mirror_zfs/include/os/linux/kernel/linux/dcache_compat.h
Shengqi Chen 86239a5b9c
compact: workaround for GPL-only symbols on riscv from Linux 6.2
Since Linux 6.2, the implementation of flush_dcache_page on riscv
references GPL-only symbol `PageHuge`, breaking the build of zfs.

This patch uses existing mechanism to override flush_dcache_page,
removing the call to `PageHuge`. According to comments in kernel,
it is only used to do some check against HugeTLB pages, which only
exist in userspace. ZFS uses flush_dcache_page only on kernel pages,
thus this patch will not introduce any behaviour change.

See also: torvalds/linux@d33deda, openzfs/zfs@589f59b

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Shengqi Chen <harry-chen@outlook.com>
Closes #14974 
Closes #15627
2023-12-06 12:37:50 -08:00

112 lines
3.5 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (C) 2011 Lawrence Livermore National Security, LLC.
*/
#ifndef _ZFS_DCACHE_H
#define _ZFS_DCACHE_H
#include <linux/dcache.h>
#define dname(dentry) ((char *)((dentry)->d_name.name))
#define dlen(dentry) ((int)((dentry)->d_name.len))
#ifndef HAVE_D_MAKE_ROOT
#define d_make_root(inode) d_alloc_root(inode)
#endif /* HAVE_D_MAKE_ROOT */
#ifdef HAVE_DENTRY_D_U_ALIASES
#define d_alias d_u.d_alias
#endif
/*
* Starting from Linux 5.13, flush_dcache_page() becomes an inline function
* and under some configurations, may indirectly referencing GPL-only
* symbols, e.g., cpu_feature_keys on powerpc and PageHuge on riscv.
* Override this function when it is detected being GPL-only.
*/
#if defined __powerpc__ && defined HAVE_FLUSH_DCACHE_PAGE_GPL_ONLY
#include <linux/simd_powerpc.h>
#define flush_dcache_page(page) do { \
if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) && \
test_bit(PG_dcache_clean, &(page)->flags)) \
clear_bit(PG_dcache_clean, &(page)->flags); \
} while (0)
#endif
/*
* For riscv implementation, the use of PageHuge can be safely removed.
* Because it handles pages allocated by HugeTLB, while flush_dcache_page
* in zfs module is only called on kernel pages.
*/
#if defined __riscv && defined HAVE_FLUSH_DCACHE_PAGE_GPL_ONLY
#define flush_dcache_page(page) do { \
if (test_bit(PG_dcache_clean, &(page)->flags)) \
clear_bit(PG_dcache_clean, &(page)->flags); \
} while (0)
#endif
/*
* 2.6.30 API change,
* The const keyword was added to the 'struct dentry_operations' in
* the dentry structure. To handle this we define an appropriate
* dentry_operations_t typedef which can be used.
*/
typedef const struct dentry_operations dentry_operations_t;
/*
* 2.6.38 API addition,
* Added d_clear_d_op() helper function which clears some flags and the
* registered dentry->d_op table. This is required because d_set_d_op()
* issues a warning when the dentry operations table is already set.
* For the .zfs control directory to work properly we must be able to
* override the default operations table and register custom .d_automount
* and .d_revalidate callbacks.
*/
static inline void
d_clear_d_op(struct dentry *dentry)
{
dentry->d_op = NULL;
dentry->d_flags &= ~(
DCACHE_OP_HASH | DCACHE_OP_COMPARE |
DCACHE_OP_REVALIDATE | DCACHE_OP_DELETE);
}
/*
* Walk and invalidate all dentry aliases of an inode
* unless it's a mountpoint
*/
static inline void
zpl_d_drop_aliases(struct inode *inode)
{
struct dentry *dentry;
spin_lock(&inode->i_lock);
hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
if (!IS_ROOT(dentry) && !d_mountpoint(dentry) &&
(dentry->d_inode == inode)) {
d_drop(dentry);
}
}
spin_unlock(&inode->i_lock);
}
#endif /* _ZFS_DCACHE_H */