From 4b60c0ff2f2021ab99b7fb9da63b7ed1579ef1d8 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 9 May 2022 18:20:48 -0700 Subject: mm: move responsibility for setting SWP_FS_OPS to ->swap_activate If a filesystem wishes to handle all swap IO itself (via ->direct_IO and ->readpage), rather than just providing devices addresses for submit_bio(), SWP_FS_OPS must be set. Currently the protocol for setting this it to have ->swap_activate return zero. In that case SWP_FS_OPS is set, and add_swap_extent() is called for the entire file. This is a little clumsy as different return values for ->swap_activate have quite different meanings, and it makes it hard to search for which filesystems require SWP_FS_OPS to be set. So remove the special meaning of a zero return, and require the filesystem to set SWP_FS_OPS if it so desires, and to always call add_swap_extent() as required. Currently only NFS and CIFS return zero for add_swap_extent(). Link: https://lkml.kernel.org/r/164859778123.29473.17908205846599043598.stgit@noble.brown Signed-off-by: NeilBrown Reviewed-by: Christoph Hellwig Tested-by: David Howells Tested-by: Geert Uytterhoeven Cc: Hugh Dickins Cc: Mel Gorman Cc: Trond Myklebust Cc: Miaohe Lin Signed-off-by: Andrew Morton --- fs/cifs/file.c | 3 ++- fs/nfs/file.c | 14 ++++++++++++-- 2 files changed, 14 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/cifs/file.c b/fs/cifs/file.c index d511a78383c3..14d29404c834 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -4933,7 +4933,8 @@ static int cifs_swap_activate(struct swap_info_struct *sis, * from reading or writing the file */ - return 0; + sis->flags |= SWP_FS_OPS; + return add_swap_extent(sis, 0, sis->max, 0); } static void cifs_swap_deactivate(struct file *file) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 150b7fa8f0a7..a3a073604070 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -483,6 +483,7 @@ static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, { unsigned long blocks; long long isize; + int ret; struct inode *inode = file_inode(file); struct rpc_clnt *clnt = NFS_CLIENT(inode); struct nfs_client *cl = NFS_SERVER(inode)->nfs_client; @@ -496,13 +497,22 @@ static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, return -EINVAL; } - *span = sis->pages; + ret = rpc_clnt_swap_activate(clnt); + if (ret) + return ret; + ret = add_swap_extent(sis, 0, sis->max, 0); + if (ret < 0) { + rpc_clnt_swap_deactivate(clnt); + return ret; + } + *span = sis->pages; if (cl->rpc_ops->enable_swap) cl->rpc_ops->enable_swap(inode); - return rpc_clnt_swap_activate(clnt); + sis->flags |= SWP_FS_OPS; + return ret; } static void nfs_swap_deactivate(struct file *file) -- cgit v1.2.3