1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2bbb1e54dSMiklos Szeredi /* 3bbb1e54dSMiklos Szeredi * Copyright (C) 2011 Novell Inc. 4bbb1e54dSMiklos Szeredi * Copyright (C) 2016 Red Hat, Inc. 5bbb1e54dSMiklos Szeredi */ 6bbb1e54dSMiklos Szeredi 7bbb1e54dSMiklos Szeredi #include <linux/fs.h> 8bbb1e54dSMiklos Szeredi #include <linux/mount.h> 9bbb1e54dSMiklos Szeredi #include <linux/slab.h> 105b825c3aSIngo Molnar #include <linux/cred.h> 11bbb1e54dSMiklos Szeredi #include <linux/xattr.h> 1202bcd157SAmir Goldstein #include <linux/exportfs.h> 13096a218aSAmir Goldstein #include <linux/fileattr.h> 1402bcd157SAmir Goldstein #include <linux/uuid.h> 15caf70cb2SAmir Goldstein #include <linux/namei.h> 16caf70cb2SAmir Goldstein #include <linux/ratelimit.h> 17bbb1e54dSMiklos Szeredi #include "overlayfs.h" 18bbb1e54dSMiklos Szeredi 19bbb1e54dSMiklos Szeredi int ovl_want_write(struct dentry *dentry) 20bbb1e54dSMiklos Szeredi { 21bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 2208f4c7c8SMiklos Szeredi return mnt_want_write(ovl_upper_mnt(ofs)); 23bbb1e54dSMiklos Szeredi } 24bbb1e54dSMiklos Szeredi 25bbb1e54dSMiklos Szeredi void ovl_drop_write(struct dentry *dentry) 26bbb1e54dSMiklos Szeredi { 27bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 2808f4c7c8SMiklos Szeredi mnt_drop_write(ovl_upper_mnt(ofs)); 29bbb1e54dSMiklos Szeredi } 30bbb1e54dSMiklos Szeredi 31bbb1e54dSMiklos Szeredi struct dentry *ovl_workdir(struct dentry *dentry) 32bbb1e54dSMiklos Szeredi { 33bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 34bbb1e54dSMiklos Szeredi return ofs->workdir; 35bbb1e54dSMiklos Szeredi } 36bbb1e54dSMiklos Szeredi 37bbb1e54dSMiklos Szeredi const struct cred *ovl_override_creds(struct super_block *sb) 38bbb1e54dSMiklos Szeredi { 39bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = sb->s_fs_info; 40bbb1e54dSMiklos Szeredi 41bbb1e54dSMiklos Szeredi return override_creds(ofs->creator_cred); 42bbb1e54dSMiklos Szeredi } 43bbb1e54dSMiklos Szeredi 44e487d889SAmir Goldstein /* 45e487d889SAmir Goldstein * Check if underlying fs supports file handles and try to determine encoding 46e487d889SAmir Goldstein * type, in order to deduce maximum inode number used by fs. 47e487d889SAmir Goldstein * 48e487d889SAmir Goldstein * Return 0 if file handles are not supported. 49e487d889SAmir Goldstein * Return 1 (FILEID_INO32_GEN) if fs uses the default 32bit inode encoding. 50e487d889SAmir Goldstein * Return -1 if fs uses a non default encoding with unknown inode size. 51e487d889SAmir Goldstein */ 52e487d889SAmir Goldstein int ovl_can_decode_fh(struct super_block *sb) 5302bcd157SAmir Goldstein { 54c846af05SMiklos Szeredi if (!capable(CAP_DAC_READ_SEARCH)) 55c846af05SMiklos Szeredi return 0; 56c846af05SMiklos Szeredi 579df085f3SAmir Goldstein if (!sb->s_export_op || !sb->s_export_op->fh_to_dentry) 58e487d889SAmir Goldstein return 0; 59e487d889SAmir Goldstein 60e487d889SAmir Goldstein return sb->s_export_op->encode_fh ? -1 : FILEID_INO32_GEN; 6102bcd157SAmir Goldstein } 6202bcd157SAmir Goldstein 6302bcd157SAmir Goldstein struct dentry *ovl_indexdir(struct super_block *sb) 6402bcd157SAmir Goldstein { 6502bcd157SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 6602bcd157SAmir Goldstein 6702bcd157SAmir Goldstein return ofs->indexdir; 6802bcd157SAmir Goldstein } 6902bcd157SAmir Goldstein 70f168f109SAmir Goldstein /* Index all files on copy up. For now only enabled for NFS export */ 71f168f109SAmir Goldstein bool ovl_index_all(struct super_block *sb) 72f168f109SAmir Goldstein { 73f168f109SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 74f168f109SAmir Goldstein 75f168f109SAmir Goldstein return ofs->config.nfs_export && ofs->config.index; 76f168f109SAmir Goldstein } 77f168f109SAmir Goldstein 78f168f109SAmir Goldstein /* Verify lower origin on lookup. For now only enabled for NFS export */ 79f168f109SAmir Goldstein bool ovl_verify_lower(struct super_block *sb) 80f168f109SAmir Goldstein { 81f168f109SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 82f168f109SAmir Goldstein 83f168f109SAmir Goldstein return ofs->config.nfs_export && ofs->config.index; 84f168f109SAmir Goldstein } 85f168f109SAmir Goldstein 86bbb1e54dSMiklos Szeredi struct ovl_entry *ovl_alloc_entry(unsigned int numlower) 87bbb1e54dSMiklos Szeredi { 88bbb1e54dSMiklos Szeredi size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); 89bbb1e54dSMiklos Szeredi struct ovl_entry *oe = kzalloc(size, GFP_KERNEL); 90bbb1e54dSMiklos Szeredi 91bbb1e54dSMiklos Szeredi if (oe) 92bbb1e54dSMiklos Szeredi oe->numlower = numlower; 93bbb1e54dSMiklos Szeredi 94bbb1e54dSMiklos Szeredi return oe; 95bbb1e54dSMiklos Szeredi } 96bbb1e54dSMiklos Szeredi 97bbb1e54dSMiklos Szeredi bool ovl_dentry_remote(struct dentry *dentry) 98bbb1e54dSMiklos Szeredi { 99bbb1e54dSMiklos Szeredi return dentry->d_flags & 1007925dad8SMiklos Szeredi (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); 101bbb1e54dSMiklos Szeredi } 102bbb1e54dSMiklos Szeredi 103f4288844SMiklos Szeredi void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, 104f4288844SMiklos Szeredi unsigned int mask) 105f4288844SMiklos Szeredi { 106f4288844SMiklos Szeredi struct ovl_entry *oe = OVL_E(dentry); 107f4288844SMiklos Szeredi unsigned int i, flags = 0; 108f4288844SMiklos Szeredi 109bccece1eSMiklos Szeredi if (upperdentry) 110bccece1eSMiklos Szeredi flags |= upperdentry->d_flags; 111f4288844SMiklos Szeredi for (i = 0; i < oe->numlower; i++) 112f4288844SMiklos Szeredi flags |= oe->lowerstack[i].dentry->d_flags; 113f4288844SMiklos Szeredi 114f4288844SMiklos Szeredi spin_lock(&dentry->d_lock); 115f4288844SMiklos Szeredi dentry->d_flags &= ~mask; 116f4288844SMiklos Szeredi dentry->d_flags |= flags & mask; 117f4288844SMiklos Szeredi spin_unlock(&dentry->d_lock); 118f4288844SMiklos Szeredi } 119f4288844SMiklos Szeredi 120bbb1e54dSMiklos Szeredi bool ovl_dentry_weird(struct dentry *dentry) 121bbb1e54dSMiklos Szeredi { 122bbb1e54dSMiklos Szeredi return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT | 123bbb1e54dSMiklos Szeredi DCACHE_MANAGE_TRANSIT | 124bbb1e54dSMiklos Szeredi DCACHE_OP_HASH | 125bbb1e54dSMiklos Szeredi DCACHE_OP_COMPARE); 126bbb1e54dSMiklos Szeredi } 127bbb1e54dSMiklos Szeredi 128bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_type(struct dentry *dentry) 129bbb1e54dSMiklos Szeredi { 130bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 131bbb1e54dSMiklos Szeredi enum ovl_path_type type = 0; 132bbb1e54dSMiklos Szeredi 13309d8b586SMiklos Szeredi if (ovl_dentry_upper(dentry)) { 134bbb1e54dSMiklos Szeredi type = __OVL_PATH_UPPER; 135bbb1e54dSMiklos Szeredi 136bbb1e54dSMiklos Szeredi /* 13759548503SAmir Goldstein * Non-dir dentry can hold lower dentry of its copy up origin. 138bbb1e54dSMiklos Szeredi */ 13959548503SAmir Goldstein if (oe->numlower) { 14060124877SVivek Goyal if (ovl_test_flag(OVL_CONST_INO, d_inode(dentry))) 14159548503SAmir Goldstein type |= __OVL_PATH_ORIGIN; 1420b17c28aSVivek Goyal if (d_is_dir(dentry) || 1430b17c28aSVivek Goyal !ovl_has_upperdata(d_inode(dentry))) 144bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 14559548503SAmir Goldstein } 146bbb1e54dSMiklos Szeredi } else { 147bbb1e54dSMiklos Szeredi if (oe->numlower > 1) 148bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 149bbb1e54dSMiklos Szeredi } 150bbb1e54dSMiklos Szeredi return type; 151bbb1e54dSMiklos Szeredi } 152bbb1e54dSMiklos Szeredi 153bbb1e54dSMiklos Szeredi void ovl_path_upper(struct dentry *dentry, struct path *path) 154bbb1e54dSMiklos Szeredi { 155bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 156bbb1e54dSMiklos Szeredi 15708f4c7c8SMiklos Szeredi path->mnt = ovl_upper_mnt(ofs); 15809d8b586SMiklos Szeredi path->dentry = ovl_dentry_upper(dentry); 159bbb1e54dSMiklos Szeredi } 160bbb1e54dSMiklos Szeredi 161bbb1e54dSMiklos Szeredi void ovl_path_lower(struct dentry *dentry, struct path *path) 162bbb1e54dSMiklos Szeredi { 163bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 164bbb1e54dSMiklos Szeredi 165b9343632SChandan Rajendra if (oe->numlower) { 166b9343632SChandan Rajendra path->mnt = oe->lowerstack[0].layer->mnt; 167b9343632SChandan Rajendra path->dentry = oe->lowerstack[0].dentry; 168b9343632SChandan Rajendra } else { 169b9343632SChandan Rajendra *path = (struct path) { }; 170b9343632SChandan Rajendra } 171bbb1e54dSMiklos Szeredi } 172bbb1e54dSMiklos Szeredi 1734f93b426SVivek Goyal void ovl_path_lowerdata(struct dentry *dentry, struct path *path) 1744f93b426SVivek Goyal { 1754f93b426SVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 1764f93b426SVivek Goyal 1774f93b426SVivek Goyal if (oe->numlower) { 1784f93b426SVivek Goyal path->mnt = oe->lowerstack[oe->numlower - 1].layer->mnt; 1794f93b426SVivek Goyal path->dentry = oe->lowerstack[oe->numlower - 1].dentry; 1804f93b426SVivek Goyal } else { 1814f93b426SVivek Goyal *path = (struct path) { }; 1824f93b426SVivek Goyal } 1834f93b426SVivek Goyal } 1844f93b426SVivek Goyal 185bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) 186bbb1e54dSMiklos Szeredi { 187bbb1e54dSMiklos Szeredi enum ovl_path_type type = ovl_path_type(dentry); 188bbb1e54dSMiklos Szeredi 189bbb1e54dSMiklos Szeredi if (!OVL_TYPE_UPPER(type)) 190bbb1e54dSMiklos Szeredi ovl_path_lower(dentry, path); 191bbb1e54dSMiklos Szeredi else 192bbb1e54dSMiklos Szeredi ovl_path_upper(dentry, path); 193bbb1e54dSMiklos Szeredi 194bbb1e54dSMiklos Szeredi return type; 195bbb1e54dSMiklos Szeredi } 196bbb1e54dSMiklos Szeredi 1971248ea4bSAmir Goldstein enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path) 1981248ea4bSAmir Goldstein { 1991248ea4bSAmir Goldstein enum ovl_path_type type = ovl_path_type(dentry); 2001248ea4bSAmir Goldstein 2011248ea4bSAmir Goldstein WARN_ON_ONCE(d_is_dir(dentry)); 2021248ea4bSAmir Goldstein 2031248ea4bSAmir Goldstein if (!OVL_TYPE_UPPER(type) || OVL_TYPE_MERGE(type)) 2041248ea4bSAmir Goldstein ovl_path_lowerdata(dentry, path); 2051248ea4bSAmir Goldstein else 2061248ea4bSAmir Goldstein ovl_path_upper(dentry, path); 2071248ea4bSAmir Goldstein 2081248ea4bSAmir Goldstein return type; 2091248ea4bSAmir Goldstein } 2101248ea4bSAmir Goldstein 211bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_upper(struct dentry *dentry) 212bbb1e54dSMiklos Szeredi { 21309d8b586SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(d_inode(dentry))); 214bbb1e54dSMiklos Szeredi } 215bbb1e54dSMiklos Szeredi 216bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_lower(struct dentry *dentry) 217bbb1e54dSMiklos Szeredi { 218bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 219bbb1e54dSMiklos Szeredi 22009d8b586SMiklos Szeredi return oe->numlower ? oe->lowerstack[0].dentry : NULL; 221bbb1e54dSMiklos Szeredi } 222bbb1e54dSMiklos Szeredi 22313464165SMiklos Szeredi const struct ovl_layer *ovl_layer_lower(struct dentry *dentry) 224da309e8cSAmir Goldstein { 225da309e8cSAmir Goldstein struct ovl_entry *oe = dentry->d_fsdata; 226da309e8cSAmir Goldstein 227da309e8cSAmir Goldstein return oe->numlower ? oe->lowerstack[0].layer : NULL; 228da309e8cSAmir Goldstein } 229da309e8cSAmir Goldstein 230647d253fSVivek Goyal /* 231647d253fSVivek Goyal * ovl_dentry_lower() could return either a data dentry or metacopy dentry 232597534e7SXiong Zhenwu * depending on what is stored in lowerstack[0]. At times we need to find 233647d253fSVivek Goyal * lower dentry which has data (and not metacopy dentry). This helper 234647d253fSVivek Goyal * returns the lower data dentry. 235647d253fSVivek Goyal */ 236647d253fSVivek Goyal struct dentry *ovl_dentry_lowerdata(struct dentry *dentry) 237647d253fSVivek Goyal { 238647d253fSVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 239647d253fSVivek Goyal 240647d253fSVivek Goyal return oe->numlower ? oe->lowerstack[oe->numlower - 1].dentry : NULL; 241647d253fSVivek Goyal } 242647d253fSVivek Goyal 243bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_real(struct dentry *dentry) 244bbb1e54dSMiklos Szeredi { 24509d8b586SMiklos Szeredi return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry); 246bbb1e54dSMiklos Szeredi } 247bbb1e54dSMiklos Szeredi 2481d88f183SMiklos Szeredi struct dentry *ovl_i_dentry_upper(struct inode *inode) 2491d88f183SMiklos Szeredi { 2501d88f183SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(inode)); 2511d88f183SMiklos Szeredi } 2521d88f183SMiklos Szeredi 253ffa5723cSAmir Goldstein void ovl_i_path_real(struct inode *inode, struct path *path) 254ffa5723cSAmir Goldstein { 255ffa5723cSAmir Goldstein path->dentry = ovl_i_dentry_upper(inode); 256ffa5723cSAmir Goldstein if (!path->dentry) { 257ffa5723cSAmir Goldstein path->dentry = OVL_I(inode)->lowerpath.dentry; 258ffa5723cSAmir Goldstein path->mnt = OVL_I(inode)->lowerpath.layer->mnt; 259ffa5723cSAmir Goldstein } else { 260ffa5723cSAmir Goldstein path->mnt = ovl_upper_mnt(OVL_FS(inode->i_sb)); 261ffa5723cSAmir Goldstein } 262ffa5723cSAmir Goldstein } 263ffa5723cSAmir Goldstein 26409d8b586SMiklos Szeredi struct inode *ovl_inode_upper(struct inode *inode) 26525b7713aSMiklos Szeredi { 2661d88f183SMiklos Szeredi struct dentry *upperdentry = ovl_i_dentry_upper(inode); 26725b7713aSMiklos Szeredi 26809d8b586SMiklos Szeredi return upperdentry ? d_inode(upperdentry) : NULL; 26925b7713aSMiklos Szeredi } 27025b7713aSMiklos Szeredi 27109d8b586SMiklos Szeredi struct inode *ovl_inode_lower(struct inode *inode) 27209d8b586SMiklos Szeredi { 273ffa5723cSAmir Goldstein struct dentry *lowerdentry = OVL_I(inode)->lowerpath.dentry; 274ffa5723cSAmir Goldstein 275ffa5723cSAmir Goldstein return lowerdentry ? d_inode(lowerdentry) : NULL; 27609d8b586SMiklos Szeredi } 27709d8b586SMiklos Szeredi 27809d8b586SMiklos Szeredi struct inode *ovl_inode_real(struct inode *inode) 27909d8b586SMiklos Szeredi { 28009d8b586SMiklos Szeredi return ovl_inode_upper(inode) ?: ovl_inode_lower(inode); 28109d8b586SMiklos Szeredi } 28209d8b586SMiklos Szeredi 2832664bd08SVivek Goyal /* Return inode which contains lower data. Do not return metacopy */ 2842664bd08SVivek Goyal struct inode *ovl_inode_lowerdata(struct inode *inode) 2852664bd08SVivek Goyal { 2862664bd08SVivek Goyal if (WARN_ON(!S_ISREG(inode->i_mode))) 2872664bd08SVivek Goyal return NULL; 2882664bd08SVivek Goyal 2892664bd08SVivek Goyal return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode); 2902664bd08SVivek Goyal } 29109d8b586SMiklos Szeredi 2924823d49cSVivek Goyal /* Return real inode which contains data. Does not return metacopy inode */ 2934823d49cSVivek Goyal struct inode *ovl_inode_realdata(struct inode *inode) 2944823d49cSVivek Goyal { 2954823d49cSVivek Goyal struct inode *upperinode; 2964823d49cSVivek Goyal 2974823d49cSVivek Goyal upperinode = ovl_inode_upper(inode); 2984823d49cSVivek Goyal if (upperinode && ovl_has_upperdata(inode)) 2994823d49cSVivek Goyal return upperinode; 3004823d49cSVivek Goyal 3014823d49cSVivek Goyal return ovl_inode_lowerdata(inode); 3024823d49cSVivek Goyal } 3034823d49cSVivek Goyal 3044edb83bbSMiklos Szeredi struct ovl_dir_cache *ovl_dir_cache(struct inode *inode) 305bbb1e54dSMiklos Szeredi { 3064edb83bbSMiklos Szeredi return OVL_I(inode)->cache; 307bbb1e54dSMiklos Szeredi } 308bbb1e54dSMiklos Szeredi 3094edb83bbSMiklos Szeredi void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache) 310bbb1e54dSMiklos Szeredi { 3114edb83bbSMiklos Szeredi OVL_I(inode)->cache = cache; 312bbb1e54dSMiklos Szeredi } 313bbb1e54dSMiklos Szeredi 314c62520a8SAmir Goldstein void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry) 315c62520a8SAmir Goldstein { 316c62520a8SAmir Goldstein set_bit(flag, &OVL_E(dentry)->flags); 317c62520a8SAmir Goldstein } 318c62520a8SAmir Goldstein 319c62520a8SAmir Goldstein void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry) 320c62520a8SAmir Goldstein { 321c62520a8SAmir Goldstein clear_bit(flag, &OVL_E(dentry)->flags); 322c62520a8SAmir Goldstein } 323c62520a8SAmir Goldstein 324c62520a8SAmir Goldstein bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry) 325c62520a8SAmir Goldstein { 326c62520a8SAmir Goldstein return test_bit(flag, &OVL_E(dentry)->flags); 327c62520a8SAmir Goldstein } 328c62520a8SAmir Goldstein 329bbb1e54dSMiklos Szeredi bool ovl_dentry_is_opaque(struct dentry *dentry) 330bbb1e54dSMiklos Szeredi { 331c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_OPAQUE, dentry); 332bbb1e54dSMiklos Szeredi } 333bbb1e54dSMiklos Szeredi 334bbb1e54dSMiklos Szeredi bool ovl_dentry_is_whiteout(struct dentry *dentry) 335bbb1e54dSMiklos Szeredi { 336bbb1e54dSMiklos Szeredi return !dentry->d_inode && ovl_dentry_is_opaque(dentry); 337bbb1e54dSMiklos Szeredi } 338bbb1e54dSMiklos Szeredi 3395cf5b477SMiklos Szeredi void ovl_dentry_set_opaque(struct dentry *dentry) 340bbb1e54dSMiklos Szeredi { 341c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_OPAQUE, dentry); 342bbb1e54dSMiklos Szeredi } 343bbb1e54dSMiklos Szeredi 34455acc661SMiklos Szeredi /* 345aa3ff3c1SAmir Goldstein * For hard links and decoded file handles, it's possible for ovl_dentry_upper() 346aa3ff3c1SAmir Goldstein * to return positive, while there's no actual upper alias for the inode. 347aa3ff3c1SAmir Goldstein * Copy up code needs to know about the existence of the upper alias, so it 348aa3ff3c1SAmir Goldstein * can't use ovl_dentry_upper(). 34955acc661SMiklos Szeredi */ 35055acc661SMiklos Szeredi bool ovl_dentry_has_upper_alias(struct dentry *dentry) 35155acc661SMiklos Szeredi { 352c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_UPPER_ALIAS, dentry); 35355acc661SMiklos Szeredi } 35455acc661SMiklos Szeredi 35555acc661SMiklos Szeredi void ovl_dentry_set_upper_alias(struct dentry *dentry) 35655acc661SMiklos Szeredi { 357c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_UPPER_ALIAS, dentry); 35855acc661SMiklos Szeredi } 35955acc661SMiklos Szeredi 3600c288874SVivek Goyal static bool ovl_should_check_upperdata(struct inode *inode) 3610c288874SVivek Goyal { 3620c288874SVivek Goyal if (!S_ISREG(inode->i_mode)) 3630c288874SVivek Goyal return false; 3640c288874SVivek Goyal 3650c288874SVivek Goyal if (!ovl_inode_lower(inode)) 3660c288874SVivek Goyal return false; 3670c288874SVivek Goyal 3680c288874SVivek Goyal return true; 3690c288874SVivek Goyal } 3700c288874SVivek Goyal 3710c288874SVivek Goyal bool ovl_has_upperdata(struct inode *inode) 3720c288874SVivek Goyal { 3730c288874SVivek Goyal if (!ovl_should_check_upperdata(inode)) 3740c288874SVivek Goyal return true; 3750c288874SVivek Goyal 3760c288874SVivek Goyal if (!ovl_test_flag(OVL_UPPERDATA, inode)) 3770c288874SVivek Goyal return false; 3780c288874SVivek Goyal /* 3790c288874SVivek Goyal * Pairs with smp_wmb() in ovl_set_upperdata(). Main user of 3800c288874SVivek Goyal * ovl_has_upperdata() is ovl_copy_up_meta_inode_data(). Make sure 3810c288874SVivek Goyal * if setting of OVL_UPPERDATA is visible, then effects of writes 3820c288874SVivek Goyal * before that are visible too. 3830c288874SVivek Goyal */ 3840c288874SVivek Goyal smp_rmb(); 3850c288874SVivek Goyal return true; 3860c288874SVivek Goyal } 3870c288874SVivek Goyal 3880c288874SVivek Goyal void ovl_set_upperdata(struct inode *inode) 3890c288874SVivek Goyal { 3900c288874SVivek Goyal /* 3910c288874SVivek Goyal * Pairs with smp_rmb() in ovl_has_upperdata(). Make sure 3920c288874SVivek Goyal * if OVL_UPPERDATA flag is visible, then effects of write operations 3930c288874SVivek Goyal * before it are visible as well. 3940c288874SVivek Goyal */ 3950c288874SVivek Goyal smp_wmb(); 3960c288874SVivek Goyal ovl_set_flag(OVL_UPPERDATA, inode); 3970c288874SVivek Goyal } 3980c288874SVivek Goyal 3990c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 4000c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags) 4010c288874SVivek Goyal { 4020c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 4030c288874SVivek Goyal return false; 4040c288874SVivek Goyal 4050c288874SVivek Goyal return !ovl_test_flag(OVL_UPPERDATA, d_inode(dentry)); 4060c288874SVivek Goyal } 4070c288874SVivek Goyal 4080c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags) 4090c288874SVivek Goyal { 4100c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 4110c288874SVivek Goyal return false; 4120c288874SVivek Goyal 4130c288874SVivek Goyal return !ovl_has_upperdata(d_inode(dentry)); 4140c288874SVivek Goyal } 4150c288874SVivek Goyal 416a6c60655SMiklos Szeredi bool ovl_redirect_dir(struct super_block *sb) 417a6c60655SMiklos Szeredi { 418a6c60655SMiklos Szeredi struct ovl_fs *ofs = sb->s_fs_info; 419a6c60655SMiklos Szeredi 42021a22878SAmir Goldstein return ofs->config.redirect_dir && !ofs->noxattr; 421a6c60655SMiklos Szeredi } 422a6c60655SMiklos Szeredi 423a6c60655SMiklos Szeredi const char *ovl_dentry_get_redirect(struct dentry *dentry) 424a6c60655SMiklos Szeredi { 425cf31c463SMiklos Szeredi return OVL_I(d_inode(dentry))->redirect; 426a6c60655SMiklos Szeredi } 427a6c60655SMiklos Szeredi 428a6c60655SMiklos Szeredi void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect) 429a6c60655SMiklos Szeredi { 430cf31c463SMiklos Szeredi struct ovl_inode *oi = OVL_I(d_inode(dentry)); 431a6c60655SMiklos Szeredi 432cf31c463SMiklos Szeredi kfree(oi->redirect); 433cf31c463SMiklos Szeredi oi->redirect = redirect; 434a6c60655SMiklos Szeredi } 435a6c60655SMiklos Szeredi 43609d8b586SMiklos Szeredi void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) 437bbb1e54dSMiklos Szeredi { 43809d8b586SMiklos Szeredi struct inode *upperinode = d_inode(upperdentry); 439e6d2ebddSMiklos Szeredi 44009d8b586SMiklos Szeredi WARN_ON(OVL_I(inode)->__upperdentry); 44109d8b586SMiklos Szeredi 44225b7713aSMiklos Szeredi /* 44309d8b586SMiklos Szeredi * Make sure upperdentry is consistent before making it visible 44425b7713aSMiklos Szeredi */ 44525b7713aSMiklos Szeredi smp_wmb(); 44609d8b586SMiklos Szeredi OVL_I(inode)->__upperdentry = upperdentry; 44731747edaSAmir Goldstein if (inode_unhashed(inode)) { 44825b7713aSMiklos Szeredi inode->i_private = upperinode; 449bbb1e54dSMiklos Szeredi __insert_inode_hash(inode, (unsigned long) upperinode); 450bbb1e54dSMiklos Szeredi } 45125b7713aSMiklos Szeredi } 452bbb1e54dSMiklos Szeredi 45365cd913eSAmir Goldstein static void ovl_dir_version_inc(struct dentry *dentry, bool impurity) 454bbb1e54dSMiklos Szeredi { 45504a01ac7SMiklos Szeredi struct inode *inode = d_inode(dentry); 456bbb1e54dSMiklos Szeredi 45704a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 45865cd913eSAmir Goldstein WARN_ON(!d_is_dir(dentry)); 4594edb83bbSMiklos Szeredi /* 46065cd913eSAmir Goldstein * Version is used by readdir code to keep cache consistent. 46165cd913eSAmir Goldstein * For merge dirs (or dirs with origin) all changes need to be noted. 46265cd913eSAmir Goldstein * For non-merge dirs, cache contains only impure entries (i.e. ones 46365cd913eSAmir Goldstein * which have been copied up and have origins), so only need to note 46465cd913eSAmir Goldstein * changes to impure entries. 4654edb83bbSMiklos Szeredi */ 46665cd913eSAmir Goldstein if (!ovl_dir_is_real(dentry) || impurity) 46704a01ac7SMiklos Szeredi OVL_I(inode)->version++; 468bbb1e54dSMiklos Szeredi } 469bbb1e54dSMiklos Szeredi 470d9854c87SMiklos Szeredi void ovl_dir_modified(struct dentry *dentry, bool impurity) 471d9854c87SMiklos Szeredi { 472d9854c87SMiklos Szeredi /* Copy mtime/ctime */ 4732878dffcSChristian Brauner ovl_copyattr(d_inode(dentry)); 474d9854c87SMiklos Szeredi 47565cd913eSAmir Goldstein ovl_dir_version_inc(dentry, impurity); 476d9854c87SMiklos Szeredi } 477d9854c87SMiklos Szeredi 478bbb1e54dSMiklos Szeredi u64 ovl_dentry_version_get(struct dentry *dentry) 479bbb1e54dSMiklos Szeredi { 48004a01ac7SMiklos Szeredi struct inode *inode = d_inode(dentry); 481bbb1e54dSMiklos Szeredi 48204a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 48304a01ac7SMiklos Szeredi return OVL_I(inode)->version; 484bbb1e54dSMiklos Szeredi } 485bbb1e54dSMiklos Szeredi 486bbb1e54dSMiklos Szeredi bool ovl_is_whiteout(struct dentry *dentry) 487bbb1e54dSMiklos Szeredi { 488bbb1e54dSMiklos Szeredi struct inode *inode = dentry->d_inode; 489bbb1e54dSMiklos Szeredi 490bbb1e54dSMiklos Szeredi return inode && IS_WHITEOUT(inode); 491bbb1e54dSMiklos Szeredi } 492bbb1e54dSMiklos Szeredi 4932d343087SAl Viro struct file *ovl_path_open(const struct path *path, int flags) 494bbb1e54dSMiklos Szeredi { 49556230d95SMiklos Szeredi struct inode *inode = d_inode(path->dentry); 4968423b3bdSChristian Brauner struct user_namespace *real_mnt_userns = mnt_user_ns(path->mnt); 49756230d95SMiklos Szeredi int err, acc_mode; 49856230d95SMiklos Szeredi 49956230d95SMiklos Szeredi if (flags & ~(O_ACCMODE | O_LARGEFILE)) 50056230d95SMiklos Szeredi BUG(); 50156230d95SMiklos Szeredi 50256230d95SMiklos Szeredi switch (flags & O_ACCMODE) { 50356230d95SMiklos Szeredi case O_RDONLY: 50456230d95SMiklos Szeredi acc_mode = MAY_READ; 50556230d95SMiklos Szeredi break; 50656230d95SMiklos Szeredi case O_WRONLY: 50756230d95SMiklos Szeredi acc_mode = MAY_WRITE; 50856230d95SMiklos Szeredi break; 50956230d95SMiklos Szeredi default: 51056230d95SMiklos Szeredi BUG(); 51156230d95SMiklos Szeredi } 51256230d95SMiklos Szeredi 5138423b3bdSChristian Brauner err = inode_permission(real_mnt_userns, inode, acc_mode | MAY_OPEN); 51456230d95SMiklos Szeredi if (err) 51556230d95SMiklos Szeredi return ERR_PTR(err); 51656230d95SMiklos Szeredi 51756230d95SMiklos Szeredi /* O_NOATIME is an optimization, don't fail if not permitted */ 5188423b3bdSChristian Brauner if (inode_owner_or_capable(real_mnt_userns, inode)) 51956230d95SMiklos Szeredi flags |= O_NOATIME; 52056230d95SMiklos Szeredi 52156230d95SMiklos Szeredi return dentry_open(path, flags, current_cred()); 522bbb1e54dSMiklos Szeredi } 52339d3d60aSAmir Goldstein 5240c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 5250c288874SVivek Goyal static bool ovl_already_copied_up_locked(struct dentry *dentry, int flags) 5260c288874SVivek Goyal { 5270c288874SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 5280c288874SVivek Goyal 5290c288874SVivek Goyal if (ovl_dentry_upper(dentry) && 5300c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 5310c288874SVivek Goyal !ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 5320c288874SVivek Goyal return true; 5330c288874SVivek Goyal 5340c288874SVivek Goyal return false; 5350c288874SVivek Goyal } 5360c288874SVivek Goyal 5370c288874SVivek Goyal bool ovl_already_copied_up(struct dentry *dentry, int flags) 5382002df85SVivek Goyal { 5392002df85SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 5402002df85SVivek Goyal 5412002df85SVivek Goyal /* 5422002df85SVivek Goyal * Check if copy-up has happened as well as for upper alias (in 5432002df85SVivek Goyal * case of hard links) is there. 5442002df85SVivek Goyal * 5452002df85SVivek Goyal * Both checks are lockless: 5462002df85SVivek Goyal * - false negatives: will recheck under oi->lock 5472002df85SVivek Goyal * - false positives: 5482002df85SVivek Goyal * + ovl_dentry_upper() uses memory barriers to ensure the 5492002df85SVivek Goyal * upper dentry is up-to-date 5502002df85SVivek Goyal * + ovl_dentry_has_upper_alias() relies on locking of 5512002df85SVivek Goyal * upper parent i_rwsem to prevent reordering copy-up 5522002df85SVivek Goyal * with rename. 5532002df85SVivek Goyal */ 5542002df85SVivek Goyal if (ovl_dentry_upper(dentry) && 5550c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 5560c288874SVivek Goyal !ovl_dentry_needs_data_copy_up(dentry, flags)) 5572002df85SVivek Goyal return true; 5582002df85SVivek Goyal 5592002df85SVivek Goyal return false; 5602002df85SVivek Goyal } 5612002df85SVivek Goyal 5620c288874SVivek Goyal int ovl_copy_up_start(struct dentry *dentry, int flags) 56339d3d60aSAmir Goldstein { 5641e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 56539d3d60aSAmir Goldstein int err; 56639d3d60aSAmir Goldstein 567531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 5680c288874SVivek Goyal if (!err && ovl_already_copied_up_locked(dentry, flags)) { 56939d3d60aSAmir Goldstein err = 1; /* Already copied up */ 5701e92e307SAmir Goldstein ovl_inode_unlock(inode); 57139d3d60aSAmir Goldstein } 57239d3d60aSAmir Goldstein 57339d3d60aSAmir Goldstein return err; 57439d3d60aSAmir Goldstein } 57539d3d60aSAmir Goldstein 57639d3d60aSAmir Goldstein void ovl_copy_up_end(struct dentry *dentry) 57739d3d60aSAmir Goldstein { 5781e92e307SAmir Goldstein ovl_inode_unlock(d_inode(dentry)); 57939d3d60aSAmir Goldstein } 58082b749b2SAmir Goldstein 5812d343087SAl Viro bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path) 582b79e05aaSAmir Goldstein { 583b79e05aaSAmir Goldstein int res; 584b79e05aaSAmir Goldstein 585dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_ORIGIN, NULL, 0); 586b79e05aaSAmir Goldstein 587b79e05aaSAmir Goldstein /* Zero size value means "copied up but origin unknown" */ 588b79e05aaSAmir Goldstein if (res >= 0) 589b79e05aaSAmir Goldstein return true; 590b79e05aaSAmir Goldstein 591b79e05aaSAmir Goldstein return false; 592b79e05aaSAmir Goldstein } 593b79e05aaSAmir Goldstein 5942d343087SAl Viro bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, 59543d193f8SMiklos Szeredi enum ovl_xattr ox) 596f3a15685SAmir Goldstein { 597f3a15685SAmir Goldstein int res; 598f3a15685SAmir Goldstein char val; 599f3a15685SAmir Goldstein 600dad7017aSChristian Brauner if (!d_is_dir(path->dentry)) 601f3a15685SAmir Goldstein return false; 602f3a15685SAmir Goldstein 603dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, ox, &val, 1); 604f3a15685SAmir Goldstein if (res == 1 && val == 'y') 605f3a15685SAmir Goldstein return true; 606f3a15685SAmir Goldstein 607f3a15685SAmir Goldstein return false; 608f3a15685SAmir Goldstein } 609f3a15685SAmir Goldstein 61043d193f8SMiklos Szeredi #define OVL_XATTR_OPAQUE_POSTFIX "opaque" 61143d193f8SMiklos Szeredi #define OVL_XATTR_REDIRECT_POSTFIX "redirect" 61243d193f8SMiklos Szeredi #define OVL_XATTR_ORIGIN_POSTFIX "origin" 61343d193f8SMiklos Szeredi #define OVL_XATTR_IMPURE_POSTFIX "impure" 61443d193f8SMiklos Szeredi #define OVL_XATTR_NLINK_POSTFIX "nlink" 61543d193f8SMiklos Szeredi #define OVL_XATTR_UPPER_POSTFIX "upper" 61643d193f8SMiklos Szeredi #define OVL_XATTR_METACOPY_POSTFIX "metacopy" 617096a218aSAmir Goldstein #define OVL_XATTR_PROTATTR_POSTFIX "protattr" 61843d193f8SMiklos Szeredi 61943d193f8SMiklos Szeredi #define OVL_XATTR_TAB_ENTRY(x) \ 6202d2f2d73SMiklos Szeredi [x] = { [false] = OVL_XATTR_TRUSTED_PREFIX x ## _POSTFIX, \ 6212d2f2d73SMiklos Szeredi [true] = OVL_XATTR_USER_PREFIX x ## _POSTFIX } 62243d193f8SMiklos Szeredi 6232d2f2d73SMiklos Szeredi const char *const ovl_xattr_table[][2] = { 62443d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_OPAQUE), 62543d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_REDIRECT), 62643d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_ORIGIN), 62743d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_IMPURE), 62843d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_NLINK), 62943d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_UPPER), 63043d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY), 631096a218aSAmir Goldstein OVL_XATTR_TAB_ENTRY(OVL_XATTR_PROTATTR), 63243d193f8SMiklos Szeredi }; 63343d193f8SMiklos Szeredi 634a0c236b1SAmir Goldstein int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 63543d193f8SMiklos Szeredi enum ovl_xattr ox, const void *value, size_t size, 63682b749b2SAmir Goldstein int xerr) 63782b749b2SAmir Goldstein { 63882b749b2SAmir Goldstein int err; 63982b749b2SAmir Goldstein 64082b749b2SAmir Goldstein if (ofs->noxattr) 64182b749b2SAmir Goldstein return xerr; 64282b749b2SAmir Goldstein 643c914c0e2SAmir Goldstein err = ovl_setxattr(ofs, upperdentry, ox, value, size); 64482b749b2SAmir Goldstein 64582b749b2SAmir Goldstein if (err == -EOPNOTSUPP) { 64643d193f8SMiklos Szeredi pr_warn("cannot set %s xattr on upper\n", ovl_xattr(ofs, ox)); 64782b749b2SAmir Goldstein ofs->noxattr = true; 64882b749b2SAmir Goldstein return xerr; 64982b749b2SAmir Goldstein } 65082b749b2SAmir Goldstein 65182b749b2SAmir Goldstein return err; 65282b749b2SAmir Goldstein } 653f3a15685SAmir Goldstein 654f3a15685SAmir Goldstein int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry) 655f3a15685SAmir Goldstein { 656a0c236b1SAmir Goldstein struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 657f3a15685SAmir Goldstein int err; 658f3a15685SAmir Goldstein 65913c72075SMiklos Szeredi if (ovl_test_flag(OVL_IMPURE, d_inode(dentry))) 660f3a15685SAmir Goldstein return 0; 661f3a15685SAmir Goldstein 662f3a15685SAmir Goldstein /* 663f3a15685SAmir Goldstein * Do not fail when upper doesn't support xattrs. 664f3a15685SAmir Goldstein * Upper inodes won't have origin nor redirect xattr anyway. 665f3a15685SAmir Goldstein */ 666a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, upperdentry, OVL_XATTR_IMPURE, "y", 1, 0); 667f3a15685SAmir Goldstein if (!err) 66813c72075SMiklos Szeredi ovl_set_flag(OVL_IMPURE, d_inode(dentry)); 669f3a15685SAmir Goldstein 670f3a15685SAmir Goldstein return err; 671f3a15685SAmir Goldstein } 67213c72075SMiklos Szeredi 673096a218aSAmir Goldstein 674096a218aSAmir Goldstein #define OVL_PROTATTR_MAX 32 /* Reserved for future flags */ 675096a218aSAmir Goldstein 676096a218aSAmir Goldstein void ovl_check_protattr(struct inode *inode, struct dentry *upper) 677096a218aSAmir Goldstein { 678096a218aSAmir Goldstein struct ovl_fs *ofs = OVL_FS(inode->i_sb); 679096a218aSAmir Goldstein u32 iflags = inode->i_flags & OVL_PROT_I_FLAGS_MASK; 680096a218aSAmir Goldstein char buf[OVL_PROTATTR_MAX+1]; 681096a218aSAmir Goldstein int res, n; 682096a218aSAmir Goldstein 683dad7017aSChristian Brauner res = ovl_getxattr_upper(ofs, upper, OVL_XATTR_PROTATTR, buf, 684096a218aSAmir Goldstein OVL_PROTATTR_MAX); 685096a218aSAmir Goldstein if (res < 0) 686096a218aSAmir Goldstein return; 687096a218aSAmir Goldstein 688096a218aSAmir Goldstein /* 689096a218aSAmir Goldstein * Initialize inode flags from overlay.protattr xattr and upper inode 690096a218aSAmir Goldstein * flags. If upper inode has those fileattr flags set (i.e. from old 691096a218aSAmir Goldstein * kernel), we do not clear them on ovl_get_inode(), but we will clear 692096a218aSAmir Goldstein * them on next fileattr_set(). 693096a218aSAmir Goldstein */ 694096a218aSAmir Goldstein for (n = 0; n < res; n++) { 695096a218aSAmir Goldstein if (buf[n] == 'a') 696096a218aSAmir Goldstein iflags |= S_APPEND; 697096a218aSAmir Goldstein else if (buf[n] == 'i') 698096a218aSAmir Goldstein iflags |= S_IMMUTABLE; 699096a218aSAmir Goldstein else 700096a218aSAmir Goldstein break; 701096a218aSAmir Goldstein } 702096a218aSAmir Goldstein 703096a218aSAmir Goldstein if (!res || n < res) { 704096a218aSAmir Goldstein pr_warn_ratelimited("incompatible overlay.protattr format (%pd2, len=%d)\n", 705096a218aSAmir Goldstein upper, res); 706096a218aSAmir Goldstein } else { 707096a218aSAmir Goldstein inode_set_flags(inode, iflags, OVL_PROT_I_FLAGS_MASK); 708096a218aSAmir Goldstein } 709096a218aSAmir Goldstein } 710096a218aSAmir Goldstein 711096a218aSAmir Goldstein int ovl_set_protattr(struct inode *inode, struct dentry *upper, 712096a218aSAmir Goldstein struct fileattr *fa) 713096a218aSAmir Goldstein { 714096a218aSAmir Goldstein struct ovl_fs *ofs = OVL_FS(inode->i_sb); 715096a218aSAmir Goldstein char buf[OVL_PROTATTR_MAX]; 716096a218aSAmir Goldstein int len = 0, err = 0; 717096a218aSAmir Goldstein u32 iflags = 0; 718096a218aSAmir Goldstein 719096a218aSAmir Goldstein BUILD_BUG_ON(HWEIGHT32(OVL_PROT_FS_FLAGS_MASK) > OVL_PROTATTR_MAX); 720096a218aSAmir Goldstein 721096a218aSAmir Goldstein if (fa->flags & FS_APPEND_FL) { 722096a218aSAmir Goldstein buf[len++] = 'a'; 723096a218aSAmir Goldstein iflags |= S_APPEND; 724096a218aSAmir Goldstein } 725096a218aSAmir Goldstein if (fa->flags & FS_IMMUTABLE_FL) { 726096a218aSAmir Goldstein buf[len++] = 'i'; 727096a218aSAmir Goldstein iflags |= S_IMMUTABLE; 728096a218aSAmir Goldstein } 729096a218aSAmir Goldstein 730096a218aSAmir Goldstein /* 731096a218aSAmir Goldstein * Do not allow to set protection flags when upper doesn't support 732096a218aSAmir Goldstein * xattrs, because we do not set those fileattr flags on upper inode. 733096a218aSAmir Goldstein * Remove xattr if it exist and all protection flags are cleared. 734096a218aSAmir Goldstein */ 735096a218aSAmir Goldstein if (len) { 736096a218aSAmir Goldstein err = ovl_check_setxattr(ofs, upper, OVL_XATTR_PROTATTR, 737096a218aSAmir Goldstein buf, len, -EPERM); 738096a218aSAmir Goldstein } else if (inode->i_flags & OVL_PROT_I_FLAGS_MASK) { 739c914c0e2SAmir Goldstein err = ovl_removexattr(ofs, upper, OVL_XATTR_PROTATTR); 740096a218aSAmir Goldstein if (err == -EOPNOTSUPP || err == -ENODATA) 741096a218aSAmir Goldstein err = 0; 742096a218aSAmir Goldstein } 743096a218aSAmir Goldstein if (err) 744096a218aSAmir Goldstein return err; 745096a218aSAmir Goldstein 746096a218aSAmir Goldstein inode_set_flags(inode, iflags, OVL_PROT_I_FLAGS_MASK); 747096a218aSAmir Goldstein 748096a218aSAmir Goldstein /* Mask out the fileattr flags that should not be set in upper inode */ 749096a218aSAmir Goldstein fa->flags &= ~OVL_PROT_FS_FLAGS_MASK; 750096a218aSAmir Goldstein fa->fsx_xflags &= ~OVL_PROT_FSX_FLAGS_MASK; 751096a218aSAmir Goldstein 752096a218aSAmir Goldstein return 0; 753096a218aSAmir Goldstein } 754096a218aSAmir Goldstein 755ad0af710SAmir Goldstein /** 756ad0af710SAmir Goldstein * Caller must hold a reference to inode to prevent it from being freed while 757ad0af710SAmir Goldstein * it is marked inuse. 758ad0af710SAmir Goldstein */ 759ad0af710SAmir Goldstein bool ovl_inuse_trylock(struct dentry *dentry) 760ad0af710SAmir Goldstein { 761ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 762ad0af710SAmir Goldstein bool locked = false; 763ad0af710SAmir Goldstein 764ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 765ad0af710SAmir Goldstein if (!(inode->i_state & I_OVL_INUSE)) { 766ad0af710SAmir Goldstein inode->i_state |= I_OVL_INUSE; 767ad0af710SAmir Goldstein locked = true; 768ad0af710SAmir Goldstein } 769ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 770ad0af710SAmir Goldstein 771ad0af710SAmir Goldstein return locked; 772ad0af710SAmir Goldstein } 773ad0af710SAmir Goldstein 774ad0af710SAmir Goldstein void ovl_inuse_unlock(struct dentry *dentry) 775ad0af710SAmir Goldstein { 776ad0af710SAmir Goldstein if (dentry) { 777ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 778ad0af710SAmir Goldstein 779ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 780ad0af710SAmir Goldstein WARN_ON(!(inode->i_state & I_OVL_INUSE)); 781ad0af710SAmir Goldstein inode->i_state &= ~I_OVL_INUSE; 782ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 783ad0af710SAmir Goldstein } 784ad0af710SAmir Goldstein } 7855f8415d6SAmir Goldstein 786146d62e5SAmir Goldstein bool ovl_is_inuse(struct dentry *dentry) 787146d62e5SAmir Goldstein { 788146d62e5SAmir Goldstein struct inode *inode = d_inode(dentry); 789146d62e5SAmir Goldstein bool inuse; 790146d62e5SAmir Goldstein 791146d62e5SAmir Goldstein spin_lock(&inode->i_lock); 792146d62e5SAmir Goldstein inuse = (inode->i_state & I_OVL_INUSE); 793146d62e5SAmir Goldstein spin_unlock(&inode->i_lock); 794146d62e5SAmir Goldstein 795146d62e5SAmir Goldstein return inuse; 796146d62e5SAmir Goldstein } 797146d62e5SAmir Goldstein 79824b33ee1SAmir Goldstein /* 79924b33ee1SAmir Goldstein * Does this overlay dentry need to be indexed on copy up? 80024b33ee1SAmir Goldstein */ 80124b33ee1SAmir Goldstein bool ovl_need_index(struct dentry *dentry) 80224b33ee1SAmir Goldstein { 80324b33ee1SAmir Goldstein struct dentry *lower = ovl_dentry_lower(dentry); 80424b33ee1SAmir Goldstein 80524b33ee1SAmir Goldstein if (!lower || !ovl_indexdir(dentry->d_sb)) 80624b33ee1SAmir Goldstein return false; 80724b33ee1SAmir Goldstein 808fbd2d207SAmir Goldstein /* Index all files for NFS export and consistency verification */ 809016b720fSAmir Goldstein if (ovl_index_all(dentry->d_sb)) 810fbd2d207SAmir Goldstein return true; 811fbd2d207SAmir Goldstein 81224b33ee1SAmir Goldstein /* Index only lower hardlinks on copy up */ 81324b33ee1SAmir Goldstein if (!d_is_dir(lower) && d_inode(lower)->i_nlink > 1) 81424b33ee1SAmir Goldstein return true; 81524b33ee1SAmir Goldstein 81624b33ee1SAmir Goldstein return false; 81724b33ee1SAmir Goldstein } 81824b33ee1SAmir Goldstein 8199f4ec904SAmir Goldstein /* Caller must hold OVL_I(inode)->lock */ 820caf70cb2SAmir Goldstein static void ovl_cleanup_index(struct dentry *dentry) 821caf70cb2SAmir Goldstein { 8221cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 823e7dd0e71SAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 824e7dd0e71SAmir Goldstein struct inode *dir = indexdir->d_inode; 825caf70cb2SAmir Goldstein struct dentry *lowerdentry = ovl_dentry_lower(dentry); 826caf70cb2SAmir Goldstein struct dentry *upperdentry = ovl_dentry_upper(dentry); 827caf70cb2SAmir Goldstein struct dentry *index = NULL; 828caf70cb2SAmir Goldstein struct inode *inode; 82963e13252SAmir Goldstein struct qstr name = { }; 830caf70cb2SAmir Goldstein int err; 831caf70cb2SAmir Goldstein 8321cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, lowerdentry, &name); 833caf70cb2SAmir Goldstein if (err) 834caf70cb2SAmir Goldstein goto fail; 835caf70cb2SAmir Goldstein 836caf70cb2SAmir Goldstein inode = d_inode(upperdentry); 83789a17556SAmir Goldstein if (!S_ISDIR(inode->i_mode) && inode->i_nlink != 1) { 8381bd0a3aeSlijiazi pr_warn_ratelimited("cleanup linked index (%pd2, ino=%lu, nlink=%u)\n", 839caf70cb2SAmir Goldstein upperdentry, inode->i_ino, inode->i_nlink); 840caf70cb2SAmir Goldstein /* 841caf70cb2SAmir Goldstein * We either have a bug with persistent union nlink or a lower 842caf70cb2SAmir Goldstein * hardlink was added while overlay is mounted. Adding a lower 843caf70cb2SAmir Goldstein * hardlink and then unlinking all overlay hardlinks would drop 844caf70cb2SAmir Goldstein * overlay nlink to zero before all upper inodes are unlinked. 845caf70cb2SAmir Goldstein * As a safety measure, when that situation is detected, set 846caf70cb2SAmir Goldstein * the overlay nlink to the index inode nlink minus one for the 847caf70cb2SAmir Goldstein * index entry itself. 848caf70cb2SAmir Goldstein */ 849caf70cb2SAmir Goldstein set_nlink(d_inode(dentry), inode->i_nlink - 1); 850caf70cb2SAmir Goldstein ovl_set_nlink_upper(dentry); 851caf70cb2SAmir Goldstein goto out; 852caf70cb2SAmir Goldstein } 853caf70cb2SAmir Goldstein 854caf70cb2SAmir Goldstein inode_lock_nested(dir, I_MUTEX_PARENT); 85522f289ceSChristian Brauner index = ovl_lookup_upper(ofs, name.name, indexdir, name.len); 856caf70cb2SAmir Goldstein err = PTR_ERR(index); 857e7dd0e71SAmir Goldstein if (IS_ERR(index)) { 8589f4ec904SAmir Goldstein index = NULL; 859e7dd0e71SAmir Goldstein } else if (ovl_index_all(dentry->d_sb)) { 860e7dd0e71SAmir Goldstein /* Whiteout orphan index to block future open by handle */ 861c21c839bSChengguang Xu err = ovl_cleanup_and_whiteout(OVL_FS(dentry->d_sb), 862c21c839bSChengguang Xu dir, index); 863e7dd0e71SAmir Goldstein } else { 864e7dd0e71SAmir Goldstein /* Cleanup orphan index entries */ 865576bb263SChristian Brauner err = ovl_cleanup(ofs, dir, index); 866e7dd0e71SAmir Goldstein } 8679f4ec904SAmir Goldstein 868caf70cb2SAmir Goldstein inode_unlock(dir); 869caf70cb2SAmir Goldstein if (err) 870caf70cb2SAmir Goldstein goto fail; 871caf70cb2SAmir Goldstein 872caf70cb2SAmir Goldstein out: 87363e13252SAmir Goldstein kfree(name.name); 874caf70cb2SAmir Goldstein dput(index); 875caf70cb2SAmir Goldstein return; 876caf70cb2SAmir Goldstein 877caf70cb2SAmir Goldstein fail: 8781bd0a3aeSlijiazi pr_err("cleanup index of '%pd2' failed (%i)\n", dentry, err); 879caf70cb2SAmir Goldstein goto out; 880caf70cb2SAmir Goldstein } 881caf70cb2SAmir Goldstein 8825f8415d6SAmir Goldstein /* 8835f8415d6SAmir Goldstein * Operations that change overlay inode and upper inode nlink need to be 8845f8415d6SAmir Goldstein * synchronized with copy up for persistent nlink accounting. 8855f8415d6SAmir Goldstein */ 8860e32992fSAmir Goldstein int ovl_nlink_start(struct dentry *dentry) 8875f8415d6SAmir Goldstein { 8881e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 8895f8415d6SAmir Goldstein const struct cred *old_cred; 8905f8415d6SAmir Goldstein int err; 8915f8415d6SAmir Goldstein 8921e92e307SAmir Goldstein if (WARN_ON(!inode)) 8930e32992fSAmir Goldstein return -ENOENT; 8945f8415d6SAmir Goldstein 8955f8415d6SAmir Goldstein /* 8965f8415d6SAmir Goldstein * With inodes index is enabled, we store the union overlay nlink 89724b33ee1SAmir Goldstein * in an xattr on the index inode. When whiting out an indexed lower, 8985f8415d6SAmir Goldstein * we need to decrement the overlay persistent nlink, but before the 8995f8415d6SAmir Goldstein * first copy up, we have no upper index inode to store the xattr. 9005f8415d6SAmir Goldstein * 90124b33ee1SAmir Goldstein * As a workaround, before whiteout/rename over an indexed lower, 9025f8415d6SAmir Goldstein * copy up to create the upper index. Creating the upper index will 9035f8415d6SAmir Goldstein * initialize the overlay nlink, so it could be dropped if unlink 9045f8415d6SAmir Goldstein * or rename succeeds. 9055f8415d6SAmir Goldstein * 9065f8415d6SAmir Goldstein * TODO: implement metadata only index copy up when called with 9075f8415d6SAmir Goldstein * ovl_copy_up_flags(dentry, O_PATH). 9085f8415d6SAmir Goldstein */ 90924b33ee1SAmir Goldstein if (ovl_need_index(dentry) && !ovl_dentry_has_upper_alias(dentry)) { 9105f8415d6SAmir Goldstein err = ovl_copy_up(dentry); 9115f8415d6SAmir Goldstein if (err) 9125f8415d6SAmir Goldstein return err; 9135f8415d6SAmir Goldstein } 9145f8415d6SAmir Goldstein 915531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 9165f8415d6SAmir Goldstein if (err) 9175f8415d6SAmir Goldstein return err; 9185f8415d6SAmir Goldstein 9191e92e307SAmir Goldstein if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, inode)) 9205f8415d6SAmir Goldstein goto out; 9215f8415d6SAmir Goldstein 9225f8415d6SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 9235f8415d6SAmir Goldstein /* 9245f8415d6SAmir Goldstein * The overlay inode nlink should be incremented/decremented IFF the 9255f8415d6SAmir Goldstein * upper operation succeeds, along with nlink change of upper inode. 9265f8415d6SAmir Goldstein * Therefore, before link/unlink/rename, we store the union nlink 9275f8415d6SAmir Goldstein * value relative to the upper inode nlink in an upper inode xattr. 9285f8415d6SAmir Goldstein */ 9295f8415d6SAmir Goldstein err = ovl_set_nlink_upper(dentry); 9305f8415d6SAmir Goldstein revert_creds(old_cred); 9315f8415d6SAmir Goldstein 9325f8415d6SAmir Goldstein out: 9335f8415d6SAmir Goldstein if (err) 9341e92e307SAmir Goldstein ovl_inode_unlock(inode); 9355f8415d6SAmir Goldstein 9365f8415d6SAmir Goldstein return err; 9375f8415d6SAmir Goldstein } 9385f8415d6SAmir Goldstein 9390e32992fSAmir Goldstein void ovl_nlink_end(struct dentry *dentry) 9405f8415d6SAmir Goldstein { 9411e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 9421e92e307SAmir Goldstein 9431e92e307SAmir Goldstein if (ovl_test_flag(OVL_INDEX, inode) && inode->i_nlink == 0) { 944caf70cb2SAmir Goldstein const struct cred *old_cred; 945caf70cb2SAmir Goldstein 946caf70cb2SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 947caf70cb2SAmir Goldstein ovl_cleanup_index(dentry); 948caf70cb2SAmir Goldstein revert_creds(old_cred); 949caf70cb2SAmir Goldstein } 950caf70cb2SAmir Goldstein 9511e92e307SAmir Goldstein ovl_inode_unlock(inode); 9525f8415d6SAmir Goldstein } 9535820dc08SAmir Goldstein 9545820dc08SAmir Goldstein int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir) 9555820dc08SAmir Goldstein { 9565820dc08SAmir Goldstein /* Workdir should not be the same as upperdir */ 9575820dc08SAmir Goldstein if (workdir == upperdir) 9585820dc08SAmir Goldstein goto err; 9595820dc08SAmir Goldstein 9605820dc08SAmir Goldstein /* Workdir should not be subdir of upperdir and vice versa */ 9615820dc08SAmir Goldstein if (lock_rename(workdir, upperdir) != NULL) 9625820dc08SAmir Goldstein goto err_unlock; 9635820dc08SAmir Goldstein 9645820dc08SAmir Goldstein return 0; 9655820dc08SAmir Goldstein 9665820dc08SAmir Goldstein err_unlock: 9675820dc08SAmir Goldstein unlock_rename(workdir, upperdir); 9685820dc08SAmir Goldstein err: 9691bd0a3aeSlijiazi pr_err("failed to lock workdir+upperdir\n"); 9705820dc08SAmir Goldstein return -EIO; 9715820dc08SAmir Goldstein } 9729d3dfea3SVivek Goyal 9739d3dfea3SVivek Goyal /* err < 0, 0 if no metacopy xattr, 1 if metacopy xattr found */ 9742d343087SAl Viro int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path) 9759d3dfea3SVivek Goyal { 9769d3dfea3SVivek Goyal int res; 9779d3dfea3SVivek Goyal 9789d3dfea3SVivek Goyal /* Only regular files can have metacopy xattr */ 979dad7017aSChristian Brauner if (!S_ISREG(d_inode(path->dentry)->i_mode)) 9809d3dfea3SVivek Goyal return 0; 9819d3dfea3SVivek Goyal 982dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_METACOPY, NULL, 0); 9839d3dfea3SVivek Goyal if (res < 0) { 9849d3dfea3SVivek Goyal if (res == -ENODATA || res == -EOPNOTSUPP) 9859d3dfea3SVivek Goyal return 0; 98687b2c60cSMiklos Szeredi /* 98787b2c60cSMiklos Szeredi * getxattr on user.* may fail with EACCES in case there's no 98887b2c60cSMiklos Szeredi * read permission on the inode. Not much we can do, other than 98987b2c60cSMiklos Szeredi * tell the caller that this is not a metacopy inode. 99087b2c60cSMiklos Szeredi */ 99187b2c60cSMiklos Szeredi if (ofs->config.userxattr && res == -EACCES) 99287b2c60cSMiklos Szeredi return 0; 9939d3dfea3SVivek Goyal goto out; 9949d3dfea3SVivek Goyal } 9959d3dfea3SVivek Goyal 9969d3dfea3SVivek Goyal return 1; 9979d3dfea3SVivek Goyal out: 9981bd0a3aeSlijiazi pr_warn_ratelimited("failed to get metacopy (%i)\n", res); 9999d3dfea3SVivek Goyal return res; 10009d3dfea3SVivek Goyal } 100167d756c2SVivek Goyal 100267d756c2SVivek Goyal bool ovl_is_metacopy_dentry(struct dentry *dentry) 100367d756c2SVivek Goyal { 100467d756c2SVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 100567d756c2SVivek Goyal 100667d756c2SVivek Goyal if (!d_is_reg(dentry)) 100767d756c2SVivek Goyal return false; 100867d756c2SVivek Goyal 100967d756c2SVivek Goyal if (ovl_dentry_upper(dentry)) { 101067d756c2SVivek Goyal if (!ovl_has_upperdata(d_inode(dentry))) 101167d756c2SVivek Goyal return true; 101267d756c2SVivek Goyal return false; 101367d756c2SVivek Goyal } 101467d756c2SVivek Goyal 101567d756c2SVivek Goyal return (oe->numlower > 1); 101667d756c2SVivek Goyal } 10170a2d0d3fSVivek Goyal 10182d343087SAl Viro char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding) 10190a2d0d3fSVivek Goyal { 10200a2d0d3fSVivek Goyal int res; 10210a2d0d3fSVivek Goyal char *s, *next, *buf = NULL; 10220a2d0d3fSVivek Goyal 1023dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_REDIRECT, NULL, 0); 102492f0d6c9SMiklos Szeredi if (res == -ENODATA || res == -EOPNOTSUPP) 10250a2d0d3fSVivek Goyal return NULL; 10260a2d0d3fSVivek Goyal if (res < 0) 102792f0d6c9SMiklos Szeredi goto fail; 102892f0d6c9SMiklos Szeredi if (res == 0) 102992f0d6c9SMiklos Szeredi goto invalid; 103092f0d6c9SMiklos Szeredi 103192f0d6c9SMiklos Szeredi buf = kzalloc(res + padding + 1, GFP_KERNEL); 103292f0d6c9SMiklos Szeredi if (!buf) 103392f0d6c9SMiklos Szeredi return ERR_PTR(-ENOMEM); 103492f0d6c9SMiklos Szeredi 1035dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_REDIRECT, buf, res); 103692f0d6c9SMiklos Szeredi if (res < 0) 103792f0d6c9SMiklos Szeredi goto fail; 10380a2d0d3fSVivek Goyal if (res == 0) 10390a2d0d3fSVivek Goyal goto invalid; 10400a2d0d3fSVivek Goyal 10410a2d0d3fSVivek Goyal if (buf[0] == '/') { 10420a2d0d3fSVivek Goyal for (s = buf; *s++ == '/'; s = next) { 10430a2d0d3fSVivek Goyal next = strchrnul(s, '/'); 10440a2d0d3fSVivek Goyal if (s == next) 10450a2d0d3fSVivek Goyal goto invalid; 10460a2d0d3fSVivek Goyal } 10470a2d0d3fSVivek Goyal } else { 10480a2d0d3fSVivek Goyal if (strchr(buf, '/') != NULL) 10490a2d0d3fSVivek Goyal goto invalid; 10500a2d0d3fSVivek Goyal } 10510a2d0d3fSVivek Goyal 10520a2d0d3fSVivek Goyal return buf; 10530a2d0d3fSVivek Goyal invalid: 10541bd0a3aeSlijiazi pr_warn_ratelimited("invalid redirect (%s)\n", buf); 10550a2d0d3fSVivek Goyal res = -EINVAL; 105692f0d6c9SMiklos Szeredi goto err_free; 105792f0d6c9SMiklos Szeredi fail: 105892f0d6c9SMiklos Szeredi pr_warn_ratelimited("failed to get redirect (%i)\n", res); 105992f0d6c9SMiklos Szeredi err_free: 1060993a0b2aSVivek Goyal kfree(buf); 1061993a0b2aSVivek Goyal return ERR_PTR(res); 10620a2d0d3fSVivek Goyal } 1063335d3fc5SSargun Dhillon 1064335d3fc5SSargun Dhillon /* 1065335d3fc5SSargun Dhillon * ovl_sync_status() - Check fs sync status for volatile mounts 1066335d3fc5SSargun Dhillon * 1067335d3fc5SSargun Dhillon * Returns 1 if this is not a volatile mount and a real sync is required. 1068335d3fc5SSargun Dhillon * 1069335d3fc5SSargun Dhillon * Returns 0 if syncing can be skipped because mount is volatile, and no errors 1070335d3fc5SSargun Dhillon * have occurred on the upperdir since the mount. 1071335d3fc5SSargun Dhillon * 1072335d3fc5SSargun Dhillon * Returns -errno if it is a volatile mount, and the error that occurred since 1073335d3fc5SSargun Dhillon * the last mount. If the error code changes, it'll return the latest error 1074335d3fc5SSargun Dhillon * code. 1075335d3fc5SSargun Dhillon */ 1076335d3fc5SSargun Dhillon 1077335d3fc5SSargun Dhillon int ovl_sync_status(struct ovl_fs *ofs) 1078335d3fc5SSargun Dhillon { 1079335d3fc5SSargun Dhillon struct vfsmount *mnt; 1080335d3fc5SSargun Dhillon 1081335d3fc5SSargun Dhillon if (ovl_should_sync(ofs)) 1082335d3fc5SSargun Dhillon return 1; 1083335d3fc5SSargun Dhillon 1084335d3fc5SSargun Dhillon mnt = ovl_upper_mnt(ofs); 1085335d3fc5SSargun Dhillon if (!mnt) 1086335d3fc5SSargun Dhillon return 0; 1087335d3fc5SSargun Dhillon 1088335d3fc5SSargun Dhillon return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq); 1089335d3fc5SSargun Dhillon } 10902878dffcSChristian Brauner 10912878dffcSChristian Brauner /* 10922878dffcSChristian Brauner * ovl_copyattr() - copy inode attributes from layer to ovl inode 10932878dffcSChristian Brauner * 10942878dffcSChristian Brauner * When overlay copies inode information from an upper or lower layer to the 10952878dffcSChristian Brauner * relevant overlay inode it will apply the idmapping of the upper or lower 10962878dffcSChristian Brauner * layer when doing so ensuring that the ovl inode ownership will correctly 10972878dffcSChristian Brauner * reflect the ownership of the idmapped upper or lower layer. For example, an 10982878dffcSChristian Brauner * idmapped upper or lower layer mapping id 1001 to id 1000 will take care to 10992878dffcSChristian Brauner * map any lower or upper inode owned by id 1001 to id 1000. These mapping 11002878dffcSChristian Brauner * helpers are nops when the relevant layer isn't idmapped. 11012878dffcSChristian Brauner */ 11022878dffcSChristian Brauner void ovl_copyattr(struct inode *inode) 11032878dffcSChristian Brauner { 11042878dffcSChristian Brauner struct path realpath; 11052878dffcSChristian Brauner struct inode *realinode; 11062878dffcSChristian Brauner struct user_namespace *real_mnt_userns; 1107*73db6a06SChristian Brauner vfsuid_t vfsuid; 1108*73db6a06SChristian Brauner vfsgid_t vfsgid; 11092878dffcSChristian Brauner 11102878dffcSChristian Brauner ovl_i_path_real(inode, &realpath); 11112878dffcSChristian Brauner realinode = d_inode(realpath.dentry); 11122878dffcSChristian Brauner real_mnt_userns = mnt_user_ns(realpath.mnt); 11132878dffcSChristian Brauner 1114*73db6a06SChristian Brauner vfsuid = i_uid_into_vfsuid(real_mnt_userns, realinode); 1115*73db6a06SChristian Brauner vfsgid = i_gid_into_vfsgid(real_mnt_userns, realinode); 1116*73db6a06SChristian Brauner 1117*73db6a06SChristian Brauner inode->i_uid = vfsuid_into_kuid(vfsuid); 1118*73db6a06SChristian Brauner inode->i_gid = vfsgid_into_kgid(vfsgid); 11192878dffcSChristian Brauner inode->i_mode = realinode->i_mode; 11202878dffcSChristian Brauner inode->i_atime = realinode->i_atime; 11212878dffcSChristian Brauner inode->i_mtime = realinode->i_mtime; 11222878dffcSChristian Brauner inode->i_ctime = realinode->i_ctime; 11232878dffcSChristian Brauner i_size_write(inode, i_size_read(realinode)); 11242878dffcSChristian Brauner } 1125