From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: fs: remove noop_set_page_dirty() Use __set_page_dirty_no_writeback() instead. This will set the dirty bit on the page, which will be used to avoid calling set_page_dirty() in the future. It will have no effect on actually writing the page back, as the pages are not on any LRU lists. [akpm@xxxxxxxxxxxxxxxxxxxx: export __set_page_dirty_no_writeback() to modules] Link: https://lkml.kernel.org/r/20210615162342.1669332-6-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/dax/device.c | 2 +- fs/ext2/inode.c | 2 +- fs/ext4/inode.c | 2 +- fs/fuse/dax.c | 2 +- fs/libfs.c | 16 ---------------- fs/xfs/xfs_aops.c | 2 +- include/linux/fs.h | 1 - mm/page-writeback.c | 1 + 8 files changed, 6 insertions(+), 22 deletions(-) --- a/drivers/dax/device.c~fs-remove-noop_set_page_dirty +++ a/drivers/dax/device.c @@ -337,7 +337,7 @@ static unsigned long dax_get_unmapped_ar } static const struct address_space_operations dev_dax_aops = { - .set_page_dirty = noop_set_page_dirty, + .set_page_dirty = __set_page_dirty_no_writeback, .invalidatepage = noop_invalidatepage, }; --- a/fs/ext2/inode.c~fs-remove-noop_set_page_dirty +++ a/fs/ext2/inode.c @@ -992,7 +992,7 @@ const struct address_space_operations ex static const struct address_space_operations ext2_dax_aops = { .writepages = ext2_dax_writepages, .direct_IO = noop_direct_IO, - .set_page_dirty = noop_set_page_dirty, + .set_page_dirty = __set_page_dirty_no_writeback, .invalidatepage = noop_invalidatepage, }; --- a/fs/ext4/inode.c~fs-remove-noop_set_page_dirty +++ a/fs/ext4/inode.c @@ -3701,7 +3701,7 @@ static const struct address_space_operat static const struct address_space_operations ext4_dax_aops = { .writepages = ext4_dax_writepages, .direct_IO = noop_direct_IO, - .set_page_dirty = noop_set_page_dirty, + .set_page_dirty = __set_page_dirty_no_writeback, .bmap = ext4_bmap, .invalidatepage = noop_invalidatepage, .swap_activate = ext4_iomap_swap_activate, --- a/fs/fuse/dax.c~fs-remove-noop_set_page_dirty +++ a/fs/fuse/dax.c @@ -1329,7 +1329,7 @@ bool fuse_dax_inode_alloc(struct super_b static const struct address_space_operations fuse_dax_file_aops = { .writepages = fuse_dax_writepages, .direct_IO = noop_direct_IO, - .set_page_dirty = noop_set_page_dirty, + .set_page_dirty = __set_page_dirty_no_writeback, .invalidatepage = noop_invalidatepage, }; --- a/fs/libfs.c~fs-remove-noop_set_page_dirty +++ a/fs/libfs.c @@ -1171,22 +1171,6 @@ int noop_fsync(struct file *file, loff_t } EXPORT_SYMBOL(noop_fsync); -int noop_set_page_dirty(struct page *page) -{ - /* - * Unlike __set_page_dirty_no_writeback that handles dirty page - * tracking in the page object, dax does all dirty tracking in - * the inode address_space in response to mkwrite faults. In the - * dax case we only need to worry about potentially dirty CPU - * caches, not dirty page cache pages to write back. - * - * This callback is defined to prevent fallback to - * __set_page_dirty_buffers() in set_page_dirty(). - */ - return 0; -} -EXPORT_SYMBOL_GPL(noop_set_page_dirty); - void noop_invalidatepage(struct page *page, unsigned int offset, unsigned int length) { --- a/fs/xfs/xfs_aops.c~fs-remove-noop_set_page_dirty +++ a/fs/xfs/xfs_aops.c @@ -575,7 +575,7 @@ const struct address_space_operations xf const struct address_space_operations xfs_dax_aops = { .writepages = xfs_dax_writepages, .direct_IO = noop_direct_IO, - .set_page_dirty = noop_set_page_dirty, + .set_page_dirty = __set_page_dirty_no_writeback, .invalidatepage = noop_invalidatepage, .swap_activate = xfs_iomap_swapfile_activate, }; --- a/include/linux/fs.h~fs-remove-noop_set_page_dirty +++ a/include/linux/fs.h @@ -3417,7 +3417,6 @@ extern int simple_rename(struct user_nam extern void simple_recursive_removal(struct dentry *, void (*callback)(struct dentry *)); extern int noop_fsync(struct file *, loff_t, loff_t, int); -extern int noop_set_page_dirty(struct page *page); extern void noop_invalidatepage(struct page *page, unsigned int offset, unsigned int length); extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter); --- a/mm/page-writeback.c~fs-remove-noop_set_page_dirty +++ a/mm/page-writeback.c @@ -2417,6 +2417,7 @@ int __set_page_dirty_no_writeback(struct return !TestSetPageDirty(page); return 0; } +EXPORT_SYMBOL(__set_page_dirty_no_writeback); /* * Helper function for set_page_dirty family. _
