From 967bcc91b044936e85dbb5848952dc1335a846f4 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 19 Jun 2018 15:08:02 +0100 Subject: gfs2: iomap direct I/O support The page unmapping previously done in gfs2_direct_IO is now done generically in iomap_dio_rw. Signed-off-by: Andreas Gruenbacher Reviewed-by: Bob Peterson --- fs/gfs2/aops.c | 100 ++------------------------------------------------------- 1 file changed, 2 insertions(+), 98 deletions(-) (limited to 'fs/gfs2/aops.c') diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index ecfbca9c88ff..1054cc4a96db 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -84,12 +84,6 @@ static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock, return 0; } -static int gfs2_get_block_direct(struct inode *inode, sector_t lblock, - struct buffer_head *bh_result, int create) -{ - return gfs2_block_map(inode, lblock, bh_result, 0); -} - /** * gfs2_writepage_common - Common bits of writepage * @page: The page to be written @@ -1024,96 +1018,6 @@ out: try_to_release_page(page, 0); } -/** - * gfs2_ok_for_dio - check that dio is valid on this file - * @ip: The inode - * @offset: The offset at which we are reading or writing - * - * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o) - * 1 (to accept the i/o request) - */ -static int gfs2_ok_for_dio(struct gfs2_inode *ip, loff_t offset) -{ - /* - * Should we return an error here? I can't see that O_DIRECT for - * a stuffed file makes any sense. For now we'll silently fall - * back to buffered I/O - */ - if (gfs2_is_stuffed(ip)) - return 0; - - if (offset >= i_size_read(&ip->i_inode)) - return 0; - return 1; -} - - - -static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) -{ - struct file *file = iocb->ki_filp; - struct inode *inode = file->f_mapping->host; - struct address_space *mapping = inode->i_mapping; - struct gfs2_inode *ip = GFS2_I(inode); - loff_t offset = iocb->ki_pos; - struct gfs2_holder gh; - int rv; - - /* - * Deferred lock, even if its a write, since we do no allocation - * on this path. All we need change is atime, and this lock mode - * ensures that other nodes have flushed their buffered read caches - * (i.e. their page cache entries for this inode). We do not, - * unfortunately have the option of only flushing a range like - * the VFS does. - */ - gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh); - rv = gfs2_glock_nq(&gh); - if (rv) - goto out_uninit; - rv = gfs2_ok_for_dio(ip, offset); - if (rv != 1) - goto out; /* dio not valid, fall back to buffered i/o */ - - /* - * Now since we are holding a deferred (CW) lock at this point, you - * might be wondering why this is ever needed. There is a case however - * where we've granted a deferred local lock against a cached exclusive - * glock. That is ok provided all granted local locks are deferred, but - * it also means that it is possible to encounter pages which are - * cached and possibly also mapped. So here we check for that and sort - * them out ahead of the dio. The glock state machine will take care of - * everything else. - * - * If in fact the cached glock state (gl->gl_state) is deferred (CW) in - * the first place, mapping->nr_pages will always be zero. - */ - if (mapping->nrpages) { - loff_t lstart = offset & ~(PAGE_SIZE - 1); - loff_t len = iov_iter_count(iter); - loff_t end = PAGE_ALIGN(offset + len) - 1; - - rv = 0; - if (len == 0) - goto out; - if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags)) - unmap_shared_mapping_range(ip->i_inode.i_mapping, offset, len); - rv = filemap_write_and_wait_range(mapping, lstart, end); - if (rv) - goto out; - if (iov_iter_rw(iter) == WRITE) - truncate_inode_pages_range(mapping, lstart, end); - } - - rv = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, - gfs2_get_block_direct, NULL, NULL, 0); -out: - gfs2_glock_dq(&gh); -out_uninit: - gfs2_holder_uninit(&gh); - return rv; -} - /** * gfs2_releasepage - free the metadata associated with a page * @page: the page that's being released @@ -1194,7 +1098,7 @@ static const struct address_space_operations gfs2_writeback_aops = { .bmap = gfs2_bmap, .invalidatepage = gfs2_invalidatepage, .releasepage = gfs2_releasepage, - .direct_IO = gfs2_direct_IO, + .direct_IO = noop_direct_IO, .migratepage = buffer_migrate_page, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, @@ -1211,7 +1115,7 @@ static const struct address_space_operations gfs2_ordered_aops = { .bmap = gfs2_bmap, .invalidatepage = gfs2_invalidatepage, .releasepage = gfs2_releasepage, - .direct_IO = gfs2_direct_IO, + .direct_IO = noop_direct_IO, .migratepage = buffer_migrate_page, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, -- cgit v1.2.3