enable docker ppp

hc

2023-12-09 95099d4622f8cb224d94e314c7a8e0df60b13f87

 kernel/fs/overlayfs/dir.c
..
..
@@ -1,10 +1,7 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
1
2
 /*
2
3
  *
3
4
  * Copyright (C) 2011 Novell Inc.
4
- *
5
- * This program is free software; you can redistribute it and/or modify it
6
- * under the terms of the GNU General Public License version 2 as published by
7
- * the Free Software Foundation.
8
5
  */
9
6
 
10
7
 #include <linux/fs.h>
..
..
@@ -21,7 +18,7 @@
21
18
 
22
19
 static unsigned short ovl_redirect_max = 256;
23
20
 module_param_named(redirect_max, ovl_redirect_max, ushort, 0644);
24
-MODULE_PARM_DESC(ovl_redirect_max,
21
+MODULE_PARM_DESC(redirect_max,
25
22
 		 "Maximum length of absolute redirect xattr value");
26
23
 
27
24
 static int ovl_set_redirect(struct dentry *dentry, bool samedir);
..
..
@@ -38,14 +35,14 @@
38
35
 	dput(wdentry);
39
36
 
40
37
 	if (err) {
41
-		pr_err("overlayfs: cleanup of '%pd2' failed (%i)\n",
38
+		pr_err("cleanup of '%pd2' failed (%i)\n",
42
39
 		       wdentry, err);
43
40
 	}
44
41
 
45
42
 	return err;
46
43
 }
47
44
 
48
-static struct dentry *ovl_lookup_temp(struct dentry *workdir)
45
+struct dentry *ovl_lookup_temp(struct dentry *workdir)
49
46
 {
50
47
 	struct dentry *temp;
51
48
 	char name[20];
..
..
@@ -56,7 +53,7 @@
56
53
 
57
54
 	temp = lookup_one_len(name, workdir, strlen(name));
58
55
 	if (!IS_ERR(temp) && temp->d_inode) {
59
-		pr_err("overlayfs: workdir/%s already exists\n", name);
56
+		pr_err("workdir/%s already exists\n", name);
60
57
 		dput(temp);
61
58
 		temp = ERR_PTR(-EIO);
62
59
 	}
..
..
@@ -65,35 +62,59 @@
65
62
 }
66
63
 
67
64
 /* caller holds i_mutex on workdir */
68
-static struct dentry *ovl_whiteout(struct dentry *workdir)
65
+static struct dentry *ovl_whiteout(struct ovl_fs *ofs)
69
66
 {
70
67
 	int err;
71
68
 	struct dentry *whiteout;
69
+	struct dentry *workdir = ofs->workdir;
72
70
 	struct inode *wdir = workdir->d_inode;
73
71
 
74
-	whiteout = ovl_lookup_temp(workdir);
75
-	if (IS_ERR(whiteout))
76
-		return whiteout;
72
+	if (!ofs->whiteout) {
73
+		whiteout = ovl_lookup_temp(workdir);
74
+		if (IS_ERR(whiteout))
75
+			goto out;
77
76
 
78
-	err = ovl_do_whiteout(wdir, whiteout);
79
-	if (err) {
80
-		dput(whiteout);
81
-		whiteout = ERR_PTR(err);
77
+		err = ovl_do_whiteout(wdir, whiteout);
78
+		if (err) {
79
+			dput(whiteout);
80
+			whiteout = ERR_PTR(err);
81
+			goto out;
82
+		}
83
+		ofs->whiteout = whiteout;
82
84
 	}
83
85
 
86
+	if (ofs->share_whiteout) {
87
+		whiteout = ovl_lookup_temp(workdir);
88
+		if (IS_ERR(whiteout))
89
+			goto out;
90
+
91
+		err = ovl_do_link(ofs->whiteout, wdir, whiteout);
92
+		if (!err)
93
+			goto out;
94
+
95
+		if (err != -EMLINK) {
96
+			pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%i)\n",
97
+				ofs->whiteout->d_inode->i_nlink, err);
98
+			ofs->share_whiteout = false;
99
+		}
100
+		dput(whiteout);
101
+	}
102
+	whiteout = ofs->whiteout;
103
+	ofs->whiteout = NULL;
104
+out:
84
105
 	return whiteout;
85
106
 }
86
107
 
87
108
 /* Caller must hold i_mutex on both workdir and dir */
88
-int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
109
+int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
89
110
 			     struct dentry *dentry)
90
111
 {
91
-	struct inode *wdir = workdir->d_inode;
112
+	struct inode *wdir = ofs->workdir->d_inode;
92
113
 	struct dentry *whiteout;
93
114
 	int err;
94
115
 	int flags = 0;
95
116
 
96
-	whiteout = ovl_whiteout(workdir);
117
+	whiteout = ovl_whiteout(ofs);
97
118
 	err = PTR_ERR(whiteout);
98
119
 	if (IS_ERR(whiteout))
99
120
 		return err;
..
..
@@ -136,7 +157,7 @@
136
157
 	d = lookup_one_len(dentry->d_name.name, dentry->d_parent,
137
158
 			   dentry->d_name.len);
138
159
 	if (IS_ERR(d)) {
139
-		pr_warn("overlayfs: failed lookup after mkdir (%pd2, err=%i).\n",
160
+		pr_warn("failed lookup after mkdir (%pd2, err=%i).\n",
140
161
 			dentry, err);
141
162
 		return PTR_ERR(d);
142
163
 	}
..
..
@@ -245,6 +266,9 @@
245
266
 
246
267
 	ovl_dir_modified(dentry->d_parent, false);
247
268
 	ovl_dentry_set_upper_alias(dentry);
269
+	ovl_dentry_update_reval(dentry, newdentry,
270
+			DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
271
+
248
272
 	if (!hardlink) {
249
273
 		/*
250
274
 		 * ovl_obtain_alias() can be called after ovl_create_real()
..
..
@@ -261,6 +285,8 @@
261
285
 		inode = ovl_get_inode(dentry->d_sb, &oip);
262
286
 		if (IS_ERR(inode))
263
287
 			return PTR_ERR(inode);
288
+		if (inode == oip.newinode)
289
+			ovl_set_flag(OVL_UPPERDATA, inode);
264
290
 	} else {
265
291
 		WARN_ON(ovl_inode_real(inode) != d_inode(newdentry));
266
292
 		dput(newdentry);
..
..
@@ -269,7 +295,7 @@
269
295
 
270
296
 	d_instantiate(dentry, inode);
271
297
 	if (inode != oip.newinode) {
272
-		pr_warn_ratelimited("overlayfs: newly created inode found in cache (%pd2)\n",
298
+		pr_warn_ratelimited("newly created inode found in cache (%pd2)\n",
273
299
 				    dentry);
274
300
 	}
275
301
 
..
..
@@ -367,7 +393,7 @@
367
393
 	if (IS_ERR(opaquedir))
368
394
 		goto out_unlock;
369
395
 
370
-	err = ovl_copy_xattr(upper, opaquedir);
396
+	err = ovl_copy_xattr(dentry->d_sb, upper, opaquedir);
371
397
 	if (err)
372
398
 		goto out_cleanup;
373
399
 
..
..
@@ -413,13 +439,12 @@
413
439
 	if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl)
414
440
 		return 0;
415
441
 
416
-	size = posix_acl_to_xattr(NULL, acl, NULL, 0);
442
+	size = posix_acl_xattr_size(acl->a_count);
417
443
 	buffer = kmalloc(size, GFP_KERNEL);
418
444
 	if (!buffer)
419
445
 		return -ENOMEM;
420
446
 
421
-	size = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
422
-	err = size;
447
+	err = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
423
448
 	if (err < 0)
424
449
 		goto out_free;
425
450
 
..
..
@@ -585,7 +610,7 @@
585
610
 			err = ovl_create_over_whiteout(dentry, inode, attr);
586
611
 	}
587
612
 out_revert_creds:
588
-	ovl_revert_creds(old_cred ?: hold_cred);
613
+	ovl_revert_creds(dentry->d_sb, old_cred ?: hold_cred);
589
614
 	if (old_cred && hold_cred)
590
615
 		put_cred(hold_cred);
591
616
 	return err;
..
..
@@ -663,7 +688,7 @@
663
688
 
664
689
 	old_cred = ovl_override_creds(dentry->d_sb);
665
690
 	err = ovl_set_redirect(dentry, false);
666
-	ovl_revert_creds(old_cred);
691
+	ovl_revert_creds(dentry->d_sb, old_cred);
667
692
 
668
693
 	return err;
669
694
 }
..
..
@@ -672,7 +697,6 @@
672
697
 		    struct dentry *new)
673
698
 {
674
699
 	int err;
675
-	bool locked = false;
676
700
 	struct inode *inode;
677
701
 
678
702
 	err = ovl_want_write(old);
..
..
@@ -693,7 +717,7 @@
693
717
 			goto out_drop_write;
694
718
 	}
695
719
 
696
-	err = ovl_nlink_start(old, &locked);
720
+	err = ovl_nlink_start(old);
697
721
 	if (err)
698
722
 		goto out_drop_write;
699
723
 
..
..
@@ -706,7 +730,7 @@
706
730
 	if (err)
707
731
 		iput(inode);
708
732
 
709
-	ovl_nlink_end(old, locked);
733
+	ovl_nlink_end(old);
710
734
 out_drop_write:
711
735
 	ovl_drop_write(old);
712
736
 out:
..
..
@@ -721,6 +745,7 @@
721
745
 static int ovl_remove_and_whiteout(struct dentry *dentry,
722
746
 				   struct list_head *list)
723
747
 {
748
+	struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
724
749
 	struct dentry *workdir = ovl_workdir(dentry);
725
750
 	struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
726
751
 	struct dentry *upper;
..
..
@@ -754,7 +779,7 @@
754
779
 		goto out_dput_upper;
755
780
 	}
756
781
 
757
-	err = ovl_cleanup_and_whiteout(workdir, d_inode(upperdir), upper);
782
+	err = ovl_cleanup_and_whiteout(ofs, d_inode(upperdir), upper);
758
783
 	if (err)
759
784
 		goto out_d_drop;
760
785
 
..
..
@@ -828,10 +853,31 @@
828
853
 	       !ovl_test_flag(OVL_WHITEOUTS, d_inode(dentry));
829
854
 }
830
855
 
856
+static void ovl_drop_nlink(struct dentry *dentry)
857
+{
858
+	struct inode *inode = d_inode(dentry);
859
+	struct dentry *alias;
860
+
861
+	/* Try to find another, hashed alias */
862
+	spin_lock(&inode->i_lock);
863
+	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
864
+		if (alias != dentry && !d_unhashed(alias))
865
+			break;
866
+	}
867
+	spin_unlock(&inode->i_lock);
868
+
869
+	/*
870
+	 * Changes to underlying layers may cause i_nlink to lose sync with
871
+	 * reality.  In this case prevent the link count from going to zero
872
+	 * prematurely.
873
+	 */
874
+	if (inode->i_nlink > !!alias)
875
+		drop_nlink(inode);
876
+}
877
+
831
878
 static int ovl_do_remove(struct dentry *dentry, bool is_dir)
832
879
 {
833
880
 	int err;
834
-	bool locked = false;
835
881
 	const struct cred *old_cred;
836
882
 	struct dentry *upperdentry;
837
883
 	bool lower_positive = ovl_lower_positive(dentry);
..
..
@@ -852,7 +898,7 @@
852
898
 	if (err)
853
899
 		goto out_drop_write;
854
900
 
855
-	err = ovl_nlink_start(dentry, &locked);
901
+	err = ovl_nlink_start(dentry);
856
902
 	if (err)
857
903
 		goto out_drop_write;
858
904
 
..
..
@@ -861,14 +907,14 @@
861
907
 		err = ovl_remove_upper(dentry, is_dir, &list);
862
908
 	else
863
909
 		err = ovl_remove_and_whiteout(dentry, &list);
864
-	ovl_revert_creds(old_cred);
910
+	ovl_revert_creds(dentry->d_sb, old_cred);
865
911
 	if (!err) {
866
912
 		if (is_dir)
867
913
 			clear_nlink(dentry->d_inode);
868
914
 		else
869
-			drop_nlink(dentry->d_inode);
915
+			ovl_drop_nlink(dentry);
870
916
 	}
871
-	ovl_nlink_end(dentry, locked);
917
+	ovl_nlink_end(dentry);
872
918
 
873
919
 	/*
874
920
 	 * Copy ctime
..
..
@@ -1019,7 +1065,7 @@
1019
1065
 		spin_unlock(&dentry->d_lock);
1020
1066
 	} else {
1021
1067
 		kfree(redirect);
1022
-		pr_warn_ratelimited("overlayfs: failed to set redirect (%i)\n",
1068
+		pr_warn_ratelimited("failed to set redirect (%i)\n",
1023
1069
 				    err);
1024
1070
 		/* Fall back to userspace copy-up */
1025
1071
 		err = -EXDEV;
..
..
@@ -1032,7 +1078,6 @@
1032
1078
 		      unsigned int flags)
1033
1079
 {
1034
1080
 	int err;
1035
-	bool locked = false;
1036
1081
 	struct dentry *old_upperdir;
1037
1082
 	struct dentry *new_upperdir;
1038
1083
 	struct dentry *olddentry;
..
..
@@ -1041,6 +1086,7 @@
1041
1086
 	bool old_opaque;
1042
1087
 	bool new_opaque;
1043
1088
 	bool cleanup_whiteout = false;
1089
+	bool update_nlink = false;
1044
1090
 	bool overwrite = !(flags & RENAME_EXCHANGE);
1045
1091
 	bool is_dir = d_is_dir(old);
1046
1092
 	bool new_is_dir = d_is_dir(new);
..
..
@@ -1098,10 +1144,12 @@
1098
1144
 		err = ovl_copy_up(new);
1099
1145
 		if (err)
1100
1146
 			goto out_drop_write;
1101
-	} else {
1102
-		err = ovl_nlink_start(new, &locked);
1147
+	} else if (d_inode(new)) {
1148
+		err = ovl_nlink_start(new);
1103
1149
 		if (err)
1104
1150
 			goto out_drop_write;
1151
+
1152
+		update_nlink = true;
1105
1153
 	}
1106
1154
 
1107
1155
 	old_cred = ovl_override_creds(old->d_sb);
..
..
@@ -1213,7 +1261,7 @@
1213
1261
 		if (new_is_dir)
1214
1262
 			clear_nlink(d_inode(new));
1215
1263
 		else
1216
-			drop_nlink(d_inode(new));
1264
+			ovl_drop_nlink(new);
1217
1265
 	}
1218
1266
 
1219
1267
 	ovl_dir_modified(old->d_parent, ovl_type_origin(old) ||
..
..
@@ -1233,8 +1281,9 @@
1233
1281
 out_unlock:
1234
1282
 	unlock_rename(new_upperdir, old_upperdir);
1235
1283
 out_revert_creds:
1236
-	ovl_revert_creds(old_cred);
1237
-	ovl_nlink_end(new, locked);
1284
+	ovl_revert_creds(old->d_sb, old_cred);
1285
+	if (update_nlink)
1286
+		ovl_nlink_end(new);
1238
1287
 out_drop_write:
1239
1288
 	ovl_drop_write(old);
1240
1289
 out: