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 { 88*5522c9c7SAmir Goldstein 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) 92*5522c9c7SAmir Goldstein oe->__numlower = numlower; 93bbb1e54dSMiklos Szeredi 94bbb1e54dSMiklos Szeredi return oe; 95bbb1e54dSMiklos Szeredi } 96bbb1e54dSMiklos Szeredi 97b07d5cc9SAmir Goldstein #define OVL_D_REVALIDATE (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE) 98b07d5cc9SAmir Goldstein 99bbb1e54dSMiklos Szeredi bool ovl_dentry_remote(struct dentry *dentry) 100bbb1e54dSMiklos Szeredi { 101b07d5cc9SAmir Goldstein return dentry->d_flags & OVL_D_REVALIDATE; 102bbb1e54dSMiklos Szeredi } 103bbb1e54dSMiklos Szeredi 104b07d5cc9SAmir Goldstein void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry) 105b07d5cc9SAmir Goldstein { 106b07d5cc9SAmir Goldstein if (!ovl_dentry_remote(realdentry)) 107b07d5cc9SAmir Goldstein return; 108b07d5cc9SAmir Goldstein 109b07d5cc9SAmir Goldstein spin_lock(&dentry->d_lock); 110b07d5cc9SAmir Goldstein dentry->d_flags |= realdentry->d_flags & OVL_D_REVALIDATE; 111b07d5cc9SAmir Goldstein spin_unlock(&dentry->d_lock); 112b07d5cc9SAmir Goldstein } 113b07d5cc9SAmir Goldstein 114b07d5cc9SAmir Goldstein void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry) 115b07d5cc9SAmir Goldstein { 116b07d5cc9SAmir Goldstein return ovl_dentry_init_flags(dentry, upperdentry, OVL_D_REVALIDATE); 117b07d5cc9SAmir Goldstein } 118b07d5cc9SAmir Goldstein 119b07d5cc9SAmir Goldstein void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 120f4288844SMiklos Szeredi unsigned int mask) 121f4288844SMiklos Szeredi { 122f4288844SMiklos Szeredi struct ovl_entry *oe = OVL_E(dentry); 123*5522c9c7SAmir Goldstein struct ovl_path *lowerstack = ovl_lowerstack(oe); 124f4288844SMiklos Szeredi unsigned int i, flags = 0; 125f4288844SMiklos Szeredi 126bccece1eSMiklos Szeredi if (upperdentry) 127bccece1eSMiklos Szeredi flags |= upperdentry->d_flags; 128*5522c9c7SAmir Goldstein for (i = 0; i < ovl_numlower(oe); i++) 129*5522c9c7SAmir Goldstein flags |= lowerstack[i].dentry->d_flags; 130f4288844SMiklos Szeredi 131f4288844SMiklos Szeredi spin_lock(&dentry->d_lock); 132f4288844SMiklos Szeredi dentry->d_flags &= ~mask; 133f4288844SMiklos Szeredi dentry->d_flags |= flags & mask; 134f4288844SMiklos Szeredi spin_unlock(&dentry->d_lock); 135f4288844SMiklos Szeredi } 136f4288844SMiklos Szeredi 137bbb1e54dSMiklos Szeredi bool ovl_dentry_weird(struct dentry *dentry) 138bbb1e54dSMiklos Szeredi { 139bbb1e54dSMiklos Szeredi return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT | 140bbb1e54dSMiklos Szeredi DCACHE_MANAGE_TRANSIT | 141bbb1e54dSMiklos Szeredi DCACHE_OP_HASH | 142bbb1e54dSMiklos Szeredi DCACHE_OP_COMPARE); 143bbb1e54dSMiklos Szeredi } 144bbb1e54dSMiklos Szeredi 145bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_type(struct dentry *dentry) 146bbb1e54dSMiklos Szeredi { 147a6ff2bc0SAmir Goldstein struct ovl_entry *oe = OVL_E(dentry); 148bbb1e54dSMiklos Szeredi enum ovl_path_type type = 0; 149bbb1e54dSMiklos Szeredi 15009d8b586SMiklos Szeredi if (ovl_dentry_upper(dentry)) { 151bbb1e54dSMiklos Szeredi type = __OVL_PATH_UPPER; 152bbb1e54dSMiklos Szeredi 153bbb1e54dSMiklos Szeredi /* 15459548503SAmir Goldstein * Non-dir dentry can hold lower dentry of its copy up origin. 155bbb1e54dSMiklos Szeredi */ 156*5522c9c7SAmir Goldstein if (ovl_numlower(oe)) { 15760124877SVivek Goyal if (ovl_test_flag(OVL_CONST_INO, d_inode(dentry))) 15859548503SAmir Goldstein type |= __OVL_PATH_ORIGIN; 1590b17c28aSVivek Goyal if (d_is_dir(dentry) || 1600b17c28aSVivek Goyal !ovl_has_upperdata(d_inode(dentry))) 161bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 16259548503SAmir Goldstein } 163bbb1e54dSMiklos Szeredi } else { 164*5522c9c7SAmir Goldstein if (ovl_numlower(oe) > 1) 165bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 166bbb1e54dSMiklos Szeredi } 167bbb1e54dSMiklos Szeredi return type; 168bbb1e54dSMiklos Szeredi } 169bbb1e54dSMiklos Szeredi 170bbb1e54dSMiklos Szeredi void ovl_path_upper(struct dentry *dentry, struct path *path) 171bbb1e54dSMiklos Szeredi { 172bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 173bbb1e54dSMiklos Szeredi 17408f4c7c8SMiklos Szeredi path->mnt = ovl_upper_mnt(ofs); 17509d8b586SMiklos Szeredi path->dentry = ovl_dentry_upper(dentry); 176bbb1e54dSMiklos Szeredi } 177bbb1e54dSMiklos Szeredi 178bbb1e54dSMiklos Szeredi void ovl_path_lower(struct dentry *dentry, struct path *path) 179bbb1e54dSMiklos Szeredi { 180a6ff2bc0SAmir Goldstein struct ovl_entry *oe = OVL_E(dentry); 181*5522c9c7SAmir Goldstein struct ovl_path *lowerpath = ovl_lowerstack(oe); 182bbb1e54dSMiklos Szeredi 183*5522c9c7SAmir Goldstein if (ovl_numlower(oe)) { 184*5522c9c7SAmir Goldstein path->mnt = lowerpath->layer->mnt; 185*5522c9c7SAmir Goldstein path->dentry = lowerpath->dentry; 186b9343632SChandan Rajendra } else { 187b9343632SChandan Rajendra *path = (struct path) { }; 188b9343632SChandan Rajendra } 189bbb1e54dSMiklos Szeredi } 190bbb1e54dSMiklos Szeredi 1914f93b426SVivek Goyal void ovl_path_lowerdata(struct dentry *dentry, struct path *path) 1924f93b426SVivek Goyal { 193a6ff2bc0SAmir Goldstein struct ovl_entry *oe = OVL_E(dentry); 194*5522c9c7SAmir Goldstein struct ovl_path *lowerstack = ovl_lowerstack(oe); 1954f93b426SVivek Goyal 196*5522c9c7SAmir Goldstein if (ovl_numlower(oe)) { 197*5522c9c7SAmir Goldstein path->mnt = lowerstack[ovl_numlower(oe) - 1].layer->mnt; 198*5522c9c7SAmir Goldstein path->dentry = lowerstack[ovl_numlower(oe) - 1].dentry; 1994f93b426SVivek Goyal } else { 2004f93b426SVivek Goyal *path = (struct path) { }; 2014f93b426SVivek Goyal } 2024f93b426SVivek Goyal } 2034f93b426SVivek Goyal 204bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) 205bbb1e54dSMiklos Szeredi { 206bbb1e54dSMiklos Szeredi enum ovl_path_type type = ovl_path_type(dentry); 207bbb1e54dSMiklos Szeredi 208bbb1e54dSMiklos Szeredi if (!OVL_TYPE_UPPER(type)) 209bbb1e54dSMiklos Szeredi ovl_path_lower(dentry, path); 210bbb1e54dSMiklos Szeredi else 211bbb1e54dSMiklos Szeredi ovl_path_upper(dentry, path); 212bbb1e54dSMiklos Szeredi 213bbb1e54dSMiklos Szeredi return type; 214bbb1e54dSMiklos Szeredi } 215bbb1e54dSMiklos Szeredi 2161248ea4bSAmir Goldstein enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path) 2171248ea4bSAmir Goldstein { 2181248ea4bSAmir Goldstein enum ovl_path_type type = ovl_path_type(dentry); 2191248ea4bSAmir Goldstein 2201248ea4bSAmir Goldstein WARN_ON_ONCE(d_is_dir(dentry)); 2211248ea4bSAmir Goldstein 2221248ea4bSAmir Goldstein if (!OVL_TYPE_UPPER(type) || OVL_TYPE_MERGE(type)) 2231248ea4bSAmir Goldstein ovl_path_lowerdata(dentry, path); 2241248ea4bSAmir Goldstein else 2251248ea4bSAmir Goldstein ovl_path_upper(dentry, path); 2261248ea4bSAmir Goldstein 2271248ea4bSAmir Goldstein return type; 2281248ea4bSAmir Goldstein } 2291248ea4bSAmir Goldstein 230bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_upper(struct dentry *dentry) 231bbb1e54dSMiklos Szeredi { 23209d8b586SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(d_inode(dentry))); 233bbb1e54dSMiklos Szeredi } 234bbb1e54dSMiklos Szeredi 235bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_lower(struct dentry *dentry) 236bbb1e54dSMiklos Szeredi { 237a6ff2bc0SAmir Goldstein struct ovl_entry *oe = OVL_E(dentry); 238bbb1e54dSMiklos Szeredi 239*5522c9c7SAmir Goldstein return ovl_numlower(oe) ? ovl_lowerstack(oe)->dentry : NULL; 240bbb1e54dSMiklos Szeredi } 241bbb1e54dSMiklos Szeredi 24213464165SMiklos Szeredi const struct ovl_layer *ovl_layer_lower(struct dentry *dentry) 243da309e8cSAmir Goldstein { 244a6ff2bc0SAmir Goldstein struct ovl_entry *oe = OVL_E(dentry); 245da309e8cSAmir Goldstein 246*5522c9c7SAmir Goldstein return ovl_numlower(oe) ? ovl_lowerstack(oe)->layer : NULL; 247da309e8cSAmir Goldstein } 248da309e8cSAmir Goldstein 249647d253fSVivek Goyal /* 250647d253fSVivek Goyal * ovl_dentry_lower() could return either a data dentry or metacopy dentry 251597534e7SXiong Zhenwu * depending on what is stored in lowerstack[0]. At times we need to find 252647d253fSVivek Goyal * lower dentry which has data (and not metacopy dentry). This helper 253647d253fSVivek Goyal * returns the lower data dentry. 254647d253fSVivek Goyal */ 255647d253fSVivek Goyal struct dentry *ovl_dentry_lowerdata(struct dentry *dentry) 256647d253fSVivek Goyal { 257a6ff2bc0SAmir Goldstein struct ovl_entry *oe = OVL_E(dentry); 258647d253fSVivek Goyal 259*5522c9c7SAmir Goldstein return ovl_numlower(oe) ? 260*5522c9c7SAmir Goldstein ovl_lowerstack(oe)[ovl_numlower(oe) - 1].dentry : NULL; 261647d253fSVivek Goyal } 262647d253fSVivek Goyal 263bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_real(struct dentry *dentry) 264bbb1e54dSMiklos Szeredi { 26509d8b586SMiklos Szeredi return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry); 266bbb1e54dSMiklos Szeredi } 267bbb1e54dSMiklos Szeredi 2681d88f183SMiklos Szeredi struct dentry *ovl_i_dentry_upper(struct inode *inode) 2691d88f183SMiklos Szeredi { 2701d88f183SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(inode)); 2711d88f183SMiklos Szeredi } 2721d88f183SMiklos Szeredi 273b2dd05f1SZhihao Cheng struct inode *ovl_i_path_real(struct inode *inode, struct path *path) 274ffa5723cSAmir Goldstein { 275ffa5723cSAmir Goldstein path->dentry = ovl_i_dentry_upper(inode); 276ffa5723cSAmir Goldstein if (!path->dentry) { 277ffa5723cSAmir Goldstein path->dentry = OVL_I(inode)->lowerpath.dentry; 278ffa5723cSAmir Goldstein path->mnt = OVL_I(inode)->lowerpath.layer->mnt; 279ffa5723cSAmir Goldstein } else { 280ffa5723cSAmir Goldstein path->mnt = ovl_upper_mnt(OVL_FS(inode->i_sb)); 281ffa5723cSAmir Goldstein } 282b2dd05f1SZhihao Cheng 283b2dd05f1SZhihao Cheng return path->dentry ? d_inode_rcu(path->dentry) : NULL; 284ffa5723cSAmir Goldstein } 285ffa5723cSAmir Goldstein 28609d8b586SMiklos Szeredi struct inode *ovl_inode_upper(struct inode *inode) 28725b7713aSMiklos Szeredi { 2881d88f183SMiklos Szeredi struct dentry *upperdentry = ovl_i_dentry_upper(inode); 28925b7713aSMiklos Szeredi 29009d8b586SMiklos Szeredi return upperdentry ? d_inode(upperdentry) : NULL; 29125b7713aSMiklos Szeredi } 29225b7713aSMiklos Szeredi 29309d8b586SMiklos Szeredi struct inode *ovl_inode_lower(struct inode *inode) 29409d8b586SMiklos Szeredi { 295ffa5723cSAmir Goldstein struct dentry *lowerdentry = OVL_I(inode)->lowerpath.dentry; 296ffa5723cSAmir Goldstein 297ffa5723cSAmir Goldstein return lowerdentry ? d_inode(lowerdentry) : NULL; 29809d8b586SMiklos Szeredi } 29909d8b586SMiklos Szeredi 30009d8b586SMiklos Szeredi struct inode *ovl_inode_real(struct inode *inode) 30109d8b586SMiklos Szeredi { 30209d8b586SMiklos Szeredi return ovl_inode_upper(inode) ?: ovl_inode_lower(inode); 30309d8b586SMiklos Szeredi } 30409d8b586SMiklos Szeredi 3052664bd08SVivek Goyal /* Return inode which contains lower data. Do not return metacopy */ 3062664bd08SVivek Goyal struct inode *ovl_inode_lowerdata(struct inode *inode) 3072664bd08SVivek Goyal { 3082664bd08SVivek Goyal if (WARN_ON(!S_ISREG(inode->i_mode))) 3092664bd08SVivek Goyal return NULL; 3102664bd08SVivek Goyal 3112664bd08SVivek Goyal return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode); 3122664bd08SVivek Goyal } 31309d8b586SMiklos Szeredi 3144823d49cSVivek Goyal /* Return real inode which contains data. Does not return metacopy inode */ 3154823d49cSVivek Goyal struct inode *ovl_inode_realdata(struct inode *inode) 3164823d49cSVivek Goyal { 3174823d49cSVivek Goyal struct inode *upperinode; 3184823d49cSVivek Goyal 3194823d49cSVivek Goyal upperinode = ovl_inode_upper(inode); 3204823d49cSVivek Goyal if (upperinode && ovl_has_upperdata(inode)) 3214823d49cSVivek Goyal return upperinode; 3224823d49cSVivek Goyal 3234823d49cSVivek Goyal return ovl_inode_lowerdata(inode); 3244823d49cSVivek Goyal } 3254823d49cSVivek Goyal 3264edb83bbSMiklos Szeredi struct ovl_dir_cache *ovl_dir_cache(struct inode *inode) 327bbb1e54dSMiklos Szeredi { 3284edb83bbSMiklos Szeredi return OVL_I(inode)->cache; 329bbb1e54dSMiklos Szeredi } 330bbb1e54dSMiklos Szeredi 3314edb83bbSMiklos Szeredi void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache) 332bbb1e54dSMiklos Szeredi { 3334edb83bbSMiklos Szeredi OVL_I(inode)->cache = cache; 334bbb1e54dSMiklos Szeredi } 335bbb1e54dSMiklos Szeredi 336c62520a8SAmir Goldstein void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry) 337c62520a8SAmir Goldstein { 338a6ff2bc0SAmir Goldstein set_bit(flag, OVL_E_FLAGS(dentry)); 339c62520a8SAmir Goldstein } 340c62520a8SAmir Goldstein 341c62520a8SAmir Goldstein void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry) 342c62520a8SAmir Goldstein { 343a6ff2bc0SAmir Goldstein clear_bit(flag, OVL_E_FLAGS(dentry)); 344c62520a8SAmir Goldstein } 345c62520a8SAmir Goldstein 346c62520a8SAmir Goldstein bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry) 347c62520a8SAmir Goldstein { 348a6ff2bc0SAmir Goldstein return test_bit(flag, OVL_E_FLAGS(dentry)); 349c62520a8SAmir Goldstein } 350c62520a8SAmir Goldstein 351bbb1e54dSMiklos Szeredi bool ovl_dentry_is_opaque(struct dentry *dentry) 352bbb1e54dSMiklos Szeredi { 353c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_OPAQUE, dentry); 354bbb1e54dSMiklos Szeredi } 355bbb1e54dSMiklos Szeredi 356bbb1e54dSMiklos Szeredi bool ovl_dentry_is_whiteout(struct dentry *dentry) 357bbb1e54dSMiklos Szeredi { 358bbb1e54dSMiklos Szeredi return !dentry->d_inode && ovl_dentry_is_opaque(dentry); 359bbb1e54dSMiklos Szeredi } 360bbb1e54dSMiklos Szeredi 3615cf5b477SMiklos Szeredi void ovl_dentry_set_opaque(struct dentry *dentry) 362bbb1e54dSMiklos Szeredi { 363c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_OPAQUE, dentry); 364bbb1e54dSMiklos Szeredi } 365bbb1e54dSMiklos Szeredi 36655acc661SMiklos Szeredi /* 367aa3ff3c1SAmir Goldstein * For hard links and decoded file handles, it's possible for ovl_dentry_upper() 368aa3ff3c1SAmir Goldstein * to return positive, while there's no actual upper alias for the inode. 369aa3ff3c1SAmir Goldstein * Copy up code needs to know about the existence of the upper alias, so it 370aa3ff3c1SAmir Goldstein * can't use ovl_dentry_upper(). 37155acc661SMiklos Szeredi */ 37255acc661SMiklos Szeredi bool ovl_dentry_has_upper_alias(struct dentry *dentry) 37355acc661SMiklos Szeredi { 374c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_UPPER_ALIAS, dentry); 37555acc661SMiklos Szeredi } 37655acc661SMiklos Szeredi 37755acc661SMiklos Szeredi void ovl_dentry_set_upper_alias(struct dentry *dentry) 37855acc661SMiklos Szeredi { 379c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_UPPER_ALIAS, dentry); 38055acc661SMiklos Szeredi } 38155acc661SMiklos Szeredi 3820c288874SVivek Goyal static bool ovl_should_check_upperdata(struct inode *inode) 3830c288874SVivek Goyal { 3840c288874SVivek Goyal if (!S_ISREG(inode->i_mode)) 3850c288874SVivek Goyal return false; 3860c288874SVivek Goyal 3870c288874SVivek Goyal if (!ovl_inode_lower(inode)) 3880c288874SVivek Goyal return false; 3890c288874SVivek Goyal 3900c288874SVivek Goyal return true; 3910c288874SVivek Goyal } 3920c288874SVivek Goyal 3930c288874SVivek Goyal bool ovl_has_upperdata(struct inode *inode) 3940c288874SVivek Goyal { 3950c288874SVivek Goyal if (!ovl_should_check_upperdata(inode)) 3960c288874SVivek Goyal return true; 3970c288874SVivek Goyal 3980c288874SVivek Goyal if (!ovl_test_flag(OVL_UPPERDATA, inode)) 3990c288874SVivek Goyal return false; 4000c288874SVivek Goyal /* 4010c288874SVivek Goyal * Pairs with smp_wmb() in ovl_set_upperdata(). Main user of 4020c288874SVivek Goyal * ovl_has_upperdata() is ovl_copy_up_meta_inode_data(). Make sure 4030c288874SVivek Goyal * if setting of OVL_UPPERDATA is visible, then effects of writes 4040c288874SVivek Goyal * before that are visible too. 4050c288874SVivek Goyal */ 4060c288874SVivek Goyal smp_rmb(); 4070c288874SVivek Goyal return true; 4080c288874SVivek Goyal } 4090c288874SVivek Goyal 4100c288874SVivek Goyal void ovl_set_upperdata(struct inode *inode) 4110c288874SVivek Goyal { 4120c288874SVivek Goyal /* 4130c288874SVivek Goyal * Pairs with smp_rmb() in ovl_has_upperdata(). Make sure 4140c288874SVivek Goyal * if OVL_UPPERDATA flag is visible, then effects of write operations 4150c288874SVivek Goyal * before it are visible as well. 4160c288874SVivek Goyal */ 4170c288874SVivek Goyal smp_wmb(); 4180c288874SVivek Goyal ovl_set_flag(OVL_UPPERDATA, inode); 4190c288874SVivek Goyal } 4200c288874SVivek Goyal 4210c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 4220c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags) 4230c288874SVivek Goyal { 4240c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 4250c288874SVivek Goyal return false; 4260c288874SVivek Goyal 4270c288874SVivek Goyal return !ovl_test_flag(OVL_UPPERDATA, d_inode(dentry)); 4280c288874SVivek Goyal } 4290c288874SVivek Goyal 4300c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags) 4310c288874SVivek Goyal { 4320c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 4330c288874SVivek Goyal return false; 4340c288874SVivek Goyal 4350c288874SVivek Goyal return !ovl_has_upperdata(d_inode(dentry)); 4360c288874SVivek Goyal } 4370c288874SVivek Goyal 438a6c60655SMiklos Szeredi bool ovl_redirect_dir(struct super_block *sb) 439a6c60655SMiklos Szeredi { 440a6c60655SMiklos Szeredi struct ovl_fs *ofs = sb->s_fs_info; 441a6c60655SMiklos Szeredi 44221a22878SAmir Goldstein return ofs->config.redirect_dir && !ofs->noxattr; 443a6c60655SMiklos Szeredi } 444a6c60655SMiklos Szeredi 445a6c60655SMiklos Szeredi const char *ovl_dentry_get_redirect(struct dentry *dentry) 446a6c60655SMiklos Szeredi { 447cf31c463SMiklos Szeredi return OVL_I(d_inode(dentry))->redirect; 448a6c60655SMiklos Szeredi } 449a6c60655SMiklos Szeredi 450a6c60655SMiklos Szeredi void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect) 451a6c60655SMiklos Szeredi { 452cf31c463SMiklos Szeredi struct ovl_inode *oi = OVL_I(d_inode(dentry)); 453a6c60655SMiklos Szeredi 454cf31c463SMiklos Szeredi kfree(oi->redirect); 455cf31c463SMiklos Szeredi oi->redirect = redirect; 456a6c60655SMiklos Szeredi } 457a6c60655SMiklos Szeredi 45809d8b586SMiklos Szeredi void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) 459bbb1e54dSMiklos Szeredi { 46009d8b586SMiklos Szeredi struct inode *upperinode = d_inode(upperdentry); 461e6d2ebddSMiklos Szeredi 46209d8b586SMiklos Szeredi WARN_ON(OVL_I(inode)->__upperdentry); 46309d8b586SMiklos Szeredi 46425b7713aSMiklos Szeredi /* 46509d8b586SMiklos Szeredi * Make sure upperdentry is consistent before making it visible 46625b7713aSMiklos Szeredi */ 46725b7713aSMiklos Szeredi smp_wmb(); 46809d8b586SMiklos Szeredi OVL_I(inode)->__upperdentry = upperdentry; 46931747edaSAmir Goldstein if (inode_unhashed(inode)) { 47025b7713aSMiklos Szeredi inode->i_private = upperinode; 471bbb1e54dSMiklos Szeredi __insert_inode_hash(inode, (unsigned long) upperinode); 472bbb1e54dSMiklos Szeredi } 47325b7713aSMiklos Szeredi } 474bbb1e54dSMiklos Szeredi 47565cd913eSAmir Goldstein static void ovl_dir_version_inc(struct dentry *dentry, bool impurity) 476bbb1e54dSMiklos Szeredi { 47704a01ac7SMiklos Szeredi struct inode *inode = d_inode(dentry); 478bbb1e54dSMiklos Szeredi 47904a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 48065cd913eSAmir Goldstein WARN_ON(!d_is_dir(dentry)); 4814edb83bbSMiklos Szeredi /* 48265cd913eSAmir Goldstein * Version is used by readdir code to keep cache consistent. 48365cd913eSAmir Goldstein * For merge dirs (or dirs with origin) all changes need to be noted. 48465cd913eSAmir Goldstein * For non-merge dirs, cache contains only impure entries (i.e. ones 48565cd913eSAmir Goldstein * which have been copied up and have origins), so only need to note 48665cd913eSAmir Goldstein * changes to impure entries. 4874edb83bbSMiklos Szeredi */ 4881fa9c5c5SMiklos Szeredi if (!ovl_dir_is_real(inode) || impurity) 48904a01ac7SMiklos Szeredi OVL_I(inode)->version++; 490bbb1e54dSMiklos Szeredi } 491bbb1e54dSMiklos Szeredi 492d9854c87SMiklos Szeredi void ovl_dir_modified(struct dentry *dentry, bool impurity) 493d9854c87SMiklos Szeredi { 494d9854c87SMiklos Szeredi /* Copy mtime/ctime */ 4952878dffcSChristian Brauner ovl_copyattr(d_inode(dentry)); 496d9854c87SMiklos Szeredi 49765cd913eSAmir Goldstein ovl_dir_version_inc(dentry, impurity); 498d9854c87SMiklos Szeredi } 499d9854c87SMiklos Szeredi 5001fa9c5c5SMiklos Szeredi u64 ovl_inode_version_get(struct inode *inode) 501bbb1e54dSMiklos Szeredi { 50204a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 50304a01ac7SMiklos Szeredi return OVL_I(inode)->version; 504bbb1e54dSMiklos Szeredi } 505bbb1e54dSMiklos Szeredi 506bbb1e54dSMiklos Szeredi bool ovl_is_whiteout(struct dentry *dentry) 507bbb1e54dSMiklos Szeredi { 508bbb1e54dSMiklos Szeredi struct inode *inode = dentry->d_inode; 509bbb1e54dSMiklos Szeredi 510bbb1e54dSMiklos Szeredi return inode && IS_WHITEOUT(inode); 511bbb1e54dSMiklos Szeredi } 512bbb1e54dSMiklos Szeredi 5132d343087SAl Viro struct file *ovl_path_open(const struct path *path, int flags) 514bbb1e54dSMiklos Szeredi { 51556230d95SMiklos Szeredi struct inode *inode = d_inode(path->dentry); 5164609e1f1SChristian Brauner struct mnt_idmap *real_idmap = mnt_idmap(path->mnt); 51756230d95SMiklos Szeredi int err, acc_mode; 51856230d95SMiklos Szeredi 51956230d95SMiklos Szeredi if (flags & ~(O_ACCMODE | O_LARGEFILE)) 52056230d95SMiklos Szeredi BUG(); 52156230d95SMiklos Szeredi 52256230d95SMiklos Szeredi switch (flags & O_ACCMODE) { 52356230d95SMiklos Szeredi case O_RDONLY: 52456230d95SMiklos Szeredi acc_mode = MAY_READ; 52556230d95SMiklos Szeredi break; 52656230d95SMiklos Szeredi case O_WRONLY: 52756230d95SMiklos Szeredi acc_mode = MAY_WRITE; 52856230d95SMiklos Szeredi break; 52956230d95SMiklos Szeredi default: 53056230d95SMiklos Szeredi BUG(); 53156230d95SMiklos Szeredi } 53256230d95SMiklos Szeredi 5334609e1f1SChristian Brauner err = inode_permission(real_idmap, inode, acc_mode | MAY_OPEN); 53456230d95SMiklos Szeredi if (err) 53556230d95SMiklos Szeredi return ERR_PTR(err); 53656230d95SMiklos Szeredi 53756230d95SMiklos Szeredi /* O_NOATIME is an optimization, don't fail if not permitted */ 53801beba79SChristian Brauner if (inode_owner_or_capable(real_idmap, inode)) 53956230d95SMiklos Szeredi flags |= O_NOATIME; 54056230d95SMiklos Szeredi 54156230d95SMiklos Szeredi return dentry_open(path, flags, current_cred()); 542bbb1e54dSMiklos Szeredi } 54339d3d60aSAmir Goldstein 5440c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 5450c288874SVivek Goyal static bool ovl_already_copied_up_locked(struct dentry *dentry, int flags) 5460c288874SVivek Goyal { 5470c288874SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 5480c288874SVivek Goyal 5490c288874SVivek Goyal if (ovl_dentry_upper(dentry) && 5500c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 5510c288874SVivek Goyal !ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 5520c288874SVivek Goyal return true; 5530c288874SVivek Goyal 5540c288874SVivek Goyal return false; 5550c288874SVivek Goyal } 5560c288874SVivek Goyal 5570c288874SVivek Goyal bool ovl_already_copied_up(struct dentry *dentry, int flags) 5582002df85SVivek Goyal { 5592002df85SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 5602002df85SVivek Goyal 5612002df85SVivek Goyal /* 5622002df85SVivek Goyal * Check if copy-up has happened as well as for upper alias (in 5632002df85SVivek Goyal * case of hard links) is there. 5642002df85SVivek Goyal * 5652002df85SVivek Goyal * Both checks are lockless: 5662002df85SVivek Goyal * - false negatives: will recheck under oi->lock 5672002df85SVivek Goyal * - false positives: 5682002df85SVivek Goyal * + ovl_dentry_upper() uses memory barriers to ensure the 5692002df85SVivek Goyal * upper dentry is up-to-date 5702002df85SVivek Goyal * + ovl_dentry_has_upper_alias() relies on locking of 5712002df85SVivek Goyal * upper parent i_rwsem to prevent reordering copy-up 5722002df85SVivek Goyal * with rename. 5732002df85SVivek Goyal */ 5742002df85SVivek Goyal if (ovl_dentry_upper(dentry) && 5750c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 5760c288874SVivek Goyal !ovl_dentry_needs_data_copy_up(dentry, flags)) 5772002df85SVivek Goyal return true; 5782002df85SVivek Goyal 5792002df85SVivek Goyal return false; 5802002df85SVivek Goyal } 5812002df85SVivek Goyal 5820c288874SVivek Goyal int ovl_copy_up_start(struct dentry *dentry, int flags) 58339d3d60aSAmir Goldstein { 5841e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 58539d3d60aSAmir Goldstein int err; 58639d3d60aSAmir Goldstein 587531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 5880c288874SVivek Goyal if (!err && ovl_already_copied_up_locked(dentry, flags)) { 58939d3d60aSAmir Goldstein err = 1; /* Already copied up */ 5901e92e307SAmir Goldstein ovl_inode_unlock(inode); 59139d3d60aSAmir Goldstein } 59239d3d60aSAmir Goldstein 59339d3d60aSAmir Goldstein return err; 59439d3d60aSAmir Goldstein } 59539d3d60aSAmir Goldstein 59639d3d60aSAmir Goldstein void ovl_copy_up_end(struct dentry *dentry) 59739d3d60aSAmir Goldstein { 5981e92e307SAmir Goldstein ovl_inode_unlock(d_inode(dentry)); 59939d3d60aSAmir Goldstein } 60082b749b2SAmir Goldstein 6012d343087SAl Viro bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path) 602b79e05aaSAmir Goldstein { 603b79e05aaSAmir Goldstein int res; 604b79e05aaSAmir Goldstein 605dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_ORIGIN, NULL, 0); 606b79e05aaSAmir Goldstein 607b79e05aaSAmir Goldstein /* Zero size value means "copied up but origin unknown" */ 608b79e05aaSAmir Goldstein if (res >= 0) 609b79e05aaSAmir Goldstein return true; 610b79e05aaSAmir Goldstein 611b79e05aaSAmir Goldstein return false; 612b79e05aaSAmir Goldstein } 613b79e05aaSAmir Goldstein 6142d343087SAl Viro bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, 61543d193f8SMiklos Szeredi enum ovl_xattr ox) 616f3a15685SAmir Goldstein { 617f3a15685SAmir Goldstein int res; 618f3a15685SAmir Goldstein char val; 619f3a15685SAmir Goldstein 620dad7017aSChristian Brauner if (!d_is_dir(path->dentry)) 621f3a15685SAmir Goldstein return false; 622f3a15685SAmir Goldstein 623dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, ox, &val, 1); 624f3a15685SAmir Goldstein if (res == 1 && val == 'y') 625f3a15685SAmir Goldstein return true; 626f3a15685SAmir Goldstein 627f3a15685SAmir Goldstein return false; 628f3a15685SAmir Goldstein } 629f3a15685SAmir Goldstein 63043d193f8SMiklos Szeredi #define OVL_XATTR_OPAQUE_POSTFIX "opaque" 63143d193f8SMiklos Szeredi #define OVL_XATTR_REDIRECT_POSTFIX "redirect" 63243d193f8SMiklos Szeredi #define OVL_XATTR_ORIGIN_POSTFIX "origin" 63343d193f8SMiklos Szeredi #define OVL_XATTR_IMPURE_POSTFIX "impure" 63443d193f8SMiklos Szeredi #define OVL_XATTR_NLINK_POSTFIX "nlink" 63543d193f8SMiklos Szeredi #define OVL_XATTR_UPPER_POSTFIX "upper" 63643d193f8SMiklos Szeredi #define OVL_XATTR_METACOPY_POSTFIX "metacopy" 637096a218aSAmir Goldstein #define OVL_XATTR_PROTATTR_POSTFIX "protattr" 63843d193f8SMiklos Szeredi 63943d193f8SMiklos Szeredi #define OVL_XATTR_TAB_ENTRY(x) \ 6402d2f2d73SMiklos Szeredi [x] = { [false] = OVL_XATTR_TRUSTED_PREFIX x ## _POSTFIX, \ 6412d2f2d73SMiklos Szeredi [true] = OVL_XATTR_USER_PREFIX x ## _POSTFIX } 64243d193f8SMiklos Szeredi 6432d2f2d73SMiklos Szeredi const char *const ovl_xattr_table[][2] = { 64443d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_OPAQUE), 64543d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_REDIRECT), 64643d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_ORIGIN), 64743d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_IMPURE), 64843d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_NLINK), 64943d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_UPPER), 65043d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY), 651096a218aSAmir Goldstein OVL_XATTR_TAB_ENTRY(OVL_XATTR_PROTATTR), 65243d193f8SMiklos Szeredi }; 65343d193f8SMiklos Szeredi 654a0c236b1SAmir Goldstein int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 65543d193f8SMiklos Szeredi enum ovl_xattr ox, const void *value, size_t size, 65682b749b2SAmir Goldstein int xerr) 65782b749b2SAmir Goldstein { 65882b749b2SAmir Goldstein int err; 65982b749b2SAmir Goldstein 66082b749b2SAmir Goldstein if (ofs->noxattr) 66182b749b2SAmir Goldstein return xerr; 66282b749b2SAmir Goldstein 663c914c0e2SAmir Goldstein err = ovl_setxattr(ofs, upperdentry, ox, value, size); 66482b749b2SAmir Goldstein 66582b749b2SAmir Goldstein if (err == -EOPNOTSUPP) { 66643d193f8SMiklos Szeredi pr_warn("cannot set %s xattr on upper\n", ovl_xattr(ofs, ox)); 66782b749b2SAmir Goldstein ofs->noxattr = true; 66882b749b2SAmir Goldstein return xerr; 66982b749b2SAmir Goldstein } 67082b749b2SAmir Goldstein 67182b749b2SAmir Goldstein return err; 67282b749b2SAmir Goldstein } 673f3a15685SAmir Goldstein 674f3a15685SAmir Goldstein int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry) 675f3a15685SAmir Goldstein { 676a0c236b1SAmir Goldstein struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 677f3a15685SAmir Goldstein int err; 678f3a15685SAmir Goldstein 67913c72075SMiklos Szeredi if (ovl_test_flag(OVL_IMPURE, d_inode(dentry))) 680f3a15685SAmir Goldstein return 0; 681f3a15685SAmir Goldstein 682f3a15685SAmir Goldstein /* 683f3a15685SAmir Goldstein * Do not fail when upper doesn't support xattrs. 684f3a15685SAmir Goldstein * Upper inodes won't have origin nor redirect xattr anyway. 685f3a15685SAmir Goldstein */ 686a0c236b1SAmir Goldstein err = ovl_check_setxattr(ofs, upperdentry, OVL_XATTR_IMPURE, "y", 1, 0); 687f3a15685SAmir Goldstein if (!err) 68813c72075SMiklos Szeredi ovl_set_flag(OVL_IMPURE, d_inode(dentry)); 689f3a15685SAmir Goldstein 690f3a15685SAmir Goldstein return err; 691f3a15685SAmir Goldstein } 69213c72075SMiklos Szeredi 693096a218aSAmir Goldstein 694096a218aSAmir Goldstein #define OVL_PROTATTR_MAX 32 /* Reserved for future flags */ 695096a218aSAmir Goldstein 696096a218aSAmir Goldstein void ovl_check_protattr(struct inode *inode, struct dentry *upper) 697096a218aSAmir Goldstein { 698096a218aSAmir Goldstein struct ovl_fs *ofs = OVL_FS(inode->i_sb); 699096a218aSAmir Goldstein u32 iflags = inode->i_flags & OVL_PROT_I_FLAGS_MASK; 700096a218aSAmir Goldstein char buf[OVL_PROTATTR_MAX+1]; 701096a218aSAmir Goldstein int res, n; 702096a218aSAmir Goldstein 703dad7017aSChristian Brauner res = ovl_getxattr_upper(ofs, upper, OVL_XATTR_PROTATTR, buf, 704096a218aSAmir Goldstein OVL_PROTATTR_MAX); 705096a218aSAmir Goldstein if (res < 0) 706096a218aSAmir Goldstein return; 707096a218aSAmir Goldstein 708096a218aSAmir Goldstein /* 709096a218aSAmir Goldstein * Initialize inode flags from overlay.protattr xattr and upper inode 710096a218aSAmir Goldstein * flags. If upper inode has those fileattr flags set (i.e. from old 711096a218aSAmir Goldstein * kernel), we do not clear them on ovl_get_inode(), but we will clear 712096a218aSAmir Goldstein * them on next fileattr_set(). 713096a218aSAmir Goldstein */ 714096a218aSAmir Goldstein for (n = 0; n < res; n++) { 715096a218aSAmir Goldstein if (buf[n] == 'a') 716096a218aSAmir Goldstein iflags |= S_APPEND; 717096a218aSAmir Goldstein else if (buf[n] == 'i') 718096a218aSAmir Goldstein iflags |= S_IMMUTABLE; 719096a218aSAmir Goldstein else 720096a218aSAmir Goldstein break; 721096a218aSAmir Goldstein } 722096a218aSAmir Goldstein 723096a218aSAmir Goldstein if (!res || n < res) { 724096a218aSAmir Goldstein pr_warn_ratelimited("incompatible overlay.protattr format (%pd2, len=%d)\n", 725096a218aSAmir Goldstein upper, res); 726096a218aSAmir Goldstein } else { 727096a218aSAmir Goldstein inode_set_flags(inode, iflags, OVL_PROT_I_FLAGS_MASK); 728096a218aSAmir Goldstein } 729096a218aSAmir Goldstein } 730096a218aSAmir Goldstein 731096a218aSAmir Goldstein int ovl_set_protattr(struct inode *inode, struct dentry *upper, 732096a218aSAmir Goldstein struct fileattr *fa) 733096a218aSAmir Goldstein { 734096a218aSAmir Goldstein struct ovl_fs *ofs = OVL_FS(inode->i_sb); 735096a218aSAmir Goldstein char buf[OVL_PROTATTR_MAX]; 736096a218aSAmir Goldstein int len = 0, err = 0; 737096a218aSAmir Goldstein u32 iflags = 0; 738096a218aSAmir Goldstein 739096a218aSAmir Goldstein BUILD_BUG_ON(HWEIGHT32(OVL_PROT_FS_FLAGS_MASK) > OVL_PROTATTR_MAX); 740096a218aSAmir Goldstein 741096a218aSAmir Goldstein if (fa->flags & FS_APPEND_FL) { 742096a218aSAmir Goldstein buf[len++] = 'a'; 743096a218aSAmir Goldstein iflags |= S_APPEND; 744096a218aSAmir Goldstein } 745096a218aSAmir Goldstein if (fa->flags & FS_IMMUTABLE_FL) { 746096a218aSAmir Goldstein buf[len++] = 'i'; 747096a218aSAmir Goldstein iflags |= S_IMMUTABLE; 748096a218aSAmir Goldstein } 749096a218aSAmir Goldstein 750096a218aSAmir Goldstein /* 751096a218aSAmir Goldstein * Do not allow to set protection flags when upper doesn't support 752096a218aSAmir Goldstein * xattrs, because we do not set those fileattr flags on upper inode. 753096a218aSAmir Goldstein * Remove xattr if it exist and all protection flags are cleared. 754096a218aSAmir Goldstein */ 755096a218aSAmir Goldstein if (len) { 756096a218aSAmir Goldstein err = ovl_check_setxattr(ofs, upper, OVL_XATTR_PROTATTR, 757096a218aSAmir Goldstein buf, len, -EPERM); 758096a218aSAmir Goldstein } else if (inode->i_flags & OVL_PROT_I_FLAGS_MASK) { 759c914c0e2SAmir Goldstein err = ovl_removexattr(ofs, upper, OVL_XATTR_PROTATTR); 760096a218aSAmir Goldstein if (err == -EOPNOTSUPP || err == -ENODATA) 761096a218aSAmir Goldstein err = 0; 762096a218aSAmir Goldstein } 763096a218aSAmir Goldstein if (err) 764096a218aSAmir Goldstein return err; 765096a218aSAmir Goldstein 766096a218aSAmir Goldstein inode_set_flags(inode, iflags, OVL_PROT_I_FLAGS_MASK); 767096a218aSAmir Goldstein 768096a218aSAmir Goldstein /* Mask out the fileattr flags that should not be set in upper inode */ 769096a218aSAmir Goldstein fa->flags &= ~OVL_PROT_FS_FLAGS_MASK; 770096a218aSAmir Goldstein fa->fsx_xflags &= ~OVL_PROT_FSX_FLAGS_MASK; 771096a218aSAmir Goldstein 772096a218aSAmir Goldstein return 0; 773096a218aSAmir Goldstein } 774096a218aSAmir Goldstein 775ad0af710SAmir Goldstein /** 776ad0af710SAmir Goldstein * Caller must hold a reference to inode to prevent it from being freed while 777ad0af710SAmir Goldstein * it is marked inuse. 778ad0af710SAmir Goldstein */ 779ad0af710SAmir Goldstein bool ovl_inuse_trylock(struct dentry *dentry) 780ad0af710SAmir Goldstein { 781ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 782ad0af710SAmir Goldstein bool locked = false; 783ad0af710SAmir Goldstein 784ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 785ad0af710SAmir Goldstein if (!(inode->i_state & I_OVL_INUSE)) { 786ad0af710SAmir Goldstein inode->i_state |= I_OVL_INUSE; 787ad0af710SAmir Goldstein locked = true; 788ad0af710SAmir Goldstein } 789ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 790ad0af710SAmir Goldstein 791ad0af710SAmir Goldstein return locked; 792ad0af710SAmir Goldstein } 793ad0af710SAmir Goldstein 794ad0af710SAmir Goldstein void ovl_inuse_unlock(struct dentry *dentry) 795ad0af710SAmir Goldstein { 796ad0af710SAmir Goldstein if (dentry) { 797ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 798ad0af710SAmir Goldstein 799ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 800ad0af710SAmir Goldstein WARN_ON(!(inode->i_state & I_OVL_INUSE)); 801ad0af710SAmir Goldstein inode->i_state &= ~I_OVL_INUSE; 802ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 803ad0af710SAmir Goldstein } 804ad0af710SAmir Goldstein } 8055f8415d6SAmir Goldstein 806146d62e5SAmir Goldstein bool ovl_is_inuse(struct dentry *dentry) 807146d62e5SAmir Goldstein { 808146d62e5SAmir Goldstein struct inode *inode = d_inode(dentry); 809146d62e5SAmir Goldstein bool inuse; 810146d62e5SAmir Goldstein 811146d62e5SAmir Goldstein spin_lock(&inode->i_lock); 812146d62e5SAmir Goldstein inuse = (inode->i_state & I_OVL_INUSE); 813146d62e5SAmir Goldstein spin_unlock(&inode->i_lock); 814146d62e5SAmir Goldstein 815146d62e5SAmir Goldstein return inuse; 816146d62e5SAmir Goldstein } 817146d62e5SAmir Goldstein 81824b33ee1SAmir Goldstein /* 81924b33ee1SAmir Goldstein * Does this overlay dentry need to be indexed on copy up? 82024b33ee1SAmir Goldstein */ 82124b33ee1SAmir Goldstein bool ovl_need_index(struct dentry *dentry) 82224b33ee1SAmir Goldstein { 82324b33ee1SAmir Goldstein struct dentry *lower = ovl_dentry_lower(dentry); 82424b33ee1SAmir Goldstein 82524b33ee1SAmir Goldstein if (!lower || !ovl_indexdir(dentry->d_sb)) 82624b33ee1SAmir Goldstein return false; 82724b33ee1SAmir Goldstein 828fbd2d207SAmir Goldstein /* Index all files for NFS export and consistency verification */ 829016b720fSAmir Goldstein if (ovl_index_all(dentry->d_sb)) 830fbd2d207SAmir Goldstein return true; 831fbd2d207SAmir Goldstein 83224b33ee1SAmir Goldstein /* Index only lower hardlinks on copy up */ 83324b33ee1SAmir Goldstein if (!d_is_dir(lower) && d_inode(lower)->i_nlink > 1) 83424b33ee1SAmir Goldstein return true; 83524b33ee1SAmir Goldstein 83624b33ee1SAmir Goldstein return false; 83724b33ee1SAmir Goldstein } 83824b33ee1SAmir Goldstein 8399f4ec904SAmir Goldstein /* Caller must hold OVL_I(inode)->lock */ 840caf70cb2SAmir Goldstein static void ovl_cleanup_index(struct dentry *dentry) 841caf70cb2SAmir Goldstein { 8421cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 843e7dd0e71SAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 844e7dd0e71SAmir Goldstein struct inode *dir = indexdir->d_inode; 845caf70cb2SAmir Goldstein struct dentry *lowerdentry = ovl_dentry_lower(dentry); 846caf70cb2SAmir Goldstein struct dentry *upperdentry = ovl_dentry_upper(dentry); 847caf70cb2SAmir Goldstein struct dentry *index = NULL; 848caf70cb2SAmir Goldstein struct inode *inode; 84963e13252SAmir Goldstein struct qstr name = { }; 850caf70cb2SAmir Goldstein int err; 851caf70cb2SAmir Goldstein 8521cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, lowerdentry, &name); 853caf70cb2SAmir Goldstein if (err) 854caf70cb2SAmir Goldstein goto fail; 855caf70cb2SAmir Goldstein 856caf70cb2SAmir Goldstein inode = d_inode(upperdentry); 85789a17556SAmir Goldstein if (!S_ISDIR(inode->i_mode) && inode->i_nlink != 1) { 8581bd0a3aeSlijiazi pr_warn_ratelimited("cleanup linked index (%pd2, ino=%lu, nlink=%u)\n", 859caf70cb2SAmir Goldstein upperdentry, inode->i_ino, inode->i_nlink); 860caf70cb2SAmir Goldstein /* 861caf70cb2SAmir Goldstein * We either have a bug with persistent union nlink or a lower 862caf70cb2SAmir Goldstein * hardlink was added while overlay is mounted. Adding a lower 863caf70cb2SAmir Goldstein * hardlink and then unlinking all overlay hardlinks would drop 864caf70cb2SAmir Goldstein * overlay nlink to zero before all upper inodes are unlinked. 865caf70cb2SAmir Goldstein * As a safety measure, when that situation is detected, set 866caf70cb2SAmir Goldstein * the overlay nlink to the index inode nlink minus one for the 867caf70cb2SAmir Goldstein * index entry itself. 868caf70cb2SAmir Goldstein */ 869caf70cb2SAmir Goldstein set_nlink(d_inode(dentry), inode->i_nlink - 1); 870caf70cb2SAmir Goldstein ovl_set_nlink_upper(dentry); 871caf70cb2SAmir Goldstein goto out; 872caf70cb2SAmir Goldstein } 873caf70cb2SAmir Goldstein 874caf70cb2SAmir Goldstein inode_lock_nested(dir, I_MUTEX_PARENT); 87522f289ceSChristian Brauner index = ovl_lookup_upper(ofs, name.name, indexdir, name.len); 876caf70cb2SAmir Goldstein err = PTR_ERR(index); 877e7dd0e71SAmir Goldstein if (IS_ERR(index)) { 8789f4ec904SAmir Goldstein index = NULL; 879e7dd0e71SAmir Goldstein } else if (ovl_index_all(dentry->d_sb)) { 880e7dd0e71SAmir Goldstein /* Whiteout orphan index to block future open by handle */ 881c21c839bSChengguang Xu err = ovl_cleanup_and_whiteout(OVL_FS(dentry->d_sb), 882c21c839bSChengguang Xu dir, index); 883e7dd0e71SAmir Goldstein } else { 884e7dd0e71SAmir Goldstein /* Cleanup orphan index entries */ 885576bb263SChristian Brauner err = ovl_cleanup(ofs, dir, index); 886e7dd0e71SAmir Goldstein } 8879f4ec904SAmir Goldstein 888caf70cb2SAmir Goldstein inode_unlock(dir); 889caf70cb2SAmir Goldstein if (err) 890caf70cb2SAmir Goldstein goto fail; 891caf70cb2SAmir Goldstein 892caf70cb2SAmir Goldstein out: 89363e13252SAmir Goldstein kfree(name.name); 894caf70cb2SAmir Goldstein dput(index); 895caf70cb2SAmir Goldstein return; 896caf70cb2SAmir Goldstein 897caf70cb2SAmir Goldstein fail: 8981bd0a3aeSlijiazi pr_err("cleanup index of '%pd2' failed (%i)\n", dentry, err); 899caf70cb2SAmir Goldstein goto out; 900caf70cb2SAmir Goldstein } 901caf70cb2SAmir Goldstein 9025f8415d6SAmir Goldstein /* 9035f8415d6SAmir Goldstein * Operations that change overlay inode and upper inode nlink need to be 9045f8415d6SAmir Goldstein * synchronized with copy up for persistent nlink accounting. 9055f8415d6SAmir Goldstein */ 9060e32992fSAmir Goldstein int ovl_nlink_start(struct dentry *dentry) 9075f8415d6SAmir Goldstein { 9081e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 9095f8415d6SAmir Goldstein const struct cred *old_cred; 9105f8415d6SAmir Goldstein int err; 9115f8415d6SAmir Goldstein 9121e92e307SAmir Goldstein if (WARN_ON(!inode)) 9130e32992fSAmir Goldstein return -ENOENT; 9145f8415d6SAmir Goldstein 9155f8415d6SAmir Goldstein /* 9165f8415d6SAmir Goldstein * With inodes index is enabled, we store the union overlay nlink 91724b33ee1SAmir Goldstein * in an xattr on the index inode. When whiting out an indexed lower, 9185f8415d6SAmir Goldstein * we need to decrement the overlay persistent nlink, but before the 9195f8415d6SAmir Goldstein * first copy up, we have no upper index inode to store the xattr. 9205f8415d6SAmir Goldstein * 92124b33ee1SAmir Goldstein * As a workaround, before whiteout/rename over an indexed lower, 9225f8415d6SAmir Goldstein * copy up to create the upper index. Creating the upper index will 9235f8415d6SAmir Goldstein * initialize the overlay nlink, so it could be dropped if unlink 9245f8415d6SAmir Goldstein * or rename succeeds. 9255f8415d6SAmir Goldstein * 9265f8415d6SAmir Goldstein * TODO: implement metadata only index copy up when called with 9275f8415d6SAmir Goldstein * ovl_copy_up_flags(dentry, O_PATH). 9285f8415d6SAmir Goldstein */ 92924b33ee1SAmir Goldstein if (ovl_need_index(dentry) && !ovl_dentry_has_upper_alias(dentry)) { 9305f8415d6SAmir Goldstein err = ovl_copy_up(dentry); 9315f8415d6SAmir Goldstein if (err) 9325f8415d6SAmir Goldstein return err; 9335f8415d6SAmir Goldstein } 9345f8415d6SAmir Goldstein 935531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 9365f8415d6SAmir Goldstein if (err) 9375f8415d6SAmir Goldstein return err; 9385f8415d6SAmir Goldstein 9391e92e307SAmir Goldstein if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, inode)) 9405f8415d6SAmir Goldstein goto out; 9415f8415d6SAmir Goldstein 9425f8415d6SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 9435f8415d6SAmir Goldstein /* 9445f8415d6SAmir Goldstein * The overlay inode nlink should be incremented/decremented IFF the 9455f8415d6SAmir Goldstein * upper operation succeeds, along with nlink change of upper inode. 9465f8415d6SAmir Goldstein * Therefore, before link/unlink/rename, we store the union nlink 9475f8415d6SAmir Goldstein * value relative to the upper inode nlink in an upper inode xattr. 9485f8415d6SAmir Goldstein */ 9495f8415d6SAmir Goldstein err = ovl_set_nlink_upper(dentry); 9505f8415d6SAmir Goldstein revert_creds(old_cred); 9515f8415d6SAmir Goldstein 9525f8415d6SAmir Goldstein out: 9535f8415d6SAmir Goldstein if (err) 9541e92e307SAmir Goldstein ovl_inode_unlock(inode); 9555f8415d6SAmir Goldstein 9565f8415d6SAmir Goldstein return err; 9575f8415d6SAmir Goldstein } 9585f8415d6SAmir Goldstein 9590e32992fSAmir Goldstein void ovl_nlink_end(struct dentry *dentry) 9605f8415d6SAmir Goldstein { 9611e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 9621e92e307SAmir Goldstein 9631e92e307SAmir Goldstein if (ovl_test_flag(OVL_INDEX, inode) && inode->i_nlink == 0) { 964caf70cb2SAmir Goldstein const struct cred *old_cred; 965caf70cb2SAmir Goldstein 966caf70cb2SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 967caf70cb2SAmir Goldstein ovl_cleanup_index(dentry); 968caf70cb2SAmir Goldstein revert_creds(old_cred); 969caf70cb2SAmir Goldstein } 970caf70cb2SAmir Goldstein 9711e92e307SAmir Goldstein ovl_inode_unlock(inode); 9725f8415d6SAmir Goldstein } 9735820dc08SAmir Goldstein 9745820dc08SAmir Goldstein int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir) 9755820dc08SAmir Goldstein { 9765820dc08SAmir Goldstein /* Workdir should not be the same as upperdir */ 9775820dc08SAmir Goldstein if (workdir == upperdir) 9785820dc08SAmir Goldstein goto err; 9795820dc08SAmir Goldstein 9805820dc08SAmir Goldstein /* Workdir should not be subdir of upperdir and vice versa */ 9815820dc08SAmir Goldstein if (lock_rename(workdir, upperdir) != NULL) 9825820dc08SAmir Goldstein goto err_unlock; 9835820dc08SAmir Goldstein 9845820dc08SAmir Goldstein return 0; 9855820dc08SAmir Goldstein 9865820dc08SAmir Goldstein err_unlock: 9875820dc08SAmir Goldstein unlock_rename(workdir, upperdir); 9885820dc08SAmir Goldstein err: 9891bd0a3aeSlijiazi pr_err("failed to lock workdir+upperdir\n"); 9905820dc08SAmir Goldstein return -EIO; 9915820dc08SAmir Goldstein } 9929d3dfea3SVivek Goyal 9939d3dfea3SVivek Goyal /* err < 0, 0 if no metacopy xattr, 1 if metacopy xattr found */ 9942d343087SAl Viro int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path) 9959d3dfea3SVivek Goyal { 9969d3dfea3SVivek Goyal int res; 9979d3dfea3SVivek Goyal 9989d3dfea3SVivek Goyal /* Only regular files can have metacopy xattr */ 999dad7017aSChristian Brauner if (!S_ISREG(d_inode(path->dentry)->i_mode)) 10009d3dfea3SVivek Goyal return 0; 10019d3dfea3SVivek Goyal 1002dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_METACOPY, NULL, 0); 10039d3dfea3SVivek Goyal if (res < 0) { 10049d3dfea3SVivek Goyal if (res == -ENODATA || res == -EOPNOTSUPP) 10059d3dfea3SVivek Goyal return 0; 100687b2c60cSMiklos Szeredi /* 100787b2c60cSMiklos Szeredi * getxattr on user.* may fail with EACCES in case there's no 100887b2c60cSMiklos Szeredi * read permission on the inode. Not much we can do, other than 100987b2c60cSMiklos Szeredi * tell the caller that this is not a metacopy inode. 101087b2c60cSMiklos Szeredi */ 101187b2c60cSMiklos Szeredi if (ofs->config.userxattr && res == -EACCES) 101287b2c60cSMiklos Szeredi return 0; 10139d3dfea3SVivek Goyal goto out; 10149d3dfea3SVivek Goyal } 10159d3dfea3SVivek Goyal 10169d3dfea3SVivek Goyal return 1; 10179d3dfea3SVivek Goyal out: 10181bd0a3aeSlijiazi pr_warn_ratelimited("failed to get metacopy (%i)\n", res); 10199d3dfea3SVivek Goyal return res; 10209d3dfea3SVivek Goyal } 102167d756c2SVivek Goyal 102267d756c2SVivek Goyal bool ovl_is_metacopy_dentry(struct dentry *dentry) 102367d756c2SVivek Goyal { 1024a6ff2bc0SAmir Goldstein struct ovl_entry *oe = OVL_E(dentry); 102567d756c2SVivek Goyal 102667d756c2SVivek Goyal if (!d_is_reg(dentry)) 102767d756c2SVivek Goyal return false; 102867d756c2SVivek Goyal 102967d756c2SVivek Goyal if (ovl_dentry_upper(dentry)) { 103067d756c2SVivek Goyal if (!ovl_has_upperdata(d_inode(dentry))) 103167d756c2SVivek Goyal return true; 103267d756c2SVivek Goyal return false; 103367d756c2SVivek Goyal } 103467d756c2SVivek Goyal 1035*5522c9c7SAmir Goldstein return (ovl_numlower(oe) > 1); 103667d756c2SVivek Goyal } 10370a2d0d3fSVivek Goyal 10382d343087SAl Viro char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding) 10390a2d0d3fSVivek Goyal { 10400a2d0d3fSVivek Goyal int res; 10410a2d0d3fSVivek Goyal char *s, *next, *buf = NULL; 10420a2d0d3fSVivek Goyal 1043dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_REDIRECT, NULL, 0); 104492f0d6c9SMiklos Szeredi if (res == -ENODATA || res == -EOPNOTSUPP) 10450a2d0d3fSVivek Goyal return NULL; 10460a2d0d3fSVivek Goyal if (res < 0) 104792f0d6c9SMiklos Szeredi goto fail; 104892f0d6c9SMiklos Szeredi if (res == 0) 104992f0d6c9SMiklos Szeredi goto invalid; 105092f0d6c9SMiklos Szeredi 105192f0d6c9SMiklos Szeredi buf = kzalloc(res + padding + 1, GFP_KERNEL); 105292f0d6c9SMiklos Szeredi if (!buf) 105392f0d6c9SMiklos Szeredi return ERR_PTR(-ENOMEM); 105492f0d6c9SMiklos Szeredi 1055dad7017aSChristian Brauner res = ovl_path_getxattr(ofs, path, OVL_XATTR_REDIRECT, buf, res); 105692f0d6c9SMiklos Szeredi if (res < 0) 105792f0d6c9SMiklos Szeredi goto fail; 10580a2d0d3fSVivek Goyal if (res == 0) 10590a2d0d3fSVivek Goyal goto invalid; 10600a2d0d3fSVivek Goyal 10610a2d0d3fSVivek Goyal if (buf[0] == '/') { 10620a2d0d3fSVivek Goyal for (s = buf; *s++ == '/'; s = next) { 10630a2d0d3fSVivek Goyal next = strchrnul(s, '/'); 10640a2d0d3fSVivek Goyal if (s == next) 10650a2d0d3fSVivek Goyal goto invalid; 10660a2d0d3fSVivek Goyal } 10670a2d0d3fSVivek Goyal } else { 10680a2d0d3fSVivek Goyal if (strchr(buf, '/') != NULL) 10690a2d0d3fSVivek Goyal goto invalid; 10700a2d0d3fSVivek Goyal } 10710a2d0d3fSVivek Goyal 10720a2d0d3fSVivek Goyal return buf; 10730a2d0d3fSVivek Goyal invalid: 10741bd0a3aeSlijiazi pr_warn_ratelimited("invalid redirect (%s)\n", buf); 10750a2d0d3fSVivek Goyal res = -EINVAL; 107692f0d6c9SMiklos Szeredi goto err_free; 107792f0d6c9SMiklos Szeredi fail: 107892f0d6c9SMiklos Szeredi pr_warn_ratelimited("failed to get redirect (%i)\n", res); 107992f0d6c9SMiklos Szeredi err_free: 1080993a0b2aSVivek Goyal kfree(buf); 1081993a0b2aSVivek Goyal return ERR_PTR(res); 10820a2d0d3fSVivek Goyal } 1083335d3fc5SSargun Dhillon 1084335d3fc5SSargun Dhillon /* 1085335d3fc5SSargun Dhillon * ovl_sync_status() - Check fs sync status for volatile mounts 1086335d3fc5SSargun Dhillon * 1087335d3fc5SSargun Dhillon * Returns 1 if this is not a volatile mount and a real sync is required. 1088335d3fc5SSargun Dhillon * 1089335d3fc5SSargun Dhillon * Returns 0 if syncing can be skipped because mount is volatile, and no errors 1090335d3fc5SSargun Dhillon * have occurred on the upperdir since the mount. 1091335d3fc5SSargun Dhillon * 1092335d3fc5SSargun Dhillon * Returns -errno if it is a volatile mount, and the error that occurred since 1093335d3fc5SSargun Dhillon * the last mount. If the error code changes, it'll return the latest error 1094335d3fc5SSargun Dhillon * code. 1095335d3fc5SSargun Dhillon */ 1096335d3fc5SSargun Dhillon 1097335d3fc5SSargun Dhillon int ovl_sync_status(struct ovl_fs *ofs) 1098335d3fc5SSargun Dhillon { 1099335d3fc5SSargun Dhillon struct vfsmount *mnt; 1100335d3fc5SSargun Dhillon 1101335d3fc5SSargun Dhillon if (ovl_should_sync(ofs)) 1102335d3fc5SSargun Dhillon return 1; 1103335d3fc5SSargun Dhillon 1104335d3fc5SSargun Dhillon mnt = ovl_upper_mnt(ofs); 1105335d3fc5SSargun Dhillon if (!mnt) 1106335d3fc5SSargun Dhillon return 0; 1107335d3fc5SSargun Dhillon 1108335d3fc5SSargun Dhillon return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq); 1109335d3fc5SSargun Dhillon } 11102878dffcSChristian Brauner 11112878dffcSChristian Brauner /* 11122878dffcSChristian Brauner * ovl_copyattr() - copy inode attributes from layer to ovl inode 11132878dffcSChristian Brauner * 11142878dffcSChristian Brauner * When overlay copies inode information from an upper or lower layer to the 11152878dffcSChristian Brauner * relevant overlay inode it will apply the idmapping of the upper or lower 11162878dffcSChristian Brauner * layer when doing so ensuring that the ovl inode ownership will correctly 11172878dffcSChristian Brauner * reflect the ownership of the idmapped upper or lower layer. For example, an 11182878dffcSChristian Brauner * idmapped upper or lower layer mapping id 1001 to id 1000 will take care to 11192878dffcSChristian Brauner * map any lower or upper inode owned by id 1001 to id 1000. These mapping 11202878dffcSChristian Brauner * helpers are nops when the relevant layer isn't idmapped. 11212878dffcSChristian Brauner */ 11222878dffcSChristian Brauner void ovl_copyattr(struct inode *inode) 11232878dffcSChristian Brauner { 11242878dffcSChristian Brauner struct path realpath; 11252878dffcSChristian Brauner struct inode *realinode; 1126e67fe633SChristian Brauner struct mnt_idmap *real_idmap; 112773db6a06SChristian Brauner vfsuid_t vfsuid; 112873db6a06SChristian Brauner vfsgid_t vfsgid; 11292878dffcSChristian Brauner 1130b2dd05f1SZhihao Cheng realinode = ovl_i_path_real(inode, &realpath); 1131e67fe633SChristian Brauner real_idmap = mnt_idmap(realpath.mnt); 11322878dffcSChristian Brauner 1133e67fe633SChristian Brauner vfsuid = i_uid_into_vfsuid(real_idmap, realinode); 1134e67fe633SChristian Brauner vfsgid = i_gid_into_vfsgid(real_idmap, realinode); 113573db6a06SChristian Brauner 113673db6a06SChristian Brauner inode->i_uid = vfsuid_into_kuid(vfsuid); 113773db6a06SChristian Brauner inode->i_gid = vfsgid_into_kgid(vfsgid); 11382878dffcSChristian Brauner inode->i_mode = realinode->i_mode; 11392878dffcSChristian Brauner inode->i_atime = realinode->i_atime; 11402878dffcSChristian Brauner inode->i_mtime = realinode->i_mtime; 11412878dffcSChristian Brauner inode->i_ctime = realinode->i_ctime; 11422878dffcSChristian Brauner i_size_write(inode, i_size_read(realinode)); 11432878dffcSChristian Brauner } 1144