| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 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(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 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(d_inode(parent), &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 | dput(parent); |
| 97 | return 0; |
| 98 | |
| 99 | fail_gunlock: |
| 100 | gfs2_glock_dq_uninit(&d_gh); |
| 101 | fail: |
| 102 | dput(parent); |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | static int gfs2_dhash(const struct dentry *dentry, struct qstr *str) |
| 107 | { |
| 108 | str->hash = gfs2_disk_hash(str->name, str->len); |
| 109 | return 0; |
| 110 | } |
| 111 | |
| 112 | static int gfs2_dentry_delete(const struct dentry *dentry) |
| 113 | { |
| 114 | struct gfs2_inode *ginode; |
| 115 | |
| 116 | if (d_really_is_negative(dentry)) |
| 117 | return 0; |
| 118 | |
| 119 | ginode = GFS2_I(d_inode(dentry)); |
| 120 | if (!gfs2_holder_initialized(&ginode->i_iopen_gh)) |
| 121 | return 0; |
| 122 | |
| 123 | if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags)) |
| 124 | return 1; |
| 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | const struct dentry_operations gfs2_dops = { |
| 130 | .d_revalidate = gfs2_drevalidate, |
| 131 | .d_hash = gfs2_dhash, |
| 132 | .d_delete = gfs2_dentry_delete, |
| 133 | }; |
| 134 | |