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-rw-r--r--drivers/base/arch_topology.c2
-rw-r--r--drivers/base/core.c2
-rw-r--r--drivers/base/dd.c16
-rw-r--r--drivers/base/test/test_async_driver_probe.c6
-rw-r--r--drivers/infiniband/hw/hfi1/debugfs.c20
-rw-r--r--fs/debugfs/file.c216
-rw-r--r--fs/debugfs/inode.c62
-rw-r--r--fs/debugfs/internal.h20
-rw-r--r--include/linux/debugfs.h38
-rw-r--r--lib/Kconfig.debug1
10 files changed, 217 insertions, 166 deletions
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 0739c5b953bf..4de87b0b53c8 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -105,7 +105,7 @@ subsys_initcall(register_cpu_capacity_sysctl);
static u32 capacity_scale;
static u32 *raw_capacity;
-static int __init free_raw_capacity(void)
+static int free_raw_capacity(void)
{
kfree(raw_capacity);
raw_capacity = NULL;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index a36cf1bd07a9..110230d86527 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1958,7 +1958,6 @@ void device_del(struct device *dev)
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
- device_links_purge(dev);
dpm_sysfs_remove(dev);
if (parent)
klist_del(&dev->p->knode_parent);
@@ -1986,6 +1985,7 @@ void device_del(struct device *dev)
device_pm_remove(dev);
driver_deferred_probe_del(dev);
device_remove_properties(dev);
+ device_links_purge(dev);
/* Notify the platform of the removal, in case they
* need to do anything...
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 45575e134696..2c964f56dafe 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -350,6 +350,15 @@ EXPORT_SYMBOL_GPL(device_bind_driver);
static atomic_t probe_count = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
+static void driver_deferred_probe_add_trigger(struct device *dev,
+ int local_trigger_count)
+{
+ driver_deferred_probe_add(dev);
+ /* Did a trigger occur while probing? Need to re-trigger if yes */
+ if (local_trigger_count != atomic_read(&deferred_trigger_count))
+ driver_deferred_probe_trigger();
+}
+
static int really_probe(struct device *dev, struct device_driver *drv)
{
int ret = -EPROBE_DEFER;
@@ -369,6 +378,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
}
ret = device_links_check_suppliers(dev);
+ if (ret == -EPROBE_DEFER)
+ driver_deferred_probe_add_trigger(dev, local_trigger_count);
if (ret)
return ret;
@@ -470,10 +481,7 @@ pinctrl_bind_failed:
case -EPROBE_DEFER:
/* Driver requested deferred probing */
dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
- driver_deferred_probe_add(dev);
- /* Did a trigger occur while probing? Need to re-trigger if yes */
- if (local_trigger_count != atomic_read(&deferred_trigger_count))
- driver_deferred_probe_trigger();
+ driver_deferred_probe_add_trigger(dev, local_trigger_count);
break;
case -ENODEV:
case -ENXIO:
diff --git a/drivers/base/test/test_async_driver_probe.c b/drivers/base/test/test_async_driver_probe.c
index 304d5c2bd5e9..a3355d66bc12 100644
--- a/drivers/base/test/test_async_driver_probe.c
+++ b/drivers/base/test/test_async_driver_probe.c
@@ -64,7 +64,7 @@ static int __init test_async_probe_init(void)
NULL, 0);
if (IS_ERR(async_dev_1)) {
error = PTR_ERR(async_dev_1);
- pr_err("failed to create async_dev_1: %d", error);
+ pr_err("failed to create async_dev_1: %d\n", error);
return error;
}
@@ -91,7 +91,7 @@ static int __init test_async_probe_init(void)
NULL, 0);
if (IS_ERR(async_dev_2)) {
error = PTR_ERR(async_dev_2);
- pr_err("failed to create async_dev_2: %d", error);
+ pr_err("failed to create async_dev_2: %d\n", error);
goto err_unregister_async_driver;
}
@@ -118,7 +118,7 @@ static int __init test_async_probe_init(void)
NULL, 0);
if (IS_ERR(sync_dev_1)) {
error = PTR_ERR(sync_dev_1);
- pr_err("failed to create sync_dev_1: %d", error);
+ pr_err("failed to create sync_dev_1: %d\n", error);
goto err_unregister_sync_driver;
}
diff --git a/drivers/infiniband/hw/hfi1/debugfs.c b/drivers/infiniband/hw/hfi1/debugfs.c
index 76157cc03eca..2e6e0c516041 100644
--- a/drivers/infiniband/hw/hfi1/debugfs.c
+++ b/drivers/infiniband/hw/hfi1/debugfs.c
@@ -71,13 +71,13 @@ static ssize_t hfi1_seq_read(
loff_t *ppos)
{
struct dentry *d = file->f_path.dentry;
- int srcu_idx;
ssize_t r;
- r = debugfs_use_file_start(d, &srcu_idx);
- if (likely(!r))
- r = seq_read(file, buf, size, ppos);
- debugfs_use_file_finish(srcu_idx);
+ r = debugfs_file_get(d);
+ if (unlikely(r))
+ return r;
+ r = seq_read(file, buf, size, ppos);
+ debugfs_file_put(d);
return r;
}
@@ -87,13 +87,13 @@ static loff_t hfi1_seq_lseek(
int whence)
{
struct dentry *d = file->f_path.dentry;
- int srcu_idx;
loff_t r;
- r = debugfs_use_file_start(d, &srcu_idx);
- if (likely(!r))
- r = seq_lseek(file, offset, whence);
- debugfs_use_file_finish(srcu_idx);
+ r = debugfs_file_get(d);
+ if (unlikely(r))
+ return r;
+ r = seq_lseek(file, offset, whence);
+ debugfs_file_put(d);
return r;
}
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 6dabc4a10396..cd12e6576b48 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -1,16 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* file.c - part of debugfs, a tiny little debug file system
*
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
* debugfs is for people to use instead of /proc or /sys.
* See Documentation/filesystems/ for more details.
- *
*/
#include <linux/module.h>
@@ -22,7 +18,6 @@
#include <linux/slab.h>
#include <linux/atomic.h>
#include <linux/device.h>
-#include <linux/srcu.h>
#include <asm/poll.h>
#include "internal.h"
@@ -48,66 +43,108 @@ const struct file_operations debugfs_noop_file_operations = {
.llseek = noop_llseek,
};
+#define F_DENTRY(filp) ((filp)->f_path.dentry)
+
+const struct file_operations *debugfs_real_fops(const struct file *filp)
+{
+ struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata;
+
+ if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) {
+ /*
+ * Urgh, we've been called w/o a protecting
+ * debugfs_file_get().
+ */
+ WARN_ON(1);
+ return NULL;
+ }
+
+ return fsd->real_fops;
+}
+EXPORT_SYMBOL_GPL(debugfs_real_fops);
+
/**
- * debugfs_use_file_start - mark the beginning of file data access
+ * debugfs_file_get - mark the beginning of file data access
* @dentry: the dentry object whose data is being accessed.
- * @srcu_idx: a pointer to some memory to store a SRCU index in.
*
- * Up to a matching call to debugfs_use_file_finish(), any
- * successive call into the file removing functions debugfs_remove()
- * and debugfs_remove_recursive() will block. Since associated private
+ * Up to a matching call to debugfs_file_put(), any successive call
+ * into the file removing functions debugfs_remove() and
+ * debugfs_remove_recursive() will block. Since associated private
* file data may only get freed after a successful return of any of
* the removal functions, you may safely access it after a successful
- * call to debugfs_use_file_start() without worrying about
- * lifetime issues.
+ * call to debugfs_file_get() without worrying about lifetime issues.
*
* If -%EIO is returned, the file has already been removed and thus,
* it is not safe to access any of its data. If, on the other hand,
* it is allowed to access the file data, zero is returned.
- *
- * Regardless of the return code, any call to
- * debugfs_use_file_start() must be followed by a matching call
- * to debugfs_use_file_finish().
*/
-int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx)
- __acquires(&debugfs_srcu)
+int debugfs_file_get(struct dentry *dentry)
{
- *srcu_idx = srcu_read_lock(&debugfs_srcu);
- barrier();
+ struct debugfs_fsdata *fsd;
+ void *d_fsd;
+
+ d_fsd = READ_ONCE(dentry->d_fsdata);
+ if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
+ fsd = d_fsd;
+ } else {
+ fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
+ if (!fsd)
+ return -ENOMEM;
+
+ fsd->real_fops = (void *)((unsigned long)d_fsd &
+ ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
+ refcount_set(&fsd->active_users, 1);
+ init_completion(&fsd->active_users_drained);
+ if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) {
+ kfree(fsd);
+ fsd = READ_ONCE(dentry->d_fsdata);
+ }
+ }
+
+ /*
+ * In case of a successful cmpxchg() above, this check is
+ * strictly necessary and must follow it, see the comment in
+ * __debugfs_remove_file().
+ * OTOH, if the cmpxchg() hasn't been executed or wasn't
+ * successful, this serves the purpose of not starving
+ * removers.
+ */
if (d_unlinked(dentry))
return -EIO;
+
+ if (!refcount_inc_not_zero(&fsd->active_users))
+ return -EIO;
+
return 0;
}
-EXPORT_SYMBOL_GPL(debugfs_use_file_start);
+EXPORT_SYMBOL_GPL(debugfs_file_get);
/**
- * debugfs_use_file_finish - mark the end of file data access
- * @srcu_idx: the SRCU index "created" by a former call to
- * debugfs_use_file_start().
+ * debugfs_file_put - mark the end of file data access
+ * @dentry: the dentry object formerly passed to
+ * debugfs_file_get().
*
* Allow any ongoing concurrent call into debugfs_remove() or
* debugfs_remove_recursive() blocked by a former call to
- * debugfs_use_file_start() to proceed and return to its caller.
+ * debugfs_file_get() to proceed and return to its caller.
*/
-void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu)
+void debugfs_file_put(struct dentry *dentry)
{
- srcu_read_unlock(&debugfs_srcu, srcu_idx);
-}
-EXPORT_SYMBOL_GPL(debugfs_use_file_finish);
+ struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata);
-#define F_DENTRY(filp) ((filp)->f_path.dentry)
+ if (refcount_dec_and_test(&fsd->active_users))
+ complete(&fsd->active_users_drained);
+}
+EXPORT_SYMBOL_GPL(debugfs_file_put);
static int open_proxy_open(struct inode *inode, struct file *filp)
{
- const struct dentry *dentry = F_DENTRY(filp);
+ struct dentry *dentry = F_DENTRY(filp);
const struct file_operations *real_fops = NULL;
- int srcu_idx, r;
+ int r;
- r = debugfs_use_file_start(dentry, &srcu_idx);
- if (r) {
- r = -ENOENT;
- goto out;
- }
+ r = debugfs_file_get(dentry);
+ if (r)
+ return r == -EIO ? -ENOENT : r;
real_fops = debugfs_real_fops(filp);
real_fops = fops_get(real_fops);
@@ -124,7 +161,7 @@ static int open_proxy_open(struct inode *inode, struct file *filp)
r = real_fops->open(inode, filp);
out:
- debugfs_use_file_finish(srcu_idx);
+ debugfs_file_put(dentry);
return r;
}
@@ -138,16 +175,16 @@ const struct file_operations debugfs_open_proxy_file_operations = {
#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \
static ret_type full_proxy_ ## name(proto) \
{ \
- const struct dentry *dentry = F_DENTRY(filp); \
- const struct file_operations *real_fops = \
- debugfs_real_fops(filp); \
- int srcu_idx; \
+ struct dentry *dentry = F_DENTRY(filp); \
+ const struct file_operations *real_fops; \
ret_type r; \
\
- r = debugfs_use_file_start(dentry, &srcu_idx); \
- if (likely(!r)) \
- r = real_fops->name(args); \
- debugfs_use_file_finish(srcu_idx); \
+ r = debugfs_file_get(dentry); \
+ if (unlikely(r)) \
+ return r; \
+ real_fops = debugfs_real_fops(filp); \
+ r = real_fops->name(args); \
+ debugfs_file_put(dentry); \
return r; \
}
@@ -172,18 +209,16 @@ FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
static unsigned int full_proxy_poll(struct file *filp,
struct poll_table_struct *wait)
{
- const struct dentry *dentry = F_DENTRY(filp);
- const struct file_operations *real_fops = debugfs_real_fops(filp);
- int srcu_idx;
+ struct dentry *dentry = F_DENTRY(filp);
unsigned int r = 0;
+ const struct file_operations *real_fops;
- if (debugfs_use_file_start(dentry, &srcu_idx)) {
- debugfs_use_file_finish(srcu_idx);
+ if (debugfs_file_get(dentry))
return POLLHUP;
- }
+ real_fops = debugfs_real_fops(filp);
r = real_fops->poll(filp, wait);
- debugfs_use_file_finish(srcu_idx);
+ debugfs_file_put(dentry);
return r;
}
@@ -227,16 +262,14 @@ static void __full_proxy_fops_init(struct file_operations *proxy_fops,
static int full_proxy_open(struct inode *inode, struct file *filp)
{
- const struct dentry *dentry = F_DENTRY(filp);
+ struct dentry *dentry = F_DENTRY(filp);
const struct file_operations *real_fops = NULL;
struct file_operations *proxy_fops = NULL;
- int srcu_idx, r;
+ int r;
- r = debugfs_use_file_start(dentry, &srcu_idx);
- if (r) {
- r = -ENOENT;
- goto out;
- }
+ r = debugfs_file_get(dentry);
+ if (r)
+ return r == -EIO ? -ENOENT : r;
real_fops = debugfs_real_fops(filp);
real_fops = fops_get(real_fops);
@@ -274,7 +307,7 @@ free_proxy:
kfree(proxy_fops);
fops_put(real_fops);
out:
- debugfs_use_file_finish(srcu_idx);
+ debugfs_file_put(dentry);
return r;
}
@@ -285,13 +318,14 @@ const struct file_operations debugfs_full_proxy_file_operations = {
ssize_t debugfs_attr_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos)
{
+ struct dentry *dentry = F_DENTRY(file);
ssize_t ret;
- int srcu_idx;
- ret = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
- if (likely(!ret))
- ret = simple_attr_read(file, buf, len, ppos);
- debugfs_use_file_finish(srcu_idx);
+ ret = debugfs_file_get(dentry);
+ if (unlikely(ret))
+ return ret;
+ ret = simple_attr_read(file, buf, len, ppos);
+ debugfs_file_put(dentry);
return ret;
}
EXPORT_SYMBOL_GPL(debugfs_attr_read);
@@ -299,13 +333,14 @@ EXPORT_SYMBOL_GPL(debugfs_attr_read);
ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
+ struct dentry *dentry = F_DENTRY(file);
ssize_t ret;
- int srcu_idx;
- ret = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
- if (likely(!ret))
- ret = simple_attr_write(file, buf, len, ppos);
- debugfs_use_file_finish(srcu_idx);
+ ret = debugfs_file_get(dentry);
+ if (unlikely(ret))
+ return ret;
+ ret = simple_attr_write(file, buf, len, ppos);
+ debugfs_file_put(dentry);
return ret;
}
EXPORT_SYMBOL_GPL(debugfs_attr_write);
@@ -739,14 +774,14 @@ ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
{
char buf[3];
bool val;
- int r, srcu_idx;
+ int r;
+ struct dentry *dentry = F_DENTRY(file);
- r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
- if (likely(!r))
- val = *(bool *)file->private_data;
- debugfs_use_file_finish(srcu_idx);
- if (r)
+ r = debugfs_file_get(dentry);
+ if (unlikely(r))
return r;
+ val = *(bool *)file->private_data;
+ debugfs_file_put(dentry);
if (val)
buf[0] = 'Y';
@@ -764,8 +799,9 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
char buf[32];
size_t buf_size;
bool bv;
- int r, srcu_idx;
+ int r;
bool *val = file->private_data;
+ struct dentry *dentry = F_DENTRY(file);
buf_size = min(count, (sizeof(buf)-1));
if (copy_from_user(buf, user_buf, buf_size))
@@ -773,12 +809,11 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
buf[buf_size] = '\0';
if (strtobool(buf, &bv) == 0) {
- r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
- if (likely(!r))
- *val = bv;
- debugfs_use_file_finish(srcu_idx);
- if (r)
+ r = debugfs_file_get(dentry);
+ if (unlikely(r))
return r;
+ *val = bv;
+ debugfs_file_put(dentry);
}
return count;
@@ -840,14 +875,15 @@ static ssize_t read_file_blob(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct debugfs_blob_wrapper *blob = file->private_data;
+ struct dentry *dentry = F_DENTRY(file);
ssize_t r;
- int srcu_idx;
- r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
- if (likely(!r))
- r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
- blob->size);
- debugfs_use_file_finish(srcu_idx);
+ r = debugfs_file_get(dentry);
+ if (unlikely(r))
+ return r;
+ r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
+ blob->size);
+ debugfs_file_put(dentry);
return r;
}
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index c59f015f386e..63a998c3f252 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -1,16 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* inode.c - part of debugfs, a tiny little debug file system
*
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
* debugfs is for people to use instead of /proc or /sys.
* See ./Documentation/core-api/kernel-api.rst for more details.
- *
*/
#include <linux/module.h>
@@ -27,14 +23,11 @@
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/slab.h>
-#include <linux/srcu.h>
#include "internal.h"
#define DEBUGFS_DEFAULT_MODE 0700
-DEFINE_SRCU(debugfs_srcu);
-
static struct vfsmount *debugfs_mount;
static int debugfs_mount_count;
static bool debugfs_registered;
@@ -185,6 +178,14 @@ static const struct super_operations debugfs_super_operations = {
.evict_inode = debugfs_evict_inode,
};
+static void debugfs_release_dentry(struct dentry *dentry)
+{
+ void *fsd = dentry->d_fsdata;
+
+ if (!((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))
+ kfree(dentry->d_fsdata);
+}
+
static struct vfsmount *debugfs_automount(struct path *path)
{
debugfs_automount_t f;
@@ -194,6 +195,7 @@ static struct vfsmount *debugfs_automount(struct path *path)
static const struct dentry_operations debugfs_dops = {
.d_delete = always_delete_dentry,
+ .d_release = debugfs_release_dentry,
.d_automount = debugfs_automount,
};
@@ -358,7 +360,8 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
inode->i_private = data;
inode->i_fop = proxy_fops;
- dentry->d_fsdata = (void *)real_fops;
+ dentry->d_fsdata = (void *)((unsigned long)real_fops |
+ DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
d_instantiate(dentry, inode);
fsnotify_create(d_inode(dentry->d_parent), dentry);
@@ -615,18 +618,43 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
}
EXPORT_SYMBOL_GPL(debugfs_create_symlink);
+static void __debugfs_remove_file(struct dentry *dentry, struct dentry *parent)
+{
+ struct debugfs_fsdata *fsd;
+
+ simple_unlink(d_inode(parent), dentry);
+ d_delete(dentry);
+
+ /*
+ * Paired with the closing smp_mb() implied by a successful
+ * cmpxchg() in debugfs_file_get(): either
+ * debugfs_file_get() must see a dead dentry or we must see a
+ * debugfs_fsdata instance at ->d_fsdata here (or both).
+ */
+ smp_mb();
+ fsd = READ_ONCE(dentry->d_fsdata);
+ if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)
+ return;
+ if (!refcount_dec_and_test(&fsd->active_users))
+ wait_for_completion(&fsd->active_users_drained);
+}
+
static int __debugfs_remove(struct dentry *dentry, struct dentry *parent)
{
int ret = 0;
if (simple_positive(dentry)) {
dget(dentry);
- if (d_is_dir(dentry))
- ret = simple_rmdir(d_inode(parent), dentry);
- else
- simple_unlink(d_inode(parent), dentry);
- if (!ret)
- d_delete(dentry);
+ if (!d_is_reg(dentry)) {
+ if (d_is_dir(dentry))
+ ret = simple_rmdir(d_inode(parent), dentry);
+ else
+ simple_unlink(d_inode(parent), dentry);
+ if (!ret)
+ d_delete(dentry);
+ } else {
+ __debugfs_remove_file(dentry, parent);
+ }
dput(dentry);
}
return ret;
@@ -660,8 +688,6 @@ void debugfs_remove(struct dentry *dentry)
inode_unlock(d_inode(parent));
if (!ret)
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
-
- synchronize_srcu(&debugfs_srcu);
}
EXPORT_SYMBOL_GPL(debugfs_remove);
@@ -735,8 +761,6 @@ void debugfs_remove_recursive(struct dentry *dentry)
if (!__debugfs_remove(child, parent))
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
inode_unlock(d_inode(parent));
-
- synchronize_srcu(&debugfs_srcu);
}
EXPORT_SYMBOL_GPL(debugfs_remove_recursive);
diff --git a/fs/debugfs/internal.h b/fs/debugfs/internal.h
index b3e8443a1f47..f0d73d86cc1a 100644
--- a/fs/debugfs/internal.h
+++ b/fs/debugfs/internal.h
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* internal.h - declarations internal to debugfs
*
* Copyright (C) 2016 Nicolai Stange <nicstange@gmail.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
*/
#ifndef _DEBUGFS_INTERNAL_H_
@@ -19,4 +15,18 @@ extern const struct file_operations debugfs_noop_file_operations;
extern const struct file_operations debugfs_open_proxy_file_operations;
extern const struct file_operations debugfs_full_proxy_file_operations;
+struct debugfs_fsdata {
+ const struct file_operations *real_fops;
+ refcount_t active_users;
+ struct completion active_users_drained;
+};
+
+/*
+ * A dentry's ->d_fsdata either points to the real fops or to a
+ * dynamically allocated debugfs_fsdata instance.
+ * In order to distinguish between these two cases, a real fops
+ * pointer gets its lowest bit set.
+ */
+#define DEBUGFS_FSDATA_IS_REAL_FOPS_BIT BIT(0)
+
#endif /* _DEBUGFS_INTERNAL_H_ */
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index b93efc8feecd..f36ecc2a5712 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* debugfs.h - a tiny little debug file system
*
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
* debugfs is for people to use instead of /proc or /sys.
* See Documentation/filesystems/ for more details.
*/
@@ -23,7 +20,6 @@
struct device;
struct file_operations;
-struct srcu_struct;
struct debugfs_blob_wrapper {
void *data;
@@ -43,25 +39,6 @@ struct debugfs_regset32 {
extern struct dentry *arch_debugfs_dir;
-extern struct srcu_struct debugfs_srcu;
-
-/**
- * debugfs_real_fops - getter for the real file operation
- * @filp: a pointer to a struct file
- *
- * Must only be called under the protection established by
- * debugfs_use_file_start().
- */
-static inline const struct file_operations *debugfs_real_fops(const struct file *filp)
- __must_hold(&debugfs_srcu)
-{
- /*
- * Neither the pointer to the struct file_operations, nor its
- * contents ever change -- srcu_dereference() is not needed here.
- */
- return filp->f_path.dentry->d_fsdata;
-}
-
#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \
static int __fops ## _open(struct inode *inode, struct file *file) \
{ \
@@ -107,10 +84,10 @@ struct dentry *debugfs_create_automount(const char *name,
void debugfs_remove(struct dentry *dentry);
void debugfs_remove_recursive(struct dentry *dentry);
-int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx)
- __acquires(&debugfs_srcu);
+const struct file_operations *debugfs_real_fops(const struct file *filp);
-void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu);
+int debugfs_file_get(struct dentry *dentry);
+void debugfs_file_put(struct dentry *dentry);
ssize_t debugfs_attr_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos);
@@ -239,15 +216,12 @@ static inline void debugfs_remove(struct dentry *dentry)
static inline void debugfs_remove_recursive(struct dentry *dentry)
{ }
-static inline int debugfs_use_file_start(const struct dentry *dentry,
- int *srcu_idx)
- __acquires(&debugfs_srcu)
+static inline int debugfs_file_get(struct dentry *dentry)
{
return 0;
}
-static inline void debugfs_use_file_finish(int srcu_idx)
- __releases(&debugfs_srcu)
+static inline void debugfs_file_put(struct dentry *dentry)
{ }
static inline ssize_t debugfs_attr_read(struct file *file, char __user *buf,
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5402e3954659..8ffd891857ab 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -280,7 +280,6 @@ config PAGE_OWNER
config DEBUG_FS
bool "Debug Filesystem"
- select SRCU
help
debugfs is a virtual file system that kernel developers use to put
debugging files into. Enable this option to be able to read and
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-10 04:11:12 +0000