From dc50eab76b709d68175a358d6e23a5a3890764d3 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 19:39:57 +0200 Subject: Merging upstream version 6.7.7. Signed-off-by: Daniel Baumann --- fs/file_table.c | 51 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 31 insertions(+), 20 deletions(-) (limited to 'fs/file_table.c') diff --git a/fs/file_table.c b/fs/file_table.c index ee21b3da9d..de4a2915bf 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -40,14 +40,14 @@ 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 +55,36 @@ 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; + return &backing_file(f)->user_path; } -EXPORT_SYMBOL_GPL(backing_file_real_path); +EXPORT_SYMBOL_GPL(backing_file_user_path); -static void file_free_rcu(struct rcu_head *head) +static inline void file_free(struct file *f) { - struct file *f = container_of(head, struct file, f_rcuhead); - + security_file_free(f); + if (likely(!(f->f_mode & FMODE_NOACCOUNT))) + percpu_counter_dec(&nr_files); put_cred(f->f_cred); - if (unlikely(f->f_mode & FMODE_BACKING)) + if (unlikely(f->f_mode & FMODE_BACKING)) { + path_put(backing_file_user_path(f)); kfree(backing_file(f)); - else + } else { kmem_cache_free(filp_cachep, f); + } } -static inline void file_free(struct file *f) +void release_empty_file(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); + WARN_ON_ONCE(f->f_mode & (FMODE_BACKING | FMODE_OPENED)); + if (atomic_long_dec_and_test(&f->f_count)) { + security_file_free(f); + put_cred(f->f_cred); + if (likely(!(f->f_mode & FMODE_NOACCOUNT))) + percpu_counter_dec(&nr_files); + kmem_cache_free(filp_cachep, f); + } } /* @@ -164,7 +169,6 @@ 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 +176,12 @@ 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; } @@ -471,7 +481,8 @@ 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); } -- cgit v1.2.3