From d8a8559cd7a9ccac98d5f6f13297a2ff68a43627 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 2 Sep 2009 12:34:32 +0200 Subject: writeback: get rid of generic_sync_sb_inodes() export This adds two new exported functions: - writeback_inodes_sb(), which only attempts to writeback dirty inodes on this super_block, for WB_SYNC_NONE writeout. - sync_inodes_sb(), which writes out all dirty inodes on this super_block and also waits for the IO to complete. Acked-by: Jan Kara Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 70 +++++++++++++++++++++++++++++++++---------------------- 1 file changed, 42 insertions(+), 28 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index c54226be5294..271e5f44e871 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -458,8 +458,8 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * on the writer throttling path, and we get decent balancing between many * throttled threads: we don't want them all piling up on inode_sync_wait. */ -void generic_sync_sb_inodes(struct super_block *sb, - struct writeback_control *wbc) +static void generic_sync_sb_inodes(struct super_block *sb, + struct writeback_control *wbc) { const unsigned long start = jiffies; /* livelock avoidance */ int sync = wbc->sync_mode == WB_SYNC_ALL; @@ -593,13 +593,6 @@ void generic_sync_sb_inodes(struct super_block *sb, return; /* Leave any unwritten inodes on s_io */ } -EXPORT_SYMBOL_GPL(generic_sync_sb_inodes); - -static void sync_sb_inodes(struct super_block *sb, - struct writeback_control *wbc) -{ - generic_sync_sb_inodes(sb, wbc); -} /* * Start writeback of dirty pagecache data against all unlocked inodes. @@ -640,7 +633,7 @@ restart: */ if (down_read_trylock(&sb->s_umount)) { if (sb->s_root) - sync_sb_inodes(sb, wbc); + generic_sync_sb_inodes(sb, wbc); up_read(&sb->s_umount); } spin_lock(&sb_lock); @@ -653,35 +646,56 @@ restart: spin_unlock(&sb_lock); } -/* - * writeback and wait upon the filesystem's dirty inodes. The caller will - * do this in two passes - one to write, and one to wait. - * - * A finite limit is set on the number of pages which will be written. - * To prevent infinite livelock of sys_sync(). +/** + * writeback_inodes_sb - writeback dirty inodes from given super_block + * @sb: the superblock * - * We add in the number of potentially dirty inodes, because each inode write - * can dirty pagecache in the underlying blockdev. + * 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 + * for IO completion of submitted IO. The number of pages submitted is + * returned. */ -void sync_inodes_sb(struct super_block *sb, int wait) +long writeback_inodes_sb(struct super_block *sb) { struct writeback_control wbc = { - .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, + .sync_mode = WB_SYNC_NONE, .range_start = 0, .range_end = LLONG_MAX, }; + unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); + unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); + long nr_to_write; - if (!wait) { - unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); - unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); - - wbc.nr_to_write = nr_dirty + nr_unstable + + nr_to_write = nr_dirty + nr_unstable + (inodes_stat.nr_inodes - inodes_stat.nr_unused); - } else - wbc.nr_to_write = LONG_MAX; /* doesn't actually matter */ - sync_sb_inodes(sb, &wbc); + wbc.nr_to_write = nr_to_write; + generic_sync_sb_inodes(sb, &wbc); + return nr_to_write - wbc.nr_to_write; +} +EXPORT_SYMBOL(writeback_inodes_sb); + +/** + * sync_inodes_sb - sync sb inode pages + * @sb: the superblock + * + * This function writes and waits on any dirty inode belonging to this + * super_block. The number of pages synced is returned. + */ +long sync_inodes_sb(struct super_block *sb) +{ + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + .range_start = 0, + .range_end = LLONG_MAX, + }; + long nr_to_write = LONG_MAX; /* doesn't actually matter */ + + wbc.nr_to_write = nr_to_write; + generic_sync_sb_inodes(sb, &wbc); + return nr_to_write - wbc.nr_to_write; } +EXPORT_SYMBOL(sync_inodes_sb); /** * write_inode_now - write an inode to disk -- cgit v1.2.3-55-g7522