Remove vn_set_fs_pwd()/vn_set_pwd() (no need to be at / during insmod)

Per suggestion from @behlendorf in #8777, remove vn_set_fs_pwd() and
vn_set_pwd() which are only used in zfs_ioctl.c:_init() while loading
zfs.ko.

The rest of initialization functions being called here after cwd set
to / don't depend on cwd of the process except for spa_config_load().
spa_config_load() uses a relative path ".//etc/zfs/zpool.cache" when
`rootdir` is non-NULL, which is "/etc/zfs/zpool.cache" given cwd is /,
so just unconditionally use the absolute path without "./", so that
`vn_set_pwd("/")` as well as the entire functions can be removed.
This is also what FreeBSD does.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@osnexus.com>
Closes #8826
This commit is contained in:
Tomohiro Kusumi 2019-05-30 08:18:14 +09:00 committed by Brian Behlendorf
parent 1e724f4f34
commit fe0c9f409a
6 changed files with 1 additions and 93 deletions

View File

@ -1,24 +0,0 @@
dnl #
dnl # 2.6.36 API change,
dnl # The 'struct fs_struct->lock' was changed from a rwlock_t to
dnl # a spinlock_t to improve the fastpath performance.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_FS_STRUCT_SPINLOCK], [
AC_MSG_CHECKING([whether struct fs_struct uses spinlock_t])
tmp_flags="$EXTRA_KCFLAGS"
EXTRA_KCFLAGS="-Werror"
ZFS_LINUX_TRY_COMPILE([
#include <linux/sched.h>
#include <linux/fs_struct.h>
],[
static struct fs_struct fs;
spin_lock_init(&fs.lock);
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_FS_STRUCT_SPINLOCK, 1,
[struct fs_struct uses spinlock_t])
],[
AC_MSG_RESULT(no)
])
EXTRA_KCFLAGS="$tmp_flags"
])

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@ -12,7 +12,6 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
ZFS_AC_KERNEL_CTL_NAME
ZFS_AC_KERNEL_PDE_DATA
ZFS_AC_KERNEL_2ARGS_VFS_FSYNC
ZFS_AC_KERNEL_FS_STRUCT_SPINLOCK
ZFS_AC_KERNEL_KUIDGID_T
ZFS_AC_KERNEL_FALLOCATE
ZFS_AC_KERNEL_2ARGS_ZLIB_DEFLATE_WORKSPACESIZE

View File

@ -182,7 +182,6 @@ extern int vn_space(vnode_t *vp, int cmd, struct flock *bfp, int flag,
extern file_t *vn_getf(int fd);
extern void vn_releasef(int fd);
extern void vn_areleasef(int fd, uf_info_t *fip);
extern int vn_set_pwd(const char *filename);
int spl_vn_init(void);
void spl_vn_fini(void);

View File

@ -641,64 +641,6 @@ vn_areleasef(int fd, uf_info_t *fip)
} /* releasef() */
EXPORT_SYMBOL(areleasef);
static void
vn_set_fs_pwd(struct fs_struct *fs, struct path *path)
{
struct path old_pwd;
#ifdef HAVE_FS_STRUCT_SPINLOCK
spin_lock(&fs->lock);
old_pwd = fs->pwd;
fs->pwd = *path;
path_get(path);
spin_unlock(&fs->lock);
#else
write_lock(&fs->lock);
old_pwd = fs->pwd;
fs->pwd = *path;
path_get(path);
write_unlock(&fs->lock);
#endif /* HAVE_FS_STRUCT_SPINLOCK */
if (old_pwd.dentry)
path_put(&old_pwd);
}
int
vn_set_pwd(const char *filename)
{
struct path path;
mm_segment_t saved_fs;
int rc;
/*
* user_path_dir() and __user_walk() both expect 'filename' to be
* a user space address so we must briefly increase the data segment
* size to ensure strncpy_from_user() does not fail with -EFAULT.
*/
saved_fs = get_fs();
set_fs(KERNEL_DS);
rc = user_path_dir(filename, &path);
if (rc)
goto out;
rc = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
if (rc)
goto dput_and_out;
vn_set_fs_pwd(current->fs, &path);
dput_and_out:
path_put(&path);
out:
set_fs(saved_fs);
return (-rc);
} /* vn_set_pwd() */
EXPORT_SYMBOL(vn_set_pwd);
static int
vn_cache_constructor(void *buf, void *cdrarg, int kmflags)
{

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@ -93,8 +93,7 @@ spa_config_load(void)
*/
pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
(void) snprintf(pathname, MAXPATHLEN, "%s%s",
(rootdir != NULL) ? "./" : "", spa_config_path);
(void) snprintf(pathname, MAXPATHLEN, "%s", spa_config_path);
file = kobj_open_file(pathname);

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@ -7380,13 +7380,6 @@ _init(void)
{
int error;
error = -vn_set_pwd("/");
if (error) {
printk(KERN_NOTICE
"ZFS: Warning unable to set pwd to '/': %d\n", error);
return (error);
}
if ((error = -zvol_init()) != 0)
return (error);