From 50a212ec906f7524620675f0c57357691c26c81f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 16 Oct 2024 01:20:19 +0000
Subject: [PATCH] 修改GPIO导出默认初始值
---
kernel/fs/kernfs/mount.c | 236 ++++++++++++++++++++++++++--------------------------------
1 files changed, 106 insertions(+), 130 deletions(-)
diff --git a/kernel/fs/kernfs/mount.c b/kernel/fs/kernfs/mount.c
index 0b22c39..9dc7e7a 100644
--- a/kernel/fs/kernfs/mount.c
+++ b/kernel/fs/kernfs/mount.c
@@ -1,11 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* fs/kernfs/mount.c - kernfs mount implementation
*
* Copyright (c) 2001-3 Patrick Mochel
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>
- *
- * This file is released under the GPLv2.
*/
#include <linux/fs.h>
@@ -20,17 +19,7 @@
#include "kernfs-internal.h"
-struct kmem_cache *kernfs_node_cache;
-
-static int kernfs_sop_remount_fs(struct super_block *sb, int *flags, char *data)
-{
- struct kernfs_root *root = kernfs_info(sb)->root;
- struct kernfs_syscall_ops *scops = root->syscall_ops;
-
- if (scops && scops->remount_fs)
- return scops->remount_fs(root, flags, data);
- return 0;
-}
+struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
static int kernfs_sop_show_options(struct seq_file *sf, struct dentry *dentry)
{
@@ -60,68 +49,89 @@
.drop_inode = generic_delete_inode,
.evict_inode = kernfs_evict_inode,
- .remount_fs = kernfs_sop_remount_fs,
.show_options = kernfs_sop_show_options,
.show_path = kernfs_sop_show_path,
};
-/*
- * Similar to kernfs_fh_get_inode, this one gets kernfs node from inode
- * number and generation
- */
-struct kernfs_node *kernfs_get_node_by_id(struct kernfs_root *root,
- const union kernfs_node_id *id)
+static int kernfs_encode_fh(struct inode *inode, __u32 *fh, int *max_len,
+ struct inode *parent)
{
- struct kernfs_node *kn;
+ struct kernfs_node *kn = inode->i_private;
- kn = kernfs_find_and_get_node_by_ino(root, id->ino);
- if (!kn)
- return NULL;
- if (kn->id.generation != id->generation) {
- kernfs_put(kn);
- return NULL;
+ if (*max_len < 2) {
+ *max_len = 2;
+ return FILEID_INVALID;
}
- return kn;
+
+ *max_len = 2;
+ *(u64 *)fh = kn->id;
+ return FILEID_KERNFS;
}
-static struct inode *kernfs_fh_get_inode(struct super_block *sb,
- u64 ino, u32 generation)
+static struct dentry *__kernfs_fh_to_dentry(struct super_block *sb,
+ struct fid *fid, int fh_len,
+ int fh_type, bool get_parent)
{
struct kernfs_super_info *info = kernfs_info(sb);
- struct inode *inode;
struct kernfs_node *kn;
+ struct inode *inode;
+ u64 id;
- if (ino == 0)
- return ERR_PTR(-ESTALE);
+ if (fh_len < 2)
+ return NULL;
- kn = kernfs_find_and_get_node_by_ino(info->root, ino);
+ switch (fh_type) {
+ case FILEID_KERNFS:
+ id = *(u64 *)fid;
+ break;
+ case FILEID_INO32_GEN:
+ case FILEID_INO32_GEN_PARENT:
+ /*
+ * blk_log_action() exposes "LOW32,HIGH32" pair without
+ * type and userland can call us with generic fid
+ * constructed from them. Combine it back to ID. See
+ * blk_log_action().
+ */
+ id = ((u64)fid->i32.gen << 32) | fid->i32.ino;
+ break;
+ default:
+ return NULL;
+ }
+
+ kn = kernfs_find_and_get_node_by_id(info->root, id);
if (!kn)
return ERR_PTR(-ESTALE);
+
+ if (get_parent) {
+ struct kernfs_node *parent;
+
+ parent = kernfs_get_parent(kn);
+ kernfs_put(kn);
+ kn = parent;
+ if (!kn)
+ return ERR_PTR(-ESTALE);
+ }
+
inode = kernfs_get_inode(sb, kn);
kernfs_put(kn);
if (!inode)
return ERR_PTR(-ESTALE);
- if (generation && inode->i_generation != generation) {
- /* we didn't find the right inode.. */
- iput(inode);
- return ERR_PTR(-ESTALE);
- }
- return inode;
+ return d_obtain_alias(inode);
}
-static struct dentry *kernfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
- int fh_len, int fh_type)
+static struct dentry *kernfs_fh_to_dentry(struct super_block *sb,
+ struct fid *fid, int fh_len,
+ int fh_type)
{
- return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
- kernfs_fh_get_inode);
+ return __kernfs_fh_to_dentry(sb, fid, fh_len, fh_type, false);
}
-static struct dentry *kernfs_fh_to_parent(struct super_block *sb, struct fid *fid,
- int fh_len, int fh_type)
+static struct dentry *kernfs_fh_to_parent(struct super_block *sb,
+ struct fid *fid, int fh_len,
+ int fh_type)
{
- return generic_fh_to_parent(sb, fid, fh_len, fh_type,
- kernfs_fh_get_inode);
+ return __kernfs_fh_to_dentry(sb, fid, fh_len, fh_type, true);
}
static struct dentry *kernfs_get_parent_dentry(struct dentry *child)
@@ -132,6 +142,7 @@
}
static const struct export_operations kernfs_export_ops = {
+ .encode_fh = kernfs_encode_fh,
.fh_to_dentry = kernfs_fh_to_dentry,
.fh_to_parent = kernfs_fh_to_parent,
.get_parent = kernfs_get_parent_dentry,
@@ -212,7 +223,7 @@
dput(dentry);
return ERR_PTR(-EINVAL);
}
- dtmp = lookup_one_len_unlocked(kntmp->name, dentry,
+ dtmp = lookup_positive_unlocked(kntmp->name, dentry,
strlen(kntmp->name));
dput(dentry);
if (IS_ERR(dtmp))
@@ -222,7 +233,7 @@
} while (true);
}
-static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
+static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *kfc)
{
struct kernfs_super_info *info = kernfs_info(sb);
struct inode *inode;
@@ -233,12 +244,15 @@
sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
- sb->s_magic = magic;
+ sb->s_magic = kfc->magic;
sb->s_op = &kernfs_sops;
sb->s_xattr = kernfs_xattr_handlers;
if (info->root->flags & KERNFS_ROOT_SUPPORT_EXPORTOP)
sb->s_export_op = &kernfs_export_ops;
sb->s_time_gran = 1;
+
+ /* sysfs dentries and inodes don't require IO to create */
+ sb->s_shrink.seeks = 0;
/* get root inode, initialize and unlock it */
mutex_lock(&kernfs_mutex);
@@ -260,21 +274,20 @@
return 0;
}
-static int kernfs_test_super(struct super_block *sb, void *data)
+static int kernfs_test_super(struct super_block *sb, struct fs_context *fc)
{
struct kernfs_super_info *sb_info = kernfs_info(sb);
- struct kernfs_super_info *info = data;
+ struct kernfs_super_info *info = fc->s_fs_info;
return sb_info->root == info->root && sb_info->ns == info->ns;
}
-static int kernfs_set_super(struct super_block *sb, void *data)
+static int kernfs_set_super(struct super_block *sb, struct fs_context *fc)
{
- int error;
- error = set_anon_super(sb, data);
- if (!error)
- sb->s_fs_info = data;
- return error;
+ struct kernfs_fs_context *kfc = fc->fs_private;
+
+ kfc->ns_tag = NULL;
+ return set_anon_super_fc(sb, fc);
}
/**
@@ -291,63 +304,60 @@
}
/**
- * kernfs_mount_ns - kernfs mount helper
- * @fs_type: file_system_type of the fs being mounted
- * @flags: mount flags specified for the mount
- * @root: kernfs_root of the hierarchy being mounted
- * @magic: file system specific magic number
- * @new_sb_created: tell the caller if we allocated a new superblock
- * @ns: optional namespace tag of the mount
+ * kernfs_get_tree - kernfs filesystem access/retrieval helper
+ * @fc: The filesystem context.
*
- * This is to be called from each kernfs user's file_system_type->mount()
- * implementation, which should pass through the specified @fs_type and
- * @flags, and specify the hierarchy and namespace tag to mount via @root
- * and @ns, respectively.
- *
- * The return value can be passed to the vfs layer verbatim.
+ * This is to be called from each kernfs user's fs_context->ops->get_tree()
+ * implementation, which should set the specified ->@fs_type and ->@flags, and
+ * specify the hierarchy and namespace tag to mount via ->@root and ->@ns,
+ * respectively.
*/
-struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
- struct kernfs_root *root, unsigned long magic,
- bool *new_sb_created, const void *ns)
+int kernfs_get_tree(struct fs_context *fc)
{
+ struct kernfs_fs_context *kfc = fc->fs_private;
struct super_block *sb;
struct kernfs_super_info *info;
int error;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
- return ERR_PTR(-ENOMEM);
+ return -ENOMEM;
- info->root = root;
- info->ns = ns;
+ info->root = kfc->root;
+ info->ns = kfc->ns_tag;
INIT_LIST_HEAD(&info->node);
- sb = sget_userns(fs_type, kernfs_test_super, kernfs_set_super, flags,
- &init_user_ns, info);
- if (IS_ERR(sb) || sb->s_fs_info != info)
- kfree(info);
+ fc->s_fs_info = info;
+ sb = sget_fc(fc, kernfs_test_super, kernfs_set_super);
if (IS_ERR(sb))
- return ERR_CAST(sb);
-
- if (new_sb_created)
- *new_sb_created = !sb->s_root;
+ return PTR_ERR(sb);
if (!sb->s_root) {
struct kernfs_super_info *info = kernfs_info(sb);
- error = kernfs_fill_super(sb, magic);
+ kfc->new_sb_created = true;
+
+ error = kernfs_fill_super(sb, kfc);
if (error) {
deactivate_locked_super(sb);
- return ERR_PTR(error);
+ return error;
}
sb->s_flags |= SB_ACTIVE;
mutex_lock(&kernfs_mutex);
- list_add(&info->node, &root->supers);
+ list_add(&info->node, &info->root->supers);
mutex_unlock(&kernfs_mutex);
}
- return dget(sb->s_root);
+ fc->root = dget(sb->s_root);
+ return 0;
+}
+
+void kernfs_free_fs_context(struct fs_context *fc)
+{
+ /* Note that we don't deal with kfc->ns_tag here. */
+ kfree(fc->s_fs_info);
+ fc->s_fs_info = NULL;
}
/**
@@ -374,48 +384,14 @@
kfree(info);
}
-/**
- * kernfs_pin_sb: try to pin the superblock associated with a kernfs_root
- * @kernfs_root: the kernfs_root in question
- * @ns: the namespace tag
- *
- * Pin the superblock so the superblock won't be destroyed in subsequent
- * operations. This can be used to block ->kill_sb() which may be useful
- * for kernfs users which dynamically manage superblocks.
- *
- * Returns NULL if there's no superblock associated to this kernfs_root, or
- * -EINVAL if the superblock is being freed.
- */
-struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns)
-{
- struct kernfs_super_info *info;
- struct super_block *sb = NULL;
-
- mutex_lock(&kernfs_mutex);
- list_for_each_entry(info, &root->supers, node) {
- if (info->ns == ns) {
- sb = info->sb;
- if (!atomic_inc_not_zero(&info->sb->s_active))
- sb = ERR_PTR(-EINVAL);
- break;
- }
- }
- mutex_unlock(&kernfs_mutex);
- return sb;
-}
-
void __init kernfs_init(void)
{
-
- /*
- * the slab is freed in RCU context, so kernfs_find_and_get_node_by_ino
- * can access the slab lock free. This could introduce stale nodes,
- * please see how kernfs_find_and_get_node_by_ino filters out stale
- * nodes.
- */
kernfs_node_cache = kmem_cache_create("kernfs_node_cache",
sizeof(struct kernfs_node),
- 0,
- SLAB_PANIC | SLAB_TYPESAFE_BY_RCU,
- NULL);
+ 0, SLAB_PANIC, NULL);
+
+ /* Creates slab cache for kernfs inode attributes */
+ kernfs_iattrs_cache = kmem_cache_create("kernfs_iattrs_cache",
+ sizeof(struct kernfs_iattrs),
+ 0, SLAB_PANIC, NULL);
}
--
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