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 #ifndef HAVE_D_MAKE_ROOT
35 #define d_make_root(inode) d_alloc_root(inode)
36 #endif /* HAVE_D_MAKE_ROOT */
37
38 #ifdef HAVE_DENTRY_D_U_ALIASES
39 #define d_alias d_u.d_alias
40 #endif
41
42 /*
43 * Starting from Linux 5.13, flush_dcache_page() becomes an inline function
44 * and under some configurations, may indirectly referencing GPL-only
45 * symbols, e.g., cpu_feature_keys on powerpc and PageHuge on riscv.
46 * Override this function when it is detected being GPL-only.
47 */
48 #if defined __powerpc__ && defined HAVE_FLUSH_DCACHE_PAGE_GPL_ONLY
49 #include <linux/simd_powerpc.h>
50 #define flush_dcache_page(page) do { \
51 if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) && \
52 test_bit(PG_dcache_clean, &(page)->flags)) \
53 clear_bit(PG_dcache_clean, &(page)->flags); \
54 } while (0)
55 #endif
56 /*
57 * For riscv implementation, the use of PageHuge can be safely removed.
58 * Because it handles pages allocated by HugeTLB, while flush_dcache_page
59 * in zfs module is only called on kernel pages.
60 */
61 #if defined __riscv && defined HAVE_FLUSH_DCACHE_PAGE_GPL_ONLY
62 #define flush_dcache_page(page) do { \
63 if (test_bit(PG_dcache_clean, &(page)->flags)) \
64 clear_bit(PG_dcache_clean, &(page)->flags); \
65 } while (0)
66 #endif
67
68 /*
69 * 2.6.30 API change,
70 * The const keyword was added to the 'struct dentry_operations' in
71 * the dentry structure. To handle this we define an appropriate
72 * dentry_operations_t typedef which can be used.
73 */
74 typedef const struct dentry_operations dentry_operations_t;
75
76 /*
77 * 2.6.38 API addition,
78 * Added d_clear_d_op() helper function which clears some flags and the
79 * registered dentry->d_op table. This is required because d_set_d_op()
80 * issues a warning when the dentry operations table is already set.
81 * For the .zfs control directory to work properly we must be able to
82 * override the default operations table and register custom .d_automount
83 * and .d_revalidate callbacks.
84 */
85 static inline void
d_clear_d_op(struct dentry * dentry)86 d_clear_d_op(struct dentry *dentry)
87 {
88 dentry->d_op = NULL;
89 dentry->d_flags &= ~(
90 DCACHE_OP_HASH | DCACHE_OP_COMPARE |
91 DCACHE_OP_REVALIDATE | DCACHE_OP_DELETE);
92 }
93
94 /*
95 * Walk and invalidate all dentry aliases of an inode
96 * unless it's a mountpoint
97 */
98 static inline void
zpl_d_drop_aliases(struct inode * inode)99 zpl_d_drop_aliases(struct inode *inode)
100 {
101 struct dentry *dentry;
102 spin_lock(&inode->i_lock);
103 hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
104 if (!IS_ROOT(dentry) && !d_mountpoint(dentry) &&
105 (dentry->d_inode == inode)) {
106 d_drop(dentry);
107 }
108 }
109 spin_unlock(&inode->i_lock);
110 }
111 #endif /* _ZFS_DCACHE_H */
112