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-rw-r--r--fs/kernfs/dir.c100
-rw-r--r--fs/kernfs/file.c4
-rw-r--r--fs/kernfs/inode.c16
-rw-r--r--fs/kernfs/kernfs-internal.h5
-rw-r--r--fs/kernfs/mount.c12
-rw-r--r--fs/kernfs/symlink.c4
6 files changed, 71 insertions, 70 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 0b21a8f961ac..4994723d6cf7 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -17,7 +17,7 @@
#include "kernfs-internal.h"
-DEFINE_MUTEX(kernfs_mutex);
+DECLARE_RWSEM(kernfs_rwsem);
static DEFINE_SPINLOCK(kernfs_rename_lock); /* kn->parent and ->name */
static char kernfs_pr_cont_buf[PATH_MAX]; /* protected by rename_lock */
static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */
@@ -26,7 +26,7 @@ static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */
static bool kernfs_active(struct kernfs_node *kn)
{
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held(&kernfs_rwsem);
return atomic_read(&kn->active) >= 0;
}
@@ -340,7 +340,7 @@ static int kernfs_sd_compare(const struct kernfs_node *left,
* @kn->parent->dir.children.
*
* Locking:
- * mutex_lock(kernfs_mutex)
+ * kernfs_rwsem held exclusive
*
* RETURNS:
* 0 on susccess -EEXIST on failure.
@@ -386,7 +386,7 @@ static int kernfs_link_sibling(struct kernfs_node *kn)
* removed, %false if @kn wasn't on the rbtree.
*
* Locking:
- * mutex_lock(kernfs_mutex)
+ * kernfs_rwsem held exclusive
*/
static bool kernfs_unlink_sibling(struct kernfs_node *kn)
{
@@ -457,14 +457,14 @@ void kernfs_put_active(struct kernfs_node *kn)
* return after draining is complete.
*/
static void kernfs_drain(struct kernfs_node *kn)
- __releases(&kernfs_mutex) __acquires(&kernfs_mutex)
+ __releases(&kernfs_rwsem) __acquires(&kernfs_rwsem)
{
struct kernfs_root *root = kernfs_root(kn);
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_write(&kernfs_rwsem);
WARN_ON_ONCE(kernfs_active(kn));
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
if (kernfs_lockdep(kn)) {
rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
@@ -483,7 +483,7 @@ static void kernfs_drain(struct kernfs_node *kn)
kernfs_drain_open_files(kn);
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
}
/**
@@ -722,7 +722,7 @@ int kernfs_add_one(struct kernfs_node *kn)
bool has_ns;
int ret;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
ret = -EINVAL;
has_ns = kernfs_ns_enabled(parent);
@@ -753,7 +753,7 @@ int kernfs_add_one(struct kernfs_node *kn)
ps_iattr->ia_mtime = ps_iattr->ia_ctime;
}
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
/*
* Activate the new node unless CREATE_DEACTIVATED is requested.
@@ -767,7 +767,7 @@ int kernfs_add_one(struct kernfs_node *kn)
return 0;
out_unlock:
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return ret;
}
@@ -788,7 +788,7 @@ static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent,
bool has_ns = kernfs_ns_enabled(parent);
unsigned int hash;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held(&kernfs_rwsem);
if (has_ns != (bool)ns) {
WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n",
@@ -820,7 +820,7 @@ static struct kernfs_node *kernfs_walk_ns(struct kernfs_node *parent,
size_t len;
char *p, *name;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_read(&kernfs_rwsem);
/* grab kernfs_rename_lock to piggy back on kernfs_pr_cont_buf */
spin_lock_irq(&kernfs_rename_lock);
@@ -860,10 +860,10 @@ struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent,
{
struct kernfs_node *kn;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
kn = kernfs_find_ns(parent, name, ns);
kernfs_get(kn);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return kn;
}
@@ -884,10 +884,10 @@ struct kernfs_node *kernfs_walk_and_get_ns(struct kernfs_node *parent,
{
struct kernfs_node *kn;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
kn = kernfs_walk_ns(parent, path, ns);
kernfs_get(kn);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return kn;
}
@@ -1046,18 +1046,18 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
/* If the kernfs parent node has changed discard and
* proceed to ->lookup.
*/
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
spin_lock(&dentry->d_lock);
parent = kernfs_dentry_node(dentry->d_parent);
if (parent) {
if (kernfs_dir_changed(parent, dentry)) {
spin_unlock(&dentry->d_lock);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return 0;
}
}
spin_unlock(&dentry->d_lock);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
/* The kernfs parent node hasn't changed, leave the
* dentry negative and return success.
@@ -1066,7 +1066,7 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
}
kn = kernfs_dentry_node(dentry);
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
/* The kernfs node has been deactivated */
if (!kernfs_active(kn))
@@ -1085,10 +1085,10 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
kernfs_info(dentry->d_sb)->ns != kn->ns)
goto out_bad;
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return 1;
out_bad:
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return 0;
}
@@ -1106,7 +1106,7 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
struct inode *inode = NULL;
const void *ns = NULL;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
if (kernfs_ns_enabled(parent))
ns = kernfs_info(dir->i_sb)->ns;
@@ -1122,7 +1122,7 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
kernfs_set_rev(parent, dentry);
/* instantiate and hash (possibly negative) dentry */
ret = d_splice_alias(inode, dentry);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return ret;
}
@@ -1244,7 +1244,7 @@ static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos,
{
struct rb_node *rbn;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_write(&kernfs_rwsem);
/* if first iteration, visit leftmost descendant which may be root */
if (!pos)
@@ -1280,7 +1280,7 @@ void kernfs_activate(struct kernfs_node *kn)
{
struct kernfs_node *pos;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
pos = NULL;
while ((pos = kernfs_next_descendant_post(pos, kn))) {
@@ -1294,14 +1294,14 @@ void kernfs_activate(struct kernfs_node *kn)
pos->flags |= KERNFS_ACTIVATED;
}
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
}
static void __kernfs_remove(struct kernfs_node *kn)
{
struct kernfs_node *pos;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_write(&kernfs_rwsem);
/*
* Short-circuit if non-root @kn has already finished removal.
@@ -1324,7 +1324,7 @@ static void __kernfs_remove(struct kernfs_node *kn)
pos = kernfs_leftmost_descendant(kn);
/*
- * kernfs_drain() drops kernfs_mutex temporarily and @pos's
+ * kernfs_drain() drops kernfs_rwsem temporarily and @pos's
* base ref could have been put by someone else by the time
* the function returns. Make sure it doesn't go away
* underneath us.
@@ -1371,9 +1371,9 @@ static void __kernfs_remove(struct kernfs_node *kn)
*/
void kernfs_remove(struct kernfs_node *kn)
{
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
__kernfs_remove(kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
}
/**
@@ -1460,17 +1460,17 @@ bool kernfs_remove_self(struct kernfs_node *kn)
{
bool ret;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
kernfs_break_active_protection(kn);
/*
* SUICIDAL is used to arbitrate among competing invocations. Only
* the first one will actually perform removal. When the removal
* is complete, SUICIDED is set and the active ref is restored
- * while holding kernfs_mutex. The ones which lost arbitration
- * waits for SUICDED && drained which can happen only after the
- * enclosing kernfs operation which executed the winning instance
- * of kernfs_remove_self() finished.
+ * while kernfs_rwsem for held exclusive. The ones which lost
+ * arbitration waits for SUICIDED && drained which can happen only
+ * after the enclosing kernfs operation which executed the winning
+ * instance of kernfs_remove_self() finished.
*/
if (!(kn->flags & KERNFS_SUICIDAL)) {
kn->flags |= KERNFS_SUICIDAL;
@@ -1488,9 +1488,9 @@ bool kernfs_remove_self(struct kernfs_node *kn)
atomic_read(&kn->active) == KN_DEACTIVATED_BIAS)
break;
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
schedule();
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
}
finish_wait(waitq, &wait);
WARN_ON_ONCE(!RB_EMPTY_NODE(&kn->rb));
@@ -1498,12 +1498,12 @@ bool kernfs_remove_self(struct kernfs_node *kn)
}
/*
- * This must be done while holding kernfs_mutex; otherwise, waiting
- * for SUICIDED && deactivated could finish prematurely.
+ * This must be done while kernfs_rwsem held exclusive; otherwise,
+ * waiting for SUICIDED && deactivated could finish prematurely.
*/
kernfs_unbreak_active_protection(kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return ret;
}
@@ -1527,13 +1527,13 @@ int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name,
return -ENOENT;
}
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
kn = kernfs_find_ns(parent, name, ns);
if (kn)
__kernfs_remove(kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
if (kn)
return 0;
@@ -1559,7 +1559,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
if (!kn->parent)
return -EINVAL;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
error = -ENOENT;
if (!kernfs_active(kn) || !kernfs_active(new_parent) ||
@@ -1613,7 +1613,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
error = 0;
out:
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return error;
}
@@ -1688,7 +1688,7 @@ static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx)
if (!dir_emit_dots(file, ctx))
return 0;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
if (kernfs_ns_enabled(parent))
ns = kernfs_info(dentry->d_sb)->ns;
@@ -1705,12 +1705,12 @@ static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx)
file->private_data = pos;
kernfs_get(pos);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
if (!dir_emit(ctx, name, len, ino, type))
return 0;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
}
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
file->private_data = NULL;
ctx->pos = INT_MAX;
return 0;
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index c75719312147..60e2a86c535e 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -860,7 +860,7 @@ repeat:
spin_unlock_irq(&kernfs_notify_lock);
/* kick fsnotify */
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
list_for_each_entry(info, &kernfs_root(kn)->supers, node) {
struct kernfs_node *parent;
@@ -898,7 +898,7 @@ repeat:
iput(inode);
}
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
kernfs_put(kn);
goto repeat;
}
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 26f2aa3586f9..dad749f39518 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -100,9 +100,9 @@ int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
{
int ret;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
ret = __kernfs_setattr(kn, iattr);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return ret;
}
@@ -116,7 +116,7 @@ int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
if (!kn)
return -EINVAL;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
error = setattr_prepare(&init_user_ns, dentry, iattr);
if (error)
goto out;
@@ -129,7 +129,7 @@ int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
setattr_copy(&init_user_ns, inode, iattr);
out:
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return error;
}
@@ -185,9 +185,9 @@ int kernfs_iop_getattr(struct user_namespace *mnt_userns,
struct inode *inode = d_inode(path->dentry);
struct kernfs_node *kn = inode->i_private;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
kernfs_refresh_inode(kn, inode);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
generic_fillattr(&init_user_ns, inode, stat);
return 0;
@@ -278,9 +278,9 @@ int kernfs_iop_permission(struct user_namespace *mnt_userns,
kn = inode->i_private;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
kernfs_refresh_inode(kn, inode);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return generic_permission(&init_user_ns, inode, mask);
}
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index c2ae58f3b202..f9cc912c31e1 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -13,6 +13,7 @@
#include <linux/lockdep.h>
#include <linux/fs.h>
#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/xattr.h>
#include <linux/kernfs.h>
@@ -69,7 +70,7 @@ struct kernfs_super_info {
*/
const void *ns;
- /* anchored at kernfs_root->supers, protected by kernfs_mutex */
+ /* anchored at kernfs_root->supers, protected by kernfs_rwsem */
struct list_head node;
};
#define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
@@ -121,7 +122,7 @@ int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
/*
* dir.c
*/
-extern struct mutex kernfs_mutex;
+extern struct rw_semaphore kernfs_rwsem;
extern const struct dentry_operations kernfs_dops;
extern const struct file_operations kernfs_dir_fops;
extern const struct inode_operations kernfs_dir_iops;
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index 9dc7e7a64e10..baa4155ba2ed 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -255,9 +255,9 @@ static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *k
sb->s_shrink.seeks = 0;
/* get root inode, initialize and unlock it */
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
inode = kernfs_get_inode(sb, info->root->kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
if (!inode) {
pr_debug("kernfs: could not get root inode\n");
return -ENOMEM;
@@ -344,9 +344,9 @@ int kernfs_get_tree(struct fs_context *fc)
}
sb->s_flags |= SB_ACTIVE;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
list_add(&info->node, &info->root->supers);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
}
fc->root = dget(sb->s_root);
@@ -372,9 +372,9 @@ void kernfs_kill_sb(struct super_block *sb)
{
struct kernfs_super_info *info = kernfs_info(sb);
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
list_del(&info->node);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
/*
* Remove the superblock from fs_supers/s_instances
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 5432883d819f..c8f8e41b8411 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -116,9 +116,9 @@ static int kernfs_getlink(struct inode *inode, char *path)
struct kernfs_node *target = kn->symlink.target_kn;
int error;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
error = kernfs_get_target_path(parent, target, path);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return error;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-17 11:21:28 +0000