1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or https://opensource.org/licenses/CDDL-1.0.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (C) 2011 Lawrence Livermore National Security, LLC.
24 */
25
26 #ifndef _ZFS_DCACHE_H
27 #define _ZFS_DCACHE_H
28
29 #include <linux/dcache.h>
30
31 #define dname(dentry) ((char *)((dentry)->d_name.name))
32 #define dlen(dentry) ((int)((dentry)->d_name.len))
33
34 #define d_alias d_u.d_alias
35
36 /*
37 * Starting from Linux 5.13, flush_dcache_page() becomes an inline function
38 * and under some configurations, may indirectly referencing GPL-only
39 * symbols, e.g., cpu_feature_keys on powerpc and PageHuge on riscv.
40 * Override this function when it is detected being GPL-only.
41 */
42 #if defined __powerpc__ && defined HAVE_FLUSH_DCACHE_PAGE_GPL_ONLY
43 #include <linux/simd_powerpc.h>
44 #define flush_dcache_page(page) do { \
45 if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) && \
46 test_bit(PG_dcache_clean, &(page)->flags)) \
47 clear_bit(PG_dcache_clean, &(page)->flags); \
48 } while (0)
49 #endif
50 /*
51 * For riscv implementation, the use of PageHuge can be safely removed.
52 * Because it handles pages allocated by HugeTLB, while flush_dcache_page
53 * in zfs module is only called on kernel pages.
54 */
55 #if defined __riscv && defined HAVE_FLUSH_DCACHE_PAGE_GPL_ONLY
56 #define flush_dcache_page(page) do { \
57 if (test_bit(PG_dcache_clean, &(page)->flags)) \
58 clear_bit(PG_dcache_clean, &(page)->flags); \
59 } while (0)
60 #endif
61
62 /*
63 * 2.6.30 API change,
64 * The const keyword was added to the 'struct dentry_operations' in
65 * the dentry structure. To handle this we define an appropriate
66 * dentry_operations_t typedef which can be used.
67 */
68 typedef const struct dentry_operations dentry_operations_t;
69
70 /*
71 * 2.6.38 API addition,
72 * Added d_clear_d_op() helper function which clears some flags and the
73 * registered dentry->d_op table. This is required because d_set_d_op()
74 * issues a warning when the dentry operations table is already set.
75 * For the .zfs control directory to work properly we must be able to
76 * override the default operations table and register custom .d_automount
77 * and .d_revalidate callbacks.
78 */
79 static inline void
d_clear_d_op(struct dentry * dentry)80 d_clear_d_op(struct dentry *dentry)
81 {
82 dentry->d_op = NULL;
83 dentry->d_flags &= ~(
84 DCACHE_OP_HASH | DCACHE_OP_COMPARE |
85 DCACHE_OP_REVALIDATE | DCACHE_OP_DELETE);
86 }
87
88 /*
89 * Walk and invalidate all dentry aliases of an inode
90 * unless it's a mountpoint
91 */
92 static inline void
zpl_d_drop_aliases(struct inode * inode)93 zpl_d_drop_aliases(struct inode *inode)
94 {
95 struct dentry *dentry;
96 spin_lock(&inode->i_lock);
97 hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
98 if (!IS_ROOT(dentry) && !d_mountpoint(dentry) &&
99 (dentry->d_inode == inode)) {
100 d_drop(dentry);
101 }
102 }
103 spin_unlock(&inode->i_lock);
104 }
105 #endif /* _ZFS_DCACHE_H */
106