1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. 4 * 5 * This copyrighted material is made available to anyone wishing to use, 6 * modify, copy, or redistribute it subject to the terms and conditions 7 * of the GNU General Public License version 2. 8 */ 9 10 #include <linux/spinlock.h> 11 #include <linux/completion.h> 12 #include <linux/buffer_head.h> 13 #include <linux/gfs2_ondisk.h> 14 #include <linux/namei.h> 15 #include <linux/crc32.h> 16 17 #include "gfs2.h" 18 #include "incore.h" 19 #include "dir.h" 20 #include "glock.h" 21 #include "super.h" 22 #include "util.h" 23 #include "inode.h" 24 25 /** 26 * gfs2_drevalidate - Check directory lookup consistency 27 * @dentry: the mapping to check 28 * @flags: lookup flags 29 * 30 * Check to make sure the lookup necessary to arrive at this inode from its 31 * parent is still good. 32 * 33 * Returns: 1 if the dentry is ok, 0 if it isn't 34 */ 35 36 static int gfs2_drevalidate(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; 45 int had_lock = 0; 46 47 if (flags & LOOKUP_RCU) 48 return -ECHILD; 49 50 parent = dget_parent(dentry); 51 sdp = GFS2_SB(parent->d_inode); 52 dip = GFS2_I(parent->d_inode); 53 inode = dentry->d_inode; 54 55 if (inode) { 56 if (is_bad_inode(inode)) 57 goto invalid; 58 ip = GFS2_I(inode); 59 } 60 61 if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL) 62 goto valid; 63 64 had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL); 65 if (!had_lock) { 66 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); 67 if (error) 68 goto fail; 69 } 70 71 error = gfs2_dir_check(parent->d_inode, &dentry->d_name, ip); 72 switch (error) { 73 case 0: 74 if (!inode) 75 goto invalid_gunlock; 76 break; 77 case -ENOENT: 78 if (!inode) 79 goto valid_gunlock; 80 goto invalid_gunlock; 81 default: 82 goto fail_gunlock; 83 } 84 85 valid_gunlock: 86 if (!had_lock) 87 gfs2_glock_dq_uninit(&d_gh); 88 valid: 89 dput(parent); 90 return 1; 91 92 invalid_gunlock: 93 if (!had_lock) 94 gfs2_glock_dq_uninit(&d_gh); 95 invalid: 96 if (check_submounts_and_drop(dentry) != 0) 97 goto valid; 98 99 dput(parent); 100 return 0; 101 102 fail_gunlock: 103 gfs2_glock_dq_uninit(&d_gh); 104 fail: 105 dput(parent); 106 return 0; 107 } 108 109 static int gfs2_dhash(const struct dentry *dentry, struct qstr *str) 110 { 111 str->hash = gfs2_disk_hash(str->name, str->len); 112 return 0; 113 } 114 115 static int gfs2_dentry_delete(const struct dentry *dentry) 116 { 117 struct gfs2_inode *ginode; 118 119 if (!dentry->d_inode) 120 return 0; 121 122 ginode = GFS2_I(dentry->d_inode); 123 if (!ginode->i_iopen_gh.gh_gl) 124 return 0; 125 126 if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags)) 127 return 1; 128 129 return 0; 130 } 131 132 const struct dentry_operations gfs2_dops = { 133 .d_revalidate = gfs2_drevalidate, 134 .d_hash = gfs2_dhash, 135 .d_delete = gfs2_dentry_delete, 136 }; 137 138