1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 4 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. 5 */ 6 7 #include <linux/spinlock.h> 8 #include <linux/completion.h> 9 #include <linux/buffer_head.h> 10 #include <linux/gfs2_ondisk.h> 11 #include <linux/namei.h> 12 #include <linux/crc32.h> 13 14 #include "gfs2.h" 15 #include "incore.h" 16 #include "dir.h" 17 #include "glock.h" 18 #include "super.h" 19 #include "util.h" 20 #include "inode.h" 21 22 /** 23 * gfs2_drevalidate - Check directory lookup consistency 24 * @dentry: the mapping to check 25 * @flags: lookup flags 26 * 27 * Check to make sure the lookup necessary to arrive at this inode from its 28 * parent is still good. 29 * 30 * Returns: 1 if the dentry is ok, 0 if it isn't 31 */ 32 33 static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags) 34 { 35 struct dentry *parent; 36 struct gfs2_sbd *sdp; 37 struct gfs2_inode *dip; 38 struct inode *inode; 39 struct gfs2_holder d_gh; 40 struct gfs2_inode *ip = NULL; 41 int error; 42 int had_lock = 0; 43 44 if (flags & LOOKUP_RCU) 45 return -ECHILD; 46 47 parent = dget_parent(dentry); 48 sdp = GFS2_SB(d_inode(parent)); 49 dip = GFS2_I(d_inode(parent)); 50 inode = d_inode(dentry); 51 52 if (inode) { 53 if (is_bad_inode(inode)) 54 goto invalid; 55 ip = GFS2_I(inode); 56 } 57 58 if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL) 59 goto valid; 60 61 had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL); 62 if (!had_lock) { 63 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); 64 if (error) 65 goto fail; 66 } 67 68 error = gfs2_dir_check(d_inode(parent), &dentry->d_name, ip); 69 switch (error) { 70 case 0: 71 if (!inode) 72 goto invalid_gunlock; 73 break; 74 case -ENOENT: 75 if (!inode) 76 goto valid_gunlock; 77 goto invalid_gunlock; 78 default: 79 goto fail_gunlock; 80 } 81 82 valid_gunlock: 83 if (!had_lock) 84 gfs2_glock_dq_uninit(&d_gh); 85 valid: 86 dput(parent); 87 return 1; 88 89 invalid_gunlock: 90 if (!had_lock) 91 gfs2_glock_dq_uninit(&d_gh); 92 invalid: 93 dput(parent); 94 return 0; 95 96 fail_gunlock: 97 gfs2_glock_dq_uninit(&d_gh); 98 fail: 99 dput(parent); 100 return 0; 101 } 102 103 static int gfs2_dhash(const struct dentry *dentry, struct qstr *str) 104 { 105 str->hash = gfs2_disk_hash(str->name, str->len); 106 return 0; 107 } 108 109 static int gfs2_dentry_delete(const struct dentry *dentry) 110 { 111 struct gfs2_inode *ginode; 112 113 if (d_really_is_negative(dentry)) 114 return 0; 115 116 ginode = GFS2_I(d_inode(dentry)); 117 if (!gfs2_holder_initialized(&ginode->i_iopen_gh)) 118 return 0; 119 120 if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags)) 121 return 1; 122 123 return 0; 124 } 125 126 const struct dentry_operations gfs2_dops = { 127 .d_revalidate = gfs2_drevalidate, 128 .d_hash = gfs2_dhash, 129 .d_delete = gfs2_dentry_delete, 130 }; 131 132