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 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 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