From 8a32c441c1609f80e55df75422324a1151208f40 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 21 Nov 2011 12:32:23 -0800 Subject: freezer: implement and use kthread_freezable_should_stop() Writeback and thinkpad_acpi have been using thaw_process() to prevent deadlock between the freezer and kthread_stop(); unfortunately, this is inherently racy - nothing prevents freezing from happening between thaw_process() and kthread_stop(). This patch implements kthread_freezable_should_stop() which enters refrigerator if necessary but is guaranteed to return if kthread_stop() is invoked. Both thaw_process() users are converted to use the new function. Note that this deadlock condition exists for many of freezable kthreads. They need to be converted to use the new should_stop or freezable workqueue. Tested with synthetic test case. Signed-off-by: Tejun Heo Acked-by: Henrique de Moraes Holschuh Cc: Jens Axboe Cc: Oleg Nesterov --- fs/fs-writeback.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 73c3992b2bb4..271fde50f0ee 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -947,7 +947,7 @@ int bdi_writeback_thread(void *data) trace_writeback_thread_start(bdi); - while (!kthread_should_stop()) { + while (!kthread_freezable_should_stop(NULL)) { /* * Remove own delayed wake-up timer, since we are already awake * and we'll take care of the preriodic write-back. @@ -977,8 +977,6 @@ int bdi_writeback_thread(void *data) */ schedule(); } - - try_to_freeze(); } /* Flush any work that raced with us exiting */ -- cgit From 786228ab3095fe18dba3bc0d62055a123991d9d9 Mon Sep 17 00:00:00 2001 From: Marcos Paulo de Souza Date: Wed, 23 Nov 2011 20:56:45 +0800 Subject: writeback: Fix issue on make htmldocs Document the @reason parameter to make "make htmldocs" happy. Acked-by: Randy Dunlap Signed-off-by: Marcos Paulo de Souza Signed-off-by: Wu Fengguang --- fs/fs-writeback.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 73c3992b2bb4..ac86f8b3e3cb 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -156,6 +156,7 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, * bdi_start_writeback - start writeback * @bdi: the backing device to write from * @nr_pages: the number of pages to write + * @reason: reason why some writeback work was initiated * * Description: * This does WB_SYNC_NONE opportunistic writeback. The IO is only @@ -1223,6 +1224,7 @@ static void wait_sb_inodes(struct super_block *sb) * writeback_inodes_sb_nr - writeback dirty inodes from given super_block * @sb: the superblock * @nr: the number of pages to write + * @reason: reason why some writeback work initiated * * Start writeback on some inodes on this super_block. No guarantees are made * on how many (if any) will be written, and this function does not wait @@ -1251,6 +1253,7 @@ EXPORT_SYMBOL(writeback_inodes_sb_nr); /** * writeback_inodes_sb - writeback dirty inodes from given super_block * @sb: the superblock + * @reason: reason why some writeback work was initiated * * Start writeback on some inodes on this super_block. No guarantees are made * on how many (if any) will be written, and this function does not wait @@ -1265,6 +1268,7 @@ EXPORT_SYMBOL(writeback_inodes_sb); /** * writeback_inodes_sb_if_idle - start writeback if none underway * @sb: the superblock + * @reason: reason why some writeback work was initiated * * Invoke writeback_inodes_sb if no writeback is currently underway. * Returns 1 if writeback was started, 0 if not. @@ -1285,6 +1289,7 @@ EXPORT_SYMBOL(writeback_inodes_sb_if_idle); * writeback_inodes_sb_if_idle - start writeback if none underway * @sb: the superblock * @nr: the number of pages to write + * @reason: reason why some writeback work was initiated * * Invoke writeback_inodes_sb if no writeback is currently underway. * Returns 1 if writeback was started, 0 if not. -- cgit From b3bba872ddb0320a7ecb54decae53c13ceb2ed4c Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Thu, 8 Dec 2011 16:53:54 -0600 Subject: writeback: show writeback reason with __print_symbolic This makes the binary trace understandable by trace-cmd. CC: Dave Chinner CC: Curt Wohlgemuth CC: Steven Rostedt Signed-off-by: Wu Fengguang --- fs/fs-writeback.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index ac86f8b3e3cb..517f211a3bd4 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -47,17 +47,6 @@ struct wb_writeback_work { struct completion *done; /* set if the caller waits */ }; -const char *wb_reason_name[] = { - [WB_REASON_BACKGROUND] = "background", - [WB_REASON_TRY_TO_FREE_PAGES] = "try_to_free_pages", - [WB_REASON_SYNC] = "sync", - [WB_REASON_PERIODIC] = "periodic", - [WB_REASON_LAPTOP_TIMER] = "laptop_timer", - [WB_REASON_FREE_MORE_MEM] = "free_more_memory", - [WB_REASON_FS_FREE_SPACE] = "fs_free_space", - [WB_REASON_FORKER_THREAD] = "forker_thread" -}; - /* * Include the creation of the trace points after defining the * wb_writeback_work structure so that the definition remains local to this -- cgit From ff01bb4832651c6d25ac509a06a10fcbd75c461c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 16 Sep 2011 02:31:11 -0400 Subject: fs: move code out of buffer.c Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin Cc: Al Viro Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- fs/fs-writeback.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 517f211a3bd4..80a4574028f1 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include "internal.h" -- cgit