From 17bd55d037a02b04d9119511cfd1a4b985d20f63 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 23 Dec 2009 07:57:07 -0500 Subject: fs-writeback: Add helper function to start writeback if idle ext4, at least, would like to start pushing on writeback if it starts to get close to ENOSPC when reserving worst-case blocks for delalloc writes. Writing out delalloc data will convert those worst-case predictions into usually smaller actual usage, freeing up space before we hit ENOSPC based on this speculation. Thanks to Jens for the suggestion for the helper function, & the naming help. I've made the helper return status on whether writeback was started even though I don't plan to use it in the ext4 patch; it seems like it would be potentially useful to test this in some cases. Signed-off-by: Eric Sandeen Acked-by: Jan Kara --- fs/fs-writeback.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 49bc1b8e8f1..f6c2155e002 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1186,6 +1186,23 @@ void writeback_inodes_sb(struct super_block *sb) } EXPORT_SYMBOL(writeback_inodes_sb); +/** + * writeback_inodes_sb_if_idle - start writeback if none underway + * @sb: the superblock + * + * Invoke writeback_inodes_sb if no writeback is currently underway. + * Returns 1 if writeback was started, 0 if not. + */ +int writeback_inodes_sb_if_idle(struct super_block *sb) +{ + if (!writeback_in_progress(sb->s_bdi)) { + writeback_inodes_sb(sb); + return 1; + } else + return 0; +} +EXPORT_SYMBOL(writeback_inodes_sb_if_idle); + /** * sync_inodes_sb - sync sb inode pages * @sb: the superblock -- cgit v1.2.3-70-g09d2 From 4b6764fa9e25cf628e42bbd192eca1e0b8e59061 Mon Sep 17 00:00:00 2001 From: Jaswinder Singh Rajput Date: Fri, 1 Jan 2010 20:35:23 -0800 Subject: writeback: add missing kernel-doc notation Fix the following htmldocs warning: Warning(fs/fs-writeback.c:255): No description found for parameter 'sb' Signed-off-by: Jaswinder Singh Rajput Signed-off-by: Randy Dunlap Acked-by: Wu Fengguang Cc: Peter Zijlstra Cc: Jan Kara Cc: Jens Axboe Signed-off-by: Linus Torvalds --- fs/fs-writeback.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index f6c2155e002..1a7c42c64ff 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -242,6 +242,7 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi, /** * bdi_start_writeback - start writeback * @bdi: the backing device to write from + * @sb: write inodes from this super_block * @nr_pages: the number of pages to write * * Description: -- cgit v1.2.3-70-g09d2