maybe_whiteout; @@ -301,6 +305,8 @@ static inline int ovl_dir_read(const struct path *realpath, if (IS_ERR(realfile)) return PTR_ERR(realfile); + rdd->in_xwhiteouts_dir = rdd->dentry && + ovl_path_check_xwhiteouts_xattr(OVL_FS(rdd->dentry->d_sb), realpath); rdd->first_maybe_whiteout = NULL; rdd->ctx.pos = 0; do { @@ -447,7 +453,7 @@ static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid, } /* - * Set d_ino for upper entries. Non-upper entries should always report + * Set d_ino for upper entries if needed. Non-upper entries should always report * the uppermost real inode ino and should not call this function. * * When not all layer are on same fs, report real ino also for upper. @@ -455,8 +461,11 @@ static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid, * When all layers are on the same fs, and upper has a reference to * copy up origin, call vfs_getattr() on the overlay entry to make * sure that d_ino will be consistent with st_ino from stat(2). + * + * Also checks the overlay.whiteout xattr by doing a full lookup which will return + * negative in this case. */ -static int ovl_cache_update_ino(const struct path *path, struct ovl_cache_entry *p) +static int ovl_cache_update(const struct path *path, struct ovl_cache_entry *p, bool update_ino) { struct dentry *dir = path->dentry; @@ -467,7 +476,7 @@ static int ovl_cache_update_ino(const struct path *path, struct ovl_cache_entry int xinobits = ovl_xino_bits(ofs); int err = 0; - if (!ovl_same_dev(ofs)) + if (!ovl_same_dev(ofs) && !p->check_xwhiteout) goto out; if (p->name[0] == '.') { @@ -481,6 +490,7 @@ static int ovl_cache_update_ino(const struct path *path, struct ovl_cache_entry goto get; } } + /* This checks also for xwhiteouts */ this = lookup_one(mnt_idmap(path->mnt), p->name, dir, p->len); if (IS_ERR_OR_NULL(this) || !this->d_inode) { /* Mark a stale entry */ @@ -494,6 +504,9 @@ static int ovl_cache_update_ino(const struct path *path, struct ovl_cache_entry } get: + if (!ovl_same_dev(ofs) || !update_ino) + goto out; + type = ovl_path_type(this); if (OVL_TYPE_ORIGIN(type)) { struct kstat stat; @@ -572,7 +585,7 @@ static int ovl_dir_read_impure(const struct path *path, struct list_head *list, list_for_each_entry_safe(p, n, list, l_node) { if (strcmp(p->name, ".") != 0 && strcmp(p->name, "..") != 0) { - err = ovl_cache_update_ino(path, p); + err = ovl_cache_update(path, p, true); if (err) return err; } @@ -778,13 +791,13 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) while (od->cursor != &od->cache->entries) { p = list_entry(od->cursor, struct ovl_cache_entry, l_node); if (!p->is_whiteout) { - if (!p->ino) { - err = ovl_cache_update_ino(&file->f_path, p); + if (!p->ino || p->check_xwhiteout) { + err = ovl_cache_update(&file->f_path, p, !p->ino); if (err) goto out; } } - /* ovl_cache_update_ino() sets is_whiteout on stale entry */ + /* ovl_cache_update() sets is_whiteout on stale entry */ if (!p->is_whiteout) { if (!dir_emit(ctx, p->name, p->len, p->ino, p->type)) break; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 0a42a25656fa..1a95ee237fa9 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -585,7 +585,7 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs) if (IS_ERR(whiteout)) goto cleanup_temp; - err = ovl_is_whiteout(whiteout); + err = ovl_upper_is_whiteout(ofs, whiteout); /* Best effort cleanup of whiteout and temp file */ if (err) diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index f8455fcb8b07..73ac47b49218 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -601,6 +601,16 @@ bool ovl_is_whiteout(struct dentry *dentry) return inode && IS_WHITEOUT(inode); } +/* + * Use this over ovl_is_whiteout for upper and lower files, as it also + * handles overlay.whiteout xattr whiteout files. + */ +bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path) +{ + return ovl_is_whiteout(path->dentry) || + ovl_path_check_xwhiteout_xattr(ofs, path); +} + struct file *ovl_path_open(const struct path *path, int flags) { struct inode *inode = d_inode(path->dentry); @@ -716,6 +726,32 @@ bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path) return false; } +bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path) +{ + struct dentry *dentry = path->dentry; + int res; + + /* xattr.whiteout must be a zero size regular file */ + if (!d_is_reg(dentry) || i_size_read(d_inode(dentry)) != 0) + return false; + + res = ovl_path_getxattr(ofs, path, OVL_XATTR_XWHITEOUT, NULL, 0); + return res >= 0; +} + +bool ovl_path_check_xwhiteouts_xattr(struct ovl_fs *ofs, const struct path *path) +{ + struct dentry *dentry = path->dentry; + int res; + + /* xattr.whiteouts must be a directory */ + if (!d_is_dir(dentry)) + return false; + + res = ovl_path_getxattr(ofs, path, OVL_XATTR_XWHITEOUTS, NULL, 0); + return res >= 0; +} + /* * Load persistent uuid from xattr into s_uuid if found, or store a new * random generated value in s_uuid and in xattr. @@ -800,6 +836,8 @@ bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, #define OVL_XATTR_UUID_POSTFIX "uuid" #define OVL_XATTR_METACOPY_POSTFIX "metacopy" #define OVL_XATTR_PROTATTR_POSTFIX "protattr" +#define OVL_XATTR_XWHITEOUT_POSTFIX "whiteout" +#define OVL_XATTR_XWHITEOUTS_POSTFIX "whiteouts" #define OVL_XATTR_TAB_ENTRY(x) \ [x] = { [false] = OVL_XATTR_TRUSTED_PREFIX x ## _POSTFIX, \ @@ -815,6 +853,8 @@ const char *const ovl_xattr_table[][2] = { OVL_XATTR_TAB_ENTRY(OVL_XATTR_UUID), OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY), OVL_XATTR_TAB_ENTRY(OVL_XATTR_PROTATTR), + OVL_XATTR_TAB_ENTRY(OVL_XATTR_XWHITEOUT), + OVL_XATTR_TAB_ENTRY(OVL_XATTR_XWHITEOUTS), }; int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,