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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2024-07-15 14:03:44 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2024-07-15 14:03:44 -0700
commita23e1966932464e1c5226cb9ac4ce1d5fc10ba22 (patch)
treebf5f1b57faa01ca31656bfc48c7d6b6f0bc39189 /fs/file_table.c
parent7c7b1be19b228b450c2945ec379d7fc6bfef9852 (diff)
parentf3efefb6fdcce604413135bd8d4c5568e53a1f13 (diff)
Merge branch 'next' into for-linus
Prepare input updates for 6.11 merge window.
Diffstat (limited to 'fs/file_table.c')
-rw-r--r--fs/file_table.c150
1 files changed, 95 insertions, 55 deletions
diff --git a/fs/file_table.c b/fs/file_table.c
index fc7d677ff5ad..4f03beed4737 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -26,7 +26,6 @@
#include <linux/percpu_counter.h>
#include <linux/percpu.h>
#include <linux/task_work.h>
-#include <linux/ima.h>
#include <linux/swap.h>
#include <linux/kmemleak.h>
@@ -40,14 +39,14 @@ static struct files_stat_struct files_stat = {
};
/* SLAB cache for file structures */
-static struct kmem_cache *filp_cachep __read_mostly;
+static struct kmem_cache *filp_cachep __ro_after_init;
static struct percpu_counter nr_files __cacheline_aligned_in_smp;
-/* Container for backing file with optional real path */
+/* Container for backing file with optional user path */
struct backing_file {
struct file file;
- struct path real_path;
+ struct path user_path;
};
static inline struct backing_file *backing_file(struct file *f)
@@ -55,31 +54,24 @@ static inline struct backing_file *backing_file(struct file *f)
return container_of(f, struct backing_file, file);
}
-struct path *backing_file_real_path(struct file *f)
+struct path *backing_file_user_path(struct file *f)
{
- return &backing_file(f)->real_path;
-}
-EXPORT_SYMBOL_GPL(backing_file_real_path);
-
-static void file_free_rcu(struct rcu_head *head)
-{
- struct file *f = container_of(head, struct file, f_rcuhead);
-
- put_cred(f->f_cred);
- if (unlikely(f->f_mode & FMODE_BACKING))
- kfree(backing_file(f));
- else
- kmem_cache_free(filp_cachep, f);
+ return &backing_file(f)->user_path;
}
+EXPORT_SYMBOL_GPL(backing_file_user_path);
static inline void file_free(struct file *f)
{
security_file_free(f);
- if (unlikely(f->f_mode & FMODE_BACKING))
- path_put(backing_file_real_path(f));
if (likely(!(f->f_mode & FMODE_NOACCOUNT)))
percpu_counter_dec(&nr_files);
- call_rcu(&f->f_rcuhead, file_free_rcu);
+ put_cred(f->f_cred);
+ if (unlikely(f->f_mode & FMODE_BACKING)) {
+ path_put(backing_file_user_path(f));
+ kfree(backing_file(f));
+ } else {
+ kmem_cache_free(filp_cachep, f);
+ }
}
/*
@@ -137,7 +129,6 @@ static struct ctl_table fs_stat_sysctls[] = {
.extra1 = &sysctl_nr_open_min,
.extra2 = &sysctl_nr_open_max,
},
- { }
};
static int __init init_fs_stat_sysctls(void)
@@ -164,7 +155,6 @@ static int init_file(struct file *f, int flags, const struct cred *cred)
return error;
}
- atomic_long_set(&f->f_count, 1);
rwlock_init(&f->f_owner.lock);
spin_lock_init(&f->f_lock);
mutex_init(&f->f_pos_lock);
@@ -172,6 +162,12 @@ static int init_file(struct file *f, int flags, const struct cred *cred)
f->f_mode = OPEN_FMODE(flags);
/* f->f_version: 0 */
+ /*
+ * We're SLAB_TYPESAFE_BY_RCU so initialize f_count last. While
+ * fget-rcu pattern users need to be able to handle spurious
+ * refcount bumps we should reinitialize the reused file first.
+ */
+ atomic_long_set(&f->f_count, 1);
return 0;
}
@@ -279,21 +275,15 @@ struct file *alloc_empty_backing_file(int flags, const struct cred *cred)
}
/**
- * alloc_file - allocate and initialize a 'struct file'
+ * file_init_path - initialize a 'struct file' based on path
*
+ * @file: the file to set up
* @path: the (dentry, vfsmount) pair for the new file
- * @flags: O_... flags with which the new file will be opened
* @fop: the 'struct file_operations' for the new file
*/
-static struct file *alloc_file(const struct path *path, int flags,
- const struct file_operations *fop)
+static void file_init_path(struct file *file, const struct path *path,
+ const struct file_operations *fop)
{
- struct file *file;
-
- file = alloc_empty_file(flags, current_cred());
- if (IS_ERR(file))
- return file;
-
file->f_path = *path;
file->f_inode = path->dentry->d_inode;
file->f_mapping = path->dentry->d_inode->i_mapping;
@@ -312,27 +302,51 @@ static struct file *alloc_file(const struct path *path, int flags,
file->f_op = fop;
if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
i_readcount_inc(path->dentry->d_inode);
+}
+
+/**
+ * alloc_file - allocate and initialize a 'struct file'
+ *
+ * @path: the (dentry, vfsmount) pair for the new file
+ * @flags: O_... flags with which the new file will be opened
+ * @fop: the 'struct file_operations' for the new file
+ */
+static struct file *alloc_file(const struct path *path, int flags,
+ const struct file_operations *fop)
+{
+ struct file *file;
+
+ file = alloc_empty_file(flags, current_cred());
+ if (!IS_ERR(file))
+ file_init_path(file, path, fop);
return file;
}
-struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,
- const char *name, int flags,
- const struct file_operations *fops)
+static inline int alloc_path_pseudo(const char *name, struct inode *inode,
+ struct vfsmount *mnt, struct path *path)
{
- static const struct dentry_operations anon_ops = {
- .d_dname = simple_dname
- };
struct qstr this = QSTR_INIT(name, strlen(name));
+
+ path->dentry = d_alloc_pseudo(mnt->mnt_sb, &this);
+ if (!path->dentry)
+ return -ENOMEM;
+ path->mnt = mntget(mnt);
+ d_instantiate(path->dentry, inode);
+ return 0;
+}
+
+struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,
+ const char *name, int flags,
+ const struct file_operations *fops)
+{
+ int ret;
struct path path;
struct file *file;
- path.dentry = d_alloc_pseudo(mnt->mnt_sb, &this);
- if (!path.dentry)
- return ERR_PTR(-ENOMEM);
- if (!mnt->mnt_sb->s_d_op)
- d_set_d_op(path.dentry, &anon_ops);
- path.mnt = mntget(mnt);
- d_instantiate(path.dentry, inode);
+ ret = alloc_path_pseudo(name, inode, mnt, &path);
+ if (ret)
+ return ERR_PTR(ret);
+
file = alloc_file(&path, flags, fops);
if (IS_ERR(file)) {
ihold(inode);
@@ -342,6 +356,30 @@ struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,
}
EXPORT_SYMBOL(alloc_file_pseudo);
+struct file *alloc_file_pseudo_noaccount(struct inode *inode,
+ struct vfsmount *mnt, const char *name,
+ int flags,
+ const struct file_operations *fops)
+{
+ int ret;
+ struct path path;
+ struct file *file;
+
+ ret = alloc_path_pseudo(name, inode, mnt, &path);
+ if (ret)
+ return ERR_PTR(ret);
+
+ file = alloc_empty_file_noaccount(flags, current_cred());
+ if (IS_ERR(file)) {
+ ihold(inode);
+ path_put(&path);
+ return file;
+ }
+ file_init_path(file, &path, fops);
+ return file;
+}
+EXPORT_SYMBOL_GPL(alloc_file_pseudo_noaccount);
+
struct file *alloc_file_clone(struct file *base, int flags,
const struct file_operations *fops)
{
@@ -375,7 +413,7 @@ static void __fput(struct file *file)
eventpoll_release(file);
locks_remove_file(file);
- ima_file_free(file);
+ security_file_release(file);
if (unlikely(file->f_flags & FASYNC)) {
if (file->f_op->fasync)
file->f_op->fasync(-1, file, 0);
@@ -409,7 +447,7 @@ static void delayed_fput(struct work_struct *unused)
static void ____fput(struct callback_head *work)
{
- __fput(container_of(work, struct file, f_rcuhead));
+ __fput(container_of(work, struct file, f_task_work));
}
/*
@@ -435,9 +473,13 @@ void fput(struct file *file)
if (atomic_long_dec_and_test(&file->f_count)) {
struct task_struct *task = current;
+ if (unlikely(!(file->f_mode & (FMODE_BACKING | FMODE_OPENED)))) {
+ file_free(file);
+ return;
+ }
if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) {
- init_task_work(&file->f_rcuhead, ____fput);
- if (!task_work_add(task, &file->f_rcuhead, TWA_RESUME))
+ init_task_work(&file->f_task_work, ____fput);
+ if (!task_work_add(task, &file->f_task_work, TWA_RESUME))
return;
/*
* After this task has run exit_task_work(),
@@ -461,11 +503,8 @@ void fput(struct file *file)
*/
void __fput_sync(struct file *file)
{
- if (atomic_long_dec_and_test(&file->f_count)) {
- struct task_struct *task = current;
- BUG_ON(!(task->flags & PF_KTHREAD));
+ if (atomic_long_dec_and_test(&file->f_count))
__fput(file);
- }
}
EXPORT_SYMBOL(fput);
@@ -474,7 +513,8 @@ EXPORT_SYMBOL(__fput_sync);
void __init files_init(void)
{
filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
- SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT, NULL);
+ SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN |
+ SLAB_PANIC | SLAB_ACCOUNT, NULL);
percpu_counter_init(&nr_files, 0, GFP_KERNEL);
}