From 989a2979205dd34269382b357e6d4b4b6956b889 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 14 Apr 2010 09:55:35 +0000 Subject: fasync: RCU and fine grained locking kill_fasync() uses a central rwlock, candidate for RCU conversion, to avoid cache line ping pongs on SMP. fasync_remove_entry() and fasync_add_entry() can disable IRQS on a short section instead during whole list scan. Use a spinlock per fasync_struct to synchronize kill_fasync_rcu() and fasync_{remove|add}_entry(). This spinlock is IRQ safe, so sock_fasync() doesnt need its own implementation and can use fasync_helper(), to reduce code size and complexity. We can remove __kill_fasync() direct use in net/socket.c, and rename it to kill_fasync_rcu(). Signed-off-by: Eric Dumazet Cc: Paul E. McKenney Cc: Lai Jiangshan Signed-off-by: David S. Miller --- include/linux/fs.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index 39d57bc6cc71..018d382f6f92 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1280,10 +1280,12 @@ static inline int lock_may_write(struct inode *inode, loff_t start, struct fasync_struct { - int magic; - int fa_fd; - struct fasync_struct *fa_next; /* singly linked list */ - struct file *fa_file; + spinlock_t fa_lock; + int magic; + int fa_fd; + struct fasync_struct *fa_next; /* singly linked list */ + struct file *fa_file; + struct rcu_head fa_rcu; }; #define FASYNC_MAGIC 0x4601 @@ -1292,8 +1294,6 @@ struct fasync_struct { extern int fasync_helper(int, struct file *, int, struct fasync_struct **); /* can be called from interrupts */ extern void kill_fasync(struct fasync_struct **, int, int); -/* only for net: no internal synchronization */ -extern void __kill_fasync(struct fasync_struct *, int, int); extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force); extern int f_setown(struct file *filp, unsigned long arg, int force); -- cgit v1.2.2 From 6a727b43be8b005609e893a80af980808012cfdb Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Sat, 1 May 2010 23:51:22 +0200 Subject: FS / libfs: Implement simple_write_to_buffer It will be used in suspend code and serves as an easy wrap around copy_from_user. Similar to simple_read_from_buffer, it takes care of transfers with proper lengths depending on available and count parameters and advances ppos appropriately. Signed-off-by: Jiri Slaby Signed-off-by: Rafael J. Wysocki --- include/linux/fs.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index 44f35aea2f1f..948bd2bfb1de 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2362,6 +2362,8 @@ extern void simple_release_fs(struct vfsmount **mount, int *count); extern ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, const void *from, size_t available); +extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, + const void __user *from, size_t count); extern int simple_fsync(struct file *, struct dentry *, int); -- cgit v1.2.2