c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2026-01-13 00:32:47 +03:00
Code Issues Packages Projects Releases Wiki Activity

Linux 6.17: d_set_d_op() is no longer available

Browse Source 
We only have extremely narrow uses, so move it all into a single
function that does only what we need, with and without d_set_d_op().

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #17621
This commit is contained in:
Rob Norris 2025-07-31 13:12:43 +10:00 committed by Tony Hutter
parent f3421697d0
commit 7d7ae8979a
3 changed files with 55 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
config/kernel-dentry-operations.m4
View File

@ -24,6 +24,9 @@ dnl #
dnl # 2.6.38 API change
dnl # Added d_set_d_op() helper function.
dnl #
dnl # 6.17 API change
dnl # d_set_d_op() removed. No direct replacement.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_SRC_D_SET_D_OP], [
ZFS_LINUX_TEST_SRC([d_set_d_op], [
#include <linux/dcache.h>
@ -34,11 +37,12 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_D_SET_D_OP], [
AC_DEFUN([ZFS_AC_KERNEL_D_SET_D_OP], [
AC_MSG_CHECKING([whether d_set_d_op() is available])
ZFS_LINUX_TEST_RESULT_SYMBOL([d_set_d_op],
[d_set_d_op], [fs/dcache.c], [
ZFS_LINUX_TEST_RESULT([d_set_d_op], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_D_SET_D_OP, 1,
[Define if d_set_d_op() is available])
], [
ZFS_LINUX_TEST_ERROR([d_set_d_op])
AC_MSG_RESULT(no)
])
])

26
include/os/linux/kernel/linux/dcache_compat.h
View File

@ -59,32 +59,6 @@
} 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

55
module/os/linux/zfs/zpl_ctldir.c
View File

@ -197,7 +197,7 @@ zpl_snapdir_revalidate(struct dentry *dentry, unsigned int flags)
return (!!dentry->d_inode);
}
static dentry_operations_t zpl_dops_snapdirs = {
static const struct dentry_operations zpl_dops_snapdirs = {
/*
* Auto mounting of snapshots is only supported for 2.6.37 and
* newer kernels. Prior to this kernel the ops->follow_link()
@ -210,6 +210,51 @@ static dentry_operations_t zpl_dops_snapdirs = {
.d_revalidate = zpl_snapdir_revalidate,
};
/*
* 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 void
set_snapdir_dentry_ops(struct dentry *dentry, unsigned int extraflags) {
static const unsigned int op_flags =
DCACHE_OP_HASH | DCACHE_OP_COMPARE |
DCACHE_OP_REVALIDATE | DCACHE_OP_DELETE |
DCACHE_OP_PRUNE | DCACHE_OP_WEAK_REVALIDATE | DCACHE_OP_REAL;
#ifdef HAVE_D_SET_D_OP
/*
* d_set_d_op() will set the DCACHE_OP_ flags according to what it
* finds in the passed dentry_operations, so we don't have to.
*
* We clear the flags and the old op table before calling d_set_d_op()
* because issues a warning when the dentry operations table is already
* set.
*/
dentry->d_op = NULL;
dentry->d_flags &= ~op_flags;
d_set_d_op(dentry, &zpl_dops_snapdirs);
dentry->d_flags |= extraflags;
#else
/*
* Since 6.17 there's no exported way to modify dentry ops, so we have
* to reach in and do it ourselves. This should be safe for our very
* narrow use case, which is to create or splice in an entry to give
* access to a snapshot.
*
* We need to set the op flags directly. We hardcode
* DCACHE_OP_REVALIDATE because that's the only operation we have; if
* we ever extend zpl_dops_snapdirs we will need to update the op flags
* to match.
*/
spin_lock(&dentry->d_lock);
dentry->d_op = &zpl_dops_snapdirs;
dentry->d_flags &= ~op_flags;
dentry->d_flags |= DCACHE_OP_REVALIDATE | extraflags;
spin_unlock(&dentry->d_lock);
#endif
}
static struct dentry *
zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry,
unsigned int flags)
@ -231,10 +276,7 @@ zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry,
return (ERR_PTR(error));
ASSERT(error == 0 || ip == NULL);
d_clear_d_op(dentry);
d_set_d_op(dentry, &zpl_dops_snapdirs);
dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
set_snapdir_dentry_ops(dentry, DCACHE_NEED_AUTOMOUNT);
return (d_splice_alias(ip, dentry));
}
@ -368,8 +410,7 @@ zpl_snapdir_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode)
error = -zfsctl_snapdir_mkdir(dip, dname(dentry), vap, &ip, cr, 0);
if (error == 0) {
d_clear_d_op(dentry);
d_set_d_op(dentry, &zpl_dops_snapdirs);
set_snapdir_dentry_ops(dentry, 0);
d_instantiate(dentry, ip);
}