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 = NULL; 36 struct gfs2_sbd *sdp; 37 struct gfs2_inode *dip; 38 struct inode *dinode, *inode; 39 struct gfs2_holder d_gh; 40 struct gfs2_inode *ip = NULL; 41 int error, valid = 0; 42 int had_lock = 0; 43 44 if (flags & LOOKUP_RCU) { 45 dinode = d_inode_rcu(READ_ONCE(dentry->d_parent)); 46 if (!dinode) 47 return -ECHILD; 48 } else { 49 parent = dget_parent(dentry); 50 dinode = d_inode(parent); 51 } 52 sdp = GFS2_SB(dinode); 53 dip = GFS2_I(dinode); 54 inode = d_inode(dentry); 55 56 if (inode) { 57 if (is_bad_inode(inode)) 58 goto out; 59 ip = GFS2_I(inode); 60 } 61 62 if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL) { 63 valid = 1; 64 goto out; 65 } 66 67 had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL); 68 if (!had_lock) { 69 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 70 flags & LOOKUP_RCU ? GL_NOBLOCK : 0, &d_gh); 71 if (error) 72 goto out; 73 } 74 75 error = gfs2_dir_check(d_inode(parent), &dentry->d_name, ip); 76 valid = inode ? !error : (error == -ENOENT); 77 78 if (!had_lock) 79 gfs2_glock_dq_uninit(&d_gh); 80 out: 81 dput(parent); 82 return valid; 83 } 84 85 static int gfs2_dhash(const struct dentry *dentry, struct qstr *str) 86 { 87 str->hash = gfs2_disk_hash(str->name, str->len); 88 return 0; 89 } 90 91 static int gfs2_dentry_delete(const struct dentry *dentry) 92 { 93 struct gfs2_inode *ginode; 94 95 if (d_really_is_negative(dentry)) 96 return 0; 97 98 ginode = GFS2_I(d_inode(dentry)); 99 if (!gfs2_holder_initialized(&ginode->i_iopen_gh)) 100 return 0; 101 102 if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags)) 103 return 1; 104 105 return 0; 106 } 107 108 const struct dentry_operations gfs2_dops = { 109 .d_revalidate = gfs2_drevalidate, 110 .d_hash = gfs2_dhash, 111 .d_delete = gfs2_dentry_delete, 112 }; 113 114