From 8786fde8421ce755a842051f9528674a1b1f0b9a Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Sat, 22 Jan 2022 20:54:52 +0000 Subject: Convert NFS from readpages to readahead NFS is one of the last two users of the deprecated ->readpages aop. This conversion looks straightforward, but I have only compile-tested it. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Trond Myklebust --- fs/nfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/file.c') diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 76d76acbc594..4d681683d13c 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -514,7 +514,7 @@ static void nfs_swap_deactivate(struct file *file) const struct address_space_operations nfs_file_aops = { .readpage = nfs_readpage, - .readpages = nfs_readpages, + .readahead = nfs_readahead, .set_page_dirty = __set_page_dirty_nobuffers, .writepage = nfs_writepage, .writepages = nfs_writepages, -- cgit v1.2.3 From 944d95f766c6fe97fa358c661281a741758cee7e Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 7 Mar 2022 10:41:44 +1100 Subject: NFS: remove IS_SWAPFILE hack This code is pointless as IS_SWAPFILE is always defined. So remove it. Suggested-by: Mark Hemment Reviewed-by: Christoph Hellwig Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust --- fs/nfs/file.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'fs/nfs/file.c') diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 4d681683d13c..93c01aaa0a8d 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -44,11 +44,6 @@ static const struct vm_operations_struct nfs_file_vm_ops; -/* Hack for future NFS swap support */ -#ifndef IS_SWAPFILE -# define IS_SWAPFILE(inode) (0) -#endif - int nfs_check_flags(int flags) { if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT)) -- cgit v1.2.3 From 4dc73c679114a2f408567e2e44770ed934190db2 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 7 Mar 2022 10:41:44 +1100 Subject: NFSv4: keep state manager thread active if swap is enabled If we are swapping over NFSv4, we may not be able to allocate memory to start the state-manager thread at the time when we need it. So keep it always running when swap is enabled, and just signal it to start. This requires updating and testing the cl_swapper count on the root rpc_clnt after following all ->cl_parent links. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust --- fs/nfs/file.c | 15 ++++++++++++--- fs/nfs/nfs4_fs.h | 1 + fs/nfs/nfs4proc.c | 20 ++++++++++++++++++++ fs/nfs/nfs4state.c | 40 +++++++++++++++++++++++++++++++++------- include/linux/nfs_xdr.h | 2 ++ net/sunrpc/clnt.c | 2 ++ 6 files changed, 70 insertions(+), 10 deletions(-) (limited to 'fs/nfs/file.c') diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 93c01aaa0a8d..d31bc430dce3 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -483,8 +483,9 @@ static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, { unsigned long blocks; long long isize; - struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); - struct inode *inode = file->f_mapping->host; + struct inode *inode = file_inode(file); + struct rpc_clnt *clnt = NFS_CLIENT(inode); + struct nfs_client *cl = NFS_SERVER(inode)->nfs_client; spin_lock(&inode->i_lock); blocks = inode->i_blocks; @@ -497,14 +498,22 @@ static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, *span = sis->pages; + + if (cl->rpc_ops->enable_swap) + cl->rpc_ops->enable_swap(inode); + return rpc_clnt_swap_activate(clnt); } static void nfs_swap_deactivate(struct file *file) { - struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); + struct inode *inode = file_inode(file); + struct rpc_clnt *clnt = NFS_CLIENT(inode); + struct nfs_client *cl = NFS_SERVER(inode)->nfs_client; rpc_clnt_swap_deactivate(clnt); + if (cl->rpc_ops->disable_swap) + cl->rpc_ops->disable_swap(file_inode(file)); } const struct address_space_operations nfs_file_aops = { diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 84f39b6f1b1e..79df6e83881b 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -42,6 +42,7 @@ enum nfs4_client_state { NFS4CLNT_LEASE_MOVED, NFS4CLNT_DELEGATION_EXPIRED, NFS4CLNT_RUN_MANAGER, + NFS4CLNT_MANAGER_AVAILABLE, NFS4CLNT_RECALL_RUNNING, NFS4CLNT_RECALL_ANY_LAYOUT_READ, NFS4CLNT_RECALL_ANY_LAYOUT_RW, diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index fd8eece12e94..dd7a4c2a3f05 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -10468,6 +10468,24 @@ static ssize_t nfs4_listxattr(struct dentry *dentry, char *list, size_t size) return error + error2 + error3; } +static void nfs4_enable_swap(struct inode *inode) +{ + /* The state manager thread must always be running. + * It will notice the client is a swapper, and stay put. + */ + struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; + + nfs4_schedule_state_manager(clp); +} + +static void nfs4_disable_swap(struct inode *inode) +{ + /* The state manager thread will now exit once it is + * woken. + */ + wake_up_var(&NFS_SERVER(inode)->nfs_client->cl_state); +} + static const struct inode_operations nfs4_dir_inode_operations = { .create = nfs_create, .lookup = nfs_lookup, @@ -10545,6 +10563,8 @@ const struct nfs_rpc_ops nfs_v4_clientops = { .create_server = nfs4_create_server, .clone_server = nfs_clone_server, .discover_trunking = nfs4_discover_trunking, + .enable_swap = nfs4_enable_swap, + .disable_swap = nfs4_disable_swap, }; static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = { diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 58054dfdf2b0..4b2ea239a537 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1207,10 +1207,17 @@ void nfs4_schedule_state_manager(struct nfs_client *clp) { struct task_struct *task; char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1]; + struct rpc_clnt *cl = clp->cl_rpcclient; + + while (cl != cl->cl_parent) + cl = cl->cl_parent; set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state); - if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0) + if (test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) != 0) { + wake_up_var(&clp->cl_state); return; + } + set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state); __module_get(THIS_MODULE); refcount_inc(&clp->cl_count); @@ -1226,6 +1233,7 @@ void nfs4_schedule_state_manager(struct nfs_client *clp) printk(KERN_ERR "%s: kthread_run: %ld\n", __func__, PTR_ERR(task)); nfs4_clear_state_manager_bit(clp); + clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); nfs_put_client(clp); module_put(THIS_MODULE); } @@ -2680,12 +2688,8 @@ static void nfs4_state_manager(struct nfs_client *clp) clear_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state); } - /* Did we race with an attempt to give us more work? */ - if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state)) - return; - if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0) - return; - memflags = memalloc_nofs_save(); + return; + } while (refcount_read(&clp->cl_count) > 1 && !signalled()); goto out_drain; @@ -2706,9 +2710,31 @@ out_drain: static int nfs4_run_state_manager(void *ptr) { struct nfs_client *clp = ptr; + struct rpc_clnt *cl = clp->cl_rpcclient; + + while (cl != cl->cl_parent) + cl = cl->cl_parent; allow_signal(SIGKILL); +again: + set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state); nfs4_state_manager(clp); + if (atomic_read(&cl->cl_swapper)) { + wait_var_event_interruptible(&clp->cl_state, + test_bit(NFS4CLNT_RUN_MANAGER, + &clp->cl_state)); + if (atomic_read(&cl->cl_swapper) && + test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state)) + goto again; + /* Either no longer a swapper, or were signalled */ + } + clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); + + if (refcount_read(&clp->cl_count) > 1 && !signalled() && + test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) && + !test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state)) + goto again; + nfs_put_client(clp); module_put_and_kthread_exit(0); return 0; diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 82f7c2730b9a..49ba486aea5f 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -1797,6 +1797,8 @@ struct nfs_rpc_ops { struct nfs_server *(*clone_server)(struct nfs_server *, struct nfs_fh *, struct nfs_fattr *, rpc_authflavor_t); int (*discover_trunking)(struct nfs_server *, struct nfs_fh *); + void (*enable_swap)(struct inode *inode); + void (*disable_swap)(struct inode *inode); }; /* diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 4117ea4caa2e..0f54a56d19d2 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -3069,6 +3069,8 @@ rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt, int rpc_clnt_swap_activate(struct rpc_clnt *clnt) { + while (clnt != clnt->cl_parent) + clnt = clnt->cl_parent; if (atomic_inc_return(&clnt->cl_swapper) == 1) return rpc_clnt_iterate_for_each_xprt(clnt, rpc_clnt_swap_activate_callback, NULL); -- cgit v1.2.3 From 64158668ac8b31626a8ce48db4cad08496eb8340 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 7 Mar 2022 10:41:44 +1100 Subject: NFS: swap IO handling is slightly different for O_DIRECT IO 1/ Taking the i_rwsem for swap IO triggers lockdep warnings regarding possible deadlocks with "fs_reclaim". These deadlocks could, I believe, eventuate if a buffered read on the swapfile was attempted. We don't need coherence with the page cache for a swap file, and buffered writes are forbidden anyway. There is no other need for i_rwsem during direct IO. So never take it for swap_rw() 2/ generic_write_checks() explicitly forbids writes to swap, and performs checks that are not needed for swap. So bypass it for swap_rw(). Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust --- fs/nfs/direct.c | 42 ++++++++++++++++++++++++++++-------------- fs/nfs/file.c | 4 ++-- include/linux/nfs_fs.h | 8 ++++---- 3 files changed, 34 insertions(+), 20 deletions(-) (limited to 'fs/nfs/file.c') diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index eabfdab543c8..04aaf39a05cb 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -173,8 +173,8 @@ ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE); if (iov_iter_rw(iter) == READ) - return nfs_file_direct_read(iocb, iter); - return nfs_file_direct_write(iocb, iter); + return nfs_file_direct_read(iocb, iter, true); + return nfs_file_direct_write(iocb, iter, true); } static void nfs_direct_release_pages(struct page **pages, unsigned int npages) @@ -425,6 +425,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, * nfs_file_direct_read - file direct read operation for NFS files * @iocb: target I/O control block * @iter: vector of user buffers into which to read data + * @swap: flag indicating this is swap IO, not O_DIRECT IO * * We use this function for direct reads instead of calling * generic_file_aio_read() in order to avoid gfar's check to see if @@ -440,7 +441,8 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, * client must read the updated atime from the server back into its * cache. */ -ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter) +ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter, + bool swap) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; @@ -482,12 +484,14 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter) if (iter_is_iovec(iter)) dreq->flags = NFS_ODIRECT_SHOULD_DIRTY; - nfs_start_io_direct(inode); + if (!swap) + nfs_start_io_direct(inode); NFS_I(inode)->read_io += count; requested = nfs_direct_read_schedule_iovec(dreq, iter, iocb->ki_pos); - nfs_end_io_direct(inode); + if (!swap) + nfs_end_io_direct(inode); if (requested > 0) { result = nfs_direct_wait(dreq); @@ -876,6 +880,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, * nfs_file_direct_write - file direct write operation for NFS files * @iocb: target I/O control block * @iter: vector of user buffers from which to write data + * @swap: flag indicating this is swap IO, not O_DIRECT IO * * We use this function for direct writes instead of calling * generic_file_aio_write() in order to avoid taking the inode @@ -892,7 +897,8 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, * Note that O_APPEND is not supported for NFS direct writes, as there * is no atomic O_APPEND write facility in the NFS protocol. */ -ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter) +ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter, + bool swap) { ssize_t result, requested; size_t count; @@ -906,7 +912,11 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter) dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n", file, iov_iter_count(iter), (long long) iocb->ki_pos); - result = generic_write_checks(iocb, iter); + if (swap) + /* bypass generic checks */ + result = iov_iter_count(iter); + else + result = generic_write_checks(iocb, iter); if (result <= 0) return result; count = result; @@ -937,16 +947,20 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter) dreq->iocb = iocb; pnfs_init_ds_commit_info_ops(&dreq->ds_cinfo, inode); - nfs_start_io_direct(inode); + if (swap) { + requested = nfs_direct_write_schedule_iovec(dreq, iter, pos); + } else { + nfs_start_io_direct(inode); - requested = nfs_direct_write_schedule_iovec(dreq, iter, pos); + requested = nfs_direct_write_schedule_iovec(dreq, iter, pos); - if (mapping->nrpages) { - invalidate_inode_pages2_range(mapping, - pos >> PAGE_SHIFT, end); - } + if (mapping->nrpages) { + invalidate_inode_pages2_range(mapping, + pos >> PAGE_SHIFT, end); + } - nfs_end_io_direct(inode); + nfs_end_io_direct(inode); + } if (requested > 0) { result = nfs_direct_wait(dreq); diff --git a/fs/nfs/file.c b/fs/nfs/file.c index d31bc430dce3..81c80548a5c6 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -157,7 +157,7 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to) ssize_t result; if (iocb->ki_flags & IOCB_DIRECT) - return nfs_file_direct_read(iocb, to); + return nfs_file_direct_read(iocb, to, false); dprintk("NFS: read(%pD2, %zu@%lu)\n", iocb->ki_filp, @@ -623,7 +623,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from) return result; if (iocb->ki_flags & IOCB_DIRECT) - return nfs_file_direct_write(iocb, from); + return nfs_file_direct_write(iocb, from, false); dprintk("NFS: write(%pD2, %zu@%Ld)\n", file, iov_iter_count(from), (long long) iocb->ki_pos); diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 9074ed0b65aa..c47c448befc8 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -508,10 +508,10 @@ static inline const struct cred *nfs_file_cred(struct file *file) * linux/fs/nfs/direct.c */ extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *); -extern ssize_t nfs_file_direct_read(struct kiocb *iocb, - struct iov_iter *iter); -extern ssize_t nfs_file_direct_write(struct kiocb *iocb, - struct iov_iter *iter); +ssize_t nfs_file_direct_read(struct kiocb *iocb, + struct iov_iter *iter, bool swap); +ssize_t nfs_file_direct_write(struct kiocb *iocb, + struct iov_iter *iter, bool swap); /* * linux/fs/nfs/dir.c -- cgit v1.2.3