diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c index 1fb6ff77fd89..bb696b29ee2c 100644 --- a/drivers/gpu/drm/i915/gt/shmem_utils.c +++ b/drivers/gpu/drm/i915/gt/shmem_utils.c @@ -40,7 +40,7 @@ struct file *shmem_create_from_object(struct drm_i915_gem_object *obj) if (i915_gem_object_is_shmem(obj)) { file = obj->base.filp; - atomic_long_inc(&file->f_count); + get_file(file); return file; } diff --git a/drivers/gpu/drm/vmwgfx/ttm_object.c b/drivers/gpu/drm/vmwgfx/ttm_object.c index 3353e97687d1..a17e62867f3b 100644 --- a/drivers/gpu/drm/vmwgfx/ttm_object.c +++ b/drivers/gpu/drm/vmwgfx/ttm_object.c @@ -471,7 +471,7 @@ void ttm_object_device_release(struct ttm_object_device **p_tdev) */ static bool __must_check get_dma_buf_unless_doomed(struct dma_buf *dmabuf) { - return atomic_long_inc_not_zero(&dmabuf->file->f_count) != 0L; + return file_ref_get(&dmabuf->file->f_ref); } /** diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 1ae4542f0bd8..212383cefe6c 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1002,7 +1002,7 @@ static struct file *epi_fget(const struct epitem *epi) struct file *file; file = epi->ffd.file; - if (!atomic_long_inc_not_zero(&file->f_count)) + if (!file_ref_get(&file->f_ref)) file = NULL; return file; } diff --git a/fs/file.c b/fs/file.c index ab15e2a3d280..9598c577f713 100644 --- a/fs/file.c +++ b/fs/file.c @@ -902,7 +902,7 @@ static struct file *__get_file_rcu(struct file __rcu **f) if (!file) return NULL; - if (unlikely(!atomic_long_inc_not_zero(&file->f_count))) + if (unlikely(!file_ref_get(&file->f_ref))) return ERR_PTR(-EAGAIN); file_reloaded = rcu_dereference_raw(*f); @@ -916,8 +916,8 @@ static struct file *__get_file_rcu(struct file __rcu **f) OPTIMIZER_HIDE_VAR(file_reloaded_cmp); /* - * atomic_long_inc_not_zero() above provided a full memory - * barrier when we acquired a reference. + * file_ref_get() above provided a full memory barrier when we + * acquired a reference. * * This is paired with the write barrier from assigning to the * __rcu protected file pointer so that if that pointer still @@ -1015,11 +1015,11 @@ static inline struct file *__fget_files_rcu(struct files_struct *files, * We need to confirm it by incrementing the refcount * and then check the lookup again. * - * atomic_long_inc_not_zero() gives us a full memory - * barrier. We only really need an 'acquire' one to - * protect the loads below, but we don't have that. + * file_ref_get() gives us a full memory barrier. We + * only really need an 'acquire' one to protect the + * loads below, but we don't have that. */ - if (unlikely(!atomic_long_inc_not_zero(&file->f_count))) + if (unlikely(!file_ref_get(&file->f_ref))) continue; /* diff --git a/fs/file_table.c b/fs/file_table.c index 4b23eb7b79dd..db4fde6fe620 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -169,16 +169,32 @@ static int init_file(struct file *f, int flags, const struct cred *cred) * the respective member when opening the file. */ mutex_init(&f->f_pos_lock); - f->f_flags = flags; - f->f_mode = OPEN_FMODE(flags); - /* f->f_version: 0 */ + memset(&f->f_path, 0, sizeof(f->f_path)); + memset(&f->f_ra, 0, sizeof(f->f_ra)); + + f->f_flags = flags; + f->f_mode = OPEN_FMODE(flags); + + f->f_op = NULL; + f->f_mapping = NULL; + f->private_data = NULL; + f->f_inode = NULL; + f->f_owner = NULL; +#ifdef CONFIG_EPOLL + f->f_ep = NULL; +#endif + + f->f_iocb_flags = 0; + f->f_pos = 0; + f->f_wb_err = 0; + f->f_sb_err = 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); + file_ref_init(&f->f_ref, 1); return 0; } @@ -210,7 +226,7 @@ struct file *alloc_empty_file(int flags, const struct cred *cred) goto over; } - f = kmem_cache_zalloc(filp_cachep, GFP_KERNEL); + f = kmem_cache_alloc(filp_cachep, GFP_KERNEL); if (unlikely(!f)) return ERR_PTR(-ENOMEM); @@ -244,7 +260,7 @@ struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred) struct file *f; int error; - f = kmem_cache_zalloc(filp_cachep, GFP_KERNEL); + f = kmem_cache_alloc(filp_cachep, GFP_KERNEL); if (unlikely(!f)) return ERR_PTR(-ENOMEM); @@ -271,7 +287,7 @@ struct file *alloc_empty_backing_file(int flags, const struct cred *cred) struct backing_file *ff; int error; - ff = kmem_cache_zalloc(bfilp_cachep, GFP_KERNEL); + ff = kmem_cache_alloc(bfilp_cachep, GFP_KERNEL); if (unlikely(!ff)) return ERR_PTR(-ENOMEM); @@ -483,7 +499,7 @@ static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput); void fput(struct file *file) { - if (atomic_long_dec_and_test(&file->f_count)) { + if (file_ref_put(&file->f_ref)) { struct task_struct *task = current; if (unlikely(!(file->f_mode & (FMODE_BACKING | FMODE_OPENED)))) { @@ -516,7 +532,7 @@ void fput(struct file *file) */ void __fput_sync(struct file *file) { - if (atomic_long_dec_and_test(&file->f_count)) + if (file_ref_put(&file->f_ref)) __fput(file); } diff --git a/include/linux/fs.h b/include/linux/fs.h index e3c603d01337..c13f648a1c13 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -45,6 +45,7 @@ #include #include #include +#include #include #include @@ -1005,7 +1006,7 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) /** * struct file - Represents a file - * @f_count: reference count + * @f_ref: reference count * @f_lock: Protects f_ep, f_flags. Must not be taken from IRQ context. * @f_mode: FMODE_* flags often used in hotpaths * @f_op: file operations @@ -1030,7 +1031,7 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) * @f_freeptr: Pointer used by SLAB_TYPESAFE_BY_RCU file cache (don't touch.) */ struct file { - atomic_long_t f_count; + file_ref_t f_ref; spinlock_t f_lock; fmode_t f_mode; const struct file_operations *f_op; @@ -1078,15 +1079,14 @@ struct file_handle { static inline struct file *get_file(struct file *f) { - long prior = atomic_long_fetch_inc_relaxed(&f->f_count); - WARN_ONCE(!prior, "struct file::f_count incremented from zero; use-after-free condition present!\n"); + file_ref_inc(&f->f_ref); return f; } struct file *get_file_rcu(struct file __rcu **f); struct file *get_file_active(struct file **f); -#define file_count(x) atomic_long_read(&(x)->f_count) +#define file_count(f) file_ref_read(&(f)->f_ref) #define MAX_NON_LFS ((1UL<<31) - 1)