On Wed, 2017-04-12 at 12:24 +0200, Jan Kara wrote:
> Allocate struct backing_dev_info separately instead of embedding it
> inside the superblock. This unifies handling of bdi among users.
>
> CC: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> CC: Anna Schumaker <anna.schumaker@xxxxxxxxxx>
> CC: linux-nfs@xxxxxxxxxxxxxxx
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> ---
> fs/nfs/client.c | 10 ----------
> fs/nfs/internal.h | 6 +++---
> fs/nfs/super.c | 34 +++++++++++++++++++---------------
> fs/nfs/write.c | 13 ++++++-------
> include/linux/nfs_fs_sb.h | 1 -
> 5 files changed, 28 insertions(+), 36 deletions(-)
>
> diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> index 390ada8741bc..04d15a0045e3 100644
> --- a/fs/nfs/client.c
> +++ b/fs/nfs/client.c
> @@ -761,9 +761,6 @@ static void nfs_server_set_fsinfo(struct
> nfs_server *server,
> server->rsize = NFS_MAX_FILE_IO_SIZE;
> server->rpages = (server->rsize + PAGE_SIZE - 1) >>
> PAGE_SHIFT;
>
> - server->backing_dev_info.name = "nfs";
> - server->backing_dev_info.ra_pages = server->rpages *
> NFS_MAX_READAHEAD;
> -
> if (server->wsize > max_rpc_payload)
> server->wsize = max_rpc_payload;
> if (server->wsize > NFS_MAX_FILE_IO_SIZE)
> @@ -917,12 +914,6 @@ struct nfs_server *nfs_alloc_server(void)
> return NULL;
> }
>
> - if (bdi_init(&server->backing_dev_info)) {
> - nfs_free_iostats(server->io_stats);
> - kfree(server);
> - return NULL;
> - }
> -
> ida_init(&server->openowner_id);
> ida_init(&server->lockowner_id);
> pnfs_init_server(server);
> @@ -953,7 +944,6 @@ void nfs_free_server(struct nfs_server *server)
> ida_destroy(&server->lockowner_id);
> ida_destroy(&server->openowner_id);
> nfs_free_iostats(server->io_stats);
> - bdi_destroy(&server->backing_dev_info);
> kfree(server);
> nfs_release_automount_timer();
> dprintk("<-- nfs_free_server()\n");
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 7b38fedb7e03..9dc65d7ae754 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -139,7 +139,7 @@ struct nfs_mount_request {
> };
>
> struct nfs_mount_info {
> - void (*fill_super)(struct super_block *, struct
> nfs_mount_info *);
> + int (*fill_super)(struct super_block *, struct
> nfs_mount_info *);
> int (*set_security)(struct super_block *, struct dentry *,
> struct nfs_mount_info *);
> struct nfs_parsed_mount_data *parsed;
> struct nfs_clone_mount *cloned;
> @@ -407,7 +407,7 @@ struct dentry *nfs_fs_mount(struct
> file_system_type *, int, const char *, void *
> struct dentry * nfs_xdev_mount_common(struct file_system_type *,
> int,
> const char *, struct nfs_mount_info *);
> void nfs_kill_super(struct super_block *);
> -void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
> +int nfs_fill_super(struct super_block *, struct nfs_mount_info *);
>
> extern struct rpc_stat nfs_rpcstat;
>
> @@ -458,7 +458,7 @@ extern void nfs_read_prepare(struct rpc_task
> *task, void *calldata);
> extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor
> *pgio);
>
> /* super.c */
> -void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
> +int nfs_clone_super(struct super_block *, struct nfs_mount_info *);
> void nfs_umount_begin(struct super_block *);
> int nfs_statfs(struct dentry *, struct kstatfs *);
> int nfs_show_options(struct seq_file *, struct dentry *);
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index 54e0f9f2dd94..8d97aa70407e 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -2315,18 +2315,17 @@ inline void nfs_initialise_sb(struct
> super_block *sb)
> sb->s_blocksize = nfs_block_bits(server->wsize,
> &sb-
> >s_blocksize_bits);
>
> - sb->s_bdi = &server->backing_dev_info;
> -
> nfs_super_set_maxbytes(sb, server->maxfilesize);
> }
>
> /*
> * Finish setting up an NFS2/3 superblock
> */
> -void nfs_fill_super(struct super_block *sb, struct nfs_mount_info
> *mount_info)
> +int nfs_fill_super(struct super_block *sb, struct nfs_mount_info
> *mount_info)
> {
> struct nfs_parsed_mount_data *data = mount_info->parsed;
> struct nfs_server *server = NFS_SB(sb);
> + int ret;
>
> sb->s_blocksize_bits = 0;
> sb->s_blocksize = 0;
> @@ -2344,13 +2343,21 @@ void nfs_fill_super(struct super_block *sb,
> struct nfs_mount_info *mount_info)
> }
>
> nfs_initialise_sb(sb);
> +
> + ret = super_setup_bdi_name(sb, "%u:%u", MAJOR(server-
> >s_dev),
> + MINOR(server->s_dev));
> + if (ret)
> + return ret;
> + sb->s_bdi->ra_pages = server->rpages * NFS_MAX_READAHEAD;
> + return 0;
> +
> }
> EXPORT_SYMBOL_GPL(nfs_fill_super);
>
> /*
> * Finish setting up a cloned NFS2/3/4 superblock
> */
> -void nfs_clone_super(struct super_block *sb, struct nfs_mount_info
> *mount_info)
> +int nfs_clone_super(struct super_block *sb, struct nfs_mount_info
> *mount_info)
> {
> const struct super_block *old_sb = mount_info->cloned->sb;
> struct nfs_server *server = NFS_SB(sb);
> @@ -2370,6 +2377,11 @@ void nfs_clone_super(struct super_block *sb,
> struct nfs_mount_info *mount_info)
> }
>
> nfs_initialise_sb(sb);
> +
> + sb->s_bdi = bdi_get(old_sb->s_bdi);
> + sb->s_iflags |= SB_I_DYNBDI;
> +
> + return 0;
> }
>
> static int nfs_compare_mount_options(const struct super_block *s,
> const struct nfs_server *b, int flags)
> @@ -2522,11 +2534,6 @@ static void nfs_get_cache_cookie(struct
> super_block *sb,
> }
> #endif
>
> -static int nfs_bdi_register(struct nfs_server *server)
> -{
> - return bdi_register_dev(&server->backing_dev_info, server-
> >s_dev);
> -}
> -
> int nfs_set_sb_security(struct super_block *s, struct dentry
> *mntroot,
> struct nfs_mount_info *mount_info)
> {
> @@ -2594,17 +2601,14 @@ struct dentry *nfs_fs_mount_common(struct
> nfs_server *server,
> nfs_free_server(server);
> server = NULL;
> } else {
> - error = nfs_bdi_register(server);
> - if (error) {
> - mntroot = ERR_PTR(error);
> - goto error_splat_super;
> - }
> server->super = s;
> }
>
> if (!s->s_root) {
> /* initial superblock/root creation */
> - mount_info->fill_super(s, mount_info);
> + error = mount_info->fill_super(s, mount_info);
> + if (error)
> + goto error_splat_super;
> nfs_get_cache_cookie(s, mount_info->parsed,
> mount_info->cloned);
> }
>
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index abb2c8a3be42..cc341fc7fd44 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -263,16 +263,15 @@ int nfs_congestion_kb;
>
> static void nfs_set_page_writeback(struct page *page)
> {
> - struct nfs_server *nfss =
> NFS_SERVER(page_file_mapping(page)->host);
> + struct inode *inode = page_file_mapping(page)->host;
> + struct nfs_server *nfss = NFS_SERVER(inode);
> int ret = test_set_page_writeback(page);
>
> WARN_ON_ONCE(ret != 0);
>
> if (atomic_long_inc_return(&nfss->writeback) >
> - NFS_CONGESTION_ON_THRESH) {
> - set_bdi_congested(&nfss->backing_dev_info,
> - BLK_RW_ASYNC);
> - }
> + NFS_CONGESTION_ON_THRESH)
> + set_bdi_congested(inode_to_bdi(inode),
> BLK_RW_ASYNC);
> }
>
> static void nfs_end_page_writeback(struct nfs_page *req)
> @@ -285,7 +284,7 @@ static void nfs_end_page_writeback(struct
> nfs_page *req)
>
> end_page_writeback(req->wb_page);
> if (atomic_long_dec_return(&nfss->writeback) <
> NFS_CONGESTION_OFF_THRESH)
> - clear_bdi_congested(&nfss->backing_dev_info,
> BLK_RW_ASYNC);
> + clear_bdi_congested(inode_to_bdi(inode),
> BLK_RW_ASYNC);
> }
>
>
> @@ -1808,7 +1807,7 @@ static void nfs_commit_release_pages(struct
> nfs_commit_data *data)
> }
> nfss = NFS_SERVER(data->inode);
> if (atomic_long_read(&nfss->writeback) <
> NFS_CONGESTION_OFF_THRESH)
> - clear_bdi_congested(&nfss->backing_dev_info,
> BLK_RW_ASYNC);
> + clear_bdi_congested(inode_to_bdi(data->inode),
> BLK_RW_ASYNC);
>
> nfs_init_cinfo(&cinfo, data->inode, data->dreq);
> nfs_commit_end(cinfo.mds);
> diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
> index b34097c67848..e1502c55741e 100644
> --- a/include/linux/nfs_fs_sb.h
> +++ b/include/linux/nfs_fs_sb.h
> @@ -133,7 +133,6 @@ struct nfs_server {
> struct rpc_clnt * client_acl; /* ACL RPC
> client handle */
> struct nlm_host *nlm_host; /* NLM
> client handle */
> struct nfs_iostats __percpu *io_stats; /* I/O
> statistics */
> - struct backing_dev_info backing_dev_info;
> atomic_long_t writeback; /* number of
> writeback pages */
> int flags; /* various
> flags */
> unsigned int caps; /* server
> capabilities */
Acked-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
--
Trond Myklebust
Linux NFS client maintainer, PrimaryData
trond.myklebust@xxxxxxxxxxxxxxx
