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> 1302bcd157SAmir Goldstein #include <linux/uuid.h> 14caf70cb2SAmir Goldstein #include <linux/namei.h> 15caf70cb2SAmir Goldstein #include <linux/ratelimit.h> 16bbb1e54dSMiklos Szeredi #include "overlayfs.h" 17bbb1e54dSMiklos Szeredi 18bbb1e54dSMiklos Szeredi int ovl_want_write(struct dentry *dentry) 19bbb1e54dSMiklos Szeredi { 20bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 2108f4c7c8SMiklos Szeredi return mnt_want_write(ovl_upper_mnt(ofs)); 22bbb1e54dSMiklos Szeredi } 23bbb1e54dSMiklos Szeredi 24bbb1e54dSMiklos Szeredi void ovl_drop_write(struct dentry *dentry) 25bbb1e54dSMiklos Szeredi { 26bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 2708f4c7c8SMiklos Szeredi mnt_drop_write(ovl_upper_mnt(ofs)); 28bbb1e54dSMiklos Szeredi } 29bbb1e54dSMiklos Szeredi 30bbb1e54dSMiklos Szeredi struct dentry *ovl_workdir(struct dentry *dentry) 31bbb1e54dSMiklos Szeredi { 32bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 33bbb1e54dSMiklos Szeredi return ofs->workdir; 34bbb1e54dSMiklos Szeredi } 35bbb1e54dSMiklos Szeredi 36bbb1e54dSMiklos Szeredi const struct cred *ovl_override_creds(struct super_block *sb) 37bbb1e54dSMiklos Szeredi { 38bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = sb->s_fs_info; 39bbb1e54dSMiklos Szeredi 40bbb1e54dSMiklos Szeredi return override_creds(ofs->creator_cred); 41bbb1e54dSMiklos Szeredi } 42bbb1e54dSMiklos Szeredi 43e487d889SAmir Goldstein /* 44e487d889SAmir Goldstein * Check if underlying fs supports file handles and try to determine encoding 45e487d889SAmir Goldstein * type, in order to deduce maximum inode number used by fs. 46e487d889SAmir Goldstein * 47e487d889SAmir Goldstein * Return 0 if file handles are not supported. 48e487d889SAmir Goldstein * Return 1 (FILEID_INO32_GEN) if fs uses the default 32bit inode encoding. 49e487d889SAmir Goldstein * Return -1 if fs uses a non default encoding with unknown inode size. 50e487d889SAmir Goldstein */ 51e487d889SAmir Goldstein int ovl_can_decode_fh(struct super_block *sb) 5202bcd157SAmir Goldstein { 53c846af05SMiklos Szeredi if (!capable(CAP_DAC_READ_SEARCH)) 54c846af05SMiklos Szeredi return 0; 55c846af05SMiklos Szeredi 569df085f3SAmir Goldstein if (!sb->s_export_op || !sb->s_export_op->fh_to_dentry) 57e487d889SAmir Goldstein return 0; 58e487d889SAmir Goldstein 59e487d889SAmir Goldstein return sb->s_export_op->encode_fh ? -1 : FILEID_INO32_GEN; 6002bcd157SAmir Goldstein } 6102bcd157SAmir Goldstein 6202bcd157SAmir Goldstein struct dentry *ovl_indexdir(struct super_block *sb) 6302bcd157SAmir Goldstein { 6402bcd157SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 6502bcd157SAmir Goldstein 6602bcd157SAmir Goldstein return ofs->indexdir; 6702bcd157SAmir Goldstein } 6802bcd157SAmir Goldstein 69f168f109SAmir Goldstein /* Index all files on copy up. For now only enabled for NFS export */ 70f168f109SAmir Goldstein bool ovl_index_all(struct super_block *sb) 71f168f109SAmir Goldstein { 72f168f109SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 73f168f109SAmir Goldstein 74f168f109SAmir Goldstein return ofs->config.nfs_export && ofs->config.index; 75f168f109SAmir Goldstein } 76f168f109SAmir Goldstein 77f168f109SAmir Goldstein /* Verify lower origin on lookup. For now only enabled for NFS export */ 78f168f109SAmir Goldstein bool ovl_verify_lower(struct super_block *sb) 79f168f109SAmir Goldstein { 80f168f109SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 81f168f109SAmir Goldstein 82f168f109SAmir Goldstein return ofs->config.nfs_export && ofs->config.index; 83f168f109SAmir Goldstein } 84f168f109SAmir Goldstein 85bbb1e54dSMiklos Szeredi struct ovl_entry *ovl_alloc_entry(unsigned int numlower) 86bbb1e54dSMiklos Szeredi { 87bbb1e54dSMiklos Szeredi size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); 88bbb1e54dSMiklos Szeredi struct ovl_entry *oe = kzalloc(size, GFP_KERNEL); 89bbb1e54dSMiklos Szeredi 90bbb1e54dSMiklos Szeredi if (oe) 91bbb1e54dSMiklos Szeredi oe->numlower = numlower; 92bbb1e54dSMiklos Szeredi 93bbb1e54dSMiklos Szeredi return oe; 94bbb1e54dSMiklos Szeredi } 95bbb1e54dSMiklos Szeredi 96bbb1e54dSMiklos Szeredi bool ovl_dentry_remote(struct dentry *dentry) 97bbb1e54dSMiklos Szeredi { 98bbb1e54dSMiklos Szeredi return dentry->d_flags & 997925dad8SMiklos Szeredi (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); 100bbb1e54dSMiklos Szeredi } 101bbb1e54dSMiklos Szeredi 102f4288844SMiklos Szeredi void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, 103f4288844SMiklos Szeredi unsigned int mask) 104f4288844SMiklos Szeredi { 105f4288844SMiklos Szeredi struct ovl_entry *oe = OVL_E(dentry); 106f4288844SMiklos Szeredi unsigned int i, flags = 0; 107f4288844SMiklos Szeredi 108bccece1eSMiklos Szeredi if (upperdentry) 109bccece1eSMiklos Szeredi flags |= upperdentry->d_flags; 110f4288844SMiklos Szeredi for (i = 0; i < oe->numlower; i++) 111f4288844SMiklos Szeredi flags |= oe->lowerstack[i].dentry->d_flags; 112f4288844SMiklos Szeredi 113f4288844SMiklos Szeredi spin_lock(&dentry->d_lock); 114f4288844SMiklos Szeredi dentry->d_flags &= ~mask; 115f4288844SMiklos Szeredi dentry->d_flags |= flags & mask; 116f4288844SMiklos Szeredi spin_unlock(&dentry->d_lock); 117f4288844SMiklos Szeredi } 118f4288844SMiklos Szeredi 119bbb1e54dSMiklos Szeredi bool ovl_dentry_weird(struct dentry *dentry) 120bbb1e54dSMiklos Szeredi { 121bbb1e54dSMiklos Szeredi return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT | 122bbb1e54dSMiklos Szeredi DCACHE_MANAGE_TRANSIT | 123bbb1e54dSMiklos Szeredi DCACHE_OP_HASH | 124bbb1e54dSMiklos Szeredi DCACHE_OP_COMPARE); 125bbb1e54dSMiklos Szeredi } 126bbb1e54dSMiklos Szeredi 127bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_type(struct dentry *dentry) 128bbb1e54dSMiklos Szeredi { 129bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 130bbb1e54dSMiklos Szeredi enum ovl_path_type type = 0; 131bbb1e54dSMiklos Szeredi 13209d8b586SMiklos Szeredi if (ovl_dentry_upper(dentry)) { 133bbb1e54dSMiklos Szeredi type = __OVL_PATH_UPPER; 134bbb1e54dSMiklos Szeredi 135bbb1e54dSMiklos Szeredi /* 13659548503SAmir Goldstein * Non-dir dentry can hold lower dentry of its copy up origin. 137bbb1e54dSMiklos Szeredi */ 13859548503SAmir Goldstein if (oe->numlower) { 13960124877SVivek Goyal if (ovl_test_flag(OVL_CONST_INO, d_inode(dentry))) 14059548503SAmir Goldstein type |= __OVL_PATH_ORIGIN; 1410b17c28aSVivek Goyal if (d_is_dir(dentry) || 1420b17c28aSVivek Goyal !ovl_has_upperdata(d_inode(dentry))) 143bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 14459548503SAmir Goldstein } 145bbb1e54dSMiklos Szeredi } else { 146bbb1e54dSMiklos Szeredi if (oe->numlower > 1) 147bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 148bbb1e54dSMiklos Szeredi } 149bbb1e54dSMiklos Szeredi return type; 150bbb1e54dSMiklos Szeredi } 151bbb1e54dSMiklos Szeredi 152bbb1e54dSMiklos Szeredi void ovl_path_upper(struct dentry *dentry, struct path *path) 153bbb1e54dSMiklos Szeredi { 154bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 155bbb1e54dSMiklos Szeredi 15608f4c7c8SMiklos Szeredi path->mnt = ovl_upper_mnt(ofs); 15709d8b586SMiklos Szeredi path->dentry = ovl_dentry_upper(dentry); 158bbb1e54dSMiklos Szeredi } 159bbb1e54dSMiklos Szeredi 160bbb1e54dSMiklos Szeredi void ovl_path_lower(struct dentry *dentry, struct path *path) 161bbb1e54dSMiklos Szeredi { 162bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 163bbb1e54dSMiklos Szeredi 164b9343632SChandan Rajendra if (oe->numlower) { 165b9343632SChandan Rajendra path->mnt = oe->lowerstack[0].layer->mnt; 166b9343632SChandan Rajendra path->dentry = oe->lowerstack[0].dentry; 167b9343632SChandan Rajendra } else { 168b9343632SChandan Rajendra *path = (struct path) { }; 169b9343632SChandan Rajendra } 170bbb1e54dSMiklos Szeredi } 171bbb1e54dSMiklos Szeredi 1724f93b426SVivek Goyal void ovl_path_lowerdata(struct dentry *dentry, struct path *path) 1734f93b426SVivek Goyal { 1744f93b426SVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 1754f93b426SVivek Goyal 1764f93b426SVivek Goyal if (oe->numlower) { 1774f93b426SVivek Goyal path->mnt = oe->lowerstack[oe->numlower - 1].layer->mnt; 1784f93b426SVivek Goyal path->dentry = oe->lowerstack[oe->numlower - 1].dentry; 1794f93b426SVivek Goyal } else { 1804f93b426SVivek Goyal *path = (struct path) { }; 1814f93b426SVivek Goyal } 1824f93b426SVivek Goyal } 1834f93b426SVivek Goyal 184bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) 185bbb1e54dSMiklos Szeredi { 186bbb1e54dSMiklos Szeredi enum ovl_path_type type = ovl_path_type(dentry); 187bbb1e54dSMiklos Szeredi 188bbb1e54dSMiklos Szeredi if (!OVL_TYPE_UPPER(type)) 189bbb1e54dSMiklos Szeredi ovl_path_lower(dentry, path); 190bbb1e54dSMiklos Szeredi else 191bbb1e54dSMiklos Szeredi ovl_path_upper(dentry, path); 192bbb1e54dSMiklos Szeredi 193bbb1e54dSMiklos Szeredi return type; 194bbb1e54dSMiklos Szeredi } 195bbb1e54dSMiklos Szeredi 196bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_upper(struct dentry *dentry) 197bbb1e54dSMiklos Szeredi { 19809d8b586SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(d_inode(dentry))); 199bbb1e54dSMiklos Szeredi } 200bbb1e54dSMiklos Szeredi 201bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_lower(struct dentry *dentry) 202bbb1e54dSMiklos Szeredi { 203bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 204bbb1e54dSMiklos Szeredi 20509d8b586SMiklos Szeredi return oe->numlower ? oe->lowerstack[0].dentry : NULL; 206bbb1e54dSMiklos Szeredi } 207bbb1e54dSMiklos Szeredi 20813464165SMiklos Szeredi const struct ovl_layer *ovl_layer_lower(struct dentry *dentry) 209da309e8cSAmir Goldstein { 210da309e8cSAmir Goldstein struct ovl_entry *oe = dentry->d_fsdata; 211da309e8cSAmir Goldstein 212da309e8cSAmir Goldstein return oe->numlower ? oe->lowerstack[0].layer : NULL; 213da309e8cSAmir Goldstein } 214da309e8cSAmir Goldstein 215647d253fSVivek Goyal /* 216647d253fSVivek Goyal * ovl_dentry_lower() could return either a data dentry or metacopy dentry 217597534e7SXiong Zhenwu * depending on what is stored in lowerstack[0]. At times we need to find 218647d253fSVivek Goyal * lower dentry which has data (and not metacopy dentry). This helper 219647d253fSVivek Goyal * returns the lower data dentry. 220647d253fSVivek Goyal */ 221647d253fSVivek Goyal struct dentry *ovl_dentry_lowerdata(struct dentry *dentry) 222647d253fSVivek Goyal { 223647d253fSVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 224647d253fSVivek Goyal 225647d253fSVivek Goyal return oe->numlower ? oe->lowerstack[oe->numlower - 1].dentry : NULL; 226647d253fSVivek Goyal } 227647d253fSVivek Goyal 228bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_real(struct dentry *dentry) 229bbb1e54dSMiklos Szeredi { 23009d8b586SMiklos Szeredi return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry); 231bbb1e54dSMiklos Szeredi } 232bbb1e54dSMiklos Szeredi 2331d88f183SMiklos Szeredi struct dentry *ovl_i_dentry_upper(struct inode *inode) 2341d88f183SMiklos Szeredi { 2351d88f183SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(inode)); 2361d88f183SMiklos Szeredi } 2371d88f183SMiklos Szeredi 23809d8b586SMiklos Szeredi struct inode *ovl_inode_upper(struct inode *inode) 23925b7713aSMiklos Szeredi { 2401d88f183SMiklos Szeredi struct dentry *upperdentry = ovl_i_dentry_upper(inode); 24125b7713aSMiklos Szeredi 24209d8b586SMiklos Szeredi return upperdentry ? d_inode(upperdentry) : NULL; 24325b7713aSMiklos Szeredi } 24425b7713aSMiklos Szeredi 24509d8b586SMiklos Szeredi struct inode *ovl_inode_lower(struct inode *inode) 24609d8b586SMiklos Szeredi { 24709d8b586SMiklos Szeredi return OVL_I(inode)->lower; 24809d8b586SMiklos Szeredi } 24909d8b586SMiklos Szeredi 25009d8b586SMiklos Szeredi struct inode *ovl_inode_real(struct inode *inode) 25109d8b586SMiklos Szeredi { 25209d8b586SMiklos Szeredi return ovl_inode_upper(inode) ?: ovl_inode_lower(inode); 25309d8b586SMiklos Szeredi } 25409d8b586SMiklos Szeredi 2552664bd08SVivek Goyal /* Return inode which contains lower data. Do not return metacopy */ 2562664bd08SVivek Goyal struct inode *ovl_inode_lowerdata(struct inode *inode) 2572664bd08SVivek Goyal { 2582664bd08SVivek Goyal if (WARN_ON(!S_ISREG(inode->i_mode))) 2592664bd08SVivek Goyal return NULL; 2602664bd08SVivek Goyal 2612664bd08SVivek Goyal return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode); 2622664bd08SVivek Goyal } 26309d8b586SMiklos Szeredi 2644823d49cSVivek Goyal /* Return real inode which contains data. Does not return metacopy inode */ 2654823d49cSVivek Goyal struct inode *ovl_inode_realdata(struct inode *inode) 2664823d49cSVivek Goyal { 2674823d49cSVivek Goyal struct inode *upperinode; 2684823d49cSVivek Goyal 2694823d49cSVivek Goyal upperinode = ovl_inode_upper(inode); 2704823d49cSVivek Goyal if (upperinode && ovl_has_upperdata(inode)) 2714823d49cSVivek Goyal return upperinode; 2724823d49cSVivek Goyal 2734823d49cSVivek Goyal return ovl_inode_lowerdata(inode); 2744823d49cSVivek Goyal } 2754823d49cSVivek Goyal 2764edb83bbSMiklos Szeredi struct ovl_dir_cache *ovl_dir_cache(struct inode *inode) 277bbb1e54dSMiklos Szeredi { 2784edb83bbSMiklos Szeredi return OVL_I(inode)->cache; 279bbb1e54dSMiklos Szeredi } 280bbb1e54dSMiklos Szeredi 2814edb83bbSMiklos Szeredi void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache) 282bbb1e54dSMiklos Szeredi { 2834edb83bbSMiklos Szeredi OVL_I(inode)->cache = cache; 284bbb1e54dSMiklos Szeredi } 285bbb1e54dSMiklos Szeredi 286c62520a8SAmir Goldstein void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry) 287c62520a8SAmir Goldstein { 288c62520a8SAmir Goldstein set_bit(flag, &OVL_E(dentry)->flags); 289c62520a8SAmir Goldstein } 290c62520a8SAmir Goldstein 291c62520a8SAmir Goldstein void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry) 292c62520a8SAmir Goldstein { 293c62520a8SAmir Goldstein clear_bit(flag, &OVL_E(dentry)->flags); 294c62520a8SAmir Goldstein } 295c62520a8SAmir Goldstein 296c62520a8SAmir Goldstein bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry) 297c62520a8SAmir Goldstein { 298c62520a8SAmir Goldstein return test_bit(flag, &OVL_E(dentry)->flags); 299c62520a8SAmir Goldstein } 300c62520a8SAmir Goldstein 301bbb1e54dSMiklos Szeredi bool ovl_dentry_is_opaque(struct dentry *dentry) 302bbb1e54dSMiklos Szeredi { 303c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_OPAQUE, dentry); 304bbb1e54dSMiklos Szeredi } 305bbb1e54dSMiklos Szeredi 306bbb1e54dSMiklos Szeredi bool ovl_dentry_is_whiteout(struct dentry *dentry) 307bbb1e54dSMiklos Szeredi { 308bbb1e54dSMiklos Szeredi return !dentry->d_inode && ovl_dentry_is_opaque(dentry); 309bbb1e54dSMiklos Szeredi } 310bbb1e54dSMiklos Szeredi 3115cf5b477SMiklos Szeredi void ovl_dentry_set_opaque(struct dentry *dentry) 312bbb1e54dSMiklos Szeredi { 313c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_OPAQUE, dentry); 314bbb1e54dSMiklos Szeredi } 315bbb1e54dSMiklos Szeredi 31655acc661SMiklos Szeredi /* 317aa3ff3c1SAmir Goldstein * For hard links and decoded file handles, it's possible for ovl_dentry_upper() 318aa3ff3c1SAmir Goldstein * to return positive, while there's no actual upper alias for the inode. 319aa3ff3c1SAmir Goldstein * Copy up code needs to know about the existence of the upper alias, so it 320aa3ff3c1SAmir Goldstein * can't use ovl_dentry_upper(). 32155acc661SMiklos Szeredi */ 32255acc661SMiklos Szeredi bool ovl_dentry_has_upper_alias(struct dentry *dentry) 32355acc661SMiklos Szeredi { 324c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_UPPER_ALIAS, dentry); 32555acc661SMiklos Szeredi } 32655acc661SMiklos Szeredi 32755acc661SMiklos Szeredi void ovl_dentry_set_upper_alias(struct dentry *dentry) 32855acc661SMiklos Szeredi { 329c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_UPPER_ALIAS, dentry); 33055acc661SMiklos Szeredi } 33155acc661SMiklos Szeredi 3320c288874SVivek Goyal static bool ovl_should_check_upperdata(struct inode *inode) 3330c288874SVivek Goyal { 3340c288874SVivek Goyal if (!S_ISREG(inode->i_mode)) 3350c288874SVivek Goyal return false; 3360c288874SVivek Goyal 3370c288874SVivek Goyal if (!ovl_inode_lower(inode)) 3380c288874SVivek Goyal return false; 3390c288874SVivek Goyal 3400c288874SVivek Goyal return true; 3410c288874SVivek Goyal } 3420c288874SVivek Goyal 3430c288874SVivek Goyal bool ovl_has_upperdata(struct inode *inode) 3440c288874SVivek Goyal { 3450c288874SVivek Goyal if (!ovl_should_check_upperdata(inode)) 3460c288874SVivek Goyal return true; 3470c288874SVivek Goyal 3480c288874SVivek Goyal if (!ovl_test_flag(OVL_UPPERDATA, inode)) 3490c288874SVivek Goyal return false; 3500c288874SVivek Goyal /* 3510c288874SVivek Goyal * Pairs with smp_wmb() in ovl_set_upperdata(). Main user of 3520c288874SVivek Goyal * ovl_has_upperdata() is ovl_copy_up_meta_inode_data(). Make sure 3530c288874SVivek Goyal * if setting of OVL_UPPERDATA is visible, then effects of writes 3540c288874SVivek Goyal * before that are visible too. 3550c288874SVivek Goyal */ 3560c288874SVivek Goyal smp_rmb(); 3570c288874SVivek Goyal return true; 3580c288874SVivek Goyal } 3590c288874SVivek Goyal 3600c288874SVivek Goyal void ovl_set_upperdata(struct inode *inode) 3610c288874SVivek Goyal { 3620c288874SVivek Goyal /* 3630c288874SVivek Goyal * Pairs with smp_rmb() in ovl_has_upperdata(). Make sure 3640c288874SVivek Goyal * if OVL_UPPERDATA flag is visible, then effects of write operations 3650c288874SVivek Goyal * before it are visible as well. 3660c288874SVivek Goyal */ 3670c288874SVivek Goyal smp_wmb(); 3680c288874SVivek Goyal ovl_set_flag(OVL_UPPERDATA, inode); 3690c288874SVivek Goyal } 3700c288874SVivek Goyal 3710c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 3720c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags) 3730c288874SVivek Goyal { 3740c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 3750c288874SVivek Goyal return false; 3760c288874SVivek Goyal 3770c288874SVivek Goyal return !ovl_test_flag(OVL_UPPERDATA, d_inode(dentry)); 3780c288874SVivek Goyal } 3790c288874SVivek Goyal 3800c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags) 3810c288874SVivek Goyal { 3820c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 3830c288874SVivek Goyal return false; 3840c288874SVivek Goyal 3850c288874SVivek Goyal return !ovl_has_upperdata(d_inode(dentry)); 3860c288874SVivek Goyal } 3870c288874SVivek Goyal 388a6c60655SMiklos Szeredi bool ovl_redirect_dir(struct super_block *sb) 389a6c60655SMiklos Szeredi { 390a6c60655SMiklos Szeredi struct ovl_fs *ofs = sb->s_fs_info; 391a6c60655SMiklos Szeredi 39221a22878SAmir Goldstein return ofs->config.redirect_dir && !ofs->noxattr; 393a6c60655SMiklos Szeredi } 394a6c60655SMiklos Szeredi 395a6c60655SMiklos Szeredi const char *ovl_dentry_get_redirect(struct dentry *dentry) 396a6c60655SMiklos Szeredi { 397cf31c463SMiklos Szeredi return OVL_I(d_inode(dentry))->redirect; 398a6c60655SMiklos Szeredi } 399a6c60655SMiklos Szeredi 400a6c60655SMiklos Szeredi void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect) 401a6c60655SMiklos Szeredi { 402cf31c463SMiklos Szeredi struct ovl_inode *oi = OVL_I(d_inode(dentry)); 403a6c60655SMiklos Szeredi 404cf31c463SMiklos Szeredi kfree(oi->redirect); 405cf31c463SMiklos Szeredi oi->redirect = redirect; 406a6c60655SMiklos Szeredi } 407a6c60655SMiklos Szeredi 40809d8b586SMiklos Szeredi void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) 409bbb1e54dSMiklos Szeredi { 41009d8b586SMiklos Szeredi struct inode *upperinode = d_inode(upperdentry); 411e6d2ebddSMiklos Szeredi 41209d8b586SMiklos Szeredi WARN_ON(OVL_I(inode)->__upperdentry); 41309d8b586SMiklos Szeredi 41425b7713aSMiklos Szeredi /* 41509d8b586SMiklos Szeredi * Make sure upperdentry is consistent before making it visible 41625b7713aSMiklos Szeredi */ 41725b7713aSMiklos Szeredi smp_wmb(); 41809d8b586SMiklos Szeredi OVL_I(inode)->__upperdentry = upperdentry; 41931747edaSAmir Goldstein if (inode_unhashed(inode)) { 42025b7713aSMiklos Szeredi inode->i_private = upperinode; 421bbb1e54dSMiklos Szeredi __insert_inode_hash(inode, (unsigned long) upperinode); 422bbb1e54dSMiklos Szeredi } 42325b7713aSMiklos Szeredi } 424bbb1e54dSMiklos Szeredi 425*65cd913eSAmir Goldstein static void ovl_dir_version_inc(struct dentry *dentry, bool impurity) 426bbb1e54dSMiklos Szeredi { 42704a01ac7SMiklos Szeredi struct inode *inode = d_inode(dentry); 428bbb1e54dSMiklos Szeredi 42904a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 430*65cd913eSAmir Goldstein WARN_ON(!d_is_dir(dentry)); 4314edb83bbSMiklos Szeredi /* 432*65cd913eSAmir Goldstein * Version is used by readdir code to keep cache consistent. 433*65cd913eSAmir Goldstein * For merge dirs (or dirs with origin) all changes need to be noted. 434*65cd913eSAmir Goldstein * For non-merge dirs, cache contains only impure entries (i.e. ones 435*65cd913eSAmir Goldstein * which have been copied up and have origins), so only need to note 436*65cd913eSAmir Goldstein * changes to impure entries. 4374edb83bbSMiklos Szeredi */ 438*65cd913eSAmir Goldstein if (!ovl_dir_is_real(dentry) || impurity) 43904a01ac7SMiklos Szeredi OVL_I(inode)->version++; 440bbb1e54dSMiklos Szeredi } 441bbb1e54dSMiklos Szeredi 442d9854c87SMiklos Szeredi void ovl_dir_modified(struct dentry *dentry, bool impurity) 443d9854c87SMiklos Szeredi { 444d9854c87SMiklos Szeredi /* Copy mtime/ctime */ 445d9854c87SMiklos Szeredi ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry)); 446d9854c87SMiklos Szeredi 447*65cd913eSAmir Goldstein ovl_dir_version_inc(dentry, impurity); 448d9854c87SMiklos Szeredi } 449d9854c87SMiklos Szeredi 450bbb1e54dSMiklos Szeredi u64 ovl_dentry_version_get(struct dentry *dentry) 451bbb1e54dSMiklos Szeredi { 45204a01ac7SMiklos Szeredi struct inode *inode = d_inode(dentry); 453bbb1e54dSMiklos Szeredi 45404a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 45504a01ac7SMiklos Szeredi return OVL_I(inode)->version; 456bbb1e54dSMiklos Szeredi } 457bbb1e54dSMiklos Szeredi 458bbb1e54dSMiklos Szeredi bool ovl_is_whiteout(struct dentry *dentry) 459bbb1e54dSMiklos Szeredi { 460bbb1e54dSMiklos Szeredi struct inode *inode = dentry->d_inode; 461bbb1e54dSMiklos Szeredi 462bbb1e54dSMiklos Szeredi return inode && IS_WHITEOUT(inode); 463bbb1e54dSMiklos Szeredi } 464bbb1e54dSMiklos Szeredi 465bbb1e54dSMiklos Szeredi struct file *ovl_path_open(struct path *path, int flags) 466bbb1e54dSMiklos Szeredi { 46756230d95SMiklos Szeredi struct inode *inode = d_inode(path->dentry); 46856230d95SMiklos Szeredi int err, acc_mode; 46956230d95SMiklos Szeredi 47056230d95SMiklos Szeredi if (flags & ~(O_ACCMODE | O_LARGEFILE)) 47156230d95SMiklos Szeredi BUG(); 47256230d95SMiklos Szeredi 47356230d95SMiklos Szeredi switch (flags & O_ACCMODE) { 47456230d95SMiklos Szeredi case O_RDONLY: 47556230d95SMiklos Szeredi acc_mode = MAY_READ; 47656230d95SMiklos Szeredi break; 47756230d95SMiklos Szeredi case O_WRONLY: 47856230d95SMiklos Szeredi acc_mode = MAY_WRITE; 47956230d95SMiklos Szeredi break; 48056230d95SMiklos Szeredi default: 48156230d95SMiklos Szeredi BUG(); 48256230d95SMiklos Szeredi } 48356230d95SMiklos Szeredi 48447291baaSChristian Brauner err = inode_permission(&init_user_ns, inode, acc_mode | MAY_OPEN); 48556230d95SMiklos Szeredi if (err) 48656230d95SMiklos Szeredi return ERR_PTR(err); 48756230d95SMiklos Szeredi 48856230d95SMiklos Szeredi /* O_NOATIME is an optimization, don't fail if not permitted */ 48921cb47beSChristian Brauner if (inode_owner_or_capable(&init_user_ns, inode)) 49056230d95SMiklos Szeredi flags |= O_NOATIME; 49156230d95SMiklos Szeredi 49256230d95SMiklos Szeredi return dentry_open(path, flags, current_cred()); 493bbb1e54dSMiklos Szeredi } 49439d3d60aSAmir Goldstein 4950c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 4960c288874SVivek Goyal static bool ovl_already_copied_up_locked(struct dentry *dentry, int flags) 4970c288874SVivek Goyal { 4980c288874SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 4990c288874SVivek Goyal 5000c288874SVivek Goyal if (ovl_dentry_upper(dentry) && 5010c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 5020c288874SVivek Goyal !ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 5030c288874SVivek Goyal return true; 5040c288874SVivek Goyal 5050c288874SVivek Goyal return false; 5060c288874SVivek Goyal } 5070c288874SVivek Goyal 5080c288874SVivek Goyal bool ovl_already_copied_up(struct dentry *dentry, int flags) 5092002df85SVivek Goyal { 5102002df85SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 5112002df85SVivek Goyal 5122002df85SVivek Goyal /* 5132002df85SVivek Goyal * Check if copy-up has happened as well as for upper alias (in 5142002df85SVivek Goyal * case of hard links) is there. 5152002df85SVivek Goyal * 5162002df85SVivek Goyal * Both checks are lockless: 5172002df85SVivek Goyal * - false negatives: will recheck under oi->lock 5182002df85SVivek Goyal * - false positives: 5192002df85SVivek Goyal * + ovl_dentry_upper() uses memory barriers to ensure the 5202002df85SVivek Goyal * upper dentry is up-to-date 5212002df85SVivek Goyal * + ovl_dentry_has_upper_alias() relies on locking of 5222002df85SVivek Goyal * upper parent i_rwsem to prevent reordering copy-up 5232002df85SVivek Goyal * with rename. 5242002df85SVivek Goyal */ 5252002df85SVivek Goyal if (ovl_dentry_upper(dentry) && 5260c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 5270c288874SVivek Goyal !ovl_dentry_needs_data_copy_up(dentry, flags)) 5282002df85SVivek Goyal return true; 5292002df85SVivek Goyal 5302002df85SVivek Goyal return false; 5312002df85SVivek Goyal } 5322002df85SVivek Goyal 5330c288874SVivek Goyal int ovl_copy_up_start(struct dentry *dentry, int flags) 53439d3d60aSAmir Goldstein { 5351e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 53639d3d60aSAmir Goldstein int err; 53739d3d60aSAmir Goldstein 538531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 5390c288874SVivek Goyal if (!err && ovl_already_copied_up_locked(dentry, flags)) { 54039d3d60aSAmir Goldstein err = 1; /* Already copied up */ 5411e92e307SAmir Goldstein ovl_inode_unlock(inode); 54239d3d60aSAmir Goldstein } 54339d3d60aSAmir Goldstein 54439d3d60aSAmir Goldstein return err; 54539d3d60aSAmir Goldstein } 54639d3d60aSAmir Goldstein 54739d3d60aSAmir Goldstein void ovl_copy_up_end(struct dentry *dentry) 54839d3d60aSAmir Goldstein { 5491e92e307SAmir Goldstein ovl_inode_unlock(d_inode(dentry)); 55039d3d60aSAmir Goldstein } 55182b749b2SAmir Goldstein 552610afc0bSMiklos Szeredi bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry) 553b79e05aaSAmir Goldstein { 554b79e05aaSAmir Goldstein int res; 555b79e05aaSAmir Goldstein 556610afc0bSMiklos Szeredi res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_ORIGIN, NULL, 0); 557b79e05aaSAmir Goldstein 558b79e05aaSAmir Goldstein /* Zero size value means "copied up but origin unknown" */ 559b79e05aaSAmir Goldstein if (res >= 0) 560b79e05aaSAmir Goldstein return true; 561b79e05aaSAmir Goldstein 562b79e05aaSAmir Goldstein return false; 563b79e05aaSAmir Goldstein } 564b79e05aaSAmir Goldstein 565610afc0bSMiklos Szeredi bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry, 56643d193f8SMiklos Szeredi enum ovl_xattr ox) 567f3a15685SAmir Goldstein { 568f3a15685SAmir Goldstein int res; 569f3a15685SAmir Goldstein char val; 570f3a15685SAmir Goldstein 571f3a15685SAmir Goldstein if (!d_is_dir(dentry)) 572f3a15685SAmir Goldstein return false; 573f3a15685SAmir Goldstein 57443d193f8SMiklos Szeredi res = ovl_do_getxattr(OVL_FS(sb), dentry, ox, &val, 1); 575f3a15685SAmir Goldstein if (res == 1 && val == 'y') 576f3a15685SAmir Goldstein return true; 577f3a15685SAmir Goldstein 578f3a15685SAmir Goldstein return false; 579f3a15685SAmir Goldstein } 580f3a15685SAmir Goldstein 58143d193f8SMiklos Szeredi #define OVL_XATTR_OPAQUE_POSTFIX "opaque" 58243d193f8SMiklos Szeredi #define OVL_XATTR_REDIRECT_POSTFIX "redirect" 58343d193f8SMiklos Szeredi #define OVL_XATTR_ORIGIN_POSTFIX "origin" 58443d193f8SMiklos Szeredi #define OVL_XATTR_IMPURE_POSTFIX "impure" 58543d193f8SMiklos Szeredi #define OVL_XATTR_NLINK_POSTFIX "nlink" 58643d193f8SMiklos Szeredi #define OVL_XATTR_UPPER_POSTFIX "upper" 58743d193f8SMiklos Szeredi #define OVL_XATTR_METACOPY_POSTFIX "metacopy" 58843d193f8SMiklos Szeredi 58943d193f8SMiklos Szeredi #define OVL_XATTR_TAB_ENTRY(x) \ 5902d2f2d73SMiklos Szeredi [x] = { [false] = OVL_XATTR_TRUSTED_PREFIX x ## _POSTFIX, \ 5912d2f2d73SMiklos Szeredi [true] = OVL_XATTR_USER_PREFIX x ## _POSTFIX } 59243d193f8SMiklos Szeredi 5932d2f2d73SMiklos Szeredi const char *const ovl_xattr_table[][2] = { 59443d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_OPAQUE), 59543d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_REDIRECT), 59643d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_ORIGIN), 59743d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_IMPURE), 59843d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_NLINK), 59943d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_UPPER), 60043d193f8SMiklos Szeredi OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY), 60143d193f8SMiklos Szeredi }; 60243d193f8SMiklos Szeredi 60382b749b2SAmir Goldstein int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, 60443d193f8SMiklos Szeredi enum ovl_xattr ox, const void *value, size_t size, 60582b749b2SAmir Goldstein int xerr) 60682b749b2SAmir Goldstein { 60782b749b2SAmir Goldstein int err; 60882b749b2SAmir Goldstein struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 60982b749b2SAmir Goldstein 61082b749b2SAmir Goldstein if (ofs->noxattr) 61182b749b2SAmir Goldstein return xerr; 61282b749b2SAmir Goldstein 61343d193f8SMiklos Szeredi err = ovl_do_setxattr(ofs, upperdentry, ox, value, size); 61482b749b2SAmir Goldstein 61582b749b2SAmir Goldstein if (err == -EOPNOTSUPP) { 61643d193f8SMiklos Szeredi pr_warn("cannot set %s xattr on upper\n", ovl_xattr(ofs, ox)); 61782b749b2SAmir Goldstein ofs->noxattr = true; 61882b749b2SAmir Goldstein return xerr; 61982b749b2SAmir Goldstein } 62082b749b2SAmir Goldstein 62182b749b2SAmir Goldstein return err; 62282b749b2SAmir Goldstein } 623f3a15685SAmir Goldstein 624f3a15685SAmir Goldstein int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry) 625f3a15685SAmir Goldstein { 626f3a15685SAmir Goldstein int err; 627f3a15685SAmir Goldstein 62813c72075SMiklos Szeredi if (ovl_test_flag(OVL_IMPURE, d_inode(dentry))) 629f3a15685SAmir Goldstein return 0; 630f3a15685SAmir Goldstein 631f3a15685SAmir Goldstein /* 632f3a15685SAmir Goldstein * Do not fail when upper doesn't support xattrs. 633f3a15685SAmir Goldstein * Upper inodes won't have origin nor redirect xattr anyway. 634f3a15685SAmir Goldstein */ 635f3a15685SAmir Goldstein err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE, 636f3a15685SAmir Goldstein "y", 1, 0); 637f3a15685SAmir Goldstein if (!err) 63813c72075SMiklos Szeredi ovl_set_flag(OVL_IMPURE, d_inode(dentry)); 639f3a15685SAmir Goldstein 640f3a15685SAmir Goldstein return err; 641f3a15685SAmir Goldstein } 64213c72075SMiklos Szeredi 643ad0af710SAmir Goldstein /** 644ad0af710SAmir Goldstein * Caller must hold a reference to inode to prevent it from being freed while 645ad0af710SAmir Goldstein * it is marked inuse. 646ad0af710SAmir Goldstein */ 647ad0af710SAmir Goldstein bool ovl_inuse_trylock(struct dentry *dentry) 648ad0af710SAmir Goldstein { 649ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 650ad0af710SAmir Goldstein bool locked = false; 651ad0af710SAmir Goldstein 652ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 653ad0af710SAmir Goldstein if (!(inode->i_state & I_OVL_INUSE)) { 654ad0af710SAmir Goldstein inode->i_state |= I_OVL_INUSE; 655ad0af710SAmir Goldstein locked = true; 656ad0af710SAmir Goldstein } 657ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 658ad0af710SAmir Goldstein 659ad0af710SAmir Goldstein return locked; 660ad0af710SAmir Goldstein } 661ad0af710SAmir Goldstein 662ad0af710SAmir Goldstein void ovl_inuse_unlock(struct dentry *dentry) 663ad0af710SAmir Goldstein { 664ad0af710SAmir Goldstein if (dentry) { 665ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 666ad0af710SAmir Goldstein 667ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 668ad0af710SAmir Goldstein WARN_ON(!(inode->i_state & I_OVL_INUSE)); 669ad0af710SAmir Goldstein inode->i_state &= ~I_OVL_INUSE; 670ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 671ad0af710SAmir Goldstein } 672ad0af710SAmir Goldstein } 6735f8415d6SAmir Goldstein 674146d62e5SAmir Goldstein bool ovl_is_inuse(struct dentry *dentry) 675146d62e5SAmir Goldstein { 676146d62e5SAmir Goldstein struct inode *inode = d_inode(dentry); 677146d62e5SAmir Goldstein bool inuse; 678146d62e5SAmir Goldstein 679146d62e5SAmir Goldstein spin_lock(&inode->i_lock); 680146d62e5SAmir Goldstein inuse = (inode->i_state & I_OVL_INUSE); 681146d62e5SAmir Goldstein spin_unlock(&inode->i_lock); 682146d62e5SAmir Goldstein 683146d62e5SAmir Goldstein return inuse; 684146d62e5SAmir Goldstein } 685146d62e5SAmir Goldstein 68624b33ee1SAmir Goldstein /* 68724b33ee1SAmir Goldstein * Does this overlay dentry need to be indexed on copy up? 68824b33ee1SAmir Goldstein */ 68924b33ee1SAmir Goldstein bool ovl_need_index(struct dentry *dentry) 69024b33ee1SAmir Goldstein { 69124b33ee1SAmir Goldstein struct dentry *lower = ovl_dentry_lower(dentry); 69224b33ee1SAmir Goldstein 69324b33ee1SAmir Goldstein if (!lower || !ovl_indexdir(dentry->d_sb)) 69424b33ee1SAmir Goldstein return false; 69524b33ee1SAmir Goldstein 696fbd2d207SAmir Goldstein /* Index all files for NFS export and consistency verification */ 697016b720fSAmir Goldstein if (ovl_index_all(dentry->d_sb)) 698fbd2d207SAmir Goldstein return true; 699fbd2d207SAmir Goldstein 70024b33ee1SAmir Goldstein /* Index only lower hardlinks on copy up */ 70124b33ee1SAmir Goldstein if (!d_is_dir(lower) && d_inode(lower)->i_nlink > 1) 70224b33ee1SAmir Goldstein return true; 70324b33ee1SAmir Goldstein 70424b33ee1SAmir Goldstein return false; 70524b33ee1SAmir Goldstein } 70624b33ee1SAmir Goldstein 7079f4ec904SAmir Goldstein /* Caller must hold OVL_I(inode)->lock */ 708caf70cb2SAmir Goldstein static void ovl_cleanup_index(struct dentry *dentry) 709caf70cb2SAmir Goldstein { 7101cdb0cb6SPavel Tikhomirov struct ovl_fs *ofs = OVL_FS(dentry->d_sb); 711e7dd0e71SAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 712e7dd0e71SAmir Goldstein struct inode *dir = indexdir->d_inode; 713caf70cb2SAmir Goldstein struct dentry *lowerdentry = ovl_dentry_lower(dentry); 714caf70cb2SAmir Goldstein struct dentry *upperdentry = ovl_dentry_upper(dentry); 715caf70cb2SAmir Goldstein struct dentry *index = NULL; 716caf70cb2SAmir Goldstein struct inode *inode; 71763e13252SAmir Goldstein struct qstr name = { }; 718caf70cb2SAmir Goldstein int err; 719caf70cb2SAmir Goldstein 7201cdb0cb6SPavel Tikhomirov err = ovl_get_index_name(ofs, lowerdentry, &name); 721caf70cb2SAmir Goldstein if (err) 722caf70cb2SAmir Goldstein goto fail; 723caf70cb2SAmir Goldstein 724caf70cb2SAmir Goldstein inode = d_inode(upperdentry); 72589a17556SAmir Goldstein if (!S_ISDIR(inode->i_mode) && inode->i_nlink != 1) { 7261bd0a3aeSlijiazi pr_warn_ratelimited("cleanup linked index (%pd2, ino=%lu, nlink=%u)\n", 727caf70cb2SAmir Goldstein upperdentry, inode->i_ino, inode->i_nlink); 728caf70cb2SAmir Goldstein /* 729caf70cb2SAmir Goldstein * We either have a bug with persistent union nlink or a lower 730caf70cb2SAmir Goldstein * hardlink was added while overlay is mounted. Adding a lower 731caf70cb2SAmir Goldstein * hardlink and then unlinking all overlay hardlinks would drop 732caf70cb2SAmir Goldstein * overlay nlink to zero before all upper inodes are unlinked. 733caf70cb2SAmir Goldstein * As a safety measure, when that situation is detected, set 734caf70cb2SAmir Goldstein * the overlay nlink to the index inode nlink minus one for the 735caf70cb2SAmir Goldstein * index entry itself. 736caf70cb2SAmir Goldstein */ 737caf70cb2SAmir Goldstein set_nlink(d_inode(dentry), inode->i_nlink - 1); 738caf70cb2SAmir Goldstein ovl_set_nlink_upper(dentry); 739caf70cb2SAmir Goldstein goto out; 740caf70cb2SAmir Goldstein } 741caf70cb2SAmir Goldstein 742caf70cb2SAmir Goldstein inode_lock_nested(dir, I_MUTEX_PARENT); 743e7dd0e71SAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 744caf70cb2SAmir Goldstein err = PTR_ERR(index); 745e7dd0e71SAmir Goldstein if (IS_ERR(index)) { 7469f4ec904SAmir Goldstein index = NULL; 747e7dd0e71SAmir Goldstein } else if (ovl_index_all(dentry->d_sb)) { 748e7dd0e71SAmir Goldstein /* Whiteout orphan index to block future open by handle */ 749c21c839bSChengguang Xu err = ovl_cleanup_and_whiteout(OVL_FS(dentry->d_sb), 750c21c839bSChengguang Xu dir, index); 751e7dd0e71SAmir Goldstein } else { 752e7dd0e71SAmir Goldstein /* Cleanup orphan index entries */ 753e7dd0e71SAmir Goldstein err = ovl_cleanup(dir, index); 754e7dd0e71SAmir Goldstein } 7559f4ec904SAmir Goldstein 756caf70cb2SAmir Goldstein inode_unlock(dir); 757caf70cb2SAmir Goldstein if (err) 758caf70cb2SAmir Goldstein goto fail; 759caf70cb2SAmir Goldstein 760caf70cb2SAmir Goldstein out: 76163e13252SAmir Goldstein kfree(name.name); 762caf70cb2SAmir Goldstein dput(index); 763caf70cb2SAmir Goldstein return; 764caf70cb2SAmir Goldstein 765caf70cb2SAmir Goldstein fail: 7661bd0a3aeSlijiazi pr_err("cleanup index of '%pd2' failed (%i)\n", dentry, err); 767caf70cb2SAmir Goldstein goto out; 768caf70cb2SAmir Goldstein } 769caf70cb2SAmir Goldstein 7705f8415d6SAmir Goldstein /* 7715f8415d6SAmir Goldstein * Operations that change overlay inode and upper inode nlink need to be 7725f8415d6SAmir Goldstein * synchronized with copy up for persistent nlink accounting. 7735f8415d6SAmir Goldstein */ 7740e32992fSAmir Goldstein int ovl_nlink_start(struct dentry *dentry) 7755f8415d6SAmir Goldstein { 7761e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 7775f8415d6SAmir Goldstein const struct cred *old_cred; 7785f8415d6SAmir Goldstein int err; 7795f8415d6SAmir Goldstein 7801e92e307SAmir Goldstein if (WARN_ON(!inode)) 7810e32992fSAmir Goldstein return -ENOENT; 7825f8415d6SAmir Goldstein 7835f8415d6SAmir Goldstein /* 7845f8415d6SAmir Goldstein * With inodes index is enabled, we store the union overlay nlink 78524b33ee1SAmir Goldstein * in an xattr on the index inode. When whiting out an indexed lower, 7865f8415d6SAmir Goldstein * we need to decrement the overlay persistent nlink, but before the 7875f8415d6SAmir Goldstein * first copy up, we have no upper index inode to store the xattr. 7885f8415d6SAmir Goldstein * 78924b33ee1SAmir Goldstein * As a workaround, before whiteout/rename over an indexed lower, 7905f8415d6SAmir Goldstein * copy up to create the upper index. Creating the upper index will 7915f8415d6SAmir Goldstein * initialize the overlay nlink, so it could be dropped if unlink 7925f8415d6SAmir Goldstein * or rename succeeds. 7935f8415d6SAmir Goldstein * 7945f8415d6SAmir Goldstein * TODO: implement metadata only index copy up when called with 7955f8415d6SAmir Goldstein * ovl_copy_up_flags(dentry, O_PATH). 7965f8415d6SAmir Goldstein */ 79724b33ee1SAmir Goldstein if (ovl_need_index(dentry) && !ovl_dentry_has_upper_alias(dentry)) { 7985f8415d6SAmir Goldstein err = ovl_copy_up(dentry); 7995f8415d6SAmir Goldstein if (err) 8005f8415d6SAmir Goldstein return err; 8015f8415d6SAmir Goldstein } 8025f8415d6SAmir Goldstein 803531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 8045f8415d6SAmir Goldstein if (err) 8055f8415d6SAmir Goldstein return err; 8065f8415d6SAmir Goldstein 8071e92e307SAmir Goldstein if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, inode)) 8085f8415d6SAmir Goldstein goto out; 8095f8415d6SAmir Goldstein 8105f8415d6SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 8115f8415d6SAmir Goldstein /* 8125f8415d6SAmir Goldstein * The overlay inode nlink should be incremented/decremented IFF the 8135f8415d6SAmir Goldstein * upper operation succeeds, along with nlink change of upper inode. 8145f8415d6SAmir Goldstein * Therefore, before link/unlink/rename, we store the union nlink 8155f8415d6SAmir Goldstein * value relative to the upper inode nlink in an upper inode xattr. 8165f8415d6SAmir Goldstein */ 8175f8415d6SAmir Goldstein err = ovl_set_nlink_upper(dentry); 8185f8415d6SAmir Goldstein revert_creds(old_cred); 8195f8415d6SAmir Goldstein 8205f8415d6SAmir Goldstein out: 8215f8415d6SAmir Goldstein if (err) 8221e92e307SAmir Goldstein ovl_inode_unlock(inode); 8235f8415d6SAmir Goldstein 8245f8415d6SAmir Goldstein return err; 8255f8415d6SAmir Goldstein } 8265f8415d6SAmir Goldstein 8270e32992fSAmir Goldstein void ovl_nlink_end(struct dentry *dentry) 8285f8415d6SAmir Goldstein { 8291e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 8301e92e307SAmir Goldstein 8311e92e307SAmir Goldstein if (ovl_test_flag(OVL_INDEX, inode) && inode->i_nlink == 0) { 832caf70cb2SAmir Goldstein const struct cred *old_cred; 833caf70cb2SAmir Goldstein 834caf70cb2SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 835caf70cb2SAmir Goldstein ovl_cleanup_index(dentry); 836caf70cb2SAmir Goldstein revert_creds(old_cred); 837caf70cb2SAmir Goldstein } 838caf70cb2SAmir Goldstein 8391e92e307SAmir Goldstein ovl_inode_unlock(inode); 8405f8415d6SAmir Goldstein } 8415820dc08SAmir Goldstein 8425820dc08SAmir Goldstein int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir) 8435820dc08SAmir Goldstein { 8445820dc08SAmir Goldstein /* Workdir should not be the same as upperdir */ 8455820dc08SAmir Goldstein if (workdir == upperdir) 8465820dc08SAmir Goldstein goto err; 8475820dc08SAmir Goldstein 8485820dc08SAmir Goldstein /* Workdir should not be subdir of upperdir and vice versa */ 8495820dc08SAmir Goldstein if (lock_rename(workdir, upperdir) != NULL) 8505820dc08SAmir Goldstein goto err_unlock; 8515820dc08SAmir Goldstein 8525820dc08SAmir Goldstein return 0; 8535820dc08SAmir Goldstein 8545820dc08SAmir Goldstein err_unlock: 8555820dc08SAmir Goldstein unlock_rename(workdir, upperdir); 8565820dc08SAmir Goldstein err: 8571bd0a3aeSlijiazi pr_err("failed to lock workdir+upperdir\n"); 8585820dc08SAmir Goldstein return -EIO; 8595820dc08SAmir Goldstein } 8609d3dfea3SVivek Goyal 8619d3dfea3SVivek Goyal /* err < 0, 0 if no metacopy xattr, 1 if metacopy xattr found */ 862610afc0bSMiklos Szeredi int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct dentry *dentry) 8639d3dfea3SVivek Goyal { 8649d3dfea3SVivek Goyal int res; 8659d3dfea3SVivek Goyal 8669d3dfea3SVivek Goyal /* Only regular files can have metacopy xattr */ 8679d3dfea3SVivek Goyal if (!S_ISREG(d_inode(dentry)->i_mode)) 8689d3dfea3SVivek Goyal return 0; 8699d3dfea3SVivek Goyal 870610afc0bSMiklos Szeredi res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_METACOPY, NULL, 0); 8719d3dfea3SVivek Goyal if (res < 0) { 8729d3dfea3SVivek Goyal if (res == -ENODATA || res == -EOPNOTSUPP) 8739d3dfea3SVivek Goyal return 0; 87487b2c60cSMiklos Szeredi /* 87587b2c60cSMiklos Szeredi * getxattr on user.* may fail with EACCES in case there's no 87687b2c60cSMiklos Szeredi * read permission on the inode. Not much we can do, other than 87787b2c60cSMiklos Szeredi * tell the caller that this is not a metacopy inode. 87887b2c60cSMiklos Szeredi */ 87987b2c60cSMiklos Szeredi if (ofs->config.userxattr && res == -EACCES) 88087b2c60cSMiklos Szeredi return 0; 8819d3dfea3SVivek Goyal goto out; 8829d3dfea3SVivek Goyal } 8839d3dfea3SVivek Goyal 8849d3dfea3SVivek Goyal return 1; 8859d3dfea3SVivek Goyal out: 8861bd0a3aeSlijiazi pr_warn_ratelimited("failed to get metacopy (%i)\n", res); 8879d3dfea3SVivek Goyal return res; 8889d3dfea3SVivek Goyal } 88967d756c2SVivek Goyal 89067d756c2SVivek Goyal bool ovl_is_metacopy_dentry(struct dentry *dentry) 89167d756c2SVivek Goyal { 89267d756c2SVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 89367d756c2SVivek Goyal 89467d756c2SVivek Goyal if (!d_is_reg(dentry)) 89567d756c2SVivek Goyal return false; 89667d756c2SVivek Goyal 89767d756c2SVivek Goyal if (ovl_dentry_upper(dentry)) { 89867d756c2SVivek Goyal if (!ovl_has_upperdata(d_inode(dentry))) 89967d756c2SVivek Goyal return true; 90067d756c2SVivek Goyal return false; 90167d756c2SVivek Goyal } 90267d756c2SVivek Goyal 90367d756c2SVivek Goyal return (oe->numlower > 1); 90467d756c2SVivek Goyal } 9050a2d0d3fSVivek Goyal 906610afc0bSMiklos Szeredi char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry, 907610afc0bSMiklos Szeredi int padding) 9080a2d0d3fSVivek Goyal { 9090a2d0d3fSVivek Goyal int res; 9100a2d0d3fSVivek Goyal char *s, *next, *buf = NULL; 9110a2d0d3fSVivek Goyal 912610afc0bSMiklos Szeredi res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_REDIRECT, NULL, 0); 91392f0d6c9SMiklos Szeredi if (res == -ENODATA || res == -EOPNOTSUPP) 9140a2d0d3fSVivek Goyal return NULL; 9150a2d0d3fSVivek Goyal if (res < 0) 91692f0d6c9SMiklos Szeredi goto fail; 91792f0d6c9SMiklos Szeredi if (res == 0) 91892f0d6c9SMiklos Szeredi goto invalid; 91992f0d6c9SMiklos Szeredi 92092f0d6c9SMiklos Szeredi buf = kzalloc(res + padding + 1, GFP_KERNEL); 92192f0d6c9SMiklos Szeredi if (!buf) 92292f0d6c9SMiklos Szeredi return ERR_PTR(-ENOMEM); 92392f0d6c9SMiklos Szeredi 924610afc0bSMiklos Szeredi res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_REDIRECT, buf, res); 92592f0d6c9SMiklos Szeredi if (res < 0) 92692f0d6c9SMiklos Szeredi goto fail; 9270a2d0d3fSVivek Goyal if (res == 0) 9280a2d0d3fSVivek Goyal goto invalid; 9290a2d0d3fSVivek Goyal 9300a2d0d3fSVivek Goyal if (buf[0] == '/') { 9310a2d0d3fSVivek Goyal for (s = buf; *s++ == '/'; s = next) { 9320a2d0d3fSVivek Goyal next = strchrnul(s, '/'); 9330a2d0d3fSVivek Goyal if (s == next) 9340a2d0d3fSVivek Goyal goto invalid; 9350a2d0d3fSVivek Goyal } 9360a2d0d3fSVivek Goyal } else { 9370a2d0d3fSVivek Goyal if (strchr(buf, '/') != NULL) 9380a2d0d3fSVivek Goyal goto invalid; 9390a2d0d3fSVivek Goyal } 9400a2d0d3fSVivek Goyal 9410a2d0d3fSVivek Goyal return buf; 9420a2d0d3fSVivek Goyal invalid: 9431bd0a3aeSlijiazi pr_warn_ratelimited("invalid redirect (%s)\n", buf); 9440a2d0d3fSVivek Goyal res = -EINVAL; 94592f0d6c9SMiklos Szeredi goto err_free; 94692f0d6c9SMiklos Szeredi fail: 94792f0d6c9SMiklos Szeredi pr_warn_ratelimited("failed to get redirect (%i)\n", res); 94892f0d6c9SMiklos Szeredi err_free: 949993a0b2aSVivek Goyal kfree(buf); 950993a0b2aSVivek Goyal return ERR_PTR(res); 9510a2d0d3fSVivek Goyal } 952335d3fc5SSargun Dhillon 953335d3fc5SSargun Dhillon /* 954335d3fc5SSargun Dhillon * ovl_sync_status() - Check fs sync status for volatile mounts 955335d3fc5SSargun Dhillon * 956335d3fc5SSargun Dhillon * Returns 1 if this is not a volatile mount and a real sync is required. 957335d3fc5SSargun Dhillon * 958335d3fc5SSargun Dhillon * Returns 0 if syncing can be skipped because mount is volatile, and no errors 959335d3fc5SSargun Dhillon * have occurred on the upperdir since the mount. 960335d3fc5SSargun Dhillon * 961335d3fc5SSargun Dhillon * Returns -errno if it is a volatile mount, and the error that occurred since 962335d3fc5SSargun Dhillon * the last mount. If the error code changes, it'll return the latest error 963335d3fc5SSargun Dhillon * code. 964335d3fc5SSargun Dhillon */ 965335d3fc5SSargun Dhillon 966335d3fc5SSargun Dhillon int ovl_sync_status(struct ovl_fs *ofs) 967335d3fc5SSargun Dhillon { 968335d3fc5SSargun Dhillon struct vfsmount *mnt; 969335d3fc5SSargun Dhillon 970335d3fc5SSargun Dhillon if (ovl_should_sync(ofs)) 971335d3fc5SSargun Dhillon return 1; 972335d3fc5SSargun Dhillon 973335d3fc5SSargun Dhillon mnt = ovl_upper_mnt(ofs); 974335d3fc5SSargun Dhillon if (!mnt) 975335d3fc5SSargun Dhillon return 0; 976335d3fc5SSargun Dhillon 977335d3fc5SSargun Dhillon return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq); 978335d3fc5SSargun Dhillon } 979