From 7b7a8665edd8db733980389b098530f9e4f630b2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 4 Sep 2013 15:04:39 +0200 Subject: direct-io: Implement generic deferred AIO completions Add support to the core direct-io code to defer AIO completions to user context using a workqueue. This replaces opencoded and less efficient code in XFS and ext4 (we save a memory allocation for each direct IO) and will be needed to properly support O_(D)SYNC for AIO. The communication between the filesystem and the direct I/O code requires a new buffer head flag, which is a bit ugly but not avoidable until the direct I/O code stops abusing the buffer_head structure for communicating with the filesystems. Currently this creates a per-superblock unbound workqueue for these completions, which is taken from an earlier patch by Jan Kara. I'm not really convinced about this use and would prefer a "normal" global workqueue with a high concurrency limit, but this needs further discussion. JK: Fixed ext4 part, dynamic allocation of the workqueue. Signed-off-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Al Viro --- fs/super.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'fs/super.c') diff --git a/fs/super.c b/fs/super.c index 68307c029228..5536a95186e2 100644 --- a/fs/super.c +++ b/fs/super.c @@ -152,15 +152,9 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags) static const struct super_operations default_op; if (s) { - if (security_sb_alloc(s)) { - /* - * We cannot call security_sb_free() without - * security_sb_alloc() succeeding. So bail out manually - */ - kfree(s); - s = NULL; - goto out; - } + if (security_sb_alloc(s)) + goto out_free_sb; + #ifdef CONFIG_SMP s->s_files = alloc_percpu(struct list_head); if (!s->s_files) @@ -228,6 +222,7 @@ err_out: free_percpu(s->s_files); #endif destroy_sb_writers(s); +out_free_sb: kfree(s); s = NULL; goto out; @@ -414,6 +409,11 @@ void generic_shutdown_super(struct super_block *sb) evict_inodes(sb); + if (sb->s_dio_done_wq) { + destroy_workqueue(sb->s_dio_done_wq); + sb->s_dio_done_wq = NULL; + } + if (sop->put_super) sop->put_super(sb); -- cgit v1.2.3