diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/fs.h | 19 | ||||
| -rw-r--r-- | include/linux/percpu-rwsem.h | 20 |
2 files changed, 29 insertions, 10 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 9120fd0759cd..81f8f0aec563 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1316,6 +1316,7 @@ struct sb_writers { unsigned short frozen; /* Is sb frozen? */ int freeze_kcount; /* How many kernel freeze requests? */ int freeze_ucount; /* How many userspace freeze requests? */ + const void *freeze_owner; /* Owner of the freeze */ struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS]; }; @@ -1789,7 +1790,7 @@ static inline void __sb_end_write(struct super_block *sb, int level) static inline void __sb_start_write(struct super_block *sb, int level) { - percpu_down_read(sb->s_writers.rw_sem + level - 1); + percpu_down_read_freezable(sb->s_writers.rw_sem + level - 1, true); } static inline bool __sb_start_write_trylock(struct super_block *sb, int level) @@ -2288,6 +2289,7 @@ extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, * @FREEZE_HOLDER_KERNEL: kernel wants to freeze or thaw filesystem * @FREEZE_HOLDER_USERSPACE: userspace wants to freeze or thaw filesystem * @FREEZE_MAY_NEST: whether nesting freeze and thaw requests is allowed + * @FREEZE_EXCL: a freeze that can only be undone by the owner * * Indicate who the owner of the freeze or thaw request is and whether * the freeze needs to be exclusive or can nest. @@ -2301,6 +2303,7 @@ enum freeze_holder { FREEZE_HOLDER_KERNEL = (1U << 0), FREEZE_HOLDER_USERSPACE = (1U << 1), FREEZE_MAY_NEST = (1U << 2), + FREEZE_EXCL = (1U << 3), }; struct super_operations { @@ -2314,9 +2317,9 @@ struct super_operations { void (*evict_inode) (struct inode *); void (*put_super) (struct super_block *); int (*sync_fs)(struct super_block *sb, int wait); - int (*freeze_super) (struct super_block *, enum freeze_holder who); + int (*freeze_super) (struct super_block *, enum freeze_holder who, const void *owner); int (*freeze_fs) (struct super_block *); - int (*thaw_super) (struct super_block *, enum freeze_holder who); + int (*thaw_super) (struct super_block *, enum freeze_holder who, const void *owner); int (*unfreeze_fs) (struct super_block *); int (*statfs) (struct dentry *, struct kstatfs *); int (*remount_fs) (struct super_block *, int *, char *); @@ -2726,8 +2729,10 @@ extern int unregister_filesystem(struct file_system_type *); extern int vfs_statfs(const struct path *, struct kstatfs *); extern int user_statfs(const char __user *, struct kstatfs *); extern int fd_statfs(int, struct kstatfs *); -int freeze_super(struct super_block *super, enum freeze_holder who); -int thaw_super(struct super_block *super, enum freeze_holder who); +int freeze_super(struct super_block *super, enum freeze_holder who, + const void *freeze_owner); +int thaw_super(struct super_block *super, enum freeze_holder who, + const void *freeze_owner); extern __printf(2, 3) int super_setup_bdi_name(struct super_block *sb, char *fmt, ...); extern int super_setup_bdi(struct super_block *sb); @@ -3536,9 +3541,11 @@ extern void put_filesystem(struct file_system_type *fs); extern struct file_system_type *get_fs_type(const char *name); extern void drop_super(struct super_block *sb); extern void drop_super_exclusive(struct super_block *sb); -extern void iterate_supers(void (*)(struct super_block *, void *), void *); +extern void iterate_supers(void (*f)(struct super_block *, void *), void *arg); extern void iterate_supers_type(struct file_system_type *, void (*)(struct super_block *, void *), void *); +void filesystems_freeze(void); +void filesystems_thaw(void); extern int dcache_dir_open(struct inode *, struct file *); extern int dcache_dir_close(struct inode *, struct file *); diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index af7d75ede619..288f5235649a 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -43,9 +43,10 @@ is_static struct percpu_rw_semaphore name = { \ #define DEFINE_STATIC_PERCPU_RWSEM(name) \ __DEFINE_PERCPU_RWSEM(name, static) -extern bool __percpu_down_read(struct percpu_rw_semaphore *, bool); +extern bool __percpu_down_read(struct percpu_rw_semaphore *, bool, bool); -static inline void percpu_down_read(struct percpu_rw_semaphore *sem) +static inline void percpu_down_read_internal(struct percpu_rw_semaphore *sem, + bool freezable) { might_sleep(); @@ -63,7 +64,7 @@ static inline void percpu_down_read(struct percpu_rw_semaphore *sem) if (likely(rcu_sync_is_idle(&sem->rss))) this_cpu_inc(*sem->read_count); else - __percpu_down_read(sem, false); /* Unconditional memory barrier */ + __percpu_down_read(sem, false, freezable); /* Unconditional memory barrier */ /* * The preempt_enable() prevents the compiler from * bleeding the critical section out. @@ -71,6 +72,17 @@ static inline void percpu_down_read(struct percpu_rw_semaphore *sem) preempt_enable(); } +static inline void percpu_down_read(struct percpu_rw_semaphore *sem) +{ + percpu_down_read_internal(sem, false); +} + +static inline void percpu_down_read_freezable(struct percpu_rw_semaphore *sem, + bool freeze) +{ + percpu_down_read_internal(sem, freeze); +} + static inline bool percpu_down_read_trylock(struct percpu_rw_semaphore *sem) { bool ret = true; @@ -82,7 +94,7 @@ static inline bool percpu_down_read_trylock(struct percpu_rw_semaphore *sem) if (likely(rcu_sync_is_idle(&sem->rss))) this_cpu_inc(*sem->read_count); else - ret = __percpu_down_read(sem, true); /* Unconditional memory barrier */ + ret = __percpu_down_read(sem, true, false); /* Unconditional memory barrier */ preempt_enable(); /* * The barrier() from preempt_enable() prevents the compiler from |