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; 21bbb1e54dSMiklos Szeredi return mnt_want_write(ofs->upper_mnt); 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; 27bbb1e54dSMiklos Szeredi mnt_drop_write(ofs->upper_mnt); 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 { 539df085f3SAmir Goldstein if (!sb->s_export_op || !sb->s_export_op->fh_to_dentry) 54e487d889SAmir Goldstein return 0; 55e487d889SAmir Goldstein 56e487d889SAmir Goldstein return sb->s_export_op->encode_fh ? -1 : FILEID_INO32_GEN; 5702bcd157SAmir Goldstein } 5802bcd157SAmir Goldstein 5902bcd157SAmir Goldstein struct dentry *ovl_indexdir(struct super_block *sb) 6002bcd157SAmir Goldstein { 6102bcd157SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 6202bcd157SAmir Goldstein 6302bcd157SAmir Goldstein return ofs->indexdir; 6402bcd157SAmir Goldstein } 6502bcd157SAmir Goldstein 66f168f109SAmir Goldstein /* Index all files on copy up. For now only enabled for NFS export */ 67f168f109SAmir Goldstein bool ovl_index_all(struct super_block *sb) 68f168f109SAmir Goldstein { 69f168f109SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 70f168f109SAmir Goldstein 71f168f109SAmir Goldstein return ofs->config.nfs_export && ofs->config.index; 72f168f109SAmir Goldstein } 73f168f109SAmir Goldstein 74f168f109SAmir Goldstein /* Verify lower origin on lookup. For now only enabled for NFS export */ 75f168f109SAmir Goldstein bool ovl_verify_lower(struct super_block *sb) 76f168f109SAmir Goldstein { 77f168f109SAmir Goldstein struct ovl_fs *ofs = sb->s_fs_info; 78f168f109SAmir Goldstein 79f168f109SAmir Goldstein return ofs->config.nfs_export && ofs->config.index; 80f168f109SAmir Goldstein } 81f168f109SAmir Goldstein 82bbb1e54dSMiklos Szeredi struct ovl_entry *ovl_alloc_entry(unsigned int numlower) 83bbb1e54dSMiklos Szeredi { 84bbb1e54dSMiklos Szeredi size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); 85bbb1e54dSMiklos Szeredi struct ovl_entry *oe = kzalloc(size, GFP_KERNEL); 86bbb1e54dSMiklos Szeredi 87bbb1e54dSMiklos Szeredi if (oe) 88bbb1e54dSMiklos Szeredi oe->numlower = numlower; 89bbb1e54dSMiklos Szeredi 90bbb1e54dSMiklos Szeredi return oe; 91bbb1e54dSMiklos Szeredi } 92bbb1e54dSMiklos Szeredi 93bbb1e54dSMiklos Szeredi bool ovl_dentry_remote(struct dentry *dentry) 94bbb1e54dSMiklos Szeredi { 95bbb1e54dSMiklos Szeredi return dentry->d_flags & 967925dad8SMiklos Szeredi (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); 97bbb1e54dSMiklos Szeredi } 98bbb1e54dSMiklos Szeredi 99f4288844SMiklos Szeredi void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, 100f4288844SMiklos Szeredi unsigned int mask) 101f4288844SMiklos Szeredi { 102f4288844SMiklos Szeredi struct ovl_entry *oe = OVL_E(dentry); 103f4288844SMiklos Szeredi unsigned int i, flags = 0; 104f4288844SMiklos Szeredi 105f4288844SMiklos Szeredi for (i = 0; i < oe->numlower; i++) 106f4288844SMiklos Szeredi flags |= oe->lowerstack[i].dentry->d_flags; 107f4288844SMiklos Szeredi 108f4288844SMiklos Szeredi spin_lock(&dentry->d_lock); 109f4288844SMiklos Szeredi dentry->d_flags &= ~mask; 110f4288844SMiklos Szeredi dentry->d_flags |= flags & mask; 111f4288844SMiklos Szeredi spin_unlock(&dentry->d_lock); 112f4288844SMiklos Szeredi } 113f4288844SMiklos Szeredi 114bbb1e54dSMiklos Szeredi bool ovl_dentry_weird(struct dentry *dentry) 115bbb1e54dSMiklos Szeredi { 116bbb1e54dSMiklos Szeredi return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT | 117bbb1e54dSMiklos Szeredi DCACHE_MANAGE_TRANSIT | 118bbb1e54dSMiklos Szeredi DCACHE_OP_HASH | 119bbb1e54dSMiklos Szeredi DCACHE_OP_COMPARE); 120bbb1e54dSMiklos Szeredi } 121bbb1e54dSMiklos Szeredi 122bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_type(struct dentry *dentry) 123bbb1e54dSMiklos Szeredi { 124bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 125bbb1e54dSMiklos Szeredi enum ovl_path_type type = 0; 126bbb1e54dSMiklos Szeredi 12709d8b586SMiklos Szeredi if (ovl_dentry_upper(dentry)) { 128bbb1e54dSMiklos Szeredi type = __OVL_PATH_UPPER; 129bbb1e54dSMiklos Szeredi 130bbb1e54dSMiklos Szeredi /* 13159548503SAmir Goldstein * Non-dir dentry can hold lower dentry of its copy up origin. 132bbb1e54dSMiklos Szeredi */ 13359548503SAmir Goldstein if (oe->numlower) { 13460124877SVivek Goyal if (ovl_test_flag(OVL_CONST_INO, d_inode(dentry))) 13559548503SAmir Goldstein type |= __OVL_PATH_ORIGIN; 1360b17c28aSVivek Goyal if (d_is_dir(dentry) || 1370b17c28aSVivek Goyal !ovl_has_upperdata(d_inode(dentry))) 138bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 13959548503SAmir Goldstein } 140bbb1e54dSMiklos Szeredi } else { 141bbb1e54dSMiklos Szeredi if (oe->numlower > 1) 142bbb1e54dSMiklos Szeredi type |= __OVL_PATH_MERGE; 143bbb1e54dSMiklos Szeredi } 144bbb1e54dSMiklos Szeredi return type; 145bbb1e54dSMiklos Szeredi } 146bbb1e54dSMiklos Szeredi 147bbb1e54dSMiklos Szeredi void ovl_path_upper(struct dentry *dentry, struct path *path) 148bbb1e54dSMiklos Szeredi { 149bbb1e54dSMiklos Szeredi struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 150bbb1e54dSMiklos Szeredi 151bbb1e54dSMiklos Szeredi path->mnt = ofs->upper_mnt; 15209d8b586SMiklos Szeredi path->dentry = ovl_dentry_upper(dentry); 153bbb1e54dSMiklos Szeredi } 154bbb1e54dSMiklos Szeredi 155bbb1e54dSMiklos Szeredi void ovl_path_lower(struct dentry *dentry, struct path *path) 156bbb1e54dSMiklos Szeredi { 157bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 158bbb1e54dSMiklos Szeredi 159b9343632SChandan Rajendra if (oe->numlower) { 160b9343632SChandan Rajendra path->mnt = oe->lowerstack[0].layer->mnt; 161b9343632SChandan Rajendra path->dentry = oe->lowerstack[0].dentry; 162b9343632SChandan Rajendra } else { 163b9343632SChandan Rajendra *path = (struct path) { }; 164b9343632SChandan Rajendra } 165bbb1e54dSMiklos Szeredi } 166bbb1e54dSMiklos Szeredi 1674f93b426SVivek Goyal void ovl_path_lowerdata(struct dentry *dentry, struct path *path) 1684f93b426SVivek Goyal { 1694f93b426SVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 1704f93b426SVivek Goyal 1714f93b426SVivek Goyal if (oe->numlower) { 1724f93b426SVivek Goyal path->mnt = oe->lowerstack[oe->numlower - 1].layer->mnt; 1734f93b426SVivek Goyal path->dentry = oe->lowerstack[oe->numlower - 1].dentry; 1744f93b426SVivek Goyal } else { 1754f93b426SVivek Goyal *path = (struct path) { }; 1764f93b426SVivek Goyal } 1774f93b426SVivek Goyal } 1784f93b426SVivek Goyal 179bbb1e54dSMiklos Szeredi enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) 180bbb1e54dSMiklos Szeredi { 181bbb1e54dSMiklos Szeredi enum ovl_path_type type = ovl_path_type(dentry); 182bbb1e54dSMiklos Szeredi 183bbb1e54dSMiklos Szeredi if (!OVL_TYPE_UPPER(type)) 184bbb1e54dSMiklos Szeredi ovl_path_lower(dentry, path); 185bbb1e54dSMiklos Szeredi else 186bbb1e54dSMiklos Szeredi ovl_path_upper(dentry, path); 187bbb1e54dSMiklos Szeredi 188bbb1e54dSMiklos Szeredi return type; 189bbb1e54dSMiklos Szeredi } 190bbb1e54dSMiklos Szeredi 191bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_upper(struct dentry *dentry) 192bbb1e54dSMiklos Szeredi { 19309d8b586SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(d_inode(dentry))); 194bbb1e54dSMiklos Szeredi } 195bbb1e54dSMiklos Szeredi 196bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_lower(struct dentry *dentry) 197bbb1e54dSMiklos Szeredi { 198bbb1e54dSMiklos Szeredi struct ovl_entry *oe = dentry->d_fsdata; 199bbb1e54dSMiklos Szeredi 20009d8b586SMiklos Szeredi return oe->numlower ? oe->lowerstack[0].dentry : NULL; 201bbb1e54dSMiklos Szeredi } 202bbb1e54dSMiklos Szeredi 20313464165SMiklos Szeredi const struct ovl_layer *ovl_layer_lower(struct dentry *dentry) 204da309e8cSAmir Goldstein { 205da309e8cSAmir Goldstein struct ovl_entry *oe = dentry->d_fsdata; 206da309e8cSAmir Goldstein 207da309e8cSAmir Goldstein return oe->numlower ? oe->lowerstack[0].layer : NULL; 208da309e8cSAmir Goldstein } 209da309e8cSAmir Goldstein 210647d253fSVivek Goyal /* 211647d253fSVivek Goyal * ovl_dentry_lower() could return either a data dentry or metacopy dentry 212647d253fSVivek Goyal * dependig on what is stored in lowerstack[0]. At times we need to find 213647d253fSVivek Goyal * lower dentry which has data (and not metacopy dentry). This helper 214647d253fSVivek Goyal * returns the lower data dentry. 215647d253fSVivek Goyal */ 216647d253fSVivek Goyal struct dentry *ovl_dentry_lowerdata(struct dentry *dentry) 217647d253fSVivek Goyal { 218647d253fSVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 219647d253fSVivek Goyal 220647d253fSVivek Goyal return oe->numlower ? oe->lowerstack[oe->numlower - 1].dentry : NULL; 221647d253fSVivek Goyal } 222647d253fSVivek Goyal 223bbb1e54dSMiklos Szeredi struct dentry *ovl_dentry_real(struct dentry *dentry) 224bbb1e54dSMiklos Szeredi { 22509d8b586SMiklos Szeredi return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry); 226bbb1e54dSMiklos Szeredi } 227bbb1e54dSMiklos Szeredi 2281d88f183SMiklos Szeredi struct dentry *ovl_i_dentry_upper(struct inode *inode) 2291d88f183SMiklos Szeredi { 2301d88f183SMiklos Szeredi return ovl_upperdentry_dereference(OVL_I(inode)); 2311d88f183SMiklos Szeredi } 2321d88f183SMiklos Szeredi 23309d8b586SMiklos Szeredi struct inode *ovl_inode_upper(struct inode *inode) 23425b7713aSMiklos Szeredi { 2351d88f183SMiklos Szeredi struct dentry *upperdentry = ovl_i_dentry_upper(inode); 23625b7713aSMiklos Szeredi 23709d8b586SMiklos Szeredi return upperdentry ? d_inode(upperdentry) : NULL; 23825b7713aSMiklos Szeredi } 23925b7713aSMiklos Szeredi 24009d8b586SMiklos Szeredi struct inode *ovl_inode_lower(struct inode *inode) 24109d8b586SMiklos Szeredi { 24209d8b586SMiklos Szeredi return OVL_I(inode)->lower; 24309d8b586SMiklos Szeredi } 24409d8b586SMiklos Szeredi 24509d8b586SMiklos Szeredi struct inode *ovl_inode_real(struct inode *inode) 24609d8b586SMiklos Szeredi { 24709d8b586SMiklos Szeredi return ovl_inode_upper(inode) ?: ovl_inode_lower(inode); 24809d8b586SMiklos Szeredi } 24909d8b586SMiklos Szeredi 2502664bd08SVivek Goyal /* Return inode which contains lower data. Do not return metacopy */ 2512664bd08SVivek Goyal struct inode *ovl_inode_lowerdata(struct inode *inode) 2522664bd08SVivek Goyal { 2532664bd08SVivek Goyal if (WARN_ON(!S_ISREG(inode->i_mode))) 2542664bd08SVivek Goyal return NULL; 2552664bd08SVivek Goyal 2562664bd08SVivek Goyal return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode); 2572664bd08SVivek Goyal } 25809d8b586SMiklos Szeredi 2594823d49cSVivek Goyal /* Return real inode which contains data. Does not return metacopy inode */ 2604823d49cSVivek Goyal struct inode *ovl_inode_realdata(struct inode *inode) 2614823d49cSVivek Goyal { 2624823d49cSVivek Goyal struct inode *upperinode; 2634823d49cSVivek Goyal 2644823d49cSVivek Goyal upperinode = ovl_inode_upper(inode); 2654823d49cSVivek Goyal if (upperinode && ovl_has_upperdata(inode)) 2664823d49cSVivek Goyal return upperinode; 2674823d49cSVivek Goyal 2684823d49cSVivek Goyal return ovl_inode_lowerdata(inode); 2694823d49cSVivek Goyal } 2704823d49cSVivek Goyal 2714edb83bbSMiklos Szeredi struct ovl_dir_cache *ovl_dir_cache(struct inode *inode) 272bbb1e54dSMiklos Szeredi { 2734edb83bbSMiklos Szeredi return OVL_I(inode)->cache; 274bbb1e54dSMiklos Szeredi } 275bbb1e54dSMiklos Szeredi 2764edb83bbSMiklos Szeredi void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache) 277bbb1e54dSMiklos Szeredi { 2784edb83bbSMiklos Szeredi OVL_I(inode)->cache = cache; 279bbb1e54dSMiklos Szeredi } 280bbb1e54dSMiklos Szeredi 281c62520a8SAmir Goldstein void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry) 282c62520a8SAmir Goldstein { 283c62520a8SAmir Goldstein set_bit(flag, &OVL_E(dentry)->flags); 284c62520a8SAmir Goldstein } 285c62520a8SAmir Goldstein 286c62520a8SAmir Goldstein void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry) 287c62520a8SAmir Goldstein { 288c62520a8SAmir Goldstein clear_bit(flag, &OVL_E(dentry)->flags); 289c62520a8SAmir Goldstein } 290c62520a8SAmir Goldstein 291c62520a8SAmir Goldstein bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry) 292c62520a8SAmir Goldstein { 293c62520a8SAmir Goldstein return test_bit(flag, &OVL_E(dentry)->flags); 294c62520a8SAmir Goldstein } 295c62520a8SAmir Goldstein 296bbb1e54dSMiklos Szeredi bool ovl_dentry_is_opaque(struct dentry *dentry) 297bbb1e54dSMiklos Szeredi { 298c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_OPAQUE, dentry); 299bbb1e54dSMiklos Szeredi } 300bbb1e54dSMiklos Szeredi 301bbb1e54dSMiklos Szeredi bool ovl_dentry_is_whiteout(struct dentry *dentry) 302bbb1e54dSMiklos Szeredi { 303bbb1e54dSMiklos Szeredi return !dentry->d_inode && ovl_dentry_is_opaque(dentry); 304bbb1e54dSMiklos Szeredi } 305bbb1e54dSMiklos Szeredi 3065cf5b477SMiklos Szeredi void ovl_dentry_set_opaque(struct dentry *dentry) 307bbb1e54dSMiklos Szeredi { 308c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_OPAQUE, dentry); 309bbb1e54dSMiklos Szeredi } 310bbb1e54dSMiklos Szeredi 31155acc661SMiklos Szeredi /* 312aa3ff3c1SAmir Goldstein * For hard links and decoded file handles, it's possible for ovl_dentry_upper() 313aa3ff3c1SAmir Goldstein * to return positive, while there's no actual upper alias for the inode. 314aa3ff3c1SAmir Goldstein * Copy up code needs to know about the existence of the upper alias, so it 315aa3ff3c1SAmir Goldstein * can't use ovl_dentry_upper(). 31655acc661SMiklos Szeredi */ 31755acc661SMiklos Szeredi bool ovl_dentry_has_upper_alias(struct dentry *dentry) 31855acc661SMiklos Szeredi { 319c62520a8SAmir Goldstein return ovl_dentry_test_flag(OVL_E_UPPER_ALIAS, dentry); 32055acc661SMiklos Szeredi } 32155acc661SMiklos Szeredi 32255acc661SMiklos Szeredi void ovl_dentry_set_upper_alias(struct dentry *dentry) 32355acc661SMiklos Szeredi { 324c62520a8SAmir Goldstein ovl_dentry_set_flag(OVL_E_UPPER_ALIAS, dentry); 32555acc661SMiklos Szeredi } 32655acc661SMiklos Szeredi 3270c288874SVivek Goyal static bool ovl_should_check_upperdata(struct inode *inode) 3280c288874SVivek Goyal { 3290c288874SVivek Goyal if (!S_ISREG(inode->i_mode)) 3300c288874SVivek Goyal return false; 3310c288874SVivek Goyal 3320c288874SVivek Goyal if (!ovl_inode_lower(inode)) 3330c288874SVivek Goyal return false; 3340c288874SVivek Goyal 3350c288874SVivek Goyal return true; 3360c288874SVivek Goyal } 3370c288874SVivek Goyal 3380c288874SVivek Goyal bool ovl_has_upperdata(struct inode *inode) 3390c288874SVivek Goyal { 3400c288874SVivek Goyal if (!ovl_should_check_upperdata(inode)) 3410c288874SVivek Goyal return true; 3420c288874SVivek Goyal 3430c288874SVivek Goyal if (!ovl_test_flag(OVL_UPPERDATA, inode)) 3440c288874SVivek Goyal return false; 3450c288874SVivek Goyal /* 3460c288874SVivek Goyal * Pairs with smp_wmb() in ovl_set_upperdata(). Main user of 3470c288874SVivek Goyal * ovl_has_upperdata() is ovl_copy_up_meta_inode_data(). Make sure 3480c288874SVivek Goyal * if setting of OVL_UPPERDATA is visible, then effects of writes 3490c288874SVivek Goyal * before that are visible too. 3500c288874SVivek Goyal */ 3510c288874SVivek Goyal smp_rmb(); 3520c288874SVivek Goyal return true; 3530c288874SVivek Goyal } 3540c288874SVivek Goyal 3550c288874SVivek Goyal void ovl_set_upperdata(struct inode *inode) 3560c288874SVivek Goyal { 3570c288874SVivek Goyal /* 3580c288874SVivek Goyal * Pairs with smp_rmb() in ovl_has_upperdata(). Make sure 3590c288874SVivek Goyal * if OVL_UPPERDATA flag is visible, then effects of write operations 3600c288874SVivek Goyal * before it are visible as well. 3610c288874SVivek Goyal */ 3620c288874SVivek Goyal smp_wmb(); 3630c288874SVivek Goyal ovl_set_flag(OVL_UPPERDATA, inode); 3640c288874SVivek Goyal } 3650c288874SVivek Goyal 3660c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 3670c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags) 3680c288874SVivek Goyal { 3690c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 3700c288874SVivek Goyal return false; 3710c288874SVivek Goyal 3720c288874SVivek Goyal return !ovl_test_flag(OVL_UPPERDATA, d_inode(dentry)); 3730c288874SVivek Goyal } 3740c288874SVivek Goyal 3750c288874SVivek Goyal bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags) 3760c288874SVivek Goyal { 3770c288874SVivek Goyal if (!ovl_open_flags_need_copy_up(flags)) 3780c288874SVivek Goyal return false; 3790c288874SVivek Goyal 3800c288874SVivek Goyal return !ovl_has_upperdata(d_inode(dentry)); 3810c288874SVivek Goyal } 3820c288874SVivek Goyal 383a6c60655SMiklos Szeredi bool ovl_redirect_dir(struct super_block *sb) 384a6c60655SMiklos Szeredi { 385a6c60655SMiklos Szeredi struct ovl_fs *ofs = sb->s_fs_info; 386a6c60655SMiklos Szeredi 38721a22878SAmir Goldstein return ofs->config.redirect_dir && !ofs->noxattr; 388a6c60655SMiklos Szeredi } 389a6c60655SMiklos Szeredi 390a6c60655SMiklos Szeredi const char *ovl_dentry_get_redirect(struct dentry *dentry) 391a6c60655SMiklos Szeredi { 392cf31c463SMiklos Szeredi return OVL_I(d_inode(dentry))->redirect; 393a6c60655SMiklos Szeredi } 394a6c60655SMiklos Szeredi 395a6c60655SMiklos Szeredi void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect) 396a6c60655SMiklos Szeredi { 397cf31c463SMiklos Szeredi struct ovl_inode *oi = OVL_I(d_inode(dentry)); 398a6c60655SMiklos Szeredi 399cf31c463SMiklos Szeredi kfree(oi->redirect); 400cf31c463SMiklos Szeredi oi->redirect = redirect; 401a6c60655SMiklos Szeredi } 402a6c60655SMiklos Szeredi 40309d8b586SMiklos Szeredi void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) 404bbb1e54dSMiklos Szeredi { 40509d8b586SMiklos Szeredi struct inode *upperinode = d_inode(upperdentry); 406e6d2ebddSMiklos Szeredi 40709d8b586SMiklos Szeredi WARN_ON(OVL_I(inode)->__upperdentry); 40809d8b586SMiklos Szeredi 40925b7713aSMiklos Szeredi /* 41009d8b586SMiklos Szeredi * Make sure upperdentry is consistent before making it visible 41125b7713aSMiklos Szeredi */ 41225b7713aSMiklos Szeredi smp_wmb(); 41309d8b586SMiklos Szeredi OVL_I(inode)->__upperdentry = upperdentry; 41431747edaSAmir Goldstein if (inode_unhashed(inode)) { 41525b7713aSMiklos Szeredi inode->i_private = upperinode; 416bbb1e54dSMiklos Szeredi __insert_inode_hash(inode, (unsigned long) upperinode); 417bbb1e54dSMiklos Szeredi } 41825b7713aSMiklos Szeredi } 419bbb1e54dSMiklos Szeredi 420d9854c87SMiklos Szeredi static void ovl_dentry_version_inc(struct dentry *dentry, bool impurity) 421bbb1e54dSMiklos Szeredi { 42204a01ac7SMiklos Szeredi struct inode *inode = d_inode(dentry); 423bbb1e54dSMiklos Szeredi 42404a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 4254edb83bbSMiklos Szeredi /* 4264edb83bbSMiklos Szeredi * Version is used by readdir code to keep cache consistent. For merge 4274edb83bbSMiklos Szeredi * dirs all changes need to be noted. For non-merge dirs, cache only 4284edb83bbSMiklos Szeredi * contains impure (ones which have been copied up and have origins) 4294edb83bbSMiklos Szeredi * entries, so only need to note changes to impure entries. 4304edb83bbSMiklos Szeredi */ 4314edb83bbSMiklos Szeredi if (OVL_TYPE_MERGE(ovl_path_type(dentry)) || impurity) 43204a01ac7SMiklos Szeredi OVL_I(inode)->version++; 433bbb1e54dSMiklos Szeredi } 434bbb1e54dSMiklos Szeredi 435d9854c87SMiklos Szeredi void ovl_dir_modified(struct dentry *dentry, bool impurity) 436d9854c87SMiklos Szeredi { 437d9854c87SMiklos Szeredi /* Copy mtime/ctime */ 438d9854c87SMiklos Szeredi ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry)); 439d9854c87SMiklos Szeredi 440d9854c87SMiklos Szeredi ovl_dentry_version_inc(dentry, impurity); 441d9854c87SMiklos Szeredi } 442d9854c87SMiklos Szeredi 443bbb1e54dSMiklos Szeredi u64 ovl_dentry_version_get(struct dentry *dentry) 444bbb1e54dSMiklos Szeredi { 44504a01ac7SMiklos Szeredi struct inode *inode = d_inode(dentry); 446bbb1e54dSMiklos Szeredi 44704a01ac7SMiklos Szeredi WARN_ON(!inode_is_locked(inode)); 44804a01ac7SMiklos Szeredi return OVL_I(inode)->version; 449bbb1e54dSMiklos Szeredi } 450bbb1e54dSMiklos Szeredi 451bbb1e54dSMiklos Szeredi bool ovl_is_whiteout(struct dentry *dentry) 452bbb1e54dSMiklos Szeredi { 453bbb1e54dSMiklos Szeredi struct inode *inode = dentry->d_inode; 454bbb1e54dSMiklos Szeredi 455bbb1e54dSMiklos Szeredi return inode && IS_WHITEOUT(inode); 456bbb1e54dSMiklos Szeredi } 457bbb1e54dSMiklos Szeredi 458bbb1e54dSMiklos Szeredi struct file *ovl_path_open(struct path *path, int flags) 459bbb1e54dSMiklos Szeredi { 460bbb1e54dSMiklos Szeredi return dentry_open(path, flags | O_NOATIME, current_cred()); 461bbb1e54dSMiklos Szeredi } 46239d3d60aSAmir Goldstein 4630c288874SVivek Goyal /* Caller should hold ovl_inode->lock */ 4640c288874SVivek Goyal static bool ovl_already_copied_up_locked(struct dentry *dentry, int flags) 4650c288874SVivek Goyal { 4660c288874SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 4670c288874SVivek Goyal 4680c288874SVivek Goyal if (ovl_dentry_upper(dentry) && 4690c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 4700c288874SVivek Goyal !ovl_dentry_needs_data_copy_up_locked(dentry, flags)) 4710c288874SVivek Goyal return true; 4720c288874SVivek Goyal 4730c288874SVivek Goyal return false; 4740c288874SVivek Goyal } 4750c288874SVivek Goyal 4760c288874SVivek Goyal bool ovl_already_copied_up(struct dentry *dentry, int flags) 4772002df85SVivek Goyal { 4782002df85SVivek Goyal bool disconnected = dentry->d_flags & DCACHE_DISCONNECTED; 4792002df85SVivek Goyal 4802002df85SVivek Goyal /* 4812002df85SVivek Goyal * Check if copy-up has happened as well as for upper alias (in 4822002df85SVivek Goyal * case of hard links) is there. 4832002df85SVivek Goyal * 4842002df85SVivek Goyal * Both checks are lockless: 4852002df85SVivek Goyal * - false negatives: will recheck under oi->lock 4862002df85SVivek Goyal * - false positives: 4872002df85SVivek Goyal * + ovl_dentry_upper() uses memory barriers to ensure the 4882002df85SVivek Goyal * upper dentry is up-to-date 4892002df85SVivek Goyal * + ovl_dentry_has_upper_alias() relies on locking of 4902002df85SVivek Goyal * upper parent i_rwsem to prevent reordering copy-up 4912002df85SVivek Goyal * with rename. 4922002df85SVivek Goyal */ 4932002df85SVivek Goyal if (ovl_dentry_upper(dentry) && 4940c288874SVivek Goyal (ovl_dentry_has_upper_alias(dentry) || disconnected) && 4950c288874SVivek Goyal !ovl_dentry_needs_data_copy_up(dentry, flags)) 4962002df85SVivek Goyal return true; 4972002df85SVivek Goyal 4982002df85SVivek Goyal return false; 4992002df85SVivek Goyal } 5002002df85SVivek Goyal 5010c288874SVivek Goyal int ovl_copy_up_start(struct dentry *dentry, int flags) 50239d3d60aSAmir Goldstein { 5031e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 50439d3d60aSAmir Goldstein int err; 50539d3d60aSAmir Goldstein 506531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 5070c288874SVivek Goyal if (!err && ovl_already_copied_up_locked(dentry, flags)) { 50839d3d60aSAmir Goldstein err = 1; /* Already copied up */ 5091e92e307SAmir Goldstein ovl_inode_unlock(inode); 51039d3d60aSAmir Goldstein } 51139d3d60aSAmir Goldstein 51239d3d60aSAmir Goldstein return err; 51339d3d60aSAmir Goldstein } 51439d3d60aSAmir Goldstein 51539d3d60aSAmir Goldstein void ovl_copy_up_end(struct dentry *dentry) 51639d3d60aSAmir Goldstein { 5171e92e307SAmir Goldstein ovl_inode_unlock(d_inode(dentry)); 51839d3d60aSAmir Goldstein } 51982b749b2SAmir Goldstein 520b79e05aaSAmir Goldstein bool ovl_check_origin_xattr(struct dentry *dentry) 521b79e05aaSAmir Goldstein { 522b79e05aaSAmir Goldstein int res; 523b79e05aaSAmir Goldstein 524b79e05aaSAmir Goldstein res = vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0); 525b79e05aaSAmir Goldstein 526b79e05aaSAmir Goldstein /* Zero size value means "copied up but origin unknown" */ 527b79e05aaSAmir Goldstein if (res >= 0) 528b79e05aaSAmir Goldstein return true; 529b79e05aaSAmir Goldstein 530b79e05aaSAmir Goldstein return false; 531b79e05aaSAmir Goldstein } 532b79e05aaSAmir Goldstein 533f3a15685SAmir Goldstein bool ovl_check_dir_xattr(struct dentry *dentry, const char *name) 534f3a15685SAmir Goldstein { 535f3a15685SAmir Goldstein int res; 536f3a15685SAmir Goldstein char val; 537f3a15685SAmir Goldstein 538f3a15685SAmir Goldstein if (!d_is_dir(dentry)) 539f3a15685SAmir Goldstein return false; 540f3a15685SAmir Goldstein 541f3a15685SAmir Goldstein res = vfs_getxattr(dentry, name, &val, 1); 542f3a15685SAmir Goldstein if (res == 1 && val == 'y') 543f3a15685SAmir Goldstein return true; 544f3a15685SAmir Goldstein 545f3a15685SAmir Goldstein return false; 546f3a15685SAmir Goldstein } 547f3a15685SAmir Goldstein 54882b749b2SAmir Goldstein int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, 54982b749b2SAmir Goldstein const char *name, const void *value, size_t size, 55082b749b2SAmir Goldstein int xerr) 55182b749b2SAmir Goldstein { 55282b749b2SAmir Goldstein int err; 55382b749b2SAmir Goldstein struct ovl_fs *ofs = dentry->d_sb->s_fs_info; 55482b749b2SAmir Goldstein 55582b749b2SAmir Goldstein if (ofs->noxattr) 55682b749b2SAmir Goldstein return xerr; 55782b749b2SAmir Goldstein 55882b749b2SAmir Goldstein err = ovl_do_setxattr(upperdentry, name, value, size, 0); 55982b749b2SAmir Goldstein 56082b749b2SAmir Goldstein if (err == -EOPNOTSUPP) { 5611bd0a3aeSlijiazi pr_warn("cannot set %s xattr on upper\n", name); 56282b749b2SAmir Goldstein ofs->noxattr = true; 56382b749b2SAmir Goldstein return xerr; 56482b749b2SAmir Goldstein } 56582b749b2SAmir Goldstein 56682b749b2SAmir Goldstein return err; 56782b749b2SAmir Goldstein } 568f3a15685SAmir Goldstein 569f3a15685SAmir Goldstein int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry) 570f3a15685SAmir Goldstein { 571f3a15685SAmir Goldstein int err; 572f3a15685SAmir Goldstein 57313c72075SMiklos Szeredi if (ovl_test_flag(OVL_IMPURE, d_inode(dentry))) 574f3a15685SAmir Goldstein return 0; 575f3a15685SAmir Goldstein 576f3a15685SAmir Goldstein /* 577f3a15685SAmir Goldstein * Do not fail when upper doesn't support xattrs. 578f3a15685SAmir Goldstein * Upper inodes won't have origin nor redirect xattr anyway. 579f3a15685SAmir Goldstein */ 580f3a15685SAmir Goldstein err = ovl_check_setxattr(dentry, upperdentry, OVL_XATTR_IMPURE, 581f3a15685SAmir Goldstein "y", 1, 0); 582f3a15685SAmir Goldstein if (!err) 58313c72075SMiklos Szeredi ovl_set_flag(OVL_IMPURE, d_inode(dentry)); 584f3a15685SAmir Goldstein 585f3a15685SAmir Goldstein return err; 586f3a15685SAmir Goldstein } 58713c72075SMiklos Szeredi 58813c72075SMiklos Szeredi void ovl_set_flag(unsigned long flag, struct inode *inode) 58913c72075SMiklos Szeredi { 59013c72075SMiklos Szeredi set_bit(flag, &OVL_I(inode)->flags); 59113c72075SMiklos Szeredi } 59213c72075SMiklos Szeredi 5934edb83bbSMiklos Szeredi void ovl_clear_flag(unsigned long flag, struct inode *inode) 5944edb83bbSMiklos Szeredi { 5954edb83bbSMiklos Szeredi clear_bit(flag, &OVL_I(inode)->flags); 5964edb83bbSMiklos Szeredi } 5974edb83bbSMiklos Szeredi 59813c72075SMiklos Szeredi bool ovl_test_flag(unsigned long flag, struct inode *inode) 59913c72075SMiklos Szeredi { 60013c72075SMiklos Szeredi return test_bit(flag, &OVL_I(inode)->flags); 60113c72075SMiklos Szeredi } 602ad0af710SAmir Goldstein 603ad0af710SAmir Goldstein /** 604ad0af710SAmir Goldstein * Caller must hold a reference to inode to prevent it from being freed while 605ad0af710SAmir Goldstein * it is marked inuse. 606ad0af710SAmir Goldstein */ 607ad0af710SAmir Goldstein bool ovl_inuse_trylock(struct dentry *dentry) 608ad0af710SAmir Goldstein { 609ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 610ad0af710SAmir Goldstein bool locked = false; 611ad0af710SAmir Goldstein 612ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 613ad0af710SAmir Goldstein if (!(inode->i_state & I_OVL_INUSE)) { 614ad0af710SAmir Goldstein inode->i_state |= I_OVL_INUSE; 615ad0af710SAmir Goldstein locked = true; 616ad0af710SAmir Goldstein } 617ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 618ad0af710SAmir Goldstein 619ad0af710SAmir Goldstein return locked; 620ad0af710SAmir Goldstein } 621ad0af710SAmir Goldstein 622ad0af710SAmir Goldstein void ovl_inuse_unlock(struct dentry *dentry) 623ad0af710SAmir Goldstein { 624ad0af710SAmir Goldstein if (dentry) { 625ad0af710SAmir Goldstein struct inode *inode = d_inode(dentry); 626ad0af710SAmir Goldstein 627ad0af710SAmir Goldstein spin_lock(&inode->i_lock); 628ad0af710SAmir Goldstein WARN_ON(!(inode->i_state & I_OVL_INUSE)); 629ad0af710SAmir Goldstein inode->i_state &= ~I_OVL_INUSE; 630ad0af710SAmir Goldstein spin_unlock(&inode->i_lock); 631ad0af710SAmir Goldstein } 632ad0af710SAmir Goldstein } 6335f8415d6SAmir Goldstein 634146d62e5SAmir Goldstein bool ovl_is_inuse(struct dentry *dentry) 635146d62e5SAmir Goldstein { 636146d62e5SAmir Goldstein struct inode *inode = d_inode(dentry); 637146d62e5SAmir Goldstein bool inuse; 638146d62e5SAmir Goldstein 639146d62e5SAmir Goldstein spin_lock(&inode->i_lock); 640146d62e5SAmir Goldstein inuse = (inode->i_state & I_OVL_INUSE); 641146d62e5SAmir Goldstein spin_unlock(&inode->i_lock); 642146d62e5SAmir Goldstein 643146d62e5SAmir Goldstein return inuse; 644146d62e5SAmir Goldstein } 645146d62e5SAmir Goldstein 64624b33ee1SAmir Goldstein /* 64724b33ee1SAmir Goldstein * Does this overlay dentry need to be indexed on copy up? 64824b33ee1SAmir Goldstein */ 64924b33ee1SAmir Goldstein bool ovl_need_index(struct dentry *dentry) 65024b33ee1SAmir Goldstein { 65124b33ee1SAmir Goldstein struct dentry *lower = ovl_dentry_lower(dentry); 65224b33ee1SAmir Goldstein 65324b33ee1SAmir Goldstein if (!lower || !ovl_indexdir(dentry->d_sb)) 65424b33ee1SAmir Goldstein return false; 65524b33ee1SAmir Goldstein 656fbd2d207SAmir Goldstein /* Index all files for NFS export and consistency verification */ 657016b720fSAmir Goldstein if (ovl_index_all(dentry->d_sb)) 658fbd2d207SAmir Goldstein return true; 659fbd2d207SAmir Goldstein 66024b33ee1SAmir Goldstein /* Index only lower hardlinks on copy up */ 66124b33ee1SAmir Goldstein if (!d_is_dir(lower) && d_inode(lower)->i_nlink > 1) 66224b33ee1SAmir Goldstein return true; 66324b33ee1SAmir Goldstein 66424b33ee1SAmir Goldstein return false; 66524b33ee1SAmir Goldstein } 66624b33ee1SAmir Goldstein 6679f4ec904SAmir Goldstein /* Caller must hold OVL_I(inode)->lock */ 668caf70cb2SAmir Goldstein static void ovl_cleanup_index(struct dentry *dentry) 669caf70cb2SAmir Goldstein { 670e7dd0e71SAmir Goldstein struct dentry *indexdir = ovl_indexdir(dentry->d_sb); 671e7dd0e71SAmir Goldstein struct inode *dir = indexdir->d_inode; 672caf70cb2SAmir Goldstein struct dentry *lowerdentry = ovl_dentry_lower(dentry); 673caf70cb2SAmir Goldstein struct dentry *upperdentry = ovl_dentry_upper(dentry); 674caf70cb2SAmir Goldstein struct dentry *index = NULL; 675caf70cb2SAmir Goldstein struct inode *inode; 67663e13252SAmir Goldstein struct qstr name = { }; 677caf70cb2SAmir Goldstein int err; 678caf70cb2SAmir Goldstein 679caf70cb2SAmir Goldstein err = ovl_get_index_name(lowerdentry, &name); 680caf70cb2SAmir Goldstein if (err) 681caf70cb2SAmir Goldstein goto fail; 682caf70cb2SAmir Goldstein 683caf70cb2SAmir Goldstein inode = d_inode(upperdentry); 68489a17556SAmir Goldstein if (!S_ISDIR(inode->i_mode) && inode->i_nlink != 1) { 6851bd0a3aeSlijiazi pr_warn_ratelimited("cleanup linked index (%pd2, ino=%lu, nlink=%u)\n", 686caf70cb2SAmir Goldstein upperdentry, inode->i_ino, inode->i_nlink); 687caf70cb2SAmir Goldstein /* 688caf70cb2SAmir Goldstein * We either have a bug with persistent union nlink or a lower 689caf70cb2SAmir Goldstein * hardlink was added while overlay is mounted. Adding a lower 690caf70cb2SAmir Goldstein * hardlink and then unlinking all overlay hardlinks would drop 691caf70cb2SAmir Goldstein * overlay nlink to zero before all upper inodes are unlinked. 692caf70cb2SAmir Goldstein * As a safety measure, when that situation is detected, set 693caf70cb2SAmir Goldstein * the overlay nlink to the index inode nlink minus one for the 694caf70cb2SAmir Goldstein * index entry itself. 695caf70cb2SAmir Goldstein */ 696caf70cb2SAmir Goldstein set_nlink(d_inode(dentry), inode->i_nlink - 1); 697caf70cb2SAmir Goldstein ovl_set_nlink_upper(dentry); 698caf70cb2SAmir Goldstein goto out; 699caf70cb2SAmir Goldstein } 700caf70cb2SAmir Goldstein 701caf70cb2SAmir Goldstein inode_lock_nested(dir, I_MUTEX_PARENT); 702e7dd0e71SAmir Goldstein index = lookup_one_len(name.name, indexdir, name.len); 703caf70cb2SAmir Goldstein err = PTR_ERR(index); 704e7dd0e71SAmir Goldstein if (IS_ERR(index)) { 7059f4ec904SAmir Goldstein index = NULL; 706e7dd0e71SAmir Goldstein } else if (ovl_index_all(dentry->d_sb)) { 707e7dd0e71SAmir Goldstein /* Whiteout orphan index to block future open by handle */ 708e7dd0e71SAmir Goldstein err = ovl_cleanup_and_whiteout(indexdir, dir, index); 709e7dd0e71SAmir Goldstein } else { 710e7dd0e71SAmir Goldstein /* Cleanup orphan index entries */ 711e7dd0e71SAmir Goldstein err = ovl_cleanup(dir, index); 712e7dd0e71SAmir Goldstein } 7139f4ec904SAmir Goldstein 714caf70cb2SAmir Goldstein inode_unlock(dir); 715caf70cb2SAmir Goldstein if (err) 716caf70cb2SAmir Goldstein goto fail; 717caf70cb2SAmir Goldstein 718caf70cb2SAmir Goldstein out: 71963e13252SAmir Goldstein kfree(name.name); 720caf70cb2SAmir Goldstein dput(index); 721caf70cb2SAmir Goldstein return; 722caf70cb2SAmir Goldstein 723caf70cb2SAmir Goldstein fail: 7241bd0a3aeSlijiazi pr_err("cleanup index of '%pd2' failed (%i)\n", dentry, err); 725caf70cb2SAmir Goldstein goto out; 726caf70cb2SAmir Goldstein } 727caf70cb2SAmir Goldstein 7285f8415d6SAmir Goldstein /* 7295f8415d6SAmir Goldstein * Operations that change overlay inode and upper inode nlink need to be 7305f8415d6SAmir Goldstein * synchronized with copy up for persistent nlink accounting. 7315f8415d6SAmir Goldstein */ 7320e32992fSAmir Goldstein int ovl_nlink_start(struct dentry *dentry) 7335f8415d6SAmir Goldstein { 7341e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 7355f8415d6SAmir Goldstein const struct cred *old_cred; 7365f8415d6SAmir Goldstein int err; 7375f8415d6SAmir Goldstein 7381e92e307SAmir Goldstein if (WARN_ON(!inode)) 7390e32992fSAmir Goldstein return -ENOENT; 7405f8415d6SAmir Goldstein 7415f8415d6SAmir Goldstein /* 7425f8415d6SAmir Goldstein * With inodes index is enabled, we store the union overlay nlink 74324b33ee1SAmir Goldstein * in an xattr on the index inode. When whiting out an indexed lower, 7445f8415d6SAmir Goldstein * we need to decrement the overlay persistent nlink, but before the 7455f8415d6SAmir Goldstein * first copy up, we have no upper index inode to store the xattr. 7465f8415d6SAmir Goldstein * 74724b33ee1SAmir Goldstein * As a workaround, before whiteout/rename over an indexed lower, 7485f8415d6SAmir Goldstein * copy up to create the upper index. Creating the upper index will 7495f8415d6SAmir Goldstein * initialize the overlay nlink, so it could be dropped if unlink 7505f8415d6SAmir Goldstein * or rename succeeds. 7515f8415d6SAmir Goldstein * 7525f8415d6SAmir Goldstein * TODO: implement metadata only index copy up when called with 7535f8415d6SAmir Goldstein * ovl_copy_up_flags(dentry, O_PATH). 7545f8415d6SAmir Goldstein */ 75524b33ee1SAmir Goldstein if (ovl_need_index(dentry) && !ovl_dentry_has_upper_alias(dentry)) { 7565f8415d6SAmir Goldstein err = ovl_copy_up(dentry); 7575f8415d6SAmir Goldstein if (err) 7585f8415d6SAmir Goldstein return err; 7595f8415d6SAmir Goldstein } 7605f8415d6SAmir Goldstein 761531d3040SAmir Goldstein err = ovl_inode_lock_interruptible(inode); 7625f8415d6SAmir Goldstein if (err) 7635f8415d6SAmir Goldstein return err; 7645f8415d6SAmir Goldstein 7651e92e307SAmir Goldstein if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, inode)) 7665f8415d6SAmir Goldstein goto out; 7675f8415d6SAmir Goldstein 7685f8415d6SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 7695f8415d6SAmir Goldstein /* 7705f8415d6SAmir Goldstein * The overlay inode nlink should be incremented/decremented IFF the 7715f8415d6SAmir Goldstein * upper operation succeeds, along with nlink change of upper inode. 7725f8415d6SAmir Goldstein * Therefore, before link/unlink/rename, we store the union nlink 7735f8415d6SAmir Goldstein * value relative to the upper inode nlink in an upper inode xattr. 7745f8415d6SAmir Goldstein */ 7755f8415d6SAmir Goldstein err = ovl_set_nlink_upper(dentry); 7765f8415d6SAmir Goldstein revert_creds(old_cred); 7775f8415d6SAmir Goldstein 7785f8415d6SAmir Goldstein out: 7795f8415d6SAmir Goldstein if (err) 7801e92e307SAmir Goldstein ovl_inode_unlock(inode); 7815f8415d6SAmir Goldstein 7825f8415d6SAmir Goldstein return err; 7835f8415d6SAmir Goldstein } 7845f8415d6SAmir Goldstein 7850e32992fSAmir Goldstein void ovl_nlink_end(struct dentry *dentry) 7865f8415d6SAmir Goldstein { 7871e92e307SAmir Goldstein struct inode *inode = d_inode(dentry); 7881e92e307SAmir Goldstein 7891e92e307SAmir Goldstein if (ovl_test_flag(OVL_INDEX, inode) && inode->i_nlink == 0) { 790caf70cb2SAmir Goldstein const struct cred *old_cred; 791caf70cb2SAmir Goldstein 792caf70cb2SAmir Goldstein old_cred = ovl_override_creds(dentry->d_sb); 793caf70cb2SAmir Goldstein ovl_cleanup_index(dentry); 794caf70cb2SAmir Goldstein revert_creds(old_cred); 795caf70cb2SAmir Goldstein } 796caf70cb2SAmir Goldstein 7971e92e307SAmir Goldstein ovl_inode_unlock(inode); 7985f8415d6SAmir Goldstein } 7995820dc08SAmir Goldstein 8005820dc08SAmir Goldstein int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir) 8015820dc08SAmir Goldstein { 8025820dc08SAmir Goldstein /* Workdir should not be the same as upperdir */ 8035820dc08SAmir Goldstein if (workdir == upperdir) 8045820dc08SAmir Goldstein goto err; 8055820dc08SAmir Goldstein 8065820dc08SAmir Goldstein /* Workdir should not be subdir of upperdir and vice versa */ 8075820dc08SAmir Goldstein if (lock_rename(workdir, upperdir) != NULL) 8085820dc08SAmir Goldstein goto err_unlock; 8095820dc08SAmir Goldstein 8105820dc08SAmir Goldstein return 0; 8115820dc08SAmir Goldstein 8125820dc08SAmir Goldstein err_unlock: 8135820dc08SAmir Goldstein unlock_rename(workdir, upperdir); 8145820dc08SAmir Goldstein err: 8151bd0a3aeSlijiazi pr_err("failed to lock workdir+upperdir\n"); 8165820dc08SAmir Goldstein return -EIO; 8175820dc08SAmir Goldstein } 8189d3dfea3SVivek Goyal 8199d3dfea3SVivek Goyal /* err < 0, 0 if no metacopy xattr, 1 if metacopy xattr found */ 8209d3dfea3SVivek Goyal int ovl_check_metacopy_xattr(struct dentry *dentry) 8219d3dfea3SVivek Goyal { 8229d3dfea3SVivek Goyal int res; 8239d3dfea3SVivek Goyal 8249d3dfea3SVivek Goyal /* Only regular files can have metacopy xattr */ 8259d3dfea3SVivek Goyal if (!S_ISREG(d_inode(dentry)->i_mode)) 8269d3dfea3SVivek Goyal return 0; 8279d3dfea3SVivek Goyal 8289d3dfea3SVivek Goyal res = vfs_getxattr(dentry, OVL_XATTR_METACOPY, NULL, 0); 8299d3dfea3SVivek Goyal if (res < 0) { 8309d3dfea3SVivek Goyal if (res == -ENODATA || res == -EOPNOTSUPP) 8319d3dfea3SVivek Goyal return 0; 8329d3dfea3SVivek Goyal goto out; 8339d3dfea3SVivek Goyal } 8349d3dfea3SVivek Goyal 8359d3dfea3SVivek Goyal return 1; 8369d3dfea3SVivek Goyal out: 8371bd0a3aeSlijiazi pr_warn_ratelimited("failed to get metacopy (%i)\n", res); 8389d3dfea3SVivek Goyal return res; 8399d3dfea3SVivek Goyal } 84067d756c2SVivek Goyal 84167d756c2SVivek Goyal bool ovl_is_metacopy_dentry(struct dentry *dentry) 84267d756c2SVivek Goyal { 84367d756c2SVivek Goyal struct ovl_entry *oe = dentry->d_fsdata; 84467d756c2SVivek Goyal 84567d756c2SVivek Goyal if (!d_is_reg(dentry)) 84667d756c2SVivek Goyal return false; 84767d756c2SVivek Goyal 84867d756c2SVivek Goyal if (ovl_dentry_upper(dentry)) { 84967d756c2SVivek Goyal if (!ovl_has_upperdata(d_inode(dentry))) 85067d756c2SVivek Goyal return true; 85167d756c2SVivek Goyal return false; 85267d756c2SVivek Goyal } 85367d756c2SVivek Goyal 85467d756c2SVivek Goyal return (oe->numlower > 1); 85567d756c2SVivek Goyal } 8560a2d0d3fSVivek Goyal 857993a0b2aSVivek Goyal ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value, 858993a0b2aSVivek Goyal size_t padding) 859993a0b2aSVivek Goyal { 860993a0b2aSVivek Goyal ssize_t res; 861993a0b2aSVivek Goyal char *buf = NULL; 862993a0b2aSVivek Goyal 863993a0b2aSVivek Goyal res = vfs_getxattr(dentry, name, NULL, 0); 864993a0b2aSVivek Goyal if (res < 0) { 865993a0b2aSVivek Goyal if (res == -ENODATA || res == -EOPNOTSUPP) 866993a0b2aSVivek Goyal return -ENODATA; 867993a0b2aSVivek Goyal goto fail; 868993a0b2aSVivek Goyal } 869993a0b2aSVivek Goyal 870993a0b2aSVivek Goyal if (res != 0) { 871993a0b2aSVivek Goyal buf = kzalloc(res + padding, GFP_KERNEL); 872993a0b2aSVivek Goyal if (!buf) 873993a0b2aSVivek Goyal return -ENOMEM; 874993a0b2aSVivek Goyal 875993a0b2aSVivek Goyal res = vfs_getxattr(dentry, name, buf, res); 876993a0b2aSVivek Goyal if (res < 0) 877993a0b2aSVivek Goyal goto fail; 878993a0b2aSVivek Goyal } 879993a0b2aSVivek Goyal *value = buf; 880993a0b2aSVivek Goyal 881993a0b2aSVivek Goyal return res; 882993a0b2aSVivek Goyal 883993a0b2aSVivek Goyal fail: 8841bd0a3aeSlijiazi pr_warn_ratelimited("failed to get xattr %s: err=%zi)\n", 885993a0b2aSVivek Goyal name, res); 886993a0b2aSVivek Goyal kfree(buf); 887993a0b2aSVivek Goyal return res; 888993a0b2aSVivek Goyal } 889993a0b2aSVivek Goyal 8900a2d0d3fSVivek Goyal char *ovl_get_redirect_xattr(struct dentry *dentry, int padding) 8910a2d0d3fSVivek Goyal { 8920a2d0d3fSVivek Goyal int res; 8930a2d0d3fSVivek Goyal char *s, *next, *buf = NULL; 8940a2d0d3fSVivek Goyal 895993a0b2aSVivek Goyal res = ovl_getxattr(dentry, OVL_XATTR_REDIRECT, &buf, padding + 1); 896993a0b2aSVivek Goyal if (res == -ENODATA) 8970a2d0d3fSVivek Goyal return NULL; 8980a2d0d3fSVivek Goyal if (res < 0) 899993a0b2aSVivek Goyal return ERR_PTR(res); 9000a2d0d3fSVivek Goyal if (res == 0) 9010a2d0d3fSVivek Goyal goto invalid; 9020a2d0d3fSVivek Goyal 9030a2d0d3fSVivek Goyal if (buf[0] == '/') { 9040a2d0d3fSVivek Goyal for (s = buf; *s++ == '/'; s = next) { 9050a2d0d3fSVivek Goyal next = strchrnul(s, '/'); 9060a2d0d3fSVivek Goyal if (s == next) 9070a2d0d3fSVivek Goyal goto invalid; 9080a2d0d3fSVivek Goyal } 9090a2d0d3fSVivek Goyal } else { 9100a2d0d3fSVivek Goyal if (strchr(buf, '/') != NULL) 9110a2d0d3fSVivek Goyal goto invalid; 9120a2d0d3fSVivek Goyal } 9130a2d0d3fSVivek Goyal 9140a2d0d3fSVivek Goyal return buf; 9150a2d0d3fSVivek Goyal invalid: 9161bd0a3aeSlijiazi pr_warn_ratelimited("invalid redirect (%s)\n", buf); 9170a2d0d3fSVivek Goyal res = -EINVAL; 918993a0b2aSVivek Goyal kfree(buf); 919993a0b2aSVivek Goyal return ERR_PTR(res); 9200a2d0d3fSVivek Goyal } 921