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 * @dir: expected parent directory inode 25 * @name: expexted name 26 * @dentry: dentry to check 27 * @flags: lookup flags 28 * 29 * Check to make sure the lookup necessary to arrive at this inode from its 30 * parent is still good. 31 * 32 * Returns: 1 if the dentry is ok, 0 if it isn't 33 */ 34 35 static int gfs2_drevalidate(struct inode *dir, const struct qstr *name, 36 struct dentry *dentry, unsigned int flags) 37 { 38 struct dentry *parent; 39 struct gfs2_sbd *sdp; 40 struct gfs2_inode *dip; 41 struct inode *inode; 42 struct gfs2_holder d_gh; 43 struct gfs2_inode *ip = NULL; 44 int error, valid = 0; 45 int had_lock = 0; 46 47 if (flags & LOOKUP_RCU) 48 return -ECHILD; 49 50 parent = dget_parent(dentry); 51 sdp = GFS2_SB(d_inode(parent)); 52 dip = GFS2_I(d_inode(parent)); 53 inode = d_inode(dentry); 54 55 if (inode) { 56 if (is_bad_inode(inode)) 57 goto out; 58 ip = GFS2_I(inode); 59 } 60 61 if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL) { 62 valid = 1; 63 goto out; 64 } 65 66 had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL); 67 if (!had_lock) { 68 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); 69 if (error) 70 goto out; 71 } 72 73 error = gfs2_dir_check(d_inode(parent), &dentry->d_name, ip); 74 valid = inode ? !error : (error == -ENOENT); 75 76 if (!had_lock) 77 gfs2_glock_dq_uninit(&d_gh); 78 out: 79 dput(parent); 80 return valid; 81 } 82 83 static int gfs2_dhash(const struct dentry *dentry, struct qstr *str) 84 { 85 str->hash = gfs2_disk_hash(str->name, str->len); 86 return 0; 87 } 88 89 static int gfs2_dentry_delete(const struct dentry *dentry) 90 { 91 struct gfs2_inode *ginode; 92 93 if (d_really_is_negative(dentry)) 94 return 0; 95 96 ginode = GFS2_I(d_inode(dentry)); 97 if (!gfs2_holder_initialized(&ginode->i_iopen_gh)) 98 return 0; 99 100 if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags)) 101 return 1; 102 103 return 0; 104 } 105 106 const struct dentry_operations gfs2_dops = { 107 .d_revalidate = gfs2_drevalidate, 108 .d_hash = gfs2_dhash, 109 .d_delete = gfs2_dentry_delete, 110 }; 111 112