writeback: Move I_DIRTY_PAGES handling (6290be1c) · Commits · 戴 / test

Instead of clearing I_DIRTY_PAGES and resetting it when we didn't succeed in writing them all, just clear the bit only when we succeeded writing all the pages. We also move the clearing of the bit close to other i_state handling to separate it from writeback list handling. This is desirable because list handling will differ for flusher thread and other writeback_single_inode() callers in future. No filesystem plays any tricks with I_DIRTY_PAGES (like checking it in ->writepages or ->write_inode implementation) so this movement is safe. Signed-off-by:

Jan Kara <jack@suse.cz> Signed-off-by:

Fengguang Wu <fengguang.wu@intel.com>

fs/fs-writeback.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -385,7 +385,6 @@ writeback_single_inode(struct inode inode, struct bdi_writeback wb,

		/* Set I_SYNC, reset I_DIRTY_PAGES */
		inode->i_state \|= I_SYNC;
		inode->i_state &= ~I_DIRTY_PAGES;
		spin_unlock(&inode->i_lock);
		spin_unlock(&wb->list_lock);

		@@ -408,6 +407,9 @@ writeback_single_inode(struct inode inode, struct bdi_writeback wb,
		* write_inode()
		*/
		spin_lock(&inode->i_lock);
		/* Clear I_DIRTY_PAGES if we've written out all dirty pages */
		if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
		inode->i_state &= ~I_DIRTY_PAGES;
		dirty = inode->i_state & I_DIRTY;
		inode->i_state &= ~(I_DIRTY_SYNC \| I_DIRTY_DATASYNC);
		spin_unlock(&inode->i_lock);
		@@ -435,7 +437,6 @@ writeback_single_inode(struct inode inode, struct bdi_writeback wb,
		* We didn't write back all the pages. nfs_writepages()
		* sometimes bales out without doing anything.
		*/
		inode->i_state \|= I_DIRTY_PAGES;
		if (wbc->nr_to_write <= 0) {
		/*
		* slice used up: queue for next turn

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